D. in Nuclear Engineering, Physics, or related fieldDeep experience with and understanding of MCNP, Serpent, or SCALEExperience with Multiphysics simulations and methods (thermal‑hydraulics, structural, heat transfer), reactor kinetics, safety analysis, or integrated systems modelingPreferred Skills & Experience:Advanced programming proficiency (Python, C++, or similar)Experience designing or developing high temperature gas reactors, heat pipe cooled reactors, microreactors, TRISO fuel, or other advanced reactorsStrong leadership and mentorship skillsDemonstrated success in regulatory processes (DOE, NRC, DoD)Previous experience at dynamic tech companies or startupsExperience with advanced reactor transient and systems analysis tools such as SAM, AGREE, PARCS, or equivalent nuclear systems codesExperience with reactor commissioning, startup testing, power ascension testing, and operational readiness activities for nuclear systemsDeep understanding of reactor shielding design, radiation transport analysis, and variance reduction methodologies, including experience with ADVANTG, MAVRIC, Attila4MC, or equivalent toolsExperience performing integrated nuclear‑thermal‑mechanical analyses for reactor structures and components, including structural graphite, high‑temperature steels, and other advanced reactor materialsDemonstrated ability to maintain design margins and performance requirements across coupled neutronic, thermal, mechanical, materials, and operational domainsStrong systems engineering mindset with the ability to work effectively across disciplinary interfaces and identify data needs for validation, verification, qualification, and licensing activitiesExperience planning and executing experimental programs to generate qualification data, including leveraging commissioning and power ascension campaigns to supplement analytical and modeling effortsUnderstanding of fuel and materials irradiation effects, in‑pile testing methodologies, and qualification approaches for advanced reactor systems and componentsExperience developing qualification strategies for reactor components, fuels, and materials through a combination of analysis, testing, irradiation campaigns, and operational data collectionCultureAt Antares, we like to specifically tie each role to our founding document's set of values–here are the top five cultural values we think you should believe at your core to be successful:Think in Systems - Energy and Defense are complex ecosystems with numerous stakeholders with competing priorities, conflicting policies, perverse incentives, and emergent and path‑dependent properties. Roles and Responsibilities:You will develop and provide expertise in a subset of the following:Lead complex neutronics modeling and Multiphysics analysisResponsible nuclear engineer for design and integration of components as assignedMentor junior engineersDevelop and implement modeling and simulation methods and toolsCoordinate validation and verification activitiesInterface directly with regulatory bodies for licensing and complianceSpearhead prototype testing and experimental campaignsLead cross‑disciplinary integration efforts across neutronics, thermal‑hydraulics, structural mechanics, materials, and reactor operations to ensure design margins are maintained across all Figures of Merit (FOMs) and safety‑critical performance metricsIdentify and define validation, verification, qualification, and testing requirements across engineering disciplines, including opportunities to leverage startup, commissioning, and power ascension testing data for model development and design maturationBasic Qualifications:Master's or Ph.