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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 to test its first reactor at Idaho National Laboratory with initial customer deliveries expected in 2028.
As a Senior Thermal-Hydraulics Engineer, you will own the thermal CFD analysis and modeling for the Kaleidos microreactor, ensuring high fidelity, reliability, and safety across all systems. Your responsibilities include designing and executing CFD simulations to evaluate reactor performance, developing solutions for turbulent flow and heat transfer modeling, identifying and implementing CFD best practices, and building automated workflows to improve simulation capabilities and efficiency. You will collaborate across interdisciplinary teams to support design decisions affecting reactor systems, cooling systems, shielding, and other critical components.
Required qualifications include a bachelor's degree in engineering, physics, or related field; 5+ years of relevant industry experience; 5+ years 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. You must be an excellent communicator who can distill complex information for cross-functional teams.
Desired qualifications include experience with radiation heat transport modeling, knowledge of nuclear reactor design, and a self-motivated, ownership-oriented mindset. The role requires 100% onsite work at the El Segundo headquarters and willingness to work extended hours and weekends as needed to advance the company's mission.
Radiant offers substantial equity grants, comprehensive health benefits (medical, dental, vision), 8 weeks of paid parental leave, daily catered lunch, flexible PTO, and a collaborative team environment near the Pacific Ocean.
