進步型沸水式反應器再循環流量控制之模擬與分析

Modeling and Analysis of ABWR Recirculation Flow Control

蔣瑞豐(Ray-Feng Chiang)

指導教授 ： 鄧治東

中原大學/工學院/機械工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700092

摘要

進步型沸水式反應器（Advanced Boiling Water Reactor, ABWR）之反應爐冷卻水再循環係採爐內泵打水方式，設計上在反應爐降水區對稱裝置有十台單級葉片混流式水泵，負責提供強制性的循環冷卻水來達到控制功率的目的。現行運轉規範要求電廠在正常運轉時，至少需九台爐內泵運作才可維持滿載，亦即在ㄧ台爐內泵不可用之情況下，仍可維持滿載發電。為避免爐內泵跳脫造成無謂的停機，並增加電廠之運轉餘裕，實有必要於核四ABWR電廠正式商轉前，深入有關爐內泵運轉特性方面的研究。
本研究主要是建立核能四廠雷傳程式（RETRAN-02）程式再循環流量控制模組，以100 %功率及85 %爐心流量為初始條件，進行與爐內泵運轉有關穩態運轉、負載追隨、爐內泵跳脫暫態及喪失飼水加熱器事件等，來驗證再循環流量控制模組因應該等暫態之反應正確性，同時計算爐內泵跳脫暫態之爐心最熱燃料束之ΔCPR值，確認燃料再該等暫態下之安全性。
研究結果顯示，所建立之核四廠雷傳程式再循環流量控制系統模組伴隨壓力控制系統模組及三元飼水控制系統模組，可成功地模擬複雜的核能電廠控制邏輯及計算出穩態及暫態中系統熱水流重要參數之反應。研究成果並可改進以往繁複瑣碎地穩態初始化步驟，在短時間（約50秒）即進入穩態之狀況。本研究分析結果顯示，爐內泵跳脫一、二台之暫態，不會影響運轉安全，而爐內泵跳脫三台之暫態，其反應爐功率會降低至94.9 %額定值，爐心流量會降至66 %額定值，反應爐壓力則降低至1,033 psia，暫態結果未進入功率/流量圖中不穩定運轉區，爐心最熱燃料束之ΔCPR值仍在初期安全分析報告之安全限值內。
由上述可知本研究可成功的模擬負載追隨、爐內泵跳脫ㄧ台以上運轉條件及喪失飼水加熱暫態事故，運跑之數據趨勢已有相當的合理性，在國內已建立本土化核能電廠穩態與暫態事故分析之能力。

關鍵字

龍門電廠 ； 進步型沸水式反應器 ； 雷傳程式（RETRAN-02）程式

並列摘要

The major improved features of the advanced boiling water reactor（ABWR）, compared to conventional BWR, are the installation of ten reactor internal pumps peripherally bottom-mounted in the lower plenum and downcomer regions. For safe full-power operation, the Technical Specification of the plant operation requires that at least nine pumps be in operation, which means that it is not allowed to operate the plant when more than one reactor internal pumps are out of service. In order to prevent unnecessary plant shutdown and to increase the operating margin, it is essential to perform in-deep investigation for the operating characteristics of the reactor internal pumps and the associated recirculation flow control system.
In this study, efforts have been made to apply the RETRAN-02 code to the Lungman ABWR plants. The work focuses on modeling and simulating different transient cases for the ABWR plants, including steady state running, load following simulation test, more than one reactor internal pumps trip transient analysis, and loss of feedwater heater transient analysis. In addition, the delta critical power ratio（CPR）associated the transients has also been calculated to confirm whether the transient is thermal limiting.

The analysis results show that the response behavior of the recirculation flow control model is well predicted and the transient delta CPR is calculated to be non-limiting for the cases of the internal pump trip transient simulated in this study. The results also demonstrate that it is appropriate to apply the currently established model for further ABWR transient analysis in the future. It is recommended that more transients will be simulated during the start up stage and some tunning work on the setting of different controller needs to be performed in order to get more realistic response characteristic for the recirculation flow control system.

並列關鍵字

ABWR ； Lungmen Nuclear Power Plant ； RETRAN-02

參考文獻

7. Project Design Manual Revision 20, Taiwan Power Company Lungman Project Fourth Nuclear Power Plant Units.

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