Radiant
Nuclear Energy
MechanicalEngineer,FluidSystems-2026NewGraduate
Neural analysis suggests this role is
optimal for Entry candidates.
“Mechanical Engineer, Fluid Systems - 2026 New Graduate at Radiant. Skills: Fluid systems, Thermal analysis, Thermodynamics. Own engineering of fluid systems. Own engineering of fluid components”
What You'll Achieve.
Fuel first commercial reactor by 2026
Industry & Context.
Trade studies; Optimization
Export controls compliance
What They're Looking For.
Must Have
Bachelor's degree in Mechanical, Materials, Aeronautical, Civil or Structural Engineering, Experience with fluid system architecture design, Experience in designing, building, and testing fluids systems, Proficient knowledge in fluid dynamics and thermodynamics, Proficient knowledge of heat exchanger design and analysis methods
Nice to Have
Knowledge of thermodynamic power cycles, Prior experience with fluid system modeling via Matlab/Python, Experienced in design for manufacturability, Experienced in ramping up hardware build in production, Experienced in designing and operating test stands, Prior nuclear experience
What You'll Do.
Own engineering of fluid systems
Own engineering of fluid components
Perform thermal analysis
Perform fluids analysis
Drive design decisions
Verify system performance
Ensure structural integrity
Perform trade studies
Optimize system design
Meet program requirements
Develop manufacturing instructions
Develop assembly instructions
Create Bill-Of-Materials
Manage Bill-Of-Materials
Own subassembly design
Own subassembly manufacturing
Own subassembly test schedules
Provide expertise to engineers
Provide feedback to engineers
How You'll Work.
Team & Collaboration
Multidisciplinary teams; Functional areas
Communication Scope
Clear communication; Constructive communication
Process & Methodology
Schedule management
Full Job Description
ABOUT RADIANT 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. ABOUT THE ROLE Radiant is seeking a highly motivated Mechanical Engineer, Fluids Systems to help own critical Kaleidos fluid systems from preliminary design through build and production. These systems include the primary loop subsystems and power conversion loop, serving to convert heat from the reactor core into electrical power. You will be responsible for the following: trade studies, component selection, thermal hydraulic analysis, piping design, vendor selection, assembly, and testing. You will have an instrumental impact of fueling the first new commercial reactor design in over 50 years by 2026. Responsibilities & Duties: - Help own end-to-end engineering of fluid systems and components, including compressors, valves, and heat exchangers. - Perform thermal and fluids analysis to drive design decisions, verify system performance, and ensure structural integrity using first-principle hand calculations and finite element tools. - Perform trade studies to optimize system and meet program requirements. - Develop and execute manufacturing/assembly instructions and test plans. - Create and manage a Bill-Of-Materials (BOM). -
Applying for this Mechanical Engineer, Fluid Systems - 2026 New Graduate role?
Most applicants get filtered before a human reads their resume. See if yours makes the cut.
How to Apply on Ashby
- Ashby is a fast modern ATS — most applications take under 3 minutes.
- The resume parser is strong; verify parsed experience dates and job titles.
- Custom screening questions are often scored algorithmically — answer completely.
- Location field affects geo-based screening; use your actual metro area.
ANONYMOUS · UNFILTERED
What do employees actually say about Radiant?
Real rants from real employees. Read before you apply.