Mirion Supports Advanced Reactor Criticality Milestones Through U.S. DOE Reactor Pilot Program

Mirion Technologies and Paragon Energy Solutions Provide Radiation Monitoring and Nuclear Safety Systems for Advanced Reactor Demonstrations

ATLANTA--(BUSINESS WIRE)--Mirion, a global leader in radiation safety, science, and medicine, announced today that its Mirion Technologies and Paragon Energy Solutions businesses supported multiple advanced reactor designs that have achieved criticality milestones in the U.S. Department of Energy (DOE) Reactor Pilot Program, established under Executive Order 14301.

In May 2025, the Administration issued executive orders to strengthen and accelerate the U.S. nuclear industry. Executive Order 14301 directed the DOE to bring at least three advanced reactor designs to criticality by July 4, 2026. Of the 11 projects initially selected, four achieved criticality — the ability to sustain a controlled nuclear chain reaction.

Across these efforts, Mirion Technologies and Paragon provided products, systems, and expertise spanning reactor protection, neutron flux monitoring, radiation monitoring, health physics, radiation protection and radiochemistry. These capabilities helped developers reach criticality safely and advance their projects.

Congratulating the DOE, Idaho National Laboratory and Reactor Developers

Mirion congratulates the U.S. DOE, Idaho National Laboratory (INL) and the reactor developers on these landmark achievements. As host to a number of participating reactor efforts and a national leader in advancing reactor innovation, INL provided the infrastructure, expertise, and testing capability that helped make these milestones possible. The program’s success reflects the shared commitment of the DOE, its national laboratories, and industry partners to demonstrating that the United States can develop and deploy advanced nuclear technology at pace.

“Achieving criticality is a defining milestone in advanced reactor development, and we are proud to support the teams building the next generation of nuclear energy,” said Tighe Smith, Chief Nuclear Officer of Mirion and Paragon. “What this program has shown is that an ambitious schedule is achievable when government, the national laboratories and industry work as one team toward a shared goal. That momentum is a real breakthrough. It proves we can move quickly and, importantly, safely sustain that pace as advanced nuclear moves from demonstration toward broad deployment.”

Mirion Nuclear Solutions — Mirion Technologies, Paragon Energy Solutions and Certrec — provides integrated capabilities spanning reactor safety, radiation monitoring, regulatory compliance and operational readiness from demonstration to commercial deployment.

About Mirion

Mirion is a global leader in radiation safety, science and medicine, empowering innovations that deliver vital protection while harnessing the transformative potential of ionizing radiation across a diversity of end markets. Focused on nuclear and safety, the Mirion Technologies group is committed to powering advancements in nuclear energy through proven radiation safety technologies and expertise. Dedicated to driving better patient outcomes, the Mirion Medical group is focused on improving quality in cancer care through its broad range of solutions that enhance the delivery and ensure safety across the medical landscape. Headquartered in Atlanta (GA – USA), Mirion employs approximately 3,200 people and operates in 12 countries. Learn more at mirion.com.