Screening releases outside for accidents

For quantification of impacts due to accidental release of radionuclides from facility to the atmosphere, SAFRAN uses release screening values. The SAFRAN database included release screening values are defined as the release that would lead to 0.1 mSv annual effective dose to members of the population under conservative exposure conditions.

The considered exposure conditions assumes:

• Release occurs from the building at the effective height of 10 m;
• Critical group member lives in average at a distance of 30 m from the source in the downwind direction. In terms of atmospheric dispersion, this exposure point is inside the wake zone of the building from which the radioactive emission occurs.

Calculated annual dose includes:

• External exposure by radiation from the radioactive air plume (air submersion);
• External exposure by radiation from contaminated ground (ground radiation);
• Internal exposure by radionuclides which are inhaled with the air (inhalation);
• Internal exposure as result of consumption of radionuclide contaminated foodstuffs (ingestion).