國聖電廠類福島全黑事故之模擬與分析

Simulation and Analysis of Kuosheng NPP Station Blackout Based on Fukushima Accident

林冠源(Lin, Kuan Yuan)

指導教授 ： 施純寬 ； 王仲容

國立清華大學/原子科學院/核子工程與科學研究所/碩士(2012年)

摘要

本論文主要模擬國聖電廠發生類似福島事件之事故，透過不同條件的假設，評估核電廠安全系統的應付能力，並提供事故發生時動作決策時機上的參考。情境模擬以電廠全黑為基礎，並假設所有緊急爐心冷卻系統皆失效，於爐心水位降至三個不同高度(1)TAF，(2)爐心裸露1/3高度，(3)BAF時啟動自動釋壓系統洩壓，生水於爐心壓力降至低壓0.779MPa時注入，全部分析以燃料護套溫度(PCT)不超過明顯開始氧化之限值1088.706K為最大前提，以最小流量、時間兩種角度去評估分析結果。本研究所使用之TRACE程式為美國核管會最新發展的一套熱水流安全分析程式，可廣泛的應用於輕水式核能電廠的各種暫態與冷卻水流失事故的分析。為了提升核二廠TRACE模式之可信度，本論文使用100%功率負載棄載啟動測試進行驗證並得到良好結果。而本論文之主要分析結果顯示，國聖電廠既有之生水系統設計足以應付類似福島之事故，且在充足的設計流量下，延長了動作決策時機的範圍，能有效地緩和此類事故在時間上的急迫性。

關鍵字

福島事件 ； 電廠全黑 ； TRACE ； 燃料護套尖峰溫度 ； 生水

並列摘要

In this research, the management ability of Kuosheng Nuclear Power Plant’s safety system is evaluated in different conditions through simulates a situation similar to Fukushima accident. In addition, the decision-making strategies during such severe accident are provided in this research as well. The situation simulation is based on SBO and assumes that all the Emergency Core Cooling Systems fail. The Automatic Depressurization System is activated under the conditions of three different core water levels (1) TAF, (2) one-third of fuel rods uncovered, (3) BAF. When the core vessel reaches the low pressure of 0.779 MPa, the alternate water system is activated in sequent. All the analyses presuppose that the peak cladding temperature (PCT) does not exceed the limit of 1088.706K and the analysis results are evaluated in two considerations which are minimum alternate water flow and time scale. The analysis code used in this research, TRACE (TRAC/RELAP Advanced Computational Engine), is a modernized thermal-hydraulic code developed by the U.S NRC. It can perform best-estimate analyses of loss of coolant accidents (LOCAs), operational transients, and other accident scenarios in light-water reactors (LWRs). In order to enhance the reliability of Kuosheng TRACE model, 100% power load rejection start up test is chosen in this research and the verified results are in agreement on test data. Furthermore, the main analysis result of this research indicates that the alternate water system installed in Kuosheng NPP can cope with a similar accident as severe as Fukushima event. Besides, the design of sufficient flow rate extends the time needed for decision-making and effectively mitigates the urgency when such accident occurs.

並列關鍵字

Fukushima Accident ； Station Blackout ； TRACE ； PCT ； Alternate Water System

參考文獻

[9] 李京翰，「核一廠TRACE模式的建立與驗證」，國立清華大學核子工程與科學研究所，碩士論文，中華民國九十八年

[10] 陳龍文，「核二廠TRACE模式的建立與驗證」，國立清華大學核子工程與科學研究所，碩士論文，中華民國九十八年七月

[15] 陳淑娟，「TRACE程式之中子動力模式研究與應用」，國立清華大學核子工程與科學研究所，碩士論文，中華民國九十九年七月

[2] U. S. Nuclear Regulatory Commission, “ Title 10, Code of Federal Regulations”, 2012

[3] U. S. Nuclear Regulatory Commission, “Reactor Safety Study: An Assessment of Accident Risks in U.S Commercial Nuclear Power Plants”, WASH-1400, 1975