Office for Nuclear Regulation

Devonshire Dock Complex (Barrow) – Inspection ID: 52446

Date(s) of inspection

  • October 2023

Executive summary

Aim of inspection

In compliance with licence condition 11 (emergency arrangements), clause 5, BAE Systems Marine Limited (BAESML) undertakes an emergency arrangements demonstration exercise on an annual basis.  This was a planned intervention to evaluate the adequacy of implementation of BAESML’s LC11 arrangements through observation of the demonstration exercise, INDIGO 23.

Subject(s) of inspection

  • LC11 – Emergency arrangements – Rating: Green

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

On 11 October 2023, a team of ONR inspectors observed the level 1 demonstration exercise “INDIGO 23” at BAE Systems Marine Limited (BAESML), Barrow.  The letter is to confirm the overall conclusions of the ONR team as initially discussed at the feedback session. During the exercises I recognized the level of effort invested in running such demonstrations and have asked my thanks to all personnel involved in the planning, support, execution, and assessment of the demonstration be conveyed.

On the day, good interactions between teams were observed, particularly the interactions from and between the Strategic Team and Tactical Command Cell, which has improved since INDIGO 22 and 22R. Good team and individual competence across all areas was also demonstrated through the day. Use of written processes and ‘aides memoir’ was also observed and delivered positive results.


After considering the totality of the observations made by ONR inspectors (and others) on the day, 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.”

Full details of ONR’s (and others’) observations are provided in the letter BAE70124N.