Director of Nuclear Engineering

Number of employees

200

Denver, CO

Posted on: 2026-05-28

Category: energy

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Employment type:

Full time

Experience required:

Director

Salary

Salary not provided

About the company:

Xcimer Energy is a fusion energy company focused on commercializing laser-driven inertial confinement fusion, which it describes as the only scientifically validated form of fusion energy. The company is developing high-energy excimer laser systems designed to ignite fusion reactions using fuel derived from seawater and lithium, with the goal of delivering safe, clean, and affordable electricity that is cost-competitive with fossil fuels and renewables. Its mission centers on decarbonizing energy-intensive sectors such as artificial intelligence infrastructure, desalination, and industrial processes that require firm, always-on, carbon-free power. Xcimer's technical approach relies on electron-beam-pumped excimer lasers combined with a pulse compression technique called Stimulated Brillouin Scattering (SBS), which compresses microsecond laser pulses to nanosecond durations without damaging optics. In 2024 the company broke ground on Phoenix, its first prototype high-energy laser system, located in Denver, Colorado, and announced the start of its operations in June 2026. Phoenix is the first electron-beam-pumped excimer laser built in the private sector in more than two decades and validates key elements of the company's low-cost laser fusion architecture. Xcimer's longer-term target is Athena, which it describes as the world's first laser fusion power plant, expected to deliver 400 megawatts of continuous clean energy by 2035. The company has received a U.S. Department of Energy approval of its fusion power plant preconceptual design and technology roadmap milestone, and collaborates with industrial partners such as TRUMPF Laser SE. With a team of nearly 200 engineers, physicists, and business professionals, Xcimer positions itself as the most technically mature private laser fusion company.

Xcimer Energy leverages decades of research on Inertial Fusion Energy (IFE) combined with groundbreaking new laser architecture. Our mission is to deploy fusion power plants to meet global decarbonization goals as fast as possible. Xcimer has assembled a team of leaders in tough tech, fusion science, and manufacturing with a track record of rapid execution. Supported by leading investors, Xcimer is uniquely positioned to deliver limitless, clean, fusion power to combat climate change. Join us in powering a better world with inertial fusion!
 
This is a full-time, onsite role based at our headquarters in Denver, CO.
 
As the Director of Nuclear Engineering, you will lead and grow Xcimer’s Nuclear Engineering discipline, ensuring the company applies rigorous nuclear engineering practices across all programs, facilities, and lifecycle phases. You will serve as a technical authority within Xcimer’s matrix engineering organization, partnering closely with Program leadership and peer Department Heads to establish standards, mentor engineers, and ensure high-quality technical execution. We are looking for a technical leader to apply their expertise in nuclear engineering, systems thinking, and organizational leadership to positively impact the future of energy!

Equal Employment Opportunity
Xcimer Energy is proud to be an Equal Opportunity/Affirmative Action Employer and is committed to attracting, retaining, and developing a highly qualified, diverse, and dedicated work force. Xcimer Energy hires and promotes people on the basis of their qualifications, performance, and abilities. We support the establishment and maintenance of a workplace that fosters trust, equality, and teamwork, in which all employees recognize and appreciate the diversity of individual team members. We provide all qualified applicants for employment and employees with equal opportunities for hire, promotion, and other terms and conditions of employment, regardless of their race, color, religion, gender, sexual orientation, gender identity, national origin/ethnicity, age, physical or mental disability, genetic factors, military/veteran status, or any other status or characteristic protected by federal, state, and/or local law. Xcimer Energy will consider for employment qualified applicants with criminal histories in a manner consistent with applicable federal, state, and local laws. For more information on “EEO Is the Law,” please see here and here.
 
Benefits
Xcimer offers a comprehensive benefits package designed to support employee health, well-being, and long-term success. Benefits include medical, dental, and vision coverage; basic and supplemental life insurance; short- and long-term disability; paid parental leave for employees at the time of birth or adoption; and a 401(k) with a company match of up to 6%. Eligible employees also receive equity, allowing them to share in the company’s long-term success.
Xcimer operates under a flexible Paid Time Off (ATO) approach. Rather than a fixed number of vacation days, employees are trusted to take the time they need to rest and recharge while meeting the expectations of their role and team. In addition, employees receive paid sick time, 13 company-paid holidays, and an annual paid company shutdown. Benefits are available to regular employees, including part-time and fixed-term roles, as well as interns, with eligibility varying by benefit.

Responsibilities

  • Build, lead, and grow the Nuclear Engineering Department, including hiring, onboarding, mentoring, and performance development of engineering staff.
  • Develop career paths and technical leadership pipelines for nuclear engineers while fostering a culture of technical rigor, collaboration, safety, and continuous improvement.
  • Establish, document, and maintain nuclear engineering standards, methods, and best practices across concept development, design, testing, and operations.
  • Define and maintain the nuclear design basis for Xcimer facilities and programs, ensuring assumptions, analyses, and requirements support performance, safety, and regulatory objectives.
  • Partner with Program Directors and Managers to ensure nuclear engineering activities are appropriately scoped, resourced, prioritized, and scheduled.
  • Identify nuclear engineering risks early and collaborate cross-functionally to develop and implement mitigation strategies.
  • Ensure disciplined execution of core nuclear engineering activities, including radiation transport and shielding analysis, activation analysis, source term definition, uncertainty analysis, and support for radiological safety and hazards analysis.
  • Collaborate closely with Systems Engineering, Facilities, Test, Operations, ES&H, and peer engineering departments to integrate nuclear engineering considerations into system architectures, facility designs, and operational procedures.
  • Define and execute a long-term roadmap for nuclear engineering capability growth, including external partnerships with national laboratories, academic institutions, and industry collaborators.
  • Represent Xcimer in technical forums and within the broader nuclear engineering community to build technical credibility and attract top-tier talent.
  • Qualifications

    • Education: Advanced degree in Nuclear Engineering or closely related technical field; PhD strongly preferred.
    • Experience: 15+ years of experience in nuclear engineering, including senior technical leadership responsibilities.
    • Demonstrated experience building, mentoring, and leading high-performing technical teams.
    • Strong foundation in radiation physics, nuclear engineering fundamentals, and analytical methods.
    • Experience with deterministic and Monte Carlo neutron/photon transport methods.
    • Experience using nuclear engineering analysis tools such as MCNP, OpenMC, or equivalent software.
    • Experience planning and managing technical work, including schedules, budgets, and performance metrics.
    • Experience operating effectively within matrix organizations and multidisciplinary technical environments.
    • Excellent written and verbal communication skills with the ability to communicate complex technical concepts to both technical and non-technical audiences.
    • Must be a U.S. citizen or national, U.S. permanent resident (current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum.
    •  

    Desired

  • Experience within fusion energy, high-radiation facilities, or other advanced energy systems.
  • Experience collaborating with national laboratories, universities, or large multi-institution technical programs.
  • Experience establishing engineering standards and improving technical rigor across organizations.
  • Publication record or recognized technical leadership within the nuclear engineering community.
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