Announcement • Jun 26
Hadron Energy, Inc. Appoints Brian Arnholt as Director of Reactor Systems Hadron Energy, Inc. announced that Brian Arnholt is appointed as Director of Reactor Systems. Brian Arnholt leads reactor systems engineering for the Halo MMR, bringing three decades of nuclear leadership across first-of-a-kind design, development, and licensing. Most recently he served as a Senior Consultant in digital modernization at Sargent & Lundy and was an I&C consultant to TerraPower’s Natrium project. He spent nearly a decade at NuScale Power as Engineering Manager and Principal Engineer for Instrumentation & Controls, where he authored the I&C content of the NuScale Design Certification Application and helped secure U.S. NRC approval of the design’s I&C systems, a milestone for small modular reactor licensing. Earlier, he served as Director of I&C & Simulation for Babcock & Wilcox’s Generation mPower SMR venture, led plant control systems engineering at General Electric, and held reactor engineering and operations supervisor roles at Exelon, including Senior Reactor Operator license training. He holds a B.S. in Nuclear Engineering (cum laude) from the University of Michigan and is a published author on SMR I&C design and licensing. Announcement • Jun 16
Hadron Energy Announces Publication of Its First U.S. Patent Application for the Integral Architecture Behind the Halo Micro-Modular Reactor Hadron Energy, Inc. announced that the United States Patent and Trademark Office (USPTO) published the Company’s first patent application, “Micro Integral Nuclear Reactor” (Publication No. US 2026/0128185 A1), on May 7, 2026. The application is the foundational technical disclosure behind Hadron’s flagship Halo Micro-Modular Reactor (MMR) and the first entry in the Company’s growing intellectual property portfolio. Filed October 31, 2025 and claiming priority to a November 1, 2024 provisional application, it names Samuel Gibson and Ross Ridenoure among its inventors, alongside Christopher R. Neal and Andrew M. Ward. Hadron Energy's 10 MWe Halo MMR integrates the reactor core, steam generator, pressurizer, and primary coolant system in a single transportable pressure vessel, the architecture at the heart of the Company's first published U.S. patent application. The application describes the integral pressurized-water architecture at the heart of the 10 MWe Halo MMR, in which the reactor core, steam generator, pressurizer, and primary coolant system are housed within a single reactor pressure vessel. By integrating the primary system inside one vessel, the design eliminates the large-bore external piping found in conventional plants — simplifying transport and assembly and, as described, removing the potential for a large-break loss-of-coolant accident from the design basis. The application discloses a reactor producing thermal output in the range of 6 to 60 megawatts-thermal and electrical output of 2 to 20 megawatts-electric, of which the Halo’s 10 MWe configuration is the Company’s lead design. The application further describes a transportable, factory-fabricated pressure vessel formed from segments joined by circumferential flanges, enabling a sealed, tested reactor to ship by conventional road or air transport — along with passive safety provisions that, in described embodiments, maintain core cooling without alternating-current power for an extended period under design-basis conditions. The Halo is fueled by Low-Enriched Uranium Plus (LEU+), supporting a multi-year fuel cycle while relying on an established, domestically supported fuel supply chain rather than experimental materials. The publication follows the recent NRC staff acceptance of Hadron’s Quality Assurance Program Description and the Company’s submission of its Principal Design Criteria white paper to the NRC, part of a coordinated effort to advance the Halo MMR through licensing. Together, these milestones reflect Hadron’s aspiration to become the first company to bring a licensed light-water microreactor to market and to establish a defensible technology position. 
