Senior Engineer, Plant Thermal Hydraulic Methods

Location: Bellevue, WA | Type: Contract | Work Model: Remote – offsite

Overview

System One is seeking a Senior Engineer, Plant Thermal Hydraulic Methods to support our client on a contract basis.

Responsibilities

• 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 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 SQA and NQA 1 modeling practices, ensuring traceability, configuration control, and reproducibility of methods.

Requirements

• Degree in Mechanical, Nuclear, Chemical Engineering, or similar fields.
• 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.
• 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; high degree of trust and integrity, open communication, respect, and teamwork orientation.

Pay

From $56.00 to $95.00 per hour

Benefits

• Health and welfare benefits coverage options including medical, dental, vision, and spending accounts.
• Life insurance and voluntary plans.
• Participation in a 401(k) plan.