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Ameren Missouri’s Callaway Energy Center Begins Routine Refueling and Maintenance
New Reactor Vessel Head to be Installed

Ameren Missouri’s Callaway Energy Center began its 20th planned refueling and maintenance outage Saturday, Oct. 11, and will be out of service for several weeks. Refueling outages at the 1,190-megawatt nuclear facility occur every 18 months. However, planned maintenance work during this particular refuel will be far from routine.

One of the largest maintenance activities in the plant's history will take place  with replacement of the original reactor vessel head installed when Callaway went online in 1984. As a critical replacement, the approximately $150 million part will ensure the continued safe and reliable operation of Callaway, which is recognized as one of the safest and highest performing non-carbon producing generating centers in the United States.

Installation of the new reactor vessel head represents one of several reliability projects by Ameren Missouri, which is focused on transitioning to a cleaner, more diverse energy portfolio in a responsible fashion.

During the refueling, operators will also replace 84 of the 193 fuel assemblies in the reactor core. Each fuel assembly is an 8 ½-inch-square bundle of 12-foot long metal tubes containing ceramic pellets of uranium dioxide fuel. Additionally, thousands of maintenance activities, inspections and tests will be performed to ensure maximum safety and reliability when the plant returns to service.

To help accomplish the wide range of tasks, more than 1,100 supplemental workers will join Callaway’s regular workforce of about 800 employees – providing a powerful boost to the area’s economy.

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 plants. Service to customers will not be affected.


Ameren Missouri has been providing electric and gas service for more than 100 years, and the company's electric rates are among the lowest in the nation. Ameren Missouri's mission is to power the quality of life for its 1.2 million electric and 127,000 natural gas customers in central and eastern Missouri. The company's service area covers 64 counties and more than 500 communities, including the greater St. Louis area. For more information please visit AmerenMissouri.com or follow Ameren Missouri on Facebook or Twitter.

CONTACT: Missouri Communications, 314-554-2182, missouricommunications@ameren.com