Office for Nuclear Regulation

Hinkley Point B – Inspection ID: 22-015

  • Site: Hinkley Point B
  • IR number: 22-015
  • Date: April 2022
  • LC numbers: N/A

Executive summary

Purpose of Intervention

To provide regulatory confidence in the management of conventional health and safety hazards present at EDF Energy Nuclear Generation Limited (NGL) Hinkley Point B power station (HPB). Specifically, the Control of Major Accident Hazards Regulations 2015. The inspection is part of the annual intervention programme agreed with the facility.

The visit was organised by the Environment Agency and led by the Office for Nuclear Regulation (ONR).  Both organisations working jointly as part of the Competent Authority (CA), to assess adequacy of COMAH regulatory compliance within decommissioning planning and preparation activities. The intervention also provided the opportunity to assess progress with COMAH related corrective actions identified in February 2021.

Interventions Carried Out by ONR

A site inspection was conducted on 12 April 2022 and the key regulatory activities undertaken are summarised below:

  • Review management system arrangements;
  • Review control of hazardous substance inventory and projected substance reduction during decommissioning;
  • Review arrangements for decommissioning planning and preparation, including incorporation of COMAH requirements;
  • Inspect standard of COMAH substance bulk storage at HPB.

Regulatory judgement was based on determining compliance with the Control of Major Accident Hazards (COMAH) Regulations 2015 and Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR).

Explanation of Judgement if Safety System Not Judged to be Adequate


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

CA is content with the outcome of the management system element of the inspection. It is CA opinion that the inventory of hazardous substances is being adequately managed within COMAH lower tier threshold boundaries.  CA verified HPB completion of recommendations raised in 2021. This work was judged to have achieved improvement, particularly in relation to emergency exercises and restarting the COMAH working group. COMAH administrative issues to be followed up relate to:

  • Modification of Major Accident Prevention Policy (MAPP) governance to include the Station Director as the final signatory; and
  • HPB submission of a COMAH regulation 6 notification, due to the change of Station Director as the ‘person in charge of the establishment’.

Planning for the removal of COMAH substances following end of generation and achieving fuel free verification (FFV) was explored. Through post generation plant review work, HPB identified systems and substances no longer required and also those remaining in service until FFV.  Together with the engineering change framework and asset care strategy, it was evident decommissioning planning is progressing through a structured approach.  Whilst this is acknowledged, CA concluded planning regarding prioritisation and resourcing for the removal of COMAH substances requires development. In particular, clarity regarding the safe state / end-of-life condition of COMAH vessels and pipework before transfer to the Nuclear Decommissioning Authority.

CA sampled COMAH substance storage areas during the plant walk down and judged standards observed to be good. CA verified that recommendations highlighted during the previous 2021 intervention, together with the ALARP improvements derived from the Chemical and Downstream Oil Industries Forum (CDOIF) phase 2 risk assessment, have been addressed.

During the inspection CA identified a number of issues judged to be minor, requiring follow up action or provision of additional information. These were discussed in detail with staff and CA is assured HPB understand the matters highlighted. CA will monitor progress through existing communication channels and as part of the next planned site visit.  Site inspection recommendations and information requests are summarised below:

  • Gas turbine fuel oil (GTFO) tank 01 – Removal of waste grinding material accumulated at the external tank base;
  • GTFO tank 01 – Investigate and address through-wall bund penetration opening into adjacent valve room;
  • Vapourising auxiliary boiler fuel tank C – Confirm scheduling of refurbishment work and explore material selection / compatibility as part of vessel corrosion management;
  • Ammonia tank – Confirm scheduling of planned inspection and maintenance work to address tank body corrosion observed;
  • Main stores diesel storage tanks – Provide confirmation of tank replacement plans including proposed timescales;
  • Stores compound –  Arrange the removal of diesel vessels if no longer required.

Conclusion of Intervention

A summary detailing inspection findings, verbal advice and document requests was shared with HPB at the close of the intervention.

An inspection rating of Green, no formal action has been assigned to this intervention.