Office for Nuclear Regulation

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System Based Inspection (SBI) at AWE Aldermaston

Executive summary

Purpose of intervention

The main purpose of this intervention was to undertake a system based inspection (SBI) in the Main Production Facility at AWE Aldermaston, as per the Office for Nuclear Regulation’s (ONR) AWE Site Inspection Plan for AWE. The system inspected was Pyro-chemistry. In addition, during this planned ONR inspection week I conducted a number of other routine regulatory interactions on the AWE Aldermaston site.

Interventions Carried Out by ONR

Together with an ONR specialist mechanical engineering inspector, an ONR specialist internal hazards inspector and a member of the licensee’s own Internal Regulation Team (IR) – referred to as we in this report - a planned SBI on pyro-chemistry was conducted within AWE’s Main Production Facility. Through examination of this system we performed compliance inspections against a number of Licence Conditions (LC). In addition, during this ONR site inspection week I conducted a number of routine regulatory interventions with key licensee personnel.

Explanation of Judgement if Safety System Not Judged to be Adequate

The SBI was judged to be adequate.

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

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

Conduct of the intervention was via examination of licensee documentation and records, discussions with key plant personnel and by inspection of the relevant plant area(s). The key findings against each LC are recorded below:-

LC 10 (Training) – Green

We expressed some concerns that some of the individual processes, within the overall pyro-chemistry process, have only singleton trained personnel to conduct them. However, this is principally a business risk for the licensee, as it is the licensee’s policy not to conduct processes if no trained personnel are available. A training plan is in place to resolve this position. We were content with the licensee’s other training arrangements.

LC 23 (Operating Rules) – Green

We were satisfied that the licensee has an adequate process in place to define and specify Operating Rules, which is clearly linked to the safety analysis. We were content that the Operating Rules are being adequately implemented on the plant.

LC 24 (Operating Instructions) – Green

No issues requiring additional regulatory action arose from this part of our inspection.

LC 27 (Safety Mechanisms, Devices and Circuits) – Green

In our opinion the licensee has a clear definition of Safety mechanisms, Devices and Circuits (SMDC) and these are clearly identified in the licensee’s Safety Case on a Page documents. We sampled the maintenance records for two of the SMDC and found these to be in order.

LC 28 (Examination, Inspection Maintenance and Testing) – Green

Whilst we found the link between the Maintenance Schedule and the Safety Case hard to establish for the examples we sampled, we were nonetheless convinced that the ‘line of sight’ between the safety case and the maintenance schedule exists. We provided some minor advice on potential improvements to the maintenance instructions but overall were satisfied with this part of our inspection.

LC 34 (Leak and Escape of Radioactive Material and Radioactive Waste) – Green

The licensee demonstrated that it has adequate measures in place in manage any leak or escape of radioactive material from its pyro-chemical process.

The other routine regulatory interactions, conducted during ONR’s October 2016 site inspection week, are detailed within the body of this report. In all cases these interactions provided for a helpful exchange of information but did not identify any matters requiring further regulatory action/attention.

Conclusion of Intervention

After considering all the evidence provided by the licensee during the SBI, we consider that the pyro-chemistry system adequately meets the requirements of the safety case and there were no findings from our inspection that could undermine nuclear safety at this time.

For all the other interventions I conducted at AWE Aldermaston during ONR’s October Inspection Week no matters were identified requiring regulatory attention/action.