Senior Multiphysics Modeling Engineer for Fusion Power

Commonwealth-Fusion-Systems-5; Harvard (MA); On-site; USD 130,000 - 200,000; Full time

Benefits offered by this job

Competitive compensation with equity

13 Company-wide Holidays

Flexible vacation days

10 sick days

Generous parental leave policy

Health, dental, and vision insurance

401(k) with employer matching

Professional growth opportunities

Team-building activities

Job summary

Commonwealth Fusion Systems, a leader in fusion energy, seeks a Staff Multiphysics Modeler to advance the ARC fuel cycle program. You will build integrated, first‑principles multiphysics models connecting plant processes with industrial simulations to support technology development.

You’ll own modeling tools, guide cross‑functional teams, and drive milestones for validated models. Requires Master’s or equivalent in engineering/physics with 10+ years in modeling and programming.

Qualifications

• Master’s degree or 10+ years in engineering/physics/related fields.
• 10+ years modeling process systems experience.
• 10+ years experience in computer programming.
• Expertise with transport phenomena and chemical processes in gases.
• Proven experience evangelizing solutions across teams.
• Experience building and managing large data sets.
• Understanding of scalable simulations.
• Track record in version control.
• Data reduction and results analysis.

Responsibilities

• Lead the development of an integrated power plant fuel cycle model.
• Develop models for unit operations and multi‑effects in components.
• Create simulation tools to enable targeted R&D for fuel cycle tech.
• Own the fuel cycle simulation tools and models.
• Validate models and identify R&D requirements for literature gaps.
• Collaborate cross-functionally to ensure feasible, economical models.
• Develop fueling subsystem layouts communicated through engineering docs.
• Generate detailed work plans and milestones integrated with R&D.
• Provide guidance to colleagues on using modeling tools.
• Identify trends and influence fuel cycle modeling strategy.

Skills

Leadership

Cross-functional collaboration

Data analysis

Teaching

Education

Master’s degree or 10+ years experience in engineering/physics/chemistry

Tools

Python

Matlab

Comsol

HYSYS

Version control

Job description

Commonwealth Fusion Systems, a leader in fusion energy, seeks a Staff Multiphysics Modeler to advance the ARC fuel cycle program. You will build integrated, first‑principles multiphysics models connecting plant processes with industrial simulations to support technology development.

You’ll own modeling tools, guide cross‑functional teams, and drive milestones for validated models. Requires Master’s or equivalent in engineering/physics with 10+ years in modeling and programming.