Removable deflectors for bwr fuel with steam vents and part-length rods

A fuel bundle for boiling water reactors comprising:

• a plurality of vertically aligned, laterally spaced-apart fuel rods within said fuel bundle for generation of a fission reaction in the presence of water moderator;
• a lower tie plate for admitting water moderator through said lower tie plate to the interstices of said fuel rods and supporting said vertically aligned, spaced-apart fuel rods;
• an upper tie plate for enabling water and steam to be discharged from the top of the fuel bundle and maintaining said vertically aligned, spaced-apart fuel rods in upstanding, spaced-apart, side-by-side relation;
• a plurality of spacers vertically spaced from one another between said upper and lower tie plates for maintaining said fuel rods laterally spaced from one another;
• a surrounding fuel channel for confining moderator flow along the fuel rods and from said lower tie plate to said upper tie plate;
• at least one of said fuel rods being a part-length rod extending vertically from the lower tie plate and terminating short of the upper tie plate wherein the upper end of said one part-length rod defines with respect to the surrounding fuel rods a volume overlying said part-length rod under said upper tie plate;
• at least one deflector extending below the upper end of said part-length fuel rod and in substantial vertical registration with said volume for deflecting flow of liquid laterally away from said volume and into the interstices of laterally adjacent fuel rods, enabling reduction in void fraction in said interstices;
• a support for said deflector connected between at least one of said upper tie plate and said spacers for releasably securing said deflector to said fuel bundle enabling access to and removal of said part-length fuel rod through the top of said fuel bundle upon removal of said deflector.

A fuel bundle for boiling water reactors comprising:

• a plurality of vertically aligned, laterally spaced-apart fuel rods within said fuel bundle for generation of a fission reaction in the presence of water moderator;
• a lower tie plate for admitting water moderator through said lower tie plate to the interstices of said fuel rods and supporting said vertically aligned, spaced-apart fuel rods;
• an upper tie plate for enabling water and steam to be discharged from the top of the fuel bundle and maintaining said vertically aligned, spaced-apart fuel rods in upstanding, spaced-apart, side-by-side relation;
• a plurality of spacers vertically spaced from one another between said upper and lower tie plates for maintaining said fuel rods laterally spaced from one another;
• a surrounding fuel channel for confining moderator flow along the fuel rods and from said lower tie plate to said upper tie plate;
• at least one of said fuel rods being a part-length rod extending vertically from the lower tie plate and terminating short of the upper tie plate wherein the upper end of said one part-length rod defines with respect to the surrounding fuel rods a volume overlying said part-length rod under said upper tie plate;
• at least one deflector including an opening for receiving an upper end portion of said one part-length rod whereby said deflector extends below the upper end of said one part-length rod, said deflector being disposed in substantial vertical registration with said volume for deflecting flow of liquid laterally away from said volume and into the interstices of laterally adjacent fuel rods, enabling reduction in void fraction in said interstices;
• a support for said deflector connected between at least one of said upper tie plate and said spacers for releasably securing said deflector to said fuel bundle enabling access to and removal of said part-length fuel rod through the top of said fuel bundle upon removal of said deflector.