Principle Engineer, Core Mechanical Test

TerraPower LLC.•Bellevue, WA

16h•$168,316 - $252,475•Onsite

About The Position

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. Principal Core Mechanical Engineer The Principal Core Mechanical Engineer will serve as a senior technical leader supporting mechanical development and validation for reactor core components and associated systems. The role includes designing and overseeing test programs, performing root‑cause investigations, coordinating vendor activities, ensuring high‑quality documentation, and driving technical decision‑making. The engineer will leverage advanced mechanical testing techniques, data analysis, and system‑level engineering to ensure the performance, reliability, and safety of mechanical systems critical to TerraPower’s reactor programs.

Requirements

12+ years of relevant engineering experience with a B.S. degree; or equivalent experience with an advanced degree.
Degree in Mechanical Engineering or a directly related technical discipline.
Demonstrated hands‑on mechanical testing or system development experience.
Strong background in mechanical system behavior including force/displacement application, structural deflection, dynamic loading, vibration/impact, and environmental exposure.
Experience working in the nuclear industry or in a regulated environment requiring compliance with standards such as 10CFR50, ASME NQA‑1, or similar nuclear quality and safety programs.
Experience working with large, complex mechanical systems strongly preferred.
Experience in project management strongly preferred.
Experience with multiple types of testing (R&D, acceptance, validation, qualification).
Experience performing, documenting, and post‑processing mechanical experiments.
Ability to lead complex projects with multiple technical objectives and resolve conflicts between competing priorities.
Experience coordinating with vendors or external partners for fabrication and testing.
Ability to operate within a lightly structured environment requiring first‑principles engineering.
Ability to perform advanced structural analysis using ANSYS, including nonlinear behavior, dynamic loading scenarios, thermal‑mechanical coupling, and verification of complex core mechanical components; highly desired.
Familiarity with engineering tools such as SolidWorks, LabVIEW, AutoDesk, Jira/Confluence, and Microsoft Office 365 preferred.
High level of integrity, communication skills, and a strong desire to foster teamwork.
This position is subject to qualification requirements in accordance with ANSI/ANS 3.1. Candidates must meet the minimum education and experience criteria applicable to the role, including relevant nuclear industry experience where required. Verification of data will be part of the hiring process.

Nice To Haves

Experience working with large, complex mechanical systems strongly preferred.
Experience in project management strongly preferred.
Ability to perform advanced structural analysis using ANSYS, including nonlinear behavior, dynamic loading scenarios, thermal-mechanical coupling, and verification of complex core mechanical components; highly desired.
Familiarity with engineering tools such as SolidWorks, LabVIEW, AutoDesk, Jira/Confluence, and Microsoft Office 365 preferred.

Responsibilities

Lead development, execution, and documentation of mechanical test plans, design specifications, and validation strategies for reactor core mechanical systems.
Apply quantitative, statistical, and engineering analysis techniques to evaluate test outcomes, identify root causes, and drive data‑based conclusions.
Develop and oversee complex mechanical testing campaigns from concept through execution and final reporting.
Translate conceptual requirements into detailed mechanical test specifications, including design inputs, instrumentation strategies, and success criteria.
Define, select, and validate measurement instrumentation (force, displacement, strain, temperature, vibration, loading, etc.).
Coordinate cross‑functional activities including fixture design, control system integration, and laboratory or facility planning.
Lead troubleshooting, failure analysis, and optimization of mechanical components and systems.
Collaborate across teams to address technical challenges related to reactor core mechanical behavior, system integration, and experimental analysis.
Provide oversight and coordination with vendors for procurements, specialized testing, and fabrication partnerships.
Support safe execution of mechanical testing activities while following TerraPower processes and Washington State regulations.
Communicate project status, risks, technical outcomes, and recommended paths forward to leadership and stakeholders.
Mentor junior engineers and contribute to developing best practices for mechanical testing and system analysis.