Office for Nuclear Regulation

Sellafield – Inspection ID: 52383

Executive summary

Date(s) of inspection:

  • April 2023

Aim of inspection

Gain assurance that Spent Fuel Services (SFS) has implemented Sellafield Limited’s arrangements for Licence Condition 22 (Modification or experiment on existing plant) and is compliant with the requirements of LC22.

Subject(s) of inspection

  • LC22 – Modification or experiment on existing plant – Rating: Green

Key findings, inspector’s opinions and reasons for judgement made

I, the Site Inspector for Spent Fuel Services (SFS), undertook a Licence Condition 22 (Modification or experiment on existing plant) inspection at the SFS Operating Unit at the Sellafield Site. The inspection focussed on seeking assurance that SFS was compliant with the Sellafield Limited arrangements for LC22.

Overall, I found that SFS, with the exception of one area, was compliant with the arrangements. Modifications were categorised appropriately, and where borderline were scrutinised by the appropriate committee, the correct due process had been followed for modifications, and personnel were demonstrated to have met relevant training requirements. My plant walkdown indicated that personnel on plant were aware of the status of the modifications and in the case of modifications to operating documentation were using the latest issue.

One area where SFS was non-compliant was in relation to temporary modifications, known as temporary plant interventions (TPIs). A significant number of these were overdue their allowed date; however, SFS was aware of these, and I concluded that the plant was safe; by their nature TPIs have the lowest safety significance. Nonetheless, this is a compliance shortfall, and I intend to address this by way of a level 4 regulatory issue.


With the exception of one area, TPIs, I was satisfied that SFS is compliant with the Sellafield Ltd corporate arrangements and compliant with the requirements of LC22. For the TPIs, I have raised a level 4 (lowest level) regulatory issue to address the matter. Noting that the shortfall is in relation to TPIs, and these are the least safety significant type of modification, I consider an inspection rating of Green (no formal action) to be proportionate and appropriate. The Head of Operations accepted my findings and observations at the wash up meeting.