NUCLEAR REACTOR FUEL ASSEMBLY Russian patent published in 2014 - IPC G21C3/00 

FIELD: physics, atomic power.

SUBSTANCE: invention relates to atomic power engineering and specifically to fuel assemblies used primarily in RBMK-1000 reactors, as well as VVER-440 and VVER-1000 reactors. The structure of the fastening of fuel elements in the bearing terminal (support) grid has a cylindrical part made of zirconium alloy E110. Fuel elements are fixed in the support grid by deforming the hollow end of a ferrule simultaneously at three or more points on the perimeter by a defined value, wherein the described diameter of the ferrule increases to value necessary to hold the fuel element in the support grid. The surface of the mounting opening of the support grid is stepped with the length of the step of a larger diameter equal to 0…0.5 times the thickness of the support grid, wherein the surface with a larger diameter can be conical, and at the end of the ferrule of the fuel element there is an opening which is coaxial with its outer surface, with depth of not more than the thickness of the support grid. At 3…4 points, said part of the ferrule is identically deformed such that the outer surface of the ferrule is goes beyond the smaller diameter of the mounting opening.

EFFECT: high reliability of fixing a ferrule of a fuel element in a support grid owing to absence of gaps in the axial and radial directions and preventing rotation of the fuel element about the longitudinal axis.

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