wylfa nuclear power station - hse

WYLFA NUCLEAR POWER STATION

ENVIRONMENTAL STATEMENT 2013 UPDATE

WYLFA NUCLEAR POWER STATION

ENVIRONMENTAL STATEMENT 2013 UPDATE

in Support of the Application to Decommission Wylfa Nuclear Power Station as Required by Statutory Instrument 1999 No. 2892: Nuclear Reactors (Environmental Impact Assessment for

Decommissioning) Regulations 1999 (as amended)

Issue One

March 2013

Published in the United Kingdom by Magnox Limited, Wylfa Nuclear Power Station, nr Cemaes Village, Isle of Anglesey, LL67 0DH. All rights reserved. No part of this publication may be: (i) reproduced used, dealt with, possessed or transmitted in any form or by any means, including photocopying and recording, without the written permission of the copyright holder; or (ii) used, dealt with or possessed in any way whatsoever, where such use, dealing with or possession will or may infringe any intellectual property rights of the publisher (including any trade marks, patents or patents pending, design right (registered or unregistered), know how, show how, moral rights or any licence held by the publisher with a third party). Application for permission to reproduce, transmit, use, deal or possess should be addressed to the publisher. Such written permission must also be obtained before any part of this publication is stored in a retrieval system of any nature. Printed copies of the Welsh version this document can be obtained from the following address: Document Centre, Magnox, Wylfa Power Station, nr Cemaes Village, Isle of Anglesey, LL67 0DH. © Magnox Ltd 2013

Wylfa Power Station ES 2013 Update

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Wylfa Power Station ES 2013 Update of 119

TABLE OF CONTENTS

1. INTRODUCTION 7 1.1. Background to the Application to Decommission Wylfa 8

1.2. Approach to Gaining Consent 8

1.3. Pre-Application Opinion 9

1.4. Magnox response to the PAO 10

2. STAKEHOLDER ENGAGEMENT 12

3. METHOD FOR THE 2013 UPDATE 13

4. THE WYLFA SITE 15 4.1. The Site Surroundings 16

5. THE DECOMMISSIONING PROJECT 19 5.1. The Decommissioning Proposals in Further Detail 19

5.2. How Will the Work be Managed? 23

6. CHANGE IN DECOMMISSIONING STRATEGY SINCE 2008 26

7. THE ROLE OF THE ENVIRONMENTAL MANAGEMENT PLAN (EMP) 28

8. DEVELOPMENT PROJECTS IN THE WYLFA AREA 29 8.1. Nuclear New-Build 29

8.2. Other Infrastructure projects in Anglesey 30

8.3. Marine Current Turbines 30

9. OVERVIEW OF UK GOVERNMENT AND MAGNOX DECOMMISSIONING AND WASTE MANAGEMENT STRATEGIES 32

10. THE LEGISLATIVE AND REGULATORY FRAMEWORK 33

11. ALTERNATIVES 37

12. THE ENVIRONMENTAL IMPACT ASSESSMENT 38

13. AIR QUALITY AND DUST 39 13.1. Overview of the 2008 Assessment 39

13.2. The Outcome of the 2013 Update 39

13.3. Conclusions 41

14. ARCHAEOLOGY AND CULTURAL HERITAGE 42 14.1. Overview of the 2008 Assessment 42



15. ECOLOGY 45 15.1. Overview of the 2008 Assessment 45


15.3. Habitats Regulation Assessment (HRA) 50


16. GEOLOGY, HYDROGEOLOGY AND SOILS 52 16.1. Overview of the 2008 Assessment 52



17. LANDSCAPE AND VISUAL 57 17.1. Overview of the 2008 Assessment 57



18. NOISE AND VIBRATION 63 18.1. Overview of the 2008 Assessment 63


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19. SOCIO–ECONOMIC 68 19.1. Overview of the 2008 Assessment 68


19.3. The Wylfa Station Baseline 73


20. SURFACE WATERS 79 20.1. Overview of the 2008 Assessment 79



21. TRAFFIC AND TRANSPORT 85 21.1. Overview of the 2008 Assessment 85



22. RESIDUAL IMPACTS 97

23. CONCLUSION OF THE 2013 UPDATE 98

APPENDIX 1: CHANGES TO THE PROJECT DESCRIPTION 2008 - 2013 100

APPENDIX 2: BASELINE ENVIRONMENTAL CHANGE 2008 AND 2012 102

APPENDIX 3: SUMMARY OF SIGNIFICANT ADVERSE IMPACTS 2008 - 2013 106

APPENDIX 4: MITIGATION MEASURES 2008 - 2013 111


1. INTRODUCTION

Wylfa Nuclear Power Station (hereafter Wylfa) will cease electricity generation and commence decommissioning by December 20151. In order to decommission, consent is required under Statutory Instrument No. 2892: Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations 1999 (as amended) (hereafter EIADR 99). Wylfa already has a decommissioning consent in place, however as a result of the extension of electricity generation at Wylfa, this consent will expire before decommissioning can commence. The ‘Environmental Statement 2013 Update’ document (this document, hereafter 2013 Update), in combination with supporting documents as described below, forms the basis of a new application to decommission Wylfa under EIADR 99. The 2013 Update brings the 2008 ES up-to-date as required. The 2013 Update is therefore intended to be read in conjunction with the following three supporting documents:

Wylfa Nuclear Power Station: Environmental Statement (2008); Wylfa Nuclear Power Station: Environmental Statement: Supplementary Drawings (2008);

and Wylfa Nuclear Power Station: Environmental Statement: Non-Technical Summary (2008).

The three documents listed above from 2008 comprise the Environmental Statement (ES) that was submitted in support the previous application to decommission Wylfa, and which forms the basis of Wylfa’ s existing decommissioning consent. These three 2008 documents are referred to here as the ‘2008 ES’. The 2008 ES was based upon an Environmental Impact Assessment (EIA) carried out by Magnox North, which is now Magnox Ltd., (hereafter Magnox). The 2013 Update makes reference to Sections, Supplementary Drawings, Figures and Tables supplied in the original 2008 ES, to identify where updates are required, or to identify where additional underpinning details can be found. However the 2013 Update is intended to be a stand-alone document that provides sufficient detail to fully understand the impacts of the revised decommissioning start date upon the original 2008 ES, and which explains and provides all necessary changes required to bring the 2008 ES up-to-date. To avoid any potential confusion, all Tables, Photographs, Boxes and Figures provided in the 2013 Update document are labelled with an ‘A’ (e.g. Table A1) to differentiate them from those in the 2008 ES. An overview of the decommissioning project and Wylfa’s surrounding environment are also presented in the 2013 Update, and any changes from the 2008 ES are identified, and changes are also listed in four Appendices to this document. Other components of the 2008 ES that require update (e.g. Alternatives, Stakeholder Engagement, and Legislation) are also included in 2013 Update, with appropriate revisions provided and explained. The four Appendices to this document list all the changes that have been identified between the 2013 Update and the 2008 ES. These Appendices list changes in the:

Decommissioning project 2008 – 2013; Environmental Baseline 2008 – 20122; Environmental Impact Assessment 2008 – 2013; and Mitigation requirements 2008 – 2013.

For clarity, changes to the decommissioning project are also identified in the text below by footnotes, which link directly to Appendix 1 (Changes to the Project Description 2008 – 2013). The

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1 September 2014 is the current ONR approved date for the end of generation at Wylfa, though work is on-going to extend this to December 2015, assuming the appropriate consents are received.

Wylfa Power Station

2 2012 is used here as it is the latest year for which a full 12 months of data were available.


Structure of the documents that comprise the Submission to support the decommissioning consent application is shown in Figure A1. Figure A1: Document Structure. Red text indicates documentation produced specifically to support the current application, and black text indicates the original 2008 ES. All these documents form the basis of the current application to decommission Wylfa.

1.1. Background to the Application to Decommission Wylfa

In August 2008 Magnox supplied the Health and Safety Executive (HSE)3 with an Environmental Statement (the 2008 ES) to support an application to decommission the site. The 2008 ES reported the findings of an EIA that was carried out to consider the potential environmental effects occurring as a result of the proposed decommissioning project. It identified the adverse or beneficial environmental impacts of the decommissioning project and the proposed measures to be taken to avoid, reduce or offset those adverse impacts. After consideration of the 2008 ES, the HSE granted consent to decommission Wylfa on the 25th of March 2009. A condition of the consent was that decommissioning should commence within five years (i.e. by March 2014). In 2008 it was envisaged that Wylfa would cease electricity generation within five years, although it was at the time recognised that there was a case for extending the period of generation. Since 2008 Magnox has successfully made the case for extending the generating life of Wylfa to beyond 2014. Under current plans Wylfa will therefore not satisfy the condition to commence decommissioning within the five year period and as a result the consent will expire.

1.2. Approach to Gaining Consent

Under EIADR 99, the decommissioning of a nuclear power station requires the consent of the Office for Nuclear Regulation (ONR), which is an agency of the HSE. After consultation with the ONR, Magnox have decided to adopt the following approach to gaining a new consent:

3 Note that as of April 2011 this function is administered on the HSE's behalf by the Office for Nuclear Regulation (ONR).

Review the original 2008 ES to identify any areas that require modification as a result of the revised decommissioning date;

Revise and update the 2008 ES as required, by incorporating any required changes from the above review into a 2013 Update document (this document); and

Re-apply for consent, by submitting the 2013 Update and the original 2008 ES documentation to the ONR.

The review takes full account of proposed new developments in the area, including the proposed new nuclear power station near Wylfa (which is described in more detail below). These are reviewed to determine if they create any cumulative environmental impacts, when considered in combination with the decommissioning proposals at Wylfa. In addition to the above steps, in November 2012 Magnox asked the ONR (as the appropriate agency of the HSE), to provide a Pre-Application Opinion (PAO) on the proposed approach towards gaining consent to decommission Wylfa (in accordance with Regulation 6 of EIADR 99). The output from the PAO, published in February 2013, is described below4.

1.3. Pre-Application Opinion

The HSE’s opinion on the format and content of an application for EIADR consent are included in full below - all italicised text below is extracted directly from the PAO provided by the ONR / HSE. Note that we have used the exact text from the PAO, including the numbering; only italics have been added. The PAO process made reference to a ‘Desktop Review’. Following discussions with Stakeholders following the PAO, Magnox made a decision to name the update document as the Environmental Statement: 2013 Update (this document). It was considered by Magnox and Stakeholders that this terminology was clearer and more appropriate than the term ‘Desktop Review’ as used in the PAO. HSE opinion on the format and content of an application for EIADR consent The Wylfa scoping report presents the proposed format and content of an application submitted to HSE as an application for EIADR consent. The proposed approach is to conduct a ‘desktop review’ to thoroughly review the original ES to bring it up to date, review the proposed decommissioning methods and mitigation measures to be used and address any contemporary issues. HSE accepts this as an appropriate and pragmatic approach.

After due consideration of the desktop review and taking into account comments received from consultees, HSE has identified below a number of specific points and issues that should be addressed in the general update of the ES. It is noted that these should be considered in conjunction with the previous PAO, which contains still pertinent opinion and advice.

a) The desktop review will appropriately review the environmental impact of the

decommissioning work and the required mitigation measures to avoid or minimise any environmental impacts. As indicated in the scoping report it is essential to consider where technology and approaches may have moved on since the original ES was created to ensure that best practice is utilised for the decommissioning works and mitigation measures etc.

b) In relation to mitigation measures it is important that their effectiveness can be judged.

The desktop review should consider where it may be necessary to collect or generate baseline/background data for reference and later comparison as the decommissioning work is underway, for instance to establish background levels of dust and noise on site. Similarly, plans for regular or periodic surveys, e.g. for ecology or wildlife, should be considered.


4 See also http://www.hse.gov.uk/nuclear/nuc28.pdf

Wylfa Power Station


c) The desktop review will appropriately consider the potential impact of the decommissioning project at Wylfa with other large-scale projects on Anglesey. This will mainly cover the likely adjacent development of the proposed new nuclear power station but should also cover other developments such as those that form part of the Anglesey Energy Island Programme, as appropriate. The consideration should include issues such as:

i) Potential for combined and cumulative impact with these other projects ii) Potential synergies between the projects, for instance in traffic management or

utilisation of share facilities such as the marine offloading facility planned for the proposed new nuclear power station

iii) Socio-economic impacts, such as the impact on local jobs, impact on the Welsh language and tourism

Wylfa are encouraged to work with these other projects where possible to share intelligence, best practice and environmental data etc, although it is acknowledged that the extent to which this can be done may be limited due to commercial or legal reasons.

d) There should be a review of the regulatory framework and legislation that applies to the decommissioning project to identify any revised or new legal duties or responsibilities etc. A side-by-side comparison of current and 2009 legislation in a table might be a particularly effective way to present this. Similarly, there are a number of other plans and strategies of relevance to major projects on Anglesey that may be considered in the review as appropriate, examples may include:

i) The Anglesey Landscape Strategy Update 2011 ii) Area of Outstanding Natural Beauty Plan (2009-14) iii) Section 85 of the Countryside and Rights of Way Act 2000

A non-technical summary of the desktop review should be provided (as indicated in EIADR schedule 1).

1.4. Magnox response to the PAO

Each of the specific points raised in the PAO is addressed below, with links to other Sections of this document as appropriate. (a) Use of Technology and Best Practice: Magnox have asked Hyder Consulting (hereafter Hyder) to carry out an independent review of the original 2008 ES (Hyder were not part of the consultant team that carried out the 2008 ES). Hyder have utilised specialists in each topic area to determine if any technical areas of the 2008 ES require updating, to reflect changes in technology, methodology, best practice or to meet other recognised industry standard developments in EIA. (b) Effectiveness of mitigation measures: Magnox agree that it is crucial that assessments of the effectiveness of mitigation measures are underpinned by appropriate baseline data. Magnox has asked the Hyder review team to identify where such surveys are required and when they should be carried out. These are included in this document and shall be included in future editions of the Wylfa’s Environmental Management Plan (EMP); the EMP document is described in Section 7 of this document. (c) Working with other major developments to reduce cumulative impacts, derive synergistic benefits and reduce socio-economic impacts: As described in more detail in Section 8 of this document, nuclear new-build is likely to take place at Wylfa in a few years. Magnox have been working with Horizon Nuclear Power, who own the land surrounding Wylfa, to develop opportunities that benefit both parties. Horizon made the following statement in response to the PAO5 (the text below is directly from the Horizon response, only italics have been added):

5 Horizon Nuclear Power: Response to Magnox Wylfa Nuclear Power station – Pre-Application Opinion Scoping report – Issue 2 – November 2012.

Horizon welcomes the reports commitment to explore opportunities for co-operation between the Magnox Decommissioning project and the Horizon Nuclear Power project, particularly in relation to joint mitigation measures. In order to promote sustainable development we also wish to explore the possibility of using existing Magnox infrastructure for the new build project. We have instigated discussions with Magnox on this issue and look forward to these continuing. The potential opportunities for co-operation to promote sustainable development with Horizon and other major infrastructure projects on Anglesey, is discussed within each topic area in Section 12 of this document. However, at this stage it is recognised that no major infrastructure developments are sufficiently well advanced (see Section 8 of this document) to allow firm commitments to be made. The Hyder review team were also asked to provide current best practice on methods to reduce cumulative impacts. (d) Review of the regulatory framework: This has been undertaken and is included in Section 10 of this document. It should also be noted that the ONR / HSE consider that the original PAO (which is described in the original 2008 ES) remains valid. A Non-Technical Summary of the 2013 Update has also been provided.


Wylfa Power Station

2. STAKEHOLDER ENGAGEMENT

Stakeholder engagement is a key component in the EIA process, ensuring transparency in the project and its impacts, and allowing all stakeholders an opportunity to comment on, and thereby influence the assessment. The Stakeholder Engagement carried out for the 2008 ES is described in Section 3 of that document. This engagement was extensive and comprehensive, and the outputs of which are fully explained in the 2008 ES. For this application, it was concluded that it would not be appropriate to fully repeat this engagement because:

The decommissioning plans have not changed significantly; Local people would be unlikely to want to comment on the same information and proposals

twice; The change to the decommissioning start date is relatively small, and other dates remain

largely unaffected. Instead, stakeholder engagement for this application was carried out through the Site Stakeholder Group (SSG), through internal communications and through adverts in the Wylfa Information Centre. Presentations were given to the SSG on 13th September 2012 and 13th December 2012. On-going consultation will be held with the SSG on the progress of the decommissioning application. The PAO consultation was reported at the SSG and also in the Wylfa Site weekly team brief, and on the Site’s information boards. The PAO was also advertised at the entrance to the Wylfa Information Centre, which is open to the public (See Photograph A1). A meeting with Statutory Consultees, including the Isle of Anglesey County Council (IoACC), Countryside Council for Wales (CCW) and the Environment Agency Wales (EA) was held on the 4th March 2013 to discuss the process for the new application.

Photograph A1: Stakeholder poster at the Wylfa Information Centre


3. METHOD FOR THE 2013 UPDATE

The methods described below were used to determine the on-going validity of the 2008 ES to provide the basis of a new application to decommission Wylfa. The primary purpose of the 2008 ES is to ensure that appropriate mitigation is in place to protect the environment during decommissioning. Therefore to establish the on-going validity of the 2008 ES, it was determined if the revised decommissioning start date:

Results in a revised environmental baseline for the area; Means that new methods for EIA are available; Results in any potential change in cumulative impacts as given in the original 2008 ES, or

in any new cumulative impacts or if there were any potential synergies with new nuclear build or other major surrounding developments;

Results in any new impacts not already assessed in the original 2008 ES; or Requires any change or additions to the proposed mitigation procedures provided in the

original 2008 ES;

This approach was agreed with Hyder (as independent experts) and the ONR. Table A 1 below provides additional detail on how these five ‘tests’ were applied to the 2008 ES. Hyder have produced an independent report on the findings of these tests6 and the relevant details from that report are included in the environmental topic areas (Sections 13 - 21 of this document).

Table A 1: The Tests Applied to the 2008 ES. Validity test Details of the Test

1. New / revised environmental data exists that could affect the assessment

To determine if:

New environmental data not recorded in the 2008 ES had been reported (e.g. new protected species in the area);

Revised environmental data were available (e.g. traffic count data) that were significantly different from the equivalent data in the 2008 ES.

2. New EIA methods are available since the 2008 ES was published that could affect the assessment

To determine if:

There have been any changes to EIA assessment methodology or mitigation technology that could affect the conclusions of the 2008 ES.

3. There are new cumulative impacts not listed in the 2008 ES

To determine if:

There were any opportunities for potential cumulative impacts with any new developments that challenged or invalidated the existing proposed mitigation in the 2008 ES;

There were any potential opportunities for co-operation to promote sustainable development with Horizon and other major infrastructure projects on Anglesey.

4. There are impacts that were not assessed in the 2008 ES

To determine if:

Changes to the decommissioning project resulted in any new or revised impacts that were not assessed in the 2008 ES.

5. The mitigation listed in the 2008 ES is no longer sufficient or appropriate

To determine if:

Additional mitigation is required to protect the environment;

Additional surveys were required prior to, or during

Wylfa Power Station

6Hyder Consulting 2013: Magnox Limited Wylfa EIADR: Review of 2008 ES for Wylfa decommissioning. Report number: 0001-UA005369-UU81R-01-WylfaEIADR.


decommissioning to ensure that the effectiveness of mitigations measures can be demonstrated.

It should also be noted that it will require in the order of 100 years to fully decommission Wylfa (See Section 5) with the first phase of this process being completed by 2025. Given these timescales, it is important that there are mechanisms in place to ensure the on-going validity of the mitigation associated with the decommissioning project. The two mechanisms that exist are:

The Environmental Management Plan (EMP); The legal requirement (under Regulation 13 of EIADR 99) to assess the environmental

impacts of any change to the decommissioning project.

The role of the EMP is discussed in Section 7 below, and changes to the decommissioning project in Section 6 below.


4. THE WYLFA SITE

Wylfa is located on the north coast of the Isle of Anglesey at Wylfa Head, near Cemaes Village7 (see Photograph A2 and Supplementary Drawings Figure WYA/GEN/1). Magnox is the licensee of Wylfa under the Nuclear Installations Act 1965 (as amended). The UK Government’s Nuclear Decommissioning Authority (NDA) owns the site and Magnox manages the site under contract to the NDA. The nuclear licensed site at Wylfa covers approximately 21 hectares8 and can be considered as two parts:

The area within the Inner Security Barrier (ISB); and The conventional area.

Other than these two general areas, outside of the outer security fence are: the jetty, the information centre9, simulator training building, reception centre, contractors car park, the off-site emergency control centre, emergency equipment storage compounds and the 132 kilovolt (kV) and 400 kV electricity substations. The Wylfa Learning & Development Centre is located at Coleg Menai and it is not part of the decommissioning project. These substations provide the electrical connection to the power station site and are owned by National Grid Company. They are located in close proximity to the outer security fence, on land owned by NDA and leased to National Grid Company; the substations are not part of the decommissioning project.

Photograph A2: View of Wylfa Nuclear Power Station and Surrounding Area

The area within the ISB includes a number of buildings with internal plant and structures some of which are either radioactive themselves or which are contaminated with radioactive substances. The main buildings and plant within the ISB are the:

7 To avoid any potential confusion, the term ‘Cemaes Village’ is used when referring to the settlement itself, and ‘Cemaes Bay’ is used in reference to the coastal bay adjacent to the settlement. 8 There has been a change in the landholding from the 2008 ES – See Appendix 1, line 1.

Wylfa Power Station

9 There has been a change in the leasing arrangements for some buildings See Appendix 1, line 2.



Reactor building; Three primary dry storage cells (DSCs) and waste storage vaults; Two secondary DSCs; Primary and diverse discharge fuel routes; and Active effluent treatment plant (AETP) (located within the reactor building).

The reactor building contains two reactors housed in a combined single building, which are of the gas cooled, graphite moderated ‘Magnox’ type10. Each reactor is enclosed in a concrete pressure vessel lined with mild steel. The concrete pressure vessel also acts as the biological shield, which protects workers from the effects of the direct radiation from the reactors themselves. In addition to the fuel (when generating), also contained within the pressure vessel are the four boilers, graphite, control equipment (including control rods and associated mechanisms) and equipment used for monitoring (e.g. temperatures, pressures). Each reactor pressure vessel forms part of the ‘primary circuit’ comprising the pressure vessel and the boilers (heat exchangers). Each reactor has four boilers which are used for heat removal and steam production. Four electrical driven gas circulators on each reactor provide forced CO2 gas circulation, in order to transfer the heat generated within the reactors to the boilers. A significant difference between Wylfa power station and other Magnox reactor power stations is the provision of Dry Storage Cells (DSCs) for spent fuel, which eliminates the need for fuel ponds and associated waste streams. There are five DSCs. The three primary DSCs (1, 2 and 3) can hold about 6500 fuel elements each and are cooled using carbon dioxide. The secondary DSCs (4 and 5) are a later addition and are a different design; being air cooled, they can hold about 29000 fuel elements each. The diverse discharge fuel route allows disposal of fuel directly from DSCs 4 and 5. The conventional area (outside the ISB but within the outer security fence) contains mostly non-radioactive plant and buildings. The main plant and buildings in this area are as follows:

Turbine hall; Cooling water pumphouse; Water treatment plant; Radioactive waste incinerator11; Carbon dioxide storage tanks; Carbon dioxide plant (including vaporisation facilities); Gas turbine plant; Mechanical workshops, stores and engineering facilities; and Administration block and offices.

Of these, the most substantial structure is the turbine hall. Within the turbine hall are four turbo-generator units each of which, when the station is generating, receives incoming steam and rotates the internal mechanism of the alternator (electricity generating) units. Beneath these turbo-generator units are the condensing units, founded on the floor of the turbine hall. Through these condensing units is passed cooling water (drawn from the Irish Sea) that is used to complete the conversion of steam to water before it is transferred back to the boilers. Further detail on the layout, plant and equipment on the site can be found in Part One, Section 4 of the 2008 ES.

4.1. The Site Surroundings

The environmental impacts of the decommissioning project have been considered in the context of the existing site surroundings. The existing site surroundings are described in full in Part One,

10 The term ‘Magnox’ derives from the magnesium alloy cladding material [MAGnesium Non-OXidising alloy] that surrounds the natural uranium fuel within each individual fuel element. 11 Although the active waste incinerator is within the conventional area it is a radiation controlled area (RCA)

Section 4 of the 2008 ES and in the individual technical sections of Part Two of the 2008 ES. A summary of the area surrounding Wylfa is presented in Box A1 below. Box A1: The Area Surrounding Wylfa Main access route: The main vehicular route to and from Wylfa power station site is the A5025

which connects the site to the A5 at Valley and the A55, approximately 20km to the south. To the east, the A5025 connects the power station to Cemaes Village and a number of other settlements on the northern and eastern coast of Anglesey. In both directions this route is predominantly rural in nature but also runs via a number of settlements.

Landscape features: Essentially rocky shoreline to the north west. Wylfa Head to the north east, a level outcrop with craggy shoreline. Area of scrub and woodland to the south east. Area of flat small scale agricultural fields surrounding the site and vegetated area to the south. Close to the coast the land generally comprises rough grazing with exposed rock and gorse thickets. Further inland the land comprises gently undulating, low lying farmland and isolated woodland.

Air Quality: There are currently no Air Quality Management Areas (AQMAs) on the Isle of Anglesey and none pending.

Main surface water feature:

The main surface water feature in the area with the potential to be directly affected by the site is the coastal water of the Irish Sea. It is from here that water is taken for use on the site prior to being discharged back to the sea. There are no significant surface fresh water courses at or within the immediate area to the Wylfa site and as such there are no water quality designations. The nearest major fresh water course is the Afon Wygyr which drains land to the east of the power station and flows into the Irish Sea at Cemaes Village some 2km from the power station. There is a small intermittent stream to the south of the site, which draws on shallow water within the superficial deposits. There are a number of small springs and drainage ditches feeding Tre’r Gof SSSI located to the north-east of the station.

Underlying bedrock: The underlying bedrock is New Harbour Group of the Pre-Cambrian Mona Complex. Wylfa Head and part of the headland to the north-west of the site comprise rocks of the Gwna Group. Within the New Harbour Group there are outcrops of extrusive igneous rock, with one such outcrop cutting across the site to the south of the turbine hall and reactor building.

Major Aquifers: There are no significant aquifers beneath the site.

Minor Aquifers: The New Harbour Group is classified as a minor aquifer as it may contain water where it is fractured, weathered or broken.

Nearest Settlements: Tregele Village 1km south-west. Cemaes Village 2km south-east. Amlwch 9km east. Holyhead (nearest town with over 10,000 inhabitants) 27km south-west.

Designated sites of nature conservation interest:

Tre’r Gof SSSI. Cemlyn Bay SSSI. Ynys Feurig, Cemlyn Bay and The Skerries Special Protection Area (SPA). Cemlyn Bay Special Area of Conservation (SAC).

Designated geological sites of conservation value:

There are no designated geological sites of conservation value on or adjacent to the power station. The nearest is Henborth Site of Special Scientific Interest (designated for its geological features) which is approximately 2km from Wylfa.


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Box A1: The Area Surrounding Wylfa Scheduled Monuments:

There are no Scheduled Ancient Monuments on the power station site. The nearest Scheduled Ancient Monument is a triangular arrangement of Early Bronze age standing stones 2.5km south-west of the site.

Listed Buildings: There are no Listed Buildings within the study area. There are three Listed Buildings 1km south-west of the power station.

Historic Parks and Gardens:

Cestyll Gardens lies within the NDA landholding and is included in the Cadw/ICOMOS Register of Landscapes, Parks and Gardens of Special Historic Interest in Wales.

Historic Battlefields: There are no registered historic battlefields within the study area.

5. THE DECOMMISSIONING PROJECT

The decommissioning project is described in full in Section 6 of the 2008 ES. The project is comprised of three stages. Over a period of about 10 years all the machinery and buildings, except the reactor building, will be dismantled and removed. During this time, referred to as ‘Care and Maintenance Preparations’, the reactor building will be prepared for an extended period of safe storage, known as ‘Care and Maintenance’, until the radioactivity levels inside the reactors will be low enough to simplify their final dismantling. This period of storage ends approximately 85 years after the end of Care and Maintenance Preparations. Following this period, over about 8 years, the reactors and the reactor building will be removed and the site finally cleared; this is known as ‘Final Site Clearance’. Box A2 provides a summary of the three main decommissioning stages. Further information on the decommissioning and waste management strategies, in particular in relation to Government policies, can be found in Part One, Section 5 of the 2008 ES. Reasons for the selection of strategies for the various aspects of the proposals can be found in Part One, Section 7 of the 2008 ES.

Box A2: Summary of the Main Stages of Decommissioning

Care and Maintenance Preparations is the first stage and is estimated to take approximately 10 years to complete. During this stage all of the radioactive and non-radioactive plant and buildings on the site other than the reactor building (and most of its contents) will be dismantled and cleared.

Care and Maintenance is the second stage which, it is proposed, will last for a number of decades, during which no significant dismantling will be carried out. During this time the site will continue to be managed, monitored and maintained in a safe state.

Final Site Clearance is the last stage and expected to take about eight years. This involves the dismantling of the remaining structures on the site, including the reactors, and the clearance of any residual radioactivity to the applicable standards.

5.1. The Decommissioning Proposals in Further Detail

Decommissioning of Wylfa will involve the careful and systematic removal of all plant, equipment and buildings from the site including the nuclear reactors and all wastes. As explained above, it is proposed to do this in three distinct phases. Each phase is now described in further detail. More detailed information on carrying out the decommissioning and waste management works can be found in Part One, Section 6 of the 2008 ES. As explained there, there is greater uncertainty surrounding the exact works that will be carried out during Final Site Clearance than there is for the earlier phases of decommissioning. Such uncertainties for Final Site Clearance include the date that work commences, programme, the location on site of new facilities and the composition of radioactive discharges. Care and Maintenance Preparations The first stage of decommissioning is aimed at placing the site into a state where, although monitoring and maintenance will still be needed, human intervention is minimised. All significant radioactive and non-radioactive buildings and machinery, except the reactor building, will be dismantled. Some partial dismantling and removal of machinery in and around the reactor building will take place but the large items such as the reactors, the concrete bioshields, boilers and the primary DSCs (1, 2 and 3) will not be removed until Final Site Clearance. The secondary DSC (4 and 5) will be demolished during Care & Maintenance Preparations. The exterior of the reactor building will be modified to ensure that the building’s contents remains safe, secure and weatherproof throughout the Care and Maintenance period; this will include the removal of glass windows and panels from around the reactor building and replacing them with


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cladding similar to that found elsewhere on the building. In addition any penetrations in to the reactor building will be sealed and clad. A new gatehouse will be constructed to provide a new controlled entry into the area. The turbine hall, cooling water pumphouse, offices, workshops, stores and radioactive workshops will all be demolished; a plan showing the structures to be demolished is shown in Figure WYA/GEN/3. Uncontaminated demolition rubble generated on site will be used for the in-fill of deep basements. All roads and hardstandings (other than the road that runs around the reactor building and new radioactive waste storage building) will be removed. Temporary contractors’ compounds and plant/equipment and materials storage areas will also be created as may one or more temporary spoil grounds. Some modifications to site services to meet the project requirements will be necessary. The existing mains water supplies already in place will be sufficient for Care and Maintenance Preparations purposes. The existing foul drains / sewage treatment arrangement will continue to apply. Towards the end of Care and Maintenance Preparations the existing pipework associated with the foul drains will be left in situ. Intermediate level radioactive waste existing on site will be packaged and placed in a new storage building designed and built for this purpose. The location of this building is shown on Figure WYA/GEN/4. When they are no longer needed, the radioactive waste storage building, waste retrieval and processing facilities will be decommissioned and demolished. At the end of Care and Maintenance Preparations the only significant structures remaining on the site will be the modified reactor building and a new radioactive waste storage facility. The modified reactor building will remain on site until Final Site Clearance, but the radioactive waste storage facility will be demolished as soon as practicable after the packaged operational ILW has been removed from the store12. Non-Radioactive Wastes During the decommissioning works, inert building debris will arise. Wherever possible this material will be used to fill in below ground voids. There will also be large quantities of non-radioactive scrap metal, glass and asbestos. All of this material will be removed from the site and, if practicable, reused or recycled. If it is not possible to reuse or recycle this waste then it will be sent to landfill or licensed disposal sites by the appropriate licensed carrier. Radioactive Wastes Radioactive wastes can be classified according to how radioactive they are. Types of radioactive wastes include Low Level Wastes (LLW) and Intermediate Level Wastes (ILW). Both types of wastes have arisen at Wylfa since generation began and both will arise during decommissioning. Radioactive waste can also be classified according to its origin: the types relevant to the decommissioning of Wylfa are ‘decommissioning’ wastes and ‘operational’ wastes. Decommissioning wastes are created as a result of the dismantling of radioactive plant, equipment and structures. Operational wastes are created from more routine day to day operations: they have arisen since generation began and will continue to arise during decommissioning. Further information on operational wastes can be found in Part One, Section 4 of the 2008 ES. During Care and Maintenance Preparations all LLW be managed in line with the NDA’s published strategy for the management of solid LLW13 (published since the 2008 ES was issued). This strategy recognises that the use of the Low Level Waste Repository (LLWR) must be optimised through use of the principles of the waste hierarchy14, and that other appropriate recycling/ disposal routes should be used in preference to disposal at LLWR. The strategy also describes the management of a sub-category of LLW, called Very Low Level Waste (VLLW), which can now be disposed of in appropriately permitted landfill facilities.

