Advanced Fluid Systems Jobs in California (NOW HIRING)

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 Systems Engineer to develop, maintain, and govern engineering design standards, requirements, and verification methodologies for the mass production of nuclear reactors. This role bridges systems engineering, design, analysis, manufacturing, and operations. As a Systems Engineer, you will be responsible for ensuring that hardware and concepts of operation meet requirements and are designed in accordance with Radiant standards. In short, you’ll be the glue between our analysis, test, certification, and design teams, helping to connect the technical dots and solve problems across our reactor designs.

Responsibilities & Duties:

• Develop, own, and continuously improve design criteria, standards, and requirements for reactor core, structures, fluid systems, electronics, and shielding.

• Provide critical peer review and approval of hardware designs during design reviews; confirm acceptance and qualification test campaigns.

• Engage with Engineering to drive optimized designs while shepherding them through the design review process, verification testing, and part release.

• Guide engineers through the Radiant design process and ensure design criteria/requirements are being followed for reactor design, manufacturing, and test activities.

• Collaborate with responsible engineers throughout the entire design process, ensuring design criteria are properly considered in the development of hardware.

Required Qualifications & Skills:

• Bachelor’s degree in engineering (mechanical, aerospace, systems, or related).

• 2+ years of experience in engineering design, analysis, or systems engineering.

• Experience in manufacturing or production environments.

• Excellent communication and documentation skills.

Desired Qualifications & Skills:

• Advanced degree in an engineering discipline.

• Experience with requirements management tools (e.g., DOORS, Jama, Flow).

• Strong understanding of the system design process including interface control and tradeoffs.

• Familiarity with structural, thermal, and fluid systems.

• 5+ years professional experience in an engineering role (design, analysis, test, or manufacturing.

Additional Requirements:

• Must be willing to work extended hours and weekends as necessary to accomplish our mission.

• Must work 100% onsite at El Segundo HQ.

• 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.

Compensation Range: $133,500 - $190,050