Senior Mechanical Engineer — Molten Salt Process Systems

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

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