Effects of repair weld of reactor pressure vessel upper head control rod drive mechanism penetration nozzle on J-Groove weldment using finite element analysis

Ju Hee Kim, Sam Hyeon Yoo, Yun Jae Kim

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In pressurized water reactors, the upper head of the reactor pressure vessel (RPV) contains numerous control rod drive mechanism (CRDM) nozzles. These nozzles are fabricated by welding after being inserted into the RPV head with a room temperature shrink fit. The tensile residual stresses caused by this welding are a major factor in primary water stress corrosion cracking (PWSCC). Over the last 15 years, the incidences of cracking in alloy 600 CRDM nozzles have increased significantly. These cracks are caused by PWSCC and have been shown to be driven by the welding residual stresses and operational stresses in the weld region. Various measures are being sought to overcome these problems. The defects resulting from the welding process are often the cause of PWSCC acceleration. Therefore, any weld defects found in the RPV manufacturing process are immediately repaired by repair welding. Detailed finiteelement simulations for the Korea Nuclear Reactor Pressure Vessel were conducted in order to predict the magnitudes of the repair weld residual stresses in the tube materials.

Original languageEnglish
Pages (from-to)637-647
Number of pages11
JournalTransactions of the Korean Society of Mechanical Engineers, A
Volume38
Issue number6
DOIs
Publication statusPublished - 2014 Jun
Externally publishedYes

Keywords

  • CRDM
  • Fe analysis
  • J-Groove weld
  • PWSCC
  • RPV
  • Repair weld
  • Shrink fitting

ASJC Scopus subject areas

  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Effects of repair weld of reactor pressure vessel upper head control rod drive mechanism penetration nozzle on J-Groove weldment using finite element analysis'. Together they form a unique fingerprint.

Cite this