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.

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.

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.

Paul Browning, Mitsubishi Power, and Paul Hinnenkamp, Entergy, sign the joint agreement on September 23. Photo: Entergy

New Orleans–based Entergy Corporation last week announced a commitment to achieve net-zero carbon emissions by 2050, joining a growing list of major energy companies to make that promise—including Dominion Energy, Duke Energy, Southern Company, Xcel Energy, and Public Service Enterprise Group. And, like those companies, Entergy says that it sees nuclear playing an important role in the realization of that goal.

This year’s Utility Working Conference, held on August 11, had a dynamic opening plenary and a packed roster of informative sessions. Following are recaps of some of the 12:00 p.m. (EDT) sessions that took place.

You can read about the UWC's opening plenary here.

Look for more meeting recaps later today.