Job Details

Stealth Communications seeks to fill multiple positions for the role of: SMR Core Physics & Neutronics Engineer to lead the advanced modeling, simulation, and optimization of our Small Modular Reactor (SMR) cores.

This role is pivotal in driving reactor physics innovation, ensuring core design efficiency, safety, and regulatory compliance. You should have deep expertise in neutron transport, fuel cycle analysis, reactivity control,, and advanced computational methods for reactor physics simulations.

This position is based onsite in Honolulu, HI, with occasional travel as required. Security clearance is required.

Responsibilities

• Develop, validate and optimize neutron transport models for steady-state and transient core behavior, ensuring compliance with safety, regulatory, and performance requirements.
• Perform high-fidelity neutronics modeling using Monte Carlo, deterministic, and hybrid methods with tools such as MCNP, SCALE, SERPENT, CASMO, MPACT, OpenMC and ATTILA.
• Conduct full-core depletion calculations for fuel cycle optimization, burnup credit analysis and isotopic inventory tracking.
• Perform reactivity feedback analysis, including Doppler broadening, moderator temperature coefficient, fuel temperature coefficient, and xenon/samarium poisoning effects.
• Lead core design parameter studies, optimizing core configurations, power distribution and neutron flux shaping for longer fuel cycles and enhanced power peaking management.
• Develop high-fidelity multi-physics coupling between neutronics and thermal-hydraulics codes (e.g., RELAP5, TRACE, CTF, or Subchannel codes) for integrated safety and performance assessments.
• Conduct control rod worth calculations, shutdown margin evaluations and transient reactivity insertion event modeling.
• Support nuclear safety case development, including subcriticality analysis, probabilistic risk assessment and shielding effectiveness verification.
• Perform gamma and neutron transport analysis for radiation shielding optimization, activation product predictions, and radiation damage assessment.
• Lead the development of next-generation core physics simulation frameworks, integrating AI/ML-based predictive modeling and uncertainty quantification methods.
• Develop neutronics benchmarks and validate computational models against experimental reactor data, including from critical assemblies and test reactors.
• Collaborate with regulatory specialists, technical submittals, and compliance with DOE and international nuclear safety standards.
• Contribute to research on advanced fuel cycles, including HALEU, TRISO fuel, molten salt reactors (MSRs), fast reactors and hybrid nuclear-renewable integration.
• Provide technical leadership in computational neutronics, guiding cross-functional teams in core performance assessments, fuel management strategies and reactor design trade-off studies.
• Prepare technical reports, regulatory justification and R&D whitepapers for internal stakeholders, and partners.

Qualifications

• Must possess an active, transferable TS/SCI CI Poly U.S. government-issued security clearance before starting.
• Ph.D. (preferred) or Master's degree in Nuclear Engineering, Physics or closely related field with a strong emphasis on reactor physics and neutronics.
• 13+ years of experience in nuclear reactor core physics, computational neutronics and high-fidelity modeling.
• Expertise in Monte Carlo and deterministic neutron transport theory including multi-group and continuous-energy transport methods.
• Strong background in full-core modeling, reactor kinetics and time-dependent neutron flux evolution.
• Proficiency with neutron transport, cross-section generation, and resonance self-shielding calculations.
• Experience with fuel burnup modeling, actinide transmutation pathway and fission product yield calculations.
• Deep understanding of neutron moderation, reflector design and neutron leakage minimization for SMR core efficiency.
• Experience integrating neutronics, thermal-hydraulic and structural mechanics simulations for multi-physics analysis.
• Experience working with DOD, DOE, NRC and knowledge of international nuclear regulatory frameworks(including 10 CFR Part 50, Part 52, and Part 810 regulations)
• Knowledge of ANSI/ANS neutronics and reactor physics standards as well as IAEA guidelines for SMR deployment.
• Experience performing criticality safety evaluations and subcritical margin assessments for nuclear fuel handling and storage.
• Strong proficiency in HPC-based reactor physics simulations, including parallel computing techniques and GPU-accelerated Monte Carlo methods.
• Experience developing custom neutronics solvers or modifying open-source neutron transport codes.
• Programming experience in ASM, C++ and Python for workflow automation, data post-processing and numerical methods development.
• Experience with Generation IV reactor designs, including fast neutron reactors, liquid-metal-cooled reactors and high-temperature gas reactors (HTGRs).
• Knowledge of fusion-fission hybrid reactor concepts and advanced breeder reactor cycles.
• Strong record of peer-reviewed research publications, conference presentations, or contributions to reactor physics code development.
• Excellent technical communication skills, with experience presenting complex data to government agencies, national labs, and internal stakeholders.
• Capable of independent work and collaboration within a diverse and multidisciplinary team, including scientists, engineers, business professionals, and military/ex-military personnel.

Starting Salary: $425,000 with sign-on bonus of $500,000 + relocation expenses