AP1000 TRACE/SNAP Modeling and Analysis on Loss of AC Power to the Plant Auxiliaries Accident

王凱

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(2013年)

摘要

本文研究目的是使用TRACE程式建立AP1000核能電廠模式并根據西屋公司數據驗證其準確性。文章第一部份分別建立了三維爐心，蒸汽產生器和其他組件的TRACE模式，并驗證了其符合西屋公司設計。隨後，包含一次側，二次側和被動式系統的電廠模式及其控制系統被建立，並用暫態模擬穩態的方式獲得電廠100%額定功率的運轉參數。該參數與西屋相關數據比較，顯示了良好的一致性。故證明該模式的準確行，並可應用於以後的暫態分析。
本文第二部份應用建立好的AP1000 TRACE模式對電廠輔助設施失去AC電源事故進行了分析。該事故被西屋公司列為Condition II 事故。通過和西屋公司LOFTRAN程式計算結果比較，TRACE程式計算結果和其較為接近。該結果還證明了AP1000被動系統在電廠失去所有AC電源時，無需人為操作就能夠建立和維持安全停爐狀態，並對爐心進行有效冷卻，從而緩解了事故的後果，防止了爐心熔毀和放射性物質外泄等嚴重事故的發生。
本文成功建立了AP1000 TRACE/SNAP 模式。在商業運轉之後，該模式可以通過啟動測試數據進行進一步驗證。另外，該研究還建立了模式的動畫檔來更加直觀的檢視電廠熱水流參數。總之，該模式在未來可以被用在AP1000電廠的安全分析並為其運轉提供更多參考。

關鍵字

AP1000 ； TRACE ； loss of AC power to the station auxiliaries

並列摘要

The objectives of this thesis are to establish AP1000 TRACE model via SNAP interface, and to verify its accuracy comparing with Westinghouse design. In the beginning, 3D vessel, steam generator and other components were separately built based on Westinghouse Design Document and independent tests were conducted to assess their accuracy. The simulation results obtained by TRACE show a good agreement with design. After that, the plant with main RCS and PXS components was modeled and the steady state calculation was implemented to acquire 100% rated power operation condition by using the transient simulation method. The calculated data was compared with Westinghouse design and prove the mode's accuracy, which can be applied to simulate the accident transient behavior in future.
In this research, loss of AC power to the station auxiliaries accident which is considered as Condition II event in Westinghouse Design Document was analyzed using AP1000 TRACE model. Compared with the calculated results of LOFTRAN code developed by Westinghouse, the data simulated by TRACE shows a good agreement and reveals that the passive safety systems could establish and maintain a safety shutdown condition for the plant with the effective core cooling, mitigating the accidental consequence without operator actions when loss of all AC power sources. Thus the severe accident consequences such as the reactor core melting and radioactive leakage would be avoided.
In conclusion, AP1000 TRACE/SNAP model has been established. After the commercial operation, this model could be verified by using startup tests. The animation of the model was also created to observe the thermal hydraulic parameters of plant in real time. This model could be used in safety analysis in future and offers more references for AP1000 safety operation.

參考文獻

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