Deploy the next generation of energy infrastructure with Applied Atomics 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. About the role: Applied Atomics is seeking a Sr. Mechanical Engineer to lead the design, development, and build-out of the balance-of-plant systems for our first-of-a-kind (FOAK) nuclear power plant. This includes major Rankin cycle systems such as the main steam system, condensate system, feedwater system, air-cooled condenser (ACC), heat exchangers, and related thermal-mechanical equipment. This is a highly impactful, senior engineering role. You will own major fluid and thermal systems end-to-end; from concept development and analysis to detailed design, vendor engagement, procurement, integration, testing, and commissioning. This position is perfect for an engineer with deep experience designing industrial fluid systems, large-scale mechanical systems, or power-plant hardware; including those from aerospace (launch & test infrastructure), energy, oil & gas, chemical plants, turbomachinery, or thermal power backgrounds. Why we need you 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. What you will do Key Responsibilities • Ownership of major balance-of-plant (BOP) systems, including but not limited to: main steam system & piping, feedwater system, condensate system, air-cooled condenser systems, heat exchangers and auxiliary systems, turbine-side thermal cycle equipment & interfaces. • Lead trade studies, concept development, and system architecture decisions to meet performance, reliability, safety, and cost targets. • Develop mechanical and physical system design concepts for BOP structures, systems, and components (SSCs). • Ensure designs comply with applicable design criteria, requirements, and system interfaces. • Perform and/or review thermal, structural, and fluid analyses, using both hand calcs and FEA/CFD tools when required. • Conduct detailed studies on (but not limited to): steam generator (turbine coupling), condenser performance, heat exchanger optimization, cycle efficiency, transient response and system dynamics. • Develop and validate system simulations and analytical models. • Apply engineering requirements derived from design basis documents, system interfaces, hazards, and safety analyses. • Interpret and implement industry codes and standards (ASME, API, NRC, etc.). • Participate in plant-level safety analyses, reliability evaluations, and performance assessments. • Manage system development and implementation through all life cycle phases. • Solve complex technical problems and deliver high quality engineering work products on time and within budget. • Collaborate with interfacing system owners. • Ensure proper thermal coupling and seamless integration across BOP, NSSS, and reactor systems. • Source equipment suppliers, evaluate vendor capabilities, and support procurement efforts. • Provide input to equipment specifications. • Prepare, lead, and support system design reviews based (PDRs, CDRs, etc.). • Develop design documentation, including (but not limited to) design basis documents, technical reports, calculations, design descriptions, and drawings. • Support documentation for regulatory submissions (e.g., NRC). • Create, review, and validate system simulations and analyses. • Define and manage Bills of Materials (BOMs), component specifications, and configuration control. • Develop manufacturing processes, assembly sequences, assembly & integration plans, and testing procedures. • Support build, commissioning, and plant bring-up activities. • Create and maintain CAD. • Develop system schedules, budgets, and resource plans with company leadership. • Manage external engineering contractors or design partners as needed. Additional Responsibilities • 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 What you bring to the table Need to haves: • Bachelor’s degree in Mechanical Engineering or related field. • 10+ years of mechanical or fluid system design experience (7+ years w/ MS). • Strong proficiency in fluid/thermal-mechanical design and analysis, including hand calcs and FEA (ANSYS, Abaqus, FEMAP, etc.). • Proficiency with CAD tools (NX, SolidWorks, Creo, etc.). • Solid understanding GD&T and tolerance stack-ups. • Experience with piping, pressure vessels, steam cycle equipment, high-temperature systems, and/or industrial fluid systems. • Experience with mechanical process equipment design, installation, or operation. • Demonstrated experience across the full produce / system lifecycle. • Familiarity with applicable mechanical/industrial codes and standards (ASME, API, NRC, NFPA, etc.). • Ability to operate across multiple cross-functional teams. • Strong technical communication and documentation skills. • Self-starter, ownership mentality, and ability to drive tasks from concept to completion. Nice-to-haves: • Master’s degree in Mechanical Engineering or related field. • Experience with steam turbine and Rankine cycle system development. • Experience in nuclear power, fossil power, oil & gas, aerospace ground systems, or large industrial plant design. • Prior FOAK (first-of-a-kind), reactor development, or first-of-a-kind industrial project experience. BENEFITS & PERKS FOR ELIGIBLE EMPLOYEES • Substantial incentive stock plan for all full-time employees. • Medical / Vision / Dental (details forthcoming). • Flexible PTO policy. • Hybrid and remote work options depending on role. • Other benefits to be announced at offer stage. We are an equal opportunity employer, and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity or expression, pregnancy, age, national origin, disability status, genetic information, protected veteran status, or any other characteristic protected by law. We are unable to provide visa sponsorship at this time. This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicant’s capacity to serve in compliance with U.S. export controls. Remote pay range $150,000-$250,000 USD