Staff Multiphysics Modeler

cfsenergy· Technology Development
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📍 Devens, MAFull time💰 USD 130K–200K

About this role

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
#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.

Frequently Asked Questions

What is the salary for the Staff Multiphysics Modeler role at cfsenergy?
The listed salary for this Staff Multiphysics Modeler position at cfsenergy is USD 130K–200K. This is an Full time role.
Where is the Staff Multiphysics Modeler position at cfsenergy located?
This Staff Multiphysics Modeler role at cfsenergy is based in Devens, MA. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Is the Staff Multiphysics Modeler role at cfsenergy full-time or part-time?
This is listed as a Full time position. It is posted as a Staff Multiphysics Modeler role in the Technology Development department at cfsenergy.
Which team or department does the Staff Multiphysics Modeler at cfsenergy belong to?
This Staff Multiphysics Modeler position is part of the Technology Development department at cfsenergy. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Staff Multiphysics Modeler position at cfsenergy?
Click the "Apply Now" button on this page. You will be redirected to cfsenergy's official application portal hosted on lever where you can submit your application directly.
When was the Staff Multiphysics Modeler job at cfsenergy posted?
This Staff Multiphysics Modeler position at cfsenergy was posted on Jul 16, 2026. Apply as soon as possible — early applications are often reviewed first.
Staff Multiphysics Modeler
cfsenergy · 💰 USD 130K–200K
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