topical research meeting physics. innovation. nuclear · 2019. 9. 1. · p1. coastal erosion of a...

1–2 November 2017Manchester Victoria & Albert Hotel,

Manchester, UK

http://pin2017.iopconfs.org/

Topical Research Meeting

Physics. Innovation. Nuclear

Programme and Abstract Book

Contents

Organising committee 2

Sponsors 2

Sponsor adverts 3

Programme 5

Poster programme 7

Invited talks 8

Posters 16

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Organising committee

• Ben Chapman, Sellafield Ltd • Doug Cragg, Sellafield Ltd • Thomas Dowd, Sellafield Ltd. • Adam Dugdale, Sellafield Ltd • Dale McQueen, Sellafield Ltd • Rebecca Sparkes, Sellafield Ltd

Sponsors

Partner organisations

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http://www.ntec.ac.uk/https://www.gov.uk/government/organisations/sellafield-ltdhttp://www.nuclearinst.com/Events-Calendarhttp://www.niauk.org/

1–2 November 2017Manchester Marriott Victoria & Albert Hotel,

Manchester, UK

ProgrammeWednesday 1 November

09:00 Arrivalandcoffee(Foyer)

09:45 WelcomefromProfessorSarahThompson,UniversityofYork,UK(JLBSuite)

10:00 Keynote: Technical challenges for Sellafield NeilSmart,SellafieldLtd,UK

10:40 Radiological characterisation and assay in support of Magnox Reactor decommissioning ChrisGoddardandBillWestall,MagnoxLtd,UK

11:20 Existing fleet life extension PaulStyman,NationalNuclearLaboratory(NNL),UK

12:00 Lunchandposterpresentations(Foyer)

13:00–15:00 Disposal of Radioactive Waste and Innovations in Waste Management The NDA’s strategic approach to integrated waste managementJamesMcKinney,NDA,UK Management of innovation in radioactive waste managementPaulSkelton,RadioactiveWasteManagement,UK Decommissioning and innovation in waste management at SellafieldEdMatthews,SellafieldLtd Waste vitrification – developing thermal treatment routes for UK wastesRussellHand,UniversityofSheffield,UK

15:00 Coffeebreak(Foyer)

15:30 Mapping radiation with a mobile gamma imaging instrument NeilOwen,Createc,UK

16:00 Panel session 1 HowcantheUKnuclearindustrycapitaliseonitsnuclearlegacy?

HowcanphysicssupporttheUK’sambition?

16:45 Closeofdayone

18:30 ConferencedinneratMuseumofScienceandIndustry



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Manchester, UK



Thursday 2 November

09:00 Keynote: Challenges and opportunities – the UK civil nuclear R&D landscape PaulNevitt,NIRO,UK(JLBSuite)

09:40–10:30 SMR technologies and developments in UK UK SMR development programme – a national endeavour SimondeHaas,Rolls-Royce,UK SMRs – rest of the world (RoW) perspectivesJohnLillington,Wood,UK Q&A

10:30 Coffeebreak(Foyer)

11:00 IAEA activities in the area of nuclear power reactor fuel engineering MikhailVeshchunov,InternationalAtomicEnergyAgency(IAEA),Austria

11:30 The UK nuclear R&D programme on digital reactor design BenLindley,Wood,UK

12:00 Lunchandposterpresentations(Foyer)

13:15 Diversity – the key to innovation? DawnWatson,SellafieldsLtd,UK

13:45 Initiatives to support knowledge and skills development in the nuclear industry JonBillowes,UniversityofManchester,UK

14:30 Industry strategy and nuclear sector deal ChrisSavage,NuclearIndustryAssociation,UK

15:15 Panel session 2 WhatdoesthefutureholdfortheUKnuclearindustry?

Isthenuclearindustryreadyforthe21stCentury?

HowcanphysicssupporttheUK’sambition?

15:45 Posterpresentationaward

16:15 Closeofevent

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Manchester, UK

PosterprogrammeP1. Coastal erosion of a low level waste disposal site SamStead,LLWRepositoryLtd,UK

P2. The power partitioning method for generating AGR graphite dosimetry data JamesWatson,AmecFosterWheeler,UK

P3. Innovation throughout the lifecycle for nuclear power plant operations DarylLandeg,ANRC/UniversityofStrathclyde,UK

P4. Development and computational modelling of a plastic scintillator system to characterise the temporal properties and magnitudes of pulsed radiation sources AdamWoodward,AWE,UK

P5. Characterization of the crystalline structure of neutron-irradiated graphite MarzoqaAlnairi,TheUniversityofLeeds,UK

P6. Semi-autonomous robotic mapping systems for nuclear decommissioning and maintenance AndySmith,DaltonCumbrianFacility,UniversityofManchester,UK

P7. Radiation detectors for high temperature environments using single crystal diamond DavidSmith,BrunelUniversityLondon,UK

P8. Graphite post irradiation evaluation & new techniques research HenryPreston,NNL,UK

P9. Mapping of pH, temperature and turbidity in legacy waste storage ponds JessicaHyde,UniversityofManchester,UK

P10. Accelerated radiation damage of nuclear materials AndySmith,DaltonCumbrianFacility,Universityof

Manchester,UK

P11. UK nuclear data network PaulDavies,UniversityofManchester,UK

P12. Strain Localisation in proton irradiated Zircaloy-4 measured using digital image correlation RhysThomas,UniversityofManchester,UK

P13. Multiple cascade radiation damage simulations of pyrochloresIvanScivetti,DaresburyLaboratory,ScienceandTechnologyFacilitiesCouncil,UK

P14. Characterisation of redundant multi-element bottles using the multi-element bottle residual activity measurement method AntoniaCallaghan,SellafeldLtd,UK

P15. Neutron-gamma imaging with compton camera and coded aperture HajirAlHamrashdi,LancasterUniversity,UK



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Keynote: Technical challenges for Sellafield

N Smart

Sellafield Ltd, UK

Sellafield Ltd faces a unique challenge in it evolution from a facility dominated by reprocessing activities to one in which the major activities will be waste management and decommissioning of legacy facilities on the site. This transformation will be both cultural and technical. In turn, the transformation yields the opportunity for innovation in both technology and the approaches taken to problem solving. It will look to utilise technological solutions that are fit for purpose but, where appropriate, deploy tools that are first of a kind in the decommissioning environment.

