US 11,721,444 B2
Method for installing extension tube in a nuclear reactor
Anthony J. Mastopietro, Wauwatosa, WI (US); and Eric M. Benacquista, Pittsburgh, PA (US)
Assigned to Westinghouse Electric Company LLC, Cranberry Township, PA (US)
Filed by Westinghouse Electric Company LLC, Cranberry Township, PA (US)
Filed on Jul. 14, 2021, as Appl. No. 17/375,885.
Application 17/375,885 is a division of application No. 16/883,339, filed on May 26, 2020, granted, now 11,380,447.
Prior Publication US 2022/0005616 A1, Jan. 6, 2022
Int. Cl. G21C 13/036 (2006.01); G21C 19/20 (2006.01); G21C 3/32 (2006.01); G21C 3/326 (2006.01); G21C 7/10 (2006.01)
CPC G21C 13/036 (2013.01) [G21C 19/20 (2013.01); G21C 3/3206 (2013.01); G21C 3/326 (2013.01); G21C 7/10 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for installing an extension tube in a nuclear reactor comprising a control rod drive mechanism (CRDM) housing with a threaded head penetration nozzle and a thermal sleeve disposed therein, the method comprising:
removing the thermal sleeve from the threaded head penetration nozzle;
installing the extension tube in lieu of a replacement thermal sleeve, wherein the installing comprises:
aligning the extension tube with a threaded end of the threaded head penetration nozzle, the extension tube comprising a threaded end and non-threaded end, the threaded end sized and configured to threadably couple to the threaded head penetration nozzle;
threading the threaded end of the extension tube to the threaded end of the threaded head penetration nozzle;
torqueing the extension tube to the threaded end of the threaded head penetration nozzle;
gauging the alignment of the extension tube relative to the threaded head penetration nozzle; and
installing retention fillet welds between the extension tube and the threaded end of the threaded head penetration nozzle; and
installing a guide funnel to the non-threaded end of the extension tube.