Office for Nuclear Regulation

Intervention to sample the control of Internal Hazards during a planned outage

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake an Internal Hazards inspection at EDF Energy Nuclear Generation Limited (NGL) Hartlepool Power Station (HRA) during the Reactor 2 (R2) periodic shutdown, sampling aspects of the management of internal hazards during the outage. The intervention was carried out in line with the inspection programme contained in the HRA Integrated Intervention Strategy (IIS) by two ONR internal hazard specialist inspectors.

Interventions Carried Out by ONR

We undertook an inspection and assessment of the implementation of internal hazards arrangements for the outage at Hartlepool. This was achieved by reviewing the arrangements in place for identifying and minimising any nuclear safety impacts that may arise from internal hazards during outage activities.

The inspection targeted and sampled some of the key internal hazards that may arise during outage activities (i.e. fire, dropped loads and impacts). We also sampled the training provided to contractors to ensure internal hazards are effectively managed during the outage.

At the request of the ONR site inspector, we also inspected modifications made to the cable fire segregation arrangements in the reactor basement.

Explanation of Judgement if Safety System Not Judged to be Adequate


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

Based on the discussions, explanations and the sample inspected, we were satisfied that there had been improvements in hazard management in recent outages and no significant shortfalls were identified with the internal hazards management arrangements in relation to the planned outage activities.

The additional cable fire segregation has been achieved by applying a proprietary intumescent coating to the cable races. This appeared to be adequately carried out and it appears that a sufficient length of cables has been protected. From the manufacturer’s information it is likely that the particular application of coating will have a service life in excess of that for the station. However ONR would like to use this example to learn more about the future life of the coating, and any post-installation testing and reapplication or replacement. This will be taken forward for discussions both with station and with EDF’s central technical organisation.

Conclusion of Intervention

The intervention has not been rated, but from the evidence gathered during this intervention, there were no significant issues identified with the internal hazards arrangements. No shortfalls were raised against relevant Licence Conditions and no changes to the future IIS plan are necessary as a result of this intervention.