Senior Nuclear Engineer

About the role

You will own the end-to-end engineering responsibility for a critical reactor component or analysis domain, ensuring that design choices are technically sound and compliant. You will operate as a trusted nuclear authority, translating high-level mission requirements into detailed engineering specifications and leading the technical execution of complex projects. In a fast-moving environment, you will make timely, data-driven decisions that balance safety, performance, and schedule. You will mentor junior engineers and elevate the entire team through clear technical communication and hands-on problem solving. Your work will directly influence the deployment of advanced nuclear systems for terrestrial, maritime, and space applications.

Key facts

What you'll do

• Lead complex neutronics modeling and multiphysics analysis for reactor components and system configurations.
• Serve as the responsible nuclear engineer for the design, integration, and qualification of assigned reactor subsystems and components.
• Mentor junior engineers, fostering a high-performance team environment that accelerates technical growth and delivery.
• Develop and implement advanced modeling and simulation methods, tools, and workflows to support design exploration and decision-making.
• Coordinate validation and verification activities across disciplines to ensure fidelity, traceability, and compliance.
• Interface directly with regulatory bodies such as the NRC, DOE, and DoD to advance licensing, safety analysis, and compliance objectives.
• Spearhead prototype testing and experimental campaigns, integrating results into design maturation and verification.
• Lead cross-disciplinary integration efforts among neutronics, thermal-hydraulics, structural mechanics, materials, and reactor operations to maintain design margins across all Figures of Merit and safety-critical performance metrics.
• Identify and define validation, verification, qualification, and testing requirements, and leverage startup, commissioning, and power ascension testing data to refine models and designs.
• Drive the development and execution of qualification strategies for reactor components, fuels, and materials through analysis, testing, irradiation campaigns, and operational data collection.
• Apply deep expertise in reactor shielding design, radiation transport analysis, and variance reduction methodologies using tools such as ADVANTG, MAVRIC, or Attila4MC.
• Perform integrated nuclear-thermal-mechanical analyses for reactor structures and components, including materials such as graphite, high-temperature steels, and advanced reactor alloys.
• Ensure that design margins and performance requirements are maintained across coupled neutronic, thermal, mechanical, materials, and operational domains throughout the system lifecycle.
• Demonstrate strong systems engineering capabilities, working effectively across disciplinary boundaries to identify data needs, close verification gaps, and support licensing and regulatory acceptance.
• Plan and execute experimental programs to generate qualification data, aligning testing with modeling efforts and leveraging commissioning and power ascension campaigns to mature design confidence.

Requirements

• Hold a Master's or Ph.D. in Nuclear Engineering, Physics, or a closely related technical field.
• Demonstrate deep experience with and understanding of reactor physics and radiation transport codes such as MCNP, Serpent, or SCALE.
• Possess extensive background in multiphysics simulations, including thermal-hydraulics, structural mechanics, heat transfer, reactor kinetics, safety analysis, and integrated systems modeling.
• Show proven ability to work effectively in team-oriented environments, collaborating with cross-functional peers to mature nuclear concepts and deliver complex engineering outcomes.
• Maintain a strong commitment to safety, quality, and regulatory compliance, with a track record of operating in highly regulated nuclear environments.
• Exhibit ownership of challenging technical problems, persistence in troubleshooting complex systems, and the ability to communicate rigorous analysis to diverse stakeholders.
• Be comfortable operating in a fast-paced, evolving organization while maintaining rigorous technical discipline and documentation.

Nice to have

• Advanced programming proficiency in Python, C++, or similar languages.
• Experience designing or developing high-temperature gas reactors, heat pipe cooled reactors, microreactors, TRISO fuel, or other advanced reactor technologies.
• Demonstrated success in navigating regulatory processes with the DOE, NRC, or DoD.
• Previous experience at dynamic technology companies or startups in energy, aerospace, or defense sectors.
• Familiarity with advanced reactor transient and systems analysis tools such as SAM, AGREE, PARCS, or equivalent nuclear systems codes.
• Hands-on experience with reactor commissioning, startup testing, power ascension testing, and operational readiness activities for nuclear systems.
• Deep understanding of reactor shielding design, radiation transport analysis, and variance reduction methodologies using tools like ADVANTG, MAVRIC, or Attila4MC.
• Experience performing integrated nuclear-thermal-mechanical analyses for reactor structures and components, including graphite, high-temperature steels, and other advanced materials.
• Strong systems engineering mindset with the ability to work effectively across disciplinary interfaces and identify data needs for validation, verification, qualification, and licensing.
• Experience planning and executing experimental programs to generate qualification data, including leveraging commissioning and power ascension campaigns to supplement analytical and modeling efforts.
• Understanding of fuel and materials irradiation effects, in-pile testing methodologies, and qualification approaches for advanced reactor systems and components.
• Experience developing qualification strategies for reactor components, fuels, and materials through a combination of analysis, testing, irradiation campaigns, and operational data collection.

Practical notes

• Full-time based in Los Angeles.
• Willingness to travel as required for testing, commissioning, regulatory meetings, and customer engagements.
• Availability for interviews only during the stated timeframe, if provided.
• Employment eligibility to work in the United States required.