Principal Turbomachinery Engineer

Radiant is seeking a Principal Turbomachinery Engineer to serve as the Responsible Engineer for the turbomachinery within our nuclear-driven power generation system. This role owns the mechanical design integrity and performance of the core rotating assembly at the heart of our 1MW closed-loop Brayton cycle.

You will define and drive the mechanical architecture of high-speed rotating hardware operating at extreme temperatures pressures and rotational speeds. As a deeply technical individual contributor you will set direction for rotor dynamics structures bearings seals and system integration while working closely with electrical thermal and manufacturing teams.

This is a hands-on high-ownership role focused on technical excellence sound engineering judgment and delivering reliable production-ready turbomachinery.

Responsibilities

Technical Ownership & System Architecture

• Serve as Responsible Engineer for the turbomachinery mechanical system

• Own the mechanical architecture and design strategy for high-speed rotating assemblies (up to 30 krpm)

• Lead rotor dynamics structural integrity and life analysis for rotating components and assemblies

• Define and flow down requirements from system-level constraints including thermal structural and operational environments

• Make key technical decisions on rotor layout shafting bearings seals materials and clearances

• Ensure designs meet performance reliability safety and regulatory requirements

• Establish and uphold standards for mechanical design rigor analysis quality and documentation

Mechanical Design & Analysis

• Lead detailed design of turbomachinery components including rotors shafts housings and support structures

• Test and validate rotordynamic systems driving model correlation risk reduction and performance verification

• Perform and review structural and thermal analysis to ensure integrity under high-speed and high-temperature operation

• Define tolerances fits stack-ups and alignment strategies for precision rotating assemblies

• Partner with electrical engineering on alternator rotor integration including electromagnetic and structural coupling

Cross-Functional Integration

• Partner closely with turbomachinery aero motor design thermal manufacturing and test teams

• Ensure seamless integration between turbine compressor and alternator subsystems

• Drive clear interface definitions across mechanical electrical and thermal boundaries

• Collaborate with manufacturing to ensure designs are producible inspectable and scalable

• Engage with suppliers on technically critical components and design decisions

Prototyping Testing & Validation

• Support assembly integration and test of turbomachinery hardware

• Define validation strategies including spin testing thermal testing and system-level operation

• Lead root cause analysis and drive design iteration for test failures or performance gaps

• Remain hands-on in hardware bring-up troubleshooting and refinement

Technical Influence

• Act as a subject matter expert in turbomachinery mechanical design and rotating systems

• Provide technical guidance and design reviews across the team without direct people management responsibility

• Influence engineering direction through deep expertise data-driven decisions and strong judgment

• Contribute to technical roadmap risk identification and mitigation strategies

Required Qualifications

• B.S. in Mechanical Engineering or related field

• 8 years of experience designing high-speed rotating machinery (turbines compressors or similar systems)

• Deep expertise in structural analysis and mechanical design of turbomachinery

• Experience with bearings seals and high-speed shafting design

• Expert-level proficiency with analysis tools (e.g. ANSYS) and advanced use of NX and Teamcenter for complex design simulation and product lifecycle management

• Strong understanding of tolerancing GD&T and precision mechanical assembly

• Experience owning hardware through design build and test cycles

• Hands-on experience with assembly integration and troubleshooting of turbomachinery

• Strong system-level thinking and mechanical intuition

• Excellent engineering judgment and decision-making capability

• Ability to influence without authority across cross-functional teams

• Clear communicator capable of articulating complex technical concepts

• High ownership mindset and accountability for hardware outcomes

• Ability to operate effectively in a fast-paced first-of-a-kind development environment

Preferred Qualifications

• 10 years of turbomachinery or rotating equipment experience

• M.S. or Ph.D. in Mechanical Engineering

• Experience with closed-loop Brayton cycle systems or similar energy systems

• Familiarity with high-temperature materials and extreme environment design

• Experience integrating mechanical systems with high-speed electric machines

• Prior experience as a Responsible Engineer for complex hardware

• Experience scaling hardware from prototype to production

Additional Requirements

• Must be willing to work extended hours and weekends as necessary to accomplish our mission

• Must work 100% onsite at El Segundo HQ

Benefits and Perks

• Stock: Substantial incentive stock plan for all full-time employees.

• Medical: 100% up to base silver level plan for employee 50% dependents offers up to Platinum plans.

• One Medical: Sponsored memberships for employees and their dependents.

• Vision: 100% top tier plan coverage 50% for dependents.

• Dental: 100% top tier plan coverage orthodontia extra 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.

Total Compensation and Benefits
Radiant compensates people for impact and invests in those who continue to raise the bar. Radiants new hire compensation package includes base salary substantial equity grants and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance experience education and qualifications and are designed to support continued growth as scope responsibility and impact expand at Radiant.

The best of todays advanced reactor builders dont wait for job postings. They join the winning team. If thats you contact us directly for immediate opportunities: .

We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race color religion sex sexual orientation gender identity or expression pregnancy age national origin disability status genetic information protected veteran status or any other characteristic protected by law.

Unfortunately we are unable to provide visa sponsorship at this time.

This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicants capacity to serve in compliance with U.S. export controls.

Required Experience:

Staff IC