Patent Number: 041586000
Section: summary

BACKGROUND OF THE INVENTION This invention relates to apparatus for handling control rod drives, and more particularly it deals with apparatus for handling control drives which facilitates removal of control rod drives from a reactor pressure vessel and mounting of the same therein. Heretofore, in a boiling-water reactor, great difficulty has been encountered in effecting maintenance and inspection of control rod drives (CRD's) mounted in a manner to be located below a reactor pressure vessel. That is, in carrying out this operation, the CRD's must be removed from the reactor pressure vessel by performing an operation in a region of high radiation level. It has hitherto been common practice to perform this operation manually by operators who put on protective clothing. It takes a lot of labor and time to perform this operation. Moreover, there is the hazard of the operators being exposed to a high level of radiation. Thus, there has been an increased demand for the development of apparatus permitting maintenance and inspection of each CRD to be carried out automatically without requiring manual attention. SUMMARY OF THE INVENTION Accordingly, this invention has as its object the provision of apparatus for handling CRD's which eliminates the disadvantages of the prior art and enables maintenance and inspection of each CRD to be effected readily and positively. According to the invention, there is provided apparatus for handling CRD's attached by detachable fixing means to housings mounted in a reactor pressure vessel and each coupled to one of control rods inserted in the reactor pressure vessel, such apparatus comprising cylindrical housing means, uncoupling means arranged in the housing means for uncoupling each of the control rods from the respective CRD, means mounted on the housing means for effecting attaching and detaching of the fixing means, and means for moving the support means longitudinally of the CRD. In a preferred embodiment of this invention, the uncoupling means of the apparatus for handling each CRD further comprises means for detachably connecting the uncoupling means to the CRD. In this embodiment, the housing means is rotatably supported on the support means, and the support means is provided with means for driving the support means and causing same to rotate. This embodiment further comprises means for preventing release to outside of coolant from the CRD housing when the fixing means is detached, and drain means for leading the coolant flowing out of the CRD housings to a predetermined position for disposal.