Radioecological assessments of the Iodine working group of IAEA's EMRAS programme: Presentation of input data and analysis of results of the prague scenario

Abstract

Abstract. In 2003 IAEA launched the EMRAS Programme aiming at evaluating the predictive power of radiological models. The programme continued work of previous international radioecological modelling programmes and comprised several working groups focusing on different aspects of environmental modelling. The Iodine Working Group reassessed the impact of the release of 131 I during the Chernobyl accident with the aim of comparing model predictions with environmental data and inter-comparing the model predictions. Measurement data and detailed geographic and demographic descriptions were available for three regions: Plavsk, Warsaw and Prague. As for the Prague Scenario, milk supply regions of three big dairies were chosen for the model validation. Apart from geographic, demographic and agricultural descriptions (e.g. gathering regions of the dairies, feeding regime), the modellers were provided with information on the weather conditions and measurement data of iodine contamination. The most important peculiarities of Prague Scenario were keeping milk cattle in sheds and a special feeding regime during May 1986. The modellers were asked to assess the 131 I content in the thyroid of the local population and the resulting dose. The assessments were compared with measurement data. The results of these model calculations and their comparison with experimental data are presented.

Radioecological modeling of the 131I activity dynamics in different types of grass vegetation in the Chernobyl accident year

“…The model's input data consists of the following set of dynamic parameters: specific volumetric activities and occurrence forms of radionuclides in the atmosphere, daily average air temperatures from the beginning of the vegetation period, rainfall in the period of and after the fallout deposition, and crop yields in the accident year. This dataset, along with the data on the 137 Cs fallout densities in residential areas (RA), is presented, to a greater or smaller extent, in the EMRAS project scenarios (Krajewski et al 2008;Bartuskova et al 2009; IAEA-TECDOC-1678 2012).…”

“…The materials of the Prague and Warsaw scenarios under the IAEA's EMRAS project (Krajewski et al 2008;Bartuskova et al 2009;Zvonova et al 2010;IAEA-TECDOC-16782012 were used in (Vlasov et al 2019) to generate such databases. The key conclusion made in (Vlasov et al 2019) was that the use of mutually consistent data on the rainfall in the major fallout period, the specific volumetric activities of 137 Cs in the atmosphere, and its fallout densities was expected to lead to a major decrease in the uncertainties involved in the 137 Cs and 131 I transport in the food chain and, therefore, to more accurately reconstructed internal exposure doses to the populationresided in the contaminated areas.…”