The containment atmosphere, in the cases of loss of coolant accident or major steam line break, is pressurized by the release of high energy coolant or steam into the containment atmosphere, and this pressure rise imposes a potential threat to the structural integrity of the containment building which is the final barrier against the release of radioactive materials to the environments. The peak containment pressure is highly dependent on the heat transfer coefficient between the containment atmosphere and heat absorbing structures.
The estimate of heat transfer coefficient in this study uses the well-known correlations. Nusselt heat transfer coefficient for pure vapors is calculated and then corrected for the influence of noncondensable air using the various correlations according to the laminar or turbulent condition. The numerical calculation using the proposed model is accomplished employing the data measured in Carolinas Virginia Tube Reactor containment test 3. The calculated values for condensing heat transfer coefficient are compared with Tagami and Uchida correlations which are widely used in containment analysis. The calculated heat transfer coefficients are incorporated into the CONTEMPT-LT code as time dependent input and then have predicted the containment atmosphere pressure and temperature transient for CVTR test 3.
冷却材 喪失事故(LOCA)나 主症氣配官破熱事故(MSLB)時에 格納容器로부터의 熱除去 能力(卽 熱傳達係數)의 推定은 格納容器의 基本的인 設計變數인 최고 압력 및 온도의 예측에 있어서 매우 중요하다.
格納容器내에는 非凝縮性 가스인 空氣가 多量 存在하는데 本 모델에서는 純醉 蒸氣만 存在한다는 假定下에서 熱傳達係數를 구한 다음에 非凝縮性 가스의 存在로 인한 熱傳達의 減少效果를 導入하여 凝縮 熱傳達係數를 計算하였다.
유일한 대규모 格納容器 實驗인 CVTR 資料를 異容하여 凝縮 熱傳達係數를 桂酸하여 現在 원자력발전소의 LOCA 및 MSLB 時에 格納容器의 安全 解析에서 公式的으로 사용되고 있는 Tagami와 Uchida 熱傳達係數 關係式과 비교하였으며 또한 桂酸된 熱傳達係數는 格納容器의 安全解析用 電算코드인 CONTEMPT-LT에 時間에 따른 入力으로 주어져 CVTR 格納容器에 對하여 壓力 및 溫度를 豫測하여 實驗結果와 比較하였다.
