US Advanced Reactor Cohort Reaches Fourth Criticality as DOE Program Nears July Target
Four US advanced reactor designs have now achieved criticality, with uranium ETF prices jumping 3.94% as the DOE program approaches its July 2026 benchmark.
Aalo Atomics said its commercial-scale advanced nuclear reactor has achieved "criticality," making it the fourth US design to do so under a federally supported campaign, according to the Department of Energy. The company said the Criticality Test Reactor includes a full-scale core demonstrating nuclear components of its 10 MWe reactors, which will be deployed in 50 MWe Aalo Pods to power AI data centers.5
That milestone matters because the Trump administration's May 23, 2025 executive order set a target of at least three advanced reactors reaching criticality by July 4, 2026, as a stepping stone to grow US nuclear capacity from about 100 GW to 400 GW by 2050. With four designs now past that stage, the program has overshot its own benchmark. Uranium ETF URA traded at $42.49 on Wednesday (2026-08-05), up 3.94%.5,2
The fourth criticality follows two earlier successes. Antares Nuclear Inc said it achieved initial criticality on a microreactor design using TRISO fuel, the first to reach that stage under the administration's program. Valar Atomics then completed zero-power testing at its Ward 250, a Gen IV TRISO-fueled modular high-temperature gas reactor at Utah's San Rafael Energy Lab in Emery County.2,4
Ward 250 is rated at 100 kWt initial test power, scalable to 5 MWe, with Kiewit Nuclear Solutions serving as engineering, procurement and construction contractor. "Criticality proves the physics; power operations prove the engineering," Valar said, as the company moves toward full-power testing.4
Aalo said it built 10 MW worth of fuel assemblies and manufactured and quality-controlled commercial scale systems in-house. The company plans for its new reactor to produce 10 MWe of electricity and power an on-site data center in 2027.5
But the criticality milestones tell only part of the story. The DOE's $525 million program, launched in September 2025 under executive orders "Reinvigorating America's Beautiful Clean Coal Industry" and "Strengthening the Reliability and Security of the United States Electric Grid," funds both nuclear and fossil pathways.3
A $350 million DOE coal-revival program has put $18.5 million toward the TerraSpark Energy Campus, a 1.6-GW greenfield project in West Virginia pairing Babcock & Wilcox supercritical boilers with Mantel Capture's molten borate carbon capture. Developer TerraSpark announced the award on June 4, with a 2030 startup target and a 95% to 98% capture design. Combined with $21.5 million in non-federal cost share, the scoping and design phase carries a total value of roughly $40 million.3
The coal award is the smallest of four Topic Area 1 grants, reflecting its early stage. Yet its selection signals that surging electricity demand from data centers, manufacturing and electrification is forcing a fresh look at baseload coal, a sector that COP26 pledges and G7 commitments had seemingly relegated to decline.3,1
The parallel tracks raise a question traders are starting to price. Coal ETF COAL sat at $22.89 on Wednesday (2026-08-05), up 2.60%, while Newcastle physical coal traded at $117.90/t. German power for the front month closed at €130.04/MWh on Tuesday (2026-08-04), down 1.82%.3
Internationally, the coal revival is not confined to the US. India's peak power demand has surged to an all-time high of 257 GW, with coal-fired plants providing upwards of 75% during peak load periods. Indian coal imports from Russia alone jumped 95% during the first quarter of the year, as high gas prices forced the country to prioritize cheaper domestic coal.1
South Korea has abolished the spring-time regulatory cap that historically limited coal-fired plants to 80% capacity, and nuclear utilization has been ramped up to as much as 80% to pre-empt supply risks. These moves come as India imports about 60% of its LNG through the vulnerable Strait of Hormuz.1
The next test for the US nuclear cohort is whether criticality translates to commercial power within the program's timeline. Aalo targets 2027 for its first data center connection; Valar must complete power ascension testing at Ward 250. The uranium move suggests investors are betting the milestones hold, but the gap between physics demonstrations and grid-connected megawatts remains the unproven variable.