Principal Engineer, Thermal Hydraulics

Bellevue, Washington, United States | Natrium | Full-time

Apply by: Oct. 8, 2025
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TITLE:                Principal Engineer, Thermal Hydraulics

LOCATION:     Bellevue, WA, USA  

TerraPower is a nuclear technology company based in Bellevue, Washington. At its core, the company is working to raise living standards globally through a more affordable, secure and environmentally friendly form of nuclear energy along with innovations in medical isotopes to improve human health. In 2006, TerraPower originated with Bill Gates and a group of like-minded visionaries who evaluated the fundamental challenges to raising living standards around the world. They recognized energy access was crucial to the health and economic well-being of communities and decided that the private sector needed to take action and create energy sources that would advance global energy deployment. TerraPower’s mission is to be a world leader in new nuclear technologies, while developing innovators and future leaders in the nuclear field. As a result, the company’s activities in the fields of nuclear energy and related sciences are yielding significant innovations in the safety and economics of nuclear power, hybrid energy and medical applications – all for significant human health benefits.

TerraPower is seeking to hire highly motivated and forward-thinking professionals who are interested in focusing on advanced nuclear reactor research and development and influencing change within the nuclear power landscape and bringing forward the critical production of medical isotopes.  TerraPower 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. In addition, as a federal contractor, TerraPower has instituted an Affirmative Action Plan (AAP) in an effort to proactively recruit, hire, and promote women, minorities, disabled persons and veterans.

Principal Engineer, Thermal Hydraulics

TerraPower, LLC. is seeking to contract with a highly capable and motivated Thermal Hydraulics Engineer to support analysis and design efforts of thermal-fluid and energy systems for the liquid sodium-cooled Natrium Reactor Program. Reporting to the Manager, System Thermal Hydraulics Methods & Analysis, you will perform investigations and analyses of thermal hydraulics, fluid dynamics, and fluid - structural interactions for this advanced and innovative energy system. Ideal candidates will have background and experience in running more than one commercial Computational Fluid Dynamics (CFD) code, as well as steady and transient hydraulic network analysis.

Responsibilities

    Performing analysis and design of structures, systems, and components for the Natrium Reactor

    Computational thermal-fluid and thermal-structural analysis using multi-dimensional CFD tools

    Perform steady state and transient hydraulic network analysis

    Document and present results to peers and outside organizations

    Support continuous learning and application of nuclear industry best practices in order to maintain the highest quality of engineering design and proactively identify process change/enhancement opportunities

    Work with cross-disciplinary teams to analyze the thermal and mechanical design considerations for the reactor and its components

    Work on complex issues where judgment in selecting methods, techniques, and evaluation criteria for obtaining results with minimal supervision

    Mentor less experienced staff to support their growth

Key Qualifications and Skills

    Degree in Mechanical, Nuclear, or Chemical engineering (or equivalent) with 10 plus years in the field of Computational Fluid Dynamics. Preferred, M.S. Degree in Mechanical, Nuclear, or Chemical engineering (or equivalent) with 8 plus years in the field of Computational Fluid Dynamics

    Minimum of 5 years of demonstrated use commercial CFD package (STAR-CCM+ preferred)

    Working knowledge of variety CFD best practices, modeling approaches, meshing parameters to be suited for specific applications balancing accuracy, computer resources.

    Experience with modeling dynamic thermal fluid systems

    Experience with one or more CAD modeling tools such as SolidWorks preferred

    Experience with nuclear systems applications of Computational Fluid Dynamics a plus

    Experience with analysis of high temperature thermal-fluid systems a plus

    Experience with low Prandtl number fluid heat transfer a plus

    Familiarity and experience with CFD verification and validation of computational modeling methodologies a plus

    Experience in Software Quality Assurance (SQA) program and Nuclear Quality Assurance (NQA-1) standards highly preferred

    Creative thinker with demonstrated strong analytical/problem solving skills

    Ability to work on multiple tasks concurrently during a given work week

    Strong communication skills desired

    The successful candidate will possess a high degree of trust and integrity, communicate openly and display respect, and a desire to foster teamwork

    Actual position starting level and title will be determined based on assessment of qualifications.

Job Functions

Job Functions are physical actions and/or working conditions associated with the position.  These functions may also constitute essential functions for the job which the employee must be able to fulfill, with or without accommodation.  Information provided below is to help describe the job so that the applicant has a reasonable understanding of the job duties/expectations.  An applicant's ability to perform and/or tolerate these actions and conditions will be discussed and workplace accommodations may be made on a case-by-case basis following an individualized assessment of the applicant and other considerations, including but not limited to any governing safety standards.

    Motor Abilities: Sitting and/or standing 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 hrs./day

    Travel required: 0-5%

TerraPower’s technology is controlled for export by various agencies of the U.S. Government.  TerraPower must evaluate applicants who are foreign nationals (other than asylees, refugees, or lawful permanent residents) in accordance with U.S. Government export control requirements.  To facilitate TerraPower’s export control reviews, you will be asked as part of the application process to identify whether you are a U.S. Citizen or national, asylee, refugee, or lawful permanent resident of the United States.  Government export authorization approval times vary.  Based on the business needs for a particular position, TerraPower will not consider a foreign national from a country if it is impracticable to obtain timely Government export approval.  

Job details

Salary Range Level 11:  $125,257 - $208,762

Salary Range Level 12:  $169,922 - $235,464

*Typically, our employee salaries are within .90 – 1.0 of the mid-point of the posted salary band. Any salary offered within the posted salary band is based on market data and commensurate with the selected individual’s qualifications and experience.  This range is specific to Washington State.

Job Type:  Full-time

Benefits:

    Competitive Compensation

    Salary, eligible to participate in discretionary short-term incentive payments

    Comprehensive Medical and Wellness Benefits

    Medical

    Vision

    Dental

    Life

    Life and Disability

    Gender Affirmation Benefits

    Parental Leave

    401k 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

    Flexible Work Schedule

 TerraPower Career and Benefits information:  https://www.terrapower.com/contact-us/careers/

 

Please visit www.terrapower.com to apply