Office for Nuclear Regulation

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Heysham 2 Power Station - Licence Condition 22 and 26, and SBI-23 “CO2 Processing and Blowdown” Compliance Inspection

Executive summary

Purpose of intervention

The purpose of this intervention was to undertake Licence Condition (LC) compliance inspections at EDF Nuclear Generation Limited’s (NGL’s) Heysham 2 power station in line with the planned inspection programme contained in the Heysham 2 Integrated Intervention Strategy (IIS) for 2014/15.

Interventions Carried Out by ONR

This intervention included compliance inspections against the following Licence Conditions (LCs):

System Based Inspection, SBI-23 – CO2 Processing and Blowdown, which included:

Explanation of Judgement if Safety System Not Judged to be Adequate

From the inspection, I judge that the CO2 processing and blowdown systems meet the requirements of the safety case and are adequate.

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

The LC22 inspection involved inspection of the arrangements for LC22, which I considered to be robust.  On inspection of the implementation of one of modifications sampled, I judged it to have been inadequately conceived and executed on plant.  It is important to recognise that the affected system had not been returned to service and there was no impact on nuclear safety.  NGL recognised the shortfall and are to formally investigate the events that have led up to this modification through the use of an Apparent Cause Investigation (ACIN).  I have elected to raise an ONR Issue to track progress and for NGL to provide the outcome of their investigation in due course.           

I judge that the implementation of the arrangements for LC22 are below standard based upon the sample undertaken during this inspection and have rated this element of my inspection through the IIS as 4 (below standard).

The LC26 inspection involved consideration of Task Performance Evaluations (TPE) as a means for managers and supervisors to oversee operations personnel as part of their on job training.  I also considered the operational experience and actions arising as a result of an event that occurred that had an impact on TPE.  I judged that the corrective actions should minimise the likelihood of repeat events, however, I will monitor this as part of routine regulatory business.  My plant sample considered the control and supervision elements as part of the inspection on LC22 and given its recent nature, I consider it to be inappropriate to comment specifically on any shortfalls whilst NGL’s internal investigation is on-going.  The ONR issue for LC22 will provide the outcome of the NGL investigation to ONR, at which point I will consider the LC26 elements.

On balance of the evidence presented taking account of the LC22 findings, I judge that the implementation of the arrangements for LC26 are adequate and have rated this element of my inspection through the IIS as 3 (adequate).

The following paragraphs outline the outcome of the SBI performed and detail my judgement in relation to compliance against the applicable licence conditions.

From an LC10 perspective, staff training records and profiles were judged to be in broadly in accordance with the requirements for the roles performed and tasks undertaken with the exception of some minor areas for station to address in accordance with their own arrangements.  I judged the LC10 element of this inspection to be adequate, warranting an associated Integrated Intervention Strategy (IIS) rating of 3 - Adequate.

From an LC23 and LC24 perspective, based on the evidence sampled during this inspection, the implementation of the technical specifications, commentaries, and schedules were judged to have had good alignment with the claims presented within the Heysham 2 Station Safety Report (SSR) for the CO2 processing and blowdown systems. The licensee demonstrated a good knowledge and understanding in the areas of the safety case and how they related to the operating rules and instructions in place for the systems inspected. I judged the LC23 and LC24 element of this inspection to be good, warranting an IIS rating of 2 - Good.

From an LC27 perspective, based on the evidence sampled during this inspection I established that safety mechanisms are not currently specifically defined as such by the site.  However the systems sampled were deemed to be appropriately maintained. Therefore, as far as the existing safety case is concerned, I considered the arrangements for LC27 to have been adequately implemented and warrant an associated IIS rating of 3.

From an LC28 perspective, the licensee demonstrated that there are good processes, procedures and records in place for the examination, inspection, maintenance and testing of nuclear safety significant areas of plant. Several samples were taken and suitable records were produced for each sample, notwithstanding a minor shortfall associated with electronic storage. I judged the LC28 compliance element of this inspection to be adequate, warranting an associated IIS rating of 3 – Adequate.

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

After considering all the evidence examined during the sample inspections undertaken against LCs 10, 23, 24, 27 and 28, I considered that the CO2 processing and blowdown systems met the requirements of the safety case.

One ONR Issue has been raised to address the shortfalls identified during the LC22 inspection.

There are no findings from this inspection that could significantly undermine nuclear safety and no change to the planned interventions and inspections of Heysham 2.