Executive summary
Date(s) of inspection
- May 2026
Aim of inspection
This inspection will assess the adequacy of Sellafield Limited’s pressure system management arrangements within the High Level Waste Plant, including a review of the condition of the physical assets. It will seek assurance that there is adequate inspection, maintenance and oversight of pressure systems and will involve targeted sampling of the arrangements for compliance with the Pressure Systems Safety Regulations (PSSR) 2000.
Subject(s) of inspection
- PSSR - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
The High Level Waste Plant (HLWP) is a key facility in the processing of high-level waste and encompasses an number of pressure systems. The management of pressure systems and compliance with the Pressure Systems Safety Regulations (PSSR) 2000 remains a regulatory focus across all ONR-regulated facilities. Sellafield Limited have independently identified PSSR compliance as one of the HLWPs top three risk areas.
The purpose of this intervention was to seek assurance on the adequacy of Sellafield Limited’s pressure system management arrangements within the High Level Waste Plant, including a review of the condition of the physical assets.
We sampled the implementation and delivery of PSSR compliance, including a review of Written Schemes of Examination (WSE), maintenance records, statutory inspections, and discussions with responsible engineers, supported by a targeted walkdown.
Sellafield Limited demonstrated a good understanding of PSSR requirements, and appropriate engagement with their design authority.
Arrangements for oversight, including statutory meetings and health reporting tools, were in place and provided visibility of system condition and work prioritisation.
Maintenance instructions sampled were of good quality; however, shortfalls were identified in the completion of Asset Condition Assessments (ACA) for key systems and the development of a fully defined Technical Basis of Maintenance (TBoM), with current maintenance based on generic assumptions rather than system-specific risk.
There is an ongoing level 3 regulatory issue (RI-11456) regarding the defect backlog with HALES and HLWP, from the evidence sampled this regulatory issue remains valid.
Conclusion
The HLWP facility at Sellafield Limited have demonstrated the adequacy of their arrangements for PSSR 2000 and Asset Management warranting an intervention rating of GREEN (no formal action).
Upon consideration of the ONR guidance on inspection ratings, I judge that a rating of GREEN (no formal action) is appropriate for the evidence sampled.
I provided feedback to Sellafield Limited on the inspection findings at the close-out meeting on site.
In terms of the steam system maintenance shortfall identified, I will consider the appropriate enforcement actions and associated corrective actions through application of the ONR Enforcement Management Model.