Dr Claire Corkhill

The UK has a significant inventory of nuclear waste (650,000 cubic metres - enough to fill Wembley Stadium), that will be radioactive for over 100,000 years. For this reason, it is necessary to dispose of the waste safely in a final disposal facility, several hundreds of meters below the ground, which is carefully designed to reduce the likelihood of radioactive substances escaping to the environment. It uses a multi-barrier concept, where several layers of containment made from a number of different materials prevent groundwater reaching the waste, preventing the leaching of radioactive substances into the host rock. This concept is called the Engineered Barrier.

Claire’s research focuses on understanding and improving the safety functions of this Engineered Barrier. She is interested in understanding how quickly the waste is likely to dissolve if it comes into contact with groundwater, and also how the backfill material helps to prevent the release and transport of radioactive substances to the host rock. Understanding these processes is critical to developing a safe disposal facility, and will also help the design of new, improved materials for the Engineered Barrier.

Claire is currently working in three major areas, which are as follows:

Grain boundaries:
Effect of defect chemistry and microstructure on the corrosion of UO2 fuel and Pu-containing materials. Claire’s research team are exploring the role of ceramic and glass/ceramic microstructures on the dissolution kinetics and mechanisms of UO2 and Pu-containing materials, through the study of surface chemistry and the application of in-situ dissolution imaging techniques. One recent focus has been to understand the secondary phase formation on fuel debris from the Fukushima Daiichi nuclear power plant, in support of fuel retrieval operations.

Glass:
State-of-the-art determination of nuclear waste glass durability in sub-surface environments. The role of different geochemical conditions on the dissolution kinetics of a range of simulant nuclear waste glasses are investigated, in particular, hyper-alkaline conditions.

Cement radionuclide interactions:
High-resolution spectroscopic determination of radionuclide – cement interactions. Through the application of sophisticated spatially-resolved synchrotron X-ray techniques, solid-state NMR and thermodynamic modelling, Claire’s team is developing kinetic models of radionuclide-cement interactions in geological disposal environments. Claire is leading the world’s first long-duration x-ray synchrotron experiment in collaboration with Diamond Light Source, to understand the long-term behaviour of cement over thousands of years.

Current projects

• Critical Analysis of Spent Fuel Structure in Radionuclide Release (EPSRC ECR Fellowship)
• Transcend: Transformative Science and Engineering for Decommissioning Research (EPSRC/ Radioactive Waste Management Limited)
• ATLANTIC: Accident ToLerANT fuels In reCylcing (EPSRC)
• Simulated Used Nuclear Fuel Dissolution as a Function of Fuel Chemistry and Near Field Conditions (EPSRC / US Department of Energy)
• DisCo: Modern Spent Fuel Dissolution and Chemistry in Failed Container Conditions (H2020)
• JUNO: A Network for Japan – UK Nuclear Opportunities (EPSRC)
• Project GLAD: Glass Leaching Assessment for Durability (US Department of Energy, Office of River Protection)
• CEBAMA: Cement BAsed MAterials for final disposal of nuclear waste (H2020)
• Next Generation Nuclear and GREEN Centres for Doctoral Training (EPSRC)