What are the responsibilities and job description for the Intern - Nuclear Engineer - Summer 2026 position at Commonwealth Fusion Systems?
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 working with policymakers and suppliers to build the energy industry of the future.
We’re in the best position to make it happen. Since 2018, we’ve raised nearly $3 billion in capital, making us the largest and leading private 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 Nuclear Engineering Intern
We are looking for talented technical interns to join our team! CFS interns are highly valued within the organization and placed into meaningful and challenging roles.
\n- 12-16 week internship program
- 40-50 hours per week with set hourly salary based on year in school
- Opportunity available at our Devens, MA location. If an intern is going to be on site, you will be responsible for your own transportation and housing
- Specific project assignments and required technical skillset will vary based on the team’s existing need.
- Opportunities available for currently enrolled college students in all levels of schooling from bachelor’s degree to PhD
- Interns must be authorized to work in the United States for any employer
- Work on projects such as, but not be limited to: Neutronics analyses such as energy deposition in delicate materials or shielding sensitivity studies for diagnostic design
- Collaborate with engineers on the Nuclear Engineering team to do neutronics calculations (heating, activation, flux, dose, etc) to support the design and operation of SPARC, the scoping of ARC, and any other nuclear engineering needed
- Student in nuclear engineering, undergrad or Master's
- Neutron Transport or Neutronics or a Reactor Theory course completed by the start of the internship
- Experienced in MCNP or OpenMC
- Experienced in CAD and/or Python (optional)
- Strong communication skills and a willingness to learn
- Must work well in a team
- Must be highly self-motivated and driven to execute quickly with excellent troubleshooting/problem-solving skills
- Willingness to travel or work required nights/weekends/on-call occasionally
- Perform activities such as typing, standing, or sitting 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
#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.
Salary : $23 - $35
