- Site: AWE Burghfield
- IR number: 21-146
- Date: February 2022
- LC numbers: 10, 23, 24, 27, 28
Executive summary
Purpose of Intervention
The Office for Nuclear Regulation (ONR) undertakes all regulatory interventions with the Burghfield nuclear site licensee, AWE plc (AWE) against a strategy defined by the ONR Weapons sub-Division. In accordance with that strategy and ONR’s General Inspection Guide, a system-based inspection (SBI) was undertaken on the Assembly Technology Centre (ATC) on the 9th and 10th February 2022.
The purpose of this intervention was for the ONR to determine the ability of the lightning protection system (LPS) to deliver the safety functions placed upon it. This was done by inspecting AWE’s implementation of its arrangements for licence conditions (LCs) 10, 23, 24, 27 and 28 for the selected system. LC 34 was excluded from the scope as it is not directly relevant to the system and is covered by more applicable ATC SBIs.
Interventions Carried Out by ONR
The intervention focussed on the people, processes and plant that the ATC has in place to comply with the relevant LC arrangements for the selected system and was undertaken via desktop discussions and facility inspection. This included semi-structured interviews with relevant AWE personnel; sampled review of relevant documents and records; and inspection of plant/equipment.
The intervention was undertaken and rated against published guidance on ONR’s expectations, as described in ONR’s technical inspection guides (TIGs), which can be found at the ONR external website. The relevant good practice benchmark against which ONR’s judgement was made specifically used current revisions of TIGs NS-INSP-GD-010, 023, 024, 027 and 028. The intervention was rated in accordance with ONR ‘General Inspection Guide’, ONR Ref. ONR-INSP-GD-064.
Explanation of Judgement if Safety System Not Judged to be Adequate
Based on the evidence sampled, AWE was judged to be implementing adequately the relevant LC arrangements for the LPS thereby demonstrating that it fulfils its safety functions.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The intervention targeted implementation of the LPS operating rules, specifically those delivered via maintenance activities. This included sampling the adequacy of instructions, previous activities, LPS condition and personnel training to deliver these activities. Based on the sample reviewed, the related evidence was adequate to demonstrate compliance with AWE’s arrangements and regulatory expectations.
Conclusion of Intervention
Based on evidence sampled at the time of this inspection, I judge that AWE is implementing adequately its formal arrangements for compliance with LCs 10, 23, 24, 27 and 28 for the LPS thereby demonstrating that it currently fulfils its safety functions.
I therefore consider that an inspection rating of Green (No Formal Action) is merited, in accordance with ONR Guide ONR-INSP-GD-064, where relevant good practice was generally met, when compared with appropriate benchmarks and compliance arrangements. No significant shortfalls were identified in the delivery of safety functions.
During the inspection there were no regulatory findings (ONR Regulatory Issues) identified in respect of LCs 10, 23, 24, 27 and 28 nor regulatory observations (‘ALARP’ improvements) made in respect of LCs 10, 23, 24 and 28. One regulatory observation was made in respect of LC 27 associated with AWE investigating the potential for surge protection devices to have unrevealed failures.