Corium — DOE Reactor Pilot: The Verdict

DOE Reactor Pilot Circuit · Executive Order 14301

THE

VERDICT

CONCLUDED

Deadline

PASSED · July 4, 2026

Target: zero-power criticality · Independence Day.

Achieved Criticality

Did Not · By Deadline

Reactors That Went Critical

Ward 250 · Jun 22, 2026

FINAL GRID

FROZEN AT DEADLINE · RANKED BY SCORE

CLICK A ROW TO JUMP TO DETAIL CARD

AFTERMATH

POST-DEADLINE · DOE PILOT COMPANIES

The story didn't end on July 4, 2026. The circuit just changed from sprint to consequences.

radiantFebruary 17, 2026Radiant Adds Lockheed Martin as Strategic Investor to Oversubscribed Funding RoundInvestment underscores growing confidence in Radiant’s commercialization plan.radiant radiantRadiant’s Kaleidos Nuclear Microreactor to Power U.S. Air Force BasesJune 12, 2026radiant radiantInside a company making nuclear reactors the size of a shipping containerApril 9, 2026radiant radiantinfo@radiantnuclear.comradiant radiantTori Shivanandan: America knows we need nuclearAugust 28, 2026radiant radiantWhen America goes nuclear, it will go 'portable nuclear first,' Radiant president saysradiant radiantAugust 12, 2026Kaleidos Has Left the BuildingRadiant's Reactor Is En Route to The INL DOMEradiant radiantJuly 23, 2026DOE Selects Radiant for Second HALEU AllocationFuel allocation advances Radiant’s planned deployment of resilient nuclear power for critical U.S. national security missionsradiant radiantMay 5, 2026Radiant on Track to Build the First Commercial Nuclear Microreactors Factory in AmericaNRC Launches Accelerated Review of 10 CFR Part 70 License for R50 Production Facility in Tennesseeradiant radiantJuly 1, 2026Radiant Receives First TRISO Fuel Shipment at INL's DOME Facility, Clearing Path to Full-Power, Full-Temperature TestingFive Phase Testing Program Targets More Than 150 Hours at Full Power Without Operator Interventionradiant radiantUS Army awards up to $2.2 billion to five companies to build microreactors on basesAugust 26, 2026radiant radiantHow one company plans to put a nuclear microreactor at BuckleyMay 26, 2026radiant

11 PROJECTS · DETAIL VIEW

THE FIELD

✓ZERO-POWER CRITICALITY ACHIEVED — JUN 4, 2026

Antares Nuclear

Mark-0 · Sodium Heat Pipe Microreactor

Sodium Heat Pipe Microreactor

Idaho National Laboratory

HALEU

YES

Mark-0 microreactor achieved initial criticality at INL in early June 2026 — first privately developed advanced reactor to go critical under the DOE Pilot Program (announced 4 June 2026).

✓ZERO-POWER CRITICALITY ACHIEVED — JUN 22, 2026

Valar Atomics

Ward 250 · High-Temperature Gas-Cooled

High-Temperature Gas-Cooled

SIZE

Sub-critical test / 250 kWe

FUEL

HALEU TRISO

SITE

San Rafael Energy Lab, Emery County, Utah

HALEU

YES

Ward 250 achieved zero-power (cold) criticality at the San Rafael Energy Lab in Utah (announced 22 June 2026) — second in the DOE Pilot Program and the only achiever outside Idaho National Laboratory.

✓ZERO-POWER CRITICALITY ACHIEVED — JUL 1, 2026

Idaho National Laboratory

HALEU

Unity demonstration reactor achieved zero-power criticality at INL on 1 July 2026 — third DOE-authorized advanced reactor to go critical, the milestone DOE cited as meeting the President's goal of three criticalities by 4 July. Achieved under the Nuclear Energy Launch Pad.

✓ZERO-POWER CRITICALITY ACHIEVED — JUL 4, 2026

Aalo Atomics

Aalo-X · Sodium-Cooled Fast Reactor

Sodium-Cooled Fast Reactor

SIZE

10 MWe

FUEL

LEU (uranium dioxide)

SITE

Idaho National Laboratory

HALEU

Aalo-X Critical Test Reactor achieved criticality at INL at 00:20 MT on 4 July 2026 — fourth and final achiever, meeting the deadline; groundbreaking to criticality in under 8 months.

Radiant Industries

Kaleidos · Helium Gas-Cooled Microreactor

Helium Gas-Cooled Microreactor

INL DOME Facility, Idaho

HALEU

YES

PDSA approved February 2026. Targeting 60 effective full power days operation in 2026 at INL DOME. Signed binding HALEU contract with Urenco — first public commercial HALEU contract by US advanced reactor developer.

Oklo

Aurora-INL · Sodium Fast Microreactor

Sodium Fast Microreactor

SIZE

75 MWe

FUEL

Metallic U-Zr (recycled EBR-II fuel)

SITE

Idaho National Laboratory

HALEU

Broke ground Aurora-INL September 2025. NSDA approved for Aurora Fuel Fabrication Facility November 2025. Also in Fuel Line Pilot Program. Two projects in DOE Pilot total.

Deep Fission

Gravity Nuclear Reactor · Underground Borehole PWR

Underground Borehole PWR

OTA signed December 2025. Unique design: small PWR deployed in a borehole 1 mile underground. Targeting criticality July 2026 but design complexity is significant challenge.

Terrestrial Energy

Project TETRA (IMSR) · Integral Molten Salt Reactor

Integral Molten Salt Reactor

SIZE

195 MWe

FUEL

Low-enriched fluoride salt

SITE

TBD

HALEU

OTA signed January 2026. Also selected for DOE Fuel Line Pilot Program September 2025. July 4 criticality target is ambitious for this design complexity.

Last Energy

PWR20 · Pressurized Water Microreactor

Pressurized Water Microreactor

Selected August 2025. Limited public updates since selection. Primary commercial focus appears to be European market. July 4 criticality timeline unclear.

Atomic Alchemy

VIPR · Light Water Versatile Isotope Production Reactor

Light Water Versatile Isotope Production Reactor

Oklo subsidiary focused on radioisotope production for medical and industrial uses. VIPR is purpose-built for isotope production not power generation.

Natura Resources

ACU Molten Salt Reactor · Molten Salt Research Reactor

Molten Salt Research Reactor

Abilene Christian University, TX

HALEU

YES

DOE committed HALEU to ACU partner. ACU received NRC construction permit for research reactor. Natura plans to file two commercial NRC license applications.

MILESTONE KEY

M1 SELECTED (+10)

M2 OTA (+15)

M3 NSDA (+15)

M4 PDSA (+20)

M5 CONSTRUCTION (+15)

M6 FDSA (+10)

M7 CRITICALITY (+10)

M8 POWER (+5)

SOURCE: DOE-NE · EO 14301 (May 2025) · World Nuclear News, ANS Nuclear Newswire, DOE press releases · criticality outcomes verified July 2026