Office for Nuclear Regulation

Rolls-Royce Submarines Limited (RRSL) – Inspection ID: 50487

Date(s) of inspection:

  • November 2022

Aim of inspection

In compliance with licence condition 11 (emergency arrangements), clause 5, Rolls-Royce Submarines Limited (RRSL) undertakes an emergency arrangements demonstration exercise on an annual basis.  This was a planned intervention to evaluate the adequacy of implementation of RRSL’s LC11 arrangements through observation of an end-to-end test.

Subject(s) of inspection

  • LC11 – Emergency arrangements – Rating – Green

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

A team of four ONR inspectors observed RRSL’s emergency demonstration exercise ‘FOSSA’, making observations in the Emergency Control Centre (tactical), Bronze Command (operational), contact muster area, and technical cell, as well as observations of the deployed teams.

We observed good interaction between the Emergency Controller and the Deputy, good information flow into and through the Emergency Control Centre, and good use of technical resource to determine potential and actual hazards.  Some learning points were noted, relating to difficulty with radio communications, timeliness of board updating, and access issues which contributed to the slow rescue of the crush injury.  ONR sent a letter to RRSL shortly after the exercise with detailed observations from all aspects of the exercise to aid in RRSL’s continuous improvement.


I judge that this was an adequate demonstration of RRSL’s emergency arrangements, and therefore rate the 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.”