- Engineering services
- Project management
SGT LLC, a joint venture company with URS and AREVA NP, played a significant role in the successful replacement of four steam generators at AmerenUE’s Callaway Nuclear Plant near Fulton, Missouri.
Located five miles north of the Missouri River on a plateau 300 feet above the normal 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 and has generated an average of 8.9 billion kilowatt-hours of electricity per year.
Steam generators are used in pressurized water reactor nuclear plants to transfer heat from water heated under pressure inside the reactor to a second, closed-water system that turns the heat to steam that drives the turbine-generator to make electricity. The large size of the generators — 68 feet tall, 17 feet in diameter at their widest part and 372 tons each — made installation in a complex environment challenging.
Technical successes at Callaway included a nearly perfect fit of all four generators to the reactor coolant system, high quality large bore secondary welding, and zero foreign material exclusion issues.
Work was completed in a record-breaking 63 days and 13 hours, besting the record for steam generator replacement outage duration by one day, three hours.
The project 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.