Office for Nuclear Regulation

Back-end Fuel Route System Based Inspection (SBI)

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake a planned Licence Condition (LC) System Based Inspection (SBI) on the fuel route at EDF Energy Nuclear Generation Limited’s (NGL) Hunterston B (HNB) Power Station in preparation for end-of-generation (EoG), in line with the inspection programme contained in ONR’s Operational Facilities Division Intervention Strategy for 2020-21.

Interventions Carried Out by ONR

This SBI covered the HNB back-end fuel route (from removal of irradiated nuclear fuel from the reactor through to its preparation for dispatch off-site, as well as managing waste arising). This inspection covered the charge machine, the irradiated fuel dismantling facility, the pond and flask area, the fuel pond (civil structure), the pond water treatment plant and the debris voids. 

This inspection was undertaken by ONR’s HNB site inspector, an end-of-generation project inspector and specialist inspectors from: fuel and core; mechanical engineering, and control & instrumentation.

During this intervention we examined HNB’s compliance with the following nuclear site Licence Conditions (LC), which are all applicable provisions of the Energy Act 2013:

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

Explanation of Judgement if Safety System Not Judged to be Adequate

The Inspection identified several shortfalls in compliance with LC23 across the range of facilities inspected. The technical and environmental specifications did not, in some areas, adequately specify the limits and conditions of operation reflecting those specified in the safety case. There were also shortfalls in the living safety case document which did not accurately reflect the plant configuration.

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

Conclusion of Intervention

The back-end fuel route inspection was wide ranging and involved multiple parallel sessions and a range of ONR specialisms. HNB staff provided access to information and facilities in a timely fashion and supported the smooth running of the inspection. It was considered HNB staff were knowledgeable and general housekeeping standards on site were good.

Overall, we judged that the back-end fuel route systems were in line with the requirements of the safety case and were able to perform their safety functions as required. From the evidence sampled during this inspection, we did identify that, in some areas, the fuel route plant and systems did not meet regulatory expectations relating to LC23 implementation. As a result, ONR will write to the Licensee to seek improvement regarding LC23 compliance.  

In addition, the procedural use and adherence shortfalls, identified under LC24 and LC28, will be followed up as part of regulatory interactions on the licensee’s development of a “Fuel Route Excellence” plan.