SELLAFIELD PRODUCT AND RESIDUE STORE RETREATMENT PLANT PROJECT

Infrastructure and Construction

Record date: 31 March 2026

Whole-life cost: £1.4bn
Published schedule: 01/03/2012 – 24/06/2031
NISTA delivery confidence: Not disclosed
Senior responsible owner: Gavin Askew

What the project is for

The Sellafield Product & Residue Store Retreatment Plant (SRP) project is a key element of the Sellafield Ltd ’Special Nuclear Materials Future State Programme (SNMFSP)’. The SRP is a complex major project required to provide the capability to receive special nuclear material in existing packages, from existing stores on the Sellafield site, and process the material into a form and package suitable for safe and secure long-term interim storage.

Departmental delivery commentary

Compared to financial year 24/25 Q4, the NISTA/SRO Delivery Confidence Assessment (DCA) rating at 25/26 Q4 decreased to Amber. This is primarily due to the following factors: - Impact relating to the legislative changes of Passive Fire Protection standards and the implementation of the changes to the Building Safety Act (2022) following the Grenfell Tower Inquiry. The legislative changes will require a significant amount of engineering design rework and additional installation work in the new facility; the key impact is expected to be on the schedule to achieve readiness of the facility for Glove box installation. - The project has also been impacted by extraordinary inflation and Industrial Action. This will result in a request to DESNZ PIC for P80 cost and schedule contingency sanction relief when appropriate. This is essential to restore contingency levels necessary for project completion.

Schedule

Compared to financial year 24/25-Q4, the project's end-date at 25/26-Q4 increased from 01/04/2030 to 24/06/2031. This 15 month movement is reflective of the impact of legislative changes to Passive Fire Protection standards.

Cost

The increase to the project's departmentally agreed Whole Life Cost at 25/26-Q4 is primarily due to: - Annual Indexation, in line with the agreed indices.

Benefits

Compared to financial year 24/25-Q4, the project's departmentally agreed Benefits at 25/26-Q4 (measured in £m) remained at 0. This is primarily due to the following factors There are no monetised benefits defined within the Sellafield Product & Residue Store Retreatment Plant (SRP) FBC. SRP will provide key capabilities which will enable the delivery of benefits to the Special Nuclear Materials (SNM) Future State Programme at Sellafield. The retreatment and repackaging capability provided will reduce the risk associated with current plutonium storage conditions at Sellafield. The UK has the largest inventory of separated civil plutonium in the world, most of which is stored at Sellafield, safe and secure management of this material is a priority. SNM has identified three long term benefits that will be fully realised once all plutonium packages have been retreated or repackaged and consolidated within modern storage facilities. - Enhanced nuclear Safety & Security. - Improved high security resilience and a reduction in the number of Category-1 facilities. - Value for money by reducing the size of the delivery organisation required for managing future plutonium stocks.