Principal Electrical Engineer, Integration & Test

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 Principal Electrical Engineer to lead the electrical system architecture and test infrastructure for Kaleidos, Radiant's commercial microreactor unit targeted for deployment in 2028. You will own end-to-end electrical integration, from early architecture and requirements definition through hardware bring-up, testing, and commissioning, and serve as the technical authority, ensuring the electrical and validation systems are ready to support that milestone.

The ideal candidate brings deep electrical engineering expertise, strong systems-level thinking, and a track record of leading complex hardware programs from concept to deployment. You are equally comfortable making architecture decisions independently and collaborating across mechanical, software, and systems engineering teams.

• Define and own electrical and software integration requirements spanning power distribution, signal conditioning, sensor mapping, actuator interfaces, and device simulation.

• Own and build out the electrical test infrastructure for Kaleidos, and establish the test environment as a foundational asset to validate the commercial unit ahead of the 2028 deployment target.

• Establish and maintain communication between hardware, control systems, and software interfaces.

• Define and drive electrical validation strategy; develop test procedures, methodologies, and best practices.

• Manage schedule, budget, and vendor management for electrical hardware and integration activities.

• Optimize test and validation processes; develop tooling and automation to improve efficiency.

• Support electrical integration across multiple critical systems and subsystems.

• Lead design reviews and effectively communicate technical decisions to cross-functional stakeholders. (Electrical integration, embedded, software, controls.)

• BS in Electrical Engineering or related discipline from an accredited institution.

• 10+ years of progressive electrical engineering experience, including hands-on hardware design, integration, and test.

• Demonstrated experience setting technical direction, mentoring engineers, and driving programs with significant scope and ambiguity.

• Demonstrated ability to work under tight timelines and deliver a functional product that meets requirements.

• Experience with DAQ and test systems (e.g., NI PXI, dSpace, Speedgoat, or similar platforms).

• Proficiency with software and scripting environments (e.g., LabVIEW, TestStand)

• Proficiency with data acquisition systems, test execution, and validation frameworks.

• Strong electrical and software debugging and root cause analysis skills.

• Experience working cross-functionally with software, mechanical, and systems engineering teams.

• Proficiency in at least one scripting or programming language (Python, C++, C#, or similar).

• MS or PhD in Electrical Engineering, or a related discipline.

• Familiarity with real-time simulation systems and/or FPGA-based hardware.

• Experience with controls fundamentals and software testing processes.

• Hands-on experience with trace capture, data acquisition, and analysis tools.

• Background in high-reliability, safety-critical, or regulated industry environments (aerospace, defense, nuclear, medical, or automotive)

• 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: [email protected].
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.