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:
Aug. 14, 2007
Filed:
Sep. 30, 2003
Masahiko Yamada, Kobe, JP;
Koichi Nunokawa, Kobe, JP;
Masahiko Yamada, Kobe, JP;
Koichi Nunokawa, Kobe, JP;
Mitsubishi Heavy Industries, Ltd., Tokyo, JP;
Abstract
A fuel assembly includes a bottom nozzle set on a lower core plate of a nuclear reactor, a top nozzle with a hold down spring to urge the bottom nozzle against the lower core plate, guide thimbles which guide control rods, having passed through the top nozzle, toward the lower core plate, a dashpot formed on each of the guide thimbles to reduce the fall velocity of a corresponding one of the control rods, a thimble screw which connects each of the guide thimbles to the bottom nozzle, and a drain hole formed to extend through each of the thimble screw. The dashpot has a large-diameter portion with substantially the same diameter as that of each of the guide thimbles. The diameter d of the drain hole falls within a range of 0.04 D<d<0.08 D where D is an inner diameter of the large-diameter portion.