Senior Thermal Engineer – CFD & Thermal FEA Specialist

About the role

Radiant is developing the world’s first mass‑produced portable nuclear microreactor. We are looking for a Senior Thermal Engineer to lead CFD and thermal FEA simulations for our 1‑MW Kaleidos reactor, ensuring high‑fidelity thermal performance and safety across the system.

Key responsibilities

• Lead thermal CFD analyses to evaluate design and performance of reactor, cooling, and shielding systems.
• Develop and implement models for turbulent flow, heat transfer, and multi‑physics interactions.
• Define and apply best‑practice CFD simulation standards.
• Create automated workflows that improve simulation accuracy, speed, and repeatability.
• Collaborate with cross‑functional teams to support reduced‑order analysis and design decisions.

Required profile

• Bachelor’s degree in engineering, physics, or a related field.
• At least 5 years of industry experience in thermal analysis.
• 5 + years of hands‑on experience with commercial CFD tools such as STAR‑CCM+ or ANSYS Fluent.
• Proficiency with Siemens NX or comparable CAD software.
• Strong understanding of finite‑element and CFD modeling principles.
• Proven ability to communicate technical results to multidisciplinary teams.

Required skills

• STAR‑CCM+
• ANSYS Fluent
• Computational Fluid Dynamics (CFD)
• Thermal finite‑element analysis
• Siemens NX CAD
• Turbulent flow and heat‑transfer modeling
• Multi‑physics simulation
• Automated workflow development

What we offer

• Substantial incentive stock plan for all full‑time employees.
• Comprehensive medical coverage (100 % employee, 50 % dependents) with options up to Platinum.
• Sponsored One Medical membership for employees and families.
• Opportunity to work on pioneering nuclear technology in a fast‑growing startup.