Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Numerical Simulation on the Spreading and Heat Transfer of Ex-Vessel Core Melt in a Channel

전산해석을 이용한 원자로 노심 용융물의 노외 거동 및 열전달 특성 분석

  • Ye, In-Soo (School of Mechanical Engineering, Sungkyunkwan Univ.) ;
  • Ryu, Chang-Kook (School of Mechanical Engineering, Sungkyunkwan Univ.) ;
  • Ha, Kwang-Soon (Dept. of Nuclear Safety Research, Korea Atomic Energy Research Institute) ;
  • Song, Jin-Ho (Dept. of Nuclear Safety Research, Korea Atomic Energy Research Institute)
  • 예인수 (성균관대학교 기계공학부) ;
  • 류창국 (성균관대학교 기계공학부) ;
  • 하광순 (한국원자력연구원 열수력안전연구부) ;
  • 송진호 (한국원자력연구원 열수력안전연구부)
  • Received : 2010.12.16
  • Accepted : 2011.01.07
  • Published : 2011.04.01
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Abstract

In the unlikely of nuclear reactor meltdown, the leaked core melt or corium must be contained in a device called core-catcher so that the corium can be cooled and stabilized. The ex-vessel behavior of corium involves complex physical and chemical mechanisms of flow propagation, heat transfer, and reactions with sacrificial substrates. In this study, the detailed characteristics of corium flow and heat transfer were investigated by using a commercial CFD code for VULCANO VE-U7 test reported in the literature. The volume-of-fluid (VOF) model was used to predict the interfacial surface formation of corium and the surrounding air, and the discrete ordinate model was adopted to calculate radiation between corium and the surroundings. It was found that cooling via radiation through the top surface of corium had a dominant effect on the temperature and viscosity profiles at the front of the corium flow.

원자로의 노심 손상에 따른 노심 용융물의 노외 유출시 코어캐처라고 불리는 설비를 통해 용융물을 억제하고 냉각시키게 된다. 이 때 노외 노심용융물의 거동은 희생물질과의 반응을 포함한 복잡한 물리적, 화학적 현상에 의해 결정된다. 이 연구는 기존의 용융물 거동 실험결과에 대해 용융물의 유동과 열전달의 세부적인 특성을 상용코드를 이용해 해석하여 검증함으로써 코어캐처의 설계에 활용할 수 있도록 하기 위한 것이다. 단순화된 채널에서 시간에 따른 용융물과 공기의 이상유동과 복사열전달을 VOF 모델과 구분종좌법을 적용하여 비정상상태에서 해석한 결과, 열전달에 따른 용융물 내부의 온도 변화 및 이에 따른 점성 변화 등을 예측할 수 있음을 확인하였다. 이러한 접근방식을 기초로 향후 용융물의 조성, 유량 및 용도 등의 조건에 따른 용융물의 거동에 대한 자세한 평가가 필요하다.

Keywords

References

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