SECTION I · THE BRIEF
Brief #80168Updated 16 JUL 2026DEVENS, MALeverKHOSLA VENTURES
Employbl Company Profile

Staff Multiphysics Modeler

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
1mo ago
Via
Lever
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Staff Multiphysics Modeler · Commonwealth Fusion Systems

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Job title
Staff Multiphysics Modeler
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 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:
  • Lead the development of an integrated power plant fuel cycle model
  • Develop models for unit operations and incorporate multi-effects in components
  • Develop simulation tools to enable targeted R&D for key fuel cycle technologies
  • Own the fuel cycle simulation tools and models
  • Validate models and identify key R&D requirements to enable validation where there are currently gaps in the literature
  • Collaborate cross-functionally with both internal and external experts to ensure fuel cycle models are feasible, economic and state-of-the-art
  • Develop processes and layouts for fueling subsystem blocks that are communicated through standard engineering documents
  • Generate detailed work plans and define milestones, integrated with R&D, to deliver validated models
  • Provide guidance to colleagues for use of developed modeling tools and outputs
  • Identify emerging trends and opportunities and influence CFSs’s fuel cycle modeling strategy
  • What we're looking for:
    • Master’s degree or similar experience with 10+ years in chemical engineering, mechanical engineering, physics, materials science, physical chemistry or similar
    • 10+ years experience modeling process systems
    • 10+ years experience in computer programming
    • Expertise with transport phenomena and chemical processes in gasses including demonstrated experience building integrated process models
    • Proven experience as an “expert” to evangelizing solutions and working across teams for shared solutions
    • Experience building and managing large data sets
    • Understanding of scalable simulations
    • Track record in version control
    • Data reduction and results analysis
    Bonus points for:
  • Experience with Python and/or Matlab
  • Experience with multiphysics tools such as Comsol
  • Exposure to process simulators like HYSYS
  • Use of engineering management tools
  • Confluence/JIRA and remote collaboration tools
  • Fusion energy experience
  • Chemical engineering
  • Atom and molecular mass transport
  • 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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    Where this role is based

    Devens, MA

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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