The Callaway plant, a single-unit, 1,126-MW pressurized-water reactor generating station, was completed near Fulton, Mo., in 1984. AmerenUE, St. Louis, plans to replace its four steam generators during the refueling outage scheduled for fall 2005 with a unit fitted with Alloy 690 thermally treated tubes. That change requires replacement of the condenser tubes with stainless steel because the copper-nickel material of the old tubes could cause corrosion in the new tubes.

In May 2003, AmerenUE awarded a contract to Nooter Construction Co., St. Louis, to perform the condenser-tube replacement with tube bundles shop-fabricated by Thermal Engineering Inc., Pittsburgh, Kan. Under a separate contract, Thermal was responsible for design, fabrication and delivery of the bundles to the plant. Utility officials would not disclose project costs.