 INES 1 |
Radioactive contamination at the Unit N3 |
On April 24, 1996 at Unit N3 a ventilation filters replacement was made. the filters were installed at Unit N3 but designed for purification of air from a so-called "Sarcophagus" or "Shelter" (Unit N4, destroyed in result of 1986 Chernobyl accident). After completion of the work, a contamination of floor in a few rooms, exceeding prescribed level, was detected. Contamination of the area was caused by a violation of procedures while replaced filters had been removed.
There was no release of radioactive materials to the environment, nor radiation exposure to any personnel.
On April 25, after decontamination of rooms had been completed, the contamination level was decreased to a prescribed level.
Justification of rating:
Off-site impact criterion is not appropriate for the vent rating. A contamination level is too small to apply on-site impact criterion. the event is rated under the degradation of defence in depth criterion with level 1, taking into consideration an additional factor - violation of procedures.
Event date: Wed, 24-04-1996