12 There has been a change in strategy for the radioactive waste storage building, See Appendix 1, lines 3 and 4. 13 Nuclear Decommissioning Authority: UK Strategy for the Management of Solid Low Level Radioactive Waste from the Nuclear Industry, August 2010. 14 The Waste Hierarchy promotes an order of preference for waste management, and from high to low the order is: Reduce, Re-use, Re-cycle, Re-cover energy, Disposal.

Wylfa, as with other nuclear licensed sites, will follow the NDAs solid LLW strategy15. For example, Magnox has recently utilised routes for the recycling of LLW metals (in agreement with LLWR), and it is anticipated that such routes will be utilised for metal LLW wastes at Wylfa wherever possible. This approach will involve the segregation and processing of LLW using appropriate on-site facilities. Retrieved ILW will be placed directly into Ductile Cast Iron Containers (DCICs) 16, which will then be stored in a purpose-built radioactive waste storage building. There is no disposal route currently available for any ILW, including the operational ILW already present on site. It is Government policy that the UK will have a national disposal site (or repository) for, among other things, operational ILW from nuclear power station sites. The radioactive waste storage building will therefore house the packaged ILW until a repository becomes available. However, as it will take time to identify an acceptable site, draw up plans, obtain planning permission and construct the repository, the operational ILW generated at Wylfa is likely to remain on site for many years. The storage building will be designed, constructed and maintained to appropriate standards and will be regulated by the ONR. It should be noted that although Cumbria County Council voted in January 2013 to withdraw from the process to find a host community for repository, the Government has stated that there is no change to the current approach, and that it will now embark on a renewed drive to ensure that the case for hosting a repository is drawn to the attention of communities, and to encourage further local authorities to come forward over the coming years to join the process17. The Government remains committed to a repository for the long-term management of radioactive waste. Care and Maintenance Once all the preparations are complete, Wylfa will then move into Care and Maintenance. During this phase natural radioactive decay will allow the level of radioactivity inside the reactors to fall. It is proposed that this stage will last until 85 to 105 years after final shutdown. Photograph A3 shows an artist’s impression of the reactor building and radioactive waste storage building during Care and Maintenance. The final appearance of the radioactive storage building will be determined through a planning application under the Town and Country Planning Act 1990. Photograph A3: An artist’s impression of the reactor building and radioactive waste storage building during Care and Maintenance.

15 The approach to LLW management has been updated since the 2008 ES, See Appendix 1, line 5. 16 There has been a change in the strategy for packaging ILW since the 2008 ES See Appendix 1, line 6.

Wylfa Power Station

17 See https://www.gov.uk/government/news/energy-secretary-responds-to-cumbria-nuclear-waste-vote.



At some time during Care and Maintenance it is expected that a national waste repository will become available. At this time the packaged operational ILW will be removed from the radioactive waste storage building and transferred to the national disposal site. The store itself will be demolished as soon as practicable after the packaged operational ILW has been removed from the store. The only other work that may be required on site, other than routine monitoring and surveillance, during this phase will be the refurbishment or replacement of the cladding on the reactor building as necessary. Wylfa will continue to be a nuclear licensed site and will continue to be subject to regulatory control in accordance with legislation. Regular visits will be made to the site by trained and competent personnel to confirm the continuing security and safety of the site and to perform any necessary maintenance and monitoring work. The inspection regime has yet to be finalised but would include external inspection that will identify any damage to the reactor building and radioactive waste storage building fabric, such as loss of cladding. A second reclad of the reactor building may be required during the Care and Maintenance period, if the cladding material is found to be in need of repair. The layout of the site during Care and Maintenance is shown in Figure WYA/GEN/4. Final Site Clearance All remaining facilities and structures associated with the power station will now be cleared from the site. This will include the reactors, boilers and all radioactive and hazardous wastes. There will be a need to erect a number of temporary buildings on the site to facilitate this clearance work, all of which will be removed by the end of Final Site Clearance. One of the temporary facilities required will be a new waste management facility. The function of this facility will be to receive wastes arising from the reactor, boiler, primary circuit components and reactor building dismantling; to sort the wastes as required; to carry out any further size reduction of wastes and to load the wastes into boxes suitable for final disposal. Other facilities and work required during Final Site Clearance may include the following:

Upgrading/modification of installed security systems and site access control; Installation and/or upgrade of power, telecommunications, water, drainage and

sewage systems to the site to support the enlarged workforce and activities to be carried out during Final Site Clearance18;

18 Given the number of personnel likely to be on-site for eight years, it is assumed that a foul drains and sewage treatment system similar to that currently in place will be re-instated for this phase.

Refurbishment/extension of site roads and car parks; Construction of offices and welfare facilities; Construction of workshops, stores, laboratories etc.; and Construction of change facilities and controlled access points.

Once building demolition nears completion, the removal of site infrastructure (i.e. roads, car parks, hardstandings, fences, water mains etc.) will commence. Monitoring will be used to confirm that no radiological hazard exists on the site (as defined by the regulatory regime in force at that time), any contaminated land having been remediated. The intention is that the site is de-licensed under the Nuclear Installations Act (1965, as amended); the site will then be available for alternative use.

5.2. How Will the Work be Managed?

Detailed information on the management of the site and work during all phases of decommissioning can be found in Part One, Section 6 of the 2008 ES. A summary is provided below.

Hours of Work Typical normal working hours during decommissioning will involve staff working a 37 hour week, starting and finishing between the hours of 07:30 and 17:30, Monday to Friday. Working hours may alter for certain activities; for example, from time to time the working day may be extended in order to complete specific items of work safely, and some night-time working may be required to accommodate certain activities such as concrete pouring. Seven days a week, 24 hours a day shift working may be necessary for retrieval of operational ILW and for subsequent waste packaging operations but these operations will take place within buildings only.

Numbers of Workers The current power station workforce comprises 589 permanent staff, with around 100 subcontractors. Numbers of workers will fluctuate over the course of the decommissioning project but the maximum number of workers on site (including staff and contractors) will be about 600 during Care and Maintenance Preparations. However, the numbers of permanent staff at the site will drop during Care and Maintenance Preparations, from nearly 600 at the start to around 250 (by 2020, approximately halfway through this phase) and will continue to fall until the site enters Care and Maintenance. There is expected to be no permanent presence for the majority of Care and Maintenance (with the exception of routine maintenance and security personnel) and a maximum of 450 workers in Final Site Clearance. HGV Movements There is likely to be a temporary increase in the number of Heavy Goods Vehicle (HGV) movements to and from the site as a result of the proposed Care and Maintenance Preparations activities. Excluding the continued routine deliveries of consumables, peak HGV movements associated with this phase are estimated to reach no more than 35 vehicles travelling to and away from the site on a week day. The movement of HGVs over weekends is expected to be very limited. During Care and Maintenance there will be very little traffic travelling to and from Wylfa. The only regular traffic movements will relate to security or inspections personnel, with visits for maintenance purposes as and when required. The demolition of the radioactive waste storage facility will require some HGV movements over a short period, with peak HGV movements associated with this work are estimated to reach no more than 35 vehicles travelling to and away from the site on a week day. These vehicles will carry recyclable materials from the site (e.g. metals).


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HGVs movements associated with Wylfa during Final Site Clearance are estimated to reach an average of 50 vehicles travelling to and from the site on a week day. Once the Final Site Clearance phase is complete, there will be no traffic travelling to or from Wylfa power station. Land Use Almost all of the works will be carried out within the current outer site fence. The main exception to this is the work associated with the jetty, offshore seawater intake structures and cooling water (CW) outfall complex. Suitable notices to mariners will be issued via the Admiralty highlighting any navigational issues, including the loss of the navigation lights currently on the structures. Any vessels involved in offshore work will be marked and appropriately lit as agreed with the relevant bodies. The 2008 ES identified six potential laydown areas, including four outside of outer site fence (see Figure WYA/GEN/5). The four laydown areas that were outside of the outer site fence have since been had been transferred to Horizon (these areas were known as: Alternative Laydown Areas 1-3, and Laydown Area 3). The decommissioning team at Wylfa have reviewed the size of the remaining Laydown Areas (1 & 2) against those at other Magnox decommissioning sites and have concluded that these are sufficient for the purposes of decommissioning, and therefore no additional laydown areas are required. Radioactive Discharges During decommissioning, radioactive discharges to air and to the sea from Wylfa will continue. It is expected that gaseous and liquid discharges will be reduced compared with when the station was operational. However, there may be peaks resulting from certain activities. All discharges will be made in accordance with authorisations granted by the EA under the provisions of the Environmental Permitting Regulations 2010. A summarised description of the discharges expected to arise during decommissioning is given in Box A3. Where necessary, buildings and work areas with the potential for airborne radioactive contamination will have forced ventilation with exhaust air passing through filters as appropriate. The radioactive waste storage building will be ventilated by passive means - air in this building is expected to contain only traces of tritium (the radioactive form of hydrogen). Discharges, aerial or liquid, will be monitored and reported to the EA as required under the terms of the discharge authorisation.

Box A3: Radioactive Discharges Care and Maintenance Preparations The main sources of radioactive gaseous discharges will be from the reactor vessels which had

held the fuel in the reactors and from the ventilation of contaminated areas. Radioactive liquid effluent arisings will result from wet cutting operations, decontamination

operations, the use of showers and the operation of laundries. All waste water arising on site that has the potential to be radioactively contaminated will be treated to minimise its radioactive content before being discharged to the Irish Sea.

Care and Maintenance There will be a small gaseous discharge of radioactivity from the reactor vessels and there will also

be traces of tritium (the radioactive form of hydrogen) being released to the atmosphere from the radioactive waste storage building. Overall the atmospheric discharges from the site will be much smaller than when the reactors were operational, much lower than during Care and Maintenance Preparations and much lower than the current authorised limits.

Under normal circumstances no liquid radioactive discharges are expected. Final Site Clearance Radioactive airborne emissions will result mainly from cutting processes to dismantle the reactor. Radioactive liquid wastes will result from water drenching of cutting activities.

Further information on radioactive discharges from Wylfa can be found in Part One, Section 8 of the 2008 ES. Safety


As now, the safety of the public and the workforce will be a priority during decommissioning. Safety, both nuclear and conventional, will be regulated by the HSE in consultation with the EA. Wylfa will continue to be licensed under the Nuclear Installations Act (1965, amended) and therefore will still require a Safety Case, this being a document or set of documents that provides for the safe operation of plant and equipment or the carrying out of certain activities. As the decommissioning of Wylfa continues, the Safety Case will be updated progressively. Further information on the safety case system, as well as emergency arrangements, can be found in Part One, Section 8 of the 2008 ES. Security Security arrangements that comply with Government requirements are in force at Wylfa. These are kept under review by Magnox and its regulators to ensure their continuing effectiveness. As the detailed security arrangements at civil nuclear sites are a sensitive matter, in accordance with Government policy details are not included in this submission. Security at Wylfa will remain on shift 24 hours per day, seven days per week during Care and Maintenance Preparations and Final Site Clearance. For the Care and Maintenance phase all the buildings remaining on the Wylfa site will be designed to be resistant to unauthorised entry and will have intruder detection systems. Full time on-site security personnel may therefore not be required during this phase, subject to Civil Nuclear Security (CNS)19 approval.

Wylfa Power Station

19 Through the CNS Programme, ONR regulates the security of civil licensed nuclear sites.


6. CHANGE IN DECOMMISSIONING STRATEGY SINCE 2008

There has been no change to the overall strategy for decommissioning Wylfa since the original ES was produced in 2008. In terms of the approach to decommissioning, since 2008 Magnox has identified that the an alternative package design is the best approach for storing some forms of radioactive waste and has adopted the Magnox Optimised Decommissioning Programme (MODP) in order to coordinate a consistent programme of decommissioning across sites which prioritises high hazard reduction. However these changes do not affect the overall strategy that formed the basis of the original ES in 2008. A summary of changes is presented in Appendix 1 of this document. The proposed option for operational ILW that is to be retrieved and re-packaged during Care and Maintenance Preparations has changed since the 2008 ES was issued. The 2008 ES baseline was to retrieve this waste from its current storage location, then encapsulate and package in appropriate storage containers. Retrieved ILW will now be placed directly into Ductile Cast Iron Containers (DCICs) without encapsulation. This relates to approximately 50 cubic metres of ILW, which will require up to 20 DCICs. ILW currently stored in the reactor equipment building voids will be left to Final Site Clearance and there has been no change to this approach (this is the majority of ILW at the site, approximately 820 cubic metres). As mentioned in Section 5.1, there is now far more emphasis on the use of the waste hierarchy to manage LLW, in line with the NDAs published strategy. However as in the 2008 ES all LLW will be packaged and taken from the Site, but now there is greater emphasis on sorting and segregation of LLW, to allow best use of the waste hierarchy. As a consequence of the revised decommissioning start date, the timings of some of the individual components of the decommissioning project have changed. The timing of the major components of decommissioning was presented in the original 2008 ES (Table 6.1 of the 2008 ES). This table has been reproduced below (Table A 2), with the revised dates based on the expected date for Wylfa to cease electricity generation. Table A 2: Revised Decommissioning dates (originally derived from Table 6.1 of the 2008 ES).

ES 2008 ES 2008 REVISED REVISED

START FINISH START FINISH

DSC’s 1, 2 & 3 and Fuel Handling Areas Deplanting

2015 2019 2017 2021

DSC’s 4, 5 & Diverse Discharge Route (DDR) deplant, decommission & demolish

2018 2024 2017 2025

Turbine Hall and Associated Buildings deplant 2013 2018 2015 2020

Turbine Hall demolition 2016 2019 2018 2021

CW pumphouse deplant, demolition and in-fill; removal of jetty and sealing on inlet and outlet culverts.

2013 2017 2020 2024

Design & construction of the radioactive waste storage building (ILW store)

2015 2017 2015 2016

Wet LLW retrieval and processing 2012 2017 2021 2023

Desiccant retrieval and processing 2014 2018 2020 2020

Construct active waste management facility 2013 2016 2015 2018

Deplant active waste management facility 2022 2024 2023 2025

Reactor building safestore preparations 2013 2025 2016 2025


DSC ILW debris retrieval and processing 2014 2021 2013 2019

Security and boundary fence modifications 2017 2018 2018 2020

RCA decommission, demolition and remediation

2017 2019 2016 2018

Care & Maintenance Preparations final site buildings demolition and remediation

2021 2024 2021 2025

Most dates in the above table can be seen to be similar between the 2008 ES and the revised current plan. Those with a significant change, defined as greater than two year change in start date or duration (i.e. more than can be explained by the revised decommissioning start date alone) are explained below.

Cooling Water Pumphouse works – these have been moved in the plan as these have been identified as ‘non-critical path’ and have been shifted to avoid front loading the decommissioning programme, so that earlier works can concentrate on higher-hazard works.

Wet LLW retrieval and processing – dates revised to reflect that wet LLW is only found in

the sludge settling tanks that are part of the Active Effluent plant – this plant will be operational for most of the Care and Maintenance Preparations phase.

Desiccant retrieval - change of strategy to DCICs has meant that this work can be

completed in a shorter timescale then previously predicted. A trial to decay-store20 desiccant in a DCIC is already underway at Wylfa.

Reactor building safestore preparations – change in response to extended generation but also experience from similar works at other sites.

More detailed information on carrying out the decommissioning and waste management works can be found in Part One, Section 6 of the original 2008 ES. As mentioned above, it is now proposed to demolish the radioactive waste storage facility as soon as practicable after the packaged ILW has been removed to a disposal facility. The timing of this is assumed to be after 2040.

Wylfa Power Station

20 Decay-store – this approach allows the desiccant to decay to LLW, which can then be disposed of to the Low Level Waste Repository, or other appropriate routes.



7. THE ROLE OF THE ENVIRONMENTAL MANAGEMENT PLAN (EMP)

As described in Section 1 of this document, Wylfa currently has consent to decommission (though as described above this will expire before decommissioning can commence at Wylfa). A condition of the existing consent is that Wylfa produces an EMP21. The EMP describes the mitigation measures (from the 2008 ES) to prevent, reduce and where possible offset any significant adverse effects on the environment. The EMP therefore has a key role during decommissioning to ensure that mitigations listed in the 2008 ES, and from the outcome of this review, are enacted on the ground during specific projects. The EMP is therefore the mechanism by which Wylfa remains legally compliant with the consent to decommission. The EMP lists:

The mitigation measures that are already identified in the environmental statement; The options to implement work activities where mitigation measures may be required but

where selection of an option will only be possible in the future; and The work activities where mitigation may be required but where assessments to identify

mitigation measures will only be possible in the future. It is also a requirement of the conditions attached to the consent to describe in the EMP the effectiveness of the mitigation measures over time. The EMP is therefore a living document that is reviewed and revised throughout the course of the decommissioning project. The EMP is re-issued annually and submitted to the HSE / ONR (the EMP is also available to stakeholders and the public), and at other Magnox sites the ONR has audited performance against the EMP22. The EMP also includes details of any future survey requirements, where they are specified as part of the mitigation requirements in the 2008 ES. For example, in terms of some specific buildings at the site, bat surveys have been identified as being required two years prior to their demolition. In this case the buildings at Wylfa have already been surveyed for bats, but given the long-timescales of decommissioning (e.g. in comparison to a typical construction development) it is appropriate to utilise the statutory mechanism of the EMP to ensure that surveys are repeated at the most suitable time. In the specific case of bats, the known roost at the site is also monitored regularly, and any change in numbers or roost locations would be reported in the EMP. It is anticipated that any future decommissioning consent granted to Wylfa will include a condition to prepare and submit an EMP as described above. All future survey requirements (either identified in the 2008 ES or as part of this review) will be included in the re-issued EMP. Also, any potential future opportunities for co-operation to promote sustainable development, or manage cumulative impacts, with Horizon and other major infrastructure projects on Anglesey will be listed in the EMP (such as joint traffic management plans, or other joint mitigation). However as noted above there are no sufficiently well-developed infrastructure projects on the island that could allow us to make firm commitments at this stage (see Section 8 of this document). The EMP therefore provides a transparent view of all mitigation and survey requirements, as well as being a reporting tool to ensure openness in terms of the progress of decommissioning and the effectiveness of the associated mitigation measures to protect the environment.

21 Wylfa Site Environmental Management Plan Issue 3 June 2012 22 Site-specific ‘intervention reports’ are produced by the ONR after these audits, which can be found here: http://www.hse.gov.uk/nuclear/intervention-reports/index.htm

http://www.hse.gov.uk/nuclear/intervention-reports/index.htm

8. DEVELOPMENT PROJECTS IN THE WYLFA AREA

It is important that an EIA takes full account of any surrounding developments that could create cumulative environmental impacts, or which could impact upon the effectiveness of mitigation put in place to protect the environment. This is particularly relevant given the long timescales associated with decommissioning Wylfa, and was identified in the PAO response (See Section 1.3 above). Since the 2008 ES was prepared, a number of significant infrastructure projects have been identified as being potentially located on Anglesey. By far the most significant proposal for the area around Wylfa is the proposed construction of a new nuclear power station (see Section 8.1 of this document). Although the potential impacts of the development projects described below are, for the most part, not sufficiently mature to accurately assess at this stage, the legal mechanisms described above ensure that they will be assessed as more specific details become available. These legal mechanisms are in place to ensure that, during the course of decommissioning, any change to the consented project description or associated mitigation proposals is appropriately assessed. Any change, either as a result of external factors (e.g. surrounding developments) or internal factors (e.g. Magnox decommissioning strategy) must be assessed, and reported to the ONR as a condition of decommissioning consent23. Additionally, any change or extension to the decommissioning project (including any brought about as a result of a surrounding development) that may have significant adverse effects on the environment must be assessed under Regulation 13 of the Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations 1999 (as amended). Where adverse impacts are identified, the licensee is required by Regulation 13 to the seek a determination from the HSE / ONR as to whether the project shall be made subject to an EIA, and must not commence or continue with the project until such determination has been made. It should also be noted that all forthcoming major development will be subject to EIA regulations under the Town and country Planning Act, and any EIAs that arise from this will have to take into account Wylfa’ s decommissioning project as part of a cumulative impact assessment.

8.1. Nuclear New-Build

In 2009, the land surrounding Wylfa was nominated into the UK Government’s Strategic Siting Assessment process (SSA) as a site potentially suitable for the deployment of a new nuclear power station by the end of 2025. After being included in the Government's draft Nuclear National Policy Statement (NPS), the site was listed in the final NPS in June 2011 along with seven other sites deemed strategically suitable for nuclear development. The Nuclear NPS was approved by a vote in Parliament on 18th July 2011.

Horizon Nuclear Power is now proposing to construct a new nuclear power station in the area immediately adjacent to the Wylfa site. Transfer of land from Wylfa (and other surrounding properties) to Horizon has taken place.


In October 2012 Horizon’s shareholders – (E.ON UK and RWE npower) announced that agreement had been reached to sell Horizon to Hitachi. The sale of Horizon means that the details of the new nuclear power station will be different from those previously released by Horizon, because Hitachi are proposing to build Advanced Boiling Water Reactors (ABWR), which were not previously considered. Hitachi must achieve licence acceptance for the ABWR under the ONR’s Generic Design Assessment process. This means that immediate physical works at Wylfa are not likely to occur in the very near future, though this remains uncertain at this point, and Hitachi have indicated their desire to have an operational site in the UK (land at Oldbury in Gloucestershire is also owned by Horizon) by the first half of the 2020s.

23 It is assumed that any new consent would contain the same or similar condition.

Wylfa Power Station

It is likely (though again not certain) that the output from the proposed new nuclear power station would be connected to the National Grid via the existing 400kV substation (which is adjacent to the Wylfa site) however an extension to the existing sub-station may be required as well as additional transmission infrastructure (given the much higher power output that the new station will produce). It is understood by Magnox that an application for development consent and supporting ES will be brought forward by National Grid Electricity Transmission PLC, which will set out the full details of the required alterations, and associated their potential environmental impacts.

8.2. Other Infrastructure projects in Anglesey

A number of significant infrastructure projects on Anglesey are now proposed that had not been initiated at the time of the 2008 ES. No direct account of their impact on Wylfa’s decommissioning plans can be undertaken at this stage, because the relevant plans are not sufficiently mature, with one exception which is detailed below. However they could ultimately affect Wylfa’s decommissioning plans or mitigation (e.g. through the potential for cumulative environmental impacts). A major initiative in the area is the Anglesey Energy Island Programme (EIP), which is a collective effort between several stakeholders (including Wylfa) within the public and private sector working in partnership to enhance the local economy and put Anglesey at the forefront of energy research and development, production and servicing. Wylfa fully supports the EIP and close working will be maintained to ensure that relevant developments are taken into account during the decommissioning project. The proposed developments currently identified as part of this programme are as follows; it should be noted that none of these proposals have received formal planning permission at the time of writing:

A large offshore wind power development (Rhiannon Wind Farm) in the Irish Sea to the north of Anglesey, proposed by a joint venture collaboration of Centrica and Dong Energy (‘Celtic Array’);

A biomass-burning combined heat and power plant at the site of the former Anglesey Aluminium plant, proposed by Lateral Power; and

A marine tidal turbine array between Carmel Head and The Skerries, proposed by Marine Current Turbines.

Planning permission for a Liquid Natural Gas plant at Amlwch was approved in March 2008, and the planning application is expected to be renewed because the original permission will expire on 28/03/13. In 2008 an ES was submitted for this project and it is understood that an updated ES will be submitted to support a renewed application. This will be reviewed by Wylfa when it is available.

In addition to these potential developments there is a series of infrastructure and other supporting proposals that would act in conjunction with the above list:

An upgrade of the high-voltage power lines within and leading off Anglesey by National Grid, to support the large output of the proposed developments;

An accommodation development in Holyhead proposed by Land and Lakes for construction workers as part of the Horizon Nuclear Power project (to be reused as a holiday destination after completion the construction project);

An upgrade to the Port of Holyhead, being developed by Stena Line, with a view in part to take advantage of the Celtic Array development.

With the exception of the Marine Current Turbines development, for which an Environmental Statement has been produced, none of the major infrastructure projects are sufficiently mature for their impacts to be taken directly into account in this review – for example details of timings, worker numbers, planning drawings are not available.

8.3. Marine Current Turbines

An ES is available for review for the off-shore elements of this project. This comprises the following elements:


Up to 9 twin rotor “SeaGen devices” with an output of 1.0 – 2.0MW; Inter-array cabling; A single 33 kV subsea export cable; and Cable protection where necessary.

The proposed array of tidal energy devices will be located 850m (at its closest point) from the coast of Carmel Head and the associated landfall for the onshore works would be located either between Carmel Head and the western boundary of Hen Borth Bay or within Hen Borth Bay itself. The offshore works are likely to take place at least 2km from Wylfa. An ES has been submitted to the responsible regulatory authorities, which are the Welsh Assembly Government (WAG) and the Department for Energy & Climate Change (DECC). However, the ES for the Marine Current Turbines project is limited to the off-shore works, and no details of an on-shore grid connection (potentially to be at Wylfa) are as yet available. The off-shore works have been reviewed in detail under each of the EIA topic areas (see Section 12) however there is not considered to be any potential for cumulative effects between these works and the Wylfa decommissioning project.


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9. OVERVIEW OF UK GOVERNMENT AND MAGNOX DECOMMISSIONING AND WASTE MANAGEMENT STRATEGIES

This was discussed in full in Section 5 of the 2008 ES. The following updates are applicable because of their relevance to decommissioning:

Decommissioning and Low Level Waste – a new NDA strategy has been adopted (see Section 6 of this document);

Magnox has adopted the ‘Magnox Optimised Decommissioning Programme’ (MODP). Under the MODP the delivery of decommissioning is organised by a Strategic Programmes group that ensures that consistent solutions to decommissioning projects are delivered across all Magnox Sites(see Section 6 of this document);

Part of the MODP involved the introduction of DCICs (see Section 6 of this document); Magnox has produced generic Care and Maintenance entry specifications and

management arrangements24 (see below); and The NDA has undertaken a Site End State review (see Section 11 of this document).

The documents listed above do not change the overall decommissioning strategy at Wylfa. New routes for LLW will be utilised where these represent the best available technique for dealing with specific wastes (as opposed to being disposed of at the LLWR facility near Drigg in Cumbria. The impact of the MODP is discussed in Section 6 of this document. The Care and Maintenance entry specifications and management arrangements provides a greater level of detail on the configuration of the site at the start of this phase, and how arrangements for inspection and maintenance will be managed. This does not impact the decommissioning project described in the 2008 ES directly, with the potential exception of the in-filling of structures with large voids, which includes the turbine hall, and structures associated with the site’s cooling water system. The Care and Maintenance entry specification now includes an option not to completely in-fill large voids during Care and Maintenance Preparations where the quantity of suitable in-fill material on the site is not sufficient. This reflects experience of other Magnox sites during decommissioning, where levels of available in-fill material have not been sufficient to fill voids completely. The Magnox site Hinkley Point A has overcome this problem by using spoil from the adjacent nuclear new-build site (Hinkley Point C) to fill the void in its turbine hall – a potential synergy between new build and decommissioning that could be relevant to Wylfa. However, it is still proposed to in-fill all the voids at Wylfa, and any change to this strategy would be assessed on a case-by-case basis, with assessments made under Regulation 13 of the Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations 1999 (as amended).

24 Magnox: Care and Maintenance Entry Specification and Outline Management Arrangements. C&M-REP-001, Issue 01, December 2012.

10. THE LEGISLATIVE AND REGULATORY FRAMEWORK

In addition to the usual regulation of industrial and other sites by local authorities, the decommissioning of nuclear power stations in England and Wales is directly overseen by two other statutory regulators: ONR (including the Civil Nuclear Security Programme), and the EA. In broad terms the ONR is concerned with nuclear safety, security, and the environment through the EIADR99 process. The EA is concerned with environmental issues relating to discharges, waste and other matters. However, the roles are complementary and require both bodies to work together to deal with issues which have both safety and environmental implications. Therefore the decommissioning of Wylfa will be controlled under various regulations and consents in addition to the Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations 1999 (as amended). A number of these regulations and consents were described in more detail in the 2008 ES, as these were considered of particular relevance to decommissioning sites. These are shown in Table A 3 below, with updates as required for 2013. Table A 3: Legislative Regulations and Regimes Applicable to Decommissioning (originally derived from the 2008 ES Non-Technical Summary, Box 5).

From 2008 ES Description 2013 Update The Health and Safety at Work etc. Act 1974

This Act makes provision for securing the health, safety and welfare of persons at work.

No change; legislation is still current and enforceable.

The Control of Asbestos Regulations 2006

These require those in control of non-domestic premises to take certain measures to control the risks associated with asbestos.

Legislation superseded by The Control of Asbestos Regulations 2012

The Control of Noise at Work Regulations 2005

These place duties on employers to eliminate or reduce any risk in respect of exposure of workers to noise;


The Regulatory Reform (Fire Safety) Order 2005

This is the primary fire safety legislation; it provides a risk-based approach to fire safety and affects employers and those who are responsible for non-domestic, industrial premises.


The Building Regulations 2000

The regulations make provisions for buildings in terms of health, safety, welfare, convenience, conservation of fuel and power and prevention of contamination of water.

Legislation superseded by The Building Regulations 2010

Article 37 of the Euratom Treaty.

This requires the UK Government to make a submission to the EC about disposal or discharge of radioactive waste or effluent.


Nuclear Installations Act 1965 (As Amended).

This Act is the primary means by which all matters of nuclear safety on licensed sites such as Wylfa are regulated by a licence granted by the HSE.


Radiation (Emergency Preparedness and Public Information) Regulations 2001.

These require there to be an emergency plan for the purpose of restricting radiation exposure in the event of any reasonably foreseeable radiation emergencies, and also requires related emergency plans.


Radioactive Substances Act 1993.

This requires prior approval from the EA for the disposal of radioactive wastes, including the discharge of radioactive effluents to the

Legislation consolidated into and superseded in England and Wales by The Environmental Permitting Regulations 2010


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From 2008 ES Description 2013 Update environment.

