Nuclear Power: Feedwater Heater Removal and Replacement

NUCLEAR POWER:
Feedwater Heater Removal and Replacement
Barnhart was hired to remove three feedwater heaters (FWHs). The heaters were placed in two separate rows inside containment cells. The cells were arranged such that there was limited area for staging of both the old and new FWHs in the auxiliary and turbine hall bays. As the old heaters came out, new heaters had to be sequenced to let the welding contractor tie in the heaters within the same 22-day critical path schedule.

Each line of the FWHs had to be removed from its cell using a floor-mounted rail and steel plate system. Then the newly designed Barnhart powered saddles rolled the vessels to a location directly below a hatchway leading to the auxiliary bay floor above. The
53-ton auxiliary by overhead crane provided the hook to lift the FWH from the saddles (assisted by a tailing 37.5-ton chain hoist) at an angle of approximately 45 degrees and into the auxiliary bay. Once the heaters had cleared the opening, they were placed onto a transfer cart for the subsequent Goldhofer loadout.

The team swapped all six FWHs and completed the project safely within the critical path time allowed! As the old heaters came out, new heaters had to be sequenced to let the welding contractor tie in the heaters within the same 22-day critical path schedule.