Radiological characterisation and assay in support of magnox reactor decommissioning

C C Goddard and W A Westall

Magnox Limited, UK

At the end of generation, power reactors will be decommissioned. Whether decommissioning is prompt or deferred, knowledge of the radioactive inventory of plant and structures is needed to develop and underpin the decommissioning strategy. As decommissioning progresses the level of detail required for the radioactive inventory increases as more specific and detailed questions need answering. Failure to adequately characterise will result in increased costs and project overruns due to missing optimal solutions, over pessimistic assumptions, unforeseen problems and regulatory issues.

Radiological characterisation for decommissioning of Magnox power stations in the UK has been in progress for over a quarter of a century. Firstly measurements and calculations were carried out to develop a strategy. These have been followed by measurements to determine radioactive inventories of waste streams and packages, to allow decontamination of structures and most recently for partial delicensing of sites.

Some examples of the work carried out for the Magnox stations will be given:

• neutron activation calculations to estimate the radioactive inventory within a bioshield and some validation measurements

• measurements on various items of plant such as the gas circuits and pond water clean-up plant where the radioactivity is due to contamination

• measurements to determine the level of contamination of structures such as the cooling ponds.

Some wastes are not accessible until retrieval so that assay is required during processing. The assay of waste measures only a small subset of radionuclides that are practically detectable. These issues present some difficult challenges, particularly how waste can be packaged to meet the many limits with a high degree of confidence. The history of the site and generation of the wastes needs to be taken into account when developing the algorithms used to derive a radioactive inventory from the assay measurements and also to understand the uncertainties associated with the radioactive inventory. The waste package type also influences the information that needs to be obtained from the assay with some types far more demanding than others.

The solutions found to overcome these challenges for the Berkeley Active Waste Vaults will be discussed.

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The NDA's strategic approach to integrated waste management

J McKinney

NDA, UK

The NDA is now moving towards a single radioactive waste strategy for its estate that will need to demonstrate how it will support all relevant policies in the UK. Our radioactive waste strategy will evolve to place greater emphasis on the nature of the wastes (radiological, chemical and physical properties) rather than classification (e.g. ILW and LLW). As a first step, the NDA is highlighting a lifecycle approach to waste strategy that involves the following key steps: planning and preparation, treatment and packaging, storage and disposal. Developing a single radioactive waste management framework for all of our sites will provide greater clarity of our strategic needs, promote cross-category opportunities and support a risk-based approach to waste management.

Management of innovation in radioactive waste management

P Skelton

Radioactive Waste Management Limited, UK

It is only a recent as the late 1980’s that the strategy of the UK nuclear industry has been to condition intermediate level wastes at the time of arising, prior to that the industry approach was primarily to place unconditioned wastes into interim storage facilities many of which are now the focus of some of the most significant decommissioning challenges faced by the UK civil nuclear sector. Since the adoption of this approach the UK civil industry has tended towards the use of the ”trusted” technologies, primarily the OPC based grout systems which were developed and adopted as the standard at the time.

As the focus of the industry moves beyond the completion of the reprocessing missions and into the waste retrieval and treatment, reactor decommissioning and broadfront decommissioning phases, the range of wastes which will arise across the estate will become more diverse and raise new challenges to these established approaches for waste treatment.

Against this change in the challenge that the industry faces it is important to ensure that the organisations involved at all stages of the waste management lifecycle have an active role in the adoption of innovative techniques which can ensure that the waste can be managed safely, packaged to enable safe waste disposal and demonstrate value for money to the tax payer. The adoption of innovation in the area of waste management has not always been an easy or predictable journey, particularly where the adoption of innovative approaches could pose a risk to successful project delivery, hence the preference to stick with the tried and trusted approaches. This presentation considers the issues of adoption of innovation while highlighting the approaches that waste management organisations are taking to improve our appetite for innovation.

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Decommissioning and innovation in waste management at Sellafield

E Matthews

Sellafield Ltd, UK

Introduction

Sellafield is the home of the World’s first full scale Nuclear Power station at Calder Hall, opened by the Queen in 1956, the UK nuclear industry is well over 60 years old, and has developed a mature and capable decommissioning industry.

The technical challenges faced at UK decommissioning sites such as Sellafield, Magnox and Dounreay, have many similarities to those at Fukushima Dai-ichi; The UK has built an unrivalled knowledge of retrieving and correctly disposing of highly radioactive, sometimes unknown wastes, which has a direct application to the situation at Fukushima Dai-ichi.

The challenges in the UK are met by many different companies working together with Nuclear Decommissioning Authority to ensure that decommissioning is completed in the most efficient manner. This collaborative approach to decommissioning has brought many significant benefits.

