AKORT-1 on-line system for technological control of the mixed fuel distribution in fuel elements

An on-line system for technological control of experimental fuel elements with vibrocompacted UO2-PuO2 fuel rods fabricated for the BOR-60 reactor is described. Equipment and performance specific features of the system mechanical part and electronic circuits are considered. The results of the system performance testing are given. The fuel element quality sorting is made on the base of the analysis of Pu and fuel density distributions in the rod length. Gamma-absorption method for density measuring and the method of Pu content determination by its own gamma radiation are used in the system simultaneously. The system has the following main characteristics: tested fuel element diameter is 6 mm; the range of fuel rod mean densities is 7-10 g/cm3; Pu content in the fuel is more than 20%; gamma detectors are the NaI(Tl) detectors with dimensions 40x40 and 25x25 mm; energy resolution is < 15% for 137Cs gamma line. Electronic circuits of the system operating on-line with the D3-28 microcomputer are made using the VECTOR standard. The system testing has shown that the error in the fuel density determination is less than 1%, that for Pu content measuring is 4%, the system capacity is 6 fuel elements per hour