Mechanical Engineer

Radiant is an El Segundo CA-based startup building the worlds first mass-produced portable nuclear microreactors. The companys first reactor Kaleidos is a 1-megawatt failsafe microreactor that can be transported anywhere power is needed and run for up to five years without the need to refuel. 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. Radiants unique practical approach to nuclear development utilizes modern software engineering to rapidly achieve safe factory-built microreactors that leverage existing well-qualified materials. Founded in 2020 Radiant is on track to test its first reactor next year at the Idaho National Laboratory with initial customer deliveries beginning in 2028.

Mechanical Engineer

Radiant is seeking a highly motivated Mechanical Engineer to join the team responsible for the design development and integration of critical mechanical systems for our Kaleidos product. This role involves hands-on mechanical design and analysis of complex hardware operating in demanding environments. The ideal candidate has strong first-principles understanding of structures materials fluids and thermodynamics and enjoys taking designs from concept through testing and production. Hands-on engineering experience through internships co-op programs research projects or team-based design competitions (e.g. SAE ASME Formula SAE) is a strong advantage.

Responsibilities and Duties

• Design build and test mechanical components and systems supporting Radiants power generation and cooling platforms.
• Develop detailed mechanical designs for components and assemblies including structural parts housings rotating or moving elements and interfaces.
• Perform static and dynamic structural analyses using hand calculations and FEA tools (ANSYS Abaqus or equivalent) to evaluate stresses deformations and fatigue life.
• Prepare technical reports design documentation and presentation materials to support design reviews and decision-making.
• Support the build assembly and testing of prototype first-article and production hardware.

Required Qualifications and Skills

• Bachelors or Masters degree in Mechanical Engineering or a related field.
• 2 years of experience in mechanical design and analysis of hardware components or mechanical systems.
• Proficiency in CAD and FEA tools (SolidWorks ANSYS Abaqus or equivalent) including working knowledge of GD&T.
• Strong problem-solving skills and the ability to clearly communicate technical concepts.

Desired Qualifications and Skills

• Experience supporting power energy or industrial systems.
• Knowledge of material selection for high-temperature high-load or demanding operating environments.
• Hands-on experience with mechanical testing instrumentation or experimental validation.
• Exposure to one or more mechanical engineering focus areas such as structures mechanisms heat transfer or dynamics.
• Familiarity with relevant industry standards (ASME ISO API or similar).
• Prior nuclear experience is not required for this role.

Additional Requirements

• Willingness to work extended hours and weekends as necessary to accomplish our mission.
• Ability to work 100% onsite at Radiants El Segundo headquarters.

Total Compensation and Benefits
Radiant compensates people for impact and invests in those who continue to raise the bar. Radiants 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 todays advanced reactor builders dont wait for job postings. They join the winning team. If thats you contact us directly for immediate opportunities: .

Benefits and Perks for Eligible Employees:

• Stock: Substantial incentive stock plan for all full-time employees.
• Medical: 100% premium coverage for base Silver level plan for employee 50% premium coverage for dependents. Platinum plans available.
• One Medical: Sponsored memberships for eligible employees and their dependents.
• Vision: 100% premium coverage for top tier plan 50% for dependents.
• Dental: 100% premium coverage for top tier plan (including orthodontia) 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.

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.

Unfortunately we are unable to provide visa sponsorship at this time.

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