Decommissioning at Sellafield

Sellafield has many large and varied decommissioning challenges. The most well-known are the four legacy ponds and silos. The earliest, the Pile Fuel Storage Pond, began construction in the 1940’s and last material was placed into the Magnox Swarf Storage Silo in 2000. All four are part of a £400M per year programme stretching until 2040’s.

Fit for purpose approaches combined with a clear risk framework enable effective decision making to secure best value for this significant expenditure. Some of the decommissioning requires new facilities but wherever possible existing facilities are re-engineered and staff are re-skilled.

Innovation in Waste Management

Innovation in waste management is focused on improving the approach to decommissioning through waste management. This has been used in the approaches to waste retrievals; the storage of the retrieved material and re-engineering facilities to receive material significantly sooner than the original plan, reducing the timescales and costs for decommissioning.

Next Steps

The life time plan for Sellafield [1][2] is currently due to be completed in 2120. As decommissioning methods are identified, tested, developed and deployed the detail of the future plans can be refined and enhanced.

Throughout all of this, our focus is threefold, safe and secure management of the site, delivering progress and demonstrating value for money.

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[1] Sellafield Performance Plan http://www.sellafieldsites.com/wp-content/uploads/2015/03/Performance-Plan_single.pdf

[2] Sellafield Corporate Strategy http://www.sellafieldsites.com/wp-content/uploads/2017/04/FINAL-PDF-Corporate-Strategy.pdf

Waste vitrification - developing thermal treatment routes for UK wastes

R Hand

University of Sheffield, UK

In this presentation I will review the application of thermal treatment routes for the treatment of intermediate level wastes in the UK, including an examination of the major benefits such as the production of stable wasteforms with significant volume reduction, as well as some of the challenges posed by the use of thermal processes. The primary focus will be on waste vitrification although the production of glass ceramic materials will also be considered. Specific examples of wasteform development undertaken by the ISL at the University of Sheffield will be used to demonstrate that suitable glass or glass ceramic compositions can be developed for a wide variety of wastes, including sludges and ion exchange resins.

Mapping radiation with a mobile gamma imaging instrument

N Owen

Createc, UK

In decommissioning, radiation monitoring and remediation it is often necessary to map and quantify radioactive contamination in areas quickly and efficiently with minimal human exposure.

Our solution is a simple and intuitive handheld instrument that can be deployed by non-experts. The user initiates a survey by pressing a single button and walking around the area. The instrument displays the video from the camera mounted on the front of the instrument with a realtime overlay showing the source location of any detected gamma radiation. The user then builds up the gamma image by manually sweeping the sensor over the area of interest.

It’s possible to cover wide areas rapidly at a low resolution by stepping back from them and fill in detailed areas more rapidly by stepping closer. The system provides the user with a visual indication of which parts of the image have adequate exposure so they can keep sweeping the system over the survey area until the desired resolution is reached.

The system is based on two existing technology platforms, developed by Createc: the N-Visage 3D radiation mapping engine and Createc’s real-time Laser Rangefinder (LiDAR) positioning system, used on RISER, our Unmanned Aerial Vehicle (UAV). For the Handheld N-Visage we developed a simplified version of the 3D mapping engine that is capable of fusing the radiation data and 3D data together in real-time.

The picture shown is a panoramic 2D Radiation Gamma Image obtained using the N-Visage system at Fukushima, Japan.

The instrument’s camera pose is calculated by the LiDAR positioning system and this information can be used to render the 3D activity model as it would be seen from the current camera view. This image is then displayed as a transparent overlay on the real-time video image. This means that as the user moves the sensors, both the video image and the rendered gamma image align perfectly – in effect, this is an augmented reality display of the contamination source.

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http://www.sellafieldsites.com/wp-content/uploads/2015/03/Performance-Plan_single.pdfhttp://www.sellafieldsites.com/wp-content/uploads/2015/03/Performance-Plan_single.pdfhttp://www.sellafieldsites.com/wp-content/uploads/2017/04/FINAL-PDF-Corporate-Strategy.pdfhttp://www.sellafieldsites.com/wp-content/uploads/2017/04/FINAL-PDF-Corporate-Strategy.pdf

Challenges and opportunities – the UK civil nuclear R&D landscape

P Nevitt

Nuclear Innovation and Research Office (NIRO), UK

Focusing on the work of the Nuclear Innovation and Research Advisory Board (NIRAB) and the Nuclear Innovation and Research Office (NIRO), this presentation will explore some of the challenges and opportunities for civil nuclear innovation and research. How does nuclear fit within the future UK energy landscape?

NIRAB was established in January 2014 as a temporary advisory board for a period of up to three years. It was charged with advising Ministers on the publicly funded civil nuclear research necessary to underpin policies (particularly industrial and energy policies). NIRAB was supported by NIRO which provided a secretariat function.

NIRAB research programme recommendations were focussed on closing gaps in the current nuclear Research and Development (R&D) landscape; in particular those gaps associated with new reactor systems which, in the absence of action, would prevent the UK realising the economic and industrial potential in low carbon nuclear energy. This presentation will discuss in more detail the recommendations of NIRAB and how these contributed to the development of the Department for Business, Energy and Industrial Strategy (BEIS) Nuclear Innovation Programme.

NIRAB and NIRO, on behalf of Government, updated the civil nuclear R&D landscape survey in 2016 which provides a quantitative assessment of the evolution of the research landscape since data was last published in 2013. The output of the 2013 review was used to provide the baseline from which the future aspirations for the UK’s R&D capability were drawn. The results of the latest landscape survey will be presented and discussed, illustrating the evolution of the nuclear research and innovation landscape in the UK.

