Nuclear Design Engineer Jobs in Colorado (NOW HIRING)

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!
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.

$190,000 - $220,000 a year
Candidates may be considered for other positions at Xcimer Energy, and our actual base salary will be determined on an individual basis and may vary based on job-related knowledge and skills, education, and experience. The range is published in accordance with Colorado Equal Pay for Equal Work Act and California Equal Pay Act.
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.
We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.