Office for Nuclear Regulation

Sellafield Site – Inspection ID: 52324

Executive summary

Date(s) of inspection:

May 2023

Aim of inspection

The aim of this planned compliance inspection is to judge Sellafield Ltd’s compliance with the requirements of Nuclear Safeguards (EU Exit) Regulations 2019 (NSR19), particularly the adequacy and implementation of their arrangements for a physical inventory take (PIT).

Subject(s) of inspection

  • FSE 1 Leadership and Management for NMACS – Rating: GREEN
  • FSE 8 Data Processing and Control – Rating: GREEN
  • FSE 9 Material Balance – Rating: GREEN
  • NSR19 Reg06 – Accountancy and control of qualifying nuclear material – Rating: GREEN
  • NSR19 Reg09 – Operation of an accountancy and control plan – Rating: GREEN
  • NSR19 Reg10 – Operating records – Rating: GREEN
  • NSR19 Reg11 – Accounting records – Rating: GREEN
  • NSR19 Reg15 – Material balance report and physical inventory listing – Rating: GREEN

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

ONR Safeguards inspectors conducted a planned compliance inspection on 17 May 2023 the Sellafield nuclear licensed site, operated by Sellafield Ltd. The inspection targeted implementation of Sellafield Ltd’s arrangements for a physical inventory take (PIT) at the following material balance areas (MBAs):

  • QS10 – Fuel Handling Plant (FHP) – Magnox Fuel Storage Pond
  • QS21 – FHP – Advanced Gas Reactor (AGR) Fuel Storage Pond

The inspection was performed in line with relevant ONR’s guidance, which can be found on ONR’s website (

The inspection involved a planning phase and a one‑day site visit, including plant walkdowns, discussions with relevant Sellafield Ltd personnel, review of records, and sampling of information contained within electronic databases and other documentation.

Overall, I was satisfied that Sellafield Ltd has provided adequate level of assurance and evidence to demonstrate compliance with the requirements of NSR19 and regulatory expectations.

I identified a shortfall under NSR19 Regulation 6, related to the absence of written arrangements for a PIT in the MBAs QS10 and QS21. I judge this to be a minor shortfall. Based on the evidence I have seen and discussions with Sellafield Ltd staff, I am satisfied that the PIT is carried out in an appropriate way. The staff members were able to explain what they did and presented evidence of the PIT undertaking. I note that a recent Sellafield Ltd internal assurance audit had already identified this shortfall and have taken steps to initiate a resolution. I am raising a level 4 regulatory issue to monitor Sellafield Ltd’s progress for resolving absence of local PIT procedures in the Fuel Handling Plant.

I have also observed a few minor inconsistencies between written arrangements and their implementation and reflected these in regulatory advice provided to Sellafield Ltd.


Overall, based on my inspection sample, I judge that Sellafield Ltd is implementing physical inventory takes (PIT) in the MBAs QS10 and QS21 in accordance with regulatory expectations FSE 1.2, FSE 8 and FSE 9.2 and in compliance with NSR19 Regulations 6 (including Schedule 2), 9, 10, 11, 15 and 20.

Upon consideration of the ONR guidance on inspection ratings, I judge that a rating of GREEN (no formal action) is appropriate.

I provided feedback to Sellafield Ltd on the inspection findings at the close-out meeting onsite.