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Predictive Modeling of Baffle-Former Bolt Failures in Pressurized Water Reactors

  • Gregory A. Banyay
  • Matthew H. Kelley
  • Joshua K. McKinley
  • Matthew J. PalamaraEmail author
  • Scott E. Sidener
  • Clarence L. Worrell
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

Baffle-former bolt failures have been observed in recent inspections of pressurized water reactors (PWRs). These failures are understood to be primarily caused by irradiation-assisted stress corrosion cracking (IASCC). A prognostic method has been developed for simulating the degradation of baffle-former bolts due to IASCC. The method characterizes the evolution of stress in a reactor environment, as well as the redistribution of stress amidst neighboring bolt failures. Empirically-validated Weibull parameters are utilized in a stochastic framework, and the model is exercised as a Monte Carlo simulation to evaluate a range of plausible scenarios from which trends of bolt failure rates and patterns can be determined. This semi-empirical methodology is informed by both operating experience and a more detailed, predictive finite element analysis model that encompasses the full range of phenomenological effects common to the operating environment within a PWR.

Keywords

Baffle-former bolt Stochastic Semi-empirical Reliability 

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Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  • Gregory A. Banyay
    • 1
  • Matthew H. Kelley
    • 1
  • Joshua K. McKinley
    • 1
  • Matthew J. Palamara
    • 1
    Email author
  • Scott E. Sidener
    • 1
  • Clarence L. Worrell
    • 1
  1. 1.Westinghouse Electric Company LLCCranberry TownshipUSA

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