DAWNMANTLE - Decontamination and waste minimisation strategies for and using advanced molten salt nuclear technologies
Lead Research Organisation:
University of Manchester
Department Name: Chem Eng and Analytical Science
Abstract
Molten salt reactors and pyroprocessing technologies are likely to be key components in future nuclear fuel cycles. The attraction of these technologies can be argued is predominantly based upon the inherent safety imparted by the use of molten salt media (e.g. reduced criticality risk allowing small plant footprints; reduced likelihood of volatile radioactive species formation compared to oxide fuel reactors; plant operation at atmospheric pressures; negligible radiation degradation of molten salt media). These technologies also have the potential to be applied to current and near future decommissioning programmes such as decontaminating materials and minimizing waste volumes requiring managed disposal. Contaminated metals make up a significant proportion of the waste inventory as components (such as pipework, vessels and structural beams etc.) become contaminated during nuclear operations. In 2016, the Nuclear Decommissioning Authority reported that there is approximately 32,000 tonnes of contaminated intermediate level waste (ILW) stainless steel in the UK alone. At a current predicted rate of ~£70,000/m3 to dispose of ILW, this volume of waste adds up to a considerable cost liability.
This project aims to assess materials requirements that will allow the deployment of advanced molten salt technologies in current decommissioning programmes and across various operations in future nuclear fuel cycles, and determine whether these technologies can provide benefit the nuclear energy sector. This will be achieved by a cradle-to-grave approach by assessing the nature of all materials that come in contact with radioactive material with these approaches and attempting to provide safe and effective waste management options for all waste streams.
This project aims to assess materials requirements that will allow the deployment of advanced molten salt technologies in current decommissioning programmes and across various operations in future nuclear fuel cycles, and determine whether these technologies can provide benefit the nuclear energy sector. This will be achieved by a cradle-to-grave approach by assessing the nature of all materials that come in contact with radioactive material with these approaches and attempting to provide safe and effective waste management options for all waste streams.
Planned Impact
The key impacts from this proposed research are as follows:
- Development of molten salt technologies for decontaminating problematic steel materials from nuclear processes for reclassification to lower waste categories as part of an integrated waste management strategy.
- Materials performance assessments linked with decommissioning requirements providing comprehensive selection criteria to determine material type/s for structural containment of molten salt technologies in nuclear processes.
- Contribute to databases of spectroscopic and electrochemical information of various species (e.g. radioelements, corrosion products) in molten salt media that can be used to assess the chemical composition within these extreme environments - for immediate use by the academic community for the verification of molten salt studies, but can be used in future processes to determine salt compositions from on-line process monitoring data.
- Journal and conference publications will be submitted from this work with each output mainly focussing on the sharing of fundamental data and understanding typically related to an individual operation.
- Development of molten salt technologies for decontaminating problematic steel materials from nuclear processes for reclassification to lower waste categories as part of an integrated waste management strategy.
- Materials performance assessments linked with decommissioning requirements providing comprehensive selection criteria to determine material type/s for structural containment of molten salt technologies in nuclear processes.
- Contribute to databases of spectroscopic and electrochemical information of various species (e.g. radioelements, corrosion products) in molten salt media that can be used to assess the chemical composition within these extreme environments - for immediate use by the academic community for the verification of molten salt studies, but can be used in future processes to determine salt compositions from on-line process monitoring data.
- Journal and conference publications will be submitted from this work with each output mainly focussing on the sharing of fundamental data and understanding typically related to an individual operation.
Organisations
- University of Manchester (Lead Research Organisation)
- Nuclear Decommissioning Authority NDA (Collaboration)
- UK ATOMIC ENERGY AUTHORITY (Collaboration)
- Washington State University (Collaboration)
- Penn State University (Collaboration)
- Ulsan National Institute of Science and Technology (Collaboration)
- Seoul National University (Collaboration)
Publications
Grebennikova T
(2021)
Electrochemical decontamination of irradiated nuclear graphite from corrosion and fission products using molten salt
in Energy & Environmental Science
Mirza M
(2023)
Electrochemical recovery of lithium-ion battery materials from molten salts by microstructural characterization using X-ray imaging
in Cell Reports Physical Science
Mirza M
(2024)
Following the electrochemical recovery of lithium-ion battery materials from molten salts using operando X-ray imaging
in Materials Today
Robshaw T
(2023)
Radioiodine abatement - Development of radioiodine targeting strategies in the light of zero emission
in Progress in Nuclear Energy
Robshaw TJ
(2022)
Functionality screening to help design effective materials for radioiodine abatement.
