The Ameren Missouri Callaway Energy Center began its 19th planned refueling and maintenance outage today and will be out of service for several weeks. Refueling outages at the 1,190-megawatt nuclear facility occur every 18 months.
Callaway has operated continuously since its last refueling, which ended in November 2011 – a period of 500 days. It was the facility's second-longest continuous run and marked the third time that Callaway has operated continuously between refuelings – called a breaker-to-breaker run – since opening in 1984. Callaway's all-time record run is 520 days, which ended in October 2008.
During the current refueling, operators will replace 89 of the 193 fuel assemblies in the reactor core. Each fuel assembly is an 8½-inch square bundle of 12-foot metal tubes containing ceramic pellets of uranium dioxide fuel. Additionally, thousands of maintenance activities, inspections and tests will also be performed to ensure maximum safety and reliability when the energy center returns to service.
To help accomplish the wide range of tasks, more than 800 supplemental workers, primarily from Missouri, will join Callaway's workforce of about 800 employees.
The Callaway Energy Center typically generates about 20 percent of the electricity supplied to Ameren Missouri's 1.2 million customers. While the facility is out of service, the energy it normally produces will be replaced by other Ameren Missouri energy centers.