HADES: A User Facility for High Activity Decommissioning Engineering Science

Lead Research Organisation: University of Sheffield
Department Name: Materials Science and Engineering

Abstract

HM Government's civil nuclear energy policy has the threefold objectives of: exploiting nuclear power for low carbon, reliable and affordable electricity generation; decommissioning the legacy of historic nuclear fuel cycle activities; and safe disposal of radioactive wastes. Building on the Nuclear Industrial Strategy, the Nuclear Sector Deal set the vision for the civil nuclear sector, to deliver by 2030:
* 30% cost reduction in cost of new build projects
* Savings of 20% in cost of decommissioning compared with current estimates
* Up to £2bn domestic and international contract wins
The HADES Facility for High Active Decommissioning Engineering Science aims to play a pivotal role in realisation of these objectives through investment of a suite of equipment to enable fundamental and applied research in thermal treatment of radioactive wastes. Such technology utilises the application of heat to immobilise radionuclides and chemotoxic species within a passively safe product (a glass, slag or ceramic) suitable for interim storage and disposal. The benefits afforded by this approach are potentially game changing and include radical volume reduction and elimination of waste reactivity and organic inventory. The estimated lifecycle cost savings arising from successful implementation of thermal treatment technology in legacy nuclear decommissioning programmes are £billions in each of the UK and USA. Thermal treatment of radioactive wastes from future advanced recycle of nuclear fuels will reduce the environmental footprint of future nuclear generation, and reduce the associated waste management cost, through development of next generation materials for high level waste immobilisation, which are compatible with the challenging characteristics of such wastes and achieve a greater efficiency of waste incorporation. The technological developments achieved in these domains will realise new intellectual property and highly skilled human capital to grow the UK share of the legacy and future nuclear decommissioning market.
The HADES Facility, the only one of its kind in the UK, will enable this impact to be realised by creating unique infrastructure to handle large radioactive inventories and real radioactive wastes at the laboratory scale, to develop waveform formulation, process envelope, and product disposability to advance thermal treatment technology and enable timely implementation by current and future site licence companies. In so doing, we will nucleate grow a world leading community of practice, producing highly skilled user-researchers, through effective training and networking activities. Additionally, the unique capability established within the HADES Facility will be a beacon to attract and engage international collaboration, enabling us to pool research resources to address trans-national challenges in radioactive waste management and extending the reach of impact from the arising research beyond the UK.

Planned Impact

The HADES Facility will be unique in the UK with its capability to enable thermal treatment research with high inventories of radionuclides. The Facility will be capable of addressing a diverse range radioactive waste management challenges relevant to decommissioning of UK and international nuclear sites. In summary, we therefore focus on three areas of immediate impact, each associated with a Sheffield led research projects with EPSRC and industrial support, although we have identified a considerable UK and international user base who could exploit the facility capability to advance their own research programmes.
1) Maturation of hot isostatic pressing technology to immobilise UK plutonium stockpile and residues and high dose spent adsorbents. HM Government has placed renewed focus on management of the plutonium stockpile, for which immobilisation of at least 5tHM is likely to be required. Upgrade of our existing Hot Isostatic Press with an Active Furnace Isolation Chamber and control system, will allow systematic investigation of ceramic and glass-ceramic formulations utilising U and effective Pu surrogate and optimisation of process envelopes. Translation of the research outcomes enabled by the Facility infrastructure, through effective collaboration with the National Nuclear Laboratory, Sellafield Ltd., and Nuclear Decommissioning Authority, will contribute to the evidence base required to inform HM Government decision on plutonium immobilisation and an investment in a waste treatment complex. This research, which cannot currently be undertaken at any other UK facility, is timely and has the potential to address one of the highest priority challenges on the Sellafield site, from the perspective of both research outcomes and the operational experience of radiological HIP application. This work is supported by several EPSRC grant
2) Thermal treatment is one potential treatment option for spent ion exchange resins which pose a challenge to low level waste disposal, for example, due to incorporated complexants (e.g. EDTA). We are developing proof of the efficacy of thermal treatment to such wastes, which results in destruction of the complexant species and incorporation of the radionuclide inventory into a compatible glass matrix. The proposed equipment investment will support future laboratory scale development of this approach utilising real radioactive resin wastes supplied by MOD, to understand the impact of radiolytic degradation of resin on the process envelope, evolved off gas, and product quality. MOD, are undertaking a Best Practicable Environmental Option assessment for these wastes, to reduce onsite hazard in line with regulator advice. Thus, our planned research, enabled by the Facility, will be opportune because the outcomes will arise during a key window of strategy development to allow uptake by MOD to refine their waste management strategy and potentially open the first route for vitrified resin disposal at LLWR. The research outcomes will also be of interest to other waste producers.
3) The NDA Research Board has highlighted the need to "ensure that thermally treated products meet the acceptability criteria for disposal" as being of "fundamental importance" so that "disposability does not become a "show stopper" at a late stage". The RWM Science & Technology Plan specifies the knowledge gaps that need to be addressed in this regard, which focus on understanding the mechanisms of plutonium (glass)-ceramics and vitrified ILW glass dissolution, and interaction with engineered back fill materials, in conceptual disposal concepts; note, also there still remain knowledge gaps concerning the fundamental mechanisms of HLW glass corrosion. The proposed equipment investment will enable the UK research community to address these challenges by enabling preparation and characterisation of conceptual wasteforms, incorporating key radioactive elements (U, Tc), for mechanistic dissolution studies.

