Principal Process Engineer, Fuel Cycle

About HelionWe are a fusion power company based in Everett, WA, with the mission to build the world's first fusion power plant, enabling a future with unlimited clean electricity. Our vision is a world with clean, reliable, and affordable energy for everyone.Since Helion's founding in 2013, we have raised $1.5 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors including Thrive Capital, LightSpeed Venture Capital, SoftBank, and others to propel us forward. Our current prototype, Polaris, has reached record-breaking plasma temperatures of 150 million degrees Celsius (13 keV). Helion is continuing to iterate and on the path to the world's first fusion power plant, Orion.This is a pivotal time to join Helion. You will tackle real-world challenges with a team that prizes urgency, rigor, ownership, and a commitment to delivering hard truths – values essential to achieving what no one has before. Together, we will change the future of energy, because the world can't wait.What You’ll Be Doing:You will be at the forefront of designing the world’s first continuous fusion fuel cycle – an opportunity to redefine the future of clean energy for the modern world. This role operates at the intersection of process design, system integration, and program strategy, owning the performance, scalability, and operability of the fuel cycle across its full lifecycle. You'll work collaboratively with Engineering, Science, R&D, Operations, and Leadership, serving as a technical authority focused on setting design direction, resolving first-of-a-kind engineering challenges, and delivering critical systems for an integrated, closed-loop fuel cycle. You will report to the Fuel Cycle Manager and work onsite at our Everett, WA office.You Will:Own delivery of major fuel cycle systems from concept through integration, including process design, procurement, installation, and commissioningDefine plant-level fuel cycle philosophy and tradeoffs, including operational approach, throughput, energy usage, holdup inventories, and safety across fuel cycle systemsUtilize first-principles analysis, modeling, and rigorous simulation tools to evaluate steady-state, dynamic, and fault scenarios to ensure design operabilitySet technical direction for and guide detailed design of process equipment (e.g., columns, reactors, membranes, heaters, exchangers, pumps, and piping) across ambient, high-temp, cryogenic, and vacuum conditionsDevelop and maintain core engineering design deliverables (PFDs, P&IDs, H&MBs, HAZOPs, and sizing calculations), ensuring technical rigor and consistency across the programDrive cross-functional alignment across Science, R&D, EHS, Fuel Cycle Operations, and Plant Engineering to deliver a cohesive and scalable fuel cycleLead high-level design reviews as the decision authority, resolving complex technical issues and ensuring alignment with program goalsEnsure technical rigor and alignment of detailed engineering work across team process designs (e.g., columns, reactors, membranes, cryogenic and vacuum systems)Mentor and develop senior engineers, establish engineering best practices, and shape team capability and technical standardsRepresent Helion as a technical authority in external engagements, communicating fuel cycle architecture, design decisions, and program direction through industry forums, conferences, and publicationsRequired Skills:Bachelor’s or Master’s degree in Chemical Engineering, Mechanical Engineering, Nuclear Engineering, or related field; advanced degree preferred12+ years of experience in chemical process design, translating process concepts into first-of-a-kind hardwareDeep technical expertise in transport phenomena (mass, heat, and momentum), thermodynamics, and reaction engineering applied to complex process systemsDecomposition of complex problems into fundamental physical principles, process objectives, and operational constraints to develop solutions grounded in first-principles reasoningDemonstrated ownership of large-scale integrated systems, defining requirements and driving clarity in ambiguous problem spacesDemonstrated accountability leading multi-disciplinary efforts and making system-level decisions with significant program impactAccountable as the technical authority for a technology domain, with expertise in relevant-to-fusion fuel cycle engineering, such as isotope separation, impurity separation, tritium handling, cryogenic systems, or vacuum systems#LI-Onsite #LI-TM1BenefitsOur total compensation package includes benefits, including but not limited to:Medical, Dental, and Vision plans for employees and their families 31 Days of PTO (21 vacation days and 10 sick days) 10 Paid holidays, plus company-wide winter break Up to 5% employer 401(k) match Short term disability, long term disability, and life insurance Paid parental leave and support (up to 16 weeks) Annual wellness stipendHelion is an equal opportunity employer and value diversity at our company. We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. If you need assistance or an accommodation during the interview process, please let us know.Compensation Range: $214K - $255KLocationEverett, WAEmployment TypeFull timeLocation TypeOn-siteDepartmentFuel CycleCompensation$214K – $255K