Urban Working Groups in the IAEA's model testing programmes; Overview from the MODARIA I and MODARIA II programmes

Thiessen, K. M.*; Boznar, M. Z.*; Charnock, T. W.*; Chouhan, S. L.*; Federspiel, L.; Grai, B.*; Grsic, Z.*; Helebrant, J.*; Hettrich, S.*; Hulka, J.*; Hwang, W. T.*; Kamboj, S.*; Korolevych, V.*; Kua, P.*; Lee, J.*; Mancini, F.*; Mlakar, P.*; Patryl, L.*; Pattantys-braham, M.*; Reisin, T.*; Sdouz, G.*; Silva, K.*; 高原 省五  ; Tay, B. K.*; Walter, H.*; Yankovich, T.*; Yu, C.*

Thiessen, K. M.*; Boznar, M. Z.*; Charnock, T. W.*; Chouhan, S. L.*; Federspiel, L.; Grai, B.*; Grsic, Z.*; Helebrant, J.*; Hettrich, S.*; Hulka, J.*; Hwang, W. T.*; Kamboj, S.*; Korolevych, V.*; Kua, P.*; Lee, J.*; Mancini, F.*; Mlakar, P.*; Patryl, L.*; Pattantys-braham, M.*; Reisin, T.*; Sdouz, G.*; Silva, K.*; Takahara, Shogo; Tay, B. K.*; Walter, H.*; Yankovich, T.*; Yu, C.*

The IAEA's model testing programmes (1988-2019) have included a series of Working Groups concerned with modelling radioactive contamination in urban environments. This paper describes the exercises conducted during the MODARIA I (2012-2015) and MODARIA II (2016-2019) programmes. These exercises have included short-range and mid-range atmospheric dispersion exercises based on data from field tests or tracer studies, hypothetical urban dispersion exercises, and an exercise based on data collected after the Fukushima accident. Improvement of model capabilities will lead to improvements in assessing various contamination scenarios (real or hypothetical), and in turn, to improved decision-making and communication with the public following a nuclear or radiological emergency.