Experimental Study on Properties of High Cycle Thermal Fatigue (2) -Results of the temperature Measurement Test-

not registered; not registered; Tanaka, Hiroshi*; lbaraki, Koichi*; Fukasaku, Hiroshi*

At a nuclear power plant, where fluids of high and low temperature flow into each other, it is necessary to prevent structural failure damage caused by the high cycle thermal fatigue (thermal striping phenomenon). The Sodium Temperature Controlled Thermal Fatigue Test Equipment (SPECTRA) was developed by modifying the Thermal Transient Test Facility for Structure (TTS) in order to clarify the effect of temperature fluctuation induced by the thermal striping phenomenon on the crack initiation and its propagation behavior. As two electromagnet pumps mix sodium flows both temperature of 600deg-C and 250deg-C, SPECTRA is able to provide the sinusoidal fluctuation of sodium temperature in the specimen which is made as 66.9mm in inner diameter, 11.1mm in thickness and 1600mm in length. The temperature measurement test by stainless steel was carried out using SPECTRA, and the following results were confirmed: (1)Temperature fluctuation periods of 2-20 seconds of sodium can be induced stably for a long term under the conditions of the mean temperature of 425deg-C and the difference of 200deg-C. (2)The sinusoidal temperature fluctuation range is reduced linearly with the axial direction of specimen. (3)Transmission characteristics of the fluctuation amplitude in the specimen's wall are corresponded to known equations for thermal transmission. (4)It can control the temperature fluctuation as superimpose both short and long periods. After this, sinusoidal temperature fluctuation tests for the stainless steel specimen are going to be carried out based on obtained results.