Staff Nuclear Engineer (Advanced Reactors)

Location: El Segundo, California, United States. 100% onsite at hirify.global’s El Segundo headquarters.

Salary: $195,713–$262,500 annually, plus equity.

Company

hirify.global is an El Segundo-based company developing mass-produced, transportable nuclear microreactors. Its 1 MW Kaleidos reactor is designed for deployment at military bases, data centers, hospitals, remote sites, and commercial facilities.

What you will do

• Provide technical leadership across reactor physics, core performance, shielding, dose and activation, thermal-hydraulics, safety analysis, instrumentation and controls, and reactor operations.
• Own complex nuclear engineering projects from requirements and design trades through model development, analysis, review, verification and validation, testing, and final documentation.
• Perform and guide criticality, reactivity control, shutdown margin, power distribution, depletion, temperature feedback, radiation transport, dose, activation, and shielding analyses.
• Develop and improve high-fidelity neutron and radiation transport models, analytical methods, workflows, and tools.
• Translate analysis into requirements and design decisions across the core, shielding, controls, fluid systems, structures, and surrounding hardware.
• Collaborate with reactor systems, thermal, mechanical, electrical, test, operations, safety, and regulatory teams; mentor engineers and drive technical risks through closure.

Requirements

• Bachelor’s degree in nuclear engineering or a related technical discipline from an accredited institution.
• 8+ years of relevant nuclear engineering experience across reactor design, analysis, testing, licensing, safety, or operations.
• Experience owning complex nuclear engineering projects involving multiple disciplines and stakeholders, operating independently from definition through technical closure.
• Deep knowledge of neutron transport theory, Monte Carlo simulation, nuclear data, statistical convergence, and reactor physics, including criticality, reactivity coefficients, depletion, power distribution, shutdown margin, neutron and gamma transport, and uncertainty analysis.
• Professional experience developing and applying MCNP, OpenMC, or comparable neutron and radiation transport models.
• Experience translating analytical results into reactor design decisions, technical requirements, safety conclusions, or regulatory documentation.
• Experience developing or reviewing rigorous methodologies, models, calculation packages, engineering standards, verification and validation practices, configuration control, peer review, and nuclear software quality processes.
• Strong written and verbal communication skills, including explaining complex analyses, assumptions, uncertainties, and conclusions to multidisciplinary teams.
• Must be mission-driven and willing to support extended hours when needed.

Nice to have

• Master’s degree or Ph.D. in nuclear engineering or a related technical discipline.
• Expertise in safety analysis, shielding, radiation dose and activation, instrumentation and controls, reactor operations, thermal-hydraulics, or radioactive-material transportation.
• Experience with high-temperature gas-cooled reactors, microreactors, advanced reactors, or first-of-a-kind nuclear systems.
• Experience with SCALE, Serpent, Shift, Griffin, MOOSE-based applications, or similar nuclear analysis tools.
• Proficiency with Python or another language for simulation automation, model generation, and analysis post-processing.
• Experience with coupled neutronics and thermal-hydraulics or other multiphysics analyses.
• Familiarity with DOE authorization processes, NRC licensing, nuclear industry codes and standards, or regulatory safety analysis.
• Experience supporting reactor testing, commissioning, startup, operational readiness, or mentoring engineers and providing technical review.

Culture & Benefits

• Full-time employment with substantial incentive stock options and comprehensive health benefits.
• Medical, vision, dental, life, accident, hospital, critical illness, commuter, FSA, and HSA benefits are available; parental leave includes eight weeks for all parents.
• Flexible PTO, a remote workday allocation, catered lunch, snacks, drinks, and company and team events.
• Eligible employees can access a fully covered Nuclear Engineering Certificate Program through Penn State University.
• In-person work environment at the El Segundo headquarters; the position involves technology subject to U.S. export controls, and offers are contingent on compliance.

Hiring process

• Applicants may contact hirify.global directly at recruiting@hirify.globalnuclear.com for immediate opportunities.
• Compensation and level are determined through evaluation of interview performance, experience, education, and qualifications.