Ahead of America’s 250th birthday, the Department of Energy’s Reactor Pilot Program hit its goal of having at least three advanced nuclear reactor projects reach criticality by July 4th, 2026. 

The four pilot projects include Antares Nuclear’s Mark-0 reactor, Valar Atomics’ Ward 250, Deployable Energy’s Unity, and Aalo Atomic’s Aalo-X. Notably, the Aalo-X hit criticality on Independence Day. The company said its Critical Reactor Test (CRT) succeeded within eight months of the project’s groundbreaking, and the company went from “founding to fission” in less than three years. 

As Independent Women’s Center for Energy and Conservation Senior Fellow Sarah Montalbano recently explained, criticality in a nuclear reactor occurs “when its fission chain reaction sustains itself, each round of neutrons splitting enough atoms to trigger the next without an outside source driving it.” 

DOE’s Reactor Pilot Program was established under Executive Order 14301 on Reforming Nuclear Reactor Testing at the Department of Energy, issued in May 2025 to fast-track the testing and licensing of new advanced nuclear reactor projects. 11 projects are currently enrolled in the pilot program to deploy new nuclear power. These mainly include microreactors and small modular reactors (SMRs). Microreactors have a capacity of 50 megawatts (MW) of electricity—or powering the equivalent of 10,000 to 50,000 homes. SMRs have a slightly larger capacity (50 MW to 300 MW) and can power about 50,000 to 300,000 homes.

Nuclear energy is clean, reliable, abundant, and uses the least amount of land of any available power source. After natural gas (41%), nuclear energy (18%) is the second-largest source of net electricity generated in the U.S. Despite years of misinformation and negative publicity following the 1986 Soviet Chernobyl disaster, support for nuclear energy is growing in America. Even a majority of American women—51%—now support this electricity source. 

The goal of this pilot program is not only to supercharge America’s nuclear renaissance but also to help meet growing electricity demand from projects including AI data centers. The Trump administration pledged to expand America’s nuclear energy capacity to 400 gigawatts (GW) by 2050—up from 100 GW in 2024. This is enough to power approximately 300 million homes. 

By all accounts, “Four by the Fourth” is an extraordinary achievement for America’s nuclear renaissance that should be celebrated by all.