A Study on Anticipated Transient Without Scram Accident Analysis for Chin-Shan and Lung-Men Nuclear Power Stations
| Autor: | Ya-Chuan Huang, 黃雅娟 |
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| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 No matter how the nuclear reactors are designed for safety, the accident still occur. After the Three Mile Island accident, the nuclear industry performed a variety of small- and large-scale severe accident research to understand the severe accident phenomena and to develop severe accident analysis code for improving the severe accident sequences prediction capability. Under the severe accident conditions, it is necessary to have realistic emergency operating procedures (EOPs) to pursue an overall evaluation of the conditions for the operators and technical staff to bring the plant to a safe-stable state. Based on the established parameter files of the Chin-Shan and Lung-Men Nuclear Power Stations, the Modular Accident Analysis Program version 4.0.4 (MAAP 4.0.4) was used for steady state evaluation. Performing the steady-state simulations assure the appropriateness of the parameter files used for the MAAP calculations. The purpose of this study is to evaluate the postulated anticipated transient without scram (ATWS) severe accident scenarios for the Chin-Shan and Lung-Men Nuclear Power Stations. In this study, the behaviors of reactor core and containment, and release of fission products were analyzed. Besides, the phenomena associated these scenarios were discussed. Furthermore, the EOPs for the Chin-Shan and Lung-Men Nuclear Power Stations were used. The phenomena associated these scenarios were discussed and the conclusions based on a number of operator actions during the accident were also discussed. In general, EOPs are expected to enhance the safety of reactor during its normal operation and to mitigate the severity of an accident once the accident occurs. The result obtained for the ATWS case with EOPs shows that the operator actions has the potential to bring the plant into a safe-stable state. It is noted that the decay heat is one of the major concerns in the severe accident evaluation. Therefore, the heat exchanger in the residual heat removal (RHR) system plays an important role for the heat removal during ATWS. The base case studied is the ATWS with the EOPs, and sensitivity studies are investigated to understand the performance of heat exchanger using the MAAP code as the evaluation tool. The result shows that the entrance temperature of service water (TWSW), the mass flow rate of service water (WSWHX), and the NTU (number of trandfer unit) of the heat exchanger (NTUHX) have a major impact on the effectiveness of the RHR heat exchanger to remove the heat generated during the ATWS accidents. In other words, the capacity of RHR heat exchanger will increase with a decrease of TWSW, an increase of WSWHX or an increase NTUHX. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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