Fuel assembly

摘要

A fuel assembly comprises a plurality of fuel rods, moderator rods disposed among the fuel rods, upper and lower tie plates for holding both end portions of the fuel rods and the moderator rods, and fuel spacers for keeping distances between the fuel rods and the moderator rods constant. The fuel assembly is characterized in that there is provided a space region extending from the upper tie plate to the lower tie plate and having a space enough to dispose at least one of the fuel rods. At least one of the moderator rods being disposed adjacent to the space region. The fuel rods, the moderator rods, and the space region are disposed in a grid form.