Select committee: Public Accounts Committee
Conclusion 11
28th Report - Decommissioning Sellafield
Published 4 Jun 2025
Addressed to HM Treasury
Public Accounts Committee Decommissioning Sellafield All items in this report Report on parliament.uk ↗ Inquiry on parliament.uk ↗
Conclusion (the committee's words)
Sellafield Ltd has shown that it is technically possible to retrieve waste from all of its oldest ponds and silos.25 The plan to make the site less hazardous assumes that it will be able to significantly accelerate the speed it works at over the next few years – and then sustain that pace until tasks are completed. This was described to us by the NDA as “being able to crawl before we can walk, and then walk before we can run”. Sellafield Ltd told us that it expects the teams removing waste from the ‘Pile Fuel Cladding Silo’ to remove at least three times as much waste in 2025–26 as they did in 2024–25 (and ideally, five times as much).26 It also expects to remove significantly more waste from the ‘Magnox Swarf Storage Silo’ from the early 2030s (potentially retrieving 24 times as much as it did in 2023–24 by the middle of that decade). Sellafield Ltd told us that its focus over the 20 Qq 42–47, 69 21 Letter from the Group Chief Executive Officer at the Nuclear Decommissioning Authority relating to the oral evidence session held on 20 March on Decommissioning Sellafield, 4 April 2025, pages 1–2 22 Q 12 23 Q 84 24 C&AG’s report, Figure 9 25 Q 20 26 Qq 14–15 11 next few years will be on developing the capability to do this (including installing additional machinery to retrieve waste and finishing building the ‘Box Encapsulation Plant’ elsewhere on the site).27
From: Public Accounts Committee, 28th Report - Decommissioning Sellafield (HC 363), 4 June 2025
Government response
Latest Treasury Minutes progress report to the Committee of Public Accounts on the Twenty-eighth Report of Session 2024-26
The government responded to the whole report on 4 June 2026 (deadline 4 August 2025).
Treasury minutes: Government response to the Committee of Public Accounts on the Twenty-eighth report from Session 2024-26
Published 18 September 2025.
Summary written by Accountability Index from the government's response. It is not the government's own words.The government says it agrees with each of the Committee's recommendations covered in this extract, with target implementation dates ranging from December 2025 to March 2027, though some are already implemented and some publication details remain to be settled.
- On oversight (recommendation 1), the government agrees and describes the recommendation as implemented. Since January 2025 the department's Principal Sponsor chairs monthly performance meetings, and a review of the revised governance structure will be initiated within 2025-26.
- On medium-term targets (recommendation 2), the government agrees, with a target date of March 2027. Work "is required to establish how and then when this information would be made public", and DESNZ will commission an independent, externally led review of the NDA Group by end-2025.
- On asset management (recommendation 4), the government agrees and says the recommendation is implemented. It states that "Solely increasing the productivity of maintenance teams misses the demands" of the site's complex asset picture.
- On long-term cost scenarios (recommendation 5), the government agrees, with a target date of December 2026. It says "It will be necessary to agree the mechanism and timing, including what is published".