Epithermal Power
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About Epithermal

A Team That Has Built Real Reactors.

Career reactor and space-nuclear engineers from DOE national labs, DoW, and NASA: the brains behind real national reactor programs.

Who We Are

Next-Gen Reactor Engineering, in One Shop

Epithermal Power LLC is a minority-owned small business in Los Alamos, New Mexico. Our team brings backgrounds from DOE (LANL, SNL, INL), DoW (DARPA, U.S. Army), and NASA: a deep bench in cutting-edge nuclear engineering, serving government agencies and private companies alike.

Why Us

We're Not Reactor Tourists

Micro- and space-reactors are our craft, not a trend

  • Real reactors : designed and built for the nation, not slideware
  • Deep, not broad : years inside the actual U.S. micro- and space-reactor programs
  • In the room : when the government needs a reactor designed, our people are at the table
9+
Reactor Designs in Portfolio
5+
Government Reference Designs Built for the U.S.A.
Decades
Space-Nuclear Power & Propulsion Experience
Track Record

We've Already Done the Hard Part.

Critical experiments, criticality-safety analysis that authorized a fuel-fabrication facility, space-reactor test hardware, and the government's reference designs, delivered across DOE, NNSA, DoW, DARPA, and NASA.

Selected Work

From Design to Criticality

DOE · NASA · DoW

Space-Reactor Test Hardware, Criticality to Full Power

Designed test hardware for DOE, NASA, and DoW space-reactor demonstration programs, including one that reached criticality and 28 hours of full-power operation, the first new U.S. fission reactor built and tested in four decades.

DOE · DoW

Critical Reactor Experiment, Lead Engineer

Led a high-priority experiment end to end: design, optimization, multiphysics, material down-selection, safety, and full systems integration.

NNSA

Fuel-Fabrication Facility Authorized

Criticality-safety analysis that enabled successful authorization of a new fuels-fabrication facility at a DOE/NNSA complex.

NASA · DOE

Space Power & Propulsion Reference Designs

Authored U.S. government reference designs for space surface power and nuclear electric propulsion, the designs peer programs are measured against.

DOE

Accelerated Fuel Qualification

Reactor-engineering lead on a multi-million-dollar effort to accelerate metallic-fuel qualification.

DARPA · NASA

Cislunar Propulsion Demonstration

Supporting a cislunar nuclear-propulsion demonstration with software integration, nuclear testing, and launch safety.

DOE · NASA · DoW

End-to-End Reactor Multiphysics

Invented a one-click, finite-element multiphysics framework that runs reactor analysis end to end, now driving national reactor programs across DOE, NASA, and defense.

DoW · NASA

Nuclear Thermal Propulsion Research

Directed reactor R&D for nuclear thermal propulsion and delivered launch-safety peer review for next-generation space missions.

DOE · Industry

Independent Microreactor Reviews

Independent multiphysics reviews of government and commercial microreactors, coupling neutronics, thermal-hydraulics, and full-scale reactor dynamics.

Let's Build the Reactors That Power Earth and Space.

Partner with a team that has taken reactors from design to criticality.

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