Fail-free fuel bundle assembly

摘要

A fuel bundle for a nuclear reactor core is provided. The fuel bundle may include a plurality of rods comprised of nuclear fuel rods and/or isotope production rods. Each rod includes a plurality of interconnected rod segments, wherein at least two of the rod segments of at least one rod have different outside diameters. The fuel bundle may additionally include a plurality of rod spacer grids securely retained between axially adjacent, interconnected rod segments. The rod spacer grids interconnected between axially adjacent rod segments form an array of substantially equally spaced rods. The fuel bundle may further include an elongate tubular channel in which the arrayed rods are housed.

主权项

1. A fuel bundle for a nuclear reactor core, said fuel bundle comprising:
a plurality of rods including at least one of fuel rods and isotope production rods, each rod including a plurality of axially adjacent interconnected rod segments with at least a first rod segment and a second rod segment, each of the rod segments having a first end portion, a second end portion, and a central body portion between the first end portion and the second end portion, the central body portion including an internal cavity, the first and second rod segments having different outside diameters; a rod spacer grid securely retained between each pair of axially adjacent interconnected rod segments to form an array of substantially equally spaced rods; and an elongate tubular channel in which the arrayed rods are housed, wherein each of the rod spacer grids includes a plurality of annular disks, at least one of the plurality of annular disks securely retained between the first rod segment and the second rod segment, the at least one annular disk having a top horizontal surface and a bottom horizontal surface, the central body portion of the first rod segment has an outer diameter of D1 and the first end portion of the first rod segment includes a first horizontal surface contacting the bottom horizontal surface of the at least one annular disk, and the first end portion of the first rod segment has a length Y defined as a distance from the first horizontal surface to the central body portion of the first rod segment, the central body portion of the second rod segment has an outer diameter of D2 and the second end portion of the second rod segment includes a second horizontal surface contacting the top horizontal surface of the at least one annular disk, and the second end portion of the second rod segment has a length N defined as a distance from the second horizontal surface to the central body portion of the second rod segment, and length N>length Y and diameter D1>diameter D2.