UK Inquiry Tracker

Decommissioning Sellafield

Public Accounts Committee Closed Inquiry

Opened: 31 Oct 2024 Closed: 21 Aug 2025 Parliament page

The Sellafield nuclear site closed in 2003, having operated since 1950. Work began to decommission the site in 2005. Highly hazardous materials are stored there from across the UK’s nuclear industry, and it holds a legacy of contaminated buildings, untreated waste and ageing facilities. The Nuclear Decommissioning Authority (NDA), the … Read more The Sellafield nuclear site closed in 2003, having operated since 1950. Work began to decommission the site in 2005. Highly hazardous materials are stored there from across the UK’s nuclear industry, and it holds a legacy of contaminated buildings, untreated waste and ageing facilities. The Nuclear Decommissioning Authority (NDA), the public body in charge of Sellafield, expects full site remediation will take until 2125. The forecast future cost of decommissioning Sellafield, after adjusting for inflation, was £136bn in March 2024 – this is 18.8% higher than it was in March 2019. The Committee last reported on Sellafield in 2018, when it found that Government needed a firmer grip on the challenges the site presents. The report recognised that significant milestones had been met in reducing risk at the high hazard facilities at Sellafield, it found that most major projects there were significantly delayed, with expected combined cost overruns at the time of £913m. Earlier that same year, the Committee scrutinised the procurement and management of the contract to clean up the Magnox nuclear reactor and research sites, finding that costly mistakes in these areas caused untold reputational damage to the NDA. The National Audit Office (NAO) found in 2024 that, despite progress having been made since 2018 on areas including hazardous waste retrieval and storage, value for money is not yet being achieved at Sellafield. The report the need to address the deteriorating condition of key assets, the lack of a comprehensive measure to assess progress in reducing risk, and large projects still being delivered later than planned and at higher cost. Based on the NAO report, the Committee will hear from senior officials at the NDA, DESNZ and Sellafield Ltd on subjects including: - Risk reduction and progress to date in managing risk; - Progress towards decommissioning with ongoing and future costs; and - Operational effectiveness and organisational culture. Please look at the requirements for written evidence submissions and note that the Committee cannot accept material as evidence that is published elsewhere. If you have evidence on these issues please submit it here by 23:59 on Thursday 6 March 2025. Show less

9 Recommendations

23 Conclusions

1 Report

1 Oral session

7 Letters

1 Event

Activity timeline 11 events

8 Jan
2026

Correspondence

Letter from the Interim Permanent Secretary at the Department for Energy Security & Net Zero relating to Decommissioning Sellafield, 12 Dec…

8 Jan
2026

Correspondence

Letter from the Group Chief Executive of the Nuclear Decommissioning Authority relating to Decommissioning Sellafield, 12 December 2025

15 Dec
2025

Correspondence

Letter from the Chief Executive Officer of Sellafield Ltd relating to recommendations of the Committee’s Twenty-eighth Report on Decommissi…

24 Nov
2025

Correspondence

Letter from the Chair to the Permanent Secretary at the Department for Energy Security and Net Zero, the Group Chief Executive Officer at t…

18 Sep
2025

Report published

Treasury minutes: Government response to the Committee of Public Accounts on the Twenty-eighth report from Session 2024-26

4 Sep
2025

Correspondence

Letter from the Chief Executive Officer at Sellafield Limited relating to the 28th Report of Session 2024-25, Decommissioning Sellafield, R…

4 Jun
2025

Report published

28th Report - Decommissioning Sellafield

24 Apr
2025

Correspondence

Letter from the Group Chief Executive Officer at the Nuclear Decommissioning Authority relating to the oral evidence session held on 20 Mar…

7 Apr
2025

Correspondence

Letter from the Group Chief Executive Officer of the Nuclear Decommissioning Authority relating to Public Accounts Committee’s visit to Sel…

20 Mar
2025

Oral evidence

Oral evidence session

20 Mar
2025

Formal meeting (oral evidence session) · The Grimond Room, Portcullis House

Committee event

Oral evidence sessions 1 session

20 Mar 2025

View on parliament.uk

Clive Maxwell · Department for Energy Security and Net Zero David Peattie · Nuclear Decommissioning Authority Euan Hutton · Sellafield Ltd Kate Bowyer · Nuclear Decommissioning Authority Lee McDonough · Department for Energy Security and Net Zero

Reports 1 report · click to expand

Title	HC No.	Published	Items	Response
28th Report - Decommissioning Sellafield	HC 363	4 Jun 2025	32	Responded

Recommendations & Conclusions

2 results

13 Conclusion Not Addressed

28th Report - Decommissioning Sell…

Major project delays and costs at Sellafield significantly escalated since 2018 due to poor planning.

When it last took evidence on Sellafield, the previous Committee was told that major project delivery was improving.32 The NDA told it that “cost forecasting is improving” while the Department said that “for the first time now, the estimates of … Read more

Government Response

The government response does not directly address the committee's finding of increased costs and delays for major projects, instead citing a 2024 NAO report that noted positive progress in more recent projects and praised the Programme and Project Partners model.

HM Treasury

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28 Conclusion

28th Report - Decommissioning Sell…

Geological Disposal Facility project experiences significant delays and slow progress.

The NDA also needs to construct a ‘Geological Disposal Facility’ (‘GDF’) to store waste permanently – including that currently at Sellafield. This project is still at a very early stage: it needs to drill boreholes before it can even start … Read more

HM Treasury

View details

Government Response AI assessment · 31 of 9 classified

Accepted 28

Acknowledged 2

Not Addressed 1

Total 9 recs + 23 conclusions

Correspondence 7 letters

8 Jan 2026 To committee Letter from the Interim Permanent Secretary at the Department for Energy Security & Net Zero relating to Decommissioning Sellafield, 12 December 2025

Parliament page

8 Jan 2026 To committee Letter from the Group Chief Executive of the Nuclear Decommissioning Authority relating to Decommissioning Sellafield, 12 December 2025

Parliament page

15 Dec 2025 To committee Letter from the Chief Executive Officer of Sellafield Ltd relating to recommendations of the Committee’s Twenty-eighth Report on Decommissioning Sellafield, 04 December 2025

Parliament page

24 Nov 2025 To committee Letter from the Chair to the Permanent Secretary at the Department for Energy Security and Net Zero, the Group Chief Executive Officer at the Nuclear Decommissioning Authority and the Chief Executive Officer at Sellafield Ltd relating to Treasury Minute response – Decommissioning Sellafield, 14 November 2025

Parliament page

4 Sep 2025 To committee Letter from the Chief Executive Officer at Sellafield Limited relating to the 28th Report of Session 2024-25, Decommissioning Sellafield, Recommendation 4, 13 August 2025

Parliament page

24 Apr 2025 To committee 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, 04 April 2025

Parliament page

7 Apr 2025 To committee Letter from the Group Chief Executive Officer of the Nuclear Decommissioning Authority relating to Public Accounts Committee’s visit to Sellafield, March 17

Parliament page