AN EXPERIMENTAL LEAK TEST FACILITY FOR SUBCOOLED WATER LEAKAGES

This paper demonstrates the detail of an experimental leak test facility to simulate loss of coolant accident (LOCA) probabilities in primary heat transport pipelines of modern pressurized water reactors (PWRs). The facility was erected at Jadavpur University, Kolkata in collaboration with BARC, Mumbai under a project for reactor safety issues funded by BRNS, DAE, Govt of India. Unknown crack morphologies concerned were avoided by selecting artificially generated circumferential slits with rectangular projections on reactor grade Pipelines. Experiments were conducted in several phases with pressurized (maximum 90 bar) and hot (maximum 250ºc) subcooled liquid water to leak through the narrow slits on pipe wall oriented perpendicular to pipe flow direction. A bank of Leak flow data has been generated in a high depressurization flow domain (like 90 bar to atmospheric) and results have been compared with relevant code predictions, as a function of slit upstream stagnation pressure, stagnation subcooling and slit dimensions. Thermal hydraulic behavior study of two phase critical flow from narrow slits and concerned code validation demanded a lot of instrumentation and safety arrangements to achieve proper control over thermal inertia of the huge setup.