ANS's “Powering Our Future: The Coal to Nuclear Opportunity” panel discussion featured (top left, clockwise) Jessica Lovering, Patrick Burke, Kenya Stump, Andrew Griffith, Christine King, and Carol Lane. (ANS screenshot)
Since at least June of last year—when TerraPower and PacifiCorp announced plans to site the Natrium reactor demonstration project at one of Wyoming’s retiring coal plants—the concept of repurposing those plants to host nuclear reactors has been a popular topic of conversation among the energy cognoscenti.
A still image from a three-part video tour of NuScale’s facilities. (Photos: NuScale Power)
NuScale Power has signed a memorandum of understanding with Xcel Energy to explore the feasibility of the utility’s serving as a plant operator at NuScale plants, the Portland, Ore.-based small modular reactor developer announced earlier this week.
Xcel owns and, through subsidiary Northern States Power Company, operates Minnesota’s two nuclear plants, Monticello and Prairie Island. The Monticello facility houses one 671-MWe boiling water reactor, while Prairie Island has twin 550-MWe pressurized water reactors.
Fig. 1. All reactors. The median DER net capacity factor of the 96 reactors included in this survey for the three-year period 2018–2020 is 91.33 percent. For the five three-year periods between 1997 and 2011 shown above, 104 reactors were in operation. The 2012–2014 capacity factor includes 100 reactors, and 2015–2017 includes 99 reactors.
Capacity factor is a measure of reliability, and reliability delivers results. The U.S. nuclear power fleet produced about 789.9 TWh of clean electricity in 2020 and ended the year with 94 operating reactors. According to Energy Information Administration data, that’s about 37 percent more electricity than the 576.9 TWh produced in 1990 by a much larger fleet of 112 reactors.
Nuclear News has tracked and analyzed the capacity factors of the U.S. fleet since the early 1980s, before concerted industry efforts yielded unforeseen performance improvements. High nuclear capacity factors are now less an achievement than an expectation. So much so, in fact, that advanced reactors in development today are assumed to be capable of achieving capacity factors above 90 or even 95 percent.
The U.S. fleet has maintained a median capacity factor near 90 percent for 20 years (see Fig. 1), and the median design electrical rating (DER) net capacity factor for 2018–2020, at 91.33, does not disappoint—unless by showing virtually no change relative to the median of 91.34 recorded in 2015–2017. However, this lack of meaningful difference only underscores the consistent reliability of the U.S. fleet.