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Radiant is building the world's first mass-produced, portable nuclear microreactors. The company's flagship product, Kaleidos, is a 1-megawatt, fail-safe microreactor designed for rapid deployment to hospitals, data centers, remote sites, and military bases. Founded in 2020, Radiant is preparing to test its first reactor at Idaho National Laboratory with initial customer deliveries expected in 2028.
As Staff Fluid Systems Engineer, you will own the complete engineering lifecycle of Kaleidos fluid systems—from preliminary design through build and production. These critical systems include the primary loop subsystems and power conversion loop, which convert heat from the reactor core into electrical power.
Key responsibilities include:
- End-to-end engineering ownership of fluid systems and components (compressors, valves, heat exchangers)
- Complex thermal and fluids analysis using first-principle calculations and finite element tools to drive design decisions and verify system performance
- Trade studies to optimize system design and meet program requirements
- Development and execution of manufacturing, assembly instructions, and test plans
- Bill-of-Materials (BOM) creation and management
- Supplier identification, evaluation, and development for all components
- Subassembly design, manufacturing, and test schedule ownership
- Risk analysis (FMEA) for subsystems
- Cross-functional collaboration with other engineering teams through clear, constructive communication
You will have instrumental impact on fueling the first new commercial reactor design in over 50 years. The role requires 100% onsite presence at El Segundo headquarters and willingness to work extended hours and weekends as needed.
REQUIREMENTS:
- Bachelor's degree in Mechanical, Materials, Aeronautical, Civil, or Structural Engineering from an accredited institution
- 8+ years of experience designing, building, and testing fluid systems
- Experience with fluid system architecture design
- Proficient knowledge of fluid dynamics and thermodynamics
- Proficient knowledge of heat exchanger design and analysis methods
DESIRED QUALIFICATIONS:
- Knowledge of thermodynamic power cycles
- Prior experience designing piping systems for thermal growth using hand calculations and FEA tools
- Experience with process piping design and testing codes (ASME B31.3, ASME PCC-2)
- Fluid system modeling via Matlab/Python
- Design for manufacturability and hardware production ramp-up experience
- Test stand design and operation experience
- Extreme ownership mentality and high responsibility orientation
- Excellent multidisciplinary team communication
- Prior nuclear experience not required
