Office for Nuclear Regulation

Sellafield – Inspection ID: 52426

Executive summary

Date(s) of inspection:

  • October 2023

Aim of inspection

The purpose of this inspection was to enable ONR to form a view on the claims made within the safety case on the pipebridges under the control of the Highly Active Liquor (HAL) facilities and verify that the key equipment is available and maintained.

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

This Intervention Record (IR) captures key regulatory observations made during a planned system based inspection (SBI) of the Highly Active Liquor Evaporation and Storage (HALES) facility Pipebridge systems. ONR’s System Based Inspection process examines evidence to determine compliance against six key licence conditions (LCs) 10, 23, 24, 27, 28 and 34.

For Licence Condition 10, I targeted the training of three Maintainers who carried out maintenance on the Pipebridge leak detection systems and reviewed the qualification and experience of the HALES Civil Engineering System Engineer. Overall, I judged that the required standard was met and an inspection rating of Green (no formal action) is appropriate against LC10.

For Licence Condition 23 and 24, I targeted the relevant Operating Rules (ORs), Referenced Operating Instructions (ROI), Operating Instructions (OI) and Emergency Instructions (EI) in connection with HALES pipebridge systems. Overall, I was satisfied that the safety case clearly identifies the fault sequences and that the operation and emergency instructions followed a detailed step wise format and contained the relevant steps to meet the safety case requirements. Based on the evidence sampled I judge that an inspection rating of Green (no formal action required) is merited against License Conditions 23 and 24.

For LC27, I targeted the relevant safety mechanisms in connection with the leak detection of radioactive liquor from the pipebridges. For LC28, I targeted the maintenance of the preselected safety mechanisms, the Inspection regimes (Civil and Camera) and the System Health Reports (SHR) in connection with the HALES Pipebridges. Overall, I judge that the HALES arrangements for maintenance and asset management of the pipe bridges are adequate and was satisfied that the condition of the pipebridges was known and appropriate measures are in place to refurbish and repair any minor problems. Based on the evidence sampled,  I judge that the required standard is met and an inspection rating of Green (no formal action) is appropriate against Licence Condition 27 and 28.

For LC34, I reviewed the potential for leakage and escape of radioactive material in connection with HALES pipebridges. Overall, I was satisfied that the appropriate measures were in place and judge that the required standard is met and an inspection rating of Green (no formal action) is appropriate against LC 34.

From the areas sampled, I provided some regulatory advice and observations but did not identify any shortfalls in the implementation of the licensee’s arrangements which would necessitate a further inspection of the Pipebridge systems earlier than currently planned.

Based upon the areas sampled I judge that the safety functions associated with the Pipebridge systems (which support the relevant claims in the safety case) under the control of the HALES have been adequately implemented.

Conclusion

From the evidence sampled during the inspection, I judge that HALES has adequately implemented the safety function of the Pipebridge systems  and that the formal arrangements for LCs 10, 23, 24, 27, 28 and 34 are being adequately implemented. For LCs 10, 23, 24, 27, 28 and 34 an inspection rating of Green (no formal action) is merited.