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.