Finally, Government recently announced that they wish to reconvene NIRAB and extend the remit of NIRO. This presentation will conclude by looking at the scope of work ahead for NIRAB and NIRO in providing advice to Government on the challenges and opportunities for nuclear innovation and research.

UK SMR development programme – a national endeavour

S de Haas

Rolls-Royce, UK

The talk will provide a summary of the Rolls-Royce UK SMR ‘National Endeavour’ programme. It will cover why the UK needs an SMR programme, present a brief overview of the Rolls-Royce programme and concept design, then show some examples of where physics is driving innovation to help us build a power station that can generate electricity at the lowest possible price.

SMRs – Rest of the World (RoW) perspectives

J Lillington

Wood, UK

This presentation will provide an overview of national and international programmes supporting Small Modular Reactor (SMR) development. It will briefly describe UK Government strategy for SMR and some of various initiatives that culminated in the UK SMR competition. It will describe the main features of SMRs (in comparison with ‘large reactors’), focusing on the enhanced performance and safety features, also mentioning briefly other issues (e.g. economic issues). SMR designs in common with other later generation

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reactor designs put greater emphasis on inherent safety. The presentation will show examples of some of the designs that are at advanced Technology Readiness levels (TRLs).

IAEA activities in the area of nuclear power reactor fuel engineering

M Veshchunov

International Atomic Energy Agency (IAEA), Austria

The main IAEA program implementation tools in the area of fuel engineering are Coordinated Research Projects (CRP), Technical Meetings (TM), Expert Reviews, and NEA-IAEA International Fuel Performance Experiments (IFPE) Database. This report provides information about organization and implementation practices of these activities, and summarizes their major outputs including ongoing CRPs and TMs in the area of Fuel Engineering.

The UK nuclear R&D programme on digital reactor design

B Lindley

Wood, UK

An Integrated Nuclear Digital Environment is being developed to address a growing need for integrating multiphysics modelling and work towards the creation of a digital twin for a nuclear reactor.

Diversity - the key to innovation?

D Watson

Sellafield Ltd, UK

Diversity is currently a hot topic, which is discussed and highlighted now in many areas of society and business. Moving on from just equality, the careful consideration of diversity within teams is cited to assist with innovation. In fact recent research has provided additional evidence that having a diverse management team is a valuable asset when it comes to innovation [Ref 1]. This talk will describe the links found between diversity and innovative thought and also touch on some of the research done recently in this area. It will also aim to describe how we can all become more aware of how we may be unconsciously stifling diversity and how we can think differently to address the issue.

[1] The Mix that Matters: Innovation through Diversity, April 2017, BCG

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Initiatives to support knowledge and skills development in the nuclear industry

J Billowes

University of Manchester, UK

The Squires Report for HSE NII in 2002 revealed the dire state of nuclear education in the UK. Nuclear Engineering had disappeared as an undergraduate subject, academics and facilities were ageing, and only two institutions offered a postgraduate qualification relevant to nuclear engineering. This “wake-up” call galvanised universities, research councils and eventually Government into action.

The Nuclear Technology Education Consortium (NTEC), established in 2005, brought together nine UK universities which still had pockets of nuclear expertise plus the Nuclear Department of the Defence Academy to provide a Master’s level programme in nuclear science and technology. Initially funded by the Engineering and Physics Sciences Research Council (EPSRC), the innovative delivery of the programme in one-week modular courses is unique for a nuclear Master’s programme in the UK and was developed after consultation with industry to allow the attendance, on a part-time basis, of the currently-employed workforce. With over 200 students having also studied on the programme on a full-time basis, with 80% either entering the nuclear industry directly, or embarking on further nuclear education programmes, NTEC is also contributing to the expansion of the nuclear workforce as well as its enhancement.

The following year EPSRC funded the UK’s first Nuclear Engineering Doctorate (EngD) Centre, led by the University of Manchester in partnership with Imperial College, London and supported by four other universities. Its programme combined the academic strengths of a conventional PhD with the practical benefits of linking the research to the specific needs of a collaborating company. One of the key features of the EngD therefore is that the research project is sponsored by and undertaken within an industrial organisation as opposed to within a university.

Other Centres for Doctoral Training (CDTs) have been established in the nuclear area, with EPSRC and industry funding, which focus on the more conventional university-based PhD with the aim to develop the future subject experts and leaders of the nuclear industry. Currently these CDTs are Next Generation Nuclear led by Manchester in partnership with four other universities, and the ICO Centre for Nuclear Energy involving Imperial, Cambridge and Open University.

In 2015 the Government launched the nuclear scientist and nuclear engineer Degree Apprenticeship scheme which will allow students with a good A level background to join a company as an apprentice and gain a full bachelor’s or master’s degree from a university while earning a wage and getting real on-the-job experience in their chosen profession. The current status of this initiative will be reviewed.

Industry strategy and a nuclear sector deal

C Savage

Nuclear Industry Association, UK

The UK’s civil nuclear sector is amongst the most advanced in the world, with capability through the entire life of nuclear generation, from design and fuel manufacture, through generation, operation, new build, research and decommissioning, as well as providing tens of thousands of highly skilled, high technology jobs.

The existing fleet of nuclear power stations provides more than 20% of the UK’s electricity supply, and its low carbon, reliable baseload characteristics complement a changing energy system with a greater penetration of intermittent and variable renewable sources of generation.

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The government’s industrial strategy provides an opportunity to secure and grow the industry’s contribution for the decades ahead, and the industry has been identified as one of five sectors to bring forward early sector deals. The potential is not only the next generation of nuclear power, to replace the UK’s current ageing infrastructure, but also the development of new technology and fostering innovation that will impact power generation decades into the future.