Ionising Radiation Regulations 1999.

These specify controls on radiation exposure for members of the public and workers, as enforced by the Health and Safety Executive.


Environmental Protection Act 1990 and various waste management regulations that derive from it.

These place controls on the transport and disposal of non-radioactive wastes, as enforced by the environment agencies.


Environmental Protection Act 1990 Part IIA Contaminated Land: i) the Contaminated Land (Wales) Regulations 2006 and ii) the Radioactive Contaminated Land (Modification of Enactment) (Wales) Regulations 2006

Set out the legislative regime for dealing with the legacy of contaminated land.

i) Amended 2012 ii) Amended 2007

i) Water Resources Act 1991 and ii) the Groundwater Regulations 1998.

These require a permit from the EA for the discharge of non-radioactive effluents into the aquatic environment.

i) No change; legislation is still current and enforceable ii) Legislation superseded by the Groundwater Regulations 2009

i) The Radioactive Material (Road Transport) Act 1991 ii) Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2007.

This provides controls on the transport of packages containing radioactive and hazardous non-radioactive materials and wastes.

i) No change; legislation is still current and enforceable ii) Legislation superseded by the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2009.

Town and Country Planning Act 1990.

This requires planning permission to be obtained for development (other than permitted development).


The Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999.

These require, in some cases, the production of an environmental statement and consideration of all relevant environmental information prior to the granting of planning permission for certain types of development.

Legislation superseded by the Town and Country Planning (EIA) Regulations 2011

The Coast Protection Act 1949 (As Amended).

This requires consent for and places controls on off-shore work that may be detrimental to the safety of navigation or to the environment.


The Manual Handling Operations Regulations 1992 (As Amended).

This requires employers to protect employees from the risks of injury from the manual handling of loads at work.


The Work at Height Regulations 2005 (As Amended).

This specifies controls on work at height where there is a risk of a fall liable to cause personal injury.


The Control of Vibration at Work Regulations 2005.

This requires employers to protect employees from the risks arising from exposure to hand-arm vibration at work and whole body vibration.


The Environmental Protection Act 1990: i) The Environmental Permitting (England and Wales) Regulations 2007, ii) The Environmental Protection (Duty of Care) Regulations 1991 (As Amended), iii) The Hazardous Waste (Wales) Regulations 2005 and iv) The List of Wastes (Wales) Regulations 2005.

These, inter alia, place controls on the transport and disposal of non-radioactive wastes, as enforced by the environmental agencies.

i) Legislation consolidated into and superseded in England and Wales by The Environmental Permitting Regulations 2010 ii) Legislation consolidated into and superseded in England and Wales by the Waste (England and Wales) Regulations 2011


From 2008 ES Description 2013 Update Pollution Prevention and Control (England and Wales) Regulations 2006 (As Amended).

These introduced an integrated approach to controlling pollution from industrial sources but have now been revoked by the Environmental Permitting (England and Wales) Regulations 2007.

The Environmental Permitting Regulations 2007 have in turn been superseded by the Environmental Permitting Regulations 2010.

The Land Drainage Act 1991 This require prior approval from the internal drainage board of the local authority for any works which may cause an obstruction to or alter the flow of any ordinary watercourse.


The Conservation (Natural Habitats & Species) Regulations 1994

These transpose the requirements of European Directive 92/43/EC into UK law. In particular they require plans or projects which are likely to have a significant effect on European sites (alone or in combination with other plans or projects) to be subject to an appropriate assessment before a licence or consent can be granted.

Amended 2010 and 2012

The Waste Electrical and Electronic Equipment Regulations 2006

These aim to reduce the amount of this waste going to landfill and to increase the rate of recycling.

Amended 2010

Table A3 part 2: New Legislative Regulations and Regimes Applicable to Decommissioning – this is not intended to be an exhaustive review of new legislation since 2008, but covers areas of particular relevance to Wylfa’ s decommissioning project.

New Legislation Details / Description The Control of Asbestos Regulations 2012 These update the previous (2006) regulations to take

account of the European Commission’s view that the UK had not fully implemented the EU Directive (2009/148/EC) on exposure to asbestos. The changes are limited, and primarily relate to additional requirements for non-licensed work with asbestos .

The Environmental Permitting Regulations 2010

These regulations superseded the Environmental Permitting Regulations 2007, completing the streamlining and combining of the Pollution Prevention and Control (PPC) and Waste Management Licensing (WML) regimes to create a single environmental permit. These regulations implemented environmental permits and made them enforceable by the environment agencies.

The Waste Batteries and Accumulators Regulations 2009

Establishes a legal framework and schemes for collecting, treating and recycling portable, industrial and vehicle batteries.

Waste (England and Wales) Regulations 2011 and Amendment 2012

These regulations combine several previous sets of waste regulations in England and Wales, and place greater emphasis on the waste hierarchy. Aims to protect the environment and human health by setting out a waste management framework. Key definitions include the principles of the waste hierarchy.

Natural Resources Body for Wales (Functions) Order 2012

Establishes Natural Resources Wales as the new Environmental regulator for Wales from Apr 1st 2013.

Marine and Coastal Access Act 2009 Reformed the way the marine environment is regulated. It introduced a Marine Planning system, simplified the licensing regime, and created the specialist Marine Management Organisation. MMO only extends to England but it is implementing EU requirements, so an equivalent organisation should be expected in Wales.

Environmental Damage (Prevention and Remediation) Regulations (Wales) – Wales

Seeks to achieve the prevention and remedying of environmental damage – specifically, damage to habitats

Wylfa Power Station


New Legislation Details / Description (6th May 2009) and species protected by EC law, damage to species or

habitats on a site of special scientific interest for which the site has been notified, damage to water resources and land contamination which presents a threat to human health. It reinforces the “polluter pays” principle – making operators financially liable for threats of or actual damage.

the CRC Energy Efficiency Scheme Order 2010 (SI 2010/768) (as amended)

This Order makes provision for the implementation of a simplified energy efficiency scheme called the CRC Energy Efficiency Scheme (the CRC Scheme).

The Controlled Waste (England and Wales) Regulations 2012

These Regulations classify waste and determine the meaning of controlled waste.

It should be noted that changes in guidance, planning policy or related areas is dealt with in the individual topic areas (Sections 13 - 21). Furthermore from April 1st 2013 Natural Resources Wales (NRW) is the new Environmental regulator for Wales. NRW will incorporate CCW, EA Wales and the Forestry Commission for Wales into one organisation. To maintain the consistency of this document throughout, we retain the use of CCW and EA terminology throughout, though this means that that reference to any future engagement with CCW or EA will be mean consultation with NRW as of April 1st 2013.

11. ALTERNATIVES

Under EIADR an outline of the alternative decommissioning options that have been considered and the reasons for selecting the chosen options (taking into account the environmental effects) is part of the information to be included in an ES. The alternatives considered for decommissioning Wylfa are fully described in Section 7 of the 2008 ES, and these remain valid, with the addition of the updates presented below. ILW Containers

Alternative ILW packages, known as DCICs were identified in the 2008 ES as being a possible alternative to the proposed ‘Nirex’ boxes. DCICs have now been adopted by the site - see Sections 7.50 – 7.53 of the 2008 ES and Section 6 of this document.

Transport

Magnox has also considered the use of road, rail and water transport for the transport of wastes and materials associated with decommissioning. The basis of the environmental impact assessment is transport of wastes and materials by road only.

Should nuclear new-build (or any other project) in the area include a Marine Offshore Loading Facility (MOLF) then Magnox would review possibilities for the use of such a facility with the owner / operator of the MOLF.

Site End States

The end state for Wylfa is to de-licence the site in order to make it available for alternative use. The NDA has reviewed the declared End States for all the sites for which it is responsible, including Wylfa25. The NDA asked Site Stakeholder Groups to consult their local communities on their preferred end state and end use for the sites. The Site Licence Companies were also asked to assess the feasibility of, and any consequences arising from, achieving the communities’ preferred option. For Wylfa, this consultation revealed that the local Stakeholders’ preferred end use is future power generation (including nuclear new-build). If this should not materialise they felt that the Wylfa site should be used for recreation as a nature reserve. These options are consistent with the proposed end state for Wylfa, and therefore there are considered to be no realistic alternatives to de-licensing followed by alternative use.


Wylfa Power Station

25 The 2008 ES referred to this review as being in preparation. It has now been completed: Nuclear Decommissioning Authority, Site Restoration. Output from Stakeholder Consultation for the Site End State: Wylfa. Issue 01, October 2009, SMS/TS/A2/1/1/R018.


12. THE ENVIRONMENTAL IMPACT ASSESSMENT

The EIA process identifies the potentially significant environmental effects and the impacts of these (positive or negative) associated with a project, and allows them to be taken into account in the decision making process. The impacts associated with the decommissioning of Wylfa were considered under specialist topic areas (the same in both the 2008 ES and the 2013 Update). The approach to this Section has been to extract the relevant summary information from each topic area from the 2008 ES and to highlight any changes since that assessment was made. For each topic area the assessment of change is based on an independent review of the 2008 ES by Hyder26. Further information on each of the topics below is available in Part 2 of the 2008 ES. In order for the assessment to be easier to follow each of the specialist topics assessed the impacts in broadly the same way using a number of stages:

firstly, the magnitude of impacts (both adverse and beneficial) were considered, for

which the terms ‘Major’, ‘Moderate’, ‘Slight’ and ‘Negligible’ have been used throughout (and with a capitalised first letter to indicate use in assessing impacts);

next, the sensitivity of the receiving environment or receptor for the impact was identified; and

finally, the significance of the impact was assessed, again using common terminology, in this case ‘not significant’, ‘significant’ and ‘key significant’.

Where significant or key significant adverse impacts have been identified, mitigation is proposed. The mitigation measures propose to prevent, reduce or off-set these significant and key significant impacts are summarised in Appendix 4.

For no technical topic is it considered there is likely to be a significant impact on the environment in another European Economic Area (EEA) state.

26 Hyder Consulting 2013: Magnox Limited Wylfa EIADR: Review of 2008 ES for Wylfa decommissioning. Report number: 0001-UA005369-UU81R-01-WylfaEIADR.

13. AIR QUALITY AND DUST

The matters considered under Air Quality and Dust were: emissions of gaseous pollutants and particulates from vehicles; the raising and dispersion of dust from the site directly due to the site works; and the dispersion of dust from soiled vehicles or vehicles carrying potentially dusty loads off site.

13.1. Overview of the 2008 Assessment

How Significance was Determined in the 2008 ES

Emissions from vehicles were assessed by reference to national air quality objectives (AQOs); these exist for a range of pollutants including carbon monoxide (CO), nitrogen dioxide (NO2), benzene (C6H6), 1,3-butadiene (C4H6) and particulate matter less than 10 micrometres (μm) in diameter (PM10). If the objectives are met then current understanding is that there is no significant health risk. In respect of changes in air quality due to emissions from vehicles, an impact will be considered as ‘not significant’ if there is no change in compliance with AQOs; ‘significant’ if there is a change in compliance with one or more short term (daily periods or shorter), but no change in compliance with long term (annual average) AQOs; and ‘key significant’ if there is a change in compliance with one or more long term AQOs. For dust, significance has been determined largely on the basis of likelihood of complaint (dust nuisance), receptor sensitivity, residential properties being considered as high sensitivity, and whether commercial interests would be affected. Project Impacts and Mitigation Measures Identified in the 2008 ES

The traffic data that was used took into account predictions of future changes in background traffic in the Wylfa area. The assessment also took into account the ‘background’ air quality near Wylfa and, more generally, across the UK and how it is expected to change in the future. Pollutant levels due to vehicle emissions were estimated using the methodology set out in Department of Transport/Highways Agency’s Design Manual for Roads and Bridges (DMRB), an industry standard for this type of assessment. Using these methods, it is predicted that at no time and for no pollutant will any national AQO be exceeded as a result of the traffic associated with the decommissioning of Wylfa, and consequently the impact was classed as not significant. For the closest residential receptors the adverse impacts associated with fugitive dust in the absence of mitigation were assessed as not significant for dust directly from site and significant for dust from vehicles, these determinations being applicable to both Care and Maintenance Preparations and Final Site Clearance. Therefore mitigation measures are proposed in respect of dust from off-site vehicles, as set out in Appendix 4. With mitigation measures in place it is considered that dust impacts from vehicles would be not significant for both Care and Maintenance Preparations and Final Site Clearance. With regards dust from on-site activities, in terms of best practice the Building Research Establishment Code of Practice for the control of dust from construction and demolition sites will be followed. During Care and Maintenance there are unlikely to be activities on site and or vehicular movements with potential to cause significant air pollution or raise dust. Following Final Site Clearance, there will be no vehicle emissions and no potential for dust associated with the site. Further information on air quality and dust can be found in Part Two, Section 10 of the original 2008 ES.

13.2. The Outcome of the 2013 Update

New / revised environmental data

Since the production of the ES, more recent baseline data are now available. For example, the 2008 ES contains baseline information from the IoACC’s Review and Assessment reports, which


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are undertaken annually. The most recent review and assessment report referred to in the 2008 ES is from 2006/2007. In addition, more recent air quality monitoring data is now available, and the projected Department for the Environment, Food and Rural Affairs’ (Defra) background concentrations referred to in Table 10.10 of the 2008 ES have been updated. These updates have been included in the Hyder report27.

On-going Validity of the methods used in the 2008 ES

Since the production of the 2008 ES, there have been updates to air quality assessment criteria. Whilst the criteria are unlikely to change the impacts significantly, IoACC Environmental Health Officer (EHO) has requested that the criteria for determining the significance of vehicle emissions are updated in line with the latest guidance issued by Environmental Protection UK (EPUK), “Development Control: Planning for Air Quality (2010 update)” (EPUK, 2010). Based on the guidance, an air quality assessment is required if a construction site would generate over 200 HGV movements per day over a period of a year or more.

The 2008 ES indicates that the number of HGVs associated with the decommissioning would be well below 200 HGV per day. It is therefore considered unlikely that the HGV flows as a result of the decommissioning would have a significant impact on air quality.

New cumulative impacts

Provided that other developments (such as the proposed new nuclear power station at Wylfa) adopt suitable best practice mitigation measures, such as those outlined in the 2008 ES, the potential cumulative impact from fugitive dust emissions during the decommissioning phase should remain as predicted within the 2008 ES.

Traffic generated by other developments would cause increases in exhaust related pollutants in the vicinity of Wylfa. However, it is not anticipated that this would cause significant cumulative effects due to the low baseline concentrations in the area.

In terms of dust monitoring, an appropriate collaborative approach will be pursued with Horizon (in consultation with IoACC’s EHO) during the construction of the proposed new nuclear power station at Wylfa. It is not possible at this time to state that Horizon will adopt this approach, and therefore should this prove to be not possible then Wylfa will, following consultation with IoACC’s EHO, adopt an alternative approach. The use of directional dust monitors, such as Fablon sticky pads and Osiris monitors (with a meteorological mast) will enable dust sources to be identified (from decommissioning, or from the construction of the proposed new nuclear power station at Wylfa) and therefore enable appropriate precautions to be put in place.

New or revised impacts that were not assessed in the 2008 ES

Baseline air quality concentrations indicate that existing concentrations are low, and well below the relevant AQS Objectives, and review of the transport assessment indicates very little change in existing traffic flows to those reported in the 2008 ES. It is therefore considered that the impacts associated with the decommissioning are the same as those predicted in the 2008 ES (i.e. not significant).

The HGV flows associated with the decommissioning are well below the EPUK criteria of 200 HGV per day. It is therefore unlikely that the HGV flows as a result of the decommissioning would have a significant impact on air quality.

Using the predicted impacts in the 2008 ES, and the updated significance criteria presented above, the subsequent impacts as a result of vehicle emissions associated with the decommissioning are classed as Negligible at all assessed receptors.

Two of the receptors included within the assessment have now been demolished (Pen Lon and Simdda Wen). Therefore impacts predicted at these locations are no longer applicable.

On-going Validity of proposed mitigation in the 2008 ES

The mitigation measures outlined in the 2008 ES are considered to remain valid, and as such, no updates are considered necessary. However, following consultation with IoACC’s EHO, more prescriptive measures are required in terms of monitoring, which are discussed below.


Dust monitoring will be undertaken during any decommissioning activities that could create dust (e.g. construction and demolition) to ensure that the mitigation measures to control dust emissions are being applied and are working effectively, and the monitoring methods and locations will be discussed and agreed with the EHO well in advance of the works and initial discussions with the EHO will commence in advance of decommissioning. During the agreed monitoring period, visual monitoring will be undertaken in the vicinity of the site boundary at least once per working day and the results of the inspection recorded in a site log.

The use of automatic monitors (for example, installed at the site boundary) will be discussed with the EHO in advance of decommissioning. Such automatic systems include Osiris monitors, that can monitor a range of particle sizes simultaneously and continuously, and can be installed with a meteorological mast in order to determine the direction from which the dust is coming from. In addition, an alarm system can be activated, which is triggered when the dust levels reach a certain concentration.

In addition to the automatic monitors, passive monitors could be used to supplement the automatic monitoring. For example, Frisbee dust gauges can be used to measure deposited dust. Frisbee dust gauges do not have a directional component, therefore it is not possible to establish the direction of the dust. Fablon sticky pad monitors could therefore be installed alongside the Frisbee dust gauges in order to provide information on the likely contributions of dust emissions from different dust sources.

A period of baseline monitoring, using both automatic and passive sampling, would be required in order to determine baseline dust levels and to prescribe suitable trigger thresholds. To supplement the baseline monitoring data, IoACC has undertaken a period of long term dust monitoring close to Wylfa (namely around Tregele Village) to determine the baseline dust levels, thus providing a benchmark against which deposited dust levels during the decommissioning phase could be compared to.

Whilst the impacts as a result of vehicle emissions have been assessed as not significant, it may be prudent to implement a travel plan for significant construction / demolition activities, which would ensure the most economical use of construction vehicles, thus keeping the number of construction vehicles to a minimum.

13.3. Conclusions

The approach and mitigation measures identified in the 2008 ES are considered to remain valid. Following consultation with IoACC’s EHO, more prescriptive measures for monitoring Air Quality and Dust have been identified.


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14. ARCHAEOLOGY AND CULTURAL HERITAGE


None of the archaeological or historical features identified in the 2008 ES as being in the locality of Wylfa will be physically affected by the proposed decommissioning project. There is no evidence of any surviving features of archaeological interest within the licensed power station site that will be physically affected by the decommissioning project. The initial construction of the power station, particularly the deep foundations and basements of the turbine hall and reactor building, would have already affected (and probably destroyed) any below ground remains. The potential for any further remains on the site is negligible. However certain features of the historic landscape have the potential to have survived the disturbance of construction within the immediate vicinity of the power station, in the area of car-parking and overflow car-parking between Porth y Pistyll and Porth y Gwartheg and in the vicinity of the outflow at Porth Wnal. A walkover survey to identify any surface evidence of previous occupation and land use, including agricultural, industrial, maritime and wartime operations, will be undertaken prior to commencing any decommissioning works within these stated areas. Further information on archaeology and cultural heritage can be found in Part Two, Section 11 of the original 2008 ES.



Further to consultation with the Senior Planning Archaeologist for Gwynedd Archaeological Trust on the 17 January 2013, it has been agreed that the text submitted for the 2008 ES be re-structured in a manner that befits current recognised industry best practice.


Several of the documents in Section 11.5 of the 2008 ES are out of date. Updated references are listed below. Conservation Principles has been published since 2008 and is added to the list below. All other references remain the same.

The Code of Conduct and Standards and Guidance for Archaeological Desk-based Assessments of the Institute for Archaeologists (IfA 2012a; IfA 2012b);

Planning Policy Wales, Edition 4 (2011); Technical Advice Note (Wales) (TAN) 12 Design, 2009; and Conservation Principles, Cadw 2011 (Cadw is the Welsh Government’s historic

environment service).

The study area was agreed during consultation carried out Gwynedd Archaeological Planning Service during this update on the 16 January 2013. The Royal Commission on the Ancient and Historical Monuments of Wales was also consulted.


The adverse cumulative impact of the proposed new nuclear power station at Wylfa would balance out the beneficial impacts of decommissioning of Wylfa upon the Listed Buildings and Historic Landscape, leading to a neutral impact upon these cultural heritage assets. However, during the proposed construction period for the proposed new nuclear power station at Wylfa, there would be a cumulative Slight Adverse significance of effect upon the setting of these assets. However, this effect is not considered to be significant.

There would be no cumulative impact upon the below ground archaeological remains, as the proposed decommissioning works are not effecting this resource.


New or revised impacts that were not assessed in the 2008 ES Designated Assets The proposed decommissioning works would not physically impact any designated assets. Cestyll Gardens is the closest designated asset approximately 0.5km south west of Wylfa. The proposed works are outside of its essential setting area so they would have little impact on the setting of this asset. During the Care and Maintenance part of the process there would potentially be a Minor Adverse magnitude of impact which would result in a Slight Adverse significance. However when the decommissioning is complete and all buildings are removed there would be Slight Beneficial impact. Archaeology The construction of Wylfa, with its deep excavations, is likely to have removed all traces of structural evidence for past use for the headland within the footprint Wylfa. It is not anticipated that any further ground-intrusive works resulting in the disturbance of the burial environment of the Wylfa footprint is to take place. There would therefore be No Change on the buried archaeological resource. Certain above ground archaeological assets, such the sites of the military installations, have the potential to have survived the disturbance of construction within the immediate vicinity of Wylfa, particularly the car parking areas. As it is likely that the majority of such remains would have been removed by the works associated with Wylfa, the decommissioning works would have no more than a Minor Adverse impact on these potential assets. The complete removal of Wylfa would cause a Major Adverse impact upon this industrial archaeological asset resulting in a significant adverse effect. Historic Landscape The significance of the landscape of Wylfa headland is related to the fact that is has changed very little in recent times, apart from the addition of Wylfa. During the Care and Maintenance part of the process there would potentially be a Minor Adverse impact on the setting of historic landscape. This effect would be long term but not permanent and is not considered to be significant. The removal of Wylfa would reform the landscape to its former self, therefore having a Moderate Beneficial impact upon the landscape; this effect would be permanent. Therefore there would a non-significant adverse long term effect upon the historic landscape followed by a significant beneficial permanent effect.


Archaeology

In view of the industrial significance of the Wylfa complex, the Site and its structures will be recorded at an appropriate level before dismantling works are undertaken and records relating to its construction and use will be deposited in an appropriate archive.

It has been agreed with the Royal Commission on the Ancient and Historical Monuments of Wales that a photographic record prior to and during decommissioning works, supplemented by background information on the history of Wylfa, would constitute an appropriate level of recording.

A walkover survey would be carried out prior to the start of the decommissioning work to establish whether the military installations identified during the desk-top study have survived. The walk-over survey could be carried out in conjunction with the photographic survey and any remains recorded in the same way.

A Written Scheme of Investigation (WSI) providing detail of the necessary mitigation would be produced and agreed with Gwynedd Archaeological Trust prior to the start of decommissioning. This document would contain as a minimum the following information:

Consultation with a recognised expert;


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History of Wylfa; Any publicity, plans and photographs that already exist of Wylfa; Detail of the walkover survey of the site to identify any surface evidence of previous

wartime operations;

Detail of how Wylfa will be recorded prior to the start of decommissioning works and throughout decommissioning; and

Detail of how and where the archive will be deposited.

The construction of Wylfa would have removed any archaeological deposits within the proposed decommissioning area. Mitigation measures for any significant archaeological features or deposits (including buried land surfaces) that might be present in the burial environment of the site are not, therefore, required.

Built Heritage

It is not considered that any mitigation measures are necessary for the built heritage assets within the study area, as the proposed works would not have a significant adverse impact upon their setting and would have no physical impacts on them.

Historic Landscape

The impacts of the Care and Maintenance phase of the proposed works on the historic landscape are considered not significant therefore no mitigation is considered necessary.

14.3. Conclusions

The construction of Wylfa, with its deep excavations, is likely to have removed all traces of structural evidence for past use for the headland within the footprint Wylfa. It is not anticipated that any further ground-intrusive works resulting in the disturbance of the burial environment of the Wylfa footprint is to take place. There would therefore be No Change on the buried archaeological resource.

In view of the industrial significance of the Wylfa complex, it will be recorded at an appropriate level before dismantling works are undertaken and records relating to its construction and use will be deposited in an appropriate archive.


15. ECOLOGY

The matters considered under this topic were:

Habitat loss including the removal of on-site structures potentially used by bats and/or protected bird species;

The effects of the removal of off-shore structures on birds and marine flora and fauna, including habitat loss and disturbance due to the work;

The effects of noise, vibration and visual disturbance on fauna, particularly on birds using the foreshore;

Potential changes in incidental mortality of birds, amphibians, reptiles and/or other protected species as a result of site works or of changes in vehicle movements;

Possible effects of dust on sensitive habitats;

Potential effects of accidental spills or pollution on nearby water bodies and watercourses where there is a pollutant pathway from the site; and

Potential effects, similar to those listed above, upon sites designated for their nature conservation importance that are remote from the site.

The effects of the permanent loss of warm water discharges on marine flora and fauna (though strictly an effect of end of generation rather than of decommissioning as such) were also included in the assessment.



For this topic, the significance of an impact was determined in part on the nature conservation value of the ecological receptors (populations or habitats) affected. Nature conservation value is largely derived from a consideration of the degree of legal protection extended to a receptor or the weight attributed to the receptor in Central or Local Government policy (for example the UKBAP or LBAP). Population size and species or habitat rarity in a local or national context are also factors. Project Impacts and Mitigation Measures Identified in the 2008 ES

For the period of Care and Maintenance Preparations, in the absence of mitigation, the following significant adverse impacts were identified:

Disturbance to or loss of small amounts of coastal cliff grassland and strandline vegetation by use of Laydown Areas 1 and 2;

Loss of, or disturbance to habitat of moderate botanical interest in Laydown Area 2;

Disruption of the adjacent cliff habitat complexes by fragmentation of the coastal wildlife corridor due to extension of laydown area onto the cliff;

Potential degradation of species-rich vegetation on the AONB and Heritage Coast and in the Tre’r Gof SSSI caused by deposition of dust generated from demolition activities on site;

Accidental killing of adders during demolition of the towns water tank;

Disturbance to bird species from construction of a coffer dam, demolition of the Outfall Gatehouse complex and explosive demolition of the offshore Cooling Water jetty and offshore seawater intake structures;

Loss of habitat and increased disturbance could cause severe disruption to the gull colony in Laydown Area 1;


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Potential loss of habitat and or buildings could impact breeding birds, including loss of nests, eggs and dependent young;

The loss of Building 99 which supports a roost of common pipistrelle bats and the loss of other buildings with moderate or high potential to support roosting bats and subsequent loss of potential and actual roost sites;

Disturbance to foraging bats from light spill;

Disturbance to cetaceans and grey seals from explosive demolition (if this is the preferred method) of the Cooling Water jetty and offshore seawater intake structures.

No key significant adverse impacts were identified by the ecological assessment. The proposed mitigation against disturbance to or loss of coastal grassland in Laydown Area 2 is to use a buffer strip. The buffer strip will be marked off (by fence or hedge) from working areas to prevent incursion by personnel and vehicles and site measures to prevent spillages of materials into the coastal strip will be implemented. Personnel will be instructed on protection of the coastal strip. With this mitigation in place the impact on the coastal strip will be Slight Adverse and not significant. To prevent loss or disturbance to the coastal wildlife corridor adjacent to Laydown Area 1 it is proposed that no part of Laydown Area 1 is to extend beyond the outer security fence. With this mitigation in place the impact on the coastal wildlife corridor will be Slight Adverse and not significant. Dust can have adverse physiological effects on plants, e.g. reduction of gas-exchange or light penetration at the leaf surface (both affecting photosynthesis) and at the ecological scale it is therefore theoretically possible that plant communities might be altered because of differential effects on different species. In the worst-case scenario, there could be some degradation of species-rich vegetation on the AONB and Heritage Coast and in the Tre’r Gof SSSI. Dust generation in the concrete crusher and elsewhere will be controlled by the use of dust suppression techniques, as detailed in Part Two, Section 10 (Air Quality and Dust) of the original 2008 ES. With this mitigation, impacts on the AONB, Heritage Coast and the SSSI will be Negligible and not significant. The loss of habitat and increased disturbance to the gull colony in Laydown Area 1 will be mitigated by Laydown Area 1 being limited to the areas inside the outer security fence, thereby minimizing the amount of habitat which would be lost. This would limit the impacts on the breeding colony to an increase in noise and visual disturbance during the use of this area for laydown activities. The gull colony is however habituated to disturbance associated with normal power station operations and therefore the impact would be Slight and not significant. Potential loss of habitat and or buildings used by birds will be mitigated by ensuring that clearance of habitat and demolition of buildings used by birds is undertaken outside of the bird breeding season. With this in place, the impact of direct loss of habitats upon breeding birds would be Negligible and not significant. Impacts on adders during demolition of the towns water tank will be mitigated by placing reptile-proof fencing around the decommissioning works area and removing reptiles from within by hand searching or the use of refugia. Hand strimming will also be used to discourage adders from using the area prior to demolition. Following removal of the towns water tank, habitat suitable for adders will be reinstated. With this mitigation in place impacts on adders will be not significant. Any demolition of buildings harbouring bats, such as Building 99, will of necessity take place under a European Protected Species Licence (EPSL). Such licences always require a comprehensive mitigation plan based on up to date survey results. Therefore at least two years prior to demolition further surveys will be carried out on the bat roost in Building 99 to determine the species using the roost and their flight paths and foraging areas. Under appropriate licence Magnox will ensure the safe exclusion of bats from Building 99 prior to its demolition and will provide alternative roosting sites for the affected bats, together with any other mitigation that CCW deems necessary to ensure the favourable conservation status of the affected bats. With this mitigation there will be a Negligible and not significant impact on bats roosting in Building 99. In addition, a programme of internal inspection and survey work will be carried out on those buildings with ‘moderate’ or ‘high’


potential to support roosting bats. This work will begin at an appropriate time (in the order of two years) prior to their demolition. Mitigation for buildings with bat roosts will include licensed works for the safe exclusion of bats and provision of alternative roost sites. In buildings where surveys do not find roosts a ‘watching brief’ will be maintained during demolition, supervised by a suitably qualified and experienced ecologist. All staff involved in such work will be made aware of the potential for ‘high’ and ‘moderate’ buildings to house bats and if bats are found then work will stop immediately and CCW will be informed. With this mitigation in place the impact on bats will be Negligible and not significant. During winter months there may be light spill from working areas into areas used by bats for foraging. However, normal working hours will be between 07.30 to 17.30 and light spill will be minimised by the use of directional lighting. Light spill is therefore unlikely to affect bats during the spring, summer and autumn months when they are active. At most there will be a Negligible impact on foraging bats which will be not significant. With regards to disturbance to birds, in particular terns and the gull colony adjacent to Laydown Area 1, from the construction of a coffer dam at the Outfall Gatehouse location and demolition of the Cooling Water Outlet Culverts, Outfall Gatehouse and offshore structures, mitigation will involve ensuring that works are conducted outside of the breeding bird season (March to September). With this mitigation in place the impact is assessed as Slight to Moderate in magnitude and not significant. The use of explosives could cause severe but brief disturbance to marine mammals. Potential impacts will be minimized by carrying out explosions at low tide and visual checks for marine mammals offshore will be carried out by a dedicated observer standing onshore at a suitable vantage point near the jetty at least 1 hour before any planned explosion. If a marine mammal is spotted within 2km of the jetty then it will be tracked until it is out of range and the use of explosives will not commence until at least 30 minutes after the last detection of a marine mammal. With this mitigation there will be a Negligible impact on marine mammals and this is assessed as being not significant. During the Care and Maintenance phase the site will be maintained in a mainly quiescent state and there will be little potential for adverse ecological impacts. No significant adverse impacts have been identified at this stage. There may be a beneficial impact owing to likely colonization of the site by valued ecological receptors. Prior to Final Site Clearance, further surveys would be undertaken to confirm the presence or absence of species of conservation concern, which may result in a requirement for new or amended mitigation measures. Buildings will be inspected for their suitability for bats and an appropriate level of breeding bird surveys will also be undertaken, including a peregrine survey. No adverse impacts are identified for the time following Final Site Clearance, but the cleared site could instead represent a net gain in nature conservation, depending on the site’s end state. However, given the extensive time frame of many decades, there must be considerable uncertainty about future perspectives and imperatives on land use and nature conservation issues; therefore specific site enhancement measures (e.g. artificial establishment of vegetation) have not yet been considered. Further information on ecology can be found in Part Two, Section 12 of the original 2008 ES.



