Demo

Senior Mechanical Engineer (Structures)

Radiant
El Segundo, CA Full Time
POSTED ON 4/24/2026
AVAILABLE BEFORE 6/17/2026
Radiant is seeking a highly motivated Senior Mechanical Engineer to design and develop critical structures within Kaleidos. You will solve unique challenges creating efficient and reliable structures that facilitate fission while surviving extreme temperature environments and meeting volumetric constraints. You will be responsible for the following: trade studies, material selection, detailed structural analysis, assembly, integration, and testing. You will have an instrumental impact of fueling the first new commercial reactor design in over 50 years by 2026.

Responsibilities & Duties

  • Ownership of critical structures such as mass-efficient transportable shielding systems, container system, and high temperature graphite and metallic systems.
  • Conduct trade studies and develop designs to meet program requirements.
  • Perform detailed thermomechanical analysis (static strength, durability/fatigue) and dynamic analysis (vibration, shock) to determine structural integrity (margins of safety) using both hand calculations and finite element tools.
  • Develop and execute manufacturing/assembly instructions and test plans.
    • Create and manage a Bill-Of-Materials (BOM).
    • Find and develop suppliers for 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.
  • 6 years of experience designing structures.
  • 4 years of experience performing stress analysis using both hand calculations and finite element tools (Abaqus, Ansys, FEMAP, or similar).

Desired Qualifications & Skills

  • Experience with design of multi-component assemblies in CAD (NX or similar).
  • Experience designing hardware that was manufactured, deployed, and iteratively improved.
  • Experience resolving thermal expansion issues in designs.
  • Experience working with interdisciplinary teams.
  • Solid understanding and application of GD&T.
  • Proficiency with both “hand calc” analytical methods and higher fidelity finite element-based analysis methods.
  • Ability to derive free-body diagrams for systems with which one was not previously familiar.
  • Self-motivated with strong organizational, written, and oral communication skills.
  • Experience with using text-based software development tools.

Additional Requirements

  • Must be willing to work extended hours and weekends as necessary to accomplish our mission.
  • Must work 100% onsite at El Segundo HQ.

Salary.com Estimation for Senior Mechanical Engineer (Structures) in El Segundo, CA
$122,227 to $146,461
If your compensation planning software is too rigid to deploy winning incentive strategies, it’s time to find an adaptable solution. Compensation Planning
Enhance your organization's compensation strategy with salary data sets that HR and team managers can use to pay your staff right. Surveys & Data Sets
Employees: Get a Salary Increase
View Core, Job Family, and Industry Job Skills and Competency Data for more than 15,000 Job Titles Skills Library

Job openings at Radiant

  • Radiant El Segundo, CA
  • Radiant is seeking a highly motivated Senior Structures Engineer to design and develop critical structures within Kaleidos. You will solve unique challenge... more
  • 1 Day Ago

  • Radiant El Segundo, CA
  • About Radiant Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reac... more
  • 1 Day Ago

  • Radiant El Segundo, CA
  • About Radiant is seeking a Supplier Development Engineer responsible for the onboarding, qualification, auditing, and ongoing development of suppliers to e... more
  • 1 Day Ago

  • Radiant El Segundo, CA
  • Radiant is seeking a highly motivated Senior Mechanisms Engineer to design and develop critical mechanisms within Kaleidos. You will solve unique challenge... more
  • 1 Day Ago


Not the job you're looking for? Here are some other Senior Mechanical Engineer (Structures) jobs in the El Segundo, CA area that may be a better fit.

  • Apex - Spacecraft Manufacturing Los Angeles, CA
  • Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases... more
  • 16 Days Ago

  • CHAOS Industries Hawthorne, CA
  • CHAOS Industries is redefining modern defense with omniscient systems purpose-built for today’s realities. Designed and built by top U.S. military veterans... more
  • 16 Days Ago

AI Assistant is available now!

Feel free to start your new journey!