Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Simulation of Asymmetric Fuel Thermal Behavior Using 3D Gap Conductance Model

3 차원 간극 열전도도 모델을 이용한 핵연료봉의 열적 비대칭 거동 해석

  • 강창학 (KAIST 기계공학부) ;
  • 이성욱 (KAIST 기계공학부) ;
  • 양동열 (KAIST 기계공학부) ;
  • 김효찬 (한국원자력연구원 경수로핵연료기술개발부) ;
  • 양용식 (한국원자력연구원 경수로핵연료기술개발부)
  • Received : 2014.06.26
  • Accepted : 2014.11.19
  • Published : 2015.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

A fuel assembly consists of fuel rods composed of pellets (UO2) and a cladding tube (Zircaloy). The role of the fuel rods in the reactor is to generate heat by nuclear fission, as well as to retain fission products during operation. A simulation method using a computer program was used to evaluate the safety of the nuclear fuel rods. This computer program has been called the fuel performance code. In the analysis of a light water reactor fuel rod, the gap conductance, which depended on the distance between the pellets and cladding tube, mainly influenced the thermomechanical behavior of the fuel rod. In this work, a 3D gap element was proposed to simulate the thermo-mechanical behavior of the nuclear fuel rod, considering the gap conductance. To implement the proposed 3D gap element, a 3D thermo-mechanical module was also developed using FORTRAN90. The asymmetric characteristics of the nuclear fuel rod, such as the MPS (missing pellet surface) and eccentricity, were simulated to evaluate the proposed 3D gap element.

원자력 발전소의 반응로에는 핵분열 에너지를 생성하고 방사성 물질의 유출을 막는 핵연료 집합체가 있으며, 이러한 집합체는 핵연료와 피복관으로 구성되어 있는 핵 연료봉으로 구성되어 있다. 원자로에서 핵연료봉 거동의 안전성을 평가하기 위해 해석적인 방법을 적용하며 이러한 평가 코드를 핵 연료 성능 코드라 한다. 경수로 핵연료 해석에서는 간극의 두께에 따라 열전도도가 크게 영향을 받는 간극 열전도도가 주요 거동해석에 영향을 미친다. 본 연구에서는 간극 두께에 따라 열전도도가 변화하는 3 차원 간극 요소(Gap element)를 제안하였으며, 이를 적용하기 위해 3 차원 열탄성 모듈을 FORTRAN90을 이용하여 개발하였다. 제안된 3 차원 간극 요소를 이용하여 핵 연료봉에서 발생할 수 있는 비대칭적인 형상인 핵 연료 표면에 결함이 생긴 경우 MPS(Missing Pellet Surface)와 핵연료봉의 편심(Eccentricity of the nuclear fuel rod) 형상에 대하여 3 차원 해석을 진행하였다.

Keywords

References

  1. Lamarsh, J.R. and Baratta, A.J., 2012, Introduction to Nuclear Engineering, Third edition, Prentice-Hall, Inc.
  2. Hikimet, S. A. and Ortego, P., 2005, "A Review of Nuclear Fuel Performance Codes," Progress in Nuclear Energy, Vol. 46, No. 2, pp. 127-141. https://doi.org/10.1016/j.pnucene.2005.01.004
  3. Thouvenin, G., Ricaud, J. M. and Michel, B., 2006, "ALCYONE: the PLEIADES Fuel Performance Code Dedicated to Multidimensional PWR Studies," TopFuel 2006 meeting
  4. Williamson, R. L. and Novascone, S. R., 2012, "Application of the BISON Fuel Performance Code to the FUMEX-III Coordinated Research Project," INL/EXT-12-25530, Idaho National Laboratory
  5. Kim, H.C., Yang, Y.S. and Koo, Y.H., 2014, "Development of Multidimensional Gap Conductance Model for Thermo-Mechanical Simulation of Light Water Reactor Fuel," Trans. Korean Soc. Mech. Eng. A, Vol. 38, No. 2, pp. 157-166. https://doi.org/10.3795/KSME-A.2014.38.2.157
  6. Intel$^{(R)}$, 2013, "User and Reference Guide for the Intel$^{(R)}$ Fortran Compiler."
  7. Ross, A.M. and Stoute, R.L., 1962, "Heat Transfer Coefficient Between UO2 and Zircaloy-2," Atomic Energy of Canada, Technical Report, ACEL-1552.
  8. Aleshin, Y., Beard, C., Mangham, G., Mitchell, D., Malek, E. and Young, M., 2010, "The Effect of Pellet and Local Power Variation on PCI Margin," in: Proceeding of Top Fuel 2010.
  9. Spencer, B.W., Hales, J.D., Novascone, S.R and Williamsonand, R.L., 2012, "3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods," INL/CON-12-24745, Idaho National Laboratory.
  10. Lee, J.S., Yoo, J.S., Kim, H.K., Kim, K.J., Jeon, K.L., Mitchell, D. and Aleshin, Y., 2009, "Stress Analysis for Cladding Tube and Fuel Pellet with Missing Pellet Surface," Transactions of the Korean Nuclear Society Autumn Meeting, Gyeongju, Korea, pp.29-30.