Primary ecological data is generally considered to remain valid for a period of up to two to three years after the time when a survey is undertaken. As such, the baseline data included in the 2008 Environmental Statement (2008 ES) has been reviewed and updated (where possible) following a site walkover survey on 10th January 2013 and an updated desk study. A summary of the findings


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of this review is presented below, with additional supporting information provided in the Hyder report28.

The findings of the 2007 Phase 1 habitat survey were found to still be valid since the habitats present on site were found to have changed little since the time of this original survey. As such, it is not considered necessary to repeat/update the Phase 1 habitat survey or the Phase 2 botanical survey (National Vegetation Classification (NVC)). Any small-scale changes to habitats and plants that may have occurred since 2007 would not result in any material changes to the impact assessment outlined in the 2008 ES.

The 2013 site walkover survey and the updated desk study found no evidence to suggest that the baseline conditions for great crested newts (Triturus cristatus), badgers (Meles meles), dormice (Muscardinus avellanarius), otters (Lutra lutra), water voles (Arvicola amphibious) and other terrestrial mammals (with exception to bats) would have changed significantly since the time of the original baseline surveys in 2007. These species had been scoped out of the detailed (2008 ES) impact assessment on the basis that no evidence was found to suggest their presence within an area whereby they could be affected by the proposed works. This was consistent with the results of the 2013 site walkover survey, and no records (since 2007) of these species were identified within 2km of the site boundary during the updated desk study. The baseline conditions outlined in the 2008 ES for these species are therefore considered to remain valid.

The baseline conditions outlined in the 2008 ES identified that a bat roost was found to be present within a building on site (Building 99). An updated bat survey of this building was undertaken in September 2012 to confirm the status of this roost at that time29. This survey found that actively roosting bats were still present within this building, and so it is considered likely that the baseline conditions as outlined in the 2008 ES for this bat roost remain valid. As bats are mobile, it is an additional bat survey will be undertaken to update the baseline conditions for roosting bats elsewhere within the site. This will focus on buildings that were identified in 2007 as having moderate to high potential for supporting roosting bats. This will also be necessary to inform any required licence application, or Method Statement prior to demolition works commencing.

The baseline conditions in the 2008 ES identified a small population of adders (Vipera berus) within the Wylfa Nature Trail area, with reptiles being found to be absent from the land within the site boundary. The 2013 site walkover survey and desk study did not identify any evidence that would suggest that these conditions are likely to have changed significantly since the time of the 2007 baseline surveys. It is possible, due to the presence of suitable habitat within the site boundary, that widespread reptile species, including adder and viviparous lizard (Lacerta viviparia), could have colonised this area since 2007. However, such an eventuality would not materially alter the outcomes of the 2008 ES, since any reptiles that could be present there would not represent a medium to large population, and therefore any effect on them would not be significant. The potential presence of reptiles within the site boundary can be dealt with through precautionary mitigation to ensure legislative compliance during the decommissioning works.

Following the 2013 site walkover survey and updated desk study, it is considered likely that the baseline conditions for birds could have changed since the time of the 2007 surveys. The 2008 baseline conditions for birds that are included as qualifying features of the Ynys Feurig, Cemlyn Bay and The Skerries Special Protection Area (SPA) showed that such species had not bred within an area whereby they could be significantly impacted by the proposed works, although some foraging activity was recorded offshore in close proximity to the site. Given the time that has lapsed since the baseline surveys, the baseline conditions for breeding SPA species will be updated by additional targeted surveys between the months of May and July. These will be required to demonstrate that the SPA will not be significantly affected as in accordance with the Conservation of Habitats and Species (Amendment) Regulations 2010.

It has been confirmed that a pair of choughs (Pyrrhocorax pyrrhocorax) (a specially protected species that is listed on Schedule 1 of the Wildlife and Countryside Act 1981 (as amended)) have since bred within a dry-cell building on the site. This species was scoped out of the detailed 2008 ES impact assessment on the basis that it had not been recorded breeding on site prior to then. It

28 Hyder Consulting 2013: Magnox Limited Wylfa EIADR: Review of 2008 ES for Wylfa decommissioning. Report number: 0001-UA005369-UU81R-01-WylfaEIADR. 29 Magnox 2013: Engineering Advice Note: Bat Survey of Building 99 at Wylfa. M/EF/WYA/EAN/0005/13.

is therefore necessary to update the baseline conditions for this species and include it within the updated impact assessment (see below).

Although the baseline conditions for other notable bird species is likely to have changed slightly since the time of the 2007 surveys, it is unlikely that any such changes would result in a material change to the impact assessment, since potential impacts to such birds were assessed and mitigation included on a precautionary basis where necessary.


The ecology and ornithology survey methodology that was implemented to inform the 2008 ES generally followed best practice survey methodology that was relevant at the time. Some of the best practice survey guidance that was referenced, for example, to inform the methodology of the Phase 1 habitat survey, has since been superseded. However, the principles of such guidance have not changed significantly, and so the methodologies that were implemented for the 2007 ecological baseline surveys are considered to remain valid.

The assessment methodology followed in the 2008 ES references guidance published by the Institute of Ecology and Environmental Management (IEEM). This is still regarded as being best practice and so the assessment methodology remains valid.

Since the publication of the 2008 ES, the Joint Nature Conservation Committee (JNCC) have published guidelines in 2010 for minimising the risk of injury to marine mammals from using explosives.

Some nature conservation legislation and policy has been updated since the publication of the 2008 ES. The Conservation (Natural Habitats & c.) Regulations 1994 (as amended 2007) has since been superseded by the Conservation of Habitats and Species (Amendment) Regulations 2010. However, the principles of this legislation have not changed significantly and therefore do not result in a material change to the outcomes of the 2008 ES.

Technical Advice Note (TAN), Nature Conservation and Planning (2009) 5 provides advice about how the land use planning system should contribute to protecting and enhancing biodiversity. It ensures that full account is taken of biodiversity, in accordance with international and national law, and particularly with Section 40(1) of NERC Act 2006. The implementation of TAN 5 since the publication of the 2008 ES would not result in a material change to any of the outcomes of the 2008 ES.

The Welsh Assembly Government (2009) sets out an Environment Strategy in One Wales: One Planet, The Sustainable Development Scheme which aims to create healthy, functioning ecosystems that are biologically diverse, productive and managed sustainably. The implementation of this document since the publication of the 2008 ES would not result in a material change to any of the outcomes of the 2008 ES.


The main source of cumulative impacts would be the construction and operation of the proposed new nuclear power station at Wylfa; this was not addressed in the 2008 ES. However, in the absence of a finalised assessment of the predicted impacts of the proposed new nuclear power station at Wylfa, it is not possible to quantify the predicted cumulative impacts on ecology.

With both projects taking place in tandem, disturbance-related impacts from increased noise and lighting are likely to be greater and continue for longer. This could have an adverse cumulative impact on bats and birds in particular. The construction of the proposed new nuclear power station at Wylfa would also result in habitat loss that would further reduce the availability of foraging resources for the ecological receptors associated with the decommissioning of Wylfa, and therefore result in increased displacement of such receptors. Additional mitigation will be provided if judged to be necessary (in consultation with CCW) in conjunction with the proposed new nuclear power station at Wylfa to offset such cumulative impacts. Wylfa will seek to include joint monitoring of the two projects during the decommissioning/construction phases by an Ecological Clerk of Works. Cumulative impacts may be offset (in agreement with CCW and Horizon) by providing habitat enhancements within an area that would not be impacted by the two projects. Such measures could include those outlined above for providing a net gain for biodiversity. Wylfa will seek to work closely and collaboratively with Horizon (under guidance and consultation with CCW) though it is not possible at this time to state the precise arrangements or mitigation requirements.


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New or revised impacts that were not assessed in the 2008 ES The impacts outlined within the 2008 ES are considered to remain valid. In addition to those impacts, it is predicted that a Moderate Adverse impact on breeding choughs (a receptor of ‘regional importance’) would occur as a result of loss of nesting sites and noise and visual disturbance. Unmitigated, this impact would be significant. Following the implementation of suitable mitigation, this impact would be Negligible and assessed as not significant.


Given the time that will have lapsed between the completion of the 2007 baseline surveys and the commencement of decommissioning works, updated surveys for badgers, otters, water voles, bats and other legally protected species will be undertaken one year before the commencement of any works that could affect these species. These surveys will then be supplemented with on-going monitoring by an Ecological Clerk of Works during such works to ensure legislative compliance.

The mitigation measures described in the 2008 ES for offsetting the predicted impacts remain valid. In addition to those measures, mitigation for the loss of chough nest sites will be provided. This can include the provision of artificial nest boxes within an area that would not be disturbed by the proposed works. Suitable nest boxes will be provided prior to the commencement of the proposed decommissioning works. In addition, the demolition of any buildings that are used by nesting choughs will be undertaken outside of the bird breeding season (which is between the months of March and August (inclusive)).

As a precautionary measure, the mitigation described in the 2008 ES to prevent the incidental mortality of adders will be extended to include all suitable reptile habitat within the site. This will include a targeted reptile survey one year prior to the commencement of the decommissioning works and hand-strimming any suitable vegetation that is present within the site that would be directly affected by the proposed works. If reptiles were found to be present during the pre-decommissioning survey, reptile-proof fencing will be installed around such areas.

The implementation of measures that would provide a net gain for biodiversity will be discussed and agreed with CCW prior to the commencement of decommissioning works. This could include habitat restoration following Final Site Clearance, the provision and maintenance of additional artificial nesting/ roosting sites for birds and bats, the provision of reptile hibernacula within the Wylfa Nature Trail in areas that would not be impacted by Wylfa or the proposed new nuclear power station at Wylfa, and/or financial investment into other nature conservation projects within the local area.

It is anticipated that significant effects on sites of international, national or local importance for nature conservation or their qualifying features would not occur, and so targeted mitigation for such has not been included (see Section 15.3 below). Updated surveys for breeding terns will be undertaken one year prior to the start of any decommissioning works commencing that could impact upon these species, to demonstrate beyond any reasonable scientific doubt that this would be the case.

In addition to the mitigation measures outlined in the 2008 ES, passive acoustic monitoring will be used to provide a more robust means of detecting marine mammals in the vicinity of any planned explosive demolition work immediately prior to the time when such disturbance events would occur. This would minimise the risk of causing injury or disturbance to marine mammals.

Further details regarding the review of the mitigation is provided in Appendix 4.

15.3. Habitats Regulation Assessment (HRA)

Under Article 6 of the Habitats Directive, an assessment is required where a plan or project may give rise to significant effects upon a Natura 2000 site (also known as ‘European Sites’). Natura 2000 is a network of areas designated to conserve natural habitats and species that are rare, endangered, vulnerable or endemic within the European Community. This includes Special Areas of Conservation (SAC) designated under the Habitats Directive for their habitats and/or species of European importance and Special Protection Areas (SPA) classified under Directive 2009/147/EC on the Conservation of Wild Birds (the codified version of Directive 79/409/EEC as amended) for rare, vulnerable and regularly occurring migratory bird species and internationally important wetlands.


Hyder have carried out this assessment, and the full details are provided in an Appendix to the Hyder report30.

Based on the results of the assessment, it is considered that the proposed decommissioning project will not result in significant adverse impacts on the Ynys Feurig, Cemlyn Bay and The Skerries SPA, nor inhibit the delivery of the Conservation Objectives for these sites. Based on the results of the screening, a ‘No Significant Effects Report’ has also been produced (also in the Hyder report).

However, this assessment will be kept under review, particularly in relation to the proposed new nuclear power station at Wylfa. Additionally it may be necessary to undertake further targeted surveys for terns in advance of the decommissioning works in order to try to quantify the number of birds that are likely to be using the off-shore area, immediately adjacent to the Wylfa Head site. This requirement will be agreed with CCW.

15.4. Conclusions

The impacts outlined within the 2008 ES are considered to remain valid. In addition to those impacts, it is predicted that a Moderate Adverse impact on breeding choughs (a receptor of ‘regional importance’) would occur as a result of loss of nesting sites and noise and visual disturbance.

The mitigation measures described in the 2008 ES for offsetting the predicted effects remain valid. In addition to those measures, mitigation for the loss of chough nest sites will be provided. This can include the provision of artificial nest boxes within an area that would not be disturbed by the proposed works. Suitable nest boxes will be provided prior to the commencement of the proposed decommissioning works. In addition, the demolition of any buildings that are used by nesting choughs will be undertaken outside of the bird breeding season (which is between the months of March and August (inclusive)).

Updated surveys for terns, badgers, otters, water voles, bats and other legally protected species be undertaken one year before the commencement of any works that could affect these species.

As a precautionary measure, the mitigation described in the 2008 ES to prevent the incidental mortality of adders will be extended to include all suitable reptile habitat within the site. This will include a targeted reptile survey one year prior to the commencement of the decommissioning works and hand-strimming any suitable vegetation that is present within the site that would be directly affected by the proposed works. If reptiles were found to be present during the pre-decommissioning survey, reptile-proof fencing will be installed around such areas.

The implementation of measures that would provide a net gain for biodiversity will be discussed and agreed with CCW (which will become Natural Resources Wales in April 2013) prior to the commencement of decommissioning works


Wylfa Power Station


16. GEOLOGY, HYDROGEOLOGY AND SOILS

The matters considered under this topic were:

The consequences of any remediation of contaminated ground and/or groundwater, both while carrying out the works and subsequently;

Inadvertent or uncontrolled disturbance or spreading of existing contaminated soils, including movement by windblown dust, entrainment in rainfall runoff, attachment to vehicles and/or inappropriate soil handling operations;

Compaction of soil due to vehicular movements and degradation of soil quality due to construction activities and lay down areas;

Mobilisation of existing contamination by direct rainwater infiltration due to changes in ground cover or the creation of temporary open excavations;

Mobilisation of existing contamination due to changes in water table levels and consequential changes to the groundwater flow regime (e.g. Due to changes in ground covering and rainwater infiltration);

Creation of new contaminant migration pathways (e.g. Due to the creation of boreholes, piles or excavations connecting previously unconnected geological strata);

Inadvertent contamination of soils and/or groundwater arising from temporary storage of contaminated soils, wastes or materials;

Inadvertent contamination of soils and/or groundwater arising from inappropriate use of contaminated soils, wastes or material as in-fill material;

Inadvertent effects on groundwater flow and quality due to in-filling of deep basements and the breaching of basement structures to prevent ponding;

Spills or leaks of radioactive and non-radioactive substances; and

Inadvertent effects of local dewatering on groundwater resources and nearby abstractions, watercourses and sites of conservation interest.

In addition, consideration has been given to changes in the groundwater regime potentially leading to:

Changes to the risk of groundwater-induced flooding (on or off site); and

Changes to the risk of groundwater-induced building damage (on or off site).



For this topic the significance of an impact was determined on the basis of whether:

There would or could be a change in restrictions on land or groundwater use;

A change in monitoring and reporting would be required;

There would be a change in regulatory processes that applied; or

There would be a requirement for remediation. In determining the significance of any impacts consideration was given to local groundwater uses, ecological sensitivity, statutory designations and the effect of distance in reducing any changes to water quality or flow.


Project Impacts and Mitigation Measures Identified in the 2008 ES

A number of potential adverse impacts on geology, hydrogeology and/or soils arising from the decommissioning process have been identified. These potential effects include changes to ground and groundwater quality and/or groundwater quantity (levels and flows), deriving from the following:

Remediation of contaminated ground/groundwater;

Inadvertent or uncontrolled disturbance or spreading of existing contaminated soils;

Creation of new migration pathways;

Direct rainfall infiltration, caused by changes in ground coverage and temporary open excavations, resulting in the mobilisation of existing contamination;

Temporary storage or inappropriate use of contaminated soils and materials, resulting in the inadvertent contamination of ground/groundwater;

Spills and leaks of non-radioactive materials;

The impact of the in-filling of deep basements and the breaching of basement structures on groundwater flow and quality; and

Local dewatering resulting in inadvertent effects on groundwater resources and nearby watercourses and sites of conservational value.

It is predicted that these potential adverse impacts will predominantly arise during the Care and Maintenance Preparations phase and/or the Final Site Clearance phases. Following a precautionary approach, most of the adverse impacts were considered to be potentially significant or key significant. Therefore, mitigation measures have been proposed as set out in Appendix 4 of this document. These involve following best practice and/or all applicable British Standards (BS) or EA Pollution Prevention Guidance Notes. With these in place none of the residual impacts are predicted to be significant. Several of the tasks carried out or impacts arising during Care and Maintenance Preparations may give rise to on-going impacts for Care and Maintenance and beyond, e.g. completion of remediation of contaminated ground, which would give rise to on-going significant benefits or, in the absence of mitigation to prevent it, the creation of a new contaminated area, which could give rise to on-going adverse impacts. However, under normal circumstances, there will be no activities undertaken during Care and Maintenance with the potential to result in new impacts, whether adverse or beneficial. For works were to be carried out during Care and Maintenance (depending on the exact work carried out) the impacts and mitigation measures would be similar to those identified for the Care and Maintenance Preparations phase. During this phase, the quantities of contaminating substances present on site which could give rise to adverse impacts on soil and/or groundwater quality are much reduced compared with the baseline year. Final Site Clearance works will be similar in nature to those undertaken during the Care and Maintenance Preparations phase. The impacts and proposed mitigation measures are therefore as for Care and Maintenance Preparations. The main difference in the case of Final Site Clearance, though, is that the beneficial impact of having completed any necessary remediation of contaminated ground is key significant, as all restrictions associated with any contamination will have been removed. Further information on geology, hydrogeology and soils can be found in Part Two, Section 13 of the original 2008 ES.



Sources of Baseline Information

With reference to table 13.2 of the 2008 ES, the following data relating to groundwater quality has been obtained which impacts on the baseline information: Enviros, 2009, Investigation of


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Chlorinated Solvent Contamination of Water in Sump Adjacent to Wylfa Site, Issue 1, WYA/REP/9143.

Groundwater Quality

Section 13.70 of the 2008 ES states that the EA has no groundwater quality monitoring locations within 5km of the site. The EA’s website has indicated the following river monitoring points are available which may impact on groundwater quality:

Monitoring of the Wygyr stream/ river approximately 2km east of the site. This is currently assigned as being of ‘good’ ecological quality

Monitoring of an un-named stream approximately 0.5km south west of the site. This is currently assigned as being of ‘moderate’ ecological quality

The 2009 Enviros report states that concentrations of chlorinated solvents which exceeded Drinking Water Standards were encountered in a below ground sump to the south of Wylfa. Groundwater quality is therefore likely to be compromised.

Local Sources of Contamination

Section 13.88: The EA website records a significant pollution incident to air which occurred on 27th May 2008. This was approximately 8km east of the site. The 2009 Enviros report indicates that a sump to the south of the site is local a source of contamination from chlorinated solvents, which is causing low level contamination of local streams31. Migration of the contamination within groundwater is likely.

Soils

The 2009 Enviros report indicates that a sump to the south of the site is a source of contamination from chlorinated solvents. This is likely to have caused localised contamination of soils.

Overview of the Baseline

Aside from chlorinated solvents reported above, it is considered that the baseline information presented in the 2008 ES remains current, with no updates required. The baseline date covers the following:

Topography; Geology; Geomorphological features; Hydrogeology; Groundwater; Abstractions, Discharges and Drainage; and Land uses and potential sources of contamination.


Certain aspects of the methodology presented in the 2008 Environmental Statement (ES) are considered to be out of date. Further detail is provided in the following text.

Assessment Criteria

Section 13.17: Updated list of legislation provided as follows:

Water Resources Act 1991 (as amended); Environmental Permitting Regulations 2010; and Directive 2000/60/EC Establishing a framework for Community action in the field of water

policy (Water Framework directive).

It is stated that the Assessment criteria that forms the basis of the impact assessment is based on a combination of professional judgement and ‘other issues’. Since the submission of the 2008 ES,

31 It is noted that whilst very low levels of contaminants have been detected the levels are such that they do not exceed the guideline values for both the Drinking Water Standard (DWS) and Environmental Quality Standard (EQS).

updated guidance has been published, such as the Nuclear Industry Group for Land Quality (NIGLQ), Qualitative Risk Assessment for Land Contamination including Radioactive Contamination (December 2011).

New cumulative impacts At the time of the 2008 ES, no other significant developments were planned for the area surrounding Wylfa. This situation has changed as there is the proposed new nuclear power station at Wylfa. Therefore cumulative impacts are possible, depending upon the timelines of decommissioning and new build. Depending upon timelines, the cumulative impacts that are likely to arise are as follows:

Dusts;

Noise;

Disturbance and mobilisation of contaminants in soils; and

Disruption of groundwater interfaces.


The following additional impacts, over and above those presented in the 2008 ES have been identified as follows:

The impact of the structures on site as a contaminant source.

(Possibly – dependent on timelines) The cumulative impact on Soils and Groundwater flow and quality and to the SSSI site from the proposed Horizon site.

The impact of inadvertent effects of dewatering on groundwater resources and nearby abstractions, watercourse and sites of Conservational interest, including the risk of mobilisation of contaminants into the area.


Specific findings

Inadvertent Effects of Dewatering on Groundwater Resources and Nearby Abstractions, Watercourse and Sites of Conservational Interest:

Section 13.138 refers to the potential impact of dewatering that has been assessed as Negligible and not significant. Mitigation has therefore not been proposed. Detrimental effects to the local groundwater table and SSSI may, in some specific locations result from dewatering.

Whilst there has not been an update in published guidance regarding dewatering, an accepted mitigation measure is to undertake a tiered review of local site specific site investigation and hydrogeological information to inform likely effects and required mitigation measures.

Creation of new contaminant Pathways:

Contaminant pathways may be created by the removal of below ground infrastructure such as tanks. Updated mitigation measures are contained within PPG 27 (Installation, decommissioning and removal of underground storage tanks).

Spills or leaks of non-radioactive substances:

Updated mitigation measures to prevent spills or leaks to include the following:

- General risk assessment of the site, buildings and drainage plans. - Production of an inventory of hazardous substances. - Decontamination of any spilled effluent at source. - Guidance contained with PPG 22 – Dealing with Spills.

Remediation of contaminated ground and/ or groundwater (impacts following completion of the remediation works), if required:

Updated mitigation measure to include appropriate risk modelling and adoption of appropriate sustainable Risk Based Corrective Actions.

Wylfa Power Station

Inadvertent effects on groundwater level, flow and quality due to the in-fill of deep basements and the breaching of basement structures to prevent ponding:


The 2008 ES considers that any remaining below ground structures may be punctured in order to prevent ponding. This action may result in exposing concrete and any associated contamination on the concrete surface to possibly sulphate rich, pH extreme -or saline water. Long term degradation of concrete could adversely affect groundwater. There is currently no published guidance about how to decommission sub surface structures. However, currently accepted mitigations are as follows:

- Undertake a tiered qualitative risk assessment (QLRA) process to understand the structures, the condition of the concrete, impact of saline or groundwater interface in order to understand the potential for the release of ions or contamination from surfaces into groundwater.

- If adverse impact is identified as possible, undertake detailed geo-environmental risk assessment to inform the decommissioning methodologies and to take into account any site specific contamination and geotechnical constraints.

- Removal of sub surface tanks and sealing of voids if appropriate (refer to PPG 27). - Alternatives to puncturing may include back-fill with structural low permeability (e.g.

cohesive or stony cohesive fill) and/or assessment of whether “ponding” (e.g. within granular fill) presents a risk situation.

Localised remediation of contaminated ground and/ or groundwater:

Updated mitigation measures include: - EA Rapid Measurement Techniques. - EA Model Procedures for the Management of Land Contamination (CLR11).

Mobilisation of Existing Contamination by Direct Rainwater Infiltration due to Changes in Ground Cover and the Creation of Temporary Open excavations:

Updated mitigation measure is the characterisation of the likely contamination under buildings/ to inform potential sources of contamination.

16.3. Conclusions

It is predicted that potential adverse impacts will arise during the Care and Maintenance Preparations phase and/or the Final Site Clearance phases. Following a precautionary approach, most of the adverse impacts were considered to be potentially significant or key significant. Therefore, mitigation measures have been proposed following best practice and/or all applicable British Standards (BS) or EA Pollution Prevention Guidance Notes. With these in place none of the residual impacts are predicted to be significant. The 2013 Update has highlighted additional impacts and mitigation that will need to be out in place during decommissioning (following updated guidance) including the production of a Qualitative Risk Assessment for and quality, and a specific review to establish the impacts of dewatering activities.


17. LANDSCAPE AND VISUAL

The landscape and visual impact assessment addresses impacts on the landscape resource (e.g. loss of trees, changes to landform etc.), impacts on views (e.g. changes to scenic composition) and the consequent changes to landscape character.



A three stage process was adopted for the evaluation of the significance of the landscape and visual impacts. First, the magnitude of the landscape or visual impact was assessed. This was followed by an assessment of the sensitivity of the landscape resource or visual receptor. Using these two assessments, the significance of the impact was then judged for each assessment stage. To achieve this aim, the landscape and visual assessment process included:

Assessment of the existing landform, landscape planning context and landscape character, as shown on Figures WYA/LV/1, 3, 4 and 5;

Identification of typical viewpoints from the surrounding area, as shown on the visual appraisal, Figure WYA/LV/2;

Definition of the Visual Envelope of the existing power station site, as shown on Figure WYA/LV/8;

Definition of the Zone of Visual Influence of the decommissioning phases, as shown on Figures WYA/LV/9-11;

Assessment of the magnitude of both landscape and visual impacts;

Assessment of the sensitivity of landscape and visual receptors;

Description of the impact assessed for each of the decommissioning phases, making reference, where appropriate, to night-time impacts and to character; and

Assessment of the significance of landscape and visual impacts. The significance of impacts was determined on the basis of the magnitude of impact in relation to the sensitivity of the existing landscape resource and views, having regard for factors such as:

Statutory and non-statutory designations;

The location, context and rarity of viewpoints;

The expectations and activities of the viewer and the number of people affected;

The extensiveness or otherwise of particular views; and

The popularity of locations and views and their appearance in guidebooks or tourist maps.


During Care and Maintenance Preparations the power station will be in a state of change, with structures being dismantled, modifications being made to the reactor and other buildings, the construction of an Interim Storage Facility and a new gatehouse. There will also be some additional lighting associated with the works during the hours of darkness at the start and end of the working day during winter months which is not expected to have any significant impact. Nevertheless, as a matter of best practice, directional lighting is proposed to reduce light spillage beyond those areas of work which are intended to be lit. It is anticipated that the dismantling works, recladding and modification activities would result in significant impacts on local and medium distance views and key significant impacts on the Area of Outstanding Natural Beauty


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(AONB). There are no significant landscape impacts anticipated, however landscape character may have significant adverse impacts corresponding to the visual impacts on typical viewpoints. During Care and Maintenance there will be an overall reduction in the massing of built form (despite the new ISF building) as a result of the removal of existing buildings on site, (notably the turbine hall). However, visual impacts will be largely adverse due to the shiny nature of reactor building cladding material (standing seam stucco embossed untreated aluminium, assessed in its first few months before it weathers to a dull grey) and loss of subtlety in building composition and tone with some significant negative impacts. The exception is where a clear reduction in visual clutter will be apparent, resulting in significant benefits in AONB views. 20 years into Care and Maintenance the appearance of the re-cladding will be less intrusive, and therefore most of the adverse impacts will no longer be significant. During Final Site Clearance the remaining buildings will be dismantled, including the reactor building. These activities will create visual impacts similar to those during Care and Maintenance Preparations albeit to a slightly reduced extent due to the smaller numbers of buildings and structures involved. Most distant views will remain largely unaffected because equipment likely to be used for dismantling work will be barely perceptible at such distances. Significant adverse visual impacts during Final Site Clearance will be observed from local and middle distance views. Key significant adverse impacts will be observed from two AONB views. These visual impacts will result in corresponding impacts on landscape character. The visual impacts of decommissioning are, in the longer term, overwhelmingly beneficial. Key significant benefits will occur in a number of sensitive viewpoints from the Isle of Anglesey AONB. There will be corresponding benefits to the landscape of the locality, arising from the widespread benefits to views following Final Site Clearance. There will also be a significant benefit on the setting of nearby listed buildings at Cafnan Mill and on the built environment following Final Site Clearance. No planting mitigation is proposed, nor is it considered to be necessary, because significant adverse visual impacts would either be for a limited duration or the proximity and location of these views makes it impractical to provide fully effective screening over and above that which already exists both on and off site. The impact associated with any additional lighting on site at the start and end of the working day during winter months of Care and Maintenance Preparations and Final Site Clearance has been assessed as not significant. Nevertheless, in order to contain the extent of illumination only to those areas which are intended to be lit, it is proposed that any new or replacement lighting installed on site would be directional lighting. Further information on landscape and visual impacts can be found in Part One, Section 14 of the original 2008 ES.



Further to the submission of the 2008 Environmental Statement (ES) the following documents have been published and are therefore considered in this desk top review:

Countryside Council for Wales, Wales Tranquil Areas Map, 2009.

Anglesey Area of Outstanding Natural Beauty Management Plan, 2009- 2014.

Countryside Council for Wales – LANDMAP 2008.

Isle of Anglesey County Council , Landscape Strategy update 2011.

Countryside Council for Wales Draft Regional Landscape Character.32

Countryside Council for Wales Regional Seascape Assessment for Wales 2009.

Countryside Council for Wales – Open Access Land Maps33 32 CCW has confirmed the intention to have this document completed by end of March 2013.

