METHOD AND DEVICE FOR EDDY-CURRENT INSPECTION FOR GADOLINIUM CONTENT OF EACH PELLET IN URANIUM- GADOLINIUM FUEL PILE OF FUEL ELEMENT Russian patent published in 2003 - IPC

FIELD: nondestructive eddy-current inspection of materials and parts such as fuel elements of nuclear power reactors. SUBSTANCE: proposed method and device mainly designed for dual-frequency eddy-current inspection for gadolinium content in each fuel-element pellet charged with uranium- gadolinium fuel depend for their functioning on comparison of inspection results attained at same sections of fuel element by means of two measuring systems incorporating through-type measuring transducers passing fuel element under check and compensating transducers holding standard specimens; novelty is that first system uses during inspection superposition of external dc magnetic field built up by rare-earth elements based permanent magnets and second one does not use this superposition; gadolinium content in each pellet is calculated by means of computer including noise brought in by ferromagnetic inclusions of pellets, deviations of electric conductivity and geometric dimensions of cans of fuel elements under inspection from those of standard specimens, and also displacement of fuel element axis from those of measuring transducers. EFFECT: enhanced precision of computing gadolinium content in pellets having ferromagnetic inclusions. 8 cl, 4 dwg