Executive summary
Date(s) of inspection:
December 2023
Aim of inspection
The aim of the inspection was to ensure compliance with the Ionisation Radiation Regulations 2017.
The focus was related to NNB Generation Company (HPC) Ltd's (NNB GenCo) recent submission to ONR of its safety assessment in support of its Ionisation Radiations Regulations 2017 (IRR17) Regulation 7 Consent for industrial radiography, specifically implementation of the arrangements. Industrial radiography represents a significant risk to health and safety if not appropriately managed.
The objectives of the inspection were:
- to gain confidence NNB GenCo has suitable arrangements in place to restrict access to radiologically designated controlled areas, and to restrict exposure of those not involved in radiography operations; and
- to consider the adequacy of the safety assessment submission.
Subject(s) of inspection
- IRR17 - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
The inspection provided suitable time to discuss arrangements with key staff, examine appropriate documents, and undertake a site visit to understand the complexities and challenges when undertaking open-site and enclosure radiography during the current phase of the construction works.
I was content that NNB GenCo has suitable procedures and processes in place for all radiography contractors to follow to ensure compliance with IRR17.
NNB GenCo currently has appropriate resources to monitor industrial radiography operations on the site to ensure arrangements are compliant and doses remain as low as reasonably practicable (ALARP), although it is recognised a sampling regime may be adopted once mechanical, electrical, heating and air conditioning (MEH) bulk radiography is fully underway.
The evidence provided by NNB GenCo addressed the requirements of IRR17 Regulation 7 Consent safety assessment for industrial radiography.
I sought reassurance from NNB GenCo that:
- it could demonstrate parity between contractor expectations and NNB GenCo expectations relating to the provision of assistance to contractors in the event of a contingency plan enactment;
- it was content with the frequency of contingency plan rehearsals of its contractors, specifically relating to source recovery;
- robust justification was produced for open site use of gamma source radiography in the x-ray radiography bunkers, accepting that the radiography using this approach did not go ahead; and
- suitable arrangements are in place to support the monitoring and oversight of MEH bulk radiography, including radiography source management.
I requested a copy of a revised fire risk assessment to justify the use of bolts to hold closed exit doors in the liner bunker 5.
I stressed the importance to NNB GenCo that many of the current arrangements, although adequate, were administrative in nature and would need to be reviewed and resourced appropriately to maintain their adequacy to support MEH installation works.
Conclusion
I judged that, on the basis of evidence sampled at the time of this inspection, compliance with IRR17 was demonstrated and an inspection rating of Green (no formal action) is appropriate.