Hadron Energy, Inc. (NASDAQ: HDRN) announced that the U.S. Patent and Trademark Office published the company's first patent application, titled "Micro Integral Nuclear Reactor" (Publication No. US 2026/0128185 A1), on May 7, 2026.

The application, filed October 31, 2025, and claiming priority to a November 1, 2024 provisional filing, covers the integral pressurized-water architecture of the company's Halo Micro-Modular Reactor (MMR). The inventors named in the application include CEO Samuel Gibson, Chief Nuclear Officer Ross Ridenoure, Christopher R. Neal, and Andrew M. Ward.

The design integrates the reactor core, steam generator, pressurizer, and primary coolant system into a single pressure vessel, eliminating the large-bore external piping found in conventional nuclear plants. The application discloses a reactor with a thermal output range of 6 to 60 megawatts-thermal and electrical output of 2 to 20 megawatts-electric. The Halo's lead configuration is rated at 10 megawatts-electric.

The pressure vessel is described as factory-fabricated from segments joined by circumferential flanges, allowing transport by conventional road or air. The design also includes passive safety provisions that, under described conditions, maintain core cooling without alternating-current power for an extended period. The reactor uses Low-Enriched Uranium Plus (LEU+) fuel.

"This first publication puts the engineering foundation of the Halo MMR on the public record and opens what we intend to be a deep intellectual property portfolio," Gibson said in a statement.

According to the company's press release, the patent publication follows the Nuclear Regulatory Commission staff's acceptance of Hadron's Quality Assurance Program Description and the submission of a Principal Design Criteria white paper to the NRC, steps the company describes as part of its reactor licensing effort.