Patent Number: 055219500
Section: abstract

A tool set and a method of using those tools in combination is disclosed that are especially well adapted to the function of rearranging and/or replacing the control rods and fuel supports in a boiling water reactor. The tool set includes a grapple that is capable of simultaneously picking up both a control rod and its associated fuel support. A separate unlatching tool is provided for pulling the control rod's release handle in order to decouple the control rod from a control rod drive. A storage rack that may be mounted in the reactor pressure vessel is provided for storing a fuel support and a pair of control rods when the positions of selected control rods are being shifted about the reactor core area. In the method aspect of the invention, the unlatching tool is used to pull the control rod's release handle. Thereafter, the grapple lifts the control rod and its associated fuel support as a unit. When rearranging the positions of the control rods, a first control rod and its associated fuel support are placed the storage rack. Then a second control rod/fuel support assembly is removed in a similar manner and the second control rod is placed in the storage rack. Thereafter, the first control rod may be removed from the storage rack and placed in the position formally occupied by the second control rod with the same fuel support that was removed from the second location.