Office for Nuclear Regulation

Control of Major Accident  Hazards (COMAH) inspection

Executive summary

Purpose of Intervention

The purpose of this intervention was to provide regulatory confidence in the management of conventional health and safety (CHS) hazards, specifically relating to Control of Major Accident Hazards (COMAH) Regulations present at EDF Energy Nuclear Generation Limited’s (NGL) Heysham 1&2 power stations. This is in line with the annual COMAH intervention programme agreed with the facility.

This was an inspection to verify progress with the implementation of environmental improvements identified as part of the Environmental Risk Assessment completed separately for both Heysham 1 and Heysham 2 sites. This visit provided a site familiarisation opportunity to allow effective prioritisation and targeting of future intervention strategies by the new COMAH inspectors.

I was accompanied and supported by the Heysham 1 nominated site inspector during this inspection that was at the station as part of his routine station planned visit.

Interventions Carried Out by ONR

The key regulatory activities undertaken during the one day inspection were based around:

Explanation of Judgement if Safety System Not Judged to be Adequate


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

Environmental Risk Assessment Actions

Heysham 1 – The report for Heysham 1 was received in September 2018 and identified four possible options for further consideration. Three of these options have been taken forward for implementation. Of these the work required for two options should be completed within the next few days. Work on the third option is progressing and should be completed by the end of December 2019 at the latest

Heysham 2 – The report from Heysham 2 was received in August 2019 and identified six possible options. With the intention that at least one of these options will be implemented in 2020. Work has commenced on a further option and is expected to be completed in the near future.

Bulk Storage Areas

Heysham 1 – Inspection identified empty redundant tanks, which are to be removed from site; minor corrosion to other tanks, which require follow up.

Heysham 2 – Inspection identified issue with sump pump in derv bund; disused hydrazine tank was found to be full. This was later tested and found to be water, tank subsequently emptied and isolated.

Conclusion of Intervention

A small number of areas of concern where improvements are required in addition to examples of good standards were seen during the visit. These were summarised during feedback provided at the conclusion of the visit, as were the visit outcomes/actions required by EDF. The Environmental Safety Group Head, Environmental Compliance Coordinator and Industrial Safety were present at the feedback session.

Despite the minor issues raised, the overall impression gained from the inspection in relation to COMAH was a satisfactory one.

These shortcomings aside, health and safety management standards met legal requirements. Therefore, an inspection rating of ‘green – acceptable’ should be applied to all parts of the intervention.