Office for Nuclear Regulation

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AWE – Active Labs PRS Inspection  

Executive summary

The Active Laboratory analytical facility (A*.1) provides analytical services to other on-site facilities at the Atomic Weapons Establishment (AWE) Aldermaston site. The period of operation covered by the current Periodic Review of Safety (PRS1) for the Active Laboratory Facility ended during July 2017.

A preliminary familiarisation tour of the facility and initial safety case discussions between the Active Labs staff and ONR Fault Studies specialists suggest that this is a relatively low risk facility, that the risk of a public dose arising from this facility is small (below the BSO), and that the main risks arising are to the facility workers. 

Given the relatively low public hazards presented by this facility, the preferred and proportionate ONR assessment approach for the AWE Active Laboratory facility was by a focussed LC15 (the requirement to undertake Periodic Safety Review of the safety case) inspection, informed by the PRS submission documents, and supported by ONR specialist inspectors, either at the inspection or by provision of specialist subject matter question sets formulated prior to the inspection.

Purpose of Intervention

The purpose of this intervention at (AWE) was to perform a focussed LC15 inspection, informed by:  

The further aim of the intervention was to facilitate an informed view on the adequacy of the PRS2 submission and proposed fixes to reduce risks ALARP. The inspection (and discussions) included sampling of plant, processes and people in the context of the PRS2 submission. This intervention also focussed on the implementation of the FAP and current progress with remediation of the shortfalls associated with the highest risk faults.

The inspection was undertaken in accordance with ONR’s Operating Facilities Division Weapons Sub-programme Strategy 2018 - 2020 for the Atomic Weapons Establishment Programme. The Weapons Sub-programme Strategy 2018 - 2020 defines four strategic aims and their anticipated outcomes and milestones. The relevant strategic aim here is that AWE produce: ‘Fit-for-purpose safety documentation which is available to support AWE and ONR objectives.’

The inspection undertaken forms part of a series of planned interventions in accordance with the Operating Facilities Division Weapons Sub-division Strategy 2018 - 2020 and the ONR AWE Inspection Plan April ’18 - March ’19.

Interventions Carried Out by ONR

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

In addition to conducting a visual inspection of specific areas of the facility, we attended a series of detailed presentations from AWE on the Active Labs PRS2 submission and its implementation. We also held detailed discussions on the highest risk faults and progress with addressing shortfalls against these faults. The specialist areas discussed in the licensee presentations are given in further detail in the body of this Intervention Report.

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

This was a successful and proportionate intervention with good cooperation between ONR and AWE facility staff. A detailed agenda and specialist question set was provided to the licensee in advance to facilitate a more efficient and focussed inspection. The inspection and associated discussions/presentations from the licensee revealed that AWE had undertaken a pragmatic PRS review which resulted in the identification of a number of key shortfalls. Progress is ongoing with the implementation of engineered protection measures on the shortfalls associated with the highest risk faults.

Our inspection and discussions with the licensee did not reveal any matters of substantive safety concern. However, some observations on housekeeping in plant areas were fed back to the licensee, who accepted their validity with respect to increased fire loadings and potential ignition sources in the facility. A regulatory issue has been raised against some of the findings relating to the ventilation system.

Conclusion of Intervention

Based on the PRS2 documents sampled prior to the inspection, evidence presented by the licensee and ONR’s visual inspection of the facility, the inspection is given a provisional rating of green – ‘Adequate’. No significant safety concerns were identified other than the observations on housekeeping which the licensee fully acknowledged, with a view to quickly removing the redundant items giving rise to increased fire loading/additional ignition sources within the facility.

Good ongoing progress is being made by the licensee on implementing engineered protection measures on the PRS shortfalls associated with the five highest risk faults, which give rise to ~97% of the total facility risk. The ONR view is that this is a focussed and proportionate approach by the licensee to reducing risks ALARP on this facility. Some areas arising from the inspection that require clarification will be addressed as part of ONR’s routine interactions with the facility. These areas of clarification are unlikely to alter the overall inspection rating of ‘Adequate’.