Office for Nuclear Regulation

Devonport Royal Dockyard – Inspection ID: 51977

Executive summary

Date(s) of inspection:

  • March 2023

Aim of inspection

The purpose of the intervention is for the ONR to inspect and determine the adequacy of implementation of DRDL formal arrangements for compliance with LC 11. This is an on-site re-demonstration targeting specific aspects of the site response following on from previous inspection of the LC11 Level 1 exercise.

Subject(s) of inspection

  • LC11 – Emergency arrangements – Rating: GREEN

Key findings, inspector’s opinions and reasons for judgement made

The Office for Nuclear Regulation (ONR) has undertaken an inspection to assess DRDL’s implementation of its LC11 – emergency arrangements. This was a re-demonstration exercise as the previous Level 1 emergency response demonstration exercise, in October 22, did not provide adequate evidence of implementation of the established emergency arrangements on the Devonport site, in respect of LC 11.

The intervention was undertaken and rated against published guidance on ONR’s expectations, as described in the technical inspection guides (TIGs), which can be found at Office for Nuclear Regulation (ONR) Compliance inspection – Technical inspection guides. Specifically, this included NS-INSP-GD-011 and ONR-INSP-GD-064.

Based on the evidence sampled at the time of the intervention against DRDL’s LC 11 arrangements and ONR’s guidance, I consider that DRDL did adequately demonstrate its arrangements across the areas sampled. I was satisfied that the exercise scenario was realistic and sufficiently challenging.

It is my opinion that the Level 1 emergency response re-demonstration exercise did provide adequate evidence of implementation of the established emergency arrangements on the Devonport site, in respect of LC 11, and that DRDL had implemented improvements following feedback on the previous inspection.  A Green rating is therefore considered appropriate, in accordance with ONR Guide ONR-INSP-GD-064.


ONR inspectors made observations at various locations during the exercise. DRDL were able to satisfactorily demonstrate improvements in the areas identified as part of the previous inspection.

The Defence Nuclear Safety Regulator (DNSR) also assessed the exercise demonstration and provided aligned evidence/observations, consistent with the approach of joined up regulation as did the DRDL Independent Nuclear Oversight team.

I noted that in DRDL’s self-assessment of the exercise they had suitably and accurately assessed themselves which aligned to the observations of the sites internal regulator and regulators. The prioritised observations from the sites internal regulator and regulators (ONR and DNSR) were fed back to DRDL as part of the “hot wash-up” meeting along with the judgement. This judgement concluded that based on the observations on the day, that the demonstration did satisfactorily demonstrate the sites emergency arrangements.