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Posters

P1. Coastal erosion of a low level waste disposal site

S Stead and A Huntington

LLW Repository Ltd, UK

The Low Level Waste Repository (LLWR) is the UK’s primary facility for the disposal of low level radioactive waste. LLWR are required by our permit to submit and maintain an Environmental Safety Case (ESC) that demonstrates the safety of disposals now and in the future. The most recent ESC was submitted in 2011 (the 2011 ESC)[1] and LLW Repository Ltd is currently undertaking a programme of work leading to the production of an updated ESC in 2021[2].

At its closest point, LLWR is approximately 500 metres from the coast. Historical evidence indicates that the coast has receded, and it has long been understood that coastal erosion may impact the site in the future. The aim of this contribution is to summarise our past and future work on forecasting and assessing the impacts of coastal erosion at the LLWR site.

P2. The power partitioning method for generating AGR graphite dosimetry data

D Allen, J Watson, D Thornton and J Hagues

Amec Foster Wheeler, UK

The safety cases for continued operation of the Advanced Gas-Cooled Reactors (AGR) require a robust understanding of the structural integrity of their constituent graphite bricks. Both neutron damage and graphite weight loss have significant and detrimental effects upon the key material properties upon which structural integrity assessments are based. Weight loss occurs via radiolytic oxidation which is initiated by both neutron and 𝛾-ray dose (collectively known as nuclear heating). Nuclear heating includes contributions from fast neutrons, 𝛾 -rays from the fuel, and secondary 𝛾 -rays generated from neutron interactions.

Material property “trend curves” are largely tuned to data derived from measurements using samples trepanned from fuel channels. Therefore an accurate knowledge of the dosimetry history of these samples (damage and nuclear heating) is important, as well as the ability to make forward predictions for any brick within the core. It is therefore necessary to calculate both of these dosimetry quantities with a high degree of spatial accuracy, taking into account the time-varying nature of local fuel channel powers as well and the way in which weight loss itself affects the dosimetry data.

The Monte Carlo method is the most accurate available for the calculation of radiation dosimetry data. The ANSWERS code MCBEND is the code of choice for this task, having a well-established pedigree and being supported by a range of suitable validation evidence. However, it is impractical to undertake full scale Monte Carlo calculations for a whole reactor core and to represent every required period of time and graphite weight loss (which will also vary in time and space). An alternative approach has been developed by Amec Foster Wheeler which exploits the high accuracy afforded by the Monte Carlo method, but is also flexible and practical enough to provide 3D dosimetry data for any graphite brick within the active core, at any point in time and at any required graphite weight loss.

The “Power Partitioning” method uses MCBEND-generated dosimetry “Contribution Matrices”, coupled with PANTHER “core follow” fuel power data, to calculate dosimetry data anywhere within selected fuel channels or interstitial bricks.

The dosimetry data at any location within a chosen subject brick (the central one in this diagram) is calculated as the power-weighted sum of the contributions from all the neighbouring fuel channels ( ),

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plus that from the subject channel itself. There is also a small contribution from remote channels beyond the immediate neighbours ( ). Not all contributions shown in this figure.

Where a vacant channel exists its power weighting is zero and a correction is made to account for the additional contribution from remote channels behind it.

The effect of graphite weight loss is accounted for by interpolation between dosimetry datasets generated at different graphite densities. The method also accounts for subject bricks which have atypical weight loss (different from its neighbours). Using this method it is possible to generate dosimetry data for any brick within the active cores of the AGRs.

The poster will present details of the modelling and methods used, including details of the corrections made for vacancies, remote channel contributions and axial details (fuel end dose depressions, grids & braces etc.).

MCBEND model of AGR moderator bricks and fuel channels, showing which channels contribute to graphite dose in a subject brick

P3. Innovation throughout the lifecycle for nuclear power plant operations

D Landeg

ANRC / University of Strathclyde, UK

Strathclyde University has a long track-record of working collaboratively with industry, public sector and academic partners to deliver industry-focused, sustainable centres which leverage private and public research funding to deliver tangible benefits to the economy.

This talk will describe the focus and vision for the Advanced Nuclear Research Centre [1] at the University of Strathclyde which was created in 2015 in collaboration with founding members Babcock International, Bruce Power, EDF Energy and Kinetrics. The centre connects academic research in diverse fields to industrial partner’s priorities to accelerate innovation across the lifecycle. Three current research themes will be briefly outlined.

1) Advanced sensors and data analytics 2) Waste management innovation

Subject Brick

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3) Applications for laser particle accelerators [1] https://www.strath.ac.uk/research/advancednuclearresearchcentre/

P4. Development and computational modelling of a plastic scintillator system to characterise the temporal properties and magnitudes of pulsed radiation sources

A Woodward

AWE, UK

A detector system has been developed for use in characterising pulsed radiation sources. Experimental trials have been undertaken to provide benchmark data for Geant4 modelling, which in turn is used to optimise the final detector design. Ensuring optimal light output whilst maintaining integrity of the pulse shape from the detector system is of critical importance. Geant4 modelling work has been undertaken to determine the ideal detector geometry and photomultiplier location to provide a large value of light output, without significantly compromising temporal resolution. The latest results of the modelling study will be discussed, along with an overview of experimental benchmark data obtained from steady state and pulsed sources which has been used to validate the models.

