Plutonium utilization options in future UK PWRs using MOX and Inert Matrix Fuels

In April 2005, the UK Nuclear Decommissioning Authority (NDA) took ownership of most of the civil nuclear liabilities and assets in the UK These include the separated civil plutonium stocks, which are expected to rise to ∼ 100 tonnes by the end of reprocessing in the UK Nexia Solutions is currently carrying out research under contract with the NDA to evaluate the technical feasibility of a number of disposition options, including reactor reuse and immobilization of plutonium as a waste for disposal. In the case of the re-use options and following a preliminary down selection process, two different reactor types are initially being considered; Sizewell 'B', a Westinghouse four loop design and the only existing Pressurized Water Reactor (PWR) in the UK and the Westinghouse AP1000 PWR, one of the reactor systems that is a candidate for new nuclear build in the UK Both Mixed Oxide (MOX) and Inert Matrix Fuel (IMF) are considered as potential future fuels. The paper presents not only the details of the technical evaluations completed, but also highlights the key findings, what has been learnt during the evaluations, what is still to be learnt and the recommendations of the way forward regarding both the technical work and the strategic options for the UK.