Industry Accomplishment

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.

Deployable Energy receives final safety approval ahead of criticality

Deployable Energy announced approval of its Documented Safety Analysis (DSA) by the U.S. Department of Energy earlier this month, representing another regulatory milestone before proceeding to criticality.

Oklo secures DOE PDSA approval

Oklo announced that the Department of Energy’s Idaho Operations Office had approved the preliminary documented safety analysis (PDSA) for the company’s first deployment of its Aurora Powerhouse, which is currently under construction at Idaho National Laboratory.

Idaho National Lab’s historic milestone: Antares R1 Mark-0 reactor project breaks ground of 50-year legacy

For the first time in nearly 50 years, the laboratory is moving toward the deployment of a new reactor project, the Antares R1 Mark-0. It is a moment that forces us to reconcile the ghosts of mid-century nuclear ambition with the urgent, high-stakes requirements of a 21st-century power grid.

Antares Mark-0 becomes first advanced nuclear reactor to achieve criticality under DOE Pilot Program

Antares Nuclear Inc.’s Mark-0—a sodium heat-pipe-cooled microreactor fueled by high-assay low-enriched uranium (HALEU) tri-structural isotropic (TRISO) fuel compacts—has achieved zero-power criticality at Idaho National Laboratory’s (INL’s) Reactor and Critical Experiment (RACE) facility, becoming the first advanced reactor to reach that milestone under the Department of Energy’s (DOE’s) Reactor Pilot Program.

Antares achieves initial criticality of a privately developed advanced reactor under DOE pilot program

Antares today announced that its Mark-0 microreactor achieved initial criticality at Idaho National Laboratory (INL) under U.S. Department of Energy (DOE) authorization — making Antares the first private company to bring an advanced reactor to criticality under the DOE Reactor Pilot Program. The demonstration was conducted in partnership with DOE, INL, and BWX Technologies, Inc. (BWXT), with integration and observation support from the U.S. Army.

Department of Energy celebrates first advanced reactor criticality

The rebirth of America’s nuclear industry has officially arrived. Today, as part of the U.S. Department of Energy (DOE) Reactor Pilot Program, Antares Nuclear’s advanced reactor design, the Mark-0, successfully completed a zero-power fueled criticality demonstration at DOE's Idaho National Laboratory. This test confirms that the reactor can operate safely and establishes a basis that would allow subsequent reactors to produce electricity in 2027 and beyond. The Mark-0 is the first of multiple advanced reactors anticipated to go critical by the July 4th deadline set by President Trump in his May 2025 executive order.

Approval milestone for U.S. microreactor project

The Preliminary Documented Safety Analysis establishes the preliminary safety basis for a criticality test of the reactor, documenting how the design meets the US Department of Energy's (DOE) requirements for hazard analysis, accident mitigation, and operational controls. Approval of the Preliminary Documented Safety Analysis means Deployable Energy is now positioned to complete final preparations for its upcoming demonstration, including commissioning and startup activities under DOE oversight, the company said.

Deployable Energy secures PDSA approval for Unity Microreactor, advancing toward demonstration

Deployable Energy today announced that it has received approval of its Preliminary Documented Safety Analysis (PDSA) for its Unity microreactor criticality test, marking a critical milestone in the U.S. Department of Energy (DOE) safety authorization process and enabling the company to proceed toward reactor demonstration.

Historic Idaho EBR-II Dome transformed into nation’s first microreactor test bed

The historic Experimental Breeder Reactor-II dome at Idaho National Laboratory in Arco has been transformed into the nation's newest nuclear testing site. The facility will operate as the world's first purpose-built test bed for fueled microreactors.