Patent Number: 051026147
Section: claims

1. A method for underwater welding of a control rod drive housing inserted through a stub tube to maintain requisite alignment and elevation of the top of the control rod drive housing to an overlying and corresponding aperture in a core plate as measured by an alignment device which determines the relative elevation and angularity with respect to the aperture, comprising the steps of: providing a welding cylinder dependent from the alignment device such that the elevation of the top of the welding cylinder is in a fixed relationship to the alignment device and is gas-proof;  pressurizing the welding cylinder with inert welding gas sufficient to maintain the interior of the welding cylinder dry;  lowering the welding cylinder through said aperture in said core plate by depending said cylinder with respect to said alignment device, said lowering including lowering through and adjusting the elevation relationship of the welding cylinder to the alignment device such that when the alignment device is in position to measure the elevation and angularity of the new control rod drive housing, the lower distal end of the welding cylinder extends below the upper periphery of the stub tube where welding is to occur;  inserting a new control rod drive housing through the stub tube and positioning the control rod drive housing to a predetermined relationship to the anticipated final position of the control rod drive housing;  providing welding implements transversely rotatably mounted interior of the welding cylinder relative to said alignment device such that the welding implements may be accurately positioned for dispensing weldment around the periphery of the top of the stub tube and at the side of the control rod drive housing;  measuring the elevation and angularity of said control rod drive housing; and  dispensing weldment along the top of the stub tube and at the side of the control rod drive housing.  monitoring the elevation and angularity of the top of the control rod drive housing during said dispensing step. 2. The process of claim 1 and including the step of