Corporate report

Direct Research Portfolio Annual Report 2019 to 2020

Published 21 September 2021

Introduction

The Nuclear Decommissioning Authority (NDA) is responsible for cleaning up the legacy from the UK's pioneering post-war nuclear programme.

From the late 1940s onwards, the country's smartest scientists and engineers led the world with ground-breaking nuclear discoveries. The result was a diverse range of experimental facilities and early nuclear power stations, designed initially for the UK's defences but later to provide electricity for its citizens.

Their work spanned 17 locations across the UK and included:

• Dozens of prototype reactors
• 11 nuclear power stations
• Scores of research labs
• Fuel-manufacturing and enrichment facilities
• Spent fuel reprocessing plants

Many of the designs were unique, producing radioactive wastes and spent fuel that no-one had ever dealt with before. Structures, pipework, container vessels and land became contaminated and were mostly left for a future generation to clean up.

Many years later, the NDA is dismantling this historical legacy, demolishing structures and preparing sites for future uses. The mission will stretch for another 100-plus years and cost more than £120 billion.

Dealing with such a range of complexities and uncertainties requires fundamental science, innovative thinking and novel engineering. Progress depends on clearly understanding the problems, finding solutions and ensuring the cost for taxpayers remains acceptable. Research & Development (R&D) is therefore an essential part of decommissioning programme. The aim is to solve the challenging technical problems more effectively, more efficiently, more safely and, where possible, for less cost.

A total of approximately £86 million was spent on R&D during 2019 to 2020 by the NDA group.

The bulk of this forms part of the budget allocated to our Site Licence Companies and subsidiary organisations, and is aimed at addressing specific on-site challenges identified during decommissioning activities. The work is carried out by SLCs, the subsidiaries and through contracts awarded to their supply chain.

Separately, the NDA also retains a strategic portfolio to commission projects directly, particularly in areas with potential to have an impact across a number of sites, or to develop our overall strategy. This kind of research may help shape and develop our strategy, encourage early innovation or maintain key technical skills.

About the DRP

The Direct Research Portfolio (DRP) is a key component of the NDA's R&D programme. It accounts for approximately £4 million of our annual investment and represents an important area of overall support for R&D across the group's 17 sites and subsidiary organisations.

The DRP is made up of projects that:

• Help shape and underpin the NDA's overall strategy for the UK
• Deliver innovation across multiple sites
• Develop vital technical expertise for the future,

DRP projects are aligned against the NDA's 4 driving strategic themes:

1. Integrated waste management
2. Site decommissioning and remediation
3. Spent fuel management
4. Nuclear materials

DRP projects are commissioned through framework contracts that last up to 4 years. The contracts, awarded from 2016-2020, involve 3 framework contracts:

Lot A: University interactions

Lot B: Integrated waste management plus site decommissioning and remediation

Lot C: Spent fuel management and nuclear materials

Overall, 10 consortia are involved in the DRP, comprising around 70 organisations ranging from UK universities and research bodies to global corporations and small businesses.

Topics for individual projects are identified either by the NDA's internal technical experts or through members of the Nuclear Waste and Decommissioning Research Forum (NWDRF), a cross-industry forum which promotes collaboration across the UK on nuclear decommissioning R&D.

This report outlines a number of projects funded through the DRP during 2019 to 2020. Some are ongoing from earlier contracts, but all have potential for a significant impact across the group.

Total investment in the DRP over the financial year was £3.9 million.

Further information on NDA's R&D programme can be found in our 5-year R&D plan.

DRP spend

£3.9million spent during 2019 to 2020

2019 to 2020 spending breakdown

Framework Contract	2019 to 2020 Spend
University Interactions	£2.2 million
Integrated Waste Management & Site Decommissioning and Remediation	£0.6 million
Spent Fuel & Nuclear Materials	£1.1 million

New DRP projects in 2019 to 2020 by NDA R&D driver

NDA R&D Driver	Number of new projects (2019 to 2020)
Delivering innovation	5
Inform strategy	21
Maintaining skills	24

