Development of Aerosol Behavior Analysis Module for GAMMA+

Fission product (FP) generated by nuclear fission in VHTR can be released from small amount of inherently defective fuel during normal operation or by fuel damage under accident condition. Fission product released from various plant conditions is also mainly in a form of aerosol, which means suspensions of small solid or liquid particles in gases, except some gaseous radionuclide. Despite VHTR's improved safety features, considering potential risk such as possibility of fuel damage caused by graphite oxidation during air ingress accident, FP aerosol behavior needs to be understood better and modeled with considerable reliance in a safety analysis of VHTR. Completing that work properly, however, is not that simple because analysis of aerosol behavior includes various uncertainties resulting from many state variables, complex sub-models, and multiple spatial dimensions. This paper deals with the application of the MAEROS model, which has been widely used for aerosol behavior analysis, as an independent module in GAMMA+, and verifies the validity of calculation results with simplified analytic solution as well as experimental data produced by Gwangju Institute of Science and Technology (GIST). Through this process, it could be found that how effectively the MAEROS model in GAMMA+ simulates various phenomena regarding aerosol behaviors, and what the limitation of this analysis tool is