Select committee: Public Accounts Committee
Conclusion 18
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)
A notable exception to this positive trend is the ‘Replacement Analytical Project’ (RAP) – which Sellafield Ltd now believes should be abandoned.44 This project would have refurbished a laboratory on the site so Sellafield Ltd would be able to continue analysing samples of waste – which is essential to operate the site safely. It would also deliver new capabilities that will be required by another facility, the ‘Sellafield Product and Residue Store Retreatment Plant’ (SRP). Sellafield Ltd will use SRP to repackage plutonium, so it can be stored more safely.45 When the Outline Business Case was approved in 2020, Sellafield Ltd believed that RAP was very likely to cost less than £800 million, with RAP ready to support SRP by October 2027 (it expected to achieve these outcomes in 80% of the scenarios it modelled).46 By late 2023, the estimated cost had risen to £1,500–£1,800 million, while RAP would be unable to support SRP until November 2033 at the earliest (delaying its opening by at least five years).47 The NDA told us that there were several causes of this: an inadequate understanding of what Sellafield and other customers needed from RAP, over–optimism about how much it would cost, too little consideration of the condition of Sellafield’s buildings, as well as poor project management.48
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".