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. 04, 1995
Filed:
Oct. 25, 1993
Applicant:
Inventors:
Assignee:
ABB Reaktor GmbH, Mannheim, DE;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G21C / ;
U.S. Cl.
CPC ...
376260 ; 2940208 ; 29446 ;
Abstract
After some time incipient cracks may occur in nozzles welded directly into a reactor pressure vessel cover for guiding a control rod, which make it necessary to exchange the nozzles. A method is provided for exchanging the nozzles which changes the structure of the cover little during removal and accomplishes low-stress installation. According to the method, the nozzles are installed with prestressing. An annular surface is introduced from the inside of the cover coaxially to the through-bore and a supporting surface is introduced from the outside of the cover, which surfaces serve for applying the prestressing force and arresting the same.