장윤석 교수

Abstract Since thermal aging embrittlement (TE) causes loss of fracture toughness and may lead to failure, it is one of structural integrity issues to be assessed in nuclear industry. In this study, crack growth simulation by using extended finite element method (XFEM) was carried out for CF8M base metal and ER316L weld metal, which are typical vulnerable materials. First, user subroutines were constructed to incorporate variation of mechanical properties of two materials due to the TE. In parti

Improvement of numerical analysis methods has been required to solve complicated phenomena that occur in nuclear facilities. Particularly, fluid-structure interaction (FSI) behavior should be resolved for accurate design and evaluation of complex reactor vessel internals (RVIs) submerged in coolant. In this study, the FSI effect on dynamic characteristics of RVIs in a typical 1,000 MWe nuclear power plant was investigated. Modal analyses of an integrated assembly were conducted by employing the

External reactor vessel cooling (ERVC) for in-vessel retention (IVR) has been considered one of the most useful strategies to mitigate severe accidents. However, reliability of this common idea is weakened because many studies were focused on critical heat flux whereas there were diverse uncertainties in structural behaviors as well as thermal–hydraulic phenomena. In the present study, several key factors related to molten corium behaviors and thermal characteristics were examined under multi-la

Background: Steam explosions may occur in nuclear power plants by molten fuel–coolant interactions when the external reactor vessel cooling strategy fails. Since this phenomenon can threaten structural barriers as well as major components, extensive integrity assessment research is necessary to ensure their safety. Method: In this study, the influence of yield criteria was investigated to predict the failure of a reactor cavity under a typical postulated condition through detailed parametric fin

Mitigation of primary water stress corrosion cracking (PWSCC) is a significant issue in the nuclear industry. Advanced nickel-based alloys with lower susceptibility have been adopted, although they do not seem to be entirely immune from PWSCC during normal operation. With regard to structural integrity assessments of the relevant components, an accurate evaluation of crack growth rate (CGR) is important. For the present study, the extended finite element method was adopted from among diverse mes