Senior Turbomachinery Engineer

Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt failsafe microreactor that can be transported anywhere power is needed and run for up to five years without the need to refuel. Portable nuclear power with rapid deploy capability can replace similar-sized diesel generators, and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development utilizes modern software engineering to rapidly achieve safe, factory-built microreactors that leverage existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor next year at the Idaho National Laboratory, with initial customer deliveries beginning in 2028.

Senior Turbomachinery Engineer 

Radiant is seeking a highly motivated Turbomachinery Engineer to join our engineering team to own the power generation and/or primary cooling turbomachinery of our Kaleidos product. This role involves performing the mechanical design and analysis of high-speed rotating machinery including compressors, turbines, and pumps for high-temperature applications. The ideal candidate will have a strong background in mechanical design, structural and thermal finite element analysis (FEA), rotordynamic simulations, and bearing selection and integration, along with hands-on experience building physical hardware. 

Responsibilities and Duties:   

• Full ownership of machinery, from architecture down-selection to mass-production design. 
• Develop detailed mechanical designs for turbomachinery components, including rotors, stators, housings, and seals. 
• Perform static and dynamic structural analyses using FEA tools (ANSYS, Abaqus, or equivalent) to assess stresses, deformations, and fatigue life. 
• Conduct thermal analysis to evaluate temperature distributions and thermal stresses under transient and steady-state conditions. 
• Perform rotordynamic modeling and analysis to evaluate critical speeds, mode shapes, unbalance response, and stability. 
• Select appropriate bearing types (e.g., rolling element, fluid film, magnetic) based on operating conditions and performance requirements. Evaluate bearing loads, life, and thermal performance. 
• Prepare technical reports, design documentation, and presentation materials. 
• Oversee the build and testing of prototype, first article, and production hardware.  

Required Qualifications and Skills:  

• Bachelor’s or Master’s degree in Mechanical Engineering or a related field. 
• 5+ years of experience in the design and analysis of turbomachinery, rotating equipment, or mechanisms. 
• Proficiency in CAD and FEA tools (SolidWorks, ANSYS, Abaqus, etc.), including knowledge of GD&T. 
• Excellent problem-solving, technical communication, and organizational skills. 

Desired Qualifications and Skills:   

• Prior experience with supercritical CO2 applications. 
• Strong understanding of rotordynamic principles and tools (e.g., XLrotor, DyRoBeS, or equivalent). 
• Knowledge of material selection for high-temperature, high-speed applications. 
• Hands-on experience with turbomachinery testing and instrumentation. 
• Experience translating broad machinery requirements (power, speed, bearing leakage) into a conceptual design, including wheel and shaft design, as well as bearing and alternator selection. 
• Familiarity with AC power generation and power electronics. 
• Familiarity with relevant industry standards (API, ASME, ISO). 
• Basic programming knowledge (e.g. Python, C++, or equivalent) 
• Prior nuclear experience is not required for this role.   

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. 

Total Compensation and Benefits

Radiant's new hire compensation package includes base salary, substantial equity grants, and comprehensive benefits. Total compensation and level are determined through a holistic evaluation of your interview performance, experience, education, and qualifications. 

Benefits and Perks for Eligible Employees:

• 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.

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 applicant’s capacity to serve in compliance with U.S. export controls.