- Site: Sizewell B
- IR number: 19-037
- Date: June 2019
- LC numbers: 9, 26
Executive summary
Purpose of Intervention
The purpose this intervention was to carry out a planned licence condition (LC) 26 (control and supervision of operations) inspection in accordance with the Sizewell B integrated intervention strategy (IIS) plan. While on site, I also had the opportunity to witness the outage-specific induction training and to follow that training up with outage personnel, and have used this as the basis for an unplanned LC 9 (instructions to persons on site) inspection.
Interventions Carried Out by ONR
During an outage, the plant configuration is very different from normal operation. I considered the processes by which the Shift Manager, as duly authorised person (DAP), maintains control of the plant configuration through the use of minimum essential equipment lists and protected trains of equipment, and by authorising mode changes. I also inspected the control and supervision of outage personnel in containment and around the site more generally.
I also undertook the outage-specific induction training, and followed up some of the key messages from the training with outage personnel to test whether those messages had been received and understood.
Explanation of Judgement if Safety System Not Judged to be Adequate
N/A
Key Findings, Inspector's Opinions and Reasons for Judgements Made
I inspected a number of work fronts, both inside and outside of containment. I spoke to outage workers and supervisors, and the Shift Manager, and sampled the licensee’s procedures and operational documentation for control and supervision and for outage training. Overall, in the areas sampled I consider:
- That the Shift Manager, by virtue of the outage planning process (which reviews the outage plan against minimum essential equipment requirements), the mode change process, the procedure for protecting trains of equipment, and the shift surveillances that confirm adherence to the above, is able to maintain appropriate control over, and supervision of, the plant configuration throughout the outage. The shift handover process is thorough and allows the incoming Shift Manager to gain a robust appreciation of the current plant state and operational focus.
- Plant-level control and supervision is appropriate, with a good understanding of outage-specific hazards and controls being demonstrated.
- The outage-specific induction training to be exemplary. The classroom sessions focussed on areas of particular risk during an outage, and made good use of operating experience from Sizewell B and other power stations to emphasize the need for the controls in place. These sessions were supported by a detailed walkdown of a plant mock-up, so that examples of hazards and controls could be demonstrated in a safe manner. It was clear to me from speaking to outage personnel that the messages from the training had been embedded in those individuals.
Conclusion of Intervention
Overall, I consider that the licensee is able to demonstrate compliance in the areas inspected. Therefore, no urgent regulatory action is needed and no change to the planned intervention strategy for Sizewell B is required.