Executive summary
Date(s) of inspection:
January 2026
Aim of inspection
Assess the adequacy of the A4** arrangements and their implementation for Periodic Safety Reviews.
This Licence Condition 15 inspection will take place over one day.
The inspection will sample the adequacy of the Periodic Safety Review (PSR) for the A** facility, to allow ONR to establish whether the PSR has determined:
- The extent to which the A4** facility and its safety case conform to relevant UK nuclear industry good practice.
- The extent to which the safety documentation remains valid and reflects the current plant configuration to ensure that the claims, arguments and evidence are still appropriate and the risks are managed to ALARP.
- The adequacy and efficacy of the arrangements and structures, systems and components (SSC) in place to maintain safety until the next PSR or the end of life (which may include decommissioning).
- Safety improvements to be implemented to resolve safety issues identified in the PSR.
Subject(s) of inspection
LC15 - Periodic Review - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
ONR undertook a Licence Condition 15 inspection to judge the adequacy of implementation of AWE Nuclear Security Technologies (AWE) LC 15 arrangements.
The Inspection scope was to inspect the adequacy of the method and findings for the third Periodic Review of Safety (PRS3) of A** to establish if AWE had:
- Determined the extent to which the A4** facility and its safety case conform to relevant UK nuclear industry good practice.
- Determined the extent to which the A** facility safety documentation remains valid and reflects the current plant configuration to ensure that the claims, arguments and evidence are still appropriate and the risks are managed to ALARP.
- Determined the adequacy and efficacy of the arrangements and structures, systems and components (SSC) in place to maintain safety until the next PSR or the end of life.
- Identified safety improvements to be implemented to resolve safety issues identified in the Periodic Safety Review
To inform ONR’s judgement, the findings of PSR3 in the written evidence were examined and the method and findings from PSR3 discussed with those that had undertaken it. A walkdown of nuclear safety important tasks on the facility was also completed to confirm the way in which safety important tasks are undertaken and the condition of SSCs.
Against the scope and for the disciplines of Fault Studies, Human Factors, Mechanical Engineering and Radiation Protection, the inspection found that AWE had undertaken an adequate Periodic Review of Safety for the A** facility.
One shortfall to good practice was identified relating to the lack of Human Factors walkdowns of the facility. The absence of Human Factors walkdowns was not consistent with PSR3’s approach to Engineering, and not consistent with IAEA guidance for undertaking a Periodic Review of Safety (SSG-25). The findings of the ONR walkdown did not identify deficiencies to nuclear safety relating to this shortfall and therefore a level four regulatory issue was judged appropriate.
Two pieces of advice were identified. The first was associated with reliability of tasks to undertake fissile moves. The second was associated with recording and tracking the sentencing of PSR3 findings identified as observations or recommendations. Neither was deemed nuclear safety significant.
The inspection was rated GREEN in line with ONR’s General Inspection Guide (ONR-INSP-GD-064).
Conclusion
This inspection judged that AWE had undertaken an adequate Periodic Safety Review for the A** facility, compared to regulatory expectations and good practice.
The inspection was rated GREEN (No Formal Action)
This rating is in line with the established ONR guidance as follows:
- Relevant good practice generally met, or minor shortfalls identified, when compared with appropriate benchmarks.
The shortfalls and advice has been shared with the dutyholder. One level four regulatory issue has been raised (RI-12983.