SGT LLC, an AECOM/AREVA company, played a significant role in successfully replacing four steam generators at AmerenUE’s Callaway Nuclear Plant, located near Fulton, Missouri. Work was completed in, at that time, a record-breaking 63 days and 13 hours, besting the prior record for any previous steam generator replacement outage duration by one day, three hours. This project also set world records for steam generator replacement contractor window duration of 32.7 days and a world record for reactor coolant system cut-to-fill duration of 31.6 days for a four loop Westinghouse unit.
Located five miles north of the Missouri River on a plateau 300 feet above the normal Missouri River level, the plant is a Standardized Nuclear Unit Power Plant System, using a Westinghouse four-loop pressurized water reactor and a General Electric turbine-generator. The plant began service December 1984; by replacing decades-old technology with better performing, more efficient equipment, the plant owners ensure that their customers have a reliable supply of electricity for many years to come.
SGT performed the engineering services required to remove four old steam generators and install four new high efficiency steam generators. The large size of the generators—68 feet tall, 17 feet in diameter at their widest part, and 372 tons each—made installation challenging. Technical successes at Callaway included the close to perfect fit of all four generators to the reactor coolant system, high quality large bore secondary welding, and zero foreign material exclusion issues.