Office for Nuclear Regulation

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Compliance inspections at AWE Aldermaston

Executive summary

Purpose of intervention

This report covers two interventions carried out as part of ONR’s regulation of operations undertaken at the Atomic Weapons Establishment. One intervention was held with the Mensa project to discuss progress against work identified during previous engagements. The other covered a reactive, unplanned Compliance Inspection undertaken on the Uranium Technology Centre (UTC) and focussing on UTC application of AWE’s Arrangements under LC14 (Safety documentation).

Interventions Carried Out by ONR

I attended AWE’s Aldermaston site to undertake a Licence Condition (LC) 14 (Safety documentation) Compliance Inspection. I also attended the Burghfield site to undertake an intervention on the Mensa project to progress work previously identified from Pre-Construction Safety Report (PCSR) 3.

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


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

Following the LC14 Compliance Inspection ONR found that AWE had achieved a ‘Below Standard’ IIS Rating for compliance against this LC. The scope of the Safety Case in preparation was not adequately defined. Also, the delivery programme appeared to have insufficient time allocated sufficient time for AWE to fully satisfy its Arrangements under LC14.

A positive meeting was held with the Mensa project regarding the way forward with the Forward Action Plan (FAP) items identified following the Mensa Pre-Construction Safety Report (PCSR) submission to ONR.  AWE agreed to ensure that individual FAPs would  signpost where in the final PCSR they were addressed.

Conclusion of Intervention

In my view, AWE need to review the delivery schedule associated with the revised Safety Case in the UTC to ensure that sufficient time is allocated to meet their requirements under LC14.  I will be progressing this matter as a Regulatory Issue.