Graduate Mechanical Engineer — Nuclear Microreactor Design

Radiant, Inc.; El Segundo (CA); Hybrid; USD 60,000 - 85,000; Full time

Benefits offered by this job

Stock plan

Medical insurance

One Medical memberships

Vision plan

Dental plan

Voluntary benefits

Parental leave (8 weeks)

Daily catered lunch

Flexible PTO

Team events

Job summary

Radiant, Inc. in El Segundo, CA is building the world’s first mass-produced, portable nuclear microreactors.

We seek an engineer to contribute to design, analysis, and testing, taking ownership from concept through build with guidance from senior engineers. You will collaborate across disciplines, participate in design reviews, and help accelerate development while benefiting from equity grants and a strong benefits package.

Qualifications

• BS or MS in Mechanical Engineering, Aerospace Engineering, or a related discipline.
• Graduating in December 2026 or Spring 2027.
• Strong foundation in engineering first principles (thermodynamics, fluid mechanics, statics, dynamics, strength of materials).
• Hands-on design/build experience through projects, research, labs, or internships.
• Proficiency with engineering tools (CAD, analysis software, lab instrumentation).

Responsibilities

• Contribute to the design, analysis, and testing of our microreactor.
• Take ownership of deliverables from concept through build and validation, with guidance from senior engineers.
• Collaborate across disciplines to integrate designs and resolve technical challenges.
• Support system-level testing, troubleshooting, and design iteration to accelerate KDU development.
• Communicate results through design reviews, technical reports, and presentations to peers and leadership.

Skills

Mechanical Eng

Aerospace Eng

First principles

CAD tools

Lab instrumentation

Education

BS or MS in Mechanical or Aerospace Engineering

Tools

CAD

Analysis software

Lab instrumentation

Job description

Radiant, Inc. in El Segundo, CA is building the world’s first mass-produced, portable nuclear microreactors.

We seek an engineer to contribute to design, analysis, and testing, taking ownership from concept through build with guidance from senior engineers. You will collaborate across disciplines, participate in design reviews, and help accelerate development while benefiting from equity grants and a strong benefits package.