It is understood that the planning policies relevant to the development are the same as those that existed at the time of the 2008 ES was being prepared. Some of the documents listed above require an update to the 2008 ES baseline, as described in the following text. Landscape Landscape Strategy update 2011 - This document replaces the Isle of Anglesey character Areas reported in the 2008 ES paragraph 14.48 and shown on Figure WYA/LV/4. “At County level, the Isle of Anglesey Landscape Strategy Report (Reference 6) divides the area into two character areas;

• Area 2 - North West Anglesey • Area 3 - Amlwch and Environs””

The above two areas have been replaced in the updated strategy with Area 4: North West Coast and Area 5: North West Anglesey. Area 4: North West Coast: - A relatively narrow Landscape Character Area (LCA) which follows the Anglesey coast from the Alaw estuary at Valley around the coast to the Bull Bay area. Inland the boundary follows the geological aspect area boundary reflecting the distinctive rocky nature of this section of coastline. East of Carmel Head, which rises up to 50 metres AOD, the coast has a convoluted pattern. For the most part it is rocky, although Cemaes Bay provides the only sandy beach with Cemlyn Bay providing a local contrasting character, with its brackish lagoon entrapped by a crescent shaped shingle beach. The most conspicuous evidence of human activity is the nuclear power station at Wylfa to the west of Cemaes Village. Area 5: North West Anglesey - This LCA includes the inland elements of LCA 2 defined in the 1999 LANDMAP study. It covers the north west of the island from Amlwch down to the A5/A55 corridor between Valley and Caergeiliog. The key feature of its character is the extensive drumlin field. Interspersed with this landform are a number of hard rocky features such as Mynydd y Garn and Mynydd Mechell. Another, more distinctive feature of the landscape is the development of wind farms to the north of Llyn Alaw. Wales Tranquil Areas Map, 2009 – This document identifies the current state of tranquillity and dark night skies in Wales, breaking it down in to the following three zones which are;

Undisturbed - Countryside usually free of any substantial disturbance in daytime Zone C – Countryside somewhat disturbed by light traffic noise, small settlements, etc Zone B – Countryside subject to significant traffic intrusion and other equivalent

disturbance. Causes of loss in tranquillity include developments such as electrical infrastructure e.g. proposed new nuclear power station, wind farms (on and off shore), 400 and 132 kV overhead lines, road traffic and built up areas. The mapping reflects completed development up to the end of 2008. The landscape of the study area falls predominantly within Zone B and Zone C with some Undisturbed areas with dark night skies at the periphery, away from Wylfa and its associated infrastructure. Open Access Land With reference to the CCW website several areas of Open Access Land identified in the ES 2008 and indicated on Figure WYA/LV/3 have been removed. These include several pockets of cliff edge land east of Cemaes Bay and an area of costal land to the west of Cemlyn Bay. National Trust Wales With reference to the latest Ordnance Survey (OS) 1:50 000 scale mapping sheet 114 there are now a number of parcels of land within the study area which fall under the ownership of the National Trust Wales. These include coastal edge land between Carmel Head and Cemlyn Bay and several pockets of cliff edge land east of Cemaes Bay as well as inland at Mynydd y Garn.

Wylfa Power Station

33 See: http://www.ccw.gov.uk/interactive-maps/outdoor-wales-online-map/open-access-land/open-access-maps.aspx?_dmr=2&_dms=dra&_dmc=SH370930.


Seascape The assessment of the Seascape in the 2008 ES has been limited to the assessment of effects on views from the coastal path. There has been no specific assessment carried out on the Seascape unit. As Wylfa is a significant coastal feature a Seascape assessment will be carried out at a future date when information regarding the proposed new nuclear power station at Wylfa becomes available. It is anticipated that this will be a joint assessment between Wylfa and Horizon (in consultation with CCW and IoACC), though at this stage it is not possible to described precise arrangements. Wales Tranquil Areas Map, 2009 - the Seascape of the study area is recognised as containing land with sea views where LANDMAP has evaluated them as being High or Outstanding. Here the coastline is considered predominantly to be Undisturbed but becoming locally Zone B in the vicinity of Wylfa. Regional Seascape Assessment for Wales 2009 - The document defines Seascape as ‘an area of sea, coastline and land, as perceived by people, whose character results from the actions and interactions of land and sea, by natural and/or human factors.’’. The assessment was carried out at a regional scale, producing 50 regional Seascape units to cover the whole of Wales. Each unit comprises a section of coastal landscape between major headlands, and also includes a defined visual setting zone, running both landward and seaward from the coastline. The study area falls within Regional Seascape Unit 7: Point Lynas to Carmel Head. In terms of the physical characteristics of the area, the assessment makes specific reference to Wylfa:

Coastal land cover – “The nuclear power station at Wylfa is a major feature, even with its conifer planted bund “;

Lighting – “The area is mainly dark with a limited concentration of light at Wylfa”; Tranquillity and wilderness – “The area is generally remote, fairly tranquil and only

significantly disturbed by views of the nuclear power station and, the wind farms”; and Cultural features – “Wylfa nuclear power station dominates the modern Seascape”.

On-going Validity of the methods used in the 2008 ES The methodology in the 2008 ES remains current, although it is recognised that the Guidelines for Landscape and Visual Impact Assessment 2002, 2nd edition is presently being reviewed and updated. The date for the publication of the 3rd edition is not currently known. A Seascape assessment will be carried out once further information on the proposed new nuclear power station at Wylfa becomes available. The methodology will be agreed with CCW and IoACC, and, given the likely scale of nuclear new-build, it is anticipated that the most appropriate approach will be to carry out a joint assessment with Horizon. New cumulative impacts The assessment of cumulative effects at this stage is limited by the lack of information available for other developments set out in the Pre-Application Opinion Scoping Report. However it is likely that the construction and operation of the proposed new nuclear power station at Wylfa would reverse the beneficial effects identified in the 2008 ES and in some cases there would be the potential for significant cumulative adverse effects as a result, particularly if the proposed new nuclear power station at Wylfa results in changes to the woodland and artificial drumlin landscape designed by Dame Sylvia Crowe as mitigation associated with Wylfa. It is understood this designed landscape is in the process of being reviewed by Cadw (the Welsh Government’s historic environment service) in terms of it being included in the register of landscapes, parks and gardens of historic interest in Wales. An assessment of the Seascape cumulative effects will be carried out once further information on the proposed new nuclear power station at Wylfa becomes available. New or revised impacts that were not assessed in the 2008 ES


The reporting of the effects in the 2008 ES would not change, but in light of the change in the baseline receptor descriptions, the following updates have been identified.

Paragraph 14.70 of the 2008 ES states: There will be significant adverse visual impacts on local and medium distance views (Viewpoints 11, 12, 13, 15, 16, 18 and 23) and one Open Access Land view (Viewpoint 14), and key significant impacts from two AONB views, (Viewpoints 24 and 25), resulting from views of dismantling works and re-cladding and modification works to the reactor building. With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 14 is located on land now owned by the National Trust Wales but not identified on the CCW website as Open Access Land. Paragraph 14.77 of the 2008 ES states: At this stage, most buildings and ancillary structures, with the exception of the reactor building and the new radioactive waste storage building will have been removed. This will result in a reduction in building massing apparent in local and medium distant views. However, visual impacts will be largely adverse, due to the shiny nature of cladding material and loss of subtlety in building composition and tone, resulting in the reactor building appearing more prominent in certain views. Significant visual impacts during the Care and Maintenance phase will be observed in views represented by Viewpoints 11, 12, 13, 15 and 16 and Open Access Land view (Viewpoint 14), as a result of the newly re-clad and modified reactor building. With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 14 is located on land now owned by the National Trust Wales but not identified on the CCW website as Open Access Land. Paragraph 14.89 of the 2008 ES states: Significant adverse visual impacts during Final Site Clearance will be observed (Photographs 11, 12, 13, 15, 16, 18 and 23) and Open Access Land view (Photograph 14), and key significant adverse impacts from two AONB views, (Photographs 24 and 25), due to the demolition of remaining buildings/structures. With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 14 is located on land now owned by the National Trust Wales but is not identified on the CCW website as Open Access Land. Paragraph 14.95 of the 2008 states: Key significant beneficial impacts would occur from views represented by Photographs 11, 12, 13, 18, 23, 24 and 25 and Open Access Land view (Photograph 14), due to the improvement in the view when compared to the baseline. With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 14 is located on land now owned by the National Trust Wales but is not identified on the CCW website as Open Access Land. Paragraph 14.96 of the 2008 ES states: Significant beneficial impacts would occur from a number of other views (Photographs 8, 9, 15, 16, 17, 22 and 26N) and Open Access Land view (Photograph 10) due to the improvement in the view when compared with the baseline With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 10 is located on land now owned by the National Trust Wales as well as being Open Access Land. Table 14.11 of the 2008 ES comments on the following Viewpoints:

Viewpoint 10 - Character Area - Mynydd y Garn: View north-east from William Thomas monument at Mynydd y Garth


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Within Area of Outstanding Natural Beauty Open Access Land.

With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 10 is located on land now owned by the National Trust Wales as well as being Open Access Land.

Viewpoint 14 - Character Area - North Coast Hinterland: View west from Llanbadrig Point Within Area of Outstanding Natural Beauty Open Access Land

With reference to the latest OS 1:50 000 scale mapping sheet 114, Viewpoint 14 is located on land now owned by the National Trust Wales but is not identified on the CCW website as Open Access Land. With reference to paragraph 14.96 of the 2008 ES, an assessment of the Seascape effects will be carried out once further information on the proposed new nuclear power station at Wylfa becomes available. On-going Validity of proposed mitigation in the 2008 ES It is not anticipated this or the new baseline data identified above will require any changes to the mitigation in the 2008 ES.

17.3. Conclusions The methodology in the 2008 ES remains current, although it is recognised that the Guidelines for Landscape and Visual Impact Assessment 2002, 2nd edition, is presently being reviewed and updated. The date for the publication of the 3rd edition is not currently known. It is not anticipated this or the new baseline data identified above will require any changes to the mitigation in the 2008 ES. A Seascape assessment will be carried out once further information on the proposed new nuclear power station at Wylfa becomes available. The methodology will be agreed with CCW and IoACC, and it is anticipated that this will be carried out jointly with Horizon.


18. NOISE AND VIBRATION

The noise and vibration assessment has taken into account noise and vibration deriving directly from the Wylfa site, as well as that due to site traffic (including the use of HGVs). The traffic data used in the assessment took into account predictions of future changes in background traffic.



For this topic significance has been determined largely on the basis of the change in noise level and receptor sensitivity with residential properties being considered as high sensitivity. Project Impacts and Mitigation Measures

For general site works (with no mitigation) worst-case noise impacts during Care and Maintenance Preparations are predicted to be significant at seven residential locations and at the Wylfa Power Station social club located within the area of the former Simdda-Wen. At five receptors the impacts are assessed as not significant. The assessment of direct site noise is pessimistic in that it assumes that all of the plant/equipment on the site is operating at the centre of the closest work area to the receptor in which work is being carried out. In reality, plant would be used intermittently and on different parts of the site, so it is likely that noise levels will be lower than those predicted. During the Care and Maintenance phase no noise sources of relevance to receptors would operate on site (with perhaps some temporary exceptions, e.g. if the reactor building cladding required complete replacement, and demolition of the radioactive waste storage facility), thus no significant or key significant effects are anticipated. Following Final Site Clearance no features relating to the generation of noise would remain on the site. For Final Site Clearance noise impacts are expected to be Moderate at most. Four residential receptors are assessed as being subject to significant noise effects whilst impacts on another eight residential receptors and the Power Station social club are expected to be not significant. However it is unknown if these locations will be in use or existence at the time of Final Site Clearance or if there will be more receptors in the area by that point. Traffic noise and vibration levels from the decommissioning process are assessed as not significant at all receptors due to the low magnitude of change involved and small numbers of people affected. Traffic noise levels for the Care and Maintenance phase and following Final Site Clearance are reduced compared to the ‘without decommissioning’ scenario as the station would have significantly reduced levels of staff compared with those required to maintain the station in a quiescent state. For noise impacts during the Care and Maintenance Preparations and Final Site Clearance phases that have been assessed as significant, mitigation measures have been proposed as set out in Appendix 4 of this document it is not possible to determine the noise level reduction that would be gained through use of mitigation. However, mitigation will reduce noise levels and, depending on the level of reduction, will also potentially reduce the significance of noise impacts. Therefore for general site works during Care and Maintenance Preparations and Final Site Clearance, the post mitigation worst-case noise impact will possibly be significant. During Care and Maintenance there will be no construction or demolition noise on the Wylfa site, except for isolated periods when significant works may be carried out as necessary (see above). There will also be much less traffic associated with the site as the site will be routinely de-manned and traffic movements will only take place for periodic inspections etc. and also retrieval of waste packages. There will be no generating noise from Wylfa during this period.


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Following Final Site Clearance no features relating to noise generation would remain on the site, so the reduction in noise level will be permanent. Noise levels during these phases are therefore predicted to be lower at receptors than in the baseline year 2007, the nearest residential receptors being predicted to experience average noise levels just below 50 decibels. Further information on noise and vibration can be found in Part Two, Section 15 of the original 2008 ES.


New / revised environmental data At the time of the baseline noise surveys in 2007, with the Wylfa site generating, it was not possible to directly measure noise levels at receptors which would prevail following decommissioning. The 2008 Environmental Statement (2008 ES) baseline was established using a combination of measurement and noise modelling techniques. The baseline monitoring carried out in 2007 was agreed with the Environmental Health Department of IoACC. Baseline measurement of noise levels was carried out at representative locations around the site with Wylfa generating. The measured values were then reduced by the amount which Wylfa influences them, leaving what was considered to be the true background noise in the absence of any generating noise. Consultation has been carried out with the Principal Environmental Health Officer (EHO) (Pollution) at IoACC in January 2013. IOACC indicated that it has carried out baseline noise surveys in 2012. The 2008 ES baseline data has therefore been reviewed against data currently being collected by IoACC, although the monitoring locations used by IoACC differ from those used for the 2008 ES baseline. Direct comparison between the two datasets is therefore not possible. During the consultation with IoACC, it was indicated that some receptors considered in the 2008 ES assessment have subsequently been demolished. Further investigation of the status of the receptor locations considered in the 2008 ES has therefore been carried out, as follows:

Cafnan is still an occupied building and farm (used for noise and dust monitoring by IoACC), although it is currently in a poor state of repair;

Pont Cafnan is still standing as a building, although it is currently in a poor state of repair;

Cestyll is still standing although it is currently in a poor state of repair; Pennant is still standing although it is currently in a poor state of repair, with most

entrances blocked up and a reinforced gateway in place; Tan yr Allt is confirmed as still standing, although it is currently in a poor state of

repair, with most entrances blocked up and a reinforced gateway in place; The Firs is confirmed as still standing, although it is currently in a poor state of repair,

with most entrances blocked up and a reinforced gateway in place; Tregele, no change; Pen Lon has been demolished ; Pentregof is still standing as a building ; Cemaes Village, no change; Simdda Wen has been demolished ; Ty Croes is confirmed as still standing, although it is currently in a poor state of repair,

with most entrances blocked up and a reinforced gateway in place; and Haul a Gwynt is confirmed as still standing, although it is currently in a poor state of

repair, with most entrances blocked up and a reinforced gateway in place.

During consultation with IoACC, it was indicated that further baseline monitoring at this stage would not serve any purpose. It was indicated that the baseline would be established at the time of the submission of the Section 61 Consent Application process (discussed in more detail below) as factors that contribute to ambient noise levels at present would possibly change by the time decommissioning works commence.

On-going Validity of the methods used in the 2008 ES The methodology followed in the 2008 ES for predicting decommissioning noise impacts is in accordance with BS5228: 1997 Parts 1 and 2: Noise and vibration control on construction and


open sites, 1997. Although BS 5228: was replaced by BS5228: 2009, the findings of the 2008 ES would not change and are therefore considered to remain valid. The 2008 ES assessment of the decommissioning noise impacts is based on assumptions regarding the proposed works and equipment used to make the predictions. Detailed method statements would not be available until after contractors have been appointed and for this reason it was indicated during consultation with IoACC that no benefit would be gained in carrying out further predictions that rely on the same or similar assumptions. It was agreed with IoACC that in the absence of definitive method statements for the decommissioning works, and in order to adequately consider cumulative construction and decommissioning noise impacts, a Section 61 Consent Application would need to be submitted. This would allow for the appointed contractors to prepare definitive method statements that would allow more accurate prediction of noise impacts. The Control of Pollution Act 1974 (COPA) is specifically concerned with developments that significantly impact upon neighbouring premises through noise or vibration. Companies intending to carry out construction, demolition or maintenance works upon buildings, structures or roads are encouraged to engage with the council for 'Prior Consent'. The Section 61 agreement would be a formal agreement between the developer / contractor and the IoACC where noise levels, hours of work and any mitigation are agreed upon. The developer would typically submit an application form to the council at least 28 days before the intended work is due to commence, the authority then has 28 days in which to make a decision. It is however advisable that application is made well in advance of 28 days prior to commencement of works to avoid unnecessary delays. Traffic Noise Impacts Traffic data used for the 2008 ES has been revised and is likely to undergo further revision. An initial review of the traffic data indicates that the predicted changes in traffic are unlikely to be significant from a noise perspective.

The Design Manual for Roads and Bridges (DMRB) Volume 11, indicates that a +25% or -20% change in traffic composition will result in an increase or decrease in road traffic noise of approximately 1 dB (A) and would therefore be considered significant. It is considered unlikely that revised traffic data will differ significantly from the data used in the 2008 ES. The revised traffic data will however be considered as part of the Section 61 Consent Application described above.

New cumulative impacts During consultation, IoACC indicated that the 2008 ES failed to consider the cumulative noise impacts from the decommissioning and the construction of the proposed new nuclear power station at Wylfa. It was however agreed that an accurate assessment of cumulative noise impacts would not be possible at this stage due to a lack of detailed information, particularly with regard to the proposed new nuclear power station at Wylfa. the assessment of cumulative noise impacts would be addressed through the Section 61 Consent Application process. It has been suggested by IoACC that a mechanism for presenting cumulative noise impacts for construction and decommissioning be negotiated between the owners of the respective sites.

As discussed above, IoACC suggested that an integrated noise monitoring plan be implemented to consider noise impacts for decommissioning of Wylfa and for construction of the proposed new nuclear power station at Wylfa. The noise monitoring plan would therefore require collaboration between the owners of the respective sites.

New or revised impacts that were not assessed in the 2008 ES As agreed with IoACC, a revised noise impact assessment is not considered necessary at this stage and cumulative noise impacts will be presented as part of a Section 61 Consent Application. The predicted noise impacts for the Section 61 Consent Application would require the appointed contractor(s) to prepare definitive method statements to allow an accurate prediction of noise impacts and design of appropriate mitigation measures.



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Until such time that detailed working methods are defined, it is not possible to determine the noise level reduction that would be gained through the use of mitigation. However, mitigation will reduce noise levels and, depending on the level of reduction, will also potentially reduce the significance of noise impacts. The Section 61 Consent Application would provide for a more robust assessment of the noise impacts and the identification of more specific mitigation measures to reduce noise impacts. In terms of Section 61 Consent, decommissioning noise impacts would be assessed in line with 'Best Practicable Means (BPM)' found in BS5288:2009. The Section 61 Consent would ensure that the most appropriate mitigation is implemented for the proposed works to be carried out. The mitigation would need to be specific and would need to demonstrate to IoACC that agreed noise limits will be met. If the provisions of the Section 61 Consent are not adhered to, IoACC can take legal action. Mitigation measures to be included in the Section 61 Consent Application would typically include the following:

The hours of working should be planned and account should be taken of the effects of noise upon persons in areas surrounding site operations and upon persons working on site, taking into account the nature of land use in the areas concerned, the duration of work and the likely consequence of any lengthening of work periods;

Where reasonably practicable, quiet working methods should be employed, including use of the most suitable plant, reasonable hours of working for noisy operations, and economy and speed of operations. Site work should be programmed, when appropriate, so that haulage vehicles will not arrive at or leave the site between 1900hrs and 0700hrs;

Noise should be controlled at source and the spread of noise should be limited, through implementation of general measures such as:

• avoiding unnecessary revving of engines and switching off equipment when not required;

• keeping internal haul routes well maintained and avoiding steep gradients; • using rubber linings in, for example, chutes and dumpers to reduce impact noise; • minimising drop height of materials; and • starting-up plant and vehicles sequentially rather than all together.

The movement of plant onto and around the site should have regard to the normal operating hours of the site and the location of any sensitive receptor locations as far as is reasonably practicable;

The use of conventional audible reversing alarms may cause problems on some sites and alternatives are available. Audible reversing warning systems on mobile plant and vehicles should be of a type which, whilst ensuring that they give proper warning, has a minimum noise impact on persons outside sites. Where practicable, alternative reversing warning systems should be employed to reduce the impact of noise outside sites; and

A method of noise measurement should be agreed prior to commencement of site works.

During consultation with IoACC, it was indicated that mitigation measures suggested in the 2008 ES, as set out in Table 15.12, tend to be reactive rather than proactive. A typical example would be:

‘Designated site contact to whom complaints/ queries about construction/demolition activity can be directed – any complaints to be investigated and action taken where appropriate’.

IoACC suggested that an integrated noise monitoring plan be implemented to consider noise impacts for decommissioning of Wylfa and for construction of the proposed new nuclear power station at Wylfa. The noise monitoring plan would therefore require collaboration between the owners of the respective sites. IoACC also indicated that they would be looking for a noise monitoring system that allowed for warnings to be issued when agreed noise trigger levels are reached so that proactive actions could be implemented to rectify noise problems before complaints were made. It was also indicated that the monitoring system should allow for IoACC to access data in real time.


The noise trigger levels to be adopted for the noise monitoring would be agreed as part of the Section 61 Consent. Mitigation measures would also be embedded into the Environmental Management Plan (EMP). Refer to the Ecology section of this report for information relating to mitigation of noise impacts to marine mammals.

18.3. Conclusions

As agreed with IoACC, a revised noise impact assessment is not considered necessary at this stage and cumulative noise impacts will be presented as part of a Section 61 Consent Application. Until such time that detailed working methods are defined, it is not possible to determine the noise level reduction that would be gained through the use of mitigation. However, mitigation will reduce noise levels and, depending on the level of reduction, will also potentially reduce the significance of noise impacts. The Section 61 Consent Application would provide for a more robust assessment of the noise impacts and the identification of more specific mitigation measures to reduce noise impacts. In terms of Section 61 Consent, decommissioning noise impacts would be assessed in line with 'Best Practicable Means (BPM)' found in BS5288:2009. The Section 61 Consent would ensure that the most appropriate mitigation is implemented for the proposed works to be carried out. The mitigation would need to be specific and would need to demonstrate to IoACC that agreed noise limits will be met. The predicted noise impacts for the Section 61 Consent Application would require the appointed contractor(s) to prepare definitive method statements to allow an accurate prediction of noise impacts and design of appropriate mitigation measures.


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19. SOCIO–ECONOMIC

The main impacts considered under this topic were:

Changes in direct and indirect employment supported by the power station, including the scope for retraining and reskilling of the existing power station workforce to enable their employment in the decommissioning works;

Effects on employment and unemployment levels in the local economy, and changes in the structure of local employment;

Changes in local expenditure by power station employees, magnox and its contractors;

Immigration and emigration of power station employees and contractors and resulting changes in local population levels and structure;

Changes in the demand for temporary accommodation;

Changes in the demand for permanent housing and effects on the local housing market;

Changes in pupil numbers in local schools; and

Changes in the demand for community/amenity facilities and services. Other impacts which have been considered in the assessment, but in less detail, include:

Changes in commuting patterns;

Effects on key local economic sectors (e.g. Tourism, agriculture, fisheries);

Changes in the development potential of the area; and

Changes in the incidence of social problems including crime and disorder.


These impacts were primarily considered in respect of the implications of decommissioning for the local economy defined as the Isle of Anglesey. The choice of study area for the socio-economic assessment largely reflects the residential distribution of the existing power station workforce. Just over 87% of the current power station workforce resides within the Isle of Anglesey itself. The residual workforce (13%) commutes from other parts of Wales and parts of England. Most of the predicted socio-economic impacts arising from decommissioning are likely to be contained within the Isle itself. In order to capture a range of more localised impacts, the Isle of Anglesey has been sub-divided into three areas as follows:

Anglesey North - based on the communities immediately surrounding the power station (including Cemaes Village and Amlwch);

Anglesey West – based on the town and hinterland of Holyhead;

Anglesey South – based on the settlements/hinterland in the south of the Isle stretching to the mainland.


The significance of impacts was determined on the basis of:

The magnitude of the predicted impact (defined as the percentage change in the impact receptor compared with the baseline);

The geographic extent of the impact;


The duration and reversibility of the impact;

The capacity of the local economy to absorb or adjust to the impact; and

Typical rates of socio-economic change experienced in the study area (e.g. Recent rates of population and employment growth).


The Isle of Anglesey has the smallest economy in the whole of Wales valued at £646 million in 2005 which results in a gross value added (GVA) of £9,392 per head of population (the lowest in the UK). Any decommissioning effect has to be considered in relation to this starting position. Wylfa power station has become an important part of the Anglesey economy over the last thirty years. It has been one of the few large scale employers outside the public sector since 1971 when the station started to generate electricity. The loss of the station (based on 2008 staff levels) will lead to the loss of 750 direct jobs (650 staff plus 100 contractors) and could result in the loss of a further 108 full time equivalent jobs elsewhere from the local economy. These jobs have a high productivity per employee so their loss inevitably reduces gross value added still further. Whilst the local economy is generating new employment opportunities, there is limited scope for attracting jobs with a similar level of productivity. The loss of the power station will remove a stable source of predominantly male, high-wage employment from the local economy. The station also performs a broader community role by helping to sustain a number of critical services (both public and private) needed by the workforce and their dependents. Schools, libraries, doctors, nurseries, community and social care day centres all rely on sufficient need to sustain their demands for scarce public sector support. The Socio-Economic Section has identifed and, where possible, quantified these effects through an examination of Wylfa’s role as an employer and its indirect impacts as a part of the Isle of Anglesey economy. Some of the key facts identified are:

Wylfa employs 3.5% of the employed workforce of the Isle of Anglesey;

A further 406 resident adults and 450 children are estimated to be affected by the closure as a result of being part of families of Wylfa workers;

Around 173 adults (resident workers and partners) and 67 children (representing 98 households) are expected to migrate away from the island entirely after the end of Care and Maintenance Preparations;

In addition to the jobs lost from the station itself, a further 108 jobs are supported through expenditures of the station;

30,000 visitors per annum to the Information Centre will be lost, although this is not expected to cause changes in the number of visitors to the Isle of Anglesey;

Average wage levels are likely to be depressed by 2.1%; and

Temporary boost to the tourist accommodation sector from an influx of an additional 400 contract workers per annum over two months during station outages will be lost.

Outside the quantifiable effects there are the less tangible effects of losing a longstanding employer with a significant physical and community presence established over a 40+ year period (e.g. through being active within the local community through the actions of its employees and as a corporate body interested in maintaining the goodwill of the community – otherwise known as ‘Corporate Social Responsibility’). The key aim of the Socio-Economic Section (Part Two, Section 16 of the original 2008 ES) has been to place the effects of decommissioning the station within a wider socio-economic context. As the majority of employees at the site come from within the Isle of Anglesey, the focus for this work has been to assess the closure’s impact in relation to the economic performance of the Isle of Anglesey itself and its communities. A series of objective tests have been established for examining how ‘significant’ the closure will be for the Isle of Anglesey economy and community. These tests have been taken from good practice established in assessing decommissioning


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impacts within the UK. These tests need to be considered in the round so an overview is taken on the significance of Wylfa’s closure. The overall assessment takes into account the scale of effect; degree of adjustment required by the locality; reversibility of the effect and so forth. These tests are focused on quantitative criteria to maintain objectivity within the assessment although the use of these criteria is not intended to deny the importance of the more intangible aspects of a large closure on a community. The assessment shows the local economy’s development has been shaped by the Isle of Anglesey’s physical attributes of an attractive coastline and remoteness that has encouraged certain industries to grow but discouraged others. A remote coastal location has provided access to water for cooling a nuclear power station; the space for coastal and countryside related recreation and a convenient sea crossing point to Ireland. Tourism and transport, as well as power generation, have grown and encouraged a range of associated industries to develop, including electrical energy-intensive aluminium smelting using low cost power from the power station (the smelter plant ceased operations in 2009 and went into a mothballed state when the contract for cheap power expired, which was partially in anticipation of the original 2010 shutdown date for Wylfa. No new contact was negotiated even when Wylfa’s generation life was extended, so the plant became uneconomical and smelting operations ceased. Some activity continues at the site in the manufacture of aluminium products. A remote coastal location also offers an attractive amenity value to households looking for the benefits of a rural lifestyle including retirement households. The Isle of Anglesey is particularly attractive to older households who may have been able to use the proceeds from house sales in higher cost areas of the country to fund house purchases in this area. This demographic profile increasingly dominated by older people has, in turn, an influence on the mix of services and housing available in the area. Whilst a remote coastal location can attract certain types of industry and person, distance from centres for population acts as a significant break on growth potential for others. Many of the nationally significant, high growth sectors of the economy, like business and financial services, tend to thrive in larger accessible population centres with good connectivity to customers, a labour force and other businesses that they work with. These sectors are weakly represented in the island’s economy currently. The area has also consistently lost younger, working age people, possibly reflecting a mix of limited work opportunities and lifestyle choices. Relatively speaking, other parts of the North Wales sub region seem better able to deliver the densities of population/business and connectivity to the wider economy and access to administrative centres than the Isle of Anglesey itself. The Anglesey economy has tended to under-perform in relation to the Welsh average across a number of indicators, including: gross value added per head of population; rates of new business formation; migration of working age population; unemployment; and economic activity. The problems of remoteness are magnified for the remote North Western corner of Anglesey which is ideal for the power station in terms of accessing cooling water but some distance away from key centres of population both within the Isle of Anglesey itself and more widely within the UK. As the composition of the population shifts towards a higher proportion of non-economically active (reinforced by demographically selective migration, especially of retirement-age people) and lower productivity sectors of the economy (e.g. tourism), output per head of population is going to come under further downward pressure. The risk is that the Isle of Anglesey settles into a low performance equilibrium as expectations within the labour market are lowered resulting in a population with few incentives to improve skills (unless the intention is to exploit them somewhere else) and employers who have no particular demand for the skills. The net result is that both sides of the labour market reinforce each other downwards. Whilst the assessment has identified relative performance issues, the economy is still creating jobs, albeit at a slower rate than the general economy. The trends suggest that the economy can make the adjustment to the loss of employment and reverse the absolute effects of closure given


time, but is unlikely to be able to replace the high quality jobs provided by Wylfa with new jobs of an equivalent quality. The assessment has also identified an array of public sector initiatives aimed at changing the direction of the study area and preventing it from settling into a low performance equilibrium. The Isle of Anglesey County Council is committed to creating a modern infrastructure base to support diversification of the study area economy. The NDA strategy has also identified the area as a priority for support. The Isle of Anglesey (along with northern and western Wales) is subject to the European Union Convergence and Regional Competitiveness and Employment Objectives (under the Cohesion Policy 2007 – 13), which provides funding to poorer regions of the EU, targeting certain things such as transport and employment. Whilst the assessment of the proposed decommissioning project has not met all the criteria used to identify key significant effects, the decommissioning process will, nevertheless, produce a number of significant impacts, including:

The long term adverse impact on employment opportunities in the sub area containing the site, known as Anglesey North, that will occur by the end of the Care and Maintenance Preparations ;

A short term, Major Adverse impact on unemployment especially in Anglesey North at the end of the Care and Maintenance Preparations ; and

The generation of employment for almost a decade during Final Site Clearance represents a significant impact for the immediate cluster of wards. The impact is most likely to be short-term Major Beneficial, but the true impact that this will make in terms of relative employment types and levels at the time is not possible to predict at this time.

The ability of Magnox to directly avoid or reduce the significant adverse employment impacts during decommissioning is limited. The scope for redeployment or retraining of staff within Magnox will be constrained (especially geographically – redeployment of skills within the company will inevitably require personnel to relocate to another site elsewhere in the UK. Also, this in itself will be constrained in terms of time, as Wylfa will be one of the last sites to go through the decommissioning cycle, so most of the other Magnox sites will already be in the quiescent Care and Maintenance state by the time Wylfa is well advanced into Care and Maintenance Preparations) and, although assisting the individuals affected, this will not prevent the long term loss of stable well paid employment opportunities from the local economy. The mitigation measures are not expected to lead to any sizeable reduction in the magnitude or significance of the predicted socio-economic impacts described above. During Final Site Clearance, many predicted socio-economic impacts are beneficial. Opportunities exist to minimise the leakage of economic benefits from the local economy by encouraging the use of local contractors and local labour. The site operator will encourage its contractors to make use of locally sourced labour, materials and services as far as practicable. Measures will be undertaken to provide contractors with information on suitably qualified local companies capable of involvement in the decommissioning work. The cumulative impacts associated with the closure of Anglesey Aluminium Metals (AAM) compound the effects identified for the decommissioning of the station. The loss of AAM will lead to a further loss of 652 directly employed jobs in the company and a further 248 jobs in the rest of the economy through indirect and induced effects. Around 95% of these jobs are occupied by people resident in the Study Area. The average wage attached to these jobs is 65% greater than the average for jobs within the local economy. AAM’s loss will also remove an active apprenticeship programme employing 12 apprentices on site who have achieved success under the ‘Engineering Employers Federation Apprentice of the Year Competition for Wales’. The loss of the smelter reinforces some of the trends identified earlier as opportunities for higher productivity work are removed. Growth, therefore, becomes more reliant upon the other sectors where the local economy has a comparative advantage but where the added value tends to be lower.


