Mechanical Engineering Internship - Summer

X-energy LLC conducts a thorough recruiting process and will never issue offers without interview to discuss qualifications and responsibilities. All applications will be submitted via our company career page,  We will never ask you to provide payment information as part of the recruiting process. If anyone claiming to represent X-energy directs you in a manner otherwise, please contact us at

This role is responsible for supporting professional employees working in an organizational function related to the Intern's area of study. Depending on the internship assignment, the intern may work alongside engineers, scientists, or industry professionals to contribute to various projects related to their area of study. Under guided supervision, interns will assist with various projects and tasks, contributing to the organization's goals while learning from experienced professionals in the field.

Please note:

This is a pipeline requisition for anticipated Summer 2027 internship openings. We accept and review applications on a rolling basis, and we extend offers as individual positions are finalized and specific team hiring needs are confirmed. Submitting an application places you in consideration for upcoming opportunities as they open.

• Support active engineering projects and analyses within your area of study, contributing to work that advances real reactor design and licensing efforts.
• Assist with the day-to-day technical and operational needs of your team.
• Conduct research, gather technical data, and synthesize findings to inform ongoing design and analysis initiatives.
• Help develop reports, technical documentation, and presentations that communicate results to internal stakeholders.
• Organize and maintain project files, technical records, and documentation to support traceability and quality.
• Participate actively in team meetings, design reviews, and brainstorming sessions - bringing ideas, asking questions, and offering perspective.

• Current enrollment in - or recent completion of - a degree in mechanical engineering or a closely related field from an accredited institution.
• Academic or hands-on knowledge in a minimum of one of the following areas:
  • Mechanical Design
    • Designing and developing mechanical or fluid systems, assemblies, or components.
    • One plus years of demonstrated hands-on experience developing and delivering hardware or manufacturing processes in a production environment is required. May include industry internship experience, hobby, or participation in collegiate engineering projects such as:
      Formula SAE, Baja SAE, Design Build Fly, Rocket Club, etc.
    • Hardware ownership including manufacturing and testing oversight.
    • Use of Computer-Aided Design (CAD) and product lifecycle management (PLM) software.
  • Thermodynamics
    • Use of 1D flow-solvers performing heat/energy and mass balance (e.g., RELAP, Flownex, NPSS, SINDA/FLUINT, Flomaster, or similar).
  • E.g. UG/NX, Solid Works, Pro-Engineer, Teamcenter, Windchill, or similar.
  • Structural Analysis
    • Analytical experience with structural analysis hand calculations and structural FEA software programs (e.g., ANSYS, ABAQUS, NASTRAN, FEMAP, CAESAR, ROHR, LS-DYNA, PIPESTRESS).
  • Thermal Hydraulics
    • Use of Computational Fluid Dynamics (CFD) analysis codes (e.g., STAR-CCM+, Fluent, or similar).
  • Mechanical Process Equipment
    • Piping, Ducting, HVAC, Fire Suppression, Pumps, Valves
• Proficiency with the Microsoft Office Suite (Outlook, Word, Excel, PowerPoint).
• Curiosity, initiative, and a collaborative mindset - you're eager to learn and ready to contribute.

Location: 9801 Washingtonian Blvd, Gaithersburg, MD

Work Site Expectations: Fully on-site, 5 days per week

Program Length: 10-week program (anticipated June-August…