Study on rapid wastage due to liquid droplet impingement on heat transfer tube in SG of fast breeder reactor

Wastage phenomena occur when a heat transfer tube is failed in a Steam Generator (SG) of Fast Breeder Reactor (FBR) and its mechanism is still unexplained. We focused on Liquid Droplet Impingement Erosion (LDIE) as a factor of the wastage phenomena and performed a basic study with a partial mock-up water test simulating a piping group in SG for quantitative evaluation of LDIE. First, we did visualization tests of high pressure and high speed jet into water. The test section consists of a failure heat transfer tube and neighboring sound transfer tubes. Long slit, circular/rectangular holes were used as failure conditions. Upstream pressure and vapor temperature were 0.3 MPa and about 300 K, respectively. Second, we carried out pressure and temperature measurement tests under the same test conditions as described above. We evaluated steam jet behaviors using these two tests results. In addition, we performed numerical simulations of the tests with a multi-phase and multi-component analysis code SERAPHIM. (author)