The ultimate response guideline simulation and analysis by using TRACE/FRAPTAN for Chinshan Nuclear Power Plant

TRACE and FRAPTRAN models of Chinshan BWR/4 nuclear power plant (NPP) were established for the ultimate response guideline (URG) simulation and analysis. The depressurization of the reactor, low pressure water injection of the reactor, and containment venting are the main actions of URG. This research focuses to evaluate the URG utility under Fukushima-like conditions. This study consists of three steps. The first step is the establishment of TRACE and FRAPTRAN models. The second step is the URG simulation and analysis under Fukushima-like conditions by using TRACE model. In this step, the no URG case was also performed in order to evaluate the URG effectiveness. Additionally, the sensitivity study of URG and the required raw water injection were performed. The final step is the fuel rod analysis of FRAPTRAN for the above cases. According to TRACE results, the URG can keep the peak cladding temperature (PCT) below the criteria 1088.7 K under Fukushima-like conditions. It indicates that Chinshan NPP can be controlled in a safe situation. If Chinshan NPP does not perform the URG under Fukushima-like conditions, the water level may drop lower than TAF (top of active fuel) which may result in the generation of the safety issue about the fuel rods. FRAPTRAN results depicted that zirconium-water reaction generated in no low pressure water injection cases. It may cause a safety issue in fuel rods. And, the actions of URG affected the performance of fuel rods according to FRAPTRAN results. (authors)