← Back to all jobs

Molten Salt Engineer

CFS Energy · MA · Posted 2026-09-02

Apply on the company site →

Job description

About Commonwealth Fusion Systems: Commonwealth Fusion Systems is on a mission to deliver the urgent transition to fusion energy. Combining decades of research, top talent, and new technologies, we’re designing and building commercially viable fusion power plants. And we're working with policymakers, suppliers, and many others to build the energy industry of the future. We’re in the best position to make it happen. Since 2018, we’ve raised $4 billion of capital, making us the largest and leading fusion company in the world. Now we’re looking for more thinkers, doers, builders, and makers to join us. People who’ll bring new perspectives, solve tough problems, and thrive as part of a team. If that’s you and this role fits, we want to hear from you. Join the power movement as a Staff Multiphysics Modeler The Staff Multiphysics Modeler will work closely with the CFS tritium program and process engineering team to develop a fuel cycle model for the world's first fusion power plant, ARC, located in Chesterfield County, Virginia. The Staff Multiphysics Modeler will develop simulation toolkits and workflows that integrate first-principles multiphysics simulations with industrial process models to support technology development and subsystem integration for key fuel cycle systems, supported by the CFS fuel team to understand system requirements. The ideal candidate is an expert in heat and mass transport modeling, with an appreciation for simplicity and drive to build. This individual knows the power of optimizing devices by tuning material parameters, and appreciates a simple non-dimensional analysis and rigorous integrated simulations as the problem space requires. The candidate enjoys teaching and building tools that others can use independently. Applicants must have a degree in a relevant engineering or science discipline as well as experience in process modeling and programming. Applicants must have a demonstrated ability to apply a first principles approach in solving complex engineering problems and experience conducting cost-benefit to evaluate the economics of proposed solutions. Applicants must have demonstrated success working on engineering projects in multi-disciplinary teams generating effective solutions to complex problems. What you'll do: Perform corrosion testing of novel materials in molten salts Perform device testing in molten salts to obtain statistics on device performance Design and build new test cells for molten salt R D Assist with lab maintenance and upkeep Write and modify SOPs for safe handling of hazardous chemicals, including fluoride salts (FLiBe) What we're looking for: Bachelors degree in Chemistry, Chemical Engineering, Materials Engineering, Nuclear Engineering, Mechanical Engineering, or similar field 0-2 years of work experience Experience with R D work in a chemical or engineering laboratory Experience working with safety systems for hazardous chemicals Ability to learn new skills/subject matter quickly Ability to work effectively in a multidisciplinary team of engineers, scientists, technical staff and others Ability to clearly express and critique ideas Great communication and organizational skills Strong problem solving skills, ability to approach new problems with creativity Bonus points for: High temperature chemistry Molten salts Electrochemistry Ceramics Python, MATLAB, or equivalent for data analysis Building and commissioning new laboratory equipment CAD software Must-have requirements: Ability to occasionally lift up to 50 lbs Perform activities such as sitting, typing, standing, stooping, or climbing for extended periods of time Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, and cryogenics Willingness to travel or work required nights/weekends/on-call occasionally