Greg Piefer

Greg Piefer is the founder and CEO of SHINE Technologies, a nuclear fusion company based in Janesville, Wisconsin, focused on advancing fusion from a research objective to a commercially viable business. Piefer established the company while pursuing a doctorate in nuclear engineering at the University of Wisconsin–Madison, with the goal of incrementally commercializing fusion technology to generate practical value at each stage. He holds bachelor's degrees in physics and electrical and computer engineering from the University of Wisconsin–Madison and completed his doctorate in nuclear engineering and engineering physics, studying nuclear fusion under Gerald Kulcinski.

Before launching SHINE Technologies, Piefer founded Phoenix Nuclear Labs, which developed high-yield neutron generators for defense and medical applications. He also served as chief technical officer at Gillware Inc., a data recovery and backup company.

At SHINE Technologies, Piefer has implemented a phased approach to commercializing fusion, initially focusing on neutron production—the highest-value product of fusion. The company's first phase supports the aerospace, defense, and energy industries by generating neutrons for nondestructive testing, including neutron radiography to inspect components used in jet engines and spacecraft and to ensure the reliability of defense systems. SHINE Technologies has expanded into medical isotope production and is recognized as the largest producer of non-carrier-added lutetium-177 in North America, distributing its product, "Ilumira," globally. The company's Chrysalis facility is designed to produce millions of doses of molybdenum-99 annually.

Under Piefer's leadership, SHINE Technologies has achieved several technical milestones, including holding the world record for a nuclear fusion reaction in a steady-state system, with a yield of approximately 50 trillion neutrons per second. SHINE Technologies became the first non-utility to complete the Nuclear Regulatory Commission's technical review of an operating license application in decades. The company has formed partnerships with organizations such as the U.S. Department of Energy's Advanced Research Projects Agency–Energy, Argonne National Laboratory, the University of Wisconsin–Madison, Orano, and the UK Atomic Energy Authority, which selected SHINE Technologies to supply neutron generators for its global fusion research program. SHINE Technologies has also secured significant funding to support the scaling and commercialization of its fusion technology.

Piefer is the primary inventor on multiple patents and has authored or co-authored numerous publications. He serves on the boards of several for-profit and nonprofit organizations. His work has been recognized by the University of Wisconsin–Madison College of Engineering with the Early-Career Achievement Award. Piefer and SHINE Technologies have been featured in Science magazine in an article titled "Making Fusion Pay," which examined the company's approach to commercializing fusion technology. He has participated in industry panels, including at SXSW, discussing fusion timelines and commercial realities.

Piefer leads a multidisciplinary team of physicists, nuclear engineers, radiochemists, and strategists from the nuclear, medical, and manufacturing sectors, all working toward the goal of developing, operating, and scaling fusion technology. SHINE Technologies' roadmap includes medical isotope production, industrial inspection, recycling spent nuclear fuel, and the eventual generation of clean fusion power. Piefer is recognized as a prominent voice in the global energy sector, contributing to the ongoing conversation about the future of nuclear fusion and clean energy.