Hunterston B - Planned Intervention
- Site: Hunterston B
- IR number: 14-123
- Date: August 2014
- LC numbers: 7
Purpose of intervention
The purpose of this intervention was to undertake Licence Condition [LC] compliance inspections at Hunterston B (HNB) power station in line with the planned inspection programme contained in the HNB Integrated Intervention Strategy (IIS).
Interventions Carried Out by ONR
As part of this intervention, we undertook a compliance inspection against licence Condition 7 - Incidents on the site. We also observed elements of the Rapid Trending Review undertaken by a team of Independent Nuclear Assurance [INA] staff from across the EDF fleet as part of early trending for the Reactor 4 statutory outage. During this intervention, other information exchange meetings were undertaken.
Explanation of Judgement if Safety System Not Judged to be Adequate
No safety case informed system based inspection was undertaken during this intervention.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The nominated site inspector and two specialist inspectors observed elements of the Rapid Trending Review [RTR], undertaken by INA to establish and redress developing safety trends associated with the Reactor 4 statutory outage. We also used the process to evaluate compliance against NGL's conventional safety arrangements. Overall observations on the Rapid Trending Review process:
- Station management clearly value the Rapid Trending Review process, who recognise it provides useful leading indicators of performance shortfalls in the early stages of the outage. Station management received INA feedback on a daily basis and demonstrably sought practical advice on resolving shortfalls against expected standards.
- The RTR was adequately represented by INA and operational staff from other Stations.
- The RTR identified four opportunities for improvement [OFI] and no areas for improvement [AFI]. This represents a notable improvement on the RTR undertaken for Reactor 3 in 2012. Each OFI was adequately underpinned by supporting evidence, accompanied by practical advice. The four OFIs identified opportunities to improve on procedural quality and use; laydown processes; protection of operational plant and outage communications.
- Overall, we judged the RTR to have been effective at highlighting emerging trends in safety performance. However, as the week progressed, the level of focus and coordination of RTR staff seemed to diminish leading to repeated oversight of individual work-faces. There is an opportunity for NGL to review its arrangements for undertaking RTRs, and potentially tailor the exercise according to the specific nature of a given outage and previous outage performance as opposed to a 'one size fits all' approach. This will be progressed with the ONR Corporate Inspector.
We inspected the licensee's arrangements under Licence Condition 7 and the implementation of those arrangements for investigation and analysis of operating experience. Key findings:
- The use of a corrective action pre-screening meeting each day is considered to be good practice.
- The event categorisation process and four-levels of investigation rigour are consistent with fleet expectations, with appropriate training for each level in place.
- We attended a Corrective Action Review Board [CARB] and considered the minimum quorum of station management [group heads] to be acceptable. We judged the CARB to have provided an effective framework for open debate and discussion which enabled a more realistic root cause for investigations to be derived.
- Dissemination of OPEX was judged to be effective. A variety of routes are available for dissemination through the learning portal, pre-job briefs and inherent within work packs.
- Station provided evidence of effective cross-fleet trending of Condition Reports and sharing of OPEX.
- We sampled one SACI report [Significant Adverse Condition Investigation] and one MACI [Minor Adverse Condition Investigation] report. The SACI was a high quality investigation, systematic and comprehensive. The use of event and causal factors was evident and effective.
The external hazards specialist inspector examined Station's oversight arrangements for the Western Link Project and sought assurance as to the continued validity of the external hazards safety case. There is continued evidence of effective oversight of the principal contractor activities at the Converter Station site. We sought clarity on Station's arrangements for succession planning for key staff involved in managing the Western Link interactions, and also further evidence of external hazards analysis. This will inform a forthcoming meeting between ONR, EDF and the Principal contractors scheduled for November 2014.
The specialist fault studies inspector secured assurance that regulatory issue 452 has been satisfactorily progressed towards closure, anticipated in September 2014. This is a legacy issue that has endured continued delays since it was initially raised in 2010.
Conclusion of Intervention
We judged the licensee to have implemented the fleet arrangements under Licence Condition 7 in an effective manner with specific areas of good practice demonstrated. An IIS Rating of 2 - 'Good Standard' was awarded.
The licence conditions were inspected against ONR's published guidance requirements (as described in our technical inspection guides).