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Radiant is building the world's first mass-produced, portable nuclear microreactors. The Kaleidos reactor is a 1-megawatt, fail-safe microreactor designed for rapid deployment to hospitals, data centers, remote sites, and military bases, capable of running up to 5 years without refueling. The company is on track to test its first reactor at Idaho National Laboratory in summer 2026, with initial customer deliveries in 2028.
As Senior Mechanical Engineer (Structures), you will own the design and development of critical structural systems within Kaleidos, including mass-efficient transportable shielding, container systems, and high-temperature graphite and metallic structures. You will tackle unique engineering challenges in extreme temperature environments while meeting strict volumetric constraints.
Key responsibilities include: conducting trade studies and developing designs to meet program requirements; performing detailed thermomechanical analysis (static strength, durability, fatigue) and dynamic analysis (vibration, shock) using hand calculations and finite element tools (Abaqus, Ansys, FEMAP); developing manufacturing and assembly instructions and test plans; creating and managing Bills-of-Materials; identifying and developing component suppliers; owning subassembly design, manufacturing, and test schedules; conducting FMEA risk analysis for subsystems; and collaborating with cross-functional teams.
Required: Bachelor's degree in Mechanical, Aeronautical, Civil, or Structural Engineering; 6+ years designing structures; 4+ years performing stress analysis with both hand calculations and FEA tools. Desired: CAD experience (NX or similar), hardware design-to-deployment experience, thermal expansion expertise, GD&T proficiency, text-based software development tool familiarity, and strong communication skills.
This is a 100% onsite role at El Segundo headquarters. Radiant offers substantial equity, comprehensive health benefits, 8 weeks paid parental leave, daily catered lunch, flexible PTO, and team events. The role requires willingness to work extended hours and weekends as needed.
