Published July 6, 2026 at 10:58 AM MDT

The Trump administration says it has surpassed a major milestone in nuclear energy.

It wanted to help bring at least three privately-developed nuclear reactors online by the country’s birthday. A fourth went “critical” in the early morning hours of July 4.

Antares was the first company to “go critical,” or turn on its relatively small test reactor. That happened in early June at Idaho National Lab in the eastern part of the state's high desert. Valar Atomics’s reactor joined the ranks a few weeks later at Central Utah’s San Rafael Energy Lab, and Deployable Energy followed.

Now, Aalo Atomics has narrowly met the deadline. The company says it demonstrated a self-sustaining chain reaction within a nuclear fission reactor at 12:20 a.m. on July 4 at Idaho National Lab.

All four companies are part of U.S. Department of Energy’s programs. The agency sped up permitting and construction to help them meet the federal benchmark and help meet rising energy demand.

“We will look back in history and remember this pivot, not just in America's nuclear energy, but in America's energy,” Energy Secretary Chris Wright said in a June 25 Idaho National Lab speech provided by Idaho Falls’ Local News 8. He referred to the event as “nuclear Woodstock.”

Lab Director John Wagner said this is just a first step.

“The goal is 400 gigawatts of nuclear capacity by 2050,” Wagner said. “The goal is energy dominance.”

Though the four companies’ reported that their initial tests were successful, some nuclear safety experts still worry that quick development could lead to mistakes. And while some environmental advocates argue that nuclear energy is cleaner and safer than fossil fuels, others argue the U.S. should instead focus on proven renewable energy technology, such as solar and wind.

The Palo Verde Nuclear Generating Station, about 50 miles west of Phoenix, is the only nuclear power plant in the Mountain West, according to a list from the Nuclear Regulatory Commission.

The majority of the country’s plants are east of the Mississippi River, but the western region is important for the development of new reactors.

This story was produced by the Mountain West News Bureau, a collaboration between Boise State Public Radio, Wyoming Public Media, Nevada Public Radio, KUNR in Nevada, KUNC in Northern Colorado, KANW in New Mexico, Colorado Public Radio and KJZZ in Arizona as well as NPR, with support from affiliate newsrooms across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting and Eric and Wendy Schmidt.