Principle Engineer, Core Mechanical Test

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.

About the role

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.

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.

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.

Job Functions

• 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%.

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 may not consider a foreign national from a country if it is impracticable to obtain timely Government export approval.

Pay

Salary Range $168,316 - $252,475. Any salary offered within the posted salary band is based on market data and commensurate with the selected candidate's qualifications and experience. This range is specific to Washington State.

Benefits

• Competitive Compensation: Salary, eligible to participate in discretionary short-term incentive payments.
• Comprehensive Medical and Wellness Benefits:
  • Medical
  • Vision
  • Dental
  • 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