Senior Mechanical Engineer

El Segundo, CA

Radiant Industries is an El Segundo, CA-based startup developing Kaleidos, a portable, containerized nuclear microreactor. Portable nuclear power with rapid deploy capability can replace diesel generators used today to provide critical asset support for hospitals, datacenters, and military bases or to power microgrids at remote sites. Radiant’s unique yet practical approach to nuclear development utilizes modern software engineering to rapidly achieve safe, factory-constructable microreactors leveraging existing, well-qualified materials. Radiant is on a fast track to demonstrate the first fueled operation of a new commercial nuclear reactor design, just four years from now.

Radiant is seeking a highly motivated senior mechanical engineer to develop new hardware with a team of experienced engineering professionals in a fast-paced startup environment.  The candidate will be responsible for design and analysis of a wide variety of components in support of developing Kaleidos.

Responsibilities & Duties

  • Mechanical Engineering ownership of components and subsystems, such as the following:
    • Reactor core pressure vessel design per Boiler & Pressure Vessel Code (BPVC)
    • Reactor internal components and mechanisms
    • Radiation shielding and thermal insulation
    • Heat exchangers and other fluid system components
    • Transportation and assembly tooling
  • Perform detailed thermal and mechanical analysis (static strength, durability/fatigue) to determine structural integrity (margins of safety) using both hand calculations and finite element tools.
  • Perform trade studies to optimize structure and meet program requirements.
  • Develop and execute manufacturing/assembly instructions and test plans.
  • Create and manage a Bill-Of-Materials (BOM).
    • Find and develop suppliers for all components
    • Own subassembly design, manufacturing, and test schedules
  • Own risk analysis (FMEA) for subsystems
  • Collect requirements, provide expertise and feedback to engineers in other functional areas via clear, constructive communication.

Required Qualifications & Skills

  • Bachelor’s degree from an accredited institution in Mechanical, Aeronautical, Civil or Structural Engineering.
  • 3+ years of experience performing stress analysis (static and fatigue) using both hand calculations and finite element tools (ANSYS or similar).

Desired Qualifications & Skills

  • 3+ years of experience with design of multi-component assemblies in CAD (Solidworks or similar)
  • 3+ years of professional experience designing hardware that was manufactured, deployed, and iteratively improved.
  • Solid understanding and application of geometric dimensioning and tolerancing (GD&T)
  • Solid first-principles analysis skillset:
    • Proficiency with both “hand calc” analytical methods and higher fidelity Finite Element based analysis methods. Track record of appropriate fidelity selection, based on engineering questions to be answered
  • Ability to derive free-body diagram and control volume-based models for systems with which one was not previously familiar. 
  • Ability to relocate to Radiant’s office in El Segundo, CA (Greater Los Angeles Area)
  • Ability to work or gain permission to work on export - controlled technologies based in the United States.
  • Master’s degree from an accredited institution in Mechanical, Aeronautical, Civil or Structural Engineering.
  • Experience performing CFD analysis for combined fluid/thermal modeling of systems.
  • Experience performing fracture analysis using NASGRO / NASFLA.
  • Experience performing combined structural and thermal analysis of graphite and ceramic structural components.
  • Self-motivated with strong organizational, written, and oral communication skills.
  • Experience with using text-based software development tools.
    • Python or C# development experience preferred.
    • Use of code repositories, unit testing, performance benchmarking, and software release processes.
    • Familiarity with good documentation practices and implementation of style guidelines.


Stock: Substantial incentive stock plan for all salaried employees

Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.

Vision: 100% coverage + 50% for dependents

Dental: 100% coverage, orthodontia extra, 50% for dependents

Voluntary Life, Accident, Hospital, Critical Illness, Commuter and FSA are offered as employee contributed benefits.

Vacation/Sick time

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.