Hinkley Point B site intervention
- Site: Hinkley Point B
- IR number: 15-079
- Date: September 2015
- LC numbers: 10, 23, 24, 27, 28, 34
Purpose of intervention
This was a planned inspection of EDF Energy Nuclear Generation Ltd’s (NGL’s) Hinkley Point B power station, undertaken as part of the planned intervention strategy for the Civil Nuclear Reactor Programme (CNRP) of the Office for Nuclear Regulation (ONR).
The work was carried out in line with the planned inspection programme contained in the Hinkley Point B Integrated Intervention Strategy (IIS).
Interventions Carried Out by ONR
I (the nominated site inspector for Hinkley Point B) with an Electrical Technical Specialist from AMEC Foster Wheeler carried out a System Based Inspection (SBI) on No‑break electrical supplies. I subsequently:
- Carried out a licence condition 25 (operational records) compliance inspection.
- Discussed key matters with the site internal regulator.
- Held a number of information exchange meetings with station staff.
Explanation of Judgement if Safety System Not Judged to be Adequate
Not applicable – the system was judged to be adequate.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
From the system based inspection on the No-break electrical supplies we concluded that:
- LC 10 (Training) – We examined the role profile and training records for a sample of the personnel involved in the maintenance of the No-break supplies. The evidence identified the essential training requirements for each role profile and we found that all essential training was in date. We therefore assigned an IIS rating of 3 (adequate) to this inspection.
- LC 23 (Operating Rules) – The licensee’s Operating Rules were contained within its Technical Specifications and were well defined for the No-break supply systems we examined. We found that unplanned entries to Technical Specification action conditions were infrequent. We examined the 240 V dc battery system in detail and identified a comprehensive set of Technical Specification compliance requirements including defined surveillances which were carried out by each shift. We therefore assigned an IIS rating of 3 (adequate) to this inspection.
- LC 24 (Operating Instructions) – We asked the licensee for operating procedures for normal & emergency operation of the Gas Circulator & Safety Motor Generator sets. We also looked at the Maintenance Schedules and procedures for these systems and the 240 V dc batteries. The supplied documentation was of a good quality and followed the standard formatting and layout. The Station personnel demonstrated a sound understanding of the equipment and the maintenance requirements. We assigned an IIS rating of 3 (adequate) to this inspection.
- LC 27 (Safety Mechanisms, Devices and Circuits) – We judged that the No‑break supplies were properly connected and in good working order. We considered that the documentation accurately reflected the as-built plant and that the plant was being regularly monitored, inspected and maintained. We noted that the No-break supplies system performance statistics indicated a reliable system and following discussions with plant personnel it was clear that obsolescence was being adequately managed. We therefore assigned an IIS rating of 3 (adequate) to this inspection.
- LC 28 (Examination, Inspection, Maintenance and Testing) – We reviewed the maintenance work instructions and work orders for the 240 V dc battery 3A and followed the application of the LC28 processes which lead to the replacement of the battery system. We noted the Information Technology systems that had been developed to plan, track, execute, record the results and derive trends/system health statistics. Given the quality of the LC28 process management and the extensive experience and expertise of the NGL staff responsible for the maintenance of the No‑break supplies, we assigned an IIS rating of 2 (good) to this inspection.
- LC 34 (Leakage and Escape of Radioactive Material and Radioactive Waste) – We established that LC34 was not applicable to the No-break supplies, and therefore no assessment was made against this LC.
Overall, we concluded that the arrangements and their implementation on the No‑break electrical supplies met the requirements of the safety case and were deemed to be adequate.
I (the nominated site inspector) carried out the following inspections:
For licence condition 25 (operational records) - I was satisfied that site had developed adequate procedures and facilities for the making and retention of records relating to operations on the site. I therefore assigned an IIS rating of 3, (adequate) to this inspection.
I met with the Independent Nuclear Assurance (INA) Inspector on site to review recent events including proposed changes to INA representation on site, ONR inspection plans and outcomes, fuel route improvements, decommissioning plans, radioactive transport matters, the recent reactor 3 trip and emergent issues on the site. I intend to meet routinely with INA when I am on site.
I was satisfied with the information exchanged during meetings with NGL staff on a range of topics including the recent trip of Reactor 3 and a variety of permissioning activities relating to a number of safety enhancements (eg new Nitrogen plant, kerosene storage tanks, Reactor 3 operational period, Boiler Tube Failure Safety Case, and boiler inspections. I also discussed progress with the third Periodic Safety Review which was on course to be delivered at the end of the year.
The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.
Conclusion of Intervention
There were no findings from this inspection that could significantly undermine nuclear safety. At present, no additional regulatory action is needed over and above the planned interventions of Hinkley Point B power station as set out in the Integrated Intervention Strategy, which will continue as planned.