Four private advanced reactors reach criticality

President Donald Trump announced on July 24, 2026, that four privately funded advanced nuclear reactors have reached criticality, marking a significant milestone for the U.S. civilian nuclear energy sector. The announcement, made during an Oval Office ceremony with company executives and administration officials, exceeded a stated goal of having three new reactors operational by the nation's 250th anniversary on July 4.

The president described the achievement as a historic milestone and a miracle, noting that the United States had not seen a privately funded advanced reactor reach this stage since 1974. The four companies involved are Aalo Atomics, Antares Nuclear Inc., Deployable Energy, and Valar Atomics. Officials said the rapid progress was enabled by a series of executive orders signed in May 2025 aimed at reducing regulatory burdens and accelerating nuclear innovation through a Reactor Pilot Program.

Antares Nuclear was the first to achieve criticality on June 4, with plans for energy production by 2027 and potential use for military installations and future space missions before 2028. Valar Atomics reached the milestone around mid-June with its Ward 250 reactor, targeting...