NUCLEAR REACTOR FUEL ASSEMBLY AND METHOD OF ITS MANUFACTURING Russian patent published in 2024 - IPC G21C3/30 

FIELD: nuclear reactors.

SUBSTANCE: invention relates to design and manufacture of fuel assemblies of VVER reactors. Assembly comprises a head, a shank with a filter, a bundle of fuel elements containing nuclear fuel, which are installed in a regular triangular grid in a frame. Frame comprises a bearing grid, a central pipe, guide channels and spacer grids fixed in it, which consist of several groups of straight plates cut in the area of the guide channels, located in one tier and connected to each other by means of transverse slots forming cells. Hexagonal cells have three equal faces alternating along their perimeter, long faces of which are in contact with shells of fuel elements, and on both edges of these faces at points of contact there are ledges for assembly and retention of fuel elements, bent through angle of 1…2 degrees from the axis of the fuel element. At that, in cells, where guide channels and central pipe are located, long faces are removed for installation of these elements into frame. In places of contact of remaining faces of cells with guide channels and central pipe on edges of these faces, plates have local expansions. In the method of making the assembly, spacer grids are made from a sheet by means of laser cutting, and finished fuel elements are automatically installed into the frame by pushing them from the head side into the cells of the plate spacer grids until they stop against the bearing grid.

EFFECT: improving reliability of assemblies for VVER reactors due to reduction of thermomechanical loads on elements of assemblies during manufacture and operation of assemblies.

13 cl, 15 dwg