Abstract
Severe accidents attract the attention from the nuclear safety analysis researchers after the occurrence of Three Mile Island and Chernoby severe accidents. Safety analysis plays an important role in investigating the severe accidents since they can not be experimentally studied. With the advantage of fast simulation, MAAP code is usually adopted to simulate the sequences of severe accidents. The majority of this paper is to investigate the phenomena related to the severe accidents occurred in the Lung-men Nuclear Power Plant (LMNPP) through MAAP 5 code. The key phenomena include core uncovery, fuel meltdown, debris transfer, vessel failure, and hydrogen production, etc. According to the Final Safety Analysis Report (FSAR), the present simulation cases can be divided as : (1)Loss of All core Cooling with Failure at Low Pressure(LCLP) (2)Loss of All core Cooling with Failure at High Pressure(LCHP) (3)Station Blackout with RCIC(SBRC) (4)Loss Of Containment Heat Removal(LHRC) (5)Large LOCA with Failure of All Core Cooling(LBLC) (6)Concurrent Loss of All Core Cooling and ATWS with Vessel failure at Low Pressure (NSCL) (7)Concurrent Loss of All Core Cooling and ATWS with Vessel failure at Hgh Pressure (NSCH) (8)Concurrent Station Blackout with ATWS(NSRC) In addition, this paper also investigates the effects of RCIC injection time on the consequences of severe accident in the LMNPP under the similar conditions to the Fukushima NPP.