Staff Multiphysics Modeler

Cfsenergy; Harvard (MA); On-site; USD 150,000 - 190,000; Full time

Job summary

Commonwealth Fusion Systems seeks a Staff Multiphysics Modeler to develop an integrated fuel cycle model for ARC, collaborating with the tritium program and process engineering teams. The role focuses on first-principles multiphysics simulations integrated with industrial process models to support technology development and subsystem integration for key fuel cycle systems.

The ideal candidate brings a strong background in heat and mass transport, comfort with rapid tool-building, and the ability

Qualifications

• Advanced degree with 10+ years of modeling chemical/process systems.
• Expert in heat and mass transport and transport phenomena.
• Proven experience building integrated process models and cross-functional collaboration.
• Experience with Python and/or Matlab.
• Experience with multiphysics tools such as COMSOL and process simulators like HYSYS.
• Willingness to travel and work nights/weekends/on-call as needed.

Responsibilities

• 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 R&D requirements for gaps in literature.
• Collaborate cross-functionally to ensure feasibility, economic viability, and state-of-the-art approaches.
• Develop processes and layouts for fueling subsystem blocks communicated through engineering docs.
• Generate detailed work plans and milestones aligned with R&D for validated models.
• Provide guidance to colleagues on modeling tools and outputs.
• Identify emerging trends and influence fuel cycle modeling strategy.

Skills

Multiphysics modeling

Cross-functional collaboration

Data analysis

First principles approach

Model validation

Education

Master’s degree or equivalent with 10+ years experience

Tools

Python

Matlab

COMSOL

HYSYS

Confluence/JIRA

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 and suppliers to build the energy industry of the future.

Since 2018, we’ve raised nearly $3 billion in capital, making us the largest and leading private fusion company in the world.

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 a 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.

Key Responsibilities

• 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 CFS’s fuel cycle modeling strategy

Qualifications

• 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 gases, 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
• 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
• 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.