ASTRAL V2.2: A new version to better assess post-accidental situations

Abstract

Should an important release of radionuclides occur in the environment, one would quickly have to assess radionuclide concentration in media and foodstuff, deduce the potential exposition of concerned populations to the radiations, predict the evolution of the situation and propose different scenarios of managing the contaminated zones. To achieve this, the ASTRAL code was created, which can be used by a relatively large group of people composing crisis centres or making predictive impact studies. The starting point of the assessments is the ground deposit of radionuclides: the atmospheric dispersion phase and the cloud exposure are not taken into account here. The calculations achieved concern time evolution of radionuclide concentration in compartments of the agricultural and forest food chain as well as assessment of doses due to external and internal exposure. These values are compared to regulation limits and/or intervention levels. Different simulations of contaminated zones management can be led by applying counter-measures, dispositions meant to reduce the accident's impact on environment and populations. The seventy radionuclides taken into account in the present version are some of those met in case of accidents or during the exploitation of a Pressurized Water Reactor (PWR). They relate to 37 elements: Ag, Am, Ba, Br, Cd, Ce, Cl, Cm, Co, Cr, Cs, Eu, Fe, I, Ir, La, Mn, Mo, Nb, Nd, Ni, Np, Pm, Pr, Pu, Rb, Rh, Ru, Sb, Sm, Sn, Sr, Tc, Te, Y, Zn, Zr. On a temporal point of view, the predictions extend to 3 years after the deposition. The internet technology chosen for this version offers important advantages: the spreading and maintenance of the tool are very easy, the code may be installed on a portable computer, the access to results is much quicker, the interface is very user friendly, so that no training is needed to perform calculations. As for any radioecological tool, a large number of parameters intervene in the calculations. All parameters can be modified, even though different user profiles grant different rights in handling them.