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Further information on the socio-economic impacts can be found in Part Two, Section 16 of the original 2008 ES.



Socio-economic elements of the baseline that directly relate to the impacts section and require updating since the preparation of the 2008 Environmental Statement (2008 ES) are included below.

Population Growth and Distribution within the Study Area

The population of the Isle of Anglesey (the study area) in 2010 was 68,600. Anglesey North34 (including the settlements of Cemaes Village and Amlwch) accounts for only 13,215 residents (less than 20% of the Island’s population). [NB the most recent data reflecting the population of Anglesey is from the 2011 Census which states the population was 69,751 in 2011, however, at the time of this update comparator data for wards had not been released].

Population growth is a significant factor in determining future economic growth. Population growth is a product of the net difference between births and deaths within an area (natural growth) plus the net movement of people into the area (migration). The most recent actual data shows that there have been more deaths than births in the Isle of Anglesey in the five years up to mid-2007/08. Despite there being slightly more births than deaths projected for the first few years of the projection period, natural change is projected to become negative in 2018/19 and this is expected to continue for the rest of the projection period.

The Isle of Anglesey is one of only eight local authorities in Wales that are projected to generally see more deaths than births across the whole projection period. Without a positive net inward migration, the Isle of Anglesey would see a declining population (Welsh Assembly Statistics, National Statistical Directorate for Wales). Over a ten year period, the population of the study area has increased (using official mid-year estimates from 2001 and 2011) but at a much slower rate than Wales (1.60% compared to 5.28%).

Economic Activity and Employment Rates

Economic activity rates on Anglesey are slightly higher than the average for Wales as a whole. Some 75.7% of the Island’s working age population is either in employment or actively seeking work, compared to an average rate of 73.2% for the Wales region. The economically active population of the Island was estimated at 32,200 in July 2011- June 2012 (Anglesey Labour Market Profile, NOMIS). The overall employment rate is 71.8% for the Isle of Anglesey which includes employees in employment of 24,800 and a further 5,400 self-employed workers (the equivalent rate for Wales is 67.0%) (Anglesey Labour Market Profile, NOMIS).

At the time of writing, 2011 Census ward data had not been released. However, 200135 Census data for Anglesey North area showed activity rates were particularly low where only approximately

34 Anglesey North includes the wards of Amlwch Port, Amlwch Rural, Llanbadrig, Llaneilian, Llanfaethlu, Llanerch-y-medd, Mechell and Moelfre. 35 At the time of writing it was unclear as to where economic activity data relating to Anglesey North was obtained within the 2008 ES.

65% (4,462) of the working age population were economically active, 9% below the UK average (74%).

Unemployment

Data on levels of unemployment within the study area relate to the position in 2012. In November 2012 there were 1,907 study area residents out of work and claiming Job Seekers Allowance (JSA), representing 4.6% of the resident population. 333 of these were living in Anglesey North nearest to Wylfa. Unemployment rates in the study area are slightly less than the rates for Wales and the UK. Between July 2011 and June 2012, 6.8% of working age residents in Anglesey were unemployed compared to 8.3% of working age residents in Wales and 8.1% of residents in the UK. In Anglesey North, approximately 4% of working age residents were unemployed (333).

Another measure of unemployment concerns the time that individuals spend claiming JSA. In November 2012, 1.5% of all JSA claimants in Anglesey had been claiming for over 12 months which is higher than both Wales (1.1%) and the UK (1.0%). Duration can also be considered in terms of age groups. Anglesey North has seen an increase in the numbers of people claiming JSA for over 12 months (by approximately 3.4%).

Tourism Accommodation

The 2008 Anglesey Accommodation Bed Stock Survey identified there were 2,237 serviced accommodation bed spaces on the Island along with 6,645 self-catering bed spaces and 28,720 camping and caravanning bed spaces (Wylfa Nuclear New Build: Construction Workers Accommodation, Position Statement - March 2011).

Housing Stock and Markets

The 2011 Census identified there were 30,594 dwellings on the Isle of Anglesey (however, in March 2011 there were 33,944 houses recorded on the Council Tax Register in the Isle of Anglesey (Anglesey InfoBase)). The 2011 Census also identified that 12.7% (3,899) were social rented (rented from the local authority), 1.9% (588) were social rented (other), 12.1% (3,699) were private rented (private landlord or letting agency), 2% (625) were private rented (other) and 2.4% (749) were living rent free.

In November 2012, the average property price in Anglesey was £133,823, compared to the Welsh average of £115,202. The average house price for a detached house was £177,669 in Anglesey compared £176,138 in the rest of Wales, whilst a terraced house in Anglesey had an average price of £82,934 compared to £77,725 in the rest of Wales. In September 2012 the number of house sales was 78 (Anglesey InfoBase).

19.3. The Wylfa Station Baseline

Station Expenditure and Use of Local Suppliers

Data on expenditure by Wylfa with local businesses shows direct contracts to a value of £3.2m in 2011/12. Annual salary costs per annum (gross) were £42.6m in 2011/12.

Estimates for the total costs for the site clearance are £929m.

Station Employment Levels and Baseline Resource Plan


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Permanent staff numbers at Wylfa are currently 543 with 46 fixed term contract holders, giving a total of 589 staff employed directly at the site. Of the 589 staff, 489 are male and 100 are female. The age profile of the staff is shown in Table A 4, and the future resource plan the site during Care and Maintenance Preparations in Table A 5. Contractor numbers at Wylfa vary, but around 100 would be typical. During decommissioning (primarily Care and Maintenance Preparations and Final Site Clearance) contractor numbers will also vary, but experience from other Magnox sites shows that 100 – 150 contractors will be on-site at any given time.

Table A 4: Age of Wylfa employees 2012 (excluding contractors).

Age Numbers of Staff

Up to 25 28

26-35 93

36-49 229

50-64 233 65 plus 6

Table A 5: Wylfa Resource Plan 2014 – 2025 - Staff Numbers, direct employees only, excluding contractors. Contractor numbers will be typically 100 – 150.

2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

575 570 399 375 353 280 250 230 220 210 200 175

Welsh Language

A survey undertaken in 2012 as part of the Shaping the Future initiative (for Wylfa and Traws) received 364 replies (out of 842 potential recipients). Out of those replies, 37% stated they understand the Welsh language (includes speaking, reading and writing). 2011 Census data states that 38,568 people within Anglesey are able to speak Welsh. The age cohorts with the largest numbers within them were for those aged between 10 and 14 (3,053) and 5-9 (2,733).

In the same Shaping the Future initiative survey and in response to the question ‘where will you most likely be living in 5 years?’ the % answers were as follows:

45% Anglesey;

30% North Wales;

4% Wales;

11% UK; and

10% don’t know.


There is no specific methodology for this type of assessment. In addition, the types of socio-economic effects to be addressed in an Environmental Statement (ES) for decommissioning projects are not specified in the relevant regulations (Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations 1999 (as amended)). Therefore, it is considered that the methodology used in the 2008 ES remains valid.


Cumulative impacts within the 2008 ES refer to Anglesey Aluminium Metal Limited (AAM). On 30 September 2009 AAM ceased smelting operations due to not being able to source a commercially viable power contract. Therefore it is considered unlikely that cumulative impacts on employment


would arise as reported in the 2008 ES as the decommissioning of Wylfa is not anticipated until 2015 – five years after the closure of AAM.

It is now considered that the main source of cumulative impacts would be in relation to the construction and operation of the proposed new nuclear power station at Wylfa (this was not addressed in the 2008 ES) as there would be an overlap between the two projects. With both projects taking place in tandem (in the future) the overall loss in jobs from decommissioning Wylfa is not likely to be as significant on the local economy as reported in the 2008 ES. In fact impacts on the Anglesey’s local economy are likely to be beneficial due to the number of staff required to construct and ultimately operate the proposed new nuclear power station at Wylfa. However, given that little information is currently known about the proposed new nuclear power station, no more can be said at this stage about its potential cumulative impacts with the decommissioning of Wylfa.

Beneficial cumulative impacts on socio-economic interests are also likely to arise with the construction / operation of the developments associated with the Anglesey Energy Island Programme, these being:

A large offshore wind power development in the Irish Sea to the north of Anglesey;

A biomass-burning combined heat and power plant at the site of the former Anglesey Aluminium plant, proposed by Lateral Power; and

A marine tidal turbine array between Carmel Head and The Skerries, proposed by Marine Current Turbines.

In addition, the following large scale infrastructure developments are also likely to bring about further beneficial cumulative impacts on Anglesey’s economic baseline:

An upgrade of the high-voltage power lines within and leading off Anglesey by National Grid;

An accommodation development in Holyhead proposed by Land and Lakes for construction workers as part of the proposed new nuclear power station at Wylfa (to be reused as a holiday destination after completion of the proposed new nuclear power station);

An upgrade to the Port of Holyhead, proposed by Stena Line, in part to support construction of the Celtic Array offshore wind power development.


Since the preparation of the 2008 ES, the baseline economic conditions have changed slightly for the Isle of Anglesey (see above). In addition, employment levels and expenditure at Wylfa have also changed slightly (see above). A qualitative review has therefore been undertaken of the impacts recorded within the 2008 ES, a summary of which is provided below.

Impacts During Care and Maintenance Preparations Due to Loss of Permanent Employment at Site and Contractors at Site without Mitigation

Impacts on employment (within the study area and within North Anglesey) would be of a slightly lesser extent than that predicted within the 2008 ES, as rather than a loss of 750 permanent and contractor staff there would be a loss of 689 (589 staff and 100 contractors). In addition, baseline economic activity levels within Anglesey have also improved slightly from the figures presented in the 2008 ES. However, Major significant impacts are still anticipated.

It is anticipated that impacts on indirect employment would be slightly worse than that predicted in the 2008 ES, as expenditure in the area has increased from £2.2m in 2005 to £3.2m in 2011/12. However, this increase over the last 6 / 7 years in expenditure is unlikely to change the predicted not significant impact on Anglesey’s economy presented in the 2008 ES.

Impacts on unemployment (within Anglesey and within North Anglesey) would be of a similar extent to those presented within the 2008 ES. This is because fewer people are now employed


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(staff and contractors) at Wylfa than in 2008 (i.e. 689 rather than 750) and unemployment rates on Anglesey and Anglesey North are higher than those recorded in 2008. Therefore impacts would remain Major Adverse (short term).

Impacts on expenditure on Anglesey would be of a similar extent to those presented within the 2008 ES. Although staff expenditure may be slightly different due to a reduced workforce at Wylfa and local purchasing expenditure has increased since 2008 this is unlikely to change the previously recorded not significant impact.

Impacts on population within the 2008 ES were predicted to be Slight and not significant. These impacts are not considered to change significantly as whilst the population of Anglesey has increased from 68,900 in 2006 (from the 2008 ES) to 69,751 in 2011 staff numbers have reduced at the site since 2008 – both these factors would reduce impacts on population.

Negligible (and not significant) impacts on housing demand as recorded in the 2008 ES would not change, as total (staff plus contractor) numbers at Wylfa have reduced from 750 to 689, which would further reduce impacts on housing demand. In addition, the number of houses recorded in Anglesey has increased from 31,702 (2006 figures recorded in the 2008 ES) to 33,944 in 2011, which would further dilute the predicted impacts presented in the 2008 ES.

No significant impacts were predicted on the demand for local services in the 2008 ES, as there would be a long-term reduction in demand for services due to out-migration of c.241 people from study area. However, as fewer people would be out of employment at the end of the care and maintenance preparations phase, any impacts would be reduced.

Predicted beneficial impacts presented within the 2008 ES during the care and maintenance preparations phase due to additional temporary contractors would not change. Although baseline conditions with regard to economic activity and unemployment may have changed since 2008, an influx of contactors into the local area would benefit the local economy regardless of the current baseline figures.

Impacts During Care and Maintenance Preparations Due to Loss of Permanent Employment at Site and Contractors at Site with Mitigation

Since the submission of the 2008 ES, there is now greater potential to reduce the significance of impacts predicted on the local economy with regards to the redeployment of staff within the Magnox organisation, other large-scale developments within Anglesey and the proposed new nuclear power station at Wylfa. As stated above, potential joint mitigation between Wylfa decommissioning and the proposed new nuclear power station would be considered once plans for the proposed new nuclear power station are better defined.

Predicted Impacts During Care and Maintenance and During Final Site Clearance

Impacts predicted within the 2008 ES during the care and maintenance phase and the Final Site Clearance phase would not change. This is because a low number of staff is still anticipated to be employed during the care and maintenance phase (e.g. no more than 20 plus security personnel) (therefore impacts would remain Negligible and not significant) and during the Final Site Clearance phase it is still not possible to predict with any degree of certainty or confidence what economic conditions may prevail over the next 80 to 100 years (although an influx of workers would still lead to a beneficial effect on the local economy regardless of baseline conditions).


It is considered that mitigation measures referenced in the 2008 ES remain valid.

Given that details of the timing and composition of the workforce for the proposed new nuclear power station at Wylfa are currently unknown, quantifying and determining the significance of the combined effects of Wylfa and the proposed new nuclear power station is not practical at this time. Notwithstanding, IoACC has requested consideration of the effects and possible mitigation measures of:


The workforce transition from Wylfa to the proposed new nuclear power station, including up-skilling, retraining etc. to prevent out-migration of local skills;

The impacts and proposed mitigation on tourism and other sectors on the Island;

The impacts and proposed mitigation for the Welsh language;

Impact on housing and accommodation, taking into account the workforce of the proposed new nuclear power station at Wylfa (both during construction and operation); and

The co-ordination between the cumulative impact and mitigation of the decommissioning of Wylfa and adjacent developments.

The following represents possible mitigation measures which could be employed: Magnox would make every effort to re-deploy affected staff and support staff in re-

training or re-skilling for decommissioning roles, in addition to retraining for new roles within the proposed new nuclear power station at Wylfa (if feasible) and other industries on Anglesey;

Preparing a joint Traffic Management Plan with the owners of the proposed new nuclear power station at Wylfa (i.e. minimise effects on the Island’s tourism sector);

Potentially inputting into a Welsh Language Impact Assessment prepared by the owners of the proposed new nuclear power station at Wylfa; and

The co-ordination and joint working between Magnox and other developers on Anglesey i.e. including the owners of the proposed new nuclear power station at Wylfa, would be pursued where socio-economic gains could be secured. As stated in the 2012 Pre-application Opinion Scoping Report, potential joint mitigation between Wylfa and the proposed new nuclear power station will be firmed up in future updates and reviews of the site’s Environmental Management Plans and once plans for the proposed new nuclear power station are better defined.

It should be noted that impacts on housing and accommodation were not seen as a significant issue with regard to the decommissioning of Wylfa, however, it is assumed that this issue would be comprehensively assessed within the ES for the proposed new nuclear power station at Wylfa.

19.4. Conclusions

It is considered that mitigation measures referenced in the 2008 ES remain valid.

Given that details of the timing and composition of the workforce for the proposed new nuclear power station at Wylfa are currently unknown, quantifying and determining the significance of the combined effects of Wylfa and the proposed new nuclear power station is not practical at this time. However, it is possible at this time to state the possible mitigation measures which could be employed in relation to nuclear new-build:

Magnox will make every effort to re-deploy affected staff and support staff in re-training or re-skilling for decommissioning roles, in addition to retraining for new roles within the proposed new nuclear power station at Wylfa (if feasible) and other industries on Anglesey;


Potentially inputting into a Welsh Language Impact Assessment prepared by the owners of the proposed new nuclear power station at Wylfa; and

The co-ordination and joint working between Magnox and other developers on Anglesey i.e. including the owners of the proposed new nuclear power station at Wylfa,


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will be pursued where socio-economic gains could be secured.


20. SURFACE WATERS

The surface waters assessment primarily addressed:

The removal of off shore structures;

Impacts on surface water quality from changes in the non-radioactive content of routine discharges from the site;

Changes in the non-radioactive content of routine discharges of operational effluents associated with decommissioning;

The potential release of turbid and/or contaminated water (e.g. via storm drains) due to decommissioning activities on site;

Changes in the risk of on- or off-site flooding as a result of decommissioning (e.g. due to changes made to storm drains, construction of new buildings or hardstandings or removal of existing buildings or hardstandings);

Impacts to water quality in bathing areas;

Changes to the site’s runoff characteristics;

The non-radioactive content of discharges of operational effluents authorised under the environmental permitting regulations 2010;

Radioactive discharges;

Sediments released due to movements of HGVs and heavy plant;

Changes to coastal erosion processes caused by the cessation of cooling water discharges;

Flood risk; and

Impacts relating to potential spills and leaks of radioactive and non-radioactive substances to nearby waterbodies.



For this topic the significance of an impact was determined on the basis of whether:

There would be a change in compliance with specified short term environmental assessment levels or environmental quality standards; or

There would be an increase or decrease in the number of discharge permits required; or

An existing discharge permit would be breached; or

There would be a requirement for remediation; or

Restrictions on surface water use would have to be introduced.


Pathways exist that could cause impacts to the terrestrial and coastal surface waters in proximity to Wylfa power station during the decommissioning process. During Care and Maintenance Preparations and Final Site Clearance activities such as demolition, excavation, soil handling, construction and the movement of plant/traffic have the potential for releasing sediments to terrestrial and coastal waters. Mitigation has been proposed in line with the EA’s Pollution Prevention Guidance PPG series which will minimise the magnitude of these impacts so that there will not be any significant impacts on surface waters arising from the decommissioning process.


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The potential impact of spills and leaks of non-radioactive substances on the terrestrial and coastal surface water environments has been assessed for the three phases of decommissioning. The coastal waters are considered to be at greater risk due to their closer proximity and linkage via the existing drainage systems. In the absence of mitigation the impacts relating to minor spills and leaks on the coastal environment could result in a Moderate impact, based on the fact it could cause a change to Environmental Quality Standards (EQS) or Environmental Assessment Level (EAL) compliance. The impact has been assessed as potentially significant due to the proximity of bathing waters at Cemaes Bay and Cemlyn Bay. There are two terrestrial watercourses within 0.5km of the site which may also be at risk from spills or leaks. Any spillages could result in a Moderate Adverse impact on these watercourses due to the fact that it may cause a change to the water quality in terms of General Quality Assessment (GQA) grade as well as EQS and EAL compliance. The impact is considered potentially significant as the existing quality of the water environment is expected to be of high quality. Mitigation measures designed to minimise the risk of spills and leaks have been proposed. With mitigation in place the impacts relating to minor spills and leaks on the surface waters environment will not be significant. Care and Maintenance is a largely quiescent phase. However, at times maintenance works may be carried out. The potential impacts on surface waters of such maintenance works and the mitigation measures required would be the same as those discussed for Care and Maintenance Preparations. Otherwise, the only impacts during this phase would be that Wylfa’s contribution to discharges of treated effluent from the off-site sewage plant will be significantly reduced, causing a Slight but not significant benefit to surface water quality. Although most of the drainage systems on site, including the active drainage system will be decommissioned and sealed prior to entry to Care and Maintenance, a drainage system for the management of surface and storm water will have to be maintained on site throughout the Care and Maintenance phase. If the pre-existing drainage infrastructure is to be retained for this purpose (rather than a new system being built ahead of Care and Maintenance entry) this may result in small but regular discharges to local water bodies of radiological / non-radiological contaminants that may have accumulated in the drainage system throughout the operational and active decommissioning stages of the site’s life. Assay and cleaning of the drainage system prior to Care and Maintenance entry in order to prevent this may be a condition of Care and Maintenance entry. There is a permanent significant beneficial impact following Final Site Clearance due to the end of all site discharges and the complete removal of the need for any discharge permits from the site. Further information on impacts on the surface water environment can be found in Part Two, Section 17 of the original 2008 ES. Coastal Issues

The shoreline around Wylfa is comprised of hard, metamorphosed sedimentary rocks that protrude from the sea. On the flanks of the headland the rocks slope from the shoreline at a relatively shallow angle, whilst the rocky sea cliffs are found at the northern edge of the headland. Cemaes Bay, to the east of Wylfa Head, is a natural bay comprised of shallow cliffs, a natural harbour occupied by a small fishing village and a sandy beach. Cemlyn Bay, to the west of the headland, is considered to be the best example of a saline coastal lagoon in Wales and is designated as a Site of Special Scientific Interest (SSSI), Special Protection Area (SPA) and Special Area of Conservation (SAC). The lagoon is separated from the sea by a shingle bank with a narrow channel at the western end, across which a sluice system was built in the 1930s. Seawater exchange occurs mainly through the sluice and by percolation through the shingle bank, although in extreme storms coinciding with spring tides waves can break over the top of the shingle bank. Two large scale tidal flows operate in the Irish Sea adjacent to Anglesey that flow from the north and south. The flows combine in the vicinity of the Isle of Man which produces an eastward flow along the north of Anglesey, hence sea currents at Wylfa are easterly. The wave climate that


interacts with the shoreline at Wylfa comprises both swell waves, and wind waves that are generated on a local scale. The coastline is exposed to both winds from the south west as well as winds from the north. In addition, swell waves can be formed within the Irish Sea promoted by swell entering from the Atlantic from both the north and the south. There is potential for wind waves to reach a significant height due to the uninterrupted fetch available both from the west and the north. Storm surges are rises in sea level that propagates outwards from an area of very low atmospheric pressure. In the UK surge is defined as a water level that is 0.6m different from the predicted tide levels. Surges of this kind can originate within the Irish Sea and further out in the Atlantic Ocean. These surges can produce water levels higher than ordinary tide levels (positive surge) increasing the possibility and severity of flooding and erosion. Analysis undertaken as part of the Safety Case (flooding) has predicted water levels for the 1 in 10,000 year return period. This analysis takes into account tidal surges and wave action. This suggests that extreme water levels may reach 9.41m Above Ordnance Datum (AOD). Water levels of this kind would affect the cooling water pumphouse, which could force the power station to switch to auxiliary cooling systems, but would not impact any nuclear safety-related plant i.e. the turbine hall, reactor buildings or switch-houses. The existing rates of erosion for Wylfa Head are not known, although it is known that the underlying strata is comprised of very hard, metamorphosed rock with high resistance to erosional attack. Therefore, the expected increase in storm frequency and intensity will likely increase rates of erosion, but the impact of this on the headland and cliffs will not be significant on the timescale of the decommissioning process. Climate change will lead to an increased frequency of storms and will alter the return intervals for given sea levels. Sea level rise, independent of any given changes in storm surge frequency and intensity can be accounted for by simply adding the mean sea level to the sea level associated with any particular return frequency. Mean sea level is expected to rise by between 0.14 m and 0.74 m off the Welsh coast by 2080. Such a change would take the 1:100 year sea level as calculated at Amlwch to between 5.19m AOD and 5.45m AOD depending on the CO2 emission scenario being used. Wave heights are also expected to increase but specific values cannot be assigned to the potential height of waves expected in the future, and predictions are hard to make. Currently the Wylfa power station site is protected from the sea by shallow gradient rock foreshore. At some locations this is topped by a sea wall. Generally the integrity of the rock making up Wylfa Head and cliff sections of the North Anglesey coast is such that additional coastal protection is not required. Due to positioning of the power station and the nature of the geology of the coastline in close proximity to the power station this site is well buffered and protected against the potential risks and threats posed by coastal erosion, flooding and climate change. Even when conservative climate change allowances are introduced it would appear that the power station can be fully decommissioned safely. Further detailed information on coastal issues can be found in Part Two, Appendix 17/1 of the original 2008 ES.


New / revised environmental data The 2008 Environmental Statement (2008 ES) was prepared using 2007 as its ‘baseline year’ and describes the following elements of the ‘Surface Water’ environment: Site topography, climate, Surface Water Features, Site Drainage Systems, Terrestrial and Coastal Water Quality, Bathing Water Quality, Pollution Incidents, Flood Risk and existing permitted discharges and licensed abstractions.


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With regard to terrestrial and coastal water quality presented in the 2008 ES, more recent data available from EA Wales and IoACC. There has also been a significant change in how the quality of rivers, estuaries and coastal waters is monitored, assessed and classified, associated with implementation of the European Water Framework Directive (WFD). The General Quality Assessment Scheme (GQA) that is referenced in the 2008 ES has been superseded by these changes. All waterbodies are currently assessed with regard to the condition of key biological elements such as fish, for concentrations of supporting physico-chemical elements, for example oxygen or ammonia, for concentrations of specific pollutants, for example copper, and for hydro-morphology, with the goal of ‘Good Ecological Status/Good Ecological Potential’.

Assessments have been undertaken for the marine waters off the coastline adjacent to Wylfa, in addition to the Afon Wygyr and its tributary to the south west of Wylfa. The available monitoring data are summarised in Table A 6.

Table A 6: WFD Status of Waterbodies in the Study Area.

Waterbody Name Anglesey North The Skerries Wygyr Unnamed – Wygyr

Catchment

Typology Moderately

exposed, Macro-

tidal

Exposed,

Macro-tidal

Low, Small,

Siliceous

Low, Small,

Siliceous

Current Ecological

Quality

Good Status Good Status Good Status Moderate Status

Current Chemical

Quality

Good Does not require

assessment

Does not require

assessment

Does not require

assessment

Hydro-morphological

Quality

High High High Not High

The data indicates that the waterbodies within the study area are of overall good quality.

With regard to bathing water quality, data from three monitoring sites is reported in the 2008 ES, Cemaes Bay,Traeth Bach, Cemlyn Bay. More recent data has been collected and is summarised below. Since 2012, bathing water samples have been analysed for E. Coli and Intestinal Enterococci, in preparation for the forthcoming revised Bathing Waters Directive. Prior to this, samples were analysed for Total coliforms, Faecal coliforms and Faecal streptococci. Bathing Water Quality Sampling Results 2009 – 2012 are shown in Table A 7.

Table A 7: Bathing Water Quality Sampling Results 2009 – 2012.

Bathing Water 2012 2011 2010 2009

Cemaes Bay Minimum Higher* Minimum Minimum

Traeth Bach Minimum Higher Minimum Minimum

Cemlyn Bay Higher Higher Higher Higher

*Higher - bathing water meets the stricter Directive standards. Minimum - bathing water meets the mandatory Directive standards

The Green Coast Award has also been achieved by both Cemlyn Bay and Traeth Bach in 2012.

More recent data (February 2008 to April 2012) from EA Wales’s offshore monitoring point at Middle Mouse (approximately 3.75km to the north-east of Wylfa), has also been collected.


Descriptions of the five EA Wales permitted discharges are reported in the 2008 ES. Since 2007, changes have been made to the limits attached to two of the permits (CG0336501 and CG0336503), with limits relating to Total Hydrocarbons and Oil/Grease being removed. The Wylfa Annual Environmental Report (2010) states that independent monitoring has confirmed that these discharges have been in accordance with the regulatory requirements. There have been no reportable events and all discharges have been within specified limits. EA Wales has also supplied records of cooling water discharge sampling results (January 2008 to December 2012) and these data also confirm that discharges have been in compliance with the permit. With regard to radioactive discharges the Wylfa Annual Environmental Report (2010) states that discharges of both tritium and ‘other’ activity have generally declined over the past few years, coinciding with improvements to water chemistry control processes and equipment, which ultimately limit the quantity of moisture entering the reactor circuit through boiler leaks. Current discharges are small and represent less than 40% of the current discharge limit. Since 2007, there are no updates to report with regard to topography, climate, the descriptions provided of the general characteristics of the surface water features within the study area, pollution incidents, flood risk, licensed abstractions and off site discharge permits.

It is understood that all site drainage systems are still operational and subject to routine maintenance, therefore the description provided in the 2008 ES is considered to remain current.


The 2008 ES states that there is no widely accepted and consistent best practice guidance on environmental impact assessment methodology for impacts on the surface water environment, with use made of guidance within the Department of Transport’s Design Manual for Roads and Bridges (DMRB) where applicable.

This remains to be the case. There has been an update to the DMRB in 2009 and a paper ‘Practical Methodology for Determining the Significance of Impacts on the Water Environment’ (Mustow; Burgess & Walker, 2007) provides further guidance and examples of assessment criteria appropriate to the water environment, but all are based on the approach that has been adopted in the 2008 ES, whereby the significance of the impact on a receptor is a function of the magnitude of an impact and the sensitivity of the receptor. The assessment methodology presented in the 2008 ES is therefore considered to remain relevant and appropriate.


The proposed mitigation measures outlined in the 2008 ES are considered still relevant and appropriate in line with current best practice.


It is considered that there is one new proposed development that has the potential to result in cumulative impacts on the surface water environment, namely the proposed new nuclear power station at Wylfa. This large scale development, is to be located on land that also drains the Afon Wygyr and the coastal waters adjacent to Wylfa. As the sites are both located within the same watershed there is potential for cumulative impacts of a higher magnitude/significance on terrestrial and marine water quality, catchment hydrology (infiltration and rainfall runoff patterns and rates) and pluvial flood risk. Little detailed information is currently available regarding the proposed new nuclear power station at Wylfa. However, it is considered that the potential for adverse cumulative impacts could be mitigated by the implementation of appropriate environmental management measures e.g. drainage management plans, and through the adoption of environmental best practice working methods.

There is also the potential to implement water quality monitoring schemes (for example, visual inspections, spot sampling) during appropriate stages of the two projects with the aim of verifying the effectiveness of the mitigation measures that are put in place.


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Updates to baseline data are available (see above), but the new data corroborates the 2008 ES assessment of the sensitivity of the water environment within the study area. As a result there is no requirement for revision of the magnitude or overall significance of the predicted impacts. No new impacts are anticipated as a result of the revised timeline.

20.3. Conclusions

Updates to baseline data have been assessed, but the new data corroborates the 2008 ES assessment. The proposed mitigation measures outlined in the 2008 ES are considered still relevant and appropriate in line with current best practice.


21. TRAFFIC AND TRANSPORT

Matters Considered

The traffic and transport assessment considered the impact of traffic associated with the decommissioning project at Wylfa on the operation of the highways, road safety and the local ‘environment’, including the experience of or difficulties encountered by other road users and pedestrians (excluding the noise/vibration and emissions effects of traffic which were considered separately under the topics of noise and vibration and air quality respectively). The traffic impacts were assessed through consideration of the percentage changes in total vehicle numbers and, separately, in HGV numbers. Other factors considered included the operational capacity of the roads, recent accident records, the presence of vulnerable road users and of residential properties, schools, hospitals etc. Predictions of future background traffic growth were taken into account.



