Patent Number: 056028873
Section: abstract

A tool for pushing a suspended shroud repair tie rod assembly radially inward in the downcomer annulus of a boiling water reactor. The tie rod pusher tool includes a pole adaptor for coupling to the end of a service pole, a pole adaptor extension having one end connected to the pole adaptor, a mounting channel connected to the other end of the pole adaptor extension, a hydraulic spreader mounted on the mounting channel, an adaptor bracket having a proximal end connected to the pivoting member of the hydraulic spreader, a rocker plate pivotably mounted on the distal end of the adaptor bracket, and a saddle mounted on the rocker plate. Using a service pole, the tool is lowered into a position whereat the saddle contacts the tie rod assembly when the hydraulic spreader is actuated. In the open position, the saddle bears against the tie rod assembly with sufficient force to displace the assembly radially inward until the clevis hook clears the clevis pin. Then the tie rod assembly is lowered until the tip of the clevis hook clears the bottom of the clevis pin. During descent of the tie rod assembly, it slides against the saddle of the pusher tool. The saddle is made of ultra-high-molecular weight polyethylene to prevent scratching of the tie rod assembly. When the pressurized fluid to the spreader is cut off, the bottom end of the suspended tie rod assembly drifts radially outward, causing the clevis pin to engage the clevis hook.