Nuclear Energy at Callaway
Callaway Energy Center Milestones
March 6, 2015 - Callaway's operating license was renewed by the Nuclear Regulatory Commission, extending it's life by 20 years to the year 2044.
2014 - Callaway completes replacement of the original reactor vessel head which was installed when Callaway originally came online in 1984. The replacement will ensure the continued safe operations of Callaway and is a significant investment to improve reliability and provide cleaner energy for our customers.
2011 - Callaway operated continuously for 489 days, achieving what is known in the industry as a "breaker-to-breaker" run - which means it operated from one refueling to the next without ever being out of service. This marked Callaway's second breaker-to-breaker run since it began operating in 1984 - the first coming in 2008 (520 days). Callaway is one of only 26 of the nation's 104 nuclear plants to achieve a breaker-to-breaker run.
Dec. 19, 2009 - Callaway celebrates 25 years of safe and reliable operation. 2009 also marks the most electricity generated by the station in a calendar year.
2008/2009 - Callaway becomes an industry leader by replacing the carbon steel piping in the Essential Service Water (ESW) system with more durable plastic high-density polyethylene (HDPE) piping. The project marks the first time for HDPE use in an American Society of Mechanical Engineers (ASME) safety-related system in the United States. Callaway also received a Top Industry Practices (TIP) award for the project.
Fall 2008 - Callaway completes first ever sub 30-day refueling outage by wrapping up Refuel 16 in 27.9 days. The facility must refuel every 18 months and continues to execute outages with greater efficiency.
Oct. 20, 2008 - Callaway completes first ever "breaker to breaker" run. The facility remained online for all 520 days of cycle 16. Only a handful of the nation's 104 nuclear plants have accomplished this milestone.
2006 - Callaway receives the prestigious Edison Electric Institute Safety Achievement Award for outstanding worker safety.
Summer/Fall 2005 - Callaway replaces all four steam generators. Each steam generator is about 70 feet long and 17 feet in diameter at its widest point and weighs 360 tons.
May 2, 1996 - Callaway's lifetime power generation reaches 100 billion kilowatthours. At that time, only 28 nuclear energy centers in the U.S. had achieved that mark, and Callaway reached it more quickly than any other energy center.
Summer 1993 - Callaway operates at full capacity throughout the "Flood of '93," helping to ensure an adequate power supply to Ameren customers, while high water interrupts fuel delivery to the company's coal-fired energy centers.
Dec. 31, 1989 - Callaway completes its fifth year of service, having generated more electricity during that period than any other nuclear plant in the United States. Callaway is also the only U.S. nuclear plant to rank among the top ten nuclear plants in the world in total power production.
Apr. 18, 1986 - Callaway completes its first refueling outage (refuelings occur every 18 months).
Dec.19, 1984 - Required testing completed - Callaway declared fully operational.
Oct. 18, 1984 - “Full power” operating license issued by the Nuclear Regulatory Commission (NRC).
|Oct. 2, 1984 - Callaway’s first nuclear chain reaction takes place.
June 13, 1984 - Initial fuel load.
June 11, 1984 - “Low power” operating license issued by the NRC.
Nov. 16, 1982 - Initial fuel delivery.
Oct. 19, 1979 - Application made to the NRC for Callaway's operating permit.
Apr. 16, 1976 - Construction permit granted by the NRC.
Aug. 14, 1975 - Limited Work Authorization granted by the U.S. Nuclear Regulatory Commission (NRC).
Apr. 1, 1975 - Certificate of Convenience and Need granted by the Missouri Public Service Commission.
July 16, 1973 - Project announced and site selected.
How Nuclear Energy Works at Callaway
The heat produced by the splitting (fissioning) of uranium atoms turns water into steam. The steam pressure spins a series of windmill-like devices called turbines, which are connected to an electric generator that produces electricity. Using the diagram below as a reference, here in more detail is how the process works at Callaway Energy Center:
When an atom splits, or “fissions,” it releases energy in the form of heat. It also releases neutrons, which go on to fission other atoms, creating more heat and releasing more neutrons. This continuing activity is called a nuclear chain reaction.
Inside the nuclear reactor vessel, the controlled fissioning of uranium atoms heats water that is pumped through the reactor. Although this water reaches an average temperature of 588 degrees Fahrenheit (309 degrees Celsius), it doesn’t boil, because it is kept under high pressure (2,235 p.s.i.g.).
This hot water from the reactor vessel is pumped through four large heat exchangers called steam generators (only one is shown in the diagram) where the heat is transferred to a second, separate water system.
The water in the second (secondary) system is under less pressure, so the heat causes it to turn to steam. This steam then flows to the turbines. Meanwhile, the water in the first (primary) system returns to the reactor vessel to be reheated and repeat the process.
When the steam reaches the turbines, the steam pressure against the turbine blades causes the turbine shaft to spin. Attached to the shaft is a rotor that turns inside the generator. The turning motion of the rotor - a large electromagnet - inside the stationary coils of wire (stator) of the generator produces electricity.
This electricity is then boosted in voltage by a transformer and carried from the plant on high-voltage lines that connect to the Ameren transmission system.
After the steam in the secondary system passes through the turbine blades, it goes into the condensers, located below the turbines, where it passes over thousands of tubes carrying cooling water from the cooling tower. This cooling water absorbs heat from the steam, causing the steam to condense back into water, which is then pumped back to the steam generators to be reheated and start the steam cycle over.
The cooling water from the condensers flows back out to the cooling tower where the heat it has removed from the steam is released to the air. Except for some water lost out the top of the cooling tower through evaporation, most returns to the condensers again to repeat the cooling process. The water lost through evaporation is replaced with water from the Missouri River.