Senior Power Systems Engineer

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 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. Radiant’s 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.

Radiant is seeking a talented Senior Power Systems Engineer to lead the design, modeling, and validation of electrical power systems supporting our nuclear microreactor platform. You will play a critical role in defining how power is generated, conditioned, controlled, and delivered to customers across grid-connected, islanded, and rapidly deployable environments.

In this role, you will own power system studies from early architecture tradeoffs through detailed modeling, testing, and system validation. You’ll collaborate closely with electrical design, controls, turbomachinery, nuclear, thermal, and software teams to ensure safe, stable, and reliable power delivery under a wide range of operating and contingency conditions. This role is central to commercializing Earth’s first mass-produced portable nuclear reactors.

Responsibilities and Duties:

• Own power system modeling and analysis for microreactor-based power generation systems operating in grid-connected and islanded modes


• Develop and maintain steady-state, dynamic, and EMT models representing generation assets, loads, protection schemes, and supervisory controls


• Perform power flow, fault, protection coordination, and system stability studies to validate performance across normal and contingency conditions


• Evaluate system behavior during disturbances such as load steps, faults, breaker operations, and loss-of-generation events.


• Support design trade studies to optimize power system architecture, control strategies, and equipment selection


• Collaborate cross-functionally to align power system models with electrical hardware design, control logic, communication delays, and protection schemes


• Participate in software-in-the-loop (SIL), hardware-in-the-loop (HIL), and system-level testing to validate model fidelity and control performance


• Support system commissioning, troubleshooting, and post-test analysis through data review and model correlation


• Document analyses, assumptions, and results to support internal requirements, customer needs, and regulatory and licensing activities

Required Skills and Qualifications:

• B.S. in Electrical Engineering with an emphasis in power systems or control systems


• 5+ years of experience performing power system analysis 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 inverter-based resources, rotating generation, and power system control modes (grid-forming, grid-following, droop control)


• Experience 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 Skills and Qualifications:

• M.S. in Electrical Engineering or related discipline


• Experience with islanded or weak-grid power systems supporting critical loads


• Familiarity with interconnection requirements, grid codes, and relevant IEEE or utility standards


• Experience 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

Additional Requirements:

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


• Must work 100% onsite at Radiant’s El Segundo headquarters

Total Compensation and Benefits

Radiant's new hire compensation package includes base salary, substantial equity grants, and comprehensive benefits. Total compensation and level are determined through a holistic evaluation of your interview performance, experience, education, and qualifications. 

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 applicant’s capacity to serve in compliance with U.S. export controls.