P5. Characterization of the crystalline structure of neutron-irradiated graphite

M Alnairi1, B Mironov1, W Windes2,3, A J Scott1, A V K Westwood1 and R M D Brydson1 1The University of Leeds, UK, 2Idaho National Laboratory, Idaho Falls, 3Center for Advanced Energy Studies, Idaho Falls

In this work, microstructural parameters, such as lattice dimension and the disorder within the lattice of four different neutron-irradiated graphite grades have been investigated using X-ray diffraction (XRD) and Raman spectroscopy techniques, which produced consistent results (see Figs 1a, b). The graphite samples (Generation-IV candidates) were irradiated at the Advanced Test Reactor at the Idaho National Laboratory (grades PCEA and PCIB both based on petroleum coke) and subjected to neutron irradiation doses ranging from 1.5 - 6.8 dpa with the irradiation temperature varied between 350°C - 670°C. Compared to virgin specimens of the same grade, XRD diffractograms of the two tested graphites illustrated that crystallite size decreased by roughly 40% (for both La and Lc) for low dose, low temperature samples, while for high dose, high temperature samples it reduced by roughly 50% (for both La and Lc) [1]. As correlating evidence, quantitative analysis of the G peak obtained from Raman spectra provided evidence for the fragmentation of crystallites following the same changes in irradiation conditions [1].

Figure 1: Schematic diagram showing (a) the measured XRD patterns of virgin and irradiated PCIB and PCEA graphites, (b) Raman spectra in 1000-3000 cm-1 wavenumber range of raw of the aforementioned nuclear

graphite grades (virgin and irradiated).

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https://www.strath.ac.uk/research/advancednuclearresearchcentre/

[1] Freeman, H.M., Mironov, B.E., Windes, W., Alnairi, M.M., Scott, A.J., Westwood, A.V.K. and Brydson, R.M.D., 2017. Micro to nanostructural observations in neutron irradiated nuclear graphites PCEA and PCIB. Journal of Nuclear Materials, 491, pp.221-231.

[2] This work was financially supported by the Umm AL-QURA University Al-Laith branch, Saudi Arabia. [3] Irradiated samples were provided by the Idaho National Nuclear Laboratory, US.

P6. Semi-autonomous robotic mapping systems for nuclear decommissioning and maintenance

A Griffiths, H Martin, J Jones, A Smith, X Poteau, S Watson and B Lennox

Dalton Cumbrian Facility/University of Manchester, UK

The University of Manchester Robotics (UoM Robotics) group is currently designing two robotic platforms at the Dalton Cumbrian Facility, located near the Sellafield site. These platforms are as follows: The CARMA system is a robotic system which has been designed as a tool for the fields of inspection and long-term monitoring of active facilities. CARMA uses current state-of-theart autonomous platform with a 2D LIDAR, integrated with nuclear industry standard radiometric sensors. This combination allows for real-time 2D radiation mapping of a known or unknown environment. The CARMA platform is currently under development and scheduled for active demonstrations on the Sellafield site. The Miniature Robot for Restricted Access eXploration (MIRRAX) is a reconfigurable mobile robotic platform which utilises omnidirectional wheels for exploration purposes within a restricted hazardous environments. The robot is specifically designed for accessing through existing master-slave manipulator ports into hot cells which are limited to 150mm, whilst carrying a payload of twin LIDARs for 3-dimensional mapping.

P7. Radiation detectors for high temperature environments using single crystal diamond

G Fern, P Hobson, A Metcalfe and D Smith

Brunel University London, UK

A number of harsh industrial environments require radiation detectors which can operate at temperatures in excess of 200 °C and may, in addition, require significant tolerance of the sensor to ionising radiation. Two application areas of current importance are the monitoring of radiation near high-pressure steam pipes in nuclear reactors used for electricity generation, and deep-level oil and gas exploration. With its wide band-gap of 5.5 eV and proven resistance to high levels of ionising radiation, single crystal CVD diamond is becoming well known as a radiation detector at normal ambient temperatures. We have been studying the performance of such sensors at elevated temperatures up to 250 °C as part of an EPSRC funded collaboration with Micron Semiconductor Ltd (UK) via a linked TSB project [1]. We have investigated leakage current, noise and the spectroscopic resolution for alpha particles in the few MeV energy range as a function of temperature and compared our results with Monte Carlo simulations using both FLUKA and MCNP6 codes [2]. Figure 1 shows simulated and experimentally recorded energy spectra from one of the commercially available 2×2×0.5 mm3 diamonds used in our detector design when exposed to a triple-alpha source ( 241Am, 244Cm, 239Pu) inside a vacuum chamber at < 10-5 mbar. Figure 2 shows data collected from one of our sensors operating at -300 V bias across a temperature range of 50 °C to 250 °C. We have conducted testing of four nominally identical sensors and have demonstrated charge collection efficiency ~ 99% and alpha peak energy resolution better than 1% up to a temperature of 200 °C. These initial results are very promising and show the potential of these sensors for use in harsh environments.

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P8. Graphite post irradiation evaluation & new techniques research

H Preston and N Tzelepi

NNL, UK

NNL is the sole provider for graphite Post Irradiation Evaluation (PIE), thanks to its facilities at Sellafield, and has had a history in this area for the past 40+ years. Graphite PIE is important for maintaining the safe operation of the UK’s Advanced Gas Reactor (AGR) fleet. PIE provides a greater understanding of graphite’s material properties and its behaviour under irradiation.

The graphite core of an AGR undergoes irradiation by fast neutrons, causing carbon atoms to be displaced within the lattice. This affects the strength, stiffness and thermal properties and causes the graphite either to shrink or to expand, depending upon the irradiation conditions. Graphite also oxidises in the carbon dioxide environment of AGRs, which affects its strength and stiffness.

