Done when a reactor in the United States that is not a conventional large light-water plant (a small modular reactor, a microreactor, or a non-light-water design such as molten salt, sodium or high-temperature gas) first delivers electricity to a grid or to a paying customer. A construction permit, groundbreaking, fuel load or first criticality is a milestone, not done, and that includes DOE, DoD or university test reactors that go critical without sending power out. Restarts and uprates of existing plants, new large reactors such as the AP1000, and SMRs operating abroad do not count.
No US advanced reactor or SMR is producing power yet. TVA holds the furthest commercial permit, an NRC construction permit for a 300-MW BWRX-300 at Clinch River, but has not committed to build and still needs an operating license. Kairos has broken ground on Hermes 2; Oklo says its Groves isotope test reactor reached criticality earlier in 2026; Antares has initial DOE safety approval for Mark-1 and a BWXT TRISO fuel deal for an initial tonne, none of which is a license or power delivery. Fuel work is advancing: Westinghouse seeks an NRC amendment for a $1 billion LEU+ plant, GLE's Paducah plant has a regulator recommendation and Cameco as exclusive buyer, and Centrus shipped its first Piketon centrifuge. AEP and X-energy's 960-MW Indiana project remains at evaluation, the Molten Chloride Reactor Experiment aims for criticality as early as 2027, and DoD work includes an Aberdeen IMSR, Antares space reactor, Navy Radiant Kaleidos selection and SpaceNukes DARPA ground test.
2026-10-28: Antares received initial DOE safety approval for its Mark-1 microreactor and signed a BWXT advanced fuel fabrication agreement. — newgen — SMR industrial base: fuel cycle + supply chain stacking
2026-10-21: Kairos Power was reported to have broken ground on its Hermes 2 molten-salt demonstration plant. — newgen — SMR industrial base: fuel cycle + supply chain stacking
2026-10-19: Oklo reported that its Groves Isotope Test Reactor had reached criticality earlier in 2026, building on its work in DOE's Reactor Pilot Program. — newgen — Oklo's Groves-2: DOE follow-on, medical isotopes first
2026-10-08: Last Energy's micro-modular reactor at Texas A&M-RELLIS cleared its DOE Documented Safety Analysis, leaving a readiness review before fuel and operation. — newgen — DoD nuclear demos: Army leases, Aberdeen IMSR, Antares space reactor
2026-09-29: The NRC granted TVA the first US construction permit for a BWRX-300 small modular reactor, Unit 1 at Clinch River in Oak Ridge. — newgen — Clinch River: the country's first BWRX-300 construction permit
Small and advanced reactor developers are securing fuel and parts faster than reactors are licensed. Antares has a BWXT deal for an initial tonne of TRISO fuel and initial DOE safety approval for its…
Antares has a multi-year agreement with BWX Technologies to fabricate advanced nuclear fuel, starting with an initial tonne of TRISO fuel for its microreactors, with volumes possibly rising as…
NRC has approved TVA's construction permit for a GE Vernova Hitachi BWRX-300 at Clinch River, the first US construction permit for the design. The same reactor is being pursued in Europe through a…
The US military is advancing several nuclear demos: the Army conditionally awarded long-term installation-power leases to three companies, with Ameresco and Terrestrial Energy to deliver an IMSR at…
Cameco has become the exclusive buyer and seller of all output from GLE's planned Paducah Laser Enrichment Facility, and the US nuclear regulator now recommends that a construction and operation…
Westinghouse is investing $1 billion in a new LEU+ nuclear fuel factory at its Columbia Fuel Fabrication Facility in Hopkins, South Carolina, the first fleet-scale US fuel plant in more than 50…
TerraPower hosted senior government officials at its Natrium demonstration site in Kemmerer, Wyoming, the project's first appearance in this story; the officials were not named and no project…
American Electric Power and X-energy signed a joint development agreement to evaluate a 960-MW project made up of twelve Xe-100 small modular reactors at the former Breed coal plant site in Sullivan…
Oklo has announced plans for Groves-2, the next stage of its Groves project under a follow-on DOE program, initially focused on medical isotope production. It named the planned Groves-2 Forge isotope…
Quantum Leap Energy and Necsa have signed a binding heads of agreement to establish a joint venture for HALEU production in South Africa. The venture will develop, finance, build and operate a test…