Office for Nuclear Regulation

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Planned Systems Intervention to inspect the implementation of the nuclear safety case at the National Nuclear Laboratory Limited tenant facility

Executive summary

Purpose of intervention

A planned systems inspection was conducted, to inspect a number of key aspects of the implementation of the safety support systems arising from the nuclear safety case at the National Nuclear Laboratory Limited tenant facility, on the Springfields Fuels Limited licensed site.

Interventions Carried Out by ONR

National Nuclear Laboratory Limited (NNL) is a tenant organisation which operates a nuclear facility on the Springfields Fuels Limited licensed site. This planned systems inspection inspected the implementation aspects of the nuclear safety case. Aspects which I sampled during this inspection covered licence condition (LC) 10 (operator training), LC 23 (operating rules), LC 24 (operating instructions - alarm response), LC 27 (safety mechanisms), LC 28 (maintenance of safety mechanisms - the Maximo planned maintenance system) and LC 34 (containment, including hydrogen).

I initially held a meeting with a number of the licensee's and tenant organisation's key safety case staff, predominantly to discuss the arrangements for developing, updating and implementing the safety case.

I then inspected a number of pilot plant and laboratory facilities operated by NNL, (which are operated under the control and supervision of the licensee), speaking with operations and maintenance personnel, as well as inspecting sample training records, an alarm response instruction, examples of maintenance records and safety mechanisms. Containment measures were also inspected in the laboratories I also consulted a safety representative during this plant inspection.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

In my judgement, I concluded that the licensee had adequately developed arrangements for the compilation, maintenance and effective implementation of the nuclear safety case at the NNL facility.

I concluded that the safety case had been adequately implemented at the NNL facility, with a number of aspects which were observed to have been implemented to a good standard, including the identification and management of safety mechanisms, soundly derived from the safety case and the production of a good quality instruction for responding to an alarmed safety mechanism. Maintenance arrangements for safety mechanisms were found to be effectively prompted by the computerised planned maintenance system.

The plant inspection of a number of NNL laboratories and a pilot plant, together with discussions with a range of plant operating and maintenance personnel, who demonstrated an appropriate awareness of the key features of the safety case served to inform my judgement of the adequate implementation of the safety case.

Conclusions of Intervention

On balance, I concluded that the licensee's implementation of the nuclear safety case at the NNL facility was adequate, with some aspects of the safety systems being of a good standard.

The licensee's implementation of arrangements for the production of the nuclear safety case, including criticality safety and chemotoxic hazards, were also found to be effective. An active NNL safety representative was also consulted during the plant inspection, with a positive outcome.