Principal Nuclear Core Design Engineer

The Principal Nuclear Core Design Engineer supports the design, analysis, and licensing of the SMR‑300, an integral pressurized water reactor small modular reactor. This role plays a critical part in core physics analysis, fuel management evaluations, and preparation of nuclear licensing documentation in support of ongoing SMR‑300 development. The Principal Nuclear Core Design Engineer will join an established and growing core design and nuclear analysis team and is expected to independently execute complex technical analyses, benchmark methods and models, clearly document results, and mentor junior engineers in analysis techniques and technical documentation. The ideal candidate brings deep reactor physics expertise, strong analytical and technical writing skills, and experience supporting NRC licensing activities.

Location: Flexible — role may be based in Camden, NJ; Jupiter, FL; Cranberry, PA; Madrid, Spain; Bristol, UK; or Kyiv, Ukraine

Primary Responsibilities:

• Perform reactor core design and reload analyses supporting steady‑state operation, transient evaluations, and safety analyses
• Develop, validate, and maintain core physics models, including lattice and nodal calculations
• Generate physics parameters and cross‑section data for use in safety and system analyses
• Conduct benchmarking and code qualification activities against experimental data and industry standards
• Support fuel cycle optimization, reactivity control strategies, and long‑term core performance evaluations
• Prepare detailed technical analyses and reports for internal use and external regulatory submittals
• Contribute to licensing documentation, including PSAR, FSAR, and responses to NRC Requests for Additional Information (RAIs)
• Participate in technical discussions with cross‑functional internal teams, external partners, clients, and the U.S. Nuclear Regulatory Commission
• Mentor and provide technical guidance to junior engineers on analysis methodologies and documentation standards
• Support continuous improvement of core design tools, processes, and technical documentation practices

Requirements:

• Eligibility to work under U.S. Department of Energy 10 CFR Part 810 export control regulations
• Bachelor’s degree in Nuclear Engineering, Physics, or a closely related field with 10+ years of relevant experience
  • OR Master’s degree with 8+ years of relevant experience
  • OR PhD with 6+ years of relevant experience
• Demonstrated experience in reactor core physics, fuel management, and neutronic analysis
• Proficiency with industry standard core analysis tools such as CASMO/SIMULATE
• Familiarity with NRC licensing processes, including NUREG 0800 Chapter 4 and Chapter 15 requirements
• Strong technical writing, documentation, and communication skills
• Ability to work independently while contributing effectively within multidisciplinary teams
• Proficiency with industry‑standard analysis tools such as SCALE, MCNP, or equivalent codes
• Experience with reactor pressure vessel fluence evaluations and understanding of radiation damage mechanisms
• Programming or scripting experience (e.g., Python) to support analysis automation and data processing

A Generation Ahead by Design™
Investing in people who power the future.

We believe great work deserves great rewards. Our benefits go beyond the basics, reflecting our commitment to supporting your whole self…your health, your future, and your career growth. This includes:

Compensation:

• Annual compensation based on skills and experience ranging from $160,000 to $190,000

Benefits:

• Medical, dental, and vision insurance
• 401(k) retirement plan with company match
• Paid time off and 11 Paid Holidays
• Company-paid life and AD&D insurance
• Employee Assistance Program
• Wellness resources and voluntary benefits
• Training and educational assistance 

If you’re driven to solve meaningful challenges and make a lasting impact, we invite you to build your career at Holtec—a generation ahead by design™.