DEVELOPMENT OF A RANGE OF STANDARDISED DISPOSAL CONTAINERS FOR HIGH LEVEL WASTE AND SPENT FUEL DEEP DISPOSAL IN THE UK

The Nuclear Decommissioning Authority (NDA) has established the Radioactive Waste Management Directorate (RWMD) to manage the delivery of geological disposal for higher activity radioactive wastes as required under UK Government policy. Three illustrative concepts of a geological disposal facility (GDF), corresponding to three generic geological environments - higher strength rock, lower strength sedimentary rock and evaporite rock - have been developed to demonstrate the viability of geological disposal of intermediate level waste (ILW), high level waste (HLW) and spent fuel. Advantages have been identified by the development of a new range of disposal containers for HLW, AGR and PWR Spent Fuel and the revised disposal container features include; diameter, length, handling feature at both ends, balancing of radiation dose to backfill, construction method and closure arrangement. The advantages include simplified construction and standardisation of handling and emplacement operations at a GDF, simplified procedures, reduced costs, reduction in the number of waste packages, a smaller GDF footprint and a reduction in the material of construction and backfill material. A project to develop these standardised disposal container designs was carried out in 2011- 2012. The work developed two variants of these designs to be compatible with a range of environments, with a ‘corrosion resistant’ variant to provide complete containment of the waste for over 100,000 years and a ‘corrosion allowance’ variant to provide complete containment of the waste for the duration of about 10,000 years. Three internal configurations were considered - for HLW in waste vitrified product (WVP) canisters, AGR spent fuel in slotted fuel cans and PWR spent fuel. The ‘corrosion resistant’ variant has a copper containment boundary with structural cast iron internals, and the ‘corrosion allowance’ variant is a carbon steel construction with internal basket for location of the contents. This paper presents the conceptual designs of the standardised disposal containers and describes the challenges addressed in the development, when consideration was given to manufacture, shielding and structural performance.