在2011年，日本所發生的福島事件使得全世界更加重視核能，許多核能研究機構或是管制單位都被要求更深入的檢討核能安全，其中氫氣的處理以及用過燃料池失去冷卻水源事故的應對皆被列為最受注目的議題之中。
本研究參考核能三廠的用過燃料池結構設計以及PWR核燃料組件的構造，進行用過燃料池的熱水流分析。用過燃料池是一種相當特殊的模型，池內流場具備了自然對流特性以及流體通過燃料棒束間的相互流動特性，自成一格。在計算資源貧乏的過去，想研究用過燃料池都必須透過多孔隙物質(Porous medium)模式來模擬，縱使其結果能夠提供部分實境，不知其內細部流場的變化實屬可惜。
本研究的目的在於，提供用過燃料池內細部的流場及溫度場實景，並分析在正常情況下或是發生喪失冷卻水源補充的事故時，護套表面上熱傳系數的變化。本研究使用內含96GB記憶體的8CPU工作站，並以計算流體力學工具STAR-CCM++對停機後100小時退出之用過燃料組件進行暫態的自然對流分析。所計算之結果用與RELAP 5內所使用之經驗式比較，並評估最先發生局部沸騰的位置以及最熱中心通道在使用一般經驗式的保守度，最後池水達到沸騰的時限以供參考。

The concerns on nuclear safety and security have been increased tremendously after the Fukushima Daiichi nuclear disaster on 11 March 2011 in Japan. Issues on the control of hydrogen concentration and the efficient cooling of spent fuel pools after water implementation are the most essential concerns in recent years.
This study conducts the thermal hydraulic analysis for the spent fuel pool referred the designs of Maanshan nuclear power plant in Taiwan. Natural circulation and the cross flow inside the fuel bundle are the major features inside the spent pool and need to be investigated by an appropriate model. In the previous investigations, the application of porous models had been employed in numerical computations for spent fuel pool due to the limitations of simulation resources. Thus, only part of the physics and thermo-hydraulic information had been obtained by the simplified model.
This study aims to provide the detailed phenomena of flow fluid field and temperature field as well as the heat transfer coefficients in normal or abnormal conditions. The numerical computations are conducted by commercial CFD code STAR-CCM+ with 8 CPUs and 96 GB memories. The abnormal conditions include the transients of the flow and temperature distributions for one spent fuel assembly starting the assembly removed from reactor core at 100 hours. The heat transfer capability such as the calculated heat transfer coefficients is compared to the correlations used in RELAP 5, so that justifications can be made by using these correlations in RELAP 5

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