Executive summary
Date(s) of inspection: December 2023
Aim of inspection
This intervention was undertaken across the Atomic Weapons Establishment (AWE) Explosives Technical Centre (XTC) and aligns with the Office for Nuclear Regulation (ONR) 2023/24 integrated intervention strategy for the weapons sub-division. The below key sub-division objective (KSO) and key regulatory objectives (KRO) are considered most relevant:
- KRO.5 Provide assurance to our stakeholders that hazardous activities on site are planned and conducted safely in accordance with the appropriate legislative requirements and that all risks have been reduced to as low as reasonably practicable.
- KRO.5.4 ->Continued collaboration with Health and Safety Executive (HSE) to deliver the effective regulation of the explosives’ portfolio.
- KSO.3 - Demonstrate effective collaboration with other principal safety regulatory authorities to enable the efficient joint regulation of the AWE sites.
The main aim of this inspection was to ensure that AWE is compliant with the safety provisions of the Explosives Regulations (ER2014), and that risks are being adequately controlled and managed so far as reasonably practicable.
This engagement aims to:
- Assess the adequacy of arrangements and working practices to ensure that appropriate safety measures are identified and implemented to ensure compliance with the regulations.
- Obtain evidence that the arrangements are being adequately implemented to control manufacture (e.g., powders and mixing) and storage operations.
- Obtain evidence that appropriate general precautions (e.g., compliance with explosive licences, selection of appropriate tooling, electrostatic discharge precautions, cleanliness, lightning protection) are in place with respect to places of manufacture, processing and storage.
- Obtain evidence that adequate maintenance systems are in-place and implemented across identified safety-critical systems.
Subject(s) of inspection
- Explosive Regulations 2014 - Rating: Green
- LC23 - Operating rules - Rating: Green
- LC24 - Operating instructions - Rating: Green
- LC27 - Safety mechanisms, devices and circuits - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
A team of Inspectors attended the AWE site and undertook a compliance inspection across the Explosives Technical Centre (XTC). The primary focus of the intervention was to ensure compliance with the Explosives Regulations 2014. In addition, compliance with the requirements of relevant Licence Conditions (LCs) was also considered.
This intervention was planned and performed in line with ONR’s guidance (as described in our inspection guides, which can be found at (Office for Nuclear Regulation (ONR) Compliance inspection - Technical inspection guides).
In order to form judgements on the adequacy of AWE's arrangements and their implementation, the intervention comprised an overview of the related arrangements, a series of plant walkdowns and a review of evidence. No explosive processes were being undertaken at the time of the intervention. The sample chosen was risk informed and intelligence led. The main points recorded against the areas sampled are summarised as follows:
- Control room for remote operations - The measures and processes in-place to control remote activities were judged to be adequate with elements of good practice observed.
- Powder production - Adequate general precautions consistent with the hazard were observed. Related arrangements and requirements were being implemented and records kept.
- Decanting/drying - Work place risk assessments were sampled and judged to be adequate with minor shortfalls identified. The assessment process implemented to control the deployment of non-justified workers in the adjacent construction enclave was reviewed and judged to reflect the requirements of the arrangements with control measures clearly articulated.
- Tray blending - The facility was observed to be in a relatively poor general condition and a related minor shortfall was recorded. However, appropriate controls were described for the process as currently implemented and it is recognised that this process is currently under review and improvements are planned prior to future use.
- Magazine stores - Explosive designated location signage and explosive safety orders were observed in lobby locations. Stored quantities were confirmed as being within the defined limits of the licence and explosive safety order. The lobby areas were observed to be in need of repainting with significant amounts of flaked paint. The flooring in some areas of the magazines was also deteriorating with some obvious cracks and crevices identified. A minor shortfall was recorded with respect to the condition of the individual magazine electrical junction box indicator lights.
- Risk Assessments – Several risk assessments were examined and were generally considered to be of a good standard with some minor shortfalls identified. Additionally, some inconsistencies were observed in how the assessments had been completed, this was potentially due to changing practice over time.
- Licence compliance – The arrangements in place, principally the use of explosive safety orders and the restrictions to quantities of explosives imposed by the process design were judged to be adequate.
Conclusion
Overall, based on the evidence sampled during this intervention, it is judged that:
- Arrangements are appropriate and being adequately implemented to control manufacture.
- Appropriate general precautions are in-place with respect to manufacture, processing and storage.
- Adequate maintenance systems are in-place and being implemented across safety-critical systems.
In addition to the above, nothing was observed during the conduct of the inspection that significantly undermined confidence in compliance with the Explosives Regulations. Relevant good practice was considered to be generally met with minor shortfalls (see Observations) identified when compared with appropriate benchmarks. It is expected that the Licensee will address the minor shortfalls and manage resolution via their internal management controls.
With respect to the Licence Conditions, aspects relating to LC 23 (Operating Rules), LC 24 (Operating Instructions) and LC 27 (Safety Mechanisms, Devices and Circuits) were sampled. It was possible to follow the 'golden thread' through from the 'top level' explosive site licences (that define the limits and requirements) through to the lower level working arrangements and controls. The lower level arrangements sampled comprised the explosive safety manual requirements, process and operating instructions and work based risk assessments, which were judged as being be adequately implemented to control activities. Some elements of good practice were identified in relation to the behaviours demonstrated and the use of an interactive operation delivery board. From an LC 27 perspective, maintenance checks and tests associated with the lightening protection systems were sampled and judged to be complete. No significant shortfalls were identified in the delivery of safety with minor areas for improvement identified (see Observations). Green ratings were awarded against LC 23, LC 24 and LC 27 in accordance with ONR's Inspection Ratings Guide - No Formal Action.