Senior Mechanical Engineer, Mechanisms Hardware

Senior Mechanical Engineer, Mechanisms Lead the mechanical mechanisms design for Kaleidos, delivering reliable actuation and safety features. Location: El Segundo, California, United States Compensation: $133,500 - 184,800 USD / year Job Tags: Hardware About The Role 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. Responsibilities & Duties Ownership of critical mechanisms such as the control blade actuator or air jacket valves. Conduct trade studies and develop designs to meet program requirements. Perform detailed thermomechanical analysis (static strength, durability/fatigue) and kinematic analysis to determine structural integrity and performance margins 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 or Aeronautical Engineering. 4+ years of experience designing mechanisms. 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 designing pneumatic systems. Experience integrating electromechanical components such as motors or encoders. 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. #J-18808-Ljbffr Frontdoor Defense