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Magnox Ltd Harwell System Based Inspection

  • Site: Harwell, Winfrith
  • IR number: 19-182
  • Date: March 2020
  • LC numbers: 10, 23, 24, 27, 28, 34

Executive summary

Purpose of Intervention

This inspection on the Harwell licensed nuclear site was undertaken as part of a programme of planned interventions as outlined in the Magnox Ltd southern sites’ inspection plan for 2019/20.

Interventions Carried Out by ONR

During this systems based inspection I examined the arrangements related to the B462 Dragon waste retrieval interlock system to ensure adequate implementation of the following licence conditions:

  • LC10 Training
  • LC23 Operating rules
  • LC24 Operating Instructions
  • LC27 Safety Mechanism, Devices and Circuits
  • LC28 Examination, Inspection, Maintenance and Testing

The inspection comprised plant inspection, office-based examination of procedures and records and interviews with staff

Whilst on site I held a meeting with the licensee to discuss progress with the Harwell and Winfrith Waste Improvement Programme.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not Applicable. 

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

I carried out a System Based Inspection to assess the implementation of arrangements in relation to the B462 Dragon waste retrieval interlock system. During this inspection, I reviewed the licensee’s safety case and considered that it accurately represented the facility and identifies the associated hazards and risks. In my opinion the safety case also identified appropriate safety related equipment.

I reviewed the training records for a sample of operational and maintenance staff. I found that all such persons had current training records against all of the operating and maintenance instructions sampled during this inspection. I reviewed a number of applicable operating and maintenance instructions, and found that they were clear and concise and identified references to the safety related equipment.

I found that the licensee is undertaking suitable maintenance and testing activities for the interlock system.  All maintenance records sampled were within date and legible. The licensee also demonstrated that the plant was not operated, unless the safety mechanisms, devices and circuits were functioning and in good working order.

Conclusion of Intervention

Based on the evidence gathered during this inspection, I consider that the licensee has made and implemented its arrangements adequately to ensure the B462 Dragon waste retrieval interlock system fulfils the requirements of the safety case.