Office for Nuclear Regulation

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System Based Inspection of the Additional Fuel Storage Facility (AFSF) - Review of ONR Issues

Executive summary

Purpose of intervention

The purpose of this intervention was to undertake a system based inspection at EDF Nuclear Generation Limited’s (NGL’s) Heysham 1 power station in line with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy (IIS) for 2014/15.

The inspection was undertaken by the nominated ONR Site Inspector and a Technical Specialist and concentrated on the Additional Fuel Storage Facility (AFSF). The aim of the inspection was to confirm that the AFSF, with its’ associated operating instructions and maintenance schedule, is able to meet the safety case functional requirements.

The nominated site inspector also carried out a quarterly review of the progress of ONR issues raised on the station.

Interventions Carried Out by ONR

The system based inspection of the AFSF was conducted against compliance with the following licence conditions:

The inspections were based on sampling the implementation of the arrangements in place against each licence condition. Pre- and post- inspection meetings with the site personnel were held and the main findings were communicated.

Explanation of Judgement if Safety System Not Judged to be Adequate

I judged that the AFSF adequately meets the requirements of the safety case.

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

The training records of a number of fuel route staff were sampled against their role profile and all were found to have completed the essential training to be considered Suitably Qualified and Experienced Persons (SQEP) to carry out their roles. Compliance against LC10 was therefore judged to be adequate with an IIS rating of 3.

It was noted that an Interim Justification for Continued Operation (IJCO) has been produced in advance of the production, by the end of 2016, of a long term safety case for the continued operation of the AFSF, reflecting the current operating regime and plant reliability.  Unfortunately this document has not yet completed internal due process despite being in production for over 9 months.  The IJCO has recommended some stricter limits and conditions for the restoration of cooling water and therefore an action has been placed on the station to complete this process as soon as reasonably practicable.  Notwithstanding this I am satisfied that there is sufficient margin in the safety case not to warrant any immediate action.  I have raised an ONR issue to address this shortfall with appropriate timescales for completion. This issue will be closely monitored and further regulatory intervention will be undertaken, if required.

A further ONR Issue raised requiring station to review the limits and condition of operation for the pressure relief valves and demonstrate safety case and pressure systems safety regulations compliance.  In light of these two ONR Issues compliance with LC23 was deemed below standard with an IIS rating of 4.

I considered that the existing arrangements and operating instructions that were in place for the AFSF are adequate and have therefore rated this intervention against LC24 as adequate with an IIS rating of 3.

The station has identified all the critical components for the AFSF and they are routinely checked and suitable and sufficient maintenance is undertaken.  Consequently I judged that compliance with LC27 and LC28 was adequate with IIS ratings of 3 against both these licence conditions. 

The AFSF is designed to minimise the leakage and escape of radioactive material. In addition regular shift walk downs are carried out to check for leaks. Currently there is a minor water leak from one Essential Cooling Water (ECW) pump which is being actively managed and there is no radioactivity associated with this leak.  I therefore judged compliance with LC34 to be adequate with an IIS rating of 3.

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

From the evidence gathered during this intervention, I do not consider there to be any matters that have the potential to impact significantly on nuclear safety.   Notwithstanding this, two issues have been raised on the station where compliance was deemed to below the expected standard.  These issues will be pursued as part of normal business by the site inspector.  At present, no additional regulatory action is needed over and above the planned interventions of Heysham 1 power station as set out in the Integrated Intervention Strategy, which will continue as planned.