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Radiant

a16z portfolio company

2027 New Graduate - Tooling Engineer

Location
El Segundo, California, United States
Work arrangement
On-site
Job type
Full-time
Compensation
$105K – $130K • Offers Equity

About the role

Posted Sep 17, 2026

About Radiant

Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt, fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development leverages modern software engineering to rapidly deliver safe, factory-built microreactors that use existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor at the Idaho National Laboratory this summer, with initial customer deliveries beginning in 2028.

Radiant is seeking a highly motivated Tooling Engineer to join the team.

Responsibilities:

  • Partner with design and manufacturing engineers to develop innovative production tooling for fabricating and assembling complex mechanisms and structures.

  • Design, analyze, and fabricate tooling that enables semi-remote operations for fueling/defueling of the reactor.

  • Identify and develop appropriate suppliers for tooling components, fabrication.

Qualifications:

  • BS or MS in Mechanical Engineering, Manufacturing Engineering, Aerospace Engineering, or related discipline.

  • Graduating in December 2026 or Spring 2027.

  • Understanding of both “hand calc” analytical methods and higher fidelity finite element-based analysis methods.

  • Self-motivated with strong organizational, written, and oral communication skills.

  • Experience with custom machine design; electromechanical systems, motors, actuators, linear rails, bearings, lifting/rigging, etc.

  • Strong problem-solving skills and attention to detail.

  • Demonstrated ability to work collaboratively with design and operations teams.

Benefits and Perks

  • Stock: Substantial incentive stock plan for all full-time employees.

  • Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.

  • One Medical: Sponsored memberships for employees and their dependents.

  • Vision: 100% top tier plan coverage + 50% for dependents.

  • Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.

  • Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.

  • 8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.

  • Daily catered lunch. Free snacks and drinks.

  • Flexible PTO policy. Remote workday allocation.

  • Company and team-bonding events, happy hours and in-person camaraderie.

  • Beautiful El Segundo headquarters close to the Pacific Ocean.

Total Compensation and Benefits
Radiant compensates people for impact and invests in those who continue to raise the bar. Radiant’s new hire compensation package includes base salary, substantial equity grants, and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance, experience, education, and qualifications, and are designed to support continued growth as scope, responsibility, and impact expand at Radiant.

The best of today’s advanced reactor builders don’t wait for job postings. They join the winning team. If that’s you, contact us directly for immediate opportunities: recruiting@radiantnuclear.com.

We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity or expression, pregnancy, age, national origin, disability status, genetic information, protected veteran status, or any other characteristic protected by law.

This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicant’s capacity to serve in compliance with U.S. export controls.

Explore what’s next at Radiant.

Apply for this role

At a glance

Location
El Segundo, CA · El Segundo, California, United States
Workplace
On-site
Employment
Full-time
Team
Engineering
Compensation
$105K – $130K • Offers Equity
Apply for this role

You’ll be taken to Radiant to apply.

The company

Radiant

Radiant

Radiant develops a portable and zero-emissions power source that works anywhere. Its patented portable nuclear microreactor is the brainchild of former SpaceX engineers who have experience quickly bringing real products and innovations to the market. Radiant can offer a low-cost, portable renewable power source that can be an alternative to fossil fuels for both military and commercial applications.

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