The significance of impacts, particularly environmental impacts (e.g. severance, pedestrian amenity, fear and intimidation as a result of the proximity of vehicles to pedestrians, and visual impacts), are all, to a degree subjective. Determination of significance is therefore based on expert judgement taking into account a number of factors relating to the sensitivity of the receiving environment, as well as impact magnitude. In this context, sensitive receptors are land uses which will generate a high number of vulnerable road users (i.e. significant housing, schools or hospitals). Project Impacts and Mitigation Measures Identified in the 2008 ES

Changes in personnel numbers at Wylfa will mean that traffic levels associated with the site will change following the end of electricity generation. The numbers (and type) of personnel will change to reflect the different activities being undertaken on the site. A few years after shutdown, not all of the current contingency of permanent staff will be required but additional contractors will be employed for the new construction- and demolition-type work being carried out. During the Care and Maintenance phase of the decommissioning process, the total level of traffic generated by Wylfa Power Station is predicted to be slightly lower than during the baseline year 2007 and the number of HGVs is likely to increase. The traffic environmental impact assessment identified that the A5025 both north and south of the power station will both experience a significant adverse safety impact due to the decommissioning process in 2015. The A5025 south of the station will experience a key significant environmental impact (environmental impacts can include severance, pedestrian amenity, fear and intimidation as a result of the proximity of vehicles to pedestrians and visual impacts). No specific mitigation is proposed because the total traffic levels on these roads are predicted to be at a similar level or lower than those in 2007. In the case of the A5025, although a Moderate impact magnitude has been identified for a short period of time, the total change on these routes is 280 and 306 vehicles to the north and south respectively and these will be spread throughout the working day. The routes benefit from accident records below the national averages, therefore it is not considered necessary to implement specific mitigation measures on these roads. Although in terms of environmental impacts the flow changes on the A5025 to the south are predicted to be Slight Adverse, due to the low number of existing HGV movements an additional 38 HGVs being routed along this link on a daily basis result in a key significant impact. Due to the existing standard of the road and that the route benefits from accident records at or below the national average, and the changes in flows being so low, it is not considered necessary to implement specific mitigation measures on this road in order to accommodate an additional 38 HGV movements.


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Although specific measures on each of the routes mentioned above are not proposed, a Travel Plan (historically known as a Green Travel Plan) is proposed which will assist to reduce the number of trips generated by the station throughout the decommissioning process and this should reduce the number of vehicle movements during the Care and Maintenance phase. During Care and Maintenance there will be very sporadic and limited quantities of traffic travelling to and from Wylfa power station and traffic levels on the highway network will be lower with the decommissioning process taking place than if decommissioning did not take place, leading to a significant positive impact on the operation and safety of the A5025 north and south of the site. As for the Care and Maintenance Preparations period, during the Final Site Clearance phase the A5025 to the south of the site is expected to incur key significant environmental impacts. For the reasons given above for Care and Maintenance Preparations, a Travel Plan is proposed for Final Site Clearance which will reduce the number of vehicle movements generated by the station. It is not deemed necessary to implement any specific mitigation measures to reduce the impact. The traffic associated with the demolition and construction activity that will arise from the decommissioning process will lead to the increased likelihood of mud on the routes used by HGVs when travelling to and from the site. This has both safety and environmental impacts which, in the absence of mitigation, may be significant. However, if necessary, this will be largely alleviated through wheel washing before the HGVs leave the site. Residual safety and environmental impacts associated with mud are considered not significant. Following Final Site Clearance, there will be no vehicles travelling to and from the Wylfa site. There will be significant beneficial impacts on both A5025 links. No significant environmental impact is expected to occur on any sections of the highway network considered as a result of the decommissioning process. Further information on traffic and transport can be found in Part Two, Section 18 of the original 2008 ES.



This section sets out the updates to the Baseline section of the Traffic and Transport chapter of the 2008 ES. The updates to the Baseline Information required due to the time having moved on from the original assessment are set out in the sub-sections below which accord to the sections of the 2008 ES chapter.

Highway Access

The National Cycle Network (NCN) now has a designated on-road route (Route 566) which passes to the south of Wylfa through Tregale Village and links to Llanfechell and Almwch to the east and Llanfflewyn and NCN Route 5 to the south. With the exception of crossing the A5025 at two points, there are otherwise no changes to the cycle network on the assessed highways. Highway access to Wylfa remains as per the 2008 ES.

Power Station Traffic

Magnox has confirmed that at present Wylfa is continuing to generate electricity and the current staffing level of 689 is less than the figure used in the 2008 ES (750 total). However, to maintain consistency with the previous assessment, it has been assumed that the traffic generations remain the same as per the 2008 ES with Wylfa generating in the region of 1,375 traffic movements per day (two-way total AADT) of which 2.4% are HGVs for routine supplies (so this therefore represents worst case). It is also assumed that each person on site continues to generate 1.83 traffic movements per day as per the 2008 ES.


Traffic Flows on the Highway Network

The 2008 ES assessed the local highway network in four sections:

Section A-B: Power Station Access Road (the access road which provides access to Wylfa only)

Section B-C: Power Station Access Road (also including the access road to the nature reserve)

Section C-D: A5025 North of Wylfa

Section C-E: A5025 South of Wylfa

Traffic data for the 2008 ES was obtained by undertaking Automatic Traffic Counter (ATC) surveys for seven-day periods in March and August 2007 and developing an Annual Average Daily Traffic (AADT) flow to be representative of each section. Given that Wylfa (accessed via sections A-B and B-C) and a small nature reserve (accessed via section B-C only) are the only developments served by highway sections A-B and B-C and activity and staffing levels remain approximately similar at Wylfa (as set out above), it is considered that the traffic data for these sections is still suitable for continued use.

It was considered that the 2007 traffic data for the A5025 (sections C-D and C-E) should be updated to reflect changes in background traffic and HGV volumes which may have occurred during the intervening period. Therefore a comparison of the 2007 traffic data presented in the 2008 ES and existing traffic data sources (from 2011) is provided in Table A 8.

Table A 8 : A comparison of the traffic data presented in the 2008 ES and existing traffic data sources.

AADT Traffic Data (HGV %) Highway

Section

Location of survey

2007 2011 %

Change

Notes

C - D: A5025

North of Power

Station Access

Road

East of junction with

Power Station

Access Road

3,600

(2.2%)

3,030 - 15.8% 2007 AADT data set out in

2008 ES, 2011 AADT data

from permanent counter

maintained for Isle of

Anglesey County Council

(IoACC)

South of junction

with Power Station

Access Road

3,428

(2.6%)

- - 2007 AADT data set out in

2008 ES

C - E: A5025

South of Power

Station Access

Road Llanynghenedl 4,966 5,168

(5.1%)

+4.1% All traffic data from

permanent counter

maintained for IoACC. HGV

proportions from ATC

surveys, Oct – Nov 2011

It should be noted in Table A 8 that the traffic data for section C-D uses two different methods to ascertain the AADT figure. The data for 2007 uses week-long ATC surveys in March and August and then factors to reach an AADT figure (as set out in the 2008 ES). The 2011 data is from a permanent traffic counter (maintained on behalf of IoACC) which is situated at the same location and which recorded data for the whole of 2011 thereby providing a ‘true’ reflection of the AADT. The proportion of HGVs is not available from the permanent counter. HG

VS DO NOT TRAVEL ALONG HERE ANYWAY


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For section C-E, traffic data was not available at the same location as the original 2007 survey. Traffic data has therefore been obtained from a permanent traffic counter (maintained on behalf of IoACC) at Llanynghenedl, to the south of the previous location, with the data being the AADT for the whole of 2007 and 2011 (i.e. a ‘true’ AADT figure). The 2011 HGV proportion at Llanynghenedl is from ATC surveys carried out on behalf of IoACC in October and November 2011. It is recognised that traffic volumes on the A5025 at Llanynghenedl were higher in 2007 compared to the 2007 surveys to the south of the Power Station Access Road. Whilst this means the percentage impact will be less due to higher baseline flows, the location is likely to be more representative of traffic flows for this section of the A5025 as it is considered likely that the A5025 would have increasing volumes of traffic and HGVs when approaching Valley and the junctions with the A5 and A55.

Given the changes in the traffic flows on the A5025 between 2007 and 2011, the total traffic and HGV impacts on the A5025 associated with the decommissioning were recalculated. The Revised 2011 Baseline AADT and HGV Traffic Flows are presented in Table A 9.

Table A 9: Revised 2011 Baseline AADT and HGV Traffic Flows.

Highway Section Location of survey AADT HGV % Source

C - D: A5025 North of

Power Station Access

Road

East of junction with


Road

3,030 - AADT data from

permanent traffic

counter for 2011

C - E: A5025 South of


Road

Llanynghenedl 5,168 5.1% AADT data from

permanent counter for

2011, HGV proportions

from ATC surveys Oct

– Nov 2011

Collisions

The 2008 ES included collision data for the period between June 2002 and May 2007. Given that this data is now over five years old, it is considered that this section needs updating. Personal Injury Collision data has been obtained from IoACC for the period January 2008 to December 2012, the latest five year period available. A comparison of the number of collisions for each section of highway is presented in Table A 10.

Table A 10: Collision data 2007 / 2012 Compared.

June 2002 to May 2007 January 2008 to December 2012 Highway Section

Slight Serious Fatal Total Slight Serious Fatal Total

B-C Power Station Access

Road

- - - - - - - -

C-D A5025 North of Power

Station

4 2 0 6 3 1 0 4

C-E A5025 South of Power

Station

18 2 2 22 11 7 2 20

Collision data for Section A-B and B-C was not available for the review.

Analysis of the collision data above does not indicate any existing issues for pedestrians and cyclists and shows relatively few collisions involving HGVs and vehicles performing overtaking


manoeuvres – collision types which, if there was an existing issue, could occur more frequently if traffic and HGV volumes were increased as a result of the decommissioning. The 2008 ES calculated collision rates along these sections of highway to be below expected levels and overall the collision data shows there to have been a decline in the total number of Personal Injury Collisions on sections C-D and C-E. It is therefore adjudged that the updating of the collision data does not increase the sensitivity of the assessed highway sections.

Public Transport

The public transport provision in the area around Wylfa remains as per the 2008 ES. The assessment therefore remains the same as the 2008 ES.


The methodology used in the 2008 ES is broadly similar to present methodologies when preparing Environmental Statements in that it examines the:

Magnitude of the impact

Duration of the impact

Characteristics of the highway; and

Sensitivity of the highway

Each of these elements is discussed below to identify any updates required.

Magnitude of Impact

Traffic Growth Factors

Since the 2008 ES the magnitude of impact has changed in terms of changes to the baseline traffic flows and some minor revisions to the traffic forecast to be generated by the decommissioning. The magnitude of impact is thus updated in the Revised Impacts section below. To carry out this update it has been necessary to develop new factors to growth the Revised 2011 Baseline Traffic Flows. Traffic data has been ‘growthed’ to future assessment years by using a National Road Traffic Forecasts factored by TEMPRO methodology, similar to that used for the 2008 ES. The factors used to growth traffic in this assessment from the Revised 2011 were 1.038 (2011 – 2015) and 1.165 (2011 – 2030).

Traffic Growth Method

When forecasting future year traffic flows, the 2008 ES uses a methodology which removes all traffic flows connected with Wylfa from the Baseline traffic flows before growthing the residual background flows to the future assessment year. The expected traffic generations from Wylfa are then added as required for the scenario. This methodology is considered to still be robust and has been used when updating the traffic impacts in this assessment.

Vehicle Routing

The vehicle routing methodology set out in paragraphs 18.31 – 18.35 of the 2008 ES is also considered to remain robust.

Duration of the impact

The start dates of the Care and Maintenance Preparations, Care and Maintenance and Final Site Clearance phases are all expected to start in the same years stated in the 2008 ES (i.e. 2015, 2025 and 2116 respectively). The duration of the impacts therefore remains unchanged.


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Characteristics of the Highway

As set out in the section above, there have been some changes in the traffic and HGV volumes since the 2008 ES and the impacts are set out in the Revised Impacts section below. From the baseline section the characteristics of the highway are otherwise mostly unchanged since the 2008 ES.

Sensitivity of the Highway

The 2008 ES determines the sensitivity of the Power Station Access Road (sections A-B and B-C) to be classified as ‘not sensitive’. Owing to the lack of any receptors along these considered sections, it is judged that this level of sensitivity remains the same.

Sections C-D and C-E are both classified as “sensitive to changes in traffic flows due to vulnerable road users” and “sensitive to changes in HGVs>25% due to sensitive receptors on route” (i.e. adjacent residential areas). It is now more common to describe the sensitivity of the highway as either high, medium, low or not sensitive. The receptors along section C-D includes the highway passing through part of Cemaes and past individual residences set back from the highway. The sensitivity of section C-D is thus adjudged to be of ‘medium’ sensitivity. Section C-E also passes through small communities such as Llanfachraeth as well as individual residences and businesses set back from the highway. The sensitivity of Section C-E is thus adjudged to also be of ‘medium’ sensitivity


The mitigation proposed in the 2008 ES remains valid. The following section identifies measures which could supplement them.

To reduce the traffic and transport impacts associated with the decommissioning of Wylfa, it is a Traffic Management Plan will be prepared and agreed with the Highway Authority for the Care and Maintenance Preparations and Final Site Clearance phases. The traffic and HGV generations during the Care and Maintenance phase are relatively low and whilst Travel Plan measures, such as car sharing, will be encouraged, no specific measures are proposed for this phase.

The Traffic Management Plan will set out measures to reduce the impact of HGV movements as set out in in the examples provided in Appendix 18.1 of the 2008 ES. To reduce the impact associated with staff (including contractors, Magnox staff, etc) travelling to and from the site the Traffic Management Plan will contain travel planning measures. Initially this would include measures to encourage staff to car share when travelling to and from the site and providing information on sustainable travel options before developing the measures further following feedback/surveys with staff when decommissioning commences.

A monitoring regime will also be set out to determine the effect of the travel planning measures and monitor overall traffic generations during the decommissioning. This monitoring regime could include surveying staff travelling to the site to find out how they travel and determine what measures may work to achieve modal shift, as well as the introduction of a permanent traffic counter at the site entrance which could monitor the traffic generations during the decommissioning.

The Traffic Management Plan will also be updated if/when the works associated with decommissioning Wylfa coincide with significant neighbouring developments, such as the proposed new nuclear power station at Wylfa. It is considered that although cumulative traffic and transport impacts will be higher, there may be opportunities for significantly reducing the individual impact associated with the decommissioning of Wylfa through a combined Traffic Management Plan.


Measures could include: co-ordinating HGV movements (so that if periods of intense HGV movements are expected for the proposed new nuclear power station at Wylfa then it may be possible to minimise HGV movements for the decommissioning and vice versa), potentially sharing facilities such as the Marine Offloading Facility (MOLF) which may be provided as part of the proposed new nuclear power station at Wylfa, and/or recycling material within the wider site (e.g. using surplus topsoil generated by the proposed new nuclear power station at Wylfa for in-filling on the decommissioned site).

Travel planning opportunities for decommissioning staff travelling to site could also be increased by the presence of the proposed new nuclear power station at Wylfa. This could include having a greater chance of finding a partner to car share to work with and allowing decommissioning workers to also use the accommodation to be provided for the construction workers associated with the proposed new nuclear power station at Wylfa, thereby being able to car share/use shuttle bus services or other travel planning mitigation measures put forward as part of the proposed new nuclear power station at Wylfa.


The overall length of the decommissioning of Wylfa is in excess of 100 years and this assessment can only include significant developments which are known at present, whilst recognising that there are likely to be further significant developments in the future. At present planning applications for Nationally Significant Infrastructure Projects are considered by the Planning Inspectorate which currently (January 2013) has three projects registered around Anglesey. These proposals are set out below:

Proposed New Nuclear Power Station at Wylfa

The proposed new nuclear power station at Wylfa would be located adjacent to Wylfa. At present the traffic and transport impacts associated with the proposed new nuclear power station at Wylfa are not known. Other new-build nuclear power stations elsewhere in the UK expect to have large workforces of several thousand construction workers travelling to site each day and a considerable number of associated HGV movements. It is also unknown what mitigation measures may be developed as part of the proposed new nuclear power station at Wylfa.

As mentioned in the Mitigation section above, it is expected that the presence of the proposed new nuclear power station at Wylfa would provide opportunities to reduce the traffic and HGV impacts associated with decommissioning, and Magnox is committed to working together with the developer of the proposed new nuclear power station at Wylfa to reduce traffic and transport impacts.

However, given the size and proximity of the proposed new nuclear power station at Wylfa, it is likely that the cumulative effects of the decommissioning and the proposed new nuclear power station at Wylfa would have a Major Adverse impact on the highway network, although it is expected that the majority of traffic would be associated with the proposed new nuclear power station at Wylfa.

Offshore Wind

This proposal is for an offshore wind farm in the Irish Sea to the north of Wylfa. The scoping report (July 2012) sets out that construction would be likely to commence in 2017 and thus would coincide with the Care and Maintenance Preparation phase of Wylfa. Although detail is not provided, it is expected that a large proportion of the construction material and the Abnormal Indivisible Loads (AILs) would not use the highway network assessed for the decommissioning of


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Wylfa. It is also expected that construction workers travelling to/from the site would also be unlikely to travel from any port accessed off the A5025. Thus the cumulative effects with the decommissioning of Wylfa are likely to be low, although insufficient detail exists at present to reach any firm conclusions.

National Grid Connection

This proposal by National Grid Electricity Transmission PLC is for the connection of the proposed new nuclear power station at Wylfa and the offshore wind farm proposal to the National Grid. The application for the proposal is expected in 2015 and the proposal is still at an early stage of development, although it is likely the proposal would involve the grid connections from the offshore wind farm making landfall around Wylfa, connecting up with a new connection to the proposed new nuclear power station at Wylfa, and then installing a strengthened transmission system across Anglesey and onto the mainland. The proposed route for the transmission lines has yet to be determined, with a number of options being considered.

It is therefore expected that there will be some cumulative traffic and transport impacts owing to the proximity of the grid connection with the proposed new nuclear power station at Wylfa and the offshore wind farm proposal, although the scale and duration of these impacts are not known at present.

In summary, it is likely that there will be cumulative impacts associated with other proposed developments and the decommissioning of Wylfa. At this stage there are too few details to draw any definite conclusions, although given the scale of the proposals it is expected that the overall effect would be a Major Adverse impact on the assessed highway network, although this would mainly be due to the impact of the other developments.


This section sets out the impacts associated with the decommissioning of Wylfa. To provide a robust assessment, this section assumes that potential mitigation measures associated with the proposed new nuclear power station at Wylfa (e.g. MOLF, wider construction worker travel plan) are not in place and a vehicle trip rate of 1.83 trips per day per worker, as per the 2008 ES.

Power Station Access Road

As set out above, the traffic and HGV volumes using the Power Station Access Road (sections A-B and B-C) are likely to have remained the same as those set out in the 2008 ES and the sensitivity of these highway sections also remains ‘not sensitive’. As set out in the sections above the volumes of traffic and HGVs generated during the decommissioning are also similar or less than those set out in the 2008 ES. The magnitude of the impacts are therefore adjudged to be the same as the 2008 ES – a large increase in the overall volumes of traffic and HGVs but a ‘not sensitive’ highway, with the duration of the effect, characteristics of the highway and sensitivity of the receptors remaining the same. The impact on sections A-B and B-C is therefore assessed to be Negligible and not significant for all phases of the decommissioning.

Section C-D North of Power Station Access Road HGV Access

As for the 2008 ES, it is assumed that all existing and future HGV movements travel to/from the site via section C-E. It is therefore assessed that, in terms of HGV movements, the decommissioning of Wylfa would have no effects on section C-D and thus the impact of HGVs is assessed to be not significant for all phases of the decommissioning.

The change in HGV movements for section C-E and the change in total traffic movements for sections C-D and C-E are examined below for each phase of the decommissioning.


Care and Maintenance Preparations

Magnox has confirmed that the traffic generations associated with decommissioning Wylfa remain as per the 2008 ES – up to 607 members of staff and contractors with the existing pro-rata rate of HGV vehicles plus an additional 24 HGVs per day. The alternative No Decommissioning scenario would also remain as per the 2008 ES and would require 300 members of staff per day at the site with the existing pro-rata rate of HGV vehicles delivering routine supplies. The only change in the impact of the decommissioning is therefore due to the changes in the background traffic levels.

Table A 11 and Table A 12 set out the increase in Total Traffic and HGVs for the decommissioning of Wylfa (i.e. the increase in traffic caused by decommissioning compared to the No Decommissioning scenario). Tables 5 and 6 also set out the percentage increases in total traffic and HGVs that decommissioning would cause for a 2015 Assessment Year using the Traffic Data from the 2011 and 2007 surveys.

Table A 11: Changes in Total Traffic Flows.

2015 No Decommissioning

Scenario - Data from 2011

surveys



surveys)

Highway Section Additional

vehicles due to

decommissioning

AADT % increase due to

decommissioning


decommissioning

C - D A5025

North of Power

Station

280 2,708 10.3 3,525 7.9

C - E A5025

South of Power

Station

306 4,924* 6.2 3,329* 9.2

*The AADT data is collected from different survey points

Table A 12: Changes in HGV Flows.


Scenario – HGV Data from

2011 surveys


Scenario - HGV Data from

2007 surveys)

Highway Section Additional HGVs

due to

decommissioning


decommissioning


decommissioning

C - E A5025

South of Power

Station

38 253* 15.0 74* 50.4

*The AADT data is collected from different survey points

As can be seen from Table A 11 and Table A 12, the percentage changes in total traffic and HGVs using the data from the updated 2011 surveys show the impacts to be either similar or lower than the impacts presented in the 2008 ES when using the 2007 survey data. It is therefore concluded that as the traffic impacts are similar or less for this phase and given that the duration of the impact, characteristics and sensitivity of highway sections C-D and C-E have not significantly changed, there are no reasons to upscale the impact assessed for these highway sections in the 2008 ES.


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Care and Maintenance Phase

The Care and Maintenance Phase is expected to commence in 2025, the same timescale as that set out in the 2008 ES. The 2008 ES outlined that during this phase the only vehicle trips expected were associated with the 20 personnel (Full Time Equivalent) that were likely to be based on site with HGVs providing routine supplies. It is now anticipated that this will be reduced further and that it is possible that the site could be monitored remotely with no-one directly based at the site. The only anticipated vehicle trips would therefore be ad-hoc light vehicle and HGV trips to carry out activities such as monitoring and maintenance.

It is still expected that Intermediate Level Waste (ILW) packages will have to be removed from site around 2045. This may require up to 20 staff to be on site to remove up to 70 packages of ILW, although in reality this is likely to be an over-estimate. The duration of removing this ILW is unconfirmed at present, although a timescale of around two weeks would appear likely. Given the low number of vehicles generated by removing the ILW and the low number of trips to Wylfa during the Care and Maintenance Phase, it is considered that the impact of this phase remains Negligible and not significant. Demolition of the radioactive waste storage facility will occur at some point during Care and Maintenance, and this is assumed to be after 2040. Peak traffic movements 35 HGV movements per day are assumed for demolition (for a short period), but these are not considered significant. All efforts will be made to re-use inert demolition material on-site, though some material will be taken off-site for recycling. Given the uncertainties on the timing of the demolition of this facility a traffic assessment will be carried out prior to the works, in agreement with IOACC.

Final Site Clearance

As per the 2008 ES, it is expected that the Final Site Clearance will commence in 2116. Given the timescales involved, it is likely that there will be considerable changes in the technologies and methods for carrying out the works required to complete this phase and subsequently the baseline surveys, assessment of impacts and mitigation measures will need to be reassessed prior to the commencement of this phase, as proposed in the 2008 ES. At present, it is thought likely that the traffic impacts for this phase will remain as set out in the 2008 ES – a peak of 450 personnel and 35 HGV movements per day. As set out in the 2008 ES, these peak traffic movements (859 vehicles) are still significantly lower than the present traffic generations whilst Wylfa is still generating electricity (1,373 movements). The alternative is again a No Decommissioning scenario where 300 personnel would be required. The only change in the impact of the decommissioning is therefore due to the changes in the background traffic levels.

Table A 13 and Table A 14 set out the increase in Total Traffic and HGVs for the decommissioning of Wylfa (i.e. the increase in traffic caused by decommissioning compared to the No Decommissioning scenario). Tables 7 and 8 also set out the percentage increases in total traffic and HGVs that decommissioning would cause for a 2116 Assessment Year, using the Traffic Data from the 2011 and 2007 surveys. As per the 2008 ES, the data from the 2011 surveys has been growthed to 2030 to provide a proxy for 2115 traffic flows.


Table A 13 Changes in Total Traffic Flows.



surveys



surveys)

Highway Section Additional

vehicles due to

decommissioning


decommissioning


decommissioning

C - D A5025

North of Power

Station

137 3,006 4.6 3,914 3.5

C - E A5025

South of Power

Station

173 5,492 3.2 3,694 4.7

*Please note that the AADT data is collected from different survey points

Table A 14: Changes in HGV Flows.


Scenario – HGV Data from

2011 surveys


Scenario - HGV Data from

2007 surveys)

Highway Section Additional HGVs

due to

decommissioning


decommissioning


decommissioning

C - E A5025

South of Power

Station

41 282 14.5 82 50.5

*Please note that the AADT data is collected from different survey points

As can be seen from the Table A 13 and Table A 14, the percentage changes in total traffic and HGVs using the data from the updated 2011 surveys show the impacts to be either similar or lower than the impacts presented in the 2008 ES when using the 2007 survey data. It is therefore concluded that as the traffic impacts are similar or less for this phase and given that the duration of the impact, characteristics and sensitivity of highway sections C-D and C- E have not significantly changed, there are no reasons to upscale the impact assessed for these highway sections in the 2008 ES.

Residual Impacts Following final Site Impacts

Following the completion of Final Site Clearance, it is still anticipated that there will be no traffic travelling to and from the decommissioned site, as stated in the 2008 ES. The impacts for this phase therefore remain the same as per the 2008 ES.

21.3. Conclusions

The percentage changes in total traffic and HGVs using the data from the updated 2011 surveys show the impacts to be either similar or lower than the impacts presented in the 2008 ES when using the 2007 survey data. However, to reduce the traffic and transport impacts associated with the decommissioning of Wylfa, a Traffic Management Plan will be prepared and agreed with the Highway Authority for the Care and Maintenance Preparations and Final Site Clearance phases. The traffic and HGV generations during the Care and Maintenance phase are relatively low and


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whilst Travel Plan measures, such as car sharing, will be encouraged, no specific measures are proposed for this phase.


22. RESIDUAL IMPACTS

With mitigation measures in place the only key significant adverse environmental impacts identified as a result of the assessment were:

Visual impact on two Area of Outstanding Natural Beauty (AONB) views as a result of dismantling works and recladding and modification works to the reactor building during Care and Maintenance Preparations and demolition works during Final Site Clearance.

With mitigation measures in place the only significant adverse environmental impacts identified as a result of the assessment were:

Visual impacts on local and middle distance views and one open access land view as a result of views of decommissioning works during Care and Maintenance Preparations and Final Site Clearance, with corresponding significant adverse impacts on landscape character;

Potential worst case noise impacts at nearby residential properties during Care and Maintenance Preparations and Final Site Clearance (dependent on working methods and the effectiveness of mitigation);

The permanent long term loss of employment opportunities in the sub area containing the site, known as Anglesey North, that will occur by the end of the Care and Maintenance Preparations, with associated short term impacts on the levels of unemployment; and

Possible impact to local road network due to increase in traffic flows. (With a Traffic Plan proposed as mitigation it is not possible to identify the residual impact following its implementation and therefore at worst the residual impact could be significant).

The significant benefits identified were:

Overwhelmingly beneficial visual impacts to local and middle distance views throughout the area with corresponding benefits to landscape character;

The generation of employment for the immediate cluster of wards for almost a decade during final site clearance;

Impacts on surface water quality due to the end of all site discharges and the complete removal of the need for any discharge permits from the site;

Impacts on soil and groundwater quality from the completion of any remediation of contaminated ground during care and maintenance preparations; and

Following final site clearance there will be no traffic travelling to Wylfa which will be positive in terms of the operation and safety of roads.

As a result of decommissioning the following key significant benefits were identified:

Impacts on soil and groundwater quality from the completion of the remediation of contaminated ground on the basis that all restrictions including monitoring, reporting and regulation would cease, and no further remediation would foreseeably be required; and

Views of the site from sensitive viewpoints such as the Isle of Anglesey Area of Outstanding Natural Beauty following the phased removal of the very substantial mass of the buildings and cessation of station lighting at night.

It is considered that the project to decommission Wylfa Power Station is unlikely to have any key significant or significant effects on the environment in another EEA State.


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23. CONCLUSION OF THE 2013 UPDATE

This report has identified the updates that are required to bring the 2008 ES up to date. This review has identified the need for further surveys, to be appropriately timed during decommissioning, and the need for additional mitigation (or mitigation that is specified in a greater level of detail). These changes have been brought about by changes in legislation and/ or accepted industry best practice. The review has also highlighted mitigation that will require further engagement from regulators, such as the ‘Section 61’ agreement specified to agree noise measurement and mitigation.

In terms of environmental protection, the residual impacts (those that cannot be eliminated by mitigation) identified in the 2008 ES remain valid

The impact of new developments around Wylfa, in particular the proposed new nuclear power station, will need to be assessed as details become available. The mechanism of the EMP will be used to ensure that future surveys, mitigation requirements and revisions (as required by new developments), are reported to the ONR and stakeholders.

Continued engagement with regulators and stakeholders will be an important component of the decommissioning project at Wylfa. As the details of surrounding developments become available, Wylfa will assess likely cumulative impacts and, in combination with regulators and stakeholders, will agree and implement, as appropriate, any required additional mitigation measures to protect the environmental and socio-economic assets of the Isle of Anglesey.



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How Do I Comment on this Document?

If you wish make any comment on this document you should do so in writing to the address below: Wylfa EIADR Project Officer ONR – EIADR Team 4N.1 Redgrave Court Merton Road, Bootle L20 7HS Availability of Environmental Statements

Copies of the all the documents that comprise the Environmental Statement can be obtained from: Document Centre Wylfa Power Station Near Cemaes Isle of Anglesey LL67 0DH The cost of hard copies of these documents is £50. Alternatively, electronic copies are available on CD free of charge from the address above. Copies of the non-technical summary are also available free of charge from the address above or can be viewed on the Magnox website www.magnoxsites.co.uk. Where Can I View the Environmental Statement? Copies can be viewed free of charge at the following locations: Public Libraries

Amlwch Library Lôn Parys Amlwch LL68 9EA Tel (01407) 830145

Beaumaris Library David Hughes Community Centre Beaumaris LL58 8AL Tel (01248) 810659

Bangor Public Library Ffordd Gwynedd Bangor Gwynedd LL57 1DR Tel (01248) 353479

Cemaes Library Glascoed Road Cemaes Village LL67 0HN Tel (01407) 711025

Holyhead Library Newry Fields Holyhead LL65 1LA Tel (01407) 762917

Llangefni Library Lôn y Felin Llangefni LL77 7RT Tel (01248) 752095

Menai Bridge Library Wood Street Menai Bridge LL59 5AS Tel (01248) 712706

Moelfre Library Y Ganolfan Moelfre LL72 8HA Tel (01248) 410331

Caernarfon Library Pavilion Road Caernarfon LL55 1AS Tel (01286) 679463

Rhosneigr Library High Street Rhosneigr LL64 5UX Tel (01407) 811293

http://www.magnoxsites.co.uk/

APPENDIX 1: CHANGES TO THE PROJECT DESCRIPTION 2008 - 2013

2008 Project Description 2013 Revision Effect upon the EIA 1 Landholding – in 2008

the landholding associated with Wylfa was 113ha. The 21ha nuclear licensed site remains unchanged, but the remaining land has now been transferred to Horizon.

As a result of the sale of land by the NDA to Horizon, the landholding associated with the site is now much reduced in comparison with that described in 2008 ES. The area considered by the assessment is now entirely comprised of the nuclear licensed site, which is outlined in red in Figure WYA/GEN/1.

