Experimental study on pressure loss in coated-particle-type fuel assembly of gas-cooled fast reactor

Revealing thermal-hydraulic characteristics in coated-particle fuel and fuel compartment regions of a fuel assembly is necessary for a design study of helium-gas-cooled fast reactors which is being performed at JNC as part of the feasibility studies on the commercialized fast reactor cycle system. This report describes a series of experiment to obtain basic data of pressure loss in particle layers and several porous materials simulating those of the fuel assembly as the first step of the investigation. A pressure loss measurement system was designed and manufactured in which the working fluid was dried nitrogen gas. Packed particle beds consisting of glass particles or lead ones were set to the test section of the system to get the basic pressure loss data of the coated-particle fuel region. Sintered metallic (bronze), laminated and perforated panels, and fibrous materials (wood, felt) were selected as the candidate structures of the fuel compartment region. These measurement were carried out under the several pressure levels (1 MPa-7 MPa). From the result of the measurement experiment, it was confirmed that Ergun's correlation equation related to packed beds gives appropriate pressure loss estimation of the coated-particle fuel region under the rated pressure condition and depressurized one and that modified Ergun's equation is applicable to the pressure loss of the sintered metallic. (author)