Determination of exclusion area and low population zone for the Bushehr power plant

For the purpose of limiting the radiological hazards in the event of an accident that could lead to the escape of radioactivity to the environment, all of the radiation protection agencies including ICRP recommend two restricted areas in the vicinity of reactors, Exclusion Zone Boundary (EZB) and Low Population Zone (LPZ). Requirement for determination of EZB and LPZ is that a person who remained on the boundary of either zone during two hours and the thirty days respectively would not receive a calculated whole-body dose exceeding 25 rem or thyroid dose exceeding 300 rem. In Bushehr Power Plant, during the large loss of Coolant Accident (LOCA) which is the safety analysis report design basis accident, the activity from coolant, gap and fuel pellets may be released first into the containment and then possibly leak into the environment. The released activity to the environment has been used as a source of radioactivity to calculate EZB and LPZ distances. In this paper first by solving three sets of differential equations radioactivity in the fuel rod, coolant and containment is estimated. Finally the radius of 1 Km for Exclusion Zone and 12 Kms for Low Population Zone have been proposed. (Author)