Simulated Used Nuclear Fuel Dissolution as a Function of Fuel Chemistry and Near Field Conditions

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

Abstract

This research is a joint UK and US effort to understand the long-term safety of used nuclear fuel (UNF), the primary waste arising from the generation of electricity by nuclear fission. With more than 440 commercial nuclear power stations operating worldwide, a significant cumulative inventory of UNF has been produced, on the order of 300,000 metric tonnes. In the UK, several new nuclear reactors are planned for construction (e.g. Hinkley Point C), and the UNF reprocessing capability at Sellafield (ThORP) is due to close in 2018. Hence, the UK inventory, currently estimated at 3,500 - 8,000 tonnes, will continue to grow. The US currently (April 2016) has 80,150 metric tonnes of UNF, with a prediction of a total of approximately 140,000 metric tons by around 2050 when all currently operating reactors reach their designated life.

The UK and the US presently have no final disposal route for UNF; fuel is currently stored in cooling ponds (UK and US) or dry storage (US only), but this is not a sustainable final solution. Both countries agree that disposal in a deep (200 m - 1000 m) geological formation is the most suitable solution, since it will isolate the UNF from the biosphere and future populations for more than 100,000 years - the period of time for which this material will be highly radioactive. In such a Geological Disposal Facility (GDF), the release of radionuclides to the environment will be controlled by the interaction of the UNF with groundwater, and with the materials that have been built as an engineered barrier around the waste, particularly the fuel cladding and the metal canister. Fundamental mechanistic understanding of how UNF interacts with groundwater under GDF conditions is of paramount importance for UK and US waste management programs, which seek to satisfy citizens and regulators regarding the reliability of long-term degradation predictions for UNF originating from a variety of fuel designs, burn-ups, reactor operations, and storage conditions.

This research project is envisioned as a collaborative and joint enterprise between leading researchers from the UK and US who, collectively, bring mutually complementary and compatible skills, capabilities, and interests required to achieve a paradigm shift in our fundamental understanding of UNF dissolution in the presence of cladding and canister materials, and local groundwater conditions. This understanding will underpin the maturation of models for UNF evolution and interaction under different repository conditions, enabling reliable prediction of degradation and adjustment of repository conditions to achieve desired long-term performance and providing confidence in predicting behaviour for up to one million years.

Planned Impact

Through the generation of much-needed fundamental science on dissolution mechanisms of UO2 and related used nuclear fuel materials, particularly in the presence of cladding materials and under different oxidising / reducing conditions, this research has the potential to impact the plans to deliver a geological disposal facility in the UK and the US. Importantly, the generation of improved understanding in the long-term behaviour of used nuclear fuel, and its interactions with the other materials in the engineered barrier, could influence public confidence in the disposal concepts under consideration. This is vital, particularly for the success of the UK voluntary site selection process that is currently underway. Once a site for geological disposal has been selected, there will be a significant reduction in the hazard arising from nuclear waste currently stored around the UK in above-ground facilities, and indications from Government are that future investment in new nuclear power will be made once a final disposal solution is in place. This will reduce the threat from the 'energy trilemma' and have far-reaching impacts to the economy, the environment and society.

The impacts will be realised through the primary beneficiaries, who include academic and non-academic researchers in the field of used nuclear fuel dissolution, and international waste management organisations responsible for implementing geological disposal solutions for used nuclear fuel, and also the early career researchers involved in the proposed project. The impacts to these groups include:

- New scientific understanding and data to support development of a post-closure safety case for geological disposal;
- Publications in peer-reviewed journals, conference proceedings and lay-person articles (e.g. The Conversation);
- Potential reduction of the estimated £18Bn cost of radioactive waste disposal in the UK, through more appropriate disposal facility design led by an improved understanding and confidence in spent fuel durability;
- Improved public confidence in UK radioactive waste disposal strategy, through provision of underpinning scientific understanding and data;
- Strengthened UK-US collaborative efforts in nuclear waste management and disposal.

The Pathways to Impact will focus on developing a forum for the exchange of knowledge with the primary beneficiaries; this will take the form of a final workshop in Y3 of the proposed project, with presentations on the research and round-table discussions about how this, and future research, can be incorporated into plans for US and UK geological disposal facility plans. The knowledge exchange forum will also extend to publicising the progress of the research to the wider public, and presenting key findings to the primary beneficaries, on the PI's website (funded through her EPSRC ECR Fellowship), the "Nuclear Waste Repository".
 
