Reactor Physics Engineer I & II

Position Summary: Early to Mid-career technical professional supporting reactor physics and neutronics activities within a nuclear energy organization. Works with increasing independence under the direction of senior technical personnel and is expected to take ownership of defined technical tasks, calculations, analyses, documentation, and project-support activities. Applies reactor physics and neutronics principles to support engineering, design, safety, testing, and analytical programs while contributing technical problem-solving and disciplined technical execution. Functional Scope Reactor Physics - Apply core reactor-physics principles including neutron behavior, reactivity, flux distributions, power distributions, depletion, and feedback effects to support design activities, engineering evaluations, technical analyses, and project deliverables. Neutronics Analysis - Perform and support neutron-transport, deterministic, shielding-interface, depletion, and reactivity analyses as applicable to evaluate reactor behavior, reactivity control, power distributions, operating conditions, and design performance. Criticality Analysis - Support evaluation of fuel and material configurations, reactivity margins, moderation effects, and credible abnormal conditions where applicable. Computational Modeling - Develop, execute, maintain, and document analytical models using appropriate reactor-physics and neutronics tools; maintain traceability of assumptions, inputs, methods, and results. Core and Coupled-System Analysis - Support evaluations of core design, fuel-loading strategies, reactivity management, control systems, operating limits, and interactions with thermal-hydraulic, mechanical, materials, safety, and other engineering disciplines. Physics-Based Simulation - Perform physics-based calculations and simulations to predict reactor performance, investigate design alternatives, assess operating scenarios, support engineering decisions, and contribute to design development and technical-risk reduction. Validation & Verification - Support verification of model implementation and analytical methods and participate in validation activities using applicable benchmarks, experimental data, test results, or accepted references. Sensitivity and Uncertainty Analysis - Perform sensitivity and uncertainty evaluations to understand the impact of key assumptions, modeling approaches, nuclear data, operating parameters, and input variables on analytical results and technical conclusions. Safety and Licensing Support - Provide reactor-physics and neutronics inputs to safety evaluations, design-basis development, licensing analyses, regulatory responses, and supporting technical documentation under senior direction. Technical Documentation and Model Configuration - Prepare controlled calculations, technical reports, model records, assumptions logs, review packages, and supporting documentation consistent with company procedures, quality requirements, and configuration-management practices.

Key Responsibilities: Perform reactor-physics and neutronics calculations and computational analyses appropriate to experience level. Develop, execute, and maintain technical models under approved methodologies. Support criticality, neutron transport, reactivity, sensitivity, uncertainty, verification, and validation activities as assigned. Evaluate technical, measured, experimental, or test data and prepare controlled calculation packages. Collaborate with thermal-hydraulics, safety, systems, testing, and other engineering disciplines. Follow applicable engineering, quality, safety, configuration-management, and document-control requirements. Participate in technical reviews, team meetings, and continuous-improvement activities. Take increasing ownership of technical assignments and contribute to evolving technical programs.

Required Qualifications: Bachelor's degree in Nuclear Engineering, Engineering Physics, Physics, or related discipline. Approximately 3-10 years of relevant experience. Strong technical fundamentals and willingness to learn within a highly regulated, safety-critical environment. Ability to communicate clearly, document technical work, and collaborate across multidisciplinary teams. Demonstrated attention to detail, ownership, and problem-solving capability.

Preferred Qualifications: Experience supporting reactor physics, neutronics, criticality, core design, fuel-cycle, safety-analysis, advanced-reactor, research-reactor, or related nuclear-engineering programs. Experience within the nuclear industry, national-laboratory environment, or another highly regulated, safety-critical technical organization. Familiarity with recognized reactor-physics, neutron-transport, deterministic, criticality, depletion, shielding, or related analysis methods and computational tools. Experience developing, executing, documenting, or reviewing engineering calculations, analytical models, simulations, and technical evaluations. Experience supporting verification, validation, benchmarking, uncertainty analyses, test programs, or comparison of analytical results against experimental or operational data. Familiarity with applicable engineering standards, quality-assurance requirements, configuration-management practices, and technical-documentation processes. Experience working effectively within multidisciplinary or matrixed engineering organizations supporting multiple concurrent projects and stakeholders. Demonstrated ability to adapt quickly to evolving technical priorities and operate effectively in a growing organization.