Senior Mechanical Engineer

Humanity faces two critical challenges: securing reliable energy for everyone and aggressively lowering our environmental impact. Our client believes nuclear fission is the key to solving both at once. Today they are actively developing the technology to rapidly scale the deployment of nuclear fission. The Opportunity Their Founding Engineering team will design their first nuclear reactor. They will go from company founding to producing electricity with a critical reactor faster than any company in history. The Founding Mechanical Engineer is responsible for owning a large part of the nuclear power plant system from conceptual design through prototypes to project delivery. You will be empowered to make real-time decisions, solve complex problems on the fly, and own end-to-end processes. The role will require the readiness to develop subject matter expertise in nuclear engineering, as well as expertise in design for manufacturability, specifically related to heavy forgings, shell-and-tube heat exchangers, fluidic components, and more. If you are ready to be a hardware owner, eager to get out from behind a desk, and be hands‑on working alongside a world‑class production team, this may be the right role for you. Responsibilities Develop design concepts from a clean sheet and size reactor subsystems Collaborate with peers from different systems to develop designs that balance cost, efficiency, and deployment logistics Create detailed designs to implement concepts and generate CAD models in NX for components, assemblies, and reactor integration Build finite element models to assess your designs in detail and analyze your structures to prove they meet the needs of the reactor Apply first‑order hand calculations and empirical formulas to assess and iterate on your designs rapidly Validate your designs by building development articles to test manufacturability, heat transfer, and structural integrity Partner with build engineers and technicians to improve your designs Collaborate with peers to build the company’s first subscale reactor prototypes Support the assembly of your hardware in the factory, witness your designs being brought to life daily, and watch them power an abundant, clean future Basic Qualifications Bachelor's degree in mechanical engineering or a related technical discipline 3+ years of engineering experience designing, analyzing, or building mechanical hardware (internship and school projects experience qualify) Preferred Skills and Experience Strong ability to use data and analysis to make fast data‑driven decisions Strong understanding of engineering fundamentals Ability to perform trade studies and make clear recommendations using first principles and engineering fundamentals even with partial information Experience working at a nimble engineering organization or in a highly technical position that required a scrappy, entrepreneurial manner to accomplish tasks with tight time or budget constraints Experience building hardware or have a passion for contributing to a work product that operates in the real world Demonstrated rapid growth; you’ve held successive positions of increasing responsibility within an organization, were able to get yourself up to speed at a heroic pace, and accomplished something meaningfully difficult early in your career Experience leading or working on an engineering competition team, i.e. Formula SAE, Baja SAE, RoboSub, Combat Robotics or similar Additional Requirements Position will be based in the South Bay area of Los Angeles County and will require relocation if not already local. The position will be full‑time in the office. Ability to work extended hours and weekends as necessary Ability to travel to reactor construction sites in other states as necessary Compensation and Benefits Competitive Base Compensation - DOE Long‑term incentives, in the form of company stock or stock options, as well as potential discretionary bonuses and the ability to purchase additional stock at a discount through an Employee Stock Purchase Plan Access to comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, paid vacation, paid parental leave, and various other perks. About AdAstra AdAstra Talent Advisors is a headhunting and talent advising firm focused on the Climate, Space, and Defense sectors of Hard Tech. We specialize in pairing highly technical and executive talent with some of the world’s leading Hard Tech startups. At AdAstra, we catalyze the innovations that future generations depend on by placing the right people in the right seats. Our dedicated work enables inconceivable technology from Earth, to the stars. And it’s all because of trailblazing talent like you - those driven to do what’s never been done before. We care about long term relationships with both candidates and companies. Even if the role we initially discuss isn’t a perfect fit, it’s likely we’ll have something relevant to share with you in the future. Join us on our journey by following along via LinkedIn! #J-18808-Ljbffr