Principal Power Systems Engineer

About the role

Radiant is a startup based in El Segundo, CA, developing the world's first mass-produced, portable nuclear microreactors. Their first reactor, Kaleidos, is a 1-megawatt, fail-safe microreactor capable of running for up to 5 years without refueling. This technology can replace diesel generators and provide critical power to hospitals, data centers, remote sites, and military bases. Radiant uses modern software engineering to rapidly deliver safe, factory-built microreactors using existing materials. The company aims to test its first reactor at the Idaho National Laboratory this summer and begin delivering initial customer units in 2028.

Responsibilities

• Own power system architectural design for microreactor-based power generation systems operating in grid-connected and islanded modes.
• Develop single-line diagrams of the power system for single- or multiple-reactor configurations.
• Develop FMEAs to identify system behavior during component/system failures and identify redundancy paths.
• Evaluate system behavior during disturbances such as load steps, faults, breaker operations, and loss-of-generation events.
• Size energy storage systems for reactor cold start and variable load demands.
• Own synchronization of multiple reactors in a microgrid and multiple reactors tied to grid.
• Collaborate cross-functionally with the power conversion team to understand generator requirements and design power systems that can integrate seamlessly.
• Participate in software-in-the-loop (SIL), hardware-in-the-loop (HIL), and system-level testing to validate/verify system performance.
• Support system checkouts, commissioning, and testing of all power requirements.
• Regulatory compliance of power systems, including testing methods to verify power quality.

Qualifications

• B.S. in Electrical Engineering with an emphasis in power systems or control systems.
• 5+ years of experience designing power systems for generation, microgrids, or mission-critical power systems.
• Experience with sizing and integrating high-voltage battery systems with power electronics.
• Strong experience with power system modeling and simulation tools (e.g., PSCAD, ETAP, PSS®E, Simulink, or equivalent).
• Solid understanding of inverters, grid converters, DC/DC converters, rotating generation, and power system control modes (grid-forming, grid-following, droop control).
• Experience in analyzing system stability, protection behavior, and fault response in complex electrical systems.
• Ability to clearly communicate technical concepts and results to cross-functional teams.

Desired Qualifications

• M.S. in Electrical Engineering or related discipline.
• Experience in power electronics development for high-power, medium-voltage equipment, including transformers, switchgear, inverters, active rectifiers, DC/DC converters, and generator controls.
• Experience with islanded power systems supporting critical loads.
• Familiarity with interconnection requirements, grid codes, and relevant IEEE or utility standards.
• Experience in modeling dynamic loads and fast-changing electrical demand.
• Exposure to nuclear, aerospace, defense, or other highly regulated industries.
• Experience mentoring junior engineers or leading technical efforts on complex programs.

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.
• A 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. The 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: $200,500 - $314,475.