Abstract: A fuel bundle assembly for a nuclear reactor includes a modified channel and a handle unit that improves pressure drop performance. With the modified channel, one approach is to vary the outside dimension of the fuel channel along the length of the channel, but maintain a constant channel wall thickness. Another approach is to maintain the external dimensions of the fuel channel and vary the wall thickness along the length of the channel. The handle unit is formed including a handle member and a separate rod support member releasably engageable with the handle member. The handle member includes channels for receiving latch pin assemblies, coolant rods and a spacer assembly. The rod support member includes a plurality of fuel rod support chambers providing lateral support for the fuel rods of the fuel assembly. The rod support member also includes a main chamber that is sized to receive a portion of the handle member in a friction fit.

Abstract: A fuel bundle assembly for a nuclear reactor includes a modified channel that improves pressure drop performance and a handle assembly that includes structure for preventing a broken end plug from escaping the fuel bundle. In modifying the channel, one approach is to vary the outside dimension of the fuel channel along the length of the channel, but maintain a constant channel wall thickness. Another approach is to maintain the external dimensions of the fuel channel and vary the wall thickness along the length of the channel. The handle assembly replaces the conventional upper tie plate and is provided with structure for preventing debris such as a broken fuel rod end plug from escaping the fuel bundle. The structure preferably includes a plurality of gridwork cross members forming a substantially square grid including gridwork windows that are sized smaller than the fuel rod end plugs.