The spatial scope of any of the environmental topic is not affected by the land sale, as the spatial area considered in each of these topics (normally termed the study area) is defined by the relevant methodology, not the land-holding. For example, ecological receptors are defined within a 5km radius (see Figure WYA/EC/1) of the site, and therefore not restricted to the previous site boundary. In any case, any particular survey that focused on the original NDA landholding will cover an area over and above the existing site, and therefore will cover an area sufficient for the scope of the revised assessment. The Decommissioning Project was always due to occur almost entirely within the nuclear licensed site (which remains unchanged) and the only impact that the land sale has been to eliminate the possibility of the site using four potential laydown areas (see Figure WYA/GEN/5) known as: Alternative Laydown Areas 1-3, and Laydown Area 3. The decommissioning team at Wylfa have reviewed the size of the remaining Laydown Areas (1 & 2) which are within the Wylfa Nuclear Licensed Site against laydown areas at other Magnox decommissioning sites and have concluded that these are sufficient for the purposes of decommissioning, and therefore no additional laydown areas are required to be identified.

2 The Information Centre at Wylfa and the Learning and Development Centre.

These are not located on the nuclear licensed site, and both have been transferred to Horizon (though Wylfa retains use of certain areas as part of this agreement). The Learning and Development Centre has now been relocated.

This has no impact upon the EIA.

3 Strategy for the Radioactive Waste Storage Building

There has been a change in strategy for the radioactive waste storage building, in that it will now be demolished as soon as

Earlier demolition will eliminate any ‘asset care’ and monitoring costs associated with the structure. Earlier demolition of this building is not considered to have any impact upon the EIA. For planning purposes the store will be assumed to be emptied at some point after 2040.



2008 Project Description 2013 Revision Effect upon the EIA possible after the contents of the store have been transferred to a geological disposal facility (previously it was to be demolished at Final Site Clearance).

4 ILW generation – in the 2008 ES this was expected to cease at the end of 2010.

ILW will continue to be generated up until the end of generation, which is may be up to the end of 2015.

No effect upon the EIA, as waste increased waste volumes are not considered to have a significant impact on store size.

5 LLW Management – in the 2008 ES disposal at the LLWR in Cumbria

More routes for the disposal and recycling of LLW will be utilised during decommissioning, in line with NDA strategy.

No effect upon the EIA – all LLW will leave the site, though more routes may be utilised.

6 The proposed option for operational ILW described in the 2008 ES was to retrieve the waste from its current storage location, then encapsulate and package in appropriate storage containers.

Retrieved ILW will now be placed directly into Ductile Cast Iron Containers (DCICs) without encapsulation.

No effect upon the EIA – this option means that encapsulation facilities will not be required, so reducing construction requirements, but this is not considered to be a significant change.

Wylfa Power Station

APPENDIX 2: BASELINE ENVIRONMENTAL CHANGE 2008 AND 2012

2008 Baseline summary 2012 Baseline change Air Quality

There are currently no Air Quality Management Areas (AQMAs) on the Isle of Anglesey and none pending.

Background conditions are similar to those presented in 2008. NOx and NO2 concentrations are marginally higher. All concentrations are well below Air Quality Strategy Objectives (See Section 13).

Archaeology There are no Scheduled Ancient Monuments on the power station site. The nearest Scheduled Ancient Monument is a triangular arrangement of Early Bronze age standing stones 2.5km south-west of the site. There are no Listed Buildings within the study area. There are three Listed Buildings 1km south-west of the power station. Cestyll Gardens lies within the NDA landholding and is included in the Cadw/ICOMOS Register of Landscapes, Parks and Gardens of Special Historic Interest in Wales. There are no registered historic battlefields within the study area.

The baseline presented in 2008 in relation to Scheduled Ancient Monuments, Listed Buildings and Cestyll Gardens remain the same. A revised Historic Environment Record (HER) map has been produced (See Section 14).

Ecology The following protected areas are within 5km: Tre’r Gof SSSI. Cemlyn Bay SSSI.Ynys Feurig, Cemlyn Bay and The Skerries Special Protection Area (SPA). Cemlyn Bay Special Area of Conservation (SAC).

The sites listed remain valid. It has been confirmed since 2008 that a pair of choughs (Pyrrhocorax pyrrhocorax) (listed on Schedule 1 of the Wildlife & Countryside Act) have nested within the site. Further baseline surveys for birds are required (See Section 15).



2008 Baseline summary 2012 Baseline change Geology, Hydrogeology and Soils The underlying bedrock is New Harbour Group of the Pre-Cambrian Mona Complex. Wylfa Head and part of the headland to the north-west of the site comprise rocks of the Gwna Group. Within the New Harbour Group there are outcrops of extrusive igneous rock, with one such outcrop cutting across the site to the south of the turbine hall and reactor building. There are no significant aquifers beneath the site. The New Harbour Group is classified as a minor aquifer as it may contain water where it is fractured, weathered or broken. There are no designated geological sites of conservation value on or adjacent to the power station. Henborth Site of Special Scientific Interest (gSSSI) is within 5km.

The 2008 baseline remains valid, but has been updated by specific studies relating to groundwater quality, local sources of contamination and soils. Specifically, this relates to a sump to the south of the site which has been identified as a source of contaminated from chlorinated solvents (See Section 16).

Landscape and Visual

Essentially rocky shoreline to the north west. Wylfa Head to the north east, a level outcrop with craggy shoreline. Area of scrub and woodland to the south east. Area of flat small scale agricultural fields surrounding the site and vegetated area to the south. Close to the coast the land generally comprises rough grazing with exposed rock and gorse thickets. Farther inland the land comprises gently

While the local landscape environment remains largely the same as in 2008 a number of documents have been published that are relevant to the assessment. These are: Countryside Council for Wales, Wales Tranquil Areas Map, 2009. Anglesey Area of Outstanding Natural Beauty Management Plan, 2009-

2014. Countryside Council for Wales – LANDMAP 2008. Isle of Anglesey County Council , Landscape Strategy update 2011. Countryside Council for Wales Draft Regional Landscape Character.* Countryside Council for Wales Regional Seascape Assessment for Wales

2009.

Wylfa Power Station

2008 Baseline summary 2012 Baseline change undulating, low lying farmland and isolated woodland.

Countryside Council for Wales – Open Access Land Maps http://www.ccw.gov.uk/interactive-maps/outdoor-wales-online-map/open-access-land/open-access-maps.aspx?_dmr=2&_dms=dra&_dmc=SH370930.

Noise and Vibration Because of a significant change in receptors (as a result of demolition or dis-repair), the current status each of the 2008 receptors is listed below and its status described.

Cafnan is still an occupied building and farm (used for noise and dust monitoring by IoACC), although it is currently in a poor state of repair; Pont Cafnan is still standing as a building, although it is currently in a poor state of repair; Cestyll is still standing although it is currently in a poor state of repair; Pennant is still standing although it is currently in a poor state of repair, with most entrances blocked up and a reinforced gateway in place; Tan yr Allt is confirmed as still standing, although it is currently in a poor state of repair, with most entrances blocked up and a reinforced gateway

in place; The Firs is confirmed as still standing, although it is currently in a poor state of repair, with most entrances blocked up and a reinforced gateway

in place; Tregele Village, no change; Pen Lon has been demolished ; Pentregof is still standing as a building ; Cemaes Village, no change; Simdda Wen has been demolished ; Ty Croes is confirmed as still standing, although it is currently in a poor state of repair, with most entrances blocked up and a reinforced gateway

in place; and Haul a Gwynt is confirmed as still standing, although it is currently in a poor state of repair, with most entrances blocked up and a reinforced

gateway in place. Socio-Economic It is recognised that the socio-economic baseline has changed. This is described in full in Section 19. Surface Waters The main surface water feature in the area with the potential to be directly affected by the site is the coastal water of the Irish Sea. It is from here that

The identified water bodies remain as described, however revised water quality designations have been introduced. These are described in Section 20.


http://www.ccw.gov.uk/interactive-maps/outdoor-wales-online-map/open-access-land/open-access-maps.aspx?_dmr=2&_dms=dra&_dmc=SH370930




2008 Baseline summary 2012 Baseline change water is taken for use on the site prior to being discharged back to the sea. There are no significant surface fresh water courses at or within the immediate area to the Wylfa site and as such there are no water quality designations. The nearest major fresh water course is the Afon Wygyr which drains land to the east of the power station and flows into the Irish Sea at Cemaes Bay some 2km from the power station. There is a small intermittent stream to the south of the site, which draws on shallow water within the superficial deposits. There are also a number of small springs and drainage ditches feeding Tre’r Gof SSSI located to the north-east of the station. Traffic and Transport The main vehicular route to and from Wylfa power station site is the A5025 which connects the site to the A5 at Valley and the A55, approximately 20km to the south. To the east, the A5025 connects the power station to Cemaes Village and a number of other settlements on the northern and eastern coast of Anglesey. In both directions this route is predominantly rural in nature but also runs via a number of settlements.

While the road network remains as described opposite, the baseline traffic data has been revised (Section 21).

Wylfa Power Station

APPENDIX 3: SUMMARY OF SIGNIFICANT ADVERSE IMPACTS 2008 - 2013

Wylfa Power Station

Impact 2008 Revised impact assessment 2013 Air Quality

The impact of dust on residential properties from soiled vehicles or vehicles carrying potentially dusty loads. The impact of dust on residential properties, industrial receptors, and public areas (due to routine on-site decommissioning activities e.g. construction, demolition and the handling of waste/materials) has not been assessed as significant or key significant, however the mitigation measures opposite will be used, as appropriate, as measures of best practice.

No change in impacts. Provided that other developments (such as the proposed new nuclear power station at Wylfa) adopt suitable best practice mitigation measures, such as those outlined in the 2008 ES, the potential cumulative impact from fugitive dust emissions during the decommissioning phase will remain as predicted within the 2008 ES

Archaeology Certain features of the historic landscape have the potential to have survived the disturbance of construction within the immediate vicinity of the power station, in the area of car-parking and overflow car-parking between Porth y Pistyll and Porth y Gwartheg and in the vicinity of the outflow at Porth Wnal and within the wider curtilage of the NDA land holding.

In addition to those listed opposite, it has been identified that the complete removal of Wylfa will cause a Major Adverse impact, in terms of the loss of an industrial archaeological asset. The adverse cumulative impact of the proposed new nuclear power station at Wylfa will balance out the beneficial impacts of decommissioning of Wylfa upon the Listed Buildings and Historic Landscape, leading to a neutral impact upon these cultural heritage assets. However, during the proposed Care and Maintenance period and construction period for the proposed new nuclear power station as Wylfa, there would be a cumulative Slight Adverse impact effect upon the setting of these assets. However, this effect is not considered to be significant. There is no potential for cumulative impacts upon the below ground archaeological remains as the proposed decommissioning works are not impacting this resource



Impact 2008 Revised impact assessment 2013 Ecology Disturbance to or loss of small amounts of coastal cliff grassland and strandline vegetation by use of Laydown Areas 1 and 2. Loss of or disturbance to habitat of moderate botanical interest in Laydown Area 2. Disruption of the adjacent cliff habitat complexes by fragmentation of the coastal wildlife corridor due to extension of Laydown Area 1 on to the cliff. Potential degradation of species-rich vegetation on the AONB and Heritage Coast and in the Tre’r Gof SSSI caused by deposition of dust generated from demolition activities on site. Accidental killing of adders during demolition of the towns water tank. Disturbance to bird species from construction of a coffer dam, demolition of the outfall gatehouse complex and explosive demolition of the offshore structures. Loss of habitat and increased disturbance could cause severe disruption to the gull colony in Laydown Area 1. Potential loss of habitat and or buildings could impact breeding birds. The loss of Building 99 which supports a roost of common pipistrelle bats and the loss of other buildings with moderate or high potential to support roosting bats and subsequent loss of potential and actual roost sites. Disturbance to foraging bats from light spill. Disturbance to cetaceans and grey seals from explosive demolition of the CW jetty and offshore structures.

The impacts outlined within the 2008 ES are considered to remain valid. In addition to those impacts, it is predicted that a Moderate Adverse impact on breeding choughs (a receptor of ‘regional importance’) will occur as a result of loss of nesting sites and noise and visual disturbance. In terms of potential future cumulative impacts from nuclear new-build, disturbance-related effects from increased noise and lighting are likely to be greater and continue for longer. This could have an adverse cumulative impact on bats and birds in particular. The construction of the proposed new nuclear power station at Wylfa would also result in habitat loss that would further reduce the availability of foraging resources for the ecological receptors associated with the decommissioning of Wylfa, and therefore result in increased displacement of such receptors

Geology, Hydrogeology and Soils

Wylfa Power Station


Impact 2008 Revised impact assessment 2013 Changes in soil and/or groundwater quality due to creation of new contaminant pathways (e.g. due to the creation of boreholes, piles or excavations connecting previously unconnected geological strata). Changes in soil and/or groundwater quality due to spills or leaks of non-radioactive substances. Changes in soil and/or groundwater quality due to inadvertent contamination of soils and/or groundwater arising from inappropriate use of contaminated soils, wastes or materials as in-fill. Changes in soil and/or groundwater quality due to inadvertent or uncontrolled disturbance or spreading of existing contaminated soils, including movement by windblown dust, attachment to vehicles, entrainment in runoff and inappropriate soil storage/handling operations. Changes in soil and/or groundwater quality due to inadvertent contamination of soils and/or groundwater arising from temporary storage of contaminated soils, wastes or materials. Changes in groundwater quality and/or flow caused by inadvertent effects on groundwater level, flow and quality due to the in-fill of deep basements and the breaching of basement structures to prevent ponding. Changes in groundwater quality and/or levels and flow due to mobilisation of existing contamination caused by changes in water table levels and consequential changes to groundwater flow regime. The degradation of construction materials due to high levels of sulphate in soil or groundwater / Aggressive Chemical Environment for Concrete (ACEC).

The following additional impacts, over and above those presented in the 2008 ES have been identified as follows: The impact of the structures on site as a contaminant source. Possibly – (dependent on timelines) the cumulative impact on Soils and

Groundwater flow and quality and to the SSSI site from the proposed Horizon site.

The impact of inadvertent effects of dewatering on groundwater resources and nearby abstractions, watercourse and sites of Conservational interest including the risk of mobilisation of contaminants into the area.

Cumulative impacts likely to arise from nuclear new-build are as follows:

Disturbance and mobilisation of contaminants in soils; and

Disruption of groundwater interfaces.

Landscape and Visual

Wylfa Power Station


Impact 2008 Revised impact assessment 2013 Impacts on local views. No change in impacts.

Is likely that the construction and operation of the proposed new nuclear power station at Wylfa will reverse the beneficial effects identified in the 2008 ES and in some cases there will be the potential for significant cumulative adverse effects as a result, particularly if the proposed new nuclear power station at Wylfa results in changes to the woodland and artificial drumlin landscape designed by Dame Sylvia Crowe as mitigation associated with Wylfa. It is understood this designed landscape is in the process of being reviewed by Cadw in terms of it being included in the register of landscapes, parks and gardens of historic interest in Wales.

Noise and Vibration General changes to noise levels directly from the site and associated changes in traffic.

No change in impacts, however, in line with current best practice, contractors will prepare method statements to allow an accurate prediction of noise impacts (and thus ensure appropriate mitigation measures are in place).

Socio-Economic Employment opportunities and unemployment level in study area. While the summary conclusion remains valid, since the preparation of the 2008

ES, the baseline economic conditions have changed slightly for the Isle of Anglesey and detailed impacts have been re-assessed (See Section 19). Cumulative impacts in relation to the construction and operation of the proposed new nuclear power station at Wylfa could mean that the overall loss in jobs from decommissioning Wylfa is not likely to be as significant on the local economy as reported in the 2008 ES.

Surface Waters Changes in terrestrial and coastal water quality due to release of sediment laden run off from construction, demolition and traffic movements. Changes in terrestrial and coastal water quality due to minor spills or leaks of non-radioactive substances.

No change to the impact assessment. It is considered that the proposed new nuclear power station at Wylfa has the potential to result in cumulative impacts on the surface water environment. . This large scale development is to be located on land that also drains the Afon Wygyr and the coastal waters adjacent to Wylfa. As the sites are both located within the same watershed there is potential for cumulative impacts of a higher

Wylfa Power Station


Impact 2008 Revised impact assessment 2013 magnitude/significance on terrestrial and marine water quality, catchment hydrology (infiltration and rainfall runoff patterns and rates) and pluvial flood risk.

Traffic and Transport Impacts on operation and safety and environment of A5025. Impacts on safety etc. due to mud on roads.

No change to impacts.

Wylfa Power Station

APPENDIX 4: MITIGATION MEASURES 2008 - 2013

Mitigation 2008 Revised mitigation 2013 Air Quality

Ensuring that dusty materials are transported appropriately (e.g. sheeting of vehicles carrying spoil and other dusty materials); Regular cleaning of the site entrance; and Provision of wheel and vehicle body washing as appropriate. Use of water sprays during external demolition activities as appropriate. Use of water sprays during outside in-fill operations as appropriate. Avoidance of vehicular use on un-surfaced ground where possible and limits on vehicle speeds on such surfaces where it cannot be avoided. On-site roads to be regularly cleaned of mud/dust deposits and sheeting of vehicles carrying potentially dusty loads, as appropriate and as far as practicable. Minimisation of dust during particularly windy or dry conditions will be achieved by a variety of activities e.g. the use of water sprays. Minimisation of unnecessary material and waste handling as far as practicable. Use of water sprays to maintain damp surfaces during dry and windy weather. Minimisation of dust from stockpiles will be achieved by a variety of techniques which may include sheeting of surfaces and/or use of wind fences etc as appropriate. Minimisation of dust will be achieved by a variety of techniques which may include the covering of containers and/or use of wind fences as appropriate.

The mitigation measures outlined in the 2008 ES are considered to remain valid, and as such, no updates are considered necessary. However, specific methods will be agreed in consultation with IoACC’s EHO. Examples of more specific dust monitoring methods (timings and equipment) are specified in Section 13.

Archaeology A walkover survey to identify any surface evidence of previous occupation and land use, including agricultural, industrial, maritime and wartime

In addition to the 2008 mitigation, in view of the industrial significance of the Wylfa complex, it will be recorded at an appropriate level before dismantling



Mitigation 2008 Revised mitigation 2013 operations within this area, will be undertaken prior to commencing any decommissioning works which might involve ground disturbance in the vicinity of the power station, in the area of car-parking and overflow car-parking between Porth y Pistyll and Porth y Gwartheg and in the vicinity of the outflow at Porth Wnal and within the wider curtilage of the NDA land holding.

works are undertaken and records relating to its construction and use will be deposited in an appropriate archive. It has been agreed with the RCAHMW that a photographic record prior to and during decommissioning works, supplemented by background information on the history of Wylfa, will constitute an appropriate level of recording. If agreed to be necessary, a Written Scheme of Investigation (WSI) providing detail of the necessary mitigation will be produced and agreed with Gwynedd Archaeological Trust prior to the start of decommissioning.

Ecology Use of a buffer strip in Laydown Area 2 and restricting Laydown Area 1 to within the security fence. Marking off a 2m-wide buffer strip by a fence or a hedge of native species of local provenance to prevent incursion by personnel and vehicles. No part of Laydown Area 1 to extend outside the security fence. Control of dust with standard dust suppression technologies including use of water (see air quality above and Section 10 (Air Quality and Dust). Reptile-proof fencing around work area and removal of reptiles from within. Strimming areas suitable for adders to discourage occupation. Re-instate suitable adder habitat on the footprint of the former towns water tank. Explosive demolition to occur outside of breeding and passage seasons (March – September). Restrict Laydown Area 1 to within the outer security fence. All suitable nesting habitat to be removed outside of the bird breeding season, or if not possible then nest sites to be checked by a qualified ecologist and works to be suspended if birds are breeding. Buildings

In addition to those measures described in the 2008 ES , mitigation for the loss of chough nest sites will be provided. This includes the provision of artificial nest boxes within an area that would not be disturbed by the proposed works. Suitable nest boxes will be provided prior to the commencement of the proposed decommissioning works. In addition, the demolition of any buildings that are used by nesting choughs will be undertaken outside of the bird breeding season (which is between the months of March and August (inclusive)). As a precautionary measure, the mitigation described in the 2008 ES to prevent the incidental mortality of adders will be extended to include all suitable reptile habitat within the site. This will include a targeted reptile survey one year prior to the commencement of the decommissioning works and hand-strimming any suitable vegetation that is present within the site that would be directly affected by the proposed works. If reptiles were found to be present during the pre-decommissioning survey, reptile-proof fencing will be installed around such areas. The implementation of measures that would provide a net gain for biodiversity will be discussed and agreed with CCW. Updated surveys for badgers, otters, water voles, bats and other legally

Wylfa Power Station


Mitigation 2008 Revised mitigation 2013 supporting nesting birds to be demolished outside bird breeding season. All such buildings to be surveyed for roosts approx. 2 years before demolition; mitigation for found roosts to be agreed and licensed by CCW. In buildings where no bats are found, demolition to be carried out under a ‘watching brief’ supervised by a suitably qualified and experienced ecologist. Roosts suitable for summer and winter use to be provided prior to any demolition works commencing, and as agreed by CCW. Demolition under EPS licence guaranteeing safe exclusion and provision of alternative roost site. After-dark working will be minimised and confined to winter; directional lighting will be used. Explosive demolition to occur at low tide. Dedicated observer to ensure that no cetaceans have been seen in the area at least 30 minutes prior to demolition.

protected species will be undertaken one year before the commencement of any decommissioning works that could affect these species. These surveys will be supplemented with on-going monitoring by an Ecological Clerk of Works during active decommissioning works to ensure legislative compliance.

Geology, Hydrogeology and Soils Compliance with British Standard 5930 (Code of Practice for Site Investigations) and BS 10175 (Investigation of Potentially Contaminated Sites – Code of Practice). Compliance with EA Technical Report P5-065/TR (Technical Aspects of Site Investigation). Compliance with relevant PPG guidelines. Use of Made Ground that does not exceed average permeability of in-situ material to avoid groundwater flow issues. Placement of flow barriers and monitoring of level and flow pattern impacts as required. Bunding of chemical and fuel storage according to PPG2 and PPG6 and Oil

In addition to the measure opposite, mitigation will also include: Following guidance contained with PPG 22 – Dealing with Spills.

In relation to sub-surface structures:

Undertake a tiered qualitative risk assessment (QLRA) process to

understand the structures, the condition of the concrete, impact of saline or groundwater interface in order to understand the potential for the release of ions or contamination from surfaces into groundwater.

If adverse impact is identified as possible, undertake detailed geo-environmental risk assessment to inform the decommissioning methodologies and to take into account any site specific contamination

Wylfa Power Station


Mitigation 2008 Revised mitigation 2013 Storage Regulations 2001. Appropriate protocols for chemicals and fuel handling in line with PPG6 and PPG11, with trained staff only to operate facilities. Emergency spill response planning according to PPG21, including spill kits kept on site and trained staff available. Authorised disposal or on site treatment of unsuitable soils, wastes and materials. Sampling and testing of potentially contaminated soils, wastes and materials prior to use as appropriate. Use of Site Waste Management Plans (SWMP). Desk studies and site investigation, monitoring and remediation before works commence in order to determine the presence or absence of contamination, so that appropriate working practices can be adopted from the outset. Controlled access to or from known or potentially contaminated working areas as appropriate. Use of re-circulating wheel washers on HGVs leaving site as appropriate. See mitigation below under ‘Inadvertent contamination of soils and/or groundwater arising from temporary storage of contaminated soils, wastes or materials’. Sampling and testing of soils, wastes and materials prior to storage as appropriate. Use of containment (e.g. membranes) to reduce likelihood of cross-contamination, as appropriate. Management of rainwater run-off from storage areas for contaminated or potentially contaminated soil, wastes and materials. Characterisation of groundwater levels and flow direction prior to the start

and geotechnical constraints. Removal of sub surface tanks and sealing of voids if appropriate (refer

to PPG 27). Alternatives to puncturing may include back-fill with structural low

permeability (e.g. cohesive or stony cohesive fill) and/or assessment of whether “ponding” (e.g. within granular fill) presents a risk situation.

In relation to localised remediation of contaminated ground and/ or groundwater:

EA Rapid Measurement Techniques. EA Model Procedures for the Management of Land Contamination

(CLR11).

In relation to Mobilisation of Existing Contamination by Direct Rainwater Infiltration due to Changes in Ground Cover and the Creation of Temporary Open excavations:

Characterisation of the likely contamination under buildings/ to inform potential sources of contamination.

In relation to dewatering impacts, additional mitigation is:

Undertake a tiered review of local site specific site investigation and hydrogeological information to inform likely effects and required mitigation measures

Wylfa Power Station


Mitigation 2008 Revised mitigation 2013 of decommissioning and sampling and testing of potentially contaminated soils, wastes and materials prior to use as appropriate. Puncture all remaining services and foundations to reduce the likelihood of ponding. Dewatering of affected areas to avoid mobilisation of contaminants. The selection of in-fill materials with appropriate physical and chemical properties. Sulphate testing will be carried out in area where concrete is to be placed. The appropriate grade of concrete will be selected in accordance with BRE Special Digest 1 (Reference 12 in Section 13 of the 2008 ES). Prior to construction of individual scheme elements, detailed geo-environmental investigations will be undertaken in order to inform the construction methodologies and to take into account any site specific contamination and geotechnical constraints. Landscape and Visual

Use of directional lighting. No change, however a Seascape Assessment will be carried out in combination with any new major development at Wylfa.

Noise and Vibration Use of equipment fitted with effective silencers. Designated site contact to whom complaints/queries about construction/demolition activity can be directed – any complaints to be investigated and action taken where appropriate. Local residents informed of exceptional activities. No potentially significant external working outside of normal working hours without prior agreement with the local authority.

Mitigation measures will now be included in the Section 61 Consent Application would typically include the following:

The hours of working will be planned, and account will be taken of the effects of noise upon persons in areas surrounding site operations and upon persons working on site, taking into account the nature of land use in the areas concerned, the duration of work and the likely consequence of any lengthening of work periods.

Where reasonably practicable, quiet working methods will be

Wylfa Power Station


Mitigation 2008 Revised mitigation 2013 Compliance with BS5228. employed, including use of the most suitable plant, reasonable hours

of working for noisy operations, and economy and speed of operations. Site work will be programmed, when appropriate, so that haulage vehicles will not arrive at or leave the site between 1900hrs and 0700hrs.

Noise will be controlled at source and the spread of noise will be limited, through implementation of general measures such as:

Avoiding unnecessary revving of engines and switching off equipment when not required;

Keeping internal haul routes well maintained and avoiding steep gradients;

Using rubber linings in, for example, chutes and dumpers to reduce impact noise;

Minimising drop height of materials; and Starting-up plant and vehicles sequentially rather than all together.

The movement of plant onto and around the site will have regard to the normal operating hours of the site and the location of any sensitive receptor locations as far as is reasonably practicable. The use of conventional audible reversing alarms may cause problems on some sites and alternatives are available. Audible reversing warning systems on mobile plant and vehicles will be of a type which, whilst ensuring that they give proper warning, has a minimum noise impact on persons outside sites. Where practicable, alternative reversing warning systems will be employed to reduce the impact of noise outside sites. A method of noise measurement will be agreed prior to commencement of site works.

Socio-Economic Magnox will make every effort to re-deploy affected staff and support staff in re-training or re-skilling for decommissioning roles.

Additional mitigation has been identified in relation to new nuclear build at Wylfa:

Magnox will make every effort to re-deploy affected staff and support

Wylfa Power Station


Mitigation 2008 Revised mitigation 2013 Magnox will encourage its contractors to make use of local labour, equipment & services wherever possible. During Final Site Clearance there are potential opportunities for training the unemployed to take up opportunities subject to skills needs over the longer term.

staff in re-training or re-skilling for decommissioning roles, in addition to retraining for new roles within the proposed new nuclear power station at Wylfa (if feasible) and other industries on Anglesey;


Inputting into a Welsh Language Impact Assessment prepared by the owners of the proposed new nuclear power station at Wylfa; and

The co-ordination and joint working between Magnox and other developers on Anglesey i.e. including the owners of the proposed new nuclear power station at Wylfa, will be pursued where socio-economic gains could be secured. As stated in the 2012 Pre-application Opinion Scoping Report, potential joint mitigation between Wylfa and the proposed new nuclear power station will be firmed up in future updates and reviews of the site’s Environmental Management Plans and once plans for the proposed new nuclear power station are better defined.

Surface Waters Where necessary:

wetting down to prevent wind blown spread of dust into locations where subsequent washing into surface drains would be likely;

careful design and siting of spoil mounds, this may include the construction of low walls around spoil areas;

sheeting or seeding of long term soil mounds; the use of sediment barriers to contain run off within areas; measures to keep on and off site roads free of sediment, including

the use of recirculating wheel washers and road cleaners; the use of sustainable drainage concepts to control the sediment

content of surface water drainage within and not contained within

No change.

Wylfa Power Station


Miti igat on 2008 Revised mitigation 2013 drainage systems;

prevent water from entering excavations by using cut off ditches; and

ensure that there is provision for dealing with silty water, this may include on site settlement lagoons or arrangements to take silt laden water off site.

Compliance with relevant EA Pollution Prevention Guidance, including that on the siting of chemical/fuel storage facilities, use of bunding, handling protocols and spill response plans (e.g. PPG2; PPG5; PPG6; PPG11 & PPG21).

Traffic and Transport No specific mitigation is proposed due to the existing standard of the A5025, the route benefiting from accident records at or below the national average and because the changes in traffic flows are low. However, a Travel Plan will be implemented which will assist in reducing the number of trips generated by the station. This plan will be discussed in advance with the relevant highway authority. Wheel washing of HGVs as necessary.

In addition to those listed opposite, the following mitigations have been identified. To reduce the traffic and transport impacts associated with the decommissioning of Wylfa, a Traffic Management Plan be prepared and agreed with the Highway Authority for the Care and Maintenance Preparations and Final Site Clearance phases. The traffic and HGV generations during the Care and Maintenance phase are relatively low and whilst Travel Plan measures, such as car sharing, will be encouraged, no specific measures are proposed for this phase. The Traffic Management Plan will set out measures to reduce the impact of HGV movements as set out in in the examples provided in Appendix 18.1 of the 2008 ES. To reduce the impact associated with staff (including contractors, Magnox staff, etc) travelling to and from the site the Traffic Management Plan will contain travel planning measures. Initially this will include measures to encourage staff to car share when travelling to and from the site and providing information on sustainable travel options before developing the measures further following feedback/surveys with staff when decommissioning commences. A monitoring regime will also be set out to determine the effect of the travel planning measures and monitor overall traffic generations during the decommissioning. This monitoring regime could include surveying staff


Mitigation 2008 Revised mitigation 2013 travelling to the site to find out how they travel and determine what measures may work to achieve modal shift, as well as the introduction of a permanent traffic counter at the site entrance which could monitor the traffic generations during the decommissioning. The Traffic Management Plan will also be updated if/when the works associated with decommissioning Wylfa coincide with significant neighbouring developments, such as the proposed new nuclear power station at Wylfa. It is considered that although cumulative traffic and transport impacts will be higher, there may be opportunities for significantly reducing the individual impact associated with the decommissioning of Wylfa through a combined Traffic Management Plan. Measures could include: co-ordinating HGV movements (so that if periods of intense HGV movements are expected for the proposed new nuclear power station at Wylfa then it may be possible to minimise HGV movements for the decommissioning and vice versa), potentially sharing facilities such as the Marine Offloading Facility (MOLF) which may be provided as part of the proposed new nuclear power station at Wylfa, and/or recycling material within the wider site (e.g. using surplus topsoil generated by the proposed new nuclear power station at Wylfa for in-filling on the decommissioned site). Travel planning opportunities for decommissioning staff travelling to site could also be increased by the presence of the proposed new nuclear power station at Wylfa. This could include having a greater chance of finding a partner to car share to work with and allowing decommissioning workers to also use the accommodation to be provided for the construction workers associated with the proposed new nuclear power station at Wylfa, thereby being able to car share/use shuttle bus services or other travel planning mitigation measures put forward as part of the proposed new nuclear power station at Wylfa.

wylfa nuclear power station - hse

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