Results of failure propagation tests in steam generator test facility(SWAT-3); Report No.1

not registered; not registered; not registered; Daigo, Yoshimichi

Failure propagation tests have been carried out using the Steam Generator Safety Test Facility (SWAT-3) in PNC O-arai Engineering Center to establish the method of safety design of the LMFBR Monju's prototype steam generator with reference to preventing sodium-water reaction accidents. The main object of these tests is to understand how the failure propagation to heat transfer tubes around progresses owing to the water leakage from the initial nozzle. Here reported are the data of the first three failure propagation tests conducted in october 1979. Three injection tests (SWAT-3 Run-8 through 10) were executed whose initial water leak rates were 36 g/s, 6.8 g/s and 570 g/s respectively. (1)Failure propagation progressed in about each one minute in Run-8 and 10, but it did not occur in Run-9. (2)The maximum size of penetration holes is about 5.7 mm for water tubes, and is 18 mm 33 mm for gas tubes. (3)The main mechanism of failure seemed to be the wastage. (4)There were some bowing and buldging tubes as well as wastaged tubes in Run-8 and 10. (5)The wastage rate was less than 710 mm/s in accordance with results of intermediate wastage tests.