Note: Some DRP research projects have multiple drivers

University interactions

New PhDs funded during 2019 to 2020

PhD title	University	R&D Driver
Thermal Modelling of AGR Fuel Drying	University of Bristol	Maintaining Skills
Learning from historical cement sample stores	University of Sheffield	Maintaining Skills
Development of efficient interference suppression for ICP-MS to enable rapid 90Sr detection	University of Manchester	Maintaining Skills
Monitoring Sr90 with Anti-Neutrinos	University of Liverpool	Maintaining Skills
Imaging and Nuclear Waste Characterisation using laser plasma accelerators	University of Strathclyde	Maintaining Skills
Detection and characterisation of multi-radiation sources in the characterisation of nuclear facilities	Glasgow University	Maintaining Skills
Benchmarking to reduce budget uncertainty & actual cost, and increase learning from Oil & Gas	University of Leeds	Maintaining Skills
Developing a resilience framework for decommissioning plan of a nuclear facility	University of Strathclyde	Maintaining Skills
Colloidal Silica Grout for Stabilisation of Underground Structures and for the Formation of Hydraulic and Chemical Barriers for Inhibiting Contaminant Migration	University of Strathclyde	Maintaining Skills

New Trancend PhDs funded during 2019 to 2020

The Recombination of Hydrogen and Oxygen on Metal Oxide Surfaces	Lancaster University	Maintaining Skills
Characterisation of thermal treatment products	University of Sheffield	Maintaining Skills
Process monitoring of thermal treatment of nuclear wastes	Sheffield Hallam University	Maintaining Skills
Predicting Gamma Dose Rates based on Limited Information	University of Surrey	Maintaining Skills
Computational Modelling of PuO2: Ageing and Storage Phenomena	Birmingham University	Maintaining Skills
Characterisation of perforated AGR fuel and its behaviour during drying	University of Leeds	Maintaining Skills

*Other supporting activities include providing academic access for students to NNL facilities, industrial supervision for students and conducting impact analyses (value scorecard) of NDA funded university projects.

Integrated waste management & site decommissioning and remediation

New projects started during 2019 to 2020

Project Name	Lead Organisation	R&D Driver
Feasibility of Techniques for the management of Radiologically Contaminated Mercury	Eden	Inform Strategy & Deliver Innovation
Exploring the use of blending, mixing, dilution or averaging in the management of radioactive wastes.	Eden	Inform Strategy
Remote Visual Inspection (RVI) HSE &NDA Research Programme	HSE	Deliver Innovation
Evolution of C14 containing wasteforms - Near Surface	Wood	Inform Strategy
Disposability of Nochar absorbed higher activity wastes: combustibility trials	NSG Environment	Inform Strategy, Deliver Innovation & Maintaining Skills

*Other supporting activities include principle membership of the CL:AIRE sustainable land reuse group.

Spent fuel management and nuclear materials

New projects started during 2019 to 2020

Project Name	Lead Organisation	R&D Driver
Assessing the Risk of Helium Pressurisation Impacting on SNM Disposition	NNL	Inform Strategy & Maintaining Skills
Review of analytical capabilities to carry out specialist Pu analysis in UK and overseas and development of a small scale research sample preparation and management service to carry out that work.	NNL	Inform Strategy
Electrochemical model for AGR cladding relevant to long-term pond storage	Wood	Inform Strategy
Desk Top review of Powder Granulation Options for a HIP based Plutonium Immobilisation Process (10973)	NNL	Inform Strategy & Maintaining Skills
Inactive Trials of Flash Sintering on Simulated Plutonium Wasteforms	Wood	Inform Strategy
Investigation of Propensity for Zircaloy to undergo corrosion in chloride solution and contact with mild steel	Wood	Inform Strategy
Update on Applicability of Fast Reactor Technology for Pu Disposition paper.	Wood	Inform Strategy & Maintaining Skills
PSE Work following Fuel Receipt	NNL	Inform Strategy & Maintaining Skills
Improving the capability of the current speciation model to support spent fuel monitoring of heterogeneous fuel types and storage systems	NNL	Inform Strategy
Desktop Review of the Optimisation of MOX Fuel for Disposal	Wood	Inform Strategy
Review of Data and Info available to support disposal of Unirradiated MOX Fuel in a UK GDF	Wood	Inform Strategy
Desktop Assessment of Storing Product Powder Inside Spend Fuel Casks	Wood	Inform Strategy
Online test to explore Neutron Tomography detecting water in AGR & exotic fuels	Orano	Inform Strategy, Deliver Innovation & Maintaining Skills
Desktop Review of Plutonium Simulants for Wasteform Process Development	NNL	Inform Strategy, Deliver Innovation & Maintaining Skills
First Step towards the development of a fuel drying model for AGR - Phase 1	Wood	Inform Strategy
WP_LC_46 In-active Trials of the Fabrication & Leach Testing of Simulated Plutonium Wasteforms incorporating Neutron Poisons.	Wood	Inform Strategy & Maintaining Skills
WP_LC_46 In-active Trials of the Fabrication & Leach Testing of Simulated Plutonium Wasteforms incorporating Neutron Poisons.	NNL	Inform Strategy & Maintaining Skills