in Frontiers in chemistry
Scrimshire A
(2024)
Benchtop Zone Refinement of Simulated Future Spent Nuclear Fuel Pyroprocessing Waste.
in Materials (Basel, Switzerland)
| Description | Implantation of He ions onto various types and grades of steel using the state of the art facilities at Dalton Cumbrian Facility has been performed to mimic embrittlement upon exposure to radiation fields. The corrosion of behaviour of these materials upon exposure to high temperature molten salts is currently taking place. Methods to test and analyse for the performance of ion exchange material for salt clean-up processes are being developed and tested. Work has explored the effects of ex-site gamma irradiation on salts and materials in the corrosion and contamination of materials. Data is still being processed and is currently being drafted for paper outputs. |
| Exploitation Route | Possible development of standard approaches for the testing of materials that are exposed to irradiation fields and high temperature molten salts. Such approaches may be of benefit to nuclear regulators in delivering evidence on the long term operational performance and safety of emerging molten salt technologies in the nuclear sector. Indications are that the assumption that salts are radiation resistant may not necessarily be correct and the data is currently being interrogated to determine if a robust conclusion can be made based on the obtained or if further studies may be required. |
| Sectors | Energy |
| Description | Combined with establishing the MSNTL facility, Dawnmantle has showcased the molten salt capabilities at the University of Manchester and our UK partners particularly integrating with the radiation sources available at the Dalton Cumbrian Facility. This generated significant industrial interest in potential use and access across the molten salt technology sector with molten salt reactor (MSR) vendors, energy storage and fusion. The Manchester hub of the MSNTL facility has been recently set up within newly refurbished Nuclear Engineering, Science and Technology (NEST) Facility with investment from the University of Manchester of £1.3M which will has the infrastructure to support the preparation and handling of fluoride salts. Numerous MSR and energy storage vendor companies, and companies with interests in pyroprocessing have established non-disclosure agreements to allow further discussions to explore research possibilities. The emergence of fusion interests in molten salt technologies has led to submissions to expand the capabilities for the MSNTL in particular the ability to safely handle and study FLiBe salt with tritium where beryllium is challenging to handle due to its toxicity, where a EPSRC Strategic Equipment Grant has recently been awarded. The Dawnmantle links with our Korean partners in Seoul National University and Ulsan National Institute of Science and Technology has led to submissions to support student exchanges of Korean students to use our facilities for training and studying molten salts with radioactive materials and sources. Of particular interest is the interactions between molten salts and graphite which has relevance across MSR designs and a novel graphite treatment approach has led to further developments in legacy graphite treatment and has potential to offer a sustainable for the management of graphite in next generation High Temperature Gas-Cooled Reactors (HTGRs). |
| First Year Of Impact | 2022 |
| Sector | Energy |
| Impact Types | Cultural Economic |
| Description | Molten Salts Technology Platform |
| Geographic Reach | National |
| Policy Influence Type | Participation in a guidance/advisory committee |
| URL | https://www.nnl.co.uk/innovation-science-and-technology/showreel/collaborations/molten-salt-technolo... |
| Description | A molten salt community framework for predictive modelling of critical characteristics |
| Amount | £581,674 (GBP) |
| Funding ID | EP/X011607/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 06/2023 |
| End | 06/2026 |
| Description | A molten salt community framework for predictive modelling of critical characteristics |
| Amount | £591,182 (GBP) |
| Funding ID | EP/X011607/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 06/2023 |
| End | 06/2026 |
| Description | Advanced Fuel Cycle Programme - Pyroprocessing |
| Amount | £774,982 (GBP) |
| Organisation | National Nuclear Laboratory |
| Sector | Public |
| Country | United Kingdom |
| Start | 09/2020 |
| End | 06/2021 |
| Description | Decontamination of carbonaceous nuclear waste streams for segregation and possible re-use |
| Amount | £120,000 (GBP) |
| Funding ID | 2747184 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 08/2022 |
| End | 09/2026 |
| Description | Measurement of melting point and density of fluoride salt mixtures |
| Amount | £86,287 (GBP) |
| Funding ID | 2055546 |
| Organisation | UK Atomic Energy Authority |
| Sector | Public |
| Country | United Kingdom |
| Start | 11/2021 |
| End | 05/2022 |
