In order to ensure safety and efficient state of nuclear power plant in the long time operation, it is necessary to figure out the acceptance table of defects of the primary loop to meet the requirement of rapid assessment in engineering. It is necessary to do the fracture mechanics and plastic limit load analysis for the cracked pipe. Through numerical simulation analysis, the rationality of adopting plastic limit load as the critical state of austenitic stainless steel structure with good fracture toughness is demonstrated. Based on the criterion of non-decreasing the plastic limit load in design state, the acceptance standard of defects for the austenitic stainless steel pipe is established in this paper. The results show that the defect acceptance size of the primary circuit pipe is close to that in the ASME code, but much larger than that of the RSE-M code, and the RSE-M code is too conservative.