wylfa nuclear power station

WYLFA NUCLEAR POWER STATION

NON‐TECHNICAL SUMMARY

OF THE ENVIRONMENTAL STATEMENT 2013 UPDATE

WYLFA NUCLEAR POWER STATION

NON-TECHNICAL SUMMARY

OF THE 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, Cemaes Bay, 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 of this document can be obtained from the following address: Document Centre, Magnox, Wylfa Power Station, Cemaes Bay, Isle of Anglesey, LL67 0DH. © Magnox Ltd 2013

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TABLE OF CONTENTS

1. INTRODUCTION: HOW AND WHY IS WYLFA APPLYING FOR CONSENT TO DECOMMISSION? 6

1.1. Background to the Application to Decommission Wylfa 6

1.2. Approach to Gaining Consent 7

1.3. Stakeholder Engagement 7

1.4. Method for the 2013 Update 8

2. THE WYLFA SITE 9 2.1. The Site Surroundings 10

3. THE DECOMMISSIONING PROJECT 11 3.1. How Will the Work be Managed? 12

3.2. Change in Decommissioning Strategy since 2008 14

4. WHAT DEVELOPMENT PROJECTS IN THE WYLFA AREA COULD AFFECT OUR PLANS? 14

4.1. Nuclear New-Build 14

4.2. Other Infrastructure projects in Anglesey 14

5. THE ROLE OF THE ENVIRONMENTAL MANAGEMENT PLAN (EMP) 15

6. THE ENVIRONMENTAL IMPACT ASSESSMENT 16

6.1. AIR QUALITY AND DUST 16

6.2. ARCHAEOLOGY AND CULTURAL HERITAGE 16

6.3. ECOLOGY 16

6.4. GEOLOGY, HYDROGEOLOGY AND SOILS 17

6.5. LANDSCAPE AND VISUAL 18

6.6. NOISE AND VIBRATION 18

6.7. SOCIO–ECONOMIC 19

6.8. SURFACE WATERS 20

6.9. TRAFFIC AND TRANSPORT 21

7. RESIDUAL IMPACTS 21

8. CONCLUSION OF THE 2013 UPDATE 22

1. INTRODUCTION: HOW AND WHY IS WYLFA APPLYING FOR CONSENT TO DECOMMISSION?

Wylfa Nuclear Power Station (hereafter Wylfa) will cease electricity generation and commence decommissioning in the next few years. In order to decommission, Wylfa must obtain consent from the Health and Safety Executive (HSE). The Office for Nuclear Regulation (ONR) is the agency of the HSE that deals with decommissioning consents, and both the HSE and ONR are referred to in this document. To obtain consent to decommission, Wylfa must prepare an Environmental Statement (ES), with a Non-Technical Summary (NTS) that explains the decommissioning projects, and states its environmental impacts and the steps Wylfa will take to mitigate or offset any of these impacts. It is important to note that Wylfa already has a decommissioning consent in place. However, as a result of the successful extension of the generating life of Wylfa, this consent will expire before decommissioning can commence and therefore a new consent is required. This NTS is based upon the findings of a Environmental Statement 2013 Update document, (referred to here as the ‘2013 Update’) which updates the previous ES that Wylfa submitted in support of its existing decommissioning consent. Figure NTS 1: 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 HSE with an Environmental Statement (referred to here as 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 works. 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.

Wylfa Power Station

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

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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 September 2014. Though work is on-going to extend this to December 2015 assuming the appropriate consents are received. 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

After consultation with the ONR, Magnox have decided to adopt the following approach to gaining a new consent:

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 (1) a 2013 Update Document and (2) a Non-Technical Summary (this document); and

Re-apply for consent, by submitting the 2013 Update Document 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 (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 is described in the 2013 Update Document.

1.3. Stakeholder Engagement

Stakeholder engagement is a key component in the process of gaining consent to decommission. It ensures transparency in the project and its impacts, and provides all stakeholders with 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 was an extensive and comprehensive engagement, the role and 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 group 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 NTS 1).

Photograph NTS1: Stakeholder poster at the Wylfa Information Centre

1.4. 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.


2. THE WYLFA SITE

Wylfa is located on the north coast of the Isle of Anglesey at Wylfa Head, Cemaes Bay (see Photograph NTS 2 below, and also in the 2008 ES, 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 hectares 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 centre, 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 the National Grid Company. They are located in close proximity to the outer security fence, but the substations are not part of the decommissioning project.

Photograph NTS2: View of Wylfa Nuclear Power Station and Surrounding Area


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2.1. 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 Part One, Section 4 of the 2008 ES and in the individual technical sections of Part Two. A summary of the area surrounding Wylfa is presented in Box NTS1 below. Box NTS1: 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 Bay 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 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 abstracted 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. 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. There are no major aquifers.

Nearest Settlements: Tregele 1km south-west.

Cemaes 2km south-east. Amlwch 9km east. Holyhead (nearest town with over 10,000 inhabitants) 27km south-west.

Designated Sites of Conservation 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.

Archaeology and Cultural Heritage 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 Register of Landscapes, Parks and Gardens of Special Historic Interest in Wales.

Historic Battlefields:

There are no registered historic battlefields within the study area.

3. THE DECOMMISSIONING PROJECT

The decommissioning project is described in Section 6 of the 2008 ES. This comprises three main 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 the Care & Maintenance Preparations phase. Following the Care and Maintenance 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 NTS 2 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 NTS 2: 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. The Reactor buildings will be clad and ‘safestored’ – which means that they will be prepared for the next stage of decommissioning. A radioactive waste storage facility will be built to house some waste. Some lower activity radioactive wastes will leave the site for disposal or recycling.

