Principal Engineer, Plant Thermal Hydraulics Methods

Principal Engineer, Plant Thermal Hydraulics Methods

Bellevue, WA, USA

Terra Power is seeking highly motivated professionals to work on advanced nuclear reactor research. This role supports the development, enhancement, and deployment of plant‑scale thermal‑hydraulic analysis methods and models for the Natrium reactor. The principal engineer reports to the Manager, Plant Thermal Hydraulics Methods and will support the creation, improvement, and qualification of advanced system‑level modeling approaches that enable accurate, robust predictions of plant behavior across operational and transient scenarios.

Terra Power is an Equal Opportunity Employer. We do not discriminate in hiring on the basis of sex, gender identity, sexual orientation, race, color, religious creed, national origin, physical or mental disability, protected veteran status, or any other characteristic protected by federal, state or local law.

• Develop plant‑scale 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.
• Develop and maintain method qualification plans, including numerical verification, applicability envelopes, and performance characterization.
• Formulate and integrate closure models and correlations (e.g., heat transfer, pressure drop, mixing, component‑level physics) into existing analysis frameworks.
• Identify modeling gaps and drive method enhancement priorities using the Phenomena Identification and Ranking Table (PIRT), sensitivity studies, and multi‑physics needs.
• Develop automated workflows and tools for model setup, execution, post‑processing, and repeatable method application.
• Collaborate with test engineering to define data needs that inform method development (not for validation purposes, but to guide model formulation and closure development).
• 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 Terra Power’s SQA and NQA 1 modeling practices, ensuring traceability, configuration control, and reproducibility of methods.
• Mentor junior engineers in numerical method development, system modeling, and modern computational analysis practices.

• Degree in Mechanical, Nuclear, Chemical Engineering, or a similar field, with 8+ 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.

• Motor Abilities:
  Sitting for extended periods, bending/stooping, grasping/gripping, fine motor control (hands).
• Physical exertion and/or requirements:
  Minimal, with ability to safely lift up to 25 pounds.
• Repetitive work:
  Prolonged.
• Special senses:
  Visual and audio focused work.
• Work conditions:
  Stairs, typing/keyboard, standard and/or sitting working environment of >8 hours/day.
• Travel required:
  
  0–10%.

• Salary Range Level 12: $168,316 – $252,475 (Washington State).
• Job Type: Full‑time.
• Benefits:
  • Competitive Compensation and discretionary short‑term incentive payments.
  • Comprehensive Medical and Wellness Benefits:
  • Medical, Vision, Dental, Life and Disability, Gender Affiliation Benefits.
  • Parental Leave.
  • 401(k) Plan.
  • Generous Paid Time Off (PTO): 21 days of annually accrued PTO.
  • Generous Holiday
    
    Schedule:
    
    10 paid holidays.
  • Relocation Assistance.
  • Professional and Educational Support Opportunities.

Equal employment opportunity, including veterans and individuals with disabilities.