Executive summary
Date(s) of inspection: January 2025
Aim of inspection
This inspection follows the regulatory strategy set out in PR-01576 and follows on from ONR's assessment of the safety case for the proposed operations prior to installation activities (Pre-Construction Safety Report (PCSR)) and review of significant design changes, captured in the Pre-commissioning Safety Report (PCmSR), prior to inactive commissioning. ONR also undertook an LC21/22 inspection in response to RRSL's request to move into active commissioning without having completed all inactive commissioning and without the Nuclear Protection System (NPS) in 2023. This inspection was focused specifically on a modification proposed by RRSL that introduced a new fault sequence and new claims on human Safety Actions (IR-52845).
The aim of the current inspection is to gain regulatory confidence in RRSL’s readiness to commence Phase 2 Active Commissioning activities at Dreadnought Production Facility in order to release an EIM&C hold point.
Subject(s) of inspection
- LC21 - Commissioning - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
RRSL entered into Phase 1 Active Commissioning in 2023, whereby it introduced and processed a subset of items prior to commissioning the nuclear protection system. In phase 2 active commissioning, RRSL will introduce and process items containing larger quantities of fissile material, which has the potential to result in advertent criticality under certain fault conditions and therefore claims the nuclear protection system to protect against this, as well as claims on human actions. Phase 2 active commissioning includes processing these items multiple times before entering operations.
This inspection judged the adequacy of RRSL's implementation of its arrangements for Licence Condition (LC) 21, specifically the readiness of the people, plant and processes to undertake these activities. Its purpose was to inform the release of an EIM&C hold point for phase 2 active commissioning of DPF Wetside.
We judged that RRSL demonstrated adequate compliance against LC21 and readiness to enter phase 2 active commissioning, such that the hold point can be released. The inspection was rated as GREEN (no formal action).
Conclusion
We judged that RRSL has adequately implemented its LC21 arrangements and demonstrated readiness to proceed to phase 2 of active commissioning. In particular, RRSL demonstrated it had
- provided adequate documentation to justify the safety of proposed activities;
- provided evidence that the nuclear protection system has been commissioned;
- provided suitable training for those on the facility who have responsibility for any operations which may affect safety;
- provided operating instructions that include instructions in the interests of safety and instructions necessary to ensure operating rules are implemented.
Therefore, the inspection was rated GREEN (no formal action) in accordance with ONR Guide ONR-INSP-GD-064.