Spectra thermal fatigue tests under frequency controlled fluid temperature variation; Transient temperature measurement tests

Kawasaki, Nobuchika ; Kubayashi, Sumio; Hasebe, Shinichi; Kasahara, Naoto

The coolant leakage by thermal striping phenomenon should be prevented at nuclear power plants and a lot of efforts are made to develop its evaluation methods. The frequency transfer function method can explain temperature and stress response to fluid temperature history using transfer function models; therefore it is considered as an excellent evaluation method. To measure temperature response of structures to fluid and to confirm their frequency characteristics, transient temperature measurement tests were performed by JAEA. In the transient temperature measurement tests, three different frequencies of sinusoidal fluid temperature waves (0.05, 0.2, 0.5Hz) were controlled using frequency controlled thermal fatigue test equipment (SPECTRA) and temperature responses at inner and outer structural surfaces were measured along the test sections. Frequency effects on temperature attenuation during transfer process from fluid to structures were confirmed and the effective heat transfer function in frequency transfer function method was verified by transient temperature measurement test results.