Level 2 incident in the EDF nuclear power plant at Le Blayais (Gironde département): Irradiation of a worker during the scheduled outage of reactor 4

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On 21^st August 2015, ASN was informed by EDF of the accidental exposure of a worker from an EDF contractor to a dose of ionising radiation exceeding the regulation limit.

On 18^th August, during the check carried out prior to exiting the limited access area, contamination was detected on the worker’s chin. He had been carrying out maintenance work in preparation for the hydrotesting of an exchanger on the chemical and volume control system in the reactor 4 safeguard auxiliaries building in the Le Blayais NPP.

The worker was then treated by the site’s risk prevention department, which carried out a decontamination procedure, during the course of which the radioactive particle which caused the contamination was located and immediately removed. The occupational physician then evaluated the whole-body dose received and the dose on the skin of the chin.

For workers liable to be exposed to ionising radiation during their professional activities, the annual regulation dose limits are, for twelve consecutive months, 20 millisieverts for the whole body and 500 millisieverts for a 1 cm² area of skin.

EDF’s evaluation of the dose received by the worker’s chin exceeded the regulation limit for the skin. The whole-body dose received by the worker is well below the annual regulation limit.

ASN carried out an inspection on the site on 24^th August 2015. The inspectors checked that EDF and the contractor had taken all necessary steps to ensure adequate management of the incident and to analyse its causes.

Owing to the fact that the annual regulation dose limit for the skin was exceeded, EDF submitted a proposal to ASN for a level 2 rating of this event on the international nuclear events scale (INES), which comprises 8 levels, from 0 to 7. ASN confirms the level 2 rating of this incident.