Feedwater Heater Replacement
During a refueling outage at an Arkansas nuclear plant, Barnhart used a large part of its toolbox to remove and replace two FWH vessels and bundles. The team first off-loaded all the replacement components from rail using mobile cranes and pull-up gantries. Next, the Barnhart team began extracting the bundles from their shells. The plan called for a slide system to double as support frames. The frames were then loaded onto 4-axle floats using pull-up gantries. Barnhart also constructed a 3-leg gantry system to span a 14í deep pit next to the building. Components of the Modular Lift Tower were placed in the pit to support barge ramps under the gantry. To extract the bundle, one end of the frame was connected to the condenser wall while the 125K hoist supported the frame. The bundles were extracted using slide system components and custom chocks for support. Once the bundle was completely extracted, the slide track frame was uncoupled from the condenser wall and turned 90 degrees using the 125K hoist, gantry and slide system. When the bundles were over the pit they were placed on 4-axle floats on top of the barge ramps. The reverse process was used to install the new bundles.
The vessels were removed by installing temporary saddles to jack the vessel from its bases. The vessel was then moved to the floor opening above using the light slide system. Next, Barnhartís innovative Tipstick was used to lift the vessels to the turbine deck and down onto the floats. Next, because the overhead crane main hook would not travel to the center line of the floor opening, the Tri-block system to allow access to the floor opening. The reverse process was used to install the new vessels.