Improvement of LBW quality of Zircaloy-4 Spacer Grids for PWR Fuel Assembly

경수로 원전연료용 지르칼로이-4 지지격자 레이저용접품질 개선

  • Kim, Soo-Sung (Department of PWRs Nuclear Fuel Development, Korea Atomic Energy Research Institute) ;
  • Song, Kee-Nam (Department of PWRs Nuclear Fuel Development, Korea Atomic Energy Research Institute) ;
  • Han, Hyoung-Jun (Department of Technology Development, Ltek)
  • 김수성 (한국원자력연구소 경수로핵연료개발부) ;
  • 송기남 (한국원자력연구소 경수로핵연료개발부) ;
  • 한형준 (엘텍 기술개발부)
  • Published : 2006.10.31


A spacer grid assembly, which is an interconnected array of slotted grid straps and is welded at the intersections to form an egg crate structure, is one of the main structural components of the nuclear fuel assembly for Pressurized Water Reactors (PWRs). The weld quality of spacer grids in PWRs fuel is extremely important for the fuel assembly performance in the nuclear renter. The spacer grid welds are currently evaluated mainly by the metallographic examination although it reveals only cross-points which are welded by the laser beam. This experiment is also to compare the weldability of Zircaloy-4 spacer grids using by the GTA and LB. The effect of node geometries of spacer grids for the GTAW and LBW has been studied and optimum conditions of spacer grid welding have been found. Microstructures and micro-hardness of the GTA and LB welded zones have been also compared.



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