*Other supporting activities include preparation and attendances at forums and meetings such as the 2019 AGR Forum and US National Lab meeting on Pu-active analytical equipment.

Case studies

Discharge Pipelines

By providing funding and support to an array of university research programmes, students contribute to the NDA mission by developing our knowledge on specific decommissioning challenges. Through researching and developing their skill set, students enhance their potential to become integral members of the nuclear industry in the future.

Framework contract: University interactions

Challenge: To further understand the effects that scaling can have in radioactive discharge pipelines.

Solution: Collaborate with industry and construct experimental rigs to investigate scaling formation and its characteristics.

Benefits: Increase understanding of scaling behaviour and how scaling can impact effluent discharge and pipe corrosion. Subsequently, this research will provide greater underpinning when it comes to decommissioning the pipelines.

Status: Ongoing (scheduled to be complete in 2022)

R&D driver: Maintaining Skills

Research organisations: University of Manchester

Details: Many of the nuclear sites across the UK feature radioactive discharge pipelines which can be hard to access as they may be buried under private land and terminate a significant distance offshore. Scaling can occur in these pipes where radioactive, chemical or biological substances become associated with the pipe structure itself. Scaling can affect the control of effluent flow through the pipelines, enhance corrosion of the pipes themselves and become a challenge during subsequent decommissioning operations.

Franky Barton, a PhD student at the University of Manchester, is investigating the scaling phenomena using a range of approaches. Working closely with technical leads from Magnox, she has obtained samples of real scales from the Winfrith site in Dorset and analysed these materials using electron microscopy and x-ray mapping. Franky has also built some experimental rigs to simulate discharge pipe conditions and replicate the formation of both inorganic and biological scales in the laboratory. The biofilms she has grown in the lab, based on the Shewanella bacteria, are also being doped with clinoptilolite fines to reproduce scaling behaviour observed at the Sellafield site.

Franky is quoted as saying:

I have really enjoyed my NDA-funded PhD so far, especially the mix of academia and industry. On the academic side, the multidisciplinary nature of the project has been a real bonus as I’ve been able to explore multiple fields including biology, geochemistry, mineralogy and radiochemistry, and ultimately use a wide range of characterisation techniques. I find the industrial focus of the PhD and the potential impact of the findings on real life challenges faced in decommissioning really motivating. Working closely with industrial professionals from various sites, for arranging a sampling programme for example, has also been a great aspect to the PhD.

The work that Franky is doing will help us to develop our fundamental understanding of scaling behaviour in discharge pipelines. Her regular interaction with technical contacts from the NDA group, as well as her industrial supervisor from the National Nuclear Lab, ensures that her research is targeted at the pertinent areas and that the knowledge she is creating is transferred back into the industry. This will ultimately influence the strategies that we develop to manage and decommission the pipelines.

Rick Short, manager of the NDA’s academic research portfolio, said:

Through her experimental studies using uranic compounds, Franky is developing the academic capability in the UK to work with active materials as well as building a skill set that could ultimately make her a valuable contributor to the decommissioning workforce or our supply chain. It is a testament to the quality of her work that she was recently awarded the best speaker prize at the annual NDA PhD Bursary Seminar.

Good Practice Guides

Given the heterogeneity of radioactive waste arising from all the NDA's 17 sites, mixing different radioactive and non-radioactive wastes can help manage the wastes safely and securely whilst ensuring the protection of people and the environment. This project seeks to establish some guiding principles to be used as a foundation for the development of consistent, optimised radioactive waste mixing practices and provide an underlying basis for judgements.

