Principal Mechanical Fluids Engineer

Hadron Energy, Inc. specializes in Micro Modular Reactor development and is seeking a Principal Mechanical Fluids Engineer to join their remote team. The role involves designing and analyzing fluid systems for their microreactors, ensuring compliance with nuclear industry standards while mentoring engineers and contributing to technical strategies.

Responsibilities:

• Own the design and analysis of assigned primary, secondary, and auxiliary fluid system scopes, including sizing of pumps, valves, heat exchangers, orifices, and piping networks
• Contribute to the technical strategy for fluid systems engineering, including selection of analysis methods, tools, and qualification approaches consistent with nuclear quality requirements
• Perform single-phase and two-phase flow analyses, hydraulic loss calculations, water-hammer / pressure transient evaluations, and net positive suction head (NPSH) studies
• Develop, execute, and review CFD analyses (STAR-CCM+, ANSYS Fluent / CFX, or OpenFOAM) for component-level flow distribution, mixing, thermal stratification, and heat transfer characterization
• Define thermal-hydraulic boundary conditions and interface loads for mechanical, structural, and safety analysis teams; reconcile system T-H results with component-level CFD
• Design and specify heat exchangers, steam generators, and other heat transfer equipment in coordination with vendors; perform sizing, rating, and performance verification per TEMA / HEI / ASME standards
• Evaluate flow-induced vibration (FIV), acoustic resonance, and erosion-corrosion risks per ASME OM, EPRI guidelines, and applicable industry standards
• Support pressure boundary and component design teams with hydraulic and thermal loads for ASME Section III stress and fatigue evaluations
• Develop and review P&IDs, flow diagrams, system descriptions, and operating procedures for fluid systems
• Perform peer reviews and contribute to QA documentation per ASME NQA-1 and Hadron's engineering procedures, operating effectively from a remote location with regular synchronous and asynchronous collaboration
• Mentor senior and mid-level engineers, and serve as a principal-level technical point of contact for fluid systems and thermal-hydraulic component engineering

Requirements:

• Bachelor's, Master's, or PhD in Mechanical Engineering, Nuclear Engineering, Chemical Engineering, or a closely related field
• Minimum 12 years of relevant experience in fluid systems engineering, thermal-hydraulic component design, or power plant fluid systems, with a track record of principal-level technical depth and independent ownership of complex design and analysis scopes
• Strong fundamental understanding of single-phase and two-phase fluid mechanics, convective heat transfer, boiling, and natural circulation
• Demonstrated experience designing and analyzing pumps, valves, heat exchangers, piping networks, and balance-of-plant fluid systems through detailed design, fabrication, and commissioning
• Hands-on proficiency with commercial CFD codes (STAR-CCM+, ANSYS Fluent / CFX, COMSOL, or OpenFOAM) and 1-D system codes (Flowmaster, AFT Fathom / Arrow, GOTHIC, or RELAP)
• Working knowledge of ASME B31.1 / B31.3, ASME Section III, ASME OM, TEMA, HEI, and applicable NRC SRP / RG guidance for fluid systems
• Experience working under stringent quality assurance programs such as ASME NQA-1, MIL-Q-9858A, or ISO-9000
• Experience evaluating water-hammer, flow-induced vibration, cavitation, and erosion-corrosion in safety-related fluid systems
• Registered Professional Engineer (Mechanical), or ability to obtain active license within 6 months
• Proficiency utilizing Mathcad and Python (or MATLAB) for engineering calculations, automation, and CFD post-processing
• Proven ability to work effectively in a remote-first environment: strong written communication, disciplined documentation habits, comfort participating in and running distributed reviews, and willingness to travel periodically to the SF Bay Area, vendor sites, and test facilities
• Exceptional technical writing and oral communication skills; ability to clearly translate analytical results into design decisions and to engage vendors and internal reviewers
• A high degree of integrity, a desire to foster teamwork, and a passion for solving the complex challenges of clean energy