To measure these affects, graphite samples are trepanned from the AGRs and sent to NNL Windscale for a variety of PIE techniques. The results of this help characterise the material properties of the graphite samples and provide a safety case.

There is still much to be understood about Graphite despite its use in AGRs, as a moderator, for the past 60 years. Therefore it is important, going forward, to continue research and to build on the current knowledge. The knowledge gained through PIE measurements and analysis will be used In the future to find solutions for graphite waste and generation IV reactor designs.

P9. Mapping of pH, temperature and turbidity in legacy waste storage ponds

J Hyde


Legacy ponds at Sellafield were used to prepare fuel for reprocessing and to store resulting waste. Radioactive materials have accumulated in the ponds, remaining there since routine operations were stopped. Deterioration and lack of clean out at the end of operations causes problems with decommissioning.

In the legacy fuel storage ponds containing magnox fuel pins, a caustic purge reduces corrosion of the pins by maintaining a constant pH and diluting any activity build up. During clean up, discharge from the ponds is transferred to settling tanks to reduce suspended solids before sending to downstream effluent treatment plants. In addition, sludge retrieval operations increase the burden on the pond purge operations which require good pond visibility.

NNL and sellafield need to track data relating to pH, turbidity and temperature to create models to understand purge and settling operations. So far probes have been deployed but not in sufficient numbers to provide the data needed for modellers. This project plans to make a 2D net of POF multisensory fibres which can be sensitised to pH, temperature and turbidity to monitor the settling characteristics and plume purge into the tank. While the fibres can be sensitised to measure to monitor activity the project will initially focus on non-active measurements with activity measurements added later.

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P10. Accelerated radiation damage of nuclear materials

A Smith, N Mason, S Shubeita and P W Wady

Dalton Cumbrian Facility/University of Manchester, UK

A major challenge in developing new materials for nuclear applications, or extending the life span of materials in existing nuclear plant, is understanding how these materials behave in the intense radiation fields they will be subjected to during their lifetime.

The University of Manchester's Dalton Cumbrian Facility has been recently established to undertake accelerated radiation damage experiments into a wide range of materials of relevance throughout the nuclear fuel cycle. A major aspect of the facilities on offer to researchers are a pair of ion beam particle accelerators, capable of delivering intense beams of a wide range of ions. These include protons, alpha particles and high energy heavy ions.

End station capabilities allow for samples to be irradiated under conditions reflecting those observed under operating reactor conditions such as elevated temperatures (up to 600 degrees Celsius). We are also developing the capability to simultaneously irradiate materials in contact with high pressure liquid environments.

P11. UK nuclear data network

P Davies


The UK Nuclear Data Network is a new initiative between UK universities, national laboratories, and industry. The aim of UKNDN is to develop nuclear data measurements for energy production by providing funding for experimental work and training. The poster will provide an outline of the current experiment interests of the network, training activities and highlight opportunities for funding.

P12. Strain localisation in proton irradiated zircaloy-4 measured using digital image correlation

R Thomas1, D Lunt1, M Atkinson1, J Quinta da Fonseca1, M Preuss1, J O’Hanlon2, F Barton2 and P Frankel1 1University of Manchester, UK, 2Rolls-Royce plc, UK

Zirconium alloys are used by the nuclear industry as fuel cladding in light water reactors due to their low neutron absorption cross section, good mechanical strength and corrosion resistance at elevated temperature. The demanding conditions encountered in service cause a variety of microstructural changes to occur which can have a detrimental effect on material properties [1]. During operation, defects known as dislocation loops form in the alloy as a result of neutron bombardement [2,3]. Macroscopically, these cause mechanical strength to increase and ductility to decrease because the dislocations act as obstacles to deformation. However, when a sufficient stress is applied, thin channels free of defects are formed (shown in Figure 1) which act as preferred sites for further deformation resulting in very large local strain [3].

Examining fuel assemblies in service is not feasible and replacement due to failure is expensive. Therefore, to maintain safe and economic operation, the design life of components must be accurately determined. New techniques which allow damage localisation to be studied experimentally before failure, are key to developing a better understanding of the the effect of operating conditions on deformation mechanisms. One such technique, High-Resolution Digital Image Correlation (HRDIC) can be used to quantitatively measure

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the inplane displacement field and thus generate nanoscale resolution strain maps suitable for studying local deformation.

Figure 1. TEM micrograph of propagating basal dislocation channel in neutron irradiated Zircaloy-4 at 0.36% elongation [3].

Due to residual sample activation produced during neutron irradiation, handling of such samples can prove time consuming and expensive [4]. As a result, this work utilises proton irradiation at the Dalton Cumbrian Facility, which produces minimal sample activation and has been shown to induce similar amounts of radiation induced material changes, provided a higher irradiation temperature is used [4]. Following irradiation of a Zircaloy-4 sample with protons to 0.15 displacements per atom, uniaxial tensile deformation to a macroscopic strain of around 2% was carried out. Using HRDIC, maps of effective shear strain were generated for the non-irradiated region (Figure 2a) and the irradiated region (Figure 2b). Fine, diffuse slip bands are visible in the non-irradiated region while the irradiated region shows intense heterogeneous slip. By correlating the strain field data with grain orientation obtained with EBSD, single grains are isolated allowing further analysis to be carried out.

Figure 2. Effective shear strain maps of a) nonirradiated and b) irradiated region in a Zirconium sample. White lines denote grain boundaries.

