Journal of Surface Science and Engineering (한국표면공학회지)

The Korean Institute of Surface Engineering (한국표면공학회)
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Hydrogen Effect on the Oxidation of Zr-Alloy Claddings under High Temperature

수소화물에 의한 Zr 합금의 고온산화 가속효과

  • Jung, Yunmock (Korea Atomic Energy Research Institute) ;
  • Ha, Sungwoo (Department of Nuclear Engineering, Kyunghee University) ;
  • Park, Kwangheon (Department of Nuclear Engineering, Kyunghee University)
  • Received : 2015.11.16
  • Accepted : 2016.07.29
  • Published : 2016.08.31
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Abstract

The operation method of nuclear power plants is currently changing to high burn-up and long period that can enhance economics and efficiency of the plant. Since nuclear plant operation environment has been becoming severe, the amount of absorbed hydrogen also has increased. Absorbed hydrogen can be fatal securing safety of nuclear fuel cladding in case of Loss of Coolant Accidents(LOCA). In order to examine the impact of hydride on high-temperature oxidation, high-temperature oxidation experiment was performed on normal Zry-4 cladding and on Zry-4 cladding where hydrogen is charged in air pressure steam atmosphere under the $950^{\circ}C$ and $1000^{\circ}C$. According to the results, while oxidation acceleration due to charged hydrogen was not observed prior to breakaway oxidation creation, oxidation began to accelerate in cladding where hydrogens charged as soon as the breakaway oxidation started. If so much hydrogen are charged in the cladding, equiaxial monoclinic phase to unstable of stress is formed and it is presumed that oxidation is accelerated because nearby stress caused a crack in equiaxial phase, and that makes corrosion resistance decline sharply.

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References

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