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:
Dec. 21, 1993
Filed:
Nov. 24, 1992
Mitsubishi Nuclear Fuel Co., Tokyo, JP;
Abstract
A key member, a method for insertion and/or removal of the fuel rods in a nuclear fuel assembly using the key member and a method of disassembling the nuclear fuel assembly using the same key member are disclosed. The key member has first projections and second projections formed on the opposite faces of an elongated key body. In the insertion or removal of the fuel rods or in the disassembling the nuclear fuel assembly, the key member is inserted into the grid and rotated to bring the first projections and the second projections into engagement with the straps of the grids and the springs on the straps to thereby deflect the springs in a direction away from the dimples opposing the springs. In this situation, the insertion and removal of the fuel rods can be carried out. Further, in disassembling the nuclear fuel assembly, space required for inserting the key member into the grids may be ensured by subjecting prescribed portions of control rod-guide pipes and instrumentation pipes to cutting work and bulging the cut ends to move the cut end away from that of the opposing cut ends of the cut piece. The space may be formed by removing the control rod-guide pipes and instrumentation pipes after having formed slits in the pipes.