Framework contract: Integrated Waste Management

Challenge: To enable more consistent, acceptable radioactive waste mixing practices and provide an underpinned basis for judgements.

Solution: Establish a set of guiding principles for mixing in the management of radioactive wastes based on industry practice, policy, and strategic drivers.

Benefits: The principles will promote an increased confidence and consistency across the nuclear industry, ultimately enabling optimised waste management to be realised.

Status: Completed and implemented across the group.

R&D driver: Inform Strategy

Research organisations: Eden Nuclear and Environment Ltd

Details: Combining different radioactive wastes (and non-radioactive wastes) can reduce the overall radioactivity and assist in effectively managing the waste. Policy, regulatory and strategic drivers can often induce an element of subjectivity for the acceptability of mixing during radioactive waste management.

Therefore, to provide clarity and promote a more consistent approach across the industry, Eden have collaborated with the NDA to generate a set of guiding principles based on current industry practices benchmarked against current policy, regulatory and strategic drivers.

Eden developed the guiding principles using a consultative approach that reviewed current practices within the nuclear industry. A combination of questionnaires and discussions were used to identify acceptable and unacceptable mixing practices, and in particular, to recognise any disparities within or between organisations.

Subsequently, case studies were developed with interested stakeholders in a workshop organised by Eden. The outcomes of the initial consultation and workshops culminated in a set of guiding principles that were reviewed and finalised amongst stakeholders.

The guiding principles covered the following:

• Government policy and strategy alignment
• Ensuring an optimised approach
• Regulatory compliance
• Compliance with waste acceptance criteria
• Physical and chemical compatibility of mixed wastes
• Mixing and waste conditioning

The guiding principles reflect the current policy, regulatory and strategy landscape at the time of publication. They will require updating in response to any changes that could affect the validity of the principles.

These guiding principles seek to provide a common and systematic framework to ensure optimised waste management practices. A consistent optimised approach will ensure that best available techniques are being adhered to and help reduce the cost for the taxpayer.

Carbon-14

Carbon-14 is a key radionuclide in the assessment of disposal facilities for radioactive waste. The ILW waste streams that contain carbon-14 (which include large quantities of reactor graphite) may constrain the volumes of these materials that can be disposed of at disposal facilities. A review of the behaviour and release mechanisms of carbon-14 has been carried out to support a source term model to predict the release of carbon-14 into the environment.

Framework contract: Integrated Waste Management

Challenge: To understand the evolution of carbon-14 containing wastes in support of our lifecycle management strategies of these wastes.

Solution: Review the current scientific knowledge on the behaviour of waste and develop a model to predict the release of carbon-14.

Benefits: Greater certainty in the release mechanisms and evolution of carbon-14 containing wastes underpinning our post-closure safety assessments and carbon-14 capacity of existing and future disposal facilities.

Status: A detailed overview has been completed with recommendations for further work to address gaps in scientific knowledge.

R&D driver: Informing Strategy

Research organisations: Jacobs

Details: As the UK approaches the next steps of decommissioning its civil nuclear sites, disposing of the radioactive wastes that will be generated is key in ensuring the safety and security to the public and the environment. Carbon-14 is a key radionuclide in the post-closure safety assessments of disposal facilities. Many large volume waste streams, such as reactor core graphite, contain high concentrations of carbon-14. Understanding the behaviour of the long-lived carbon-14 radionuclide in these wastes, and its evolution, is critical in evaluating the post-closure safety assessments and capacity limits of carbon-14 containing wastes.

The NDA commissioned research to further our understanding of carbon-14 release mechanisms from wastes reported in the UK Radioactive Waste Inventory (UKRWI) and its evolution in disposal facilities. Jacobs undertook this research reviewing the current scientific knowledge base and developing a model to predict carbon-14 release in disposal environments.

The first deliverable provided a detailed review of carbon-14 release processes from materials containing carbon-14 identified for disposal (e.g. irradiated graphite, concrete and spent ion exchange resins (SIER) to name a few).

