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Written question asked by Helen Maguire (Liberal Democrat) on Tuesday, 4 November 2025, in the House of Commons. It was due for an answer on Tuesday, 11 November 2025. It was answered by Michael Shanks (Labour) on Monday, 17 November 2025 on behalf of the Department for Energy Security and Net Zero.


Plutonium

Question

To ask the Secretary of State for Energy Security and Net Zero, what quantities of unprocessed plutonium remain within discharged irradiated spent nuclear fuel at (a) nuclear reactor sites and (b) Sellafield.

Answer

Plutonium is a by-product of nuclear fission, and it is present in small quantities in spent irradiated fuel. However, the quantities would vary based on the fuel and reactor type.

The Office for Nuclear Regulation publishes annual figures on estimated amounts of plutonium contained in spent civil reactor fuel in the UK. The most recently published data can be found at the following link: 2023 annual figures for holdings of civil unirradiated plutonium | Office for Nuclear Regulation


Secondary information

Type
Written question
Reference
88154
Session
2024-26
Subjects
Nuclear reactors Sellafield Plutonium
Contains statistics
Yes
Link
View this Written question on www.parliament.uk