The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1992
Filed:
Jan. 12, 1990
Shozo Nakamura, Hitachioota, JP;
Tadashi Mizuno, Kitaibaraki, JP;
Tetsuo Yasuda, Hitachi, JP;
Akira Maru, Toukai, JP;
Yoshishige Kawada, Hitachi, JP;
Yoshihiko Yanagi, Hitachi, JP;
Hiromasa Hirakawa, Hitachi, JP;
Junjiro Nakajima, Hitachi, JP;
Yasuhiro Aizawa, Hitachi, JP;
Yorihide Segawa, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Engineering Co., Ltd., Ibaraki, JP;
Abstract
A nuclear fuel assembly has a plurality of fuel rods and a lower tie plate supporting their lower ends. Coolant apertures extending through the lower tie plate. A channel box surrounds the fuel rods and receives the lower tie plate, to confine the coolant. To restrict leakage of coolant between the tie plate and the channel box, the coolant apertures include, adjacent the periphery of the lower tie plate, a plurality of peripheral apertures which are located at least partly outside the outermost fuel rods. The peripheral apertures each provide a coolant velocity peak located further from the axial center line of the tie plate than the axial center lines of the closest neighboring fuel rods. The invention also provides venturis in the leakage path between the channel box and the tie plate, to restrict deformation of the tie plate.