Postulated nuclear power plant accident in the Po valley (Italy) and application of the ICRP publication 146 recommendations

Abstract

A large release of radioactive material, consequence of a supposed nuclear power plant (NPP) accident, is simulated in the densely populated and productive area of the Italian Po Valley, using wind speed and atmospheric stability conditions characteristic of the region. The first step of the analysis is the evaluation of the dose received by the public during the plume passage through the HotSpot code. The second step is the calculation of dose in the years following the accident through the RESRAD-ONSITE code, considering soil and food-chain contamination. The third step is the dose reduction obtained with protective actions, mainly iodine prophylaxis and shelter in place. Recommendations contained in the International Commission on Radiological Protection (ICRP) Publication 146 are applied, with the goal of maintaining the public dose below the ICRP recommended Reference Levels. The influence of the height of the release is also analyzed. Without implementing protective measures, the public may be exposed to a dose of up to 2.9 × 102 mSv, although this is confined to a fairly restricted area. However, the dose can be greatly reduced by appropriate and preplanned protective actions. The use of ICRP Reference Levels is of overwhelming importance in guiding protective actions and helping authorities to make balanced decisions.