Abstract: An unlatching tool which can be used to uncouple and grapple standard handle and extended handle control rods from their associated control rod drives. The unlatching tool is lowered onto the handle of a control rod residing in the reactor core. Due to differences in the shapes of the handles of the standard handle and extended handle control rods, the tool is able to sense the type of control rod present and, through the use of a pneumatically actuated cylinder, position the unlatching mechanism at the appropriate elevation. In particular, a four-way valve, that is actuated by contact with the top corner of the handle of the extended handle control rod and is not contacted by the handle of the standard handle control rod, is used to differentiate between control rod types. The unlatching mechanism is positioned relative to the unlocking handle on the control rod using a pneumatic cylinder activated by the four-way valve.

Abstract: An improved tool for removing the highly contaminated inner filter from a control rod drive during a maintenance operation. The tool may also be used to install the inner filter by pushing the inner filter on and locking the spring clip onto flats of the center lug of the control rod drive stop piston. The tool has a collet with flexible fingers which are inserted inside the inner filter while flexed radially inward. After the collet is inserted, a retractable cam with a conical bearing surface is retracted to a position whereat it urges the collet fingers radially outward to clamp the collet onto the inner filter. The locked filter must be rotated before removal. With the inner filter coupled to the collet, the tool is then pulled out to remove the inner filter from the control rod drive.