Interactions between the co-located intermediate-level waste/low-level waste and high-level waste/spent fuel components of a geological disposal facility

Abstract

The 2008 UK government White Paper, published as part of the Managing Radioactive Waste Safety programme, identified benefits to disposing of all of the UK's higher activity wastes at the same site. That is, a single geological disposal facility (GDF) could be constructed that consists of a module for low- and intermediate-level waste, and a module for high-level waste and spent fuel.A safety case for a co-located GDF will have to consider the extent to which evolving thermo-hydro-mechanical-chemical and gas (THMCG) conditions in and around one module may affect conditions in the other module, including the extent to which barrier performance and radionuclide migration behaviour could be altered. Several research projects have been undertaken on behalf of Radioactive Waste Management Directorate aimed at understanding and evaluating the THMCG interactions that might occur during the disposal facility operational and post-closure phases.This paper describes research on THMCG interactions between disposal modules based on illustrative GDF designs for different host rock environments. Interactions were evaluated using simple analytical solutions and detailed three-dimensional models. The analyses demonstrated that interactions can be controlled by design constraints.

Geological disposal of radioactive waste: underpinning science and technology

“…The final section on general matters begins with a contribution which describes the framework for an environmental safety case for geological disposal in the UK from Mike Poole and Ray Kowe of the NDA (Poole and Kowe, 2012). There follow papers which describe: research in support of the 2011 environmental safety case for the low level waste repository by Andrew Baker (Eden Nuclear and Environment Ltd) and Richard Cummings (Low Level Waste Repository Ltd) (Baker and Cummings, 2012); interactions between the co-located intermediate-level waste/ low-level waste and high-level waste/spent fuel components of a geological disposal facility by Tim Hicks (Galson Sciences Ltd) and co-workers (Hicks et al, 2012a); performance assessment and the safety case: lessons from the European Commission PAMINA project by Daniel Galson (Galson Sciences Ltd) and Lucy Bailey (NDA) (Galson and Bailey, 2012); planning to 'remember to forget'? by Shelly Mobbs (Eden Nuclear and Environment Ltd) (Mobbs, 2012); and geological disposal programme design and prioritization in the face of uncertainty: use of structured evidence support logic techniques by Alan Paulley (Quintessa Ltd) and co-workers (Paulley et al, 2012).…”