About the role#
Radiant is hiring a Thermal Engineer Intern for the Summer 2027 term. You will join our engineering research and development team in El Segundo to support the design and performance evaluation of our Kaleidos microreactor systems. This is a full-time, paid, on-site role.
What you'll do#
- Develop and execute thermal analysis and CFD to evaluate the performance of Kaleidos systems.
- Document your analysis results to provide clear and actionable outputs for the team.
- Manage the pipeline for producing analysis geometry from mechanical design CAD.
- Improve CFD capabilities, accuracy, and workflow efficiencies through dedicated projects.
- Create methods and calculations to support and build confidence in lower-fidelity thermal analysis.
What you'll need#
- Current pursuit of a BS or MS in Chemical, Mechanical, or Aerospace Engineering.
- Independence in solving engineering tasks and a proactive approach to seeking resources.
- Ability to work effectively in a collaborative environment.
- Interest in our mission to deploy nuclear microreactors to remote locations.
- Prior internship experience is helpful but not required.
- Knowledge of reactor physics is preferred.
Location & details#
- This internship is based 100% on-site at our headquarters in El Segundo, California.
- This position involves access to technology subject to U.S. export controls. Any offer is contingent upon your capacity to serve in compliance with these controls.
About Radiant
Radiant produces portable nuclear microreactors. The company is based in El Segundo, California and employs between 51 and 200 people. It was founded in 2020. The firm is currently developing a 1 MW failsafe microreactor known as Kaleidos.
How to get in at Radiant
Applying early to Radiant gives you a clear advantage because recruiters review applications as they arrive. Intern Insider sends an instant alert the moment a role is published, so you can apply among the first before the pile grows. You should aim to reach out to the recruiters behind these roles directly to ask about the position or a referral, as this approach often improves response rates. Intern Insider surfaces these specific contacts for you, helping you move past the standard queue.



