Nuclear Plant Modular Condenser Replacement

Barnhart's use of innovative equipment and techniques once again allowed significant reduction in the critical path schedule of a nuclear plant outage.

After nine months of planning, scheduling, and equipment design, it took less than 51 hours for the Barnhart team to remove and replace the tube bundles and water boxes of two condensers. This was no small task, considering:

the original plant schedule allowed only eight days for the entire project, based upon experience.

the condensers were originally built in place and were not intended to be replaced.

the condenser modules had to slide out of the basement from under the steam turbine, raised to grade level, turned in tight quarters between the main transformers and the Turbine Building wall and hauled away under a 131,000 volt back-up transformer feed.

In 20 hours, the Barnhart team removed 4 old waterboxes and half-tube bundles and hauled the contaminated components into storage. In less than 31 hours, the crew placed two new tube bundles weighing nearly 100 tons in the Condenser shell, moved the 4 huge waterboxes into position and attached them to the tube bundles. Before the clock struck 51 hours, the Barnhart team had moved 10 large components in or out of the basement and returned the Condenser back to the utility's project team for weld-up.

It was the third major nuclear outage project for the Barnhart team in less than two years-all three on Critical Path, all three completed and well under desired schedule. With outage time costing well over $1 million per day, Barnhart was selected from a wide group of bidders after the utility considered our track record and schedule innovations. Utilizing a fixed-price contract with a schedule incentive, Barnhart designed and built a wide variety of special devices for moving, lifting and transporting the components within an aggressive schedule.

This winter, the Barnhart team will return to perform the replacement on the Unit II Condenser in tighter quarters with 60' long modules weighing nearly 200 tons each.

Equipment Used in this Project