- Site: RRSL
- IR number: 21-130
- Date: November 2021
- LC numbers: 22
Executive summary
Purpose of Intervention
This was a planned intervention to evaluate the adequacy of Rolls-Royce Submarines Limited’s (RRSL) arrangements for licence condition (LC) 22 (‘Modification or experiment on existing plant’) at the Raynesway nuclear licensed sites.
Interventions carried out by ONR
The intervention was conducted on-site by the ONR nominated site inspector for the Raynesway nuclear licensed sites, utilising relevant good practice from ONR-INSP-GD-022 revision 6. The intervention was focused on the updated arrangements, which had been received prior to the intervention.
Key findings, inspector's opinions and reasons for judgements made
RRSL has implemented revised working-level arrangements for compliance with LC22. I consider them to meet the regulatory expectations of NS‑INSP‑GD-022 revision 6. The arrangements have been split from those pertaining to LC20, as well as the overall process having been streamlined and additional clarity brought to them.
I judge that accountability for safety case ownership moving to the Heads of Manufacturing/Pre-Production and the subsequent delegations to the Technical Support Managers/Facility Manager, and those individuals now forming the governance backbone of the change management process will increase the level of direct oversight of all potential modifications.
RRSL has made excellent progress on reducing the number of longstanding modifications through focusing of resource and making use of the newly introduced arrangements. In my opinion this reduces the chances of future events/incidents relating to LC22.
Conclusion of intervention
Based on the sample inspected, I rate the LC22 intervention as GREEN – ‘No Formal Action’. This rating is in line with the established ONR guidance:
- “Relevant good practice generally met, or minor shortfalls identified, when compared with appropriate benchmarks.”
- “No significant shortfalls identified in the delivery of safety, safeguards or security functions.”
The level 3 regulatory issue (7286) will be proposed for closure on the basis of the revised arrangements having been issued, training having commenced, and the number of longstanding modifications reduced.
Given the GREEN rating awarded, and the proposal for closure of the associated regulatory issue, I consider the matter in enforcement letter ONR‑EL-21-021, ‘Oxide Dissolver Fault Sequence Near Miss’ issued on 15 September 2021 to be closed.
Annual LC22 compliance inspections will continue at RRSL, with the next inspection planned for August 2022 to follow with RRSL’s planned formal review of the categorisation process.