Experimental results from a test performed on the T-joint to pressurizer of WWER 440 type 213 NPP

A test was conducted on a T-joint used in the primary coolant loop. The T-joint was a replica of that between the surge line (connected to the pressurizer) and the primary coolant loop. The test was carried out in 2 stages, designed to simulate a specific reactor event and to determine the failure load. During the first stage, the experimental vessel was held at the normal operating temperature (about 300 degC) and pressure (12.5 MPa), and a force was applied to the branch to simulate the bending moment during the event. The vessel was depressurized for the second stage test, and the bending moment was applied until the limiting load was reached. The stability of the component was demonstrated in both stages of the experiment. In the second stage, ductile tearing was observed to a large extent