[1] R. Krishnan, M.K. Asundi, Zirconium alloys in nuclear technology, Proc. Indian Acad. Sci. Sect. C Eng. Sci. 4 (1981) 41–56.

[2] F. Onimus, J.L. Béchade, C. Duguay, D. Gilbon, P. Pilvin, Investigation of neutron radiation effects on the mechanical behavior of recrystallized zirconium alloys, J. Nucl. Mater. 358 (2006) 176–189.

[3] F. Onimus, I. Monnet, J.L. Béchade, C. Prioul, P. Pilvin, A statistical TEM investigation of dislocation channeling mechanism in neutron irradiated zirconium alloys, J. Nucl. Mater. 328 (2004) 165–179.

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[4] G.S. Was, J.T. Busby, T. Allen, E.A. Kenik, A. Jensson, S.M. Bruemmer, J. Gan, A.D. Edwards, P.M. Scott, P.L. Andreson, Emulation of neutron irradiation effects with protons: Validation of principle, J. Nucl. Mater. 300 (2002) 198–216.

P13. Multiple cascade radiation damage simulations of pyrochlores

A Archer1, H R Foxhall2, N L Allan1, J Shearer1, D S D Gunn3, J H Harding2, I T Todorov3, I Scivetti3, K P Travis2

and J A Purton3 1University of Bristol, UK, 2University of Sheffield, UK, 3 STFC, UK

We report molecular dynamics simulations of multiple radiation damage cascades in the pyrochlores Gd2Ti2O7 and Gd2Zr2O7 and in the solid solution Gd2(ZrxTi1-x)2O7 (x = 0.0, 0.25, 0.50, 0.75, 1.0). Using a simulation cell of approximately 360,000 atoms, for each compound 2,200 decay events are simulated over a total time of 10 ns. The structures generated in the simulations are analysed using Steinhardt local order parameters. There is a large increase in volume for the Ti pyrochlore associated with a transition to an amorphous structure which resembles the melt while preserving the immediate local environment of the Ti. The calculated dose for amorphisation is approximately 20 eV atom-1 which compares well with experiment. It appears to be the overlap of cascade and damage accumulation that drive the amorphisation and eventually suppress the healing mechanisms. We have examined the variation in amorphous fraction with the number of decay events - an expression with two rather than one exponential terms reproduces the simulation data well.

The behaviour of the zirconate is quite different – the substantial anion disorder produced by each recoil event is followed by substantial healing between cascade events and reversion to the parent pyrochlore. In the solid solution the onset of amorphisation is delayed to successively later times on increasing the Zr concentration and the overall swelling reduced. Our simulations highlight the importance of ion mobility, associated with the weaker Zr-O bonds, in the healing process.

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P14. Characterisation of redundant multi-element bottles using the multi-element bottle residual activity measurement method

A Callaghan

Sellafeld Ltd, UK

The Sellafield fuel storage pond system contains several hundred empty stainless steel Multi-Element Bottles (MEBs) previously used for transport and storage of LWR fuel pending reprocessing. These MEBs require to be disposed of for pond management purposes.

Figure 1. Multi-Element Bottles in pond storage

To allow removal of the MEBs from the pond and potential disposal off-site, a measurement of the residual internal activity and maximum point dose rate is required to demonstrate compliance with a number of Transport Regulations and Waste Acceptance Criteria. This MEB Residual Activity Measurement is known as the MEBRAM method

Figure 2. Multi-Element Bottle with 14 empty fuel channels

The residual activity of the MEBs arises from corrosion products in the reactor cooling systems adhering to fuel assemblies and deposited as crud in the MEBs during transport and storage of the fuel. The measured gamma dose rate in the crud is predominantly due to 60Co. Dose rate profiles are typically highest at the

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channel base dropping to lower levels on the channel walls. The dose rates gathered are converted to an activity value for 60Co and a fingerprint is used to determine the activity of all other nuclides prior to considering the MEB for consignment.

Figure 3. Dose rate profile

More than 500 LLW MEBs have been successfully removed from the pond using the MEBRAM method. Of these, more than 300 have been disposed of with a significant proportion of the MEB material recycled via a supply chain metals recycling facility. It is planned that the MEBRAM method will be adapted to apply to other redundant container types for future management of pond furniture stocks.

P15. Neutron-gamma imaging with compton camera and coded aperture

H Al Hamrashdi, S Monk and D Cheneler

Lancaster University, UK

Many fields in the nuclear industry utilize imaging systems that only detect a single type of particles, i.e. neutrons or gammas. However, there are many instances where it is recommended or even necessary to detect neutrons and gammas simultaneously. In these instances, a dual particle imaging system can offer a practical solution. However, there is often a trade-off between efficiency and spatial resolution in existing dual particle imaging systems. This trade-off often limits the efficacy of these systems in real applications. This Ph.D. study aims in designing a neutron-gamma imaging system that combines two existing imaging techniques; Compton camera and coded aperture camera. The combining of these two imaging techniques is expected to boost the performance of conventional dual particle imaging systems and at the same time overcome the low efficiency and/or poor resolution problems.

The main goal of this proof-of-concept study is to design a system that is capable of detecting simultaneously neutron and gamma ray sources with high efficiency and high spatial resolution. The provisional design is based on a three layers of scintillation detectors. The plan is to complete this proof-of-concept design through three main stages. The first stage will be devoted in studying each layer individually. That is to test different scintillation materials and different material thicknesses. In the second stage, an optimum three-layer design will be investigated. Finally, the design will hopefully be experimentally tested. Once the third stage is completed, the effect of data reconstruction methods on the image quality will be studied.

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