Staff Mechanical Engineer – Fluid Systems

About the role

Radiant, a startup developing portable nuclear micro‑reactors, is looking for a Staff Mechanical Engineer to lead the design, development and production of the fluid systems that transfer heat from the reactor core to the power conversion loop. The role covers the full lifecycle from concept studies through testing and delivery.

Key responsibilities

• Own end‑to‑end engineering of primary and power‑conversion fluid loops, including compressors, valves and heat exchangers.
• Conduct thermal‑hydraulic and fluid dynamics analyses using hand calculations and finite‑element tools.
• Perform trade studies and component selection to meet performance, safety and cost targets.
• Develop detailed piping and sub‑assembly designs, manufacturing instructions and test plans.
• Create and manage the Bill‑of‑Materials and drive supplier selection and qualification.
• Lead risk assessments (FMEA) and schedule sub‑assembly build and test activities.
• Collaborate with cross‑functional engineers to integrate fluid‑system requirements.

Required profile

• Bachelor’s degree in Mechanical, Materials, Aeronautical, Civil or Structural Engineering.
• 7+ years of experience designing, building and testing fluid systems.
• Strong knowledge of fluid dynamics, thermodynamics and heat‑exchanger design.
• Proficiency with hand calculations and finite‑element analysis for thermal and structural evaluation.
• Experience creating BOMs, conducting FMEA and managing supplier relationships.

Required skills

• Thermal‑hydraulic analysis
• Fluid dynamics
• Thermodynamics
• Heat exchanger design and analysis
• Piping design and layout
• Finite‑element analysis (FEA)
• Hand calculations for thermal growth
• Bill‑of‑Materials (BOM) management
• Risk analysis (FMEA)
• Compressor and valve selection