Description Using simulant materials (uranium dioxide) we are gaining insight to the type of damage caused to UO2 fuel when it is subject to alpha radiation. This type of radiation will dominate when the fuel is disposed of in a geological disposal facility. It is important to understand how the microstructure and chemistry of the fuel will be influenced since these also influence the long-term stability. They key finding from this work is that grain boundaries in the UO2 are capable of repairing some of the damage caused by radiation. However, we also find that doping the UO2 with fission products, as the case in real spent UO2 fuel, reduces this repair mechanism.
Exploitation Route It is anticipated that these findings will be of interest to the UK and US spent nuclear fuel storage and disposal implementers.
Sectors Energy,Environment

 
Description International Atomic Energy Agency Predisposal Network Steering Committee
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a advisory committee
 
Description Member HM Goverment Committee on Radioactive Waste Management
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
 
Description Disposal MOX fabrication and characterisation
Amount £250,000 (GBP)
Organisation Nuclear Decommissioning Authority NDA 
Sector Public
Country United Kingdom
Start 11/2020 
End 09/2021
 
Description Dissolution of neutron poisons from zirconolite - NNL
Amount £69,657 (GBP)
Organisation Nuclear Decommissioning Authority NDA 
Sector Public
Country United Kingdom
Start 10/2020 
End 03/2021
 
Description Long-term durability of plutonium-containing glass ceramics
Amount £305,946 (GBP)
Organisation Nuclear Decommissioning Authority NDA 
Department Radioactive Waste Management
Sector Public
Country United Kingdom
Start 10/2019 
End 03/2021
 
Description Plutonium wasteform dissolution - RWM
Amount £988,914 (GBP)
Funding ID RWM313 
Organisation Nuclear Decommissioning Authority NDA 
Department Radioactive Waste Management
Sector Public
Country United Kingdom
Start 02/2021 
End 02/2026
 
Description The NEUP Project 
Organisation Washington State University
Country United States 
Sector Academic/University 
PI Contribution Characterization and irradiation of surrogate nuclear fuels
Collaborator Contribution Positron Annihilation Spectroscopy (PAS) and TGA measurements of the irradiated pellets
Impact Collaboration has allowed us to correlate our experimental data with new PAS results
Start Year 2018
 
Description UK-US spent nuclear fuel research 
Organisation Washington State University
Department Washington State University Spokane
Country United States 
Sector Academic/University 
PI Contribution Professor John McCloy from Washington State University and I are collaborating on a US-UK NEUP-EPSRC grant, to understand the behaviour of spent nuclear fuel during disposal and storage. We have provided materials and shared expertise and networks within the European spent nuclear fuel research community.
Collaborator Contribution Partners have shared expertise and equipment.
Impact Publications to date include: 1. Brehault A., Patil D., Kamat H., Youngman R. E., Thirion L. M., Mauro J. C., Corkhill C. L., McCloy J. S. and Goel, A. Compositional dependence of solubility / retention of molybdenum oxides in aluminoborosilicate-based model nuclear waste glasses. Journal of Physical Chemistry B, 122, 1714 - 1729 (2018) 2. Chong S., Peterson J. A., Riley B. J., Tabada D., Wall D., Corkhill C. L. and McCloy J. S. Glass-bonded iodosodalite waste form for immobilisation of 129I. Journal of Nuclear Materials, 504, 109 - 121 (2018)
Start Year 2017
 
Description A long-term solution: film for Radioactive Waste Management Limited 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Was the presenter of a short film describing the UK Government's policy on nuclear waste geological disposal. Participating in the filming has enhanced relationship with key policy makers.
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=uoPSaWV-tQU
 
Description BBC 5 Live / BBC Cambridge / The Naked Scientists podcast 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interviewed for BBC Radio Cambridge and the Naked Scientists podcast on radioactive waste disposal.
Year(s) Of Engagement Activity 2020
URL https://twitter.com/NakedScientists/status/1246857392463269888
 
Description BBC Breakfast: Chernobyl 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Appeared on BBC Breakfast show to discuss the decommissioning efforts at Chernobyl and Fukushima and our research that supports them.
Year(s) Of Engagement Activity 2019
 
Description BBC R4 Today programme: feature on geological disposal 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interviewed for BBC R4 Today Programme feature on geological disposal of nuclear waste.
Year(s) Of Engagement Activity 2019
 
Description BBC R4 World Tonight interview: radioactivity release in Russia 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interviewed on BBC R4 The World Tonight to discuss the release of radioactivity in Russia after a failed missile test. This sparked further media interest in the topic.
Year(s) Of Engagement Activity 2019
 
