Estimation of Fracture Parameters for Leak-before-Break Assessment on Elevated Temperature

When the liquid sodium leaks this interaction may cause the fire that is harmful to safety of the reactor. Therefore, it is necessary to prevent against sodium fire in SFRs. Leak-before-Break(LBB) concept, had been devised for this purpose and has following advantage than Double-ended Guillotine Break(DEGB) design. If DEGB is excluded, the number of extinguish facilities and firewalls against the sodium fire can be minimize. LBB concept, has been well established and had many experience in regard of light water reactors(LWRs). But LBB assessment to SFRs is more complicated because SFRs is operated on elevated temperature region. On this region, because creep damage occurs to material and grows defects LBB assessment to SFRs should be considering creep effects. The procedure and method for this purpose are provided RCC-MRx A16 that is France code. To calculate fracture parameters such as K and J are required to some coefficients and equations which have been limited in RCC-MRx A16. Thus, in this study obtained K and J using finite element analysis for the sub-model including the crack. In this study, fracture parameters for LBB assessment were estimated by finite element analysis. This result will be applicable to LBB assessment of PGSFR