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. The radioactive waste store will be emptied and demolished during this period, as soon as practicable after a national waste repository is available. Photograph NTS3 shows an artist’s impression of Wylfa during this time.

Final Site Clearance is the last stage and is expected to take about 8 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.

Photograph NTS 3: An artist’s impression of the reactor building and radioactive waste storage building during Care and Maintenance


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3.1. How Will the Work be Managed?

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.

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 some radioactive wastes and for subsequent waste packaging operations, but these operations will take place within buildings only.

Numbers of Workers The current power station workforce currently comprises of 589 permanent staff and around 100 subcontractors1. Numbers of workers will fluctuate over the project but the maximum number of workers on site will be about 600 during Care and Maintenance Preparations, with no permanent presence expected 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 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 or so 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. There will be a need to remove the contents of the radioactive waste store, and demolish the building, but traffic movements associated with this are not considered significant (and will be well below current the levels of traffic generated by Wylfa). Again excluding routine deliveries of consumables, 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. 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

1 There has been a small reduction in staff numbers at Wylfa since the 2008 ES was published.


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was operational. However, there may be peaks resulting from certain activities. All discharges will be made in accordance with authorisations granted by the Environment Agency (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 NTS 3. 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 Environment Agency as required under the terms of the discharge authorisation.

Box NTS 3: 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 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 gaining appropriate approval.


3.2. 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 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 the 2013 Update document.

4. WHAT DEVELOPMENT PROJECTS IN THE WYLFA AREA COULD AFFECT OUR PLANS?

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. Since the 2008 ES was prepared, a number of significant infrastructure projects have been identified as being potentially located in Anglesey. By far the most significant proposal for the area around Wylfa is the proposed construction of a new nuclear power station.

4.1. Nuclear New-Build

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. 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.

4.2. 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).


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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 put Anglesey at the forefront of energy research and development, production and servicing, bringing with it potentially significant economic investment. 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 none of the major infrastructure projects are sufficiently mature for their impacts to be taken directly into account at this time. Marine Current Turbines proposals have been reviewed, and it has been concluded that there is no potential for any cumulative impacts, though this, and all other development-related impacts, will be kept under review.

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

As explained above, 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 Environmental Management Plan (EMP)2. The EMP describes the mitigation measures that Wylfa will use to prevent, reduce and where possible offset any significant adverse effects on the environment caused by decommissioning Wylfa.

The EMP is re-issued annually and submitted to the HSE / ONR and the EMP is also available to stakeholders and the public, and at other Magnox sites the ONR has audited performance against the EMP3. The EMP will also be used to record any changes that we need to make to our mitigation proposals (as agreed with the ONR and other regulators) during the course of the

2 Wylfa Site Environmental Management Plan Issue 3 June 2012 3 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


decommissioning project, including any required to offset any cumulative impacts caused by the proposed new nuclear power station at Wylfa. The EMP also reports on the effectiveness of the mitigations we have employed.

6. THE ENVIRONMENTAL IMPACT ASSESSMENT

The Environmental Impact Assessment (EIA) process identifies the potentially significant environmental effects associated with a project, e.g. decommissioning, and allows them to be taken into account in the decision making process. The topic areas that were considered in the assessment are considered individually below.

6.1. 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.

The approach and mitigation measures identified in the 2008 ES are considered to remain valid. Following consultation with Isle of Anglesey County Council’s Environmental Health Officer, more prescriptive measures for monitoring Air Quality and Dust have been identified.

6.2. 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.

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.

6.3. 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;


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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.

Since the 2008 ES was prepared, it has been confirmed that a pair of choughs, a specially protected bird species that is listed on Schedule 1 of the Wildlife and Countryside Act 1981, have nested at Wylfa.

The impacts outlined within the 2008 ES are considered to remain valid, but 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 will 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 decommissioning works that could affect choughs. 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 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. 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 the Countryside Council for Wales (which will become Natural Resources Wales in April 2013) prior to the commencement of decommissioning works

6.4. 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 infill material;

Inadvertent effects on groundwater flow and quality due to infilling 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).

It is predicted that potential adverse impacts will arise during the Care & 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.

6.5. 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.

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 Countryside Council for Wales and Isle of Anglesey County Council.

6.6. 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 Heavy Goods Vehicles (HGVs)). The traffic data used in the assessment took into account predictions of future changes in background traffic.


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As agreed with Isle of Anglesey County Council, 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’ (under the Control of Pollution Act 1974) which will be made directly with Isle of Anglesey County Council. The Section 61 agreement is a formal agreement between the Wylfa and the Isle of Anglesey County Council where noise levels, hours of work and any mitigation are agreed upon.

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 will provide for a more robust assessment of the noise impacts and the identification of more specific mitigation measures to reduce noise impacts. It will ensure that the most appropriate mitigation is implemented for the proposed works to be carried out. The mitigation will need to be specific and demonstrate to Isle of Anglesey County Council 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.

6.7. 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.

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;

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 (including the owners of the proposed new nuclear power station at Wylfa) would be pursued where socio-economic gains could be secured.

6.8. 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.

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


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6.9. TRAFFIC AND TRANSPORT

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

7. 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 consents 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 European State.

8. CONCLUSION OF THE 2013 UPDATE

This 2013 Update 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.

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 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 Cemaes Bay 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 Ltd 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 Bay 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/

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