# Senior Nuclear Thermal-Hydraulics Engineer at Radiant

- Company: Radiant
- What the company does: Radiant builds Kaleidos, a portable, factory-built nuclear microreactor that delivers a megawatt of clean power anywhere it is needed. Backed by a16z, Felicis and USV.
- Company website: https://www.radiantnuclear.com
- Type: Startups
- Level: Senior
- Location: El Segundo, CA
- Work setup: On-site
- Pay: $140K to $197K base salary per year (USD)
- Posted: 2026-08-07
- Apply by: 2026-10-08
- Apply: https://jobs.ashbyhq.com/radiant-industries/27b08895-351e-441f-a8b5-abde955697b6
- Page: https://www.1752.vc/careers/jobs/radiant-senior-nuclear-thermal-hydraulics-engineer/

## About the role

Radiant is seeking a Senior Nuclear Thermal-Hydraulics Engineer to lead thermal-hydraulics and coupled physics analysis for the Kaleidos microreactor. You will own the modeling that determines how heat, coolant, and reactor core behavior interact under normal and accident conditions — work that directly informs core design, cooling systems, and safety case development for the first mass-produced nuclear reactor.

## What they're looking for

- Bachelor's degree in nuclear engineering, mechanical engineering, physics, or similar field from an accredited institution
- 5+ years of relevant industry or national laboratory experience
- Experience with thermal-hydraulics analysis and/or reactor systems codes (e.g., RELAP5, TRACE, CTF/COBRA-TF, SAM, TRANSFORM)
- Experience with high-temperature (500°F+) heat transfer analysis involving conduction, convection, and radiation
- Experience communicating and distilling technical information with cross-functional teams
- Experience with coupled multiphysics modeling (e.g., MOOSE, BISON, MARMOT) or neutronics coupling

Tags: Engineering