SECTION I · THE BRIEF
Brief #02720Updated 02 SEP 2026DEVENS, MALeverKHOSLA VENTURES
Employbl Company Profile

Molten Salt Engineer

Commonwealth Fusion Systems (CFS) is an American company founded in 2018 aiming to build a compact nuclear fusion power plant based on the ARC tokamak reactor concept. The company is based in Cambridge, Massachusetts,…

Location
Devens, MA
Company size
500–2,000
Posted
Today
Via
Lever
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Molten Salt Engineer · Commonwealth Fusion Systems

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Job title
Molten Salt Engineer
Job location
Devens, MA
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 Molten Salt Engineer

Salt chemistry is a critical driver of corrosion, hydrogen speciation, and material behavior under irradiation. As the Blanket System team scales up to larger systems, maintaining precise control over salt chemistry is vital. We are seeking an entry-level Molten Salt Engineer to support our experimental testing operations. Initially, you will focus on executing standard operating procedures (SOPs), conducting routine materials testing, and maintaining rigorous quality controls. As you build familiarity with our systems, your role will expand to include experimental design, test cell design and construction, and leading projects in materials corrosion and blanket health monitoring. Ideal candidates will have a background in chemistry, chemical engineering, or a related discipline.

The Blanket System team has a strong culture of teamwork, supportive safety culture, and pragmatic risk management. We are looking for an engineer who will fit and actively contribute to this culture.

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
  • View job listing ↗
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    Commonwealth Fusion Systems headquarters

    Cambridge, MA

    Company size

    5002,000 employees

    Founded

    2018

    Total raised

    $3,877,000,000

    View company profile ↗

    Funding rounds