METHOD FOR DIAGNOSING SUBSTANDARD SPENT FUEL ASSEMBLY OR ITS ELEMENTS Russian patent published in 2024 - IPC G21C19/00 

FIELD: measuring.

SUBSTANCE: invention relates to a method for diagnosing substandard spent fuel assemblies or elements thereof, extracted from a nuclear reactor or storage pool and intended for subsequent storage and processing, and can be used at nuclear power plants or spent nuclear fuel storages. When carrying out diagnostics, the canister with the above assembly or its fragments is preliminarily weighed in order to determine the preliminary assessment of the integrity of the above assembly and preliminary determination of the number of fuel elements. Weight of said assembly or its fragments is calculated taking into account the mass of condensate in the canister, the level and temperature of the condensate in the holding tank of the cassettes, as well as taking into account the geometric dimensions of the canister. Gamma-ray scanning of the active part of the above assembly or its fragments is carried out in order to determine the number of fuel elements in the bundle of fuel elements of the above assembly by rotating the canister with fuel assemblies around its longitudinal axis with determination of the number of possible fuel elements from the number of teeth on the radiation dose rate graph as a function of the angle of rotation at its rotation. Further, during vertical movement of the assembly, the location of its active part or its fragments is determined and a gap is marked between the upper bundle of fuel elements and the lower bundle of fuel elements on the surface of the canister and the state of the outer surface of the canister is visually inspected.

EFFECT: improving reliability of the obtained data during diagnostics of substandard spent fuel assemblies or their elements placed in canisters in the spent fuel pool.

1 cl, 1 dwg