Office for Nuclear Regulation

LC28 and LC26 Site Steam System intervention

Executive summary

Purpose of Intervention

The key aims of this reactive intervention was to inform ONRs opinion as to the adequacy of AWE’s compliance with Statutory Instruments, LC28 (Examination, Inspection, Maintenance and Testing – EIMT) and LC26 (Control and Supervision of Operations) associated with the site utilities steam main, following steam system events in August and November 2020. Investigation Decision record ONR-IDR-20-012 [Ref 1] contains further details in support of this intervention.

This inspection was carried out on the site steam ring main at AWE Aldermaston.

There is currently no safety case for the AWE Aldermaston site which covers site utilities. The site steam main has no direct link to nuclear safety; however, it does provide services to both nuclear and non-nuclear facilities.

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A – this was not a systems-based inspection.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

From the evidence sampled during this inspection I judged that there were no significant LC28 shortfalls that could impact safety.
Conclusion of Intervention

This intervention sought to confirm the adequacy of Statutory Instrument compliance, LC28 (Examination, Inspection, Maintenance and Testing – EIMT) and LC26 (Control and Supervision of Operations) including Regulation 5 of MHSWR 1999 associated with the site utilities steam main, following steam system events in August and November 2020. It also served to inform the ONR investigation decision record as to whether it was proportionate to investigate.

Overall, I was content that the areas sampled during this intervention provided confidence that EIM&T and its associated supervision where being adequately implemented in line with AWE arrangements, as described during the intervention.

I was also satisfied that the AWE’s statutory inspections relating to PSSR WSEs and their associated record keeping were adequate.

The intervention highlighted two specific areas for the licensee’s consideration as opportunities for further improvement, namely:

To conclude I was satisfied based on the review of the documents sampled and walkdowns performed during this intervention that AWE’s compliance with Statutory Instruments, LC28 and LC26 including MHSWR 1999 Regulation 5 was demonstrated as adequate on this occasion.

I am therefore content that a rating of Green is appropriate for all aspects of the intervention.