Description BBC Sheffield interview: Chernobyl 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Interviewed by Kat Cowan on the BBC Radio Sheffield breakfast show, to discuss the Chernobyl accident and our research that is helping to support the decomissioning efforts at both Chernobyl and Fukushima.
Year(s) Of Engagement Activity 2019
 
Description BBC World Service - nuclear fuel removal 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interviewed by Ritulah Shah on BBC World Service News Hour programme, to discuss the removal of nuclear fuel from the Fukushima Daiichi nuclear power plant.
Year(s) Of Engagement Activity 2019
URL https://www.bbc.co.uk/news/world-asia-47933031
 
Description BBC World Service Science in Action interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interviewed on the BBC World Service Science in Action programme about the radioactivity release associated with the Russian missile test failure, and our research in nuclear forensics.
Year(s) Of Engagement Activity 2019
URL https://www.bbc.co.uk/programmes/w3csym26
 
Description BBC5Live Interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interviewed on the Sarah Bretty show on BBC5Live to discuss the science behind the decommissioning of the Fukushima and Chernobyl nuclear reactors.
Year(s) Of Engagement Activity 2019
 
Description CNN interview - Fukushima contaminated water release 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Gave CNN interview on the topic of radioactive water stored at the Fukushima site.
Year(s) Of Engagement Activity 2020
URL https://edition.cnn.com/2020/10/24/asia/japan-fukushima-waste-ocean-intl-scli/index.html
 
Description Chernobyl Live Tweet 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I live tweeted 6 episodes of Sky Atlantic's "Chernobyl" mini-series, giving the scientific facts and truths behind the show, including how our EPSRC-funded research is being used to help clean up the Chernobyl and Fukushima nuclear power plants. My tweets received millions of impressions and hundreds of thousands of likes and solicited a great amount of media interest in our research.
Year(s) Of Engagement Activity 2019
URL https://twitter.com/clairecorkhill
 
Description CoRWM presentation at NDA Integrated Waste Management Programme Stakeholder Workshop 
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 Gave a talk on behalf of the Committee on Radioactive Waste Management at the Nuclear Decommissioning Authority's Integrated Waste Management Programme Stakeholder Workshop.
Year(s) Of Engagement Activity 2020
URL https://www.marickpartners.co.uk/iwmp/
 
Description Engineering Matters Podcast 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interviewed for Engineering Matters podcast on radioactive waste decommissioning and disposal
Year(s) Of Engagement Activity 2020
URL https://engineeringmatters.reby.media/2020/03/13/50-dealing-with-nuclear-waste/
 
Description Financial Times interview 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Interviewed for Financial Times article "UK returns to grappling with toxic nuclear waste dilemma" - quoted in main article.
Year(s) Of Engagement Activity 2021
URL https://www.ft.com/content/2321bfae-839a-468f-b933-d699b6ff6864
 
Description ITV This Morning 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Appeared on the sofa with Holly and Phil on ITV's This Morning show to discuss radioactivity, Chernobyl and our research to support decommissioning at Fukushima and Chernobyl.
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=6x2PcB-XaVA
 
Description International Atomic Energy Agency Coordinated Research Project on Severely Damaged Nuclear Fuel 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited to attend as an expert contributor to the International Atomic Energy Agency Coordinated Research Project on Severely Damaged Nuclear Fuel, which met in Fukushima Prefecture to discuss latest R&D in degraded nuclear fuel materials, and to identify future research needs.
Year(s) Of Engagement Activity 2018
 
Description International Spent Nucleear Fuel Workshop 
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 My team and I organised the bi-annual International Spent Nuclear Fuel Workshop in Sheffield, in May 2018. There were 125 participants from 16 countries, including academic researchers in materials science and engineering, environmental science and social science.
Year(s) Of Engagement Activity 2018
 
Description Invited talk Scientific Basis for Nuclear Waste Management, IAEA 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Gave keynote talk at the Scientific Basis for Nuclear Waste Management conference, hosted by the International Atomic Energy Agency. Sparked debate about future research requirements in the field.
Year(s) Of Engagement Activity 2019
 
Description Invited talk at the IChemE 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Gave invited talk at IChemE webinar on the application of synchrotron x-ray techniques to understand radioactive materials.
Year(s) Of Engagement Activity 2021
URL https://www.icheme.org/membership/communities/special-interest-groups/nuclear/events/24-02-21-new-op...
 
