Nuclear Engineer; Lead

Deploy the next generation of energy infrastructure

Applied Atomics delivers firm, clean electricity with proven technology. We design, build, and operate nuclear plants directly alongside the facilities they power. With no reactor science or new fuel to invent, we have no reason to stall. We are the first fully integrated nuclear power provider built to deploy now. Founded by a team of engineers and operators who built the launch sites, test complexes, and factories behind SpaceX, designed and commercialized nuclear reactors, and ran billion-dollar asset portfolios, the team is now focused on clean power deployment.

Applied Atomics is backed by Alpaca VC, Transition, and Morpheus Ventures.

Applied Atomics is seeking a Nuclear Engineer to own and drive the technical development of our reactor core, fuel, and associated nuclear systems. As one of our first nuclear engineering hires, you will define the nuclear architecture of our system, lead early-stage reactor and fuel design efforts, and act as the primary technical interface with our reactor-licensing partners. Your work will span reactor physics, core design, neutronics modeling, shielding, nuclear safety, fuel performance, and design adaptation of licensed reactor technology.

This role is ideal for someone who wants broad responsibility, thrives in a fast-paced hardware environment, and is excited to build and eventually lead a world-class nuclear engineering team.

We are transitioning nuclear energy from a theoretical science into a practical reality, and that requires practical problem-solvers. We need engineers who are eager to take direct responsibility for their work and see it through to completion. Your role will be critical in transforming complex designs into safe, reliable, and operational power plants that will operate for decades to come.

• Own reactor physics, neutronics, shielding, and nuclear design activities from concept through deployment.
• Develop and refine core design, reactivity coefficients, kinetics parameters, feedback mechanisms, and neutron energy spectra.
• Perform radiation transport, shielding, and criticality safety analyses.
• Conduct transient and accident-scenario evaluations to support design decisions and safety basis development.
• Perform dose consequence and source-term calculations (normal operations + beyond design basis events).

• Build and maintain reactor physics, shielding, and fuel performance models.
• Computer energy deposition distributions, power profiles, isotopic depletion, and fuel cycle analyses.
• Verify model assumptions and assess margin/conservatism across analyses.
• Lead Verification & Validation (V&V) efforts for nuclear analysis tools and workflows.

• Support fuel form selection, cladding and structural material evaluation, and fuel performance modeling.
• Contribute to reactor mechanical layout, shielding design, and core structural features.
• Work with thermal-hydraulic engineers to ensure robust coupling between neutronics and thermal-fluid analyses.

• Collaborate with licensed reactor technology providers to adapt designs for Applied Atomics’ requirements, constraints, and integration needs.
• Work with regulatory and licensing teams on technical inputs to safety basis, design certification, and licensing documentation.

• Server as the nuclear technical authority within a multidisciplinary, fast-paced engineering organization.
• Build out processes, methods, and eventually a team for nuclear analysis and reactor design.

• Take end-to-end responsibility for your projects, from initial concepts through to deployment and ongoing operations.
• Partner closely with our multidisciplinary team of experienced engineers to tackle complex, cross-functional challenges.
• Deliver high-quality work steadily and safely, ensuring every solution meets our rigorous quality standards while also for solving scalability issues in the future.
• Continually improve our internal engineering processes, documentation, and tools to support the team as we scale.

• Bachelor's degree in Nuclear Engineering or related field.
• 4+ years of nuclear engineering experience (or 2+ years w/ MS).
• Demonstrated experience with radiation transport and reactor physics modeling tools (OpenMC, MCNP, Serpent, SCALE, etc.).
• Experience with reactor design, core physics, criticality, and/or shielding.
• Basic understanding of thermal-hydraulics and coupled neutronics-thermal models.
• Familiarity with CAD tools (NX, Solid Works, Creo, etc.).
• Ability to operate across multiple cross-functional teams.
• Strong written and oral communication skills; able to explain complex topics simply.
• Self-starter, ownership mentality, and ability to drive tasks from concept to completion.

• Master's degree in Nuclear Engineering or related field.
• Experience with advanced…