Executive summary
Date(s) of inspection:
- February 2025
Aim of inspection
The focus of this intervention is on restriction of exposure, contingency arrangements, control of designated areas and radioactive source management associated with industrial radiography and the use of gamma radiography sources, especially the use of Co60 on the primary circuit welds.
As the volume of open site radiography increases the control of the designated areas can become more challenging.
In addition, with the increased number of radiography worksites and exposures, the potential for the enactment of the contingency plans increase.
The intervention is to gain continued confidence that arrangements are in place to restrict exposure and access into designated areas of those not involved in radiography operations, and there are suitable arrangements for the storage and accountancy of the radiography sources.
The intervention will also consider any radiography related event investigations undertaken and how the recommendations have been implemented.
The intervention will also review observation and regulatory advice given during the previous IRR17 intervention undertaken in August 2024.
Industrial radiography represents a significant risk to health and safety if not appropriately managed.
Recognising that NNB GenCo do not undertake industrial radiography themselves, and that ONR has assessed and issued a Ionisation Radiations Regulations 2017 (IRR17) Consent for the management of industrial radiography for NNB GenCo, the intervention will primarily look at the arrangements of the industrial radiography contractors working on the site.
Keys areas to be examined:
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Radiation risk assessments and the identification of fault scenarios and potential dose exposures, including recovery dose estimates.
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Dose monitoring and trending.
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Contingency plans and how the training associated is undertaken and monitored.
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Control of the radiography designated area – monitoring, signage and restriction of access.
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Observation of industrial radiography set-up and area searching being undertaken.
The intervention will be undertaken in relation to the requirements of the Ionisation Radiations Regulations 2017.
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 NNB GenCo and key contractors, examine appropriate documents, and undertake a site visit to gain continued confidence ahead of primary circuit radiography activities utilising Ir192 and Co60 gamma radiography sources, and that arrangements are in place to restrict exposure to as low as reasonably practicable (ALARP).
Additionally, contingency arrangements, control of designated areas, and radioactive source management associated the primary circuit radiography was also reviewed.
There was time to review a number of points raised during a previous radiography focused inspection in August 2024 and how these had been addressed.
NNB GenCo do not undertake industrial radiography themselves, with the inspection focussed on the arrangements of the industrial radiography contractors undertaking this work.
I was content that the industrial radiography contractors have suitable arrangements in place to restrict exposure of both those undertaking, and those not involved in the primary circuit radiography operations, they have suitable contingency arrangements in place, and these have been, and will be further exercised before the primary circuit radiography is undertaken.
A number of observations relating to the risk assessment and method statement for the use of Co60 were raised, and the requirement to ensure there is a suitable an sufficient fire risk assessment for the proposed Co60 radiography source store were made during the intervention. A number of actions were agreed at the time, and these will be followed up via normal regulatory interactions.
I did state that depending on my subsequent review of documents in relation to fire risk assessments submitted to me during the inspection, I reserved the right to raise a level 4 regulatory issue to ensure that this was completed ahead of the use of the radioactive source stores within HR1.
It was recognised there was still work to be done ahead of the use of Co60 for primary circuit gamma radiography.
Conclusion
I judged that, on the basis of evidence sampled at the time of this inspection, compliance with IRR17 demonstrated, and an inspection rating of Green (no formal action) is appropriate.