Senior Mechanical Engineer, Process Equipment

Cfsenergy; Harvard (MA); On-site; USD 150,000 - 210,000; Full time

Job summary

Commonwealth Fusion Systems is seeking a Senior Mechanical Engineer, Process Equipment, to advance molten salt systems and heat exchange equipment for ARC projects. You will design ASME-compliant vessels, piping, valves, and supporting components, interfacing with suppliers and internal teams to ensure safe, reliable operation.

The role emphasizes leadership in fluid system design, collaboration, and hands-on development from concept through commissioning, with a focus on safety and performance

Qualifications

• Bachelor's degree in Mechanical Engineering, Chemical Engineering, or equivalent.
• 8+ years of work experience.
• Experience with ASME BPVC, B31.3, and related equipment design.

Responsibilities

• Lead design of fluid process systems for molten salt equipment.
• Develop specifications for high-temperature process equipment (vessels, tanks, valves, pumps, piping).
• Interface with suppliers and construction teams for procurement, installation and commissioning.
• Support reliability of fixed equipment and piping stress evaluations.
• Collaborate with cross-functional teams and maintain safety-first mindset.

Skills

Problem solving

Communication

Team collaboration

Idea critique

Multidisciplinary work

Education

Bachelor's degree in Mechanical or Chemical Engineering

Tools

CAD software

P&IDs

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 Senior Mechanical Engineer, Process Equipment

The Fuel Cycle and Blanket Development Team is growing to deliver R&D and pilot-scale molten salt (FLiBe) systems to advance fusion. The technology readiness of FLiBe wetted components is modest due to the challenges of the high operating temperature, different corrosion modes, and the chemistry control required to achieve long term goals. The Fuel Cycle and Blanket Development team is looking for a Senior Mechanical Engineer to drive the design and delivery of molten saltprocess equipment including ASME tanks, heat exchangers, piping systems and gas processingequipment. This engineer will need to work collaboratively with internal teams at CFS as well as withkey external partners to reach ARC’s ambitious technical targets.

CFS engineering teams have a strong practice of carrying engineering risk where appropriate while attentively and aggressively managing safety risk, and we are looking for an engineer who will actively contribute to this culture.

• Lead and contribute to the design of fluid process systems for testing at varying scales


• Develop specifications and designs of high-temperature molten salt process equipment, including vessels, tanks, valves, pumps and piping systems


• Be the technical lead interfacing with suppliers and construction teams to procure, install and commission process equipment


• At later project stages, support fixed equipment mechanical reliability


• Support pipe stress evaluations working with piping stress engineers


• Collaborate across CFS teams to incorporate R&D learnings and interfacing system requirements into component designs and specifications


• Actively engage with suppliers, contactors and CFS teams to put safety first at all project stages


• Track projects and tasks against milestones and report progress up and across the organization

Requirements and Qualifications

• Bachelors degree in Chemical Engineering, Mechanical Engineering, or equivalent


• 8+ years of work experience


• Detailed knowledge of ASME BPVC and B31.3 and their use in designing process equipment and piping systems


• Design of industrial scale fixed equipment


• Design of higher temperature equipment and components


• Management of external partners and suppliers


• Design for hazardous fluid service


• Experience at a refinery, chemical plant, or heavy industrial facility preferred


• Familiarity with design/construction codes and standards such as ASME Section I, ASME Section VIII, ASME B31.3, API 510, API 570AND API 579 preferred


• Familiarity with P&IDs, CAD, process flow diagrams, analysis such as heat and mass balances


• Strong commitment to designing for and working in a safety-prioritized environment.


• 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


• Experience with corrosive fluid systems


• Experience with rotating equipment design, procurement, installation, commissioning and reliability.


• Experience with molten salt systems


• Experience with electro-chemical systems


• Analysis of pipe stress and support systems


• Analysis of vessel nozzle loads and stresses


• CAD software


• Ability to occasionally lift up to 50 lbs


• Perform activities such as typing, standing or sitting for extended periods of time


• Willing to occasionally travel to suppliers and support commissioning/test activities


• Dedication to safety to mitigate industrial hazards that may include heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics

#LI-Onsite

At CFS, we excel in fast-paced environments, driven by our values of integrity, execution, impact, and self-critique. As we grow, we’re eager to bring on mission-driven folks who offer diverse perspectives and fresh ways to tackle challenges.

We value diversity deeply and are proud to be an equal opportunity employer by choice. We consider all qualified applicants equally, regardless of race, color, national origin, ancestry, citizenship status, protected veteran status, religion, physical or mental disability, marital status, sex, sexual orientation, gender identity or expression, age, or any other basis protected by law.

This role requires compliance with U.S. laws concerning the export of controlled or protected technologies or information (collectively, “Export Control Laws”). Any offer of employment will be contingent on the need for compliance with such Export Control Laws.