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:
Nov. 22, 1994
Filed:
Jun. 22, 1993
Kazuki Hida, Kawasaki, JP;
Yasushi Hirano, Kawasaki, JP;
Koji Hirukawa, Yokohama, JP;
Tsuyoshi Nakajima, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A fuel assembly for a boiling water reactor comprising an upper and lower tie plates, a plurality of fuel rods filled therein with a plurality of fuel pellets, a fuel bundle comprising the fuel rods retained with a plurality of spacers in spaced relation and disposed between the upper and lower tie plates, and a polygonal tube-like channel box which encloses the fuel bundle and constitutes flow paths for coolant. The fuel rods comprise long fuel rods and short fuel rods which are each shorter in the effective portion than each of the long fuel rods. The concentration of fissile material in each of the short fuel rods is lower than the mean concentration of fissile material in the cross section of the fuel bundle. In the case the fuel bundle is vertically subdivided into two regions, an upper and lower one, with the upper end of the effective portion of each of the short fuel rods as a border, the mean concentration of fissile material in the cross section of the fuel bundle in the region lower than the border is lower than that in the cross section of the fuel bundle in the region above the border.