Nuclear Event - Kozloduy Nuclear Power Plant was evacuated over a detected increase of radiation rare gases, Bulgaria - 28th Apr 2011

Sofia. A higher radiation level has been detected in Bulgaria’s Kozloduy nuclear power plant, Russian Mayak radio station reported.

The staff on duty at the time were exposed to radioactivity of about 0,05 mSv, while the permitted annual dose is 0,5 mSv, which means their health is not at risk, the radio station said.

The incident occurred during planned annual repair works, it added.

On Wednesday the nuclear power plant announced that on April 26 at about 10:45 a.m. local time it detected a higher level of radioactive gas xenon (Xe 133) in the containment reactor during maintenance work in the primary circuit of unit 5.

All people on duty were led out of the facility and measures were taken to normalize the radiation. The radioactivity the staff were exposed to represents up to 10% of the annual dose permitted by safety officers, the facility said.

It added that all its staff on duty were tested for radiation and the results showed they were exposed to radioactivity of about 0,05 mSv, with the permitted level being 0,5 mSv.
The nuclear power plant noted there was no increase in radioactivity outside the containment reactor.

At 6:00 p.m. local time on April 26 the radioactivity in the containment reactor subsided to normal. A committee will analyze the event. The preliminary INES assessment is Level 0, Kozloduy NPP said. Source