CRITERIA FOR THE PROTECTING OF POPULATION AFTER RADIATION ACCIDENT: USE OF RADIATION RISK FOR ANALYSIS AND OPTIMAL DECISIONS MAKING TO LIMIT THE CONSUMPTION OF FOOD CONTAMINATED BY TECHNOGENIC RADIONUCLIDES

The purpose of this paper is to assess the compliance of criterion A, adopted in NRB-99/2009 as emergency level of dose intervention, to permissible values of specific activity of 137 Cs, 90 Sr and 131 I in food products in the first year after the accident. Assessments are made on the basis of comparison of the conservativeness coefficients by dose and the magnitude of the risk. The results of the evaluation showed that estimates of the doses and risks for 137 Cs, 90 Sr, calculated on the basis of weighting by the number of age groups, are equally conservative. For 131 I, the conservative factors for dose and risk vary significantly, which indicates that it is not appropriate to use an effective dose to optimization of radiation protection for the given radionuclide. The ratios of the risk-weighted average weighted by the number of individual age groups to the weighted average effective dose values for 137 Cs and 90 Sr are close to the nominal risk of death from malignant neoplasms for the population of 5 × 10 -5 , which confirms that nominal risk factors can only be used for the general population. Two variants of the criteria for optimization of the radiation protection of the population are proposed: 1) by the value of the average weighted by the number of individual age groups, the value of the effective dose, or 2) the value of the average weighted by the number of individual age groups of risk. It is shown that to optimize the protection of individual age groups, the more preferable criterion is the risk value calculated for a given age group, since the maximum effective dose of some age group does not always correspond to the maximum risk.