Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Statistical analysis of parameter estimation of a probabilistic crack initiation model for Alloy 182 weld considering right-censored data and the covariate effect

  • Park, Jae Phil (School of Mechanical Engineering, Pusan National University) ;
  • Park, Chanseok (Department of Industrial Engineering, Pusan National University) ;
  • Oh, Young-Jin (Korea Electric Power Corporation (KEPCO) Engineering and Construction, Co, Ltd) ;
  • Kim, Ji Hyun (Department of Nuclear Engineering, School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST)) ;
  • Bahn, Chi Bum (School of Mechanical Engineering, Pusan National University)
  • Received : 2017.06.05
  • Accepted : 2017.09.20
  • Published : 2018.02.25
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Abstract

To ensure the structural integrity of nuclear power plants, it is essential to predict the lifetime of Alloy 182 weld, which is used for welding in nuclear reactors. The lifetime of Alloy 182 weld is directly related to the crack initiation time. Owing to the large time scatter in most crack initiation tests, a probabilistic model, such as the Weibull distribution, has mainly been adopted for prediction. However, since statistically more advanced methods than current typical methods may be applied, we suggest a statistical procedure for parameter estimation of the crack initiation time of Alloy 182 weld, considering right-censored data and the covariate effect. Furthermore, we suggest a procedure for uncertainty evaluation of the estimators based on the bootstrap method. The suggested statistical procedure can be applied not only to Alloy 182 weld but also to any material degradation data set including right-censored data with covariate effect.

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