Description MRS conference presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Gave talk on high level waste glass dissolution at Materials Research Society Symposium: Scientific Basis for Nuclear Waste Management
Year(s) Of Engagement Activity 2020
 
Description NDA Blog interview 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Interviewed for the Nuclear Decommissioning Authority blog regarding the decommissioning of Chernobyl and Fukushima, and how research being performed in support of Sellafield decommissioning is supporting this.
Year(s) Of Engagement Activity 2019
URL https://nda.blog.gov.uk/2019/06/07/chernobyl-drama-sparks-huge-interest-in-nuclear-so-lets-talk-abou...
 
Description NERC RATE programme blog 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Interviewed for NERC Radioactivity and the Environment research programme knowledge exhange blog, about our research associated with Fukushima and Chernobyl fuel debris.
Year(s) Of Engagement Activity 2019
URL http://rateknowledgeexchange.com/post/chernobyl-hbo
 
Description Nature News article: How nuclear scientists are decoding Russia's mystery explosion 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interviewed for Nature News article "How nuclear scientists are decoding Russia's mystery explosion". Article solicited further media interest in our research.
Year(s) Of Engagement Activity 2019
URL https://www.nature.com/articles/d41586-019-02574-9
 
Description Nuclear Waste Dig Deep or Aim High? Talk at Sheffield Round Table 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Third sector organisations
Results and Impact Gave talk on the geological disposal of nuclear waste at the Sheffield Round Table monthly seminar series. Lively debate about nuclear energy ensued, with audience members reporting change in opinion (for the positive) regarding nuclear waste disposal.
Year(s) Of Engagement Activity 2019
 
Description Presentation to Allerdale Borough Council on behalf of CoRWM 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other audiences
Results and Impact Delivered presentation to Allerdale Borough Council (part of the Allerdale Geological Disposal Facility Working Group) about CoRWM and support available from CoRWM during the GDF siting process.
Year(s) Of Engagement Activity 2021
 
Description Sky News article: Chernobyl became a huge hit 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interviewed for Sky News opinion piece: "How Chernobyl quietly became a huge TV hit: A nuclear scientist, a TV writer and a journalist who grew up in the Soviet Union speak to Sky News about Chernobyl's success."
Year(s) Of Engagement Activity 2019
URL https://news.sky.com/story/how-chernobyl-quietly-topped-the-tv-charts-11732879
 
Description Spent Nuclear Fuel workshop, Ghent 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Gave presentation at the bi-annual spent nuclear fuel workshop -- my team also gave presentations. Lively debate ensued with academic peers.
Year(s) Of Engagement Activity 2019
 
Description Talk at Tapton School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Gave talk on "The mineralogy of a nuclear meltdown" at the Tapton School science club seminar series, sparking questions about materials science and how to go about studying it at University.
Year(s) Of Engagement Activity 2019
 
Description The Conversation: "Nuclear Powered" missile accident in Russia - what really happened? 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Authored article for The Conversation on the radioactivity released from a failed Russian missile test. There were 51,00 readers of the article and it prompted discussion with 43 comments made.
Year(s) Of Engagement Activity 2019
URL https://theconversation.com/nuclear-powered-missile-accident-in-russia-what-really-happened-121966
 
Description The Conversation: Nuclear waste is piling up: Governments need to stop dithering and take action 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Authored article in The Conversation, titled "Nuclear waste is piling up: Governments need to stop dithering and take action". Article was read by 5000 people and 33 comments were made in the discussion section. The article was also published in other news outlets e.g. phys.org.
Year(s) Of Engagement Activity 2019
URL https://theconversation.com/nuclear-waste-is-piling-up-governments-need-to-stop-dithering-and-take-a...
 
Description Trade Union Congress panel on Delivering Geological Disposal 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Third sector organisations
Results and Impact Participated in an expert panel on "Radioactive Waste: Delivering Geological Disposal", at the Trade Union Congress Fringe event, organised but TUSNE (Trade Union for Safe Nuclear Energy). Discussed aspects of environmental impact, benefits, policy, location and safety of geological disposal of nuclear waste. Audience members reported a change in opinion after the event.
Year(s) Of Engagement Activity 2019
URL https://nda.blog.gov.uk/2019/09/26/radioactive-waste-management-takes-gdf-to-the-tuc-congress-2019/
 
Description Yorkshire Post 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Interviewed by the Yorkshire Post about my research supporting the clean up of nuclear waste and its eventual disposal in a geological disposal facility. Also discussed our work on nuclear fuel debris to support decommissioning operations at Chernobyl and Fukushima.
Year(s) Of Engagement Activity 2019
URL https://www.yorkshirepost.co.uk/news/environment/meet-sheffield-scientist-clearing-worlds-nuclear-wa...