| Description | Radiochemical Facilities for the Molten Salts in Nuclear Technologies Laboratory |
| Amount | £2,330,000 (GBP) |
| Funding ID | EP/T011386/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 11/2019 |
| End | 03/2023 |
| Description | Tritium removal from molten salt media in nuclear fusion and fission processes |
| Amount | £120,000 (GBP) |
| Funding ID | 2786566 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 08/2022 |
| End | 09/2026 |
| Title | Irradiation rigs for materials testing in contact with molten salts. |
| Description | Rigs for testing the materials performance of candidate containment steel and alloys when exposed to radiation fields while in contact with molten salts have been designed. The rigs will be deployed for use with the particle accelerator (alpha particle bombardment predominantly) and the Co-60 gamma irradiator at the Dalton Cumbrian Facility. The rigs are designed to accommodate various salt types including fluorides, and allow ready sampling of salt for content analysis. The rigs have been designed and are currently being constructed. It will be made available for use after commissioning and testing. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2022 |
| Provided To Others? | No |
| Impact | Not yet. |
| Title | Rig for testing of of solid adsorbents/ion exchange material for treatment of high temperature molten salts under dynamic flow. |
| Description | This rig allows for the ready testing of solid adsorbent and ion exchange materials in the clean up of molten salts from radioactive contaminants (e.g caesium and strontium) found in the pyroprocessing of spent nuclear reactors and in the fuel of certain molten salt reactor designs. The rig is column set up that test the loading of various contaminant species onto the treatment material under dynamic flow. The rig is designed to accommodate various salt types including fluorides, and allow ready sampling of salt for content analysis. The rig has been designed and is currently being constructed. It will be made available for use after commissioning and testing. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2022 |
| Provided To Others? | No |
| Impact | None yet. |
| Description | NDA Bursary |
| Organisation | Nuclear Decommissioning Authority NDA |
| Country | United Kingdom |
| Sector | Public |
| PI Contribution | Student PhD project as part of the GREEN CDT looking advancing processes using molten salts to decontaminate irradiated nuclear graphite. Student training in the handling of molten salts has been performed |
| Collaborator Contribution | Student supervision guidance and support from NDA, NNL and Magnox. |
| Impact | The research for this project has only recently commenced. |
| Start Year | 2022 |
| Description | PSU - molten salts |
| Organisation | Penn State University |
| Department | Penn State Abington |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | Part of the UK-US recently established relationships from the Nuclear Energy Universities Programme jointly supported by EPSRC in exploring high temperature molten salt behaviour to support developments in the pyroprocessing of spent nuclear fuel and molten salt reactors. Our contribution in this relationship is to provide experimental support to the programme especially where the MSNTL can provide capabilities for the study of fluoride melts. |
| Collaborator Contribution | Penn State University will predominantly provide contributions in computational modelling that will develop predictive capability for molten salt behaviour. |
| Impact | Collaboration is multidisciplinary across chemistry and chemical engineering, and across experimental and computational activities. The collaboration has only recently commenced within a NEUP project so there are no outputs or outcomes at this stage. |
| Start Year | 2023 |
| Description | Seoul National University-DAWNMANTLE |
| Organisation | Seoul National University |
| Country | Korea, Republic of |
| Sector | Academic/University |
| PI Contribution | Studies on the contamination processes of stainless steel in molten salt process operations. Particle irradiation of stainless steel materials to mimic likely the likely radiation exposure of such materials in various nuclear operations. Preparation of materials to be used to decontamination testing. All as part of the Dawnmantle consortium supported by EPSRC (UK) and NRF (Korea) through the UK-ROK Civil Nuclear partnership. Note: this partnership originally commenced with Korea Advanced Institute of Science and Technology (KAIST) but has moved to Seoul National University following the move of Prof. Sungyeol Choi to this institute. |
| Collaborator Contribution | Studies on the development of Laser Induced Breakdown Spectroscopy to monitor molten salt compositions. Effluent treatment of possible associated waste streams from molten salt operations. All as part of the Dawnmantle consortium supported by EPSRC (UK) and NRF (Korea) through the UK-ROK Civil Nuclear partnership. |
