Out-of-Pile Heat Transfer Test Device for Low Pressure Irradiation Capsule

In-pile irradiation capsules are used for fuel and material irradiation at research reactor. Design of irradiation capsule should be based on thermal analysis to determine the key structural parameters. A set of out-of-pile heat transfer test device is innovated for the design validation. Heat transfer performance of in-pile irradiation capsule can be simulated, which includes heat conduction, convection and radiation. Electric heating rod is used as the heat source for the device, which simulates linear power or heat flux of in-pile irradiation capsule. Temperature different of internal components is simulated by adjusting helium gap. Thermocouples are fixed to measure wall temperature and internal temperature of the components in the device. Some out-of-pile heat transfer tests have been carried out for irradiation capsule development for China Advanced Research Reactor (CARR) and China Experimental Fast Reactor (CEFR) at China Institute of Atomic Energy (CIAE). The test verifies surface and internal temperature of the capsules and conclusions of thermal analysis. A finished in-pile test verifies the capsule design at rated power, which also proves that results of the out-of-pile heat transfer test are conservative. The article describes the function, structure, test process and other aspects of the technical requirements of the heat transfer test device.