- 學位論文
核四廠電廠預期暫態未急停狀況下嚴重事故導則之分析
A Study on the Severe Accident Guideline for the Fourth Nuclear Power Plant under Anticipate Transient Without Scram Condition
摘要
本研究係針對座落於北台灣的核四龍門電廠（Nuclear Power Plant, NPP）進行探討，電廠反應爐型式為馬克三式進步型沸水式反應爐（Advanced Boiling Water Reactor, ABWR），研究之模擬運跑係採用MAAP4.0.4程式，並依循緊急運轉程序書（Emergency Operator Procedure, EOP）與嚴重事故導則（Severe Accident Guideline, SAG）之運轉規範，進行多項嚴重事故之分析研究。 為評估緊急運轉程序書與嚴重事故導則於暫態過程中之可行性，以及於嚴重事故中運轉員之操作邏輯對事故的影響程度，Electric Power Research Institute（EPRI）與合作的公用事業，共同發展核能操作模組及分析工具（Nuclear Operator Response Modeling and Analysis Tool, NORMAT），即MAAP4.0.4程式。 個案模擬係針對核四龍門電廠於預期暫態未急停（Anticipate Transient Without Scream, ATWS）狀況下，進行五項事故模擬，個案一為穩態（Steady State）運跑，個案二為預期暫態未急停事故，個案三為依循緊急運轉程序書之預期暫態未急停事故，個案四為依循嚴重事故導則之預期暫態未急停事故，個案五為於預期暫態未急停事故且反應爐壓力槽破裂（RPV Failed）之狀況下，依循嚴重事故導則之程序進行模擬分析。 此外，核四龍門電廠所依循的運轉規範（緊急運轉程序書與嚴重事故導則），其事故之相關現象與運轉員之操作程序，皆予以探討並規範之。本研究之模擬結果顯示，依循運轉規範之程序，可有效的增加反應爐的安全性，並減緩嚴重事故之發展，由此可見，此兩項運轉規範所加入之運轉員操作邏輯，可使電廠不致惡化為嚴重事故，且能恢復至”安全穩定”的狀態。
並列摘要
This investigation presents a comparison of severe accident progression for several postulated accident sequences for representative Emergency Operator Procedure (EOP) and Severe Accident Guideline (SAG) strategies performed with the Modular Accident Analysis Program version 4.0.4 (MAAP 4.0.4) code on the fourth (Lung-Men) Nuclear Power Plant (NPP). Based on the Lung-Men NPP is a Mark-III Advanced Boiling Water Reactor (ABWR) NPP and located in northern Taiwan. Electric Power Research Institute (EPRI) and several collaborating utilities are sponsoring development of a Nuclear Operator Response Modeling and Analysis Tool (NORMAT) as a software environment (MAAP4.0.4) for integrating the effects of operator action into accident analyses, and as a test bed for evaluating the feasibility of EOPs and SAGs during the course of the transient. The study for the Lung-Men nuclear power plant under Anticipate Transient Without Scream (ATWS) simulations have been conducted. A total of five accident sequences were studied with both strategies. Case I assumed that the simulation of steady state, Case II assumed that the scenario of ATWS, Case III is the same as Case II, and according to the EOPs, Case IV is the same with case III, except that according to the SAGs, Case V assumed that the scenario of ATWS with Reactor Pressure Vessel (RPV) failed, and according to the SAGs. In general, the EOPs and SAGs for the Lung-Men Nuclear Power plant were used. The phenomena associated these scenarios were discussed and the results based on a number of operator actions during the accident were also discussed. In conclusions, EOPs and SAGs 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 and SAGs show that the operator actions have the potential to bring the plant into a “safe-stable” state.