Identification of optimal countermeasures strategies in agriculture in the long term after the ChNPP accident

The approach for the estimation of the effectiveness of countermeasure strategies in the long term after the Chernobyl accident, based on the classification of farms and rural settlements by site specific factors governing transfer of radionuclides to agricultural products is described. It has been found that application of remediation options on the territory of Russia will be necessary at decreasing scales up to 2050. Settlements and collective farms located on the contaminated territory were divided into 18 categories based on the contamination density of 137Cs and in the first case on annual internal doses and on risk of the overestimation of standards, restricting the use of agricultural products (in the second case). To derive remediation strategies for these categories, 29 settlements and 108 representative farms were studied for which extensive radioecological data were gathered. Eight main remedial actions were considered for each farm (settlement). The effectiveness of each of these actions (applied alone or in combination with each other) in terms of averted doses as well as cost of 1 man-Sv averted was estimated. For each category of the farms the ranking of rehabilitation options and the time periods when their application would be of importance were justified and estimated. Five remediation strategies (including site specific approach justified in the study), different in effectiveness and cost, were compared to provide the information for making decision on rehabilitation of contaminated territories in the long term after the ChNPP accident