Model Establishment for Small Modular Reactor Using MAAP Code and Study on Fission Product Release Characteristics under Severe Accident

Using MAAP code, a plant model was established for the small modular reactor（ACP100）. The behaviors of the model were tested on the steady state condition. It shows good consistency and the errors were 1% between the calculated values and designation values. Based on the model, a simulation was conducted in the case of severe accident, and the development process and source terms released into the environment are analyzed. It can be seen that the cumulative release fraction of nobles is liner with the time and increased with time. Other groups release fraction reach a maximum after a period of time and keep constants after that. The analysis results are provided as the essential input data for quantifying the release of ACP100 and the offsite dose analysis.