TEMPERATURE CONTROL TYPE MATERIAL IRRADIATION DEVICE

PURPOSE:To provide a temperature control type material irradiation device to maintain the radiation temperature of an irradiation sample set in a reactor core at a constant level at the time of variation of reactor core output. CONSTITUTION:This is constituted of an inner cylindrical pipe 6 furnished with a piping to let sodium flow in and out of the piping by way holding an irradiation sample 7 and an outer cylindrical pipe 4 furnished with a piping storing the inner cylindrical pipe 6 with a gas gap 5 and to let cooling gas filled in the gas gap 5 flow in and out of the piping, and the coefficient of thermal expansion of the material of the inner cylindrical pipe 6 is made larger than that of the outer cylindrical pipe 4. As temperature change of the gas gap 5 controls refrigeration and compensates temperature change of the irradiation sample 7 at the time of variation of reactor core output, it is possible to maintain the temperature of a constantly irradiated sample to a roughly constant level without any time lag.