Publications

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Bailey D (2020) Ce and U speciation in wasteforms for thermal treatment of plutonium bearing wastes, probed by L 3 edge XANES in IOP Conference Series: Materials Science and Engineering

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Blackburn L (2020) Hot Isostatically Pressed Zirconolite Wasteforms for Actinide Immobilisation in IOP Conference Series: Materials Science and Engineering

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Cascos VA (2020) Tuning between Proper and Hybrid-Improper Mechanisms for Polar Behavior in CsLn 2Ti2NbO10 Dion-Jacobson Phases. in Chemistry of materials : a publication of the American Chemical Society

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Ding H (2020) Advanced Gas-cooled Reactor SIMFuel Fabricated by Hot Isostatic Pressing: a Feasibility Investigation in IOP Conference Series: Materials Science and Engineering

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Dixon Wilkins M (2020) Synthesis and characterisation of high ceramic fraction brannerite (UTi 2 O 6 ) glass-ceramic composites in IOP Conference Series: Materials Science and Engineering

 
Description The aim of this project is tol create new and critically important capability to support research and development of thermal treatment technologies for radioactive waste, within the HADES Facility for High Activity Decommissioning Engineering Science. Thus constituted, HADES will address the national requirement for capability in the "Development of Thermal Treatment of Radioactive Waste", as specified in the NNUF Call for Proposals. This will be achieved by the following approach, which will leverage £8M of investment in research infrastructure committed since 2014:
• Joint investment by EPSRC and the host organisation, will renew, enhance and extend equipment capability for thermal treatment of radioactive waste. Critically, this will substantially increase the ambition of research in this domain, enabling MBq ? or ??? inventories to be utilised, opening the door to work with real radioactive wastes.
• This EPSRC funded equipment will be integrated with the existing (DECC funded) low active MIDAS capability at the host organisation to deliver HADES as a consolidated facility to support materials science for nuclear decommissioning, waste management, and geological disposal; it will also be capable of supporting research across the wider nuclear fuel cycle (e.g. fuels development).
Progress toward realisation of the HADES Facility was severely impacted by the Covid 19 pandemic, which delayed the procurement, installation, and commissioning of equipment. Nevertheless, capital expenditure has proceeded to plan and the project is on track to have procured all equipment by the end of the second financial period. Commissioning use of sample preparation equipment and high temperature furnaces, along with instrumentation available through integration of the MIDAS facility has enabled the host research team to progress research across a broad research programme, albeit severely curtailed and delayed by restrictions on working arrangements. This research has generated 31 publications to date, of which the following are highlighted:
• A publication summarising the development, capability and equipment of the facility was published, as IOP Conf. Ser.: Mater. Sci. Eng. 818 012022, which formed the basis for a presentation at the joint THERAMIN 2020 Conference on Thermal Treatment of Radioactive Waste, 4-5 February 2020.
• Three publications in ACS Inorganic Chemistry, reporting the synthesis and characterisation of a new family of periodate ceramics for iodine immobilisation - Inorg. Chem. 59 (2020) 18407, the complex redox behaviour of CeTi2O6 ceramics for actinide immobilisation - Inorg. Chem. 59 (2020) 17364, and the structure of advanced phosphate cements determined by multinuclear solid state NMR, Inorg. Chem. 60 (2021) 195.
• Several publications on ceramics and glass ceramics for actinide immobilisation, utilising the U and Th handling, processing and analysis capabilities of the facility, including UTi2O6 glass ceramics - J. Nucl. Mater., 542 (2020) 152516, CaZr-1xThxTi2O7 ceramics - J. Am. Ceram. Soc., (2021) in press, and elucidation of the local structure of amorphous U2O7, J. Nucl. Mater., 542 (2020) 152476.
Exploitation Route The facility will be open to external users when complete and as permitted by national and local working restrictions. Thus, the full outcomes of the funding, in terms of the directly and indirectly supported equipment base will be available for use by the wider research community, as well as the specific research outcomes.
Sectors Chemicals,Energy,Environment,Government, Democracy and Justice

