Industry Accomplishment

Fourth advanced US reactor achieves criticality at INL, surpassing White House goal

Over the Independence Day weekend, another major nuclear milestone took place in Idaho. Aalo Atomics’ advanced reactor design, the Aalo-X, successfully completed a zero-power fueled criticality demonstration at the Idaho National Laboratory (INL). The milestone officially surpasses the goal set by President Trump to have three advanced reactors achieve criticality before the United States’ 250th birthday.

Aalo Atomics achieves criticality on July 4

Executive Order 14301 set an ambitious goal for at least three test reactors to achieve criticality by July 4. Two private companies participating in the Department of Energy’s Reactor Pilot Program—Antares and Valar Atomics—reached this stage earlier in June, and Deployable Energy—participating in the DOE's Nuclear Energy Launch Pad—became the third last week. In the last few weeks, reports indicated that Aalo would be next, reaching criticality at Idaho National Laboratory with a low-enriched uranium–fueled, sodium-cooled reactor on or near the target date set forth by President Trump’s EO 14301. In the early hours of July 4, Aalo’s critical test reactor—a full-scale zero-power version of its planned 10-MWe Aalo-X—did just that, becoming the fourth DOE-authorized reactor to hit the milestone.

Deployable Energy achieves criticality at INL ahead of deadline

Deployable Energy’s demonstration microreactor Unity achieved initial criticality at Idaho National Laboratory on June 30 just before midnight. The Department of Energy thus hit its goal of seeing at least three advanced nuclear reactor concepts achieve criticality by the nation’s 250th anniversary.

Department of Energy celebrates fourth criticality ahead of July 4th goal

The U.S. Department of Energy celebrates yet another win for the American nuclear energy renaissance. Early Saturday, as part of the U.S. Department of Energy (DOE) Reactor Pilot Program, Aalo Atomics’ test reactor, Aalo-X, successfully completed a zero-power fueled criticality demonstration. The experiment took place at Idaho National Laboratory and is the fourth DOE-authorized advanced reactor to achieve the criticality milestone, exceeding the July 4th goal outlined by President Trump in his May 2025 executive order.

U.S. Department of Energy meets President Trump’s goals, delivers third advanced reactor criticality

As part of the U.S. Department of Energy (DOE) Nuclear Energy Launch Pad initiative, Deployable Energy’s demonstration reactor, Unity, successfully completed a zero-power fueled criticality demonstration at Idaho National Laboratory. Unity, which achieved criticality late yesterday, is the third DOE-authorized advanced reactor to go critical by the July 4th deadline set by President Trump in his May 2025 executive order. This criticality marks DOE’s fulfillment of a precedent-setting directive to reignite nuclear energy innovation in the United States.

Radiant receives first TRISO fuel shipment at INL’s DOME facility, clearing path to full-power, full-temperature testing

Radiant, a leading developer of advanced nuclear technologies, received its first tranche of nuclear fuel at the National Reactor Innovation Center’s Demonstration of Microreactor Experiments (DOME) facility located at Idaho National Laboratory (INL). The tri-structural ISOtropic (TRISO)-fuel was fabricated by Standard Nuclear in Oak Ridge, Tenn., to Radiant's specifications earlier this year. It will be used to power Radiant’s Kaleidos reactor to conduct a full-power, full-temperature test this summer – kicking-off months of rigorous testing and validation, to support manufacturing and customer delivery by 2028.

Launching into tomorrow: NRIC guides new era of research and deployment

As part of Idaho National Laboratory, NRIC has a variety of test beds, programs, and initiatives designed to take nuclear technologies from concept to commercialization, including the Demonstration of Microreactor Experiments (DOME) test bed, now officially open for business (see p. 44 for more on DOME).

Centrus, Oklo HALEU agreement to support reactor deployment

US enrichment company Centrus is to supply Oklo with high-assay low-enriched uranium to power up to five Aurora powerhouses for multiple years, with deliveries scheduled to begin in 2029.

In a first for advanced nuclear: Siemens Energy turbine package advances for Oklo’s Aurora-INL

The steam turbine and generator package for Oklo’s first Aurora powerhouse at Idaho National Laboratory (INL)—a pioneering application of a commercially established industrial turbine platform at the heart of a first-of-a-kind advanced reactor’s conventional island—is in active production at Siemens Energy’s facilities in Görlitz and Erfurt, Germany.

Department of Energy celebrates second advanced reactor achieving criticality

The U.S. Department of Energy (DOE) celebrated another historic milestone in America’s nuclear renaissance. DOE Reactor Pilot Program participant Valar Atomics’ advanced reactor design, Ward 250, successfully completed a zero-power fueled criticality demonstration. The experiment took place at the Utah San Rafael Energy Lab in Emery County, Utah, and marks the first DOE authorized reactor built outside of a national laboratory.