R7 facility : dysfunction of a ventilation circuit's gate

Incident report

July 04, 2001

On Friday the 18th of May 2001, following a ventilation problem in a facility of the plant, an increase of activity released by a stack has been observed, which represent less than 2 / 10 000 of annual limits of releases.

The monitoring operations performed in the environment of the plant have permitted to find a maximum of 1Bq/g (Becquerel per gramme)in a point of grass.

The impact of this event for a human body who possibly could have been exposed during this release is around 1 microsievert per year.
For memory, the impact of natural radioactivity is localy 2700 microsievert per year.

It has been suggested to the Safety Authority to class this event at Level 0 of the International Nuclear Event Scale (INES). This event has been reclassified at Level 1of the International Nuclear Event Scale (INES) on July the 04th by the Safety Authority.