Assessment of radiological safety and emergency response of VVER-1200 type reactor

Abstract

We studied the radiological safety and emergency response of the VVER-1200 type nuclear power plant using the RASCAL 4.3 and HOTSPOT 3.1.2 codes for INES levels 5, 6, and 7 reactor accidents due to SBO concomitant with LOCA for both dry and rainy seasons. The simulation was performed using Gaussian Plume Model and Lagrangian Gaussian Plume Model, respectively. The meteorological data for dry and rainy seasons were considered for the RNPP site of Bangladesh. The amount of total radioactivities of radiological equivalence to I-131 that released to the atmosphere for INES levels 5, 6, and 7 nuclear reactor accidents were 4011.6 TBq, 25,110 TBq, and 129,650 TBq, respectively. Radiological doses such as TEDE, TED, Thyroid CDE, Inhalation CEDE were evaluated for 40 km radial distance from the reactor site. The total effective dose for both RASCAL and HOTSPOT code predicts the higher dose value during the rainy season compared to the dry season. In the rainy seasons, TEDE and TED were very high about several ten times of permissible limit within 16 km radial distance. Therefore, immediate radiological protective measures are required to be implemented based on the emergency response plan of the local regulatory authority.