Office for Nuclear Regulation

Sellafield – Inspection ID: 52389

Executive summary

Date(s) of inspection:

  • October 2023

Aim of inspection

For ONR to seek assurance on the adequacy of the implementation of the safety case for pond management at the Fuel Handling Plant (FHP). The intervention was justified in the ONR Spent Fuel Services Justification Document (2022/64238) and supports the ONR Sellafield Decommissioning, Fuel and Waste Advanced Gas Reactor Operating Programme Plan (2022/47759) and Regulatory Plan for the Management of Non-AGR Fuels at Sellafield (2023/29370).

Subject(s) of inspection

  • LC10 – Training – Rating: Green
  • LC23 – Operating rules – Rating: Green
  • LC24 – Operating instructions – Rating: Green
  • LC27 – Safety mechanisms, devices and circuits – Rating: Green
  • LC28 – Examination, inspection, maintenance and testing – Rating: Green
  • LC34 – Leakage and escape of radioactive material and radioactive waste – Rating: Green
  • Overall Inspection Rating – Rating: Green

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

The Fuel Handling Plant (FHP) at Sellafield is managed by the Spent Fuel Services Operating Unit. The pond (which comprises multiple ponds) within FHP is used to store various types of spent nuclear fuel including remnant MAGNOX and Advanced Gas Reactor (AGR) fuel. The aim of this system-based inspection was to determine the adequacy of the implementation of the pond water management safety case at the FHP. This was a joint inspection with the Environment Agency who sought to review the application of Best Available Techniques (BAT) to minimise the activity of radioactive waste produced on the premises; the Environment Agency will complete a separate report.

I found that relevant operating rules were defined in the clearance certificate and Sellafield Ltd was operating to these operating rules, however, several shortfalls were identified in relation to the assurance of the effectiveness of these operating rules, and I have raised two level 4 (lowest level) regulatory issues for the Licensee to address these shortfalls. Written instructions to support these operating rules were available and adequate, although in some instances the audit trail was difficult to follow.

Safety mechanisms, devices and circuits had been identified in the safety case and were being maintained in accordance with the relevant written schemes, although there were some minor anomalies with some of the sampled documents and records; I have provided regulatory advice on these matters to the Licensee.

I found that personnel responsible for delivering the requirements of the operating rules and maintenance item were trained, and appointed where necessary.

While on plant, I identified that housekeeping was below the standard I expect, and I have provided regulatory advice on this matter to the Licensee.

Overall, I was satisfied that the FHP safety case in relation to chemistry control has been adequately implemented and the SBI outcome merited a Green rating.


I am of the opinion that SFS has adequately implemented the safety case within the FHP; although some shortfalls were identified in relation to he assurance of the effectiveness of the operating rules; having consulted the ONR enforcement management model, I am satisfied that these are not serious, and can be addressed with the lowest level of regulatory issue  I have therefore awarded a Green rating (no formal action) for each of the LCs. I have raised two Level 4 regulatory issue (lowest level) in relation to pond water sampling and container monitoring, and provided regulatory advice for some other minor matters recorded in this intervention record.