龍門核能電廠預期暫態未急停之飼水系統事故PCTRAN模擬分析

PCTRAN Analysis for Feedwater System Accident in Lungmen Nuclear Power Plant ATWS

杜宛慈(Wantzu Tu)

指導教授 ： 施純寬

國立清華大學/原子科學院/工程與系統科學系/碩士(2007年)

摘要

近幾年來陸續修改擴充後的PCTRAN版本，獨立出飼水系統和控制棒系統的監控介面，加強系統模擬的多樣性及準確性；本研究利用此版本，進行龍門核能電廠之飼水相關的預期暫態未急停(ATWS)事故模擬分析。預期暫態未急停為核能電廠發生預期運轉事件導致反應器保護系統動作，但無法使反應爐急停；此時控制棒替代插入系統(ARI)需啟動控制棒插入爐心，使反應器停機，若制棒替代插入系統失效則藉由微調控制棒驅動機構插入(FMCRD Run-in)控制棒，若發生最嚴重的情形ARI和FMCRD雙雙失效，最後則由備用硼液控制系統注入硼液，達到安全停機之目的。
　　本論文將分析三個飼水相關案例：喪失飼水、喪失飼水加熱以及飼水控制器失效以致輸出最大需求，此三案例分別藉由低水位、手動和高壓力三種不同的啟動方式使緩和設備動作。並就模擬結果和廠家提供之初期安全分析報告[1]比對，經本研究驗證，確定擴充後新增介面功能的模擬結果之正確性及模擬系統之可靠性。

關鍵字

龍門電廠 ； 飼水系統 ； 預期暫態未即停

並列摘要

The new expanded version of PCTRAN has individualized the Feedwater system and Control Rod system and made users able to control and monitor the two systems in individual window. It helps to enhance the diversity and accuracy of simulation. We utilize the expanded PCTRAN to simulate and analyze the events of Anticipated Transient Without Scram (ATWS) of LungMen NPP in feedwater system. Anticipated transient without scram means an anticipated operational occurrence followed by the failure of the reactor trip portion of the protection system. At this moment alternate rod injection (ARI) system starts to insert the control rods. If ARI system fails, the control rods are inserted by Fine Motion Control Rod Drive (FMCRD) run-in system. If ARI and FMCRD systems both fail, standby liquid control system (SLCS) injects into the reactor pressure vessel a borated water solution.

We analyzed three ATWS events involved feedwater systems: Loss of Feedwater, Loss of Feedwater Heating and The Feedwater Controller Failure to Maximum Demand. They are triggered separately by low water level, manual and high pressure. We contrasted the results of simulation with PSAR[1]. After a series of verifications, we affirmed the accuracy and credibility of the results of the expanded PCTRAN.

參考文獻

[4] 陳俊宇, “PCTRAN-ABWR緊急爐心冷卻系統模式擴充”, 國立清　　華大學工程與系統科學系, 2005

[5] Hui-Wen Huang, Wan-Tzu Tu, Chunkuan Shih, Swu Yih, Cherng-Tsong Kuo, Ming-Huei Chen, Chun-Yu Chen, Wei-Yi Yang, Development of Evaluation Method for Software Safety Analysis Techniques, 15PBNC, Sydney, 15 - 20 October 2006.

[6] 楊偉義, “龍門核能電廠預期暫態未急停之蒸汽管路系統事故PCTRAN模擬分析”, 國立清華大學工程與系統科學系, 2007

[8] 黃揮文, “運轉員與數位儀控系統介面互動表現對核能電廠安全影響之研究” ,國立清華大學工程與系統科學系, 2007

[1] 核四廠初期安全分析報告(PSAR)