Test results of Run-7 in steam generator safety test facility (SWAT-3); Report No.12; Large leak sodium-water reaction test

Hiroi, Hiroshi*; not registered; Daigo, Yoshimichi; not registered

Large leak sodium-water reaction tests have been carried out using the SWAT-3 facility in PNC O-arai Engineering Center to obtain data on the safe design of the prototype LMFBR Monju's steam generator with reference to preventing large leak accident. This report gives the results of SWAT-3 run-7 test. The heat transfer tube bundle of the evaporator used in Run-7 test was designed and manufactured by TOSHIBA/IHI. Main purpose of this test is to clarify the sodium-water reaction phenomena occured in the downcommer region. Water was injected into the evaporator at the rate of 10.6 kg/sec, which corresponds to a test scale of 2 tube failure in an actural size system according to iso-velocity modeling. Measurements were taken of pressure, strain, temperature, sodium level, void, thrust load, acceleration, displacement, flow rate, and so on. Initial spike pressure was 19.5 kg/cma closest to the injection point, and the maximum quasi-steady pressure in the evaporator was 5.8 kg/cma. The rupture disc of the evaporator burst 0.613 sec. after water was injected, and the pressure relief system functioned well. No secondary tube failure was observed.