 
Description (PREDIS) - PRE-DISposal management of radioactive waste
Amount € 23,773,743 (EUR)
Funding ID 945098 
Organisation European Commission 
Sector Public
Country European Union (EU)
Start 09/2020 
End 08/2024
 
Description Improved glass formulations for advanced oxide fuels - Advanced Fuel Cycle Programme
Amount £120,000 (GBP)
Organisation Department for Business, Energy & Industrial Strategy 
Sector Public
Country United Kingdom
Start 07/2020 
End 06/2021
 
Description Pyrochemical Waste Treatment - Advanced Fuel Cycle Programme
Amount £120,000 (GBP)
Organisation Department for Business, Energy & Industrial Strategy 
Sector Public
Country United Kingdom
Start 07/2020 
End 06/2021
 
Description hermodynamics of caesium pertechnetate volatility - Advanced Fuel Cycle Programme
Amount £75,000 (GBP)
Organisation Department for Business, Energy & Industrial Strategy 
Sector Public
Country United Kingdom
Start 09/2020 
End 06/2021
 
Description Collaboration Workshop on Facilities for Materials and Environmental Radiochemistry Research 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A one day Collaboration Workshop on Facilities for Materials and Environmental Radiochemistry Research was held on 24th February 2020, to kick off development of the HADES project and showcase the NNUF 2 investment in this and the RADER and UTGARD facilities. The capability of the facilities was presented with a tour of the HADES facility. A workshop activity was also delivered to enable the user community to identify gaps in available capability for future development. One important gap identified by the community was the lack of facilities and fragile capability for studies of surrogate spent nuclear fuel disposal, which require rigorously anoxic glove box capability. This led to development and submission of the PLEIADES facility proposal to the NNUF2a call.
Year(s) Of Engagement Activity 2020
 
Description HADES Facility Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A one day open day was held on 6th February 2020, to showcase the HADES facility to potential national and international users and research collaborators. The event attracted 30 delegates who participated in tours of the facility and demonstrations of instrumentation and equipment. An overview presentation of facility equipment and capability was also provided. This event elicited expressions of interest in future use of the facility and collaboration from the delegates.
Year(s) Of Engagement Activity 2020
 
Description Joint Research Conference on Thermal Treatment of Radioactive Wastes with the EC THERAMIN Project 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The conference attracted more than 120 delegates from the UK, Europe and USA for a two day meeting (4 - 5th February 2020) on development of thermal treatment technology and its applications. The meeting renewed and established collaborative partnerships with several chimerical organisations, who expressed an interest in using the capability within the HADES facility.
Year(s) Of Engagement Activity 2020
 
Description Seminar series - Cloud Conference on Radioactive Waste Management 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A seminar series - Cloud Conference on Radioactive Waste Management, was organised immediately following the UK national lockdown in March 2020. Five seminars were held on a monthly basis attracting 70-100 participants on each occasion. Talks were drawn from across the UK research community, featuring early and mature research investigators from academia and industry, working within the broad area of radioactive waste management. Participants reported their appreciation of this networking activity to maintain community collaboration and knowledge transfer in the absence of in person events and travel.
Year(s) Of Engagement Activity 2020
URL https://www.sheffield.ac.uk/materials/news/cloud-conference-brings-current-research-nation-lockdown
 
Description Webinar on UK Active Research Facilities 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A one day webinar was held on 10 June 2020, in partnership with the TRANSCEND project, to showcase UK facilities for working with high activity materials and the TRANSCEND Active Research Fund. The webinar featured presentations on the HADES, UTGARD, DCF and NNL Central Laboratory facilities. The webinar facilitated a Q&A session with facility operators to assist the user community with planning future access. The event elicited interest from both existing and future users of the facilities for future access.
Year(s) Of Engagement Activity 2020