| Impact | J. T. M. Amphlett, S. Choi, S. A. Parry, E. M. Moon, C. A. Sharrad and M. D. Ogden, Insights on uranium uptake mechanisms by ion exchange resins with chelating functionalities: Chelation vs. anion exchange, Chem. Eng. J (2020) 392, 123712. DOI: 10.1016/j.cej.2019.123712 Multidisciplinary: Chemistry, Materials Science, Chemical Engineering, Analytical Science |
| Start Year | 2019 |
| Description | UKAEA-MSNTL |
| Organisation | UK Atomic Energy Authority |
| Country | United Kingdom |
| Sector | Public |
| PI Contribution | Preparation of a series of fluoride salts of potential interest as breeder and/or coolant media for fusion reactors, and measuring their densities in the molten state and melting points. |
| Collaborator Contribution | Information regarding the motivations for salt selections for fusion, and contributions to drafting a paper output from this work which is still on going. |
| Impact | Journal paper being drafted using data obtained in this work. Construction of a density measuring device for molten salts which can be made available of other users. |
| Start Year | 2021 |
| Description | UKAEA-MSNTL-Tritium |
| Organisation | UK Atomic Energy Authority |
| Country | United Kingdom |
| Sector | Public |
| PI Contribution | Hosting of a PhD student project exploring the behaviour and extraction of tritium from molten salt media. Training of the student to handle and study molten salts. Project will utilise MSNTL facilities. |
| Collaborator Contribution | Student supervision, guidance and support including visiting of facilities, joint meetings, and equipment and sample access. |
| Impact | Student project is part of the GREEN CDT and the research has only recently commenced. |
| Start Year | 2022 |
| Description | Ulsan - Dawnmantle |
| Organisation | Ulsan National Institute of Science and Technology |
| Country | Korea, Republic of |
| Sector | Academic/University |
| PI Contribution | Studies on the contamination processes of stainless steel in molten salt process operations. Particle irradiation of stainless steel materials to mimic likely the likely radiation exposure of such materials in various nuclear operations. Preparation of materials to be used to decontamination testing. |
| Collaborator Contribution | Preparation of steel materials to mimic exposure in reactor operations. |
| Impact | Multidisciplinary - Chemistry, Materials, Chemical Engineering |
| Start Year | 2019 |
| Description | WSU - molten salts |
| Organisation | Washington State University |
| Department | Washington State University Spokane |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | Part of the UK-US recently established relationships from the Nuclear Energy Universities Programme jointly supported by EPSRC in exploring high temperature molten salt behaviour to support developments in the pyroprocessing of spent nuclear fuel and molten salt reactors. Our contribution in this relationship is to provide experimental support to the programme especially where the MSNTL can provide capabilities for the study of fluoride melts. |
| Collaborator Contribution | WSU will predominantly offer computational support in developing capabilities for predicting molten salt behaviour and performance. |
| Impact | This collaboration is multidisciplinary across chemistry and chemical engineering, while also covering experimental and computational activities. This collaboration has only recently commenced with a NEUP project so there are no outputs or outcomes at this stage. |
| Start Year | 2023 |
| Title | GRAPHITE DECONTAMINATION |
| Description | The present invention relates to methods of decontaminating irradiated nuclear graphite. The method comprises immersing the irradiated nuclear graphite in a molten salt electrolyte, and subjecting the irradiated nuclear graphite to an electrochemical treatment. |
| IP Reference | WO2021250413 |
| Protection | Patent granted |
| Year Protection Granted | 2021 |
| Licensed | No |
| Impact | - |
| Description | EAFORM 2022 - Jeju Island |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Invited talk including an opening address by Clint Sharrad at EAFORM 2022 (The 7th East Asia Forum on Radwaste Management) held at Jeju Island, South Korea. Numerous requests and discussions were had from various people across mulitple nations on possible collaborative opportunities. |
| Year(s) Of Engagement Activity | 2022 |
| Description | International Molten Salt workshop - Seoul National University |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Invited talks delivered by Clint Sharrad and Tatiana Grebennikova from the Dawnmantle consortium and MSNTL at the International Workshop of Molten Salts Chemistry and Technologies for Nuclear Applications held at Seoul National University. The workshop had expert speakers in the molten salts area from multiple nations across both academia and industry with an audience of ~ 50 people mainly consisting of postgraduate researchers and academics across South Korea. |
| Year(s) Of Engagement Activity | 2022 |