METHOD FOR DETERMINING PARAMETERS OF VOLUMETRIC DISTRIBUTION OF NUCLEAR FUEL IN STACK OF STOPPED URANIUM-GRAPHITE REACTOR Russian patent published in 2024 - IPC G01T1/167 G01T1/169 G21C17/06 

FIELD: volumetric distribution of nuclear fuel.

SUBSTANCE: invention relates to a method for determining the parameters of the volumetric distribution of nuclear fuel in the stack of a stopped uranium-graphite reactor. In order to search for areas with fuel spills, the intensity of thermal and epithermal neutrons in cells in a graphite stack is remotely measured. Determination of the shape and size of the volumetric distribution zone in which fuel spills are detected is carried out by continuous measurements of epithermal neutrons along the height of the cell measurements from the starting cell in eight directions every 45 degrees, for which the cell with the maximum values of the intensity of epithermal neutrons relative to the surrounding cells is selected. By analysing the distributions of epithermal neutrons in cells, the boundaries of the zone are determined in which the intensity values of epithermal neutrons are approximately equal and do not differ by more than 30% from the average value. The graphite stack zone with a uniform distribution of the epithermal neutron field is described by an equivalent cylindrical volume, and the nuclear fuel distribution parameters are calculated.

EFFECT: ability to remotely determine the location, size and mass of the volumetric distribution of nuclear fuel in a stack of spills of fuel fragments in reactor cells, which makes it possible to assess nuclear safety.

1 cl, 7 dwg