Office for Nuclear Regulation

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Urenco UK Ltd Enrichment Facility. Inspection of alarm management

Executive summary

Purpose of intervention

This was an unplanned intervention targeted at alarm management at the latest enrichment facility on the Urenco UK Limited, Capenhurst, nuclear licensed site.

Interventions Carried Out by ONR

The enrichment facility inspected is the most modern of the three enrichment facilities at the Capenhurst site. The plant has been extended several times since the original plant was commissioned in the late 1990s. However, there is a central control room (CCR) for the entire plant.

All alarms generated by the plant initiate in the CCR. This intervention was focused on alarm management in the CCR. Findings were considered against the requirements of License Condition 24 (Operating Instructions) in addition to the ONR Guide on Safety Related Instrumentation.

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

The key finding is that there are significant shortfalls with the alarm management system. Specifically, the way alarms are presented to the operator may not enable the operator to determine the correct plant state, and there are no written instructions available to the operator for alarm response. Therefore, some of the requirements of the ONR Guide "Safety Related Instrumentation" are not being met. Additionally, the requirement of Licence Condition 24(1) is not being met. However, the licensee has recognised that improvement in alarm management is required and this is supported by an improvement programme.

Conclusion of Intervention

I have rated this intervention as amber under the ONR Inspection Rating Guide due to the shortfalls identified. I am satisfied that the improvement programme is adequate with respect to making the necessary improvements to the shortfalls identified with the exception of the written instructions for operator response to alarms. I will inform the licensee in writing of the improvements required in compliance with Operating Rule 24(1) to address this issue.