Safety against bursting of reactor pressure vessel nozzles under internal pressure

Assessment using fracture mechanics methods of nozzle corner cracks of reactor pressure vessels under internal bursting load. Calculation, with the aid of a finite element program, of stress-intensity factors K for different cracks presumed at the inside corner of a coolant inlet nozzle of a pressurized-water reactor. Introduction of special elements for the crack tip range and also of precise methods for the derivation of K values for four different crack sizes along with their deviations around the crack profile. Comparison of the calculated K factors with the results for different crack-affected models, partly using approximation solutions. (orig.)