Testing of an accident consequence assessment model using field data

Homma, Toshimitsu; Matsubara, Takeshi; Tomita, Kenichi*

This paper presents the results obtained from the application of OSCAAR to the Iput dose reconstruction scenario of BIOMASS and also to the Chernobyl I fallout scenario of EMRAS, both organized by International Atomic Energy Agency. The Iput Scenario deals with Cs contamination of the catchment basin and agricultural area in the Bryansk Region of Russia, which was heavily contaminated after the Chernobyl accident. This exercise was used to test the chronic exposure pathway models in OSCAAR with actual measurements and to identify the most important sources of uncertainty with respect to each part of the assessment. The OSCAAR chronic exposure pathway models almost successfully reconstructed the whole 10-year time course of Cs activity concentrations in most requested types of agricultural products and natural foodstuffs. The Plavsk scenario provides an good opportunity to test not only the food chain transfer model of I but also the method of assessing I thyroid burden. OSCAAR showed in general good capabilities for assessing the important I exposure pathways, but also limitations using constant isotopic ratio I /Cs provided by the scenario to estimate I deposition for whole Plavsk district.