Effect of normal operating condition analysis method for weld residual stress of CRDM nozzle in reactor pressure vessel

Hyun Suk Nam, Hong Yeol Bae, Chang Young Oh, Ji Soo Kim, Yun-Jae Kim

Research output: Contribution to journalArticle


In pressurized water nuclear reactors (PWRs), the reactor pressure vessel (RPV) upper head contains penetration nozzles that use a control rod drive mechanism (CRDM). The penetration nozzle uses J-groove weld geometry. Recently, the occurrence of cracking in alloy 600 CRDM penetration nozzle has increased. This is attributable to primary water stress corrosion cracking (PWSCC). PWSCC is known to be susceptible to the welding residual stress and operational stress. Generally, the tensile residual stress is the main factor contributing to crack growth. Therefore, this study investigates the effect on weld residual stress through different analysis methods for normal operating conditions using finite element analysis. In addition, this study also considers the effect of repeated normal operating condition cycles on the weld residual stress. Based on the analysis result, this paper presents a normal operating condition analysis method.

Original languageEnglish
Pages (from-to)1159-1168
Number of pages10
JournalTransactions of the Korean Society of Mechanical Engineers, A
Issue number9
Publication statusPublished - 2013 Jan 1



  • FE analysis
  • Normal operating condition
  • Reactor upper vessel head
  • Weld residual stress

ASJC Scopus subject areas

  • Mechanical Engineering

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