Wastage tests on Monju superheater tubu material SUS321

not registered; not registered; Kuroha, Mitsuo

It is essential to clarify wastage behavior of a heat transfer tube in a sodium-water reaction in order to analyze a water leakage incident in a steam generator of LMFBR Monju. There fore wastage tests in small and intermediate leak ranges were conducted for austenitic stainless steel JIS SUS321 of a Monju superheater tube material by use of Small Leak Sodium-Water Reaction Test Loop (SWAT-2) and Large Leak Sodiam-Water Reaction Test Rig (SWAT-1). In the tests, a water leak rate, a distance from a leak nozzle to a target tube, and a sodium temperature were varied as empirical parameters. Test Results are as follows: (1)In the small 1eak range (0.110g/sec), the wastage rate of SUS321 depends on L/D and has maximum value at L/D of 20 to 30 ; where L ls distance from the nozzle to the target and D is a nozzle diameter. Since the maximun wastage rate of SUS321 is about half as high as that of SUS304, SUS321 is more resistive against wastage than SUS304. (2)In the intermediate leak range (30 and 150 g/sec), the wastage rate depends on L/D and has a peak at L/D of 2050. The maximum wastage rate is quarter as high as that of 2%Cr-1Mo Steel. (3)Empirical formulas were derived from these test results concerning the relation between the wastage rate and the parameters.