Abstract:
AC2 is a program developed by GRS that can simulate fault sequences and accidents in a nuclear power plant. This code can be used to investigate the response of a nuclear power plant to different initial events, allowing researchers and licensing organizations to identify weak spots in the designs and to create accident preventing and/or mitigating strategies. To achieve realistic results AC2 has to be able to model multiple, complex and often inter-acting phenomena. These models are interdisciplinary, covering topics like thermohydrau-lics, chemistry, material sciences and numerics. This presentation will focus on the relevant phenomena that can occur during a severe accident in a nuclear power plant and will dis-cuss the modelling capabilities, limitations of AC2 for these phenomena. The verification and validation process of AC2 will also be briefly demonstrated with the help of experiments and real-life accidents, like the accident in Three-Mile-Island and at the nuclear power plant in Fukushima Daiichi.