LONDONDERRY TOWNSHIP, PA (Oct. 26, 2009) Exelon Nuclear's Three Mile Island Generating Station Unit 1 today broke the world record for longest continuous days of operation among all pressurized water reactors in the world when operators shut the plant down for a scheduled refueling outage.
The 870-megawatt plant operated for 705 days when it shut down for a scheduled refueling and maintenance outage earlier today. That beats the existing record of 692 days set earlier this year by the Calvert Cliffs Nuclear Power Plant located in Maryland. There are more than 200 pressurized water reactors worldwide.
Operators shut down the unit today to refuel the reactor, perform maintenance on the plant and replace both steam generators. Workers will complete more than 25,000 separate operational, maintenance and testing activities during the outage, including replacing the unit's two steam generators.
The world record among all types of light water reactors is held by another Exelon plant, LaSalle Generating Station Unit 1 in Illinois, which operated for 739 continuous days.
TMI Unit 1 ran continuously since it started up from its last refueling outage on Nov. 21, 2007. The plant generates enough carbon-free electricity for 800,000 homes. Operating continuously from one scheduled refueling outage to another is known in the industry as a breaker-to-breaker run. Uninterrupted operation is an indicator of high levels of operational excellence and equipment reliability.
"Three Mile Island's achievement is a reflection of the company's dedication to the safe and reliable operation of our plants," said Joe Grimes, senior vice president, mid-Atlantic operations for Exelon Nuclear. "Our focus is on human performance and equipment reliability. One outcome is record operating runs such as this one."
Three Mile Island has a track record of reliable operations - four times prior to this the plant set a world record for continuous days of operations.
"We come to work every day with safe and reliable operations as our primary goal," said William Noll, TMI site vice president. "TMI-1's world-class performance is a tribute to the skill, dedication and teamwork displayed by the people who work here."