Fuel assembly
AssigneesHitachi, Ltd., Hitachi Engineering Co., Ltd.
InventorsToshiro Yoshioka, Takao Igarashi, Takaaki Mochida, Michihiro Ozawa
Life of this patent
Estimating the term…
Abstract
A fuel assembly including a channel box, upper and lower tie plates, fuel rods inserted in the channel box and held at upper and lower end portions by the upper and lower tie plates, a water rod disposed among the fuel rods and spacers for keeping the fuel rods and the water rod spaced from one another. The water rod has a diameter larger than that of each of the fuel rods and the upper end of the water rod has a height substantially as high as an upper end of an effective enriched fuel section of each fuel rod.
Claims14
A fuel assembly comprising:
- upper and lower tie plates disposed so as to be spaced from each other;
- a plurality of fuel rods both end portions of each of which is held by said upper and lower tie plates;
- a plurality of spacers disposed between said upper and lower tie plates for providing spacings between said fuel rods;
- a water rod disposed among said fuel rods and held at its lower end portion by said lower tie plate, said water rod having holes for passing water therethrough at its side portion, and a closed upper end portion of said water rod being substantially as high as an upper end of an effective enriched fuel section, which is filled with enriched fuel, of said each fuel rod;
- and
- a channel box enclosing said fuel rods and said water rod, said upper and lower tie plates being fitted in said channel box;
- wherein said water rod has a larger diameter than that of each of said fuel rods, and is disposed among said fuel rods so as to be positioned at a substantially central portion of said fuel assembly.
A fuel assembly comprising:
- a channel box elongated axially;
- upper and lower tie plates mounted in upper and lower end portions of said channel box;
- fuel rods disposed in said channel box and held by said upper and lower tie plates at upper and lower ends of said fuel rods, respectively;
- a large diameter central water rod disposed among said fuel rods around an axis of said channel box, and having a larger diameter than said each fuel rod, said large diameter central water rod having a closed upper end portion, and having holes for passing water at upper and lower side portions, and having a lower end plug held by said lower tie plate, and the upper end portion of said large diameter central water rod being substantially as high as an upper end of an effective enriched fuel section of said each fuel rod;
- and
- spacers, disposed between said upper and lower tie plates, for keeping said fuel rods and said large diameter central water rod spaced from one another.
A fuel assembly comprising:
- upper and lower tie plates;
- a plurality of fuel rods each held by said upper and lower tie plates at upper and lower ends of said fuel rods, respectively, each of said fuel rods including an effective enriched fuel section and a plenum section thereon;
- a plurality of spacers arranged axially for keeping said fuel rods spaced from each other;
- and
- a large diameter central water rod, disposed among said fuel rods so as to be positioned at a central portion of said fuel rods, and having a larger diameter than said each fuel rod;
- said large diameter central water rod having a lower end plug held by said lower tie plate and an upper closed end spaced from said upper tie plate so as to not engage said upper tie plate, said large diameter central water rod having holes for passing water therethrough proximate to the upper and lower ends thereof, said large diameter central water rod having a height at the upper end substantially as high as an upper end of said effective enriched fuel section of said each fuel rod which is filled with enriched fuel pellets.
Dependencies are inferred from the claim text.