This data provided the scientific basis for the second deliverable. A simple model predicted carbon-14 release from disposal facilities via the gas and groundwater pathways. The SMOGG (Simplified Model of Gas Generation) tool, previously developed for Radioactive Waste Management Limited (RWM), was used to model the release of carbon-14 from wastes.

The final deliverable focussed on formulating a research plan to address the gaps in scientific knowledge. Ten knowledge gaps were identified and consequently prioritised between representatives from the NDA, RWM, Low Level Waste Repository Ltd and Jacobs.

The results from these pieces of work give a comprehensive outline of the possible carbon-14 release mechanisms in waste. Post-closure safety assessments and increased confidence in predicting carbon-14 release are just a selection of the benefits.

Water Detection

The current management strategy for the majority of spent fuel is wet storage. Prior to disposal, the fuel will have to be removed from wet storage and dried to expel any residual water. The presence of residual water in fuel pins can increase the likelihood of pressurisation from radiolysis and corrosion of the containers. Therefore, neutron tomography has been identified as a technique that could be suitable for detecting and quantifying residual water content.

Framework contract: Spent Fuels

Challenge: To locate and quantify residual water in spent fuel to underpin disposal safety cases.

Solution: Undertake research and experiments to evaluate the technologies available for detecting water in spent fuel.

Benefits: Environmental good practice and an increased confidence in safety for dry storage/disposal of spent fuel.

Status: Technology still in early development with experimental trials to be undertaken.

R&D driver: Informing Strategy

Research organisations: Orano Projects Limited

Details: If the UK’s AGR and exotic fuel inventories are classified as waste, then final disposal to a Geological Disposal Facility (GDF) is planned to begin in approximately 2075. Currently, spent AGR fuel is kept in wet storage whilst a mix of wet and dry storage is employed for exotic fuels. Whether the fuel must be moved for further interim dry storage or final disposal, the fuel pins would require drying to remove any residual water. The presence of water can accelerate corrosion or increase the probability of pressurisation, therefore it is important to be able to detect and quantify the amount of residual water to understand the implications on its final disposal.

Neutron imaging techniques are common in the nuclear industry, primarily used for imaging nuclear fuels and identifying fuel defects. More specifically, neutron tomography aims to distinguish between different densities and materials within an object. The NDA have identified this as a potentially suitable technique that could enable detection and quantification of water content in fuel pins.

Orano utilised the supply chain in this project, drawing upon expertise from a range of organisations such as NSG Environmental, Mirion Technologies and Hybrid Instruments. This facilitates the sharing of information and promotes knowledge transfer throughout the supply chain.

The study constituted of three phases of work including:

• A literature review assessing the options of fuel that could be investigated with neutron tomography.
• Simulations using the Monte Carlo N-Particle program to inform the viability of potential neutron tomography set-ups.
• A desk-based study to outline non-active trials for demonstrating the feasibility of an experimental set-up.

Three specific fuel types were selected from the literature review for further investigation, including spent AGR fuels. The subsequent Monte Carlo N-Particle simulations showed that there is potential to identify water quantities between 100-200g, however, this was highly dependent on the location of the water. Following the simulations, Orano proposed the requirements (including equipment and fuel simulants) to conduct inactive trials to test the feasibility of neutron tomography in detecting water.

Overall, there was the conclusion that neutron tomography is a promising option. It was noted however, that additional experimental work would be needed to underpin this technique and future work with simulations would be beneficial.

Plutonium Disposal

The NDA is actively researching technologies for the immobilisation of plutonium to underpin our advice given to support government decisions. 'Unirradiated' Disposal MOX fuel is an option being considered amongst others. Disposal MOX offers advantages due to our previous manufacturing experience with MOX fuel and with it being a 'fresh' wasteform. Therefore, the typical effects seen in spent fuel are curtailed.

Framework contract: Nuclear Materials

Challenge: To identify an effective method for disposing of plutonium safely, securely and cost effectively.

Solution: Investigations into a range of technologies to assess their suitability.

Benefits: Consolidation and stabilisation of plutonium for long-term storage.

Status: Technologies currently being investigated at different TRLs.

R&D driver: Informing Strategy

Research organisations: Jacobs (formerly Wood)

Details: At the end of reprocessing the UK will have accumulated an inventory of around 140 tonnes of separated civil plutonium. The NDA is currently researching options to manage this material which include, re-use as MOX fuel or immobilisation in ceramic wasteforms. One potential ceramic wasteform under consideration is disposing of unirradiated MOX fuel (Disposal MOX).

