Principal Thermal Modeling Engineer (Nuclear)

Location: 100% onsite at the El Segundo headquarters, United States; extended hours and weekends may be required as necessary.

Salary: $182,000–$292,950 plus equity.

Company

hirify.global develops mass-produced, transportable nuclear microreactors, including the 1 MW Kaleidos reactor for critical infrastructure and commercial applications.

What you will do

• Serve as the technical authority for thermal CFD and thermal FEA modeling of Kaleidos reactor systems, owning complex and high-risk analyses.
• Define modeling methods and best practices for turbulent flow, heat transfer, and multiphysics interactions.
• Lead model verification and validation against test data, including confidence and uncertainty bounds.
• Architect automated simulation workflows, tooling, and the simulation-infrastructure roadmap.
• Develop reduced-order analysis methods with design, systems, and test teams.
• Influence reactor, cooling, and shielding decisions; mentor engineers, conduct reviews, and contribute to hiring.

Requirements

• Bachelor’s degree in engineering, physics, or a similar field from an accredited institution; an advanced degree is preferred.
• 10+ years of relevant industry experience with technical leadership on complex, high-consequence programs.
• Extensive experience with STAR-CCM+, Ansys Fluent, or other commercial CFD codes, including advanced turbulence and conjugate heat-transfer modeling.
• Mastery of finite element and computational fluid dynamics principles, with experience validating models against test data.
• Proficiency with Siemens NX or comparable CAD software.
• Experience building automated simulation workflows and scripting tools.
• Ability to mentor engineers and communicate complex technical results to cross-functional teams and leadership.
• Must work 100% onsite at El Segundo HQ and be willing to work extended hours and weekends when necessary.

Nice to have

• Experience with radiation heat-transport modeling.
• Knowledge of nuclear reactor design, thermal-hydraulics, or safety analysis.
• Experience with thermal-structural or neutronics-thermal multiphysics coupling.
• Experience with reduced-order modeling or system-level thermal-hydraulic codes.
• Experience with regulatory or safety-basis analysis.
• Aerospace or automotive industry experience; prior nuclear experience is not required.

Culture & Benefits

• Substantial incentive stock plan for full-time employees.
• Medical, vision, dental, life, accident, hospital, critical illness, commuter, FSA, and HSA benefits, with dependent coverage options.
• Paid parental leave, including eight weeks for all parents and additional paid pregnancy leave for California employees.
• Fully covered Nuclear Engineering Certificate Program through Penn State University for eligible employees.
• Flexible PTO, catered lunch, snacks, drinks, team events, and in-person collaboration at the El Segundo headquarters.
• Remote workday allocation is listed among the benefits, but this position requires 100% onsite work.

Hiring process

• Compensation and level are determined through evaluation of interview performance, experience, education, and qualifications.
• Interested candidates may contact recruiting@hirify.globalnuclear.com directly for opportunities.
• Any offer is contingent on the applicant’s capacity to serve in compliance with U.S. export controls.