Office for Nuclear Regulation

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Hunterston B Planned Intervention

Executive summary

Purpose of intervention

The purpose of this intervention was to undertake Licence Condition (LC) compliance inspections at EDF Energy Nuclear Generation Ltd's (NGL's) Hunterston B power station, in line with the planned inspection programme contained in the Hunterston B Integrated Intervention Strategy (IIS) for 2016/17.

Interventions Carried Out by ONR

This intervention included compliance inspections against the following Licence Conditions:

I also undertook a monthly update meeting with the station Independent Nuclear Assurance (INA) evaluators, met with Safety Representatives and reviewed the station's progress against regulatory issues.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable as no system inspection was undertaken during this intervention.

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

In relation to LC 7, I:

Examined key performance indicators associated with the station's organisational learning (OL) programme (with particular emphasis on the retrospective Corrective Action Programme (CAP) and proactive Self-Assessment). I considered that the organisational learning health scorecard presents a broad picture of proactive and reactive elements of the station OL programme. It was evident that the key performance indicators inform, to a sensible extent, the activities undertaken by the OL organisation.

Examined the effectiveness with which the station trends incidents on the site against its company arrangements. The station has not yet implemented the requirements of company specifications in relation to department trend review boards and cognitive trending analysis to systematically inform twice yearly trending reports. I was nevertheless satisfied that the station does undertake trending analysis but according to a methodology that does not yet align with company arrangements. I have proposed a level 4 regulatory issue through which to monitor progress.

Assessed the adequacy of a recent significant adverse condition investigation and progress against associated corrective actions. This related to the turbine hall crane 8B collision which occurred on 27th February 2016, and site notices for lifting equipment. The incident involved a turbine hall crane colliding with scaffolding leading to minor damage to the scaffolding and roof beams. However, the incident had the potential to lead to risk of serious personal injury.

The investigation was demonstrably undertaken according to the arrangements set out within the company arrangements. Appropriate direct, root and contributory causes were drawn out from the investigation in a systematic manner, supported by SMART corrective actions to prevent reoccurrence of this specific incident.

Notwithstanding, I considered that further assurances from the station are required in relation to the extent of potential for degraded control measures associated with lifting operations across the station. Given previous similar incidents at the station and wider fleet operational experience, further clarity is needed on why the use of degraded control measures was allowed to persist and how this will be avoided in the future.

In light of the shortfalls identified within the station's investigation, I have proposed a Level 3 regulatory issue to monitor the licensee's progress. I have also recommended consideration of this incident against the ONR enforcement management model, the output from which will be conveyed to the station.

In relation to LC 5, I:

Examined records of a recent spent fuel consignment to Sellafield during the past 12 months. I was satisfied that the station demonstrably manages its consignments according to well-defined company arrangements. I confirmed there is consistency in spent fuel consignment information contained in both the Quality Plan and consignment certificates.

Reviewed the arrangements for consigning radioactive wastes off the licensed site, and sampled associated records. I observed appropriate alignment within the consignment certificate and quality plan of inventory and package data.

Was satisfied from discussions with the station that there is an appropriate level of understanding of the distinctions between nuclear matter, radioactive material as defined with the Nuclear Installation Act (1965) and the concept of 'relevant site'. I was further satisfied that there are no consignments of material from the site to non-relevant sites in the UK that would otherwise require consent from ONR under LC 5(1).

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

In relation to LC 7, I considered that an ONR inspection rating of 'Amber' is warranted in light of the failure of previous incidents involving crane collisions at Hunterston to have been adequately investigated, with ineffective promulgation of learning to the organisation. This constitutes in my opinion a significant failure to implement and meet licence compliance arrangements. A lower rating was not necessary on the basis that the station has taken appropriate corrective action in this instance to correct the root cause.

In relation to LC 5, I considered that an ONR inspection rating of 'Green' is justified on the basis that the station is demonstrably compliant with its arrangements made under LC 5 for consignment of nuclear matter to relevant sites in the UK.

There are no findings from this inspection that could significantly undermine nuclear safety.