Office for Nuclear Regulation

Sellafield – Inspection ID: 50543

Executive summary

Date(s) of inspection:

  • December 2022

Aim of inspection

In accordance with the Office for Nuclear Regulation’s (ONR) Sellafield Strategy, each year ONR performs a series of planned systems-based inspections (SBI) targeted on systems significant to safety to look at the implementation of the safety case.
The purpose of this SBI Inspection was to sample evidence of implementation of the safety case for the steam system at  the  Highly Active Liquor Evaporation and Storage (HALES) facility on the Sellafield site. This includes assessing   compliance with Licence Conditions (LCs) 10 (Training), LC23 (Operating rules), LC24 (Operating instructions), LC27 (Safety mechanisms, devices and circuits), LC28 (Examination, inspection, maintenance and testing) and LC34 (Leakage and escape of radioactive material and radioactive waste).

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

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

ONR carried out a planned two-day system based inspection on 7-8 December 2022 at the Sellafield Highly Active Liquor Evaporation and Storage (HALES) facility. The inspection focussed on the implementation of the HALES safety case in relation to the main and backup supplies of steam, which are needed by the facility even in a shutdown state. The inspection team comprised the Site Inspector for HALES and High Level Waste Plants (HLWP), Chemical Engineering Specialist Inspector, Internal Hazards Specialist Inspector and Fault Studies Specialist Inspector. The inspection included discussions with Sellafield Ltd personnel, a review of records, documents and processes and a targeted walk down of the facility.

From the evidence sampled, I judged that Sellafield Ltd had adequately implemented the safety case for steam and the following Licence Conditions (LC) were rated as GREEN (no formal action): LCs 10 (Training), 23 (Operating rules), 24 (Operating instructions), 27 (Safety Mechanisms, Devices and Circuits), 28 (Examination, inspection, maintenance and testing) and 34 (Leakage and escape of radioactive material and radioactive waste).


On the basis of evidence sampled during the inspection, I judge that Sellafield Limited has adequately implemented the safety case with regard to the HALES steam system and is compliant with the requirements of LCs 10, 23, 24, 27, 28 and 34. I have assigned an inspection rating of GREEN with respect to these LCs.

I am raising a Level 4 issue (lowest level)  in relation to Emergency Steam Generator inlet connections (pipework and valves connecting the boiler to the HALES steam ring-main). This   will  track a need for Sellafield Ltd to review the safety case claims, safety designation and resulting EIMT associated with the inlet connection valves on the HP supplies from the Emergency Steam Generators.