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. 28, 2000
Filed:
Aug. 11, 1998
Applicant:
Inventors:
Assignee:
Mitsubishi Heavy Industries, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G21C / ;
U.S. Cl.
CPC ...
376364 ; 376434 ; 376438 ; 376442 ; 376446 ;
Abstract
An upper hold-down spring structure for a nuclear reactor fuel assembly. A hold down spring 20 mounted on an upper surface of an upper nozzle 11 of a fuel assembly for a pressurized water reactor is composed of an upper plate spring 21 having plastic spring characteristics and a lower plate spring 23, base ends of which are fixed with a fastening bolt 18 at a common position. The upper spring 21 and the lower spring 23 are made of precipitation hardened nickel base alloy and the thickness of the springs are determined so as to keep the stresses generated less sensitive to stress corrosion cracking.