Fact orig-012
newanalysisconfirmed Utah's energy-lab page calls June 18 'full-power' criticality; DOE and ANS called it zero-power
The Utah San Rafael Energy Lab's project page (a State of Utah site, read 2026-09-29) says Ward 250 achieved 'full-power fueled criticality' on June 18, 2026, describes it as a Generation IV helium-cooled, graphite-moderated HTGR, and says the design is meant to scale to a 5 MW version. DOE's release and ANS both describe June 18 as a zero-power criticality demonstration, and Valar's own Castle Country page says full power came 'days later'. The state page's wording therefore conflicts with the federal record; it also repeats the company-style claim that the fuel is 'impossible to melt', which is a design claim, not a demonstrated result.
In plain termsUtah's own lab web page says the reactor reached 'full-power' criticality on June 18. The federal record says it was a zero-power test that day, and even Valar says full power came days later. The state page overstates what happened on June 18.
- Valar Atomics | Utah San Rafael Energy Lab (Utah San Rafael Energy Lab (State of Utah)) primary government “the Ward 250 successfully achieved full-power fueled criticality at the lab”
- Department of Energy Celebrates Second Advanced Reactor Achieving Criticality (U.S. Department of Energy, 2026-06-18) primary government “successfully completed a zero-power fueled criticality demonstration”
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