Radiant · 17 hours ago
Thermal Modeling Engineer
El Segundo, CA
Full-time
Onsite
Mid Level
3+ years expRadiant is an El Segundo-based startup building the world’s first mass-produced, portable nuclear microreactors. They are seeking a driven Thermal Modeling Engineer to design, develop, and implement simulations for their Kaleidos microreactor, ensuring high fidelity, reliability, and safety of their systems.
Clean EnergyEnergyEnergy EfficiencyRenewable Energy
No H1B
Responsibilities
Develop and execute thermal analysis and CFD to evaluate design and performance of Kaleidos systems
Document analysis results to communicate clear and actionable outputs
Expand CFD capabilities, accuracy, and efficiencies via methods and workflow development projects
Own pipeline for producing analysis geometry from mechanical design CAD
Develop methods and calculations to support and build confidence in lower-fidelity thermal analysis methods
Qualification
Required
Bachelor's degree in engineering, physics, or similar field from an accredited institution
3+ years experience with Star CCM+ or Ansys Fluent
Proficiency with CAD software (Siemens NX)
Strong understanding of finite element and computational fluid dynamics modeling principles and methods
Experience communicating and distilling information with cross-functional teams
Must be willing to work extended hours and weekends as necessary to accomplish our mission
Must work 100% onsite at El Segundo HQ
Preferred
Experience with radiation heat transport modeling
Knowledge of nuclear reactor design
Driven, self-motivated, and takes ownership of work end to end
Benefits
Substantial incentive stock plan for all full-time employees.
100% premium coverage for base Silver level plan for employee + 50% premium coverage for dependents. Platinum plans available.
Sponsored memberships for eligible employees and their dependents.
100% premium coverage for top tier plan + 50% for dependents.
100% premium coverage for top tier plan (including orthodontia) + 50% for dependents.
Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.
8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.
Daily catered lunch. Free snacks and drinks.
Flexible PTO policy. Remote workday allocation.
Company and team-bonding events, happy hours and in-person camaraderie.
Beautiful El Segundo headquarters close to the Pacific Ocean.
Company
Radiant
Radiant develops portable nuclear microreactors designed to generate electricity and heat in a compact, factory-built form.
51-200 employees
Funding
Current Stage
Late StageTotal Funding
$518.82MKey Investors
Andreessen HorowitzUnion Square Ventures
2025-12-17Series D· $300M
2024-11-14Series C· $165M
2023-04-18Series B· $40M
Leadership Team
Doug Bernauer
Chief Executive Officer
Recent News
2026-01-07
The Motley Fool
2026-01-04
Globe and Mail
2026-01-03
Company data provided by crunchbase