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. 16, 1991
Filed:
Nov. 07, 1988
Motoo Aoyama, Mito, JP;
Junichi Koyama, Hitachi, JP;
Sadao Uchikawa, Katsuta, JP;
Yasunori Bessho, Mito, JP;
Michihiro Ozawa, Hitachi, JP;
Mitsunari Nakamura, Hitachi, JP;
Akinobu Nakajima, Hitachi, JP;
Hiromi Maruyama, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A fuel assembly has a plurality of first fuel rods each of which contains nuclear fuel material but does not contain burnable poison, and a plurality of second fuel rods each of which includes nuclear fuel material and burnable poison. The amount of burnable poison in a lower region of the fuel assembly is smaller than that in an upper region thereof. When each of the second fuel rods is divided into an upper region and a lower region, a region of the divided regions in the second fuel rods containing a maximum burnable poison concentration Gmax and a region of the divided regions in the second fuel rods containing a minimum burnable poison concentration Gmin are located in the lower region of the fuel assembly. The burnable poison concentration of the upper region of each second fuel rod is between Gmax and Gmin. The fuel assembly may moderate a maximum linear heat rating with an increased spectral shift effect.