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Radiant is building the world's first mass-produced, portable nuclear microreactors. The company's flagship product, Kaleidos, is a 1-megawatt, fail-safe microreactor designed for rapid deployment to hospitals, data centers, remote sites, and military bases. Founded in 2020, Radiant is preparing for its first reactor test at Idaho National Laboratory with initial customer deliveries planned for 2028.
As Senior Thermal Modeling Engineer, you will own the thermal and CFD analysis for the Kaleidos microreactor, ensuring high fidelity, reliability, and safety across all systems. You'll develop and implement advanced simulations for turbulent flow, heat transfer, and multi-physics interactions in a high-temperature gas reactor environment. Your work will directly inform critical design decisions for reactor systems, cooling, shielding, and more.
Key responsibilities include executing thermal CFD analysis to evaluate reactor design and performance, developing solutions for complex multi-physics modeling, identifying and implementing CFD best practices, building automated workflows to improve simulation capabilities and efficiency, and collaborating across interdisciplinary teams to support design optimization and reduced-order analysis methods.
You'll need a bachelor's degree in engineering, physics, or related field, plus 5+ years of industry experience with commercial CFD codes (STAR-CCM+, Ansys Fluent, or equivalent). Proficiency with CAD software (Siemens NX) and mastery of finite element and computational fluid dynamics principles are required. Experience with radiation heat transport modeling and nuclear reactor design is highly valued. The role requires 100% onsite presence at El Segundo headquarters and willingness to work extended hours as needed to advance commercialization milestones.
