Abstract
In this research, the RELAP5/SNAP model of Lungmen ABWR nuclear power plant (NPP) was established for the study of URG (ultimate response guideline). The depressurization/low pressure water injection of the reactor and the venting of containment are the main actions of URG. This research focuses to assess the URG utility of Lunemgn NPP under Fukushima-like conditions. There are two steps in this study. The first step is the establishment of Lungmen NPP RELAP5/SNAP model using the system and operating data, startup tests reports and FSAR of Lungmen NPP. The second step is the URG simulation and analysis under Fukushima-like conditions by using the above RELAP5/SNAP model. In this step, the no URG case was also performed to evaluate the URG effectiveness of Lungmen NPP. According to RELAP5 results, the URG can keep the peak cladding temperature (PCT) below the failure criteria 1088.7 K under Fukushima-like conditions. It indicates that Lungmen NPP can be controlled in a safe situation.