Dr. Gregory Piefer is Founder and CEO of SHINE Technologies, a nuclear fusion company commercializing fusion-based technology for medical isotopes, industrial testing, and clean energy. He holds three degrees from UW-Madison including a PhD in nuclear engineering and engineering physics with a minor in medical physics.

Piefer studied nuclear fusion under Dr. Gerald Kulcinski at University of Wisconsin-Madison, earning bachelor's degrees in physics and electrical and computer engineering in 1999, a master's in 2004, and his PhD in 2006. He previously served as President of Phoenix Nuclear Labs and CTO at Gillware Data Recovery.

Piefer holds multiple patents in fusion technology and has nearly 20 years of executive management experience commercializing scientific breakthroughs. SHINE holds the world record for steady-state nuclear fusion at 50 trillion neutrons per second and received the 2025 Chancellor's Entrepreneurial Achievement Award from UW-Madison.

SHINE has raised over $1 billion in total funding and became the largest producer of non-carrier-added lutetium-177 in North America in 2024. The company received the first completed NRC Final Safety Evaluation Report for a non-utility in 30+ years in 2023.

SHINE's Cassiopeia facility can produce up to 200,000 cancer treatment doses annually, and its fusion technology serves aerospace, defense, and healthcare markets globally. The company employs over 300 people across facilities in Wisconsin, Massachusetts, and the Netherlands.