EXTENDED MONODISPERSE AEROSOL MODELING FOR FUSION POWER-PLANT CONTAINMENTS

It is found for conditions relative to fusion safety studies that ther e is a range of initial aerosol masses (up to approximate to 1000 kg) within which the aerosol particle growth dynamics are dominated by Bro wnian agglomeration. Above this range, the dominant growth mechanism i s gravitational agglomeration. Previously, monodisperse aerosol modell ing has been reported (W.E. Han, 19th Symposium on Fusion Teechnology, Lisbon, Portugal, 15-20 September, 1996) which enables the accurate p rediction of aerosol behaviour up to initial masses of approximate to 1000 kg. Here monodisperse modelling is extended to deal with initial aerosol masses above 1000 kg, enabling the prediction of aerosol trans port and the release to the environment in the gravitationally dominat ed agglomeration regime for hypothetical accidents involving mobilised radionuclides. It is shown that increasing the initial aerosol mass i n the Brownian dominated agglomeration regime results in increased rel ease to the environment. However, increases in initial mass in the gra vitationally dominated regime soon lead to a maximum in release to the environment; as a result, further increases in initial mass produce s maller releases to the environment. (C) 1998 Elsevier Science S.A. All rights reserved.