Question to the Department for Energy Security & Net Zero:

To ask His Majesty's Government how a decision about the plutonium stockpile at Sellafield was made; and what work has been done to establish the potential of technology that could produce mixed oxide fuel from plutonium.

The Government decided to immobilise the UK’s civil separated plutonium inventory based on analysis of strategic, economic, technical and safety and security considerations. This included both immobilisation and re-use in mixed oxide (MOX) fuel options. No UK reactor projects use plutonium-based fuel and the UK’s MOX fuel plant closed in 2011.

Immobilisation will deliver the Government’s objective to put this material into a safer and more stable form for long-term storage and ensure it is suitable for disposal in a Geological Disposal Facility (GDF).