Plutonium disposition is one of the most complex projects facing the NDA. Therefore, it is imperative that the NDA assess all options comprehensively in order to provide the technical underpinning information to support future government decisions on disposition.

One advantage of disposal MOX is that the fabrication technology is now considered to be mature. Disposal MOX is manufactured in a similar procedure to regular MOX fuel by mixing uranium and plutonium powders into pellets using a cold press and sinter process. Another advantage is that some credit can be taken for existing studies on the disposability of spent fuel, including spent MOX fuel, noting that typical effects observed in spent fuel, such as crack formation and pellet-cladding interaction, are absent.

Jacobs (formerly Wood) have undertaken projects reviewing the data to support and optimise MOX fuel for disposal. Optimisation parameters such as size, geometry, density and neutron poisons have all been reviewed using a combination of literature reviews and experimental procedures. The exploratory work concluded that there is scope for further work to constrain the parameters to support the development of an optimised disposal MOX product.

Further work by Jacobs has reviewed the durability of disposal MOX in a GDF. The review focused on wasteforms including spent fuel (particularly MOX fuels) and other Pu-wasteforms (eg. Zirconalites) due to the current lack of available information for disposal MOX.

Collaborating with Brenk, Julich and the University of Cambridge for this project has ensured that the right expertise is tapped into and that the best value is guaranteed for the taxpayer. The outcome of all the research will be examined when the NDA provides advice to government on options for plutonium disposition. The government’s final policy decision will consider a wide range of factors including technical feasibility, security issues, costs and benefits.

DRP framework contractors

University interactions

Lead Organisation	Consortia
National Nuclear Laboratory	Frazer-Nash Consulting

Integrated waste management and site decommissioning and remediation

Lead Organisation	Consortia
Wood	Brenk Systemplanung, Jülich Research Centre, Andra, Cogentus Consulting, DAS, Imperial College London, Longenecker & Associates, MMI Engineering, NuVision, OC Robotics, Fortum, University of Birmingham, University of Bristol, University of Cambridge, University of Manchester
Arcadis	AdvanSci, Applied Photonics, Areva RMC, Aurora, ESI, MDecon, Pöyry, ProNu-Dec, Tradebe Inutec, TWI, University of Liverpool, Dalton Nuclear Institute, University of Surrey
Arup	Costain, Pöyry, Studsvik, James Fisher Nuclear, SN3, AdvanSci, MCM, Bilfinger GVA, Pinsent Masons, CL:AIRE, r3 Environmental Technology, Dalton Nuclear Institute
Eden Nuclear and Environment	Cavendish Nuclear, DBE TECHNOLOGY GmbH, Golder Associates, Tradebe Inutec, Project Time and Cost International
Galson Sciences	National Nuclear Laboratory, Frazer-Nash Consulting, Advansci, Amphos 21, Cogentus Consulting, Integrated Decision Management, Jacobs, Kurion, Rodgers Leask, VTT, University of Bristol, Lancaster University, University of Leeds, University of Manchester, University of Sheffield
NSG Environmental	AECOM, ARC, Oxford Technologies, NPL, ESG, Quintessa, React Engineering, KDC, Tradebe Inutec, Synergy Health, Nuclear AMRC, Loughborough University, University of Manchester, University of Surrey

Spent fuel management and nuclear materials

Lead Organisation	Consortia
Wood	Andra, Brenk Systemplanung, Jülich Research Centre, Imperial College, DAS Ltd, Fortum, MMI Engineering, NPL, NRG, OC Robotics, Studsvik, University of Birmingham, University of Manchester, University of Bristol, University of Cambridge, Loughborough University
Orano	NSG Consultancy, MDecon, Quintessa, University of Liverpool, University of Sheffield
National Nuclear Laboratory	Frazer-Nash Consulting, Galson Sciences, ALD France, Aquila Nuclear Engineering, DBD, DAS, IDM, Jacobs, Kurion, Rodgers-Leask, University of Bristol, Lancaster University, University of Leeds, University of Manchester, University of Sheffield, Imperial College