Irradiation test device

A recycling line for irradiation test is disposed in a portion of a pressure tube reactor, and it is separated from cooling recycling lines of other pressure tubes to provide a function for controlling chemical properties, pressure, temperature and flow rate of the fluid and a heat recovering function for recovering heat of the fluid of the recycling line. In addition, a portion of other pressure tubes is used for irradiation test. As a result, there can be performed an irradiation test in which chemical properties, pressure, temperature and flow rate of the fluid around the irradiation test specimen are controlled to predetermined values. Further, heat generated from irradiation test specimens contained in the pressure tubes for the irradiation test can be used for the operation of the pressure tube reactor. Then, an irradiation test device with less restriction for the number of irradiation tests to be performed and the dimension of irradiation test specimens can be realized easily by using the pressure tube reactor while satisfying the requirement of controlling the circumstantial conditions which are important in the irradiation test. (N.H.)