Assessment of doses in contaminated urban areas: modelling exercise based on Fukushima data

Abstract

State-of-the-art dose assessment models were applied to estimate doses to the population in urban areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Assessment results were compared among five models, and comparisons of model predictions with actual measurements were also made. Assessments were performed using both probabilistic and deterministic approaches. Predicted dose distributions for indoor and outdoor workers from a probabilistic approach were in good agreement with the actual measurements. In addition, when the models were applied to assess the doses to the representative person, based on a concept recommended by the International Commission on Radiological Protection and in the International Atomic Energy Agency Safety Standards, it was evident that doses to the representative person obtained with a deterministic approach were always higher than those obtained with a probabilistic approach using the same model.

Urban working groups in the IAEA’s model testing programmes: overview from the MODARIA I and MODARIA II programmes

“…During the MODARIA II programme (Takahara et al 2022), modelling endpoints included comparison of deterministic and probabilistic calculations of external doses to the representative person, comparison of predicted doses with observed distributions of doses to actual population groups (indoor workers, outdoor workers, pensioners), and some initial investigation of the predicted effectiveness of remedial actions in terms of reduction of predicted doses to the representative persons. Continuation of this exercise is planned for the Harmonized Methods for Radiological Environmental Impact Assessment programme, which will follow MODARIA II.…”

“…The MODARIA II programme (2016-2019) included a Working Group entitled 'Assessment of Exposures and Countermeasures in Urban Environments' . The activities of this Working Group included six modelling exercises (Takahara et al 2022. The short-range atmospheric dispersion exercises of EMRAS II and MODARIA I, based on data from field tests, were continued during MODARIA II, using data from a field test at a different location than the earlier tests.…”