Principal Nuclear Materials Engineer

About Helion We 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 over $1 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors SoftBank and Lightspeed to propel us forward. Our last prototype, Trenta, completed 10,000 high-power pulses and reached plasma temperatures of 100 million degrees Celsius (9 keV). We are now operating Polaris, our next prototype on the path to the world's first fusion power plant. 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 Will Be Doing: You will play a key role in developing designs and materials suited for high-radiation environments, providing analysis and guidance to engineers on the behavior and performance of a wide range of materials under radiation exposure. In this onsite role, based at our Everett, WA office, you will report to the Director of Materials Science and collaborate closely with cross-functional teams to advance Helion’s mission. You Will: - Advise engineering design decisions based on radiation effects (due to neutrons) on materials used within the radiation shield vault, e.g., metals used in magnet coils, dielectrics used for structure, and ceramics - Partner with neutronics engineers to predict dpa, analyze, model, and predict macroscopic effects on material properties including thermal conductivity, electrical resistivity, and mechanical strength. Assess system-level radiation risk - Oversee testing campaigns to quantify impact of radiation on material properties - Lead strategic projects to expand capabilities - Perform literature reviews on radiation effects on materials of interest and distill the information into summaries for non-nuclear engineers - Operate in an environment with obstacles and changing requirements. Balance risks without compromising the delivery - Partner with other internal Helion teams, external vendors, national laboratories, and universities to gather the required capabilities. Develop your network and represent Helion at technical meetings and conferences Required Skills: - A professional understanding of radiation effects on materials, typically demonstrated by a degree in nuclear engineering, materials science, physics, or related discipline and 15+ years of hands-on work - 15+ years of experience handling radioactive material - 8+ years of experience working on non-aqueous corrosion and environmentally assisted degradation mechanisms (e.g., stress corrosion cracking, creep, accelerated fatigue) - 8+ years of experience working on neutron interactions leading to e.g., material transmutation or helium bubble generation - 8+ years of experience performing data analysis with a common coding language (Python, MATLAB, C++), data presentation, technical communication, and writing - Data presentation should include rigorous consideration of uncertainty and statistics #LI-TM1 #LI-Onsite Benefits Our 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 stipend Helion 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,