Lead Test Engineer, Power Generation

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.

Radiant is seeking aLead Test Engineer Power Generationto own the strategy execution and team leadership for testing the power generation system including turbomachinery heat exchangers controls and primary cooling systems. This role is ideal for a hands-on technical leader who enjoys building test infrastructure running complex hardware and mentoring engineers and technicians whileremainingdeeply involved in day-to-day testing.

You will lead testing development for our high-speed machinery and own creating our test site from the ground test infrastructure will be used to iterate quickly on our designs evaluating vibration performance thermal behavior and system reliability in development and transition into acceptance testing for production units. This role works closely with mechanical design analysis manufacturing and operations teams to ensure turbomachinery designs arevalidated robust andproduction-ready.

Responsibilities

Test Site & Infrastructure Development

• Lead requirements definition design and implementation ofRadiantstest site
• Design build commission andmaintaintest rigs fixturesinstrumentationand support systems forturbomachinery heat exchangers controls and primary cooling systems
• Establish operating procedures safety controls and facility readiness for high-speed high-energy and high-temperature test environments

Test Strategy Planning & Technical Ownership

• Own and lead the turbomachinery test strategy across development qualification and production acceptance phases
• Define testobjectives plans success criteria instrumentation strategies and data requirements for high-speed rotating machinery and supporting thermal-fluid systems
• Serve as the technical authority for vibrationrotordynamic and bearing-related testing
• Translate analytical predictions (critical speeds stability margins transient response) into targeted test campaigns thatvalidatedesign assumptions and retire risk.
• Balance test coverage technical risk schedule and hardware availability to enable rapid iteration whilemaintainingsafety and rigor

Test Execution & Data Analysis

• Plan and execute development qualification and acceptance tests including startup/shutdown transient off-design and endurance testing
• Operate test hardware hands-on with a strong emphasis on repeatability data quality and safety
• Analyze test data to assess vibration behaviorrotordynamicstability bearing performance thermal response and overall system performance
• Compare test results against analytical predictions and work with design teams to resolve discrepancies
• Collaborate with mechanical engineers to conduct root cause investigations identify anomalies or failures and implement corrective actions supported by test evidence

Technical Leadership & Team Development

• Provide technical leadership and mentorship to test engineers and technicians
• Act as a player-coach: remain hands-on while scaling testing capability throughput and organizational maturity
• Support hiring onboarding and technical development of turbomachinery test personnel
• Develop work estimates test schedules and status updates for program leadership
• Review and approve test procedures reports and data packages
• Establish standards for test documentation data management and knowledge capture
• Help matureRadiantsturbomachinery test processes labs and safety culture over time

Cross-Functional Collaboration

• Partner closely with turbomachinery mechanical engineers to ensure designs are testable and adequatelyvalidated
• Reviewcomponentand system-level design documentation with an eye toward test coverage instrumentation and risk
• Collaborate with thermal manufacturing quality and operations teams to support prototype first-article and production hardware testing
• Represent testing in design reviews test readiness reviews and technical leadership discussions

Required Qualifications

• Bachelors orMasters degree in Mechanical Engineeringor a related field or equivalent experience
• 8 years of experience in testing development or validation of turbomachinery rotating equipment or complex mechanical systems
• Hands-on experience testing high-speed rotating machinery and high-temperature hardware
• Experience correlating test results with analytical predictions and design intent
• Demonstrated technical leadership and ability to drive complex test efforts to completion
• Strong written verbal and organizational skills

Desired Qualifications

• Prior experience leading or mentoring test engineers or technicians
• Experience with power generation or otherhigh-reliabilitypower generationsystems
• Strong understanding ofrotordynamics vibration and bearing behavior as applied to real hardware testing
• Familiarity withrotordynamicanalysis tools ( or equivalent) from a test correlation or validation perspective
• Familiarity with relevant industry standards (API ASME ISO)
• Startup or fast-paced hardware development experience
• Prior nuclear experience is notrequired

Additional Requirements

• Willingness to work extended hours or weekends as necessary to accomplish program objectives
• Must 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.
• Burgeoning satellite offices in Oak Ridge TN and Washington D.C. near Capitol Hill.

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.