Office for Nuclear Regulation

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Magnox Limited Wylfa - Ionising Radiations Regulations 1999 Compliance Inspection and Personal Contamination Event Investigation

Executive summary

Purpose of intervention

This intervention was undertaken to confirm that the level of compliance against Ionising Radiations Regulations 1999 was being achieved by Magnox Limited on the Wylfa Nuclear Licenced Site.  This inspection formed part of Office for Nuclear Regulation (ONR) compliance inspection programme for this site.

Interventions carried out by ONR

Evaluation of IRR99 compliance against the following areas was carried out:

Key findings

The Licensee has effectively reported and investigated personal contamination events during the year and established action plans that will reduce the likelihood and severity of future events.  I noted that these action plans were nearing completion but that progress in some instances had been unacceptably slow.

Arrangements for contamination area exit monitoring, although broadly compliant with IRR99 requirements, could be improved given the number of reported personal contamination events from the reactor control area/inner security barrier.

The close-out of event investigation into a roofing contractor unintentionally receiving exposure although nearing completion was considered to have taken longer than expected.  This event was the subject of an enforcement letter issued to Magnox Limited in August 2014.

Other aspects of IRR99 compliance were, in my judgement, adequate and in some instances to a high standard.

Conclusion of intervention

The intervention did not identify any compliance short-falls that would require immediate enforcement action by ONR and, overall, it is my conclusion that the Licensee is operating to an acceptable level.


A number of findings were identified from this intervention dealing with personal contamination events, follow up to event 9883 dealing with poor ventilation performance and Review location of refectory areas within the R1 zone.  These issues have been recorded on the ONR issues database and will be tracked by Radiation Protection specialist Inspector and nominated site inspector.