Thermal-Hydraulics and Safety Analysis Engineer (Nuclear)

Location: Santa Clara, California, or remote within the United States. Remote employees must travel to the Santa Clara headquarters twice per quarter based on business or team needs, and must work onsite there for the first two weeks of onboarding. Applicants must meet the definition of a U.S. person under applicable export control laws.

Salary: $150,000–$200,000 per year, depending on experience.

Company

hirify.global develops fast fission power plants, domestic radioisotope supply chains, and nuclear fuel recycling technologies.

What you will do

• Develop, maintain, and execute systems-level thermal-hydraulic models of reactor and plant behavior using RELAP5 or comparable tools.
• Analyze normal operation, anticipated operational occurrences, design-basis events, and selected beyond-design-basis conditions.
• Define event-specific analysis plans, initial and boundary conditions, acceptance criteria, figures of merit, and uncertainty treatments.
• Develop thermal-hydraulic safety-analysis methods, modeling guidance, and engineering practices for advanced reactor licensing.
• Perform verification, validation, sensitivity, uncertainty, scaling, bias, and code-applicability assessments using experiments, benchmarks, hand calculations, and higher-fidelity analyses.
• Prepare calculation packages, methodology documents, safety-analysis reports, licensing content, regulator responses, automated workflows, and technical reviews.

Requirements

• Bachelor’s, master’s, or doctoral degree in nuclear, mechanical, chemical, aerospace engineering, or a related technical field.
• Five or more years of relevant experience in reactor thermal-hydraulics, nuclear safety analysis, reactor transient analysis, or a related field.
• Demonstrated experience developing and executing systems-level transient models using RELAP5.
• Strong knowledge of heat transfer, fluid mechanics, thermodynamics, reactor thermal-hydraulics, transient scenarios, and accident analysis.
• Experience assessing model and correlation applicability, uncertainty, sensitivity, scaling, verification, and validation rather than treating software as a black box.
• Must be eligible as a U.S. person under applicable U.S. export control laws. Ability to work independently and collaborate across engineering and licensing disciplines is required.

Nice to have

• Experience with NRC or DOE licensing applications, audits, methodology reports, regulator questions, or other regulatory interactions.
• Fluency with Python or another language for model automation, data analysis, visualization, and quality checks.
• Experience with version control, automated testing, reproducible computing, continuous integration, nuclear quality assurance, or safety-related software.
• Experience mentoring analysts or technically reviewing safety-analysis work.

Culture & Benefits

• Fast-paced, iterative startup environment with substantial independence and open-ended technical problem-solving.
• Collaborative work across safety, licensing, design, reactor physics, controls, and other engineering disciplines.
• Flexible time off, flexible work hours, equity, bonuses, and competitive pay.
• 401(k), health insurance with employer contribution, HSA, FSA, and wellness credits.
• Remote work is supported with required headquarters travel and onsite onboarding in Santa Clara.

Hiring process

• Employment may be contingent on successful completion of a drug screening.
• Employees may be subject to drug testing in accordance with company policy and applicable laws.