Senior Plant Thermal Hydraulic Methods Engineer

Our client is seeking a Senior Engineer, Plant Thermal Hydraulics Methods – Contractor as part of a growing team supporting the design and licensing of the Natrium Demonstration reactor and is primarily responsible for developing methods to perform Licensing Basis Events (LBE) analyses.

The Senior Engineer may also contribute subject matter expertise to other projects under development by the client's Sodium Fast Reactor (SFR) Program. Other engineering activities include, but are not limited to, system transient codes development and maintenance, performing reactor transient analyses, code benchmark with Integral Effect Tests (IETs) or Separate Effect Tests (SETs), scaling analysis, software commercial-grade dedication, contributing to code assessment and adequacy evaluation, as well as performing verification and validation activities.

Tasks:

• Develop system-level thermal hydraulic analysis methods, including modeling strategies, numerical approaches, and closure models.
• Perform steady-state and transient system-level analyses to characterize model behavior, assess method performance, and define method fidelity requirements.
• Support method qualification, including numerical verification, applicability envelopes, and performance characterization.
• Formulate and integrate closure models and empirical correlations (e.g., heat transfer, pressure drop, mixing, component-level physics) into existing analysis frameworks.
• Identify modeling gaps and support method enhancement using and sensitivity studies.
• Develop automated workflows and tools for model setup, execution, post processing, and repeatable method application
• Document modeling methodologies, assumptions, method applicability, and numerical performance for design processes and licensing support activities.
• Work across disciplines to ensure thermal hydraulic methods integrate effectively with plant design, safety analysis, and coupled simulation workflows.
• Apply and improve client's SQA and NQA 1 modeling practices, ensuring traceability, configuration control, and reproducibility of methods.

Key Qualifications and Skills:

• Degree in Mechanical, Nuclear, Chemical Engineering, or similar fields, with 6+ years of experience in system-level thermal hydraulic modeling and method development for nuclear or complex energy systems.
• Demonstrated experience in developing or improving analysis methods, including numerical scheme development, closure model formulation, and stability/accuracy optimization strategies.
• Experience performing system-level thermal hydraulic analyses using tools such as RELAP5 3D, GOTHIC, SAS, or equivalent, with the ability to extend or tailor modeling approaches within these frameworks.
• Strong foundation in thermal fluids and reactor system behavior, including complex thermal hydraulic phenomena relevant to advanced reactor designs.
• Experience in sensitivity analyses and model gap identification that support method development priorities.
• Familiarity with scientific programming and workflow automation (e.g., Python, MATLAB).
• Familiarity with NQA 1 quality assurance for modeling workflows, including documented methodologies, configuration control, and model traceability.
• Strong analytical thinking, clear technical communication, and the ability to support multiple method development efforts in parallel.
• Strong communication skills desired.
• The service provider will possess a high degree of trust and integrity, communicate openly and display respect, and a desire to foster teamwork.