METHOD FOR MONITORING HELIUM CONCENTRATION IN FUEL ELEMENTS Russian patent published in 2024 - IPC G21C17/06 

FIELD: nuclear energy.

SUBSTANCE: invention can be used in the manufacture of fuel elements at the stage of monitoring helium concentrations in them, in particular, in conditions of conveyor production of fuel elements. The method for monitoring the concentration of helium in a fuel element is based on the excitation of ultrasonic resonant oscillations of the gas column inside the gas cavity of the fuel element, recording and analysing the frequency characteristics of the fuel element. When monitoring fuel rods in the fuel column area, they are mounted horizontally on two supports, one of which is mechanically connected to the output of the ultrasonic emitter, and the other to the input of the ultrasonic receiver, and the amplitude-frequency response (AFR) of the fuel rod is measured in the range of 50÷350 kHz. Fuel rod is successively rotated twice around the longitudinal axis by 120° while reading the frequency response, after which the frequency response is averaged over the three obtained values. By changing the amplitude in the control frequency values corresponding to the resonances of the fuel pellets, relative to the results obtained in the reference samples with a known helium concentration, the helium concentration in the controlled fuel element is determined.

EFFECT: improved accuracy of measuring helium concentration in a fuel element.

2 cl, 4 dwg