Aalo Atomics Pushes US Advanced Nuclear Program Past Its July Target With Fourth Criticality
The fourth US reactor to achieve criticality under the DOE demonstration program clears a political milestone, but commercial power delivery for the sector remains years away.
Aalo Atomics achieved criticality on a commercial-scale advanced nuclear reactor on July 8, 2026, becoming the fourth US design to reach that stage under a federally supported demonstration campaign, according to the Department of Energy. The Austin-based company said it had proven the physics of its 10 MWe reactor core, which will be deployed in 50 MWe "Aalo Pods" designed to power AI data centers, with an on-site data center expected to draw power from the unit in 2027.5
Four designs clearing the bar exceeds the minimum set by President Trump's executive order of May 23, 2025, which called for at least three advanced reactors to achieve criticality by July 4, 2026 — the US independence anniversary. That order is part of a broader push to grow US nuclear capacity from roughly 100 GW to 400 GW by 2050.5,2
The DOE-backed campaign had already logged two earlier milestones. Antares Nuclear Inc achieved initial criticality on a TRISO-fueled microreactor on June 10, 2026, the first design to reach that stage under the administration's program.2 Valar Atomics followed on June 19, 2026, taking its Ward 250 — a 100 kWt modular high-temperature gas reactor scalable to 5 MWe — through zero-power testing at Utah's San Rafael Energy Lab.4
Scale is the problem all three designs share. Aalo's 10 MWe unit is small against the 400 GW ambition, and clustering units into 50 MWe pods still leaves the technology orders of magnitude behind a conventional reactor or a large gas plant. The program's own target of three criticalities by July was a proof-of-concept marker. It was not a commercial deployment signal.5
On the non-nuclear side of the administration's baseload push, the DOE's $525 million coal-revival program awarded $18.5 million in June 2026 to TerraSpark Energy Campus, a 1.6 GW greenfield project in West Virginia pairing Babcock & Wilcox supercritical boilers with molten borate carbon capture.3 Combined with $21.5 million in non-federal cost share, the scoping-and-design phase totals roughly $40 million, with a 2030 startup target and a 95% to 98% capture design.3
TerraSpark's award was the smallest of four in its category, reflecting the project's early stage. Developer Bill Tolpegin framed the investment in demand terms: "Electricity demand in the United States is growing rapidly, and we need infrastructure that can keep up."3 The project still faces permitting, financing, and technology demonstration hurdles before it contributes a single megawatt to the grid.
Data center growth, manufacturing reshoring, and electrification are all pushing utilities and policymakers to look past wind and solar for firm capacity. Both the nuclear and coal programs are responses to the same demand pressure. But the gap between a successful criticality test and commercial power output is wide, and it would be premature to price 400 GW of nuclear or 1.6 GW of coal-fired capture into forward curves.3
How quickly baseload assumptions can shift is visible elsewhere. High LNG prices have pushed India back toward domestic coal, with peak power demand reaching an all-time high of 257 GW, and coal plants supplying upwards of 75% of that load.1 Russian coal imports into India jumped 95% in the first quarter of 2026, while South Korea abolished the spring regulatory cap that had historically limited coal plants to 80% capacity, ramping nuclear utilization to as much as 80%.1
The US is not India. The economics differ, and the political drivers are distinct. But the pattern of policy-driven baseload hedging in response to demand growth is recognizable across both. What remains absent in the US case is a credible commercial bridge from demonstration to serial deployment, spanning fuel supply chains, manufacturing scale, and grid interconnection.2,4,5
Aalo's planned 2027 on-site data center connection is the next concrete signal. If that slips, the gap between demonstration physics and operational megawatts will be measured in years. If it holds, the advanced reactor pipeline begins to look like something a power buyer can actually underwrite.5