Principal Engineer, Core Thermal Hydraulics Methods and Analysis

TerraPower LLC.; Bellevue (WA); On-site; USD 143,000 - 186,000; Full time

Benefits offered by this job

Competitive Compensation

Discretionary short‑term incentive

Comprehensive Medical and Wellness

Medical

Vision

Life and Disability

401k Plan

Generous PTO

Relocation Assistance

Professional and Educational Support

Job summary

TerraPower LLC in Bellevue, WA seeks a Principal Engineer to develop and apply thermal-hydraulic methods for reactor core analysis and validate with first-principles calculations. You will work with multidisciplinary teams on design challenges, testing programs, and reporting findings to leadership.

The role emphasizes independent technical judgment, mentoring, and technical leadership across systems. Strong writing and communication skills are essential in a high‑trust, safety‑critical

Qualifications

• Minimum of 6 years of related experience with Bachelor’s degree; or 3 years and a Master’s degree.
• PhD without commercial experience may be acceptable with relevant research or expertise.
• Code proficiency in Python or C++ is a plus.
• Experience with a nuclear systems code, or subchannel analysis code (RELAP, SASSYS, GOTHIC, VIPRE-01) is a plus.
• Demonstrated ability to participate on a multi-disciplinary team of engineers.
• Experience with analysis of nuclear reactor core subchannel analysis is a plus.
• Experience with low Prandtl number heat transfer analysis is a strong plus.
• Experience with high temperature thermal-fluid systems (sodium) is a plus.
• Creative thinker with strong analytical/problem solving skills.
• Ability to work on multiple tasks concurrently during a given work week.
• Excellent writing and communication skills.
• High degree of trustworthiness and integrity, and fostering teamwork.

Responsibilities

• Develop and apply thermal-hydraulic analysis methods, including steady state and transient one‑dimensional network hydraulic analyses, and identify strategies for validation.
• Computational analysis of in-core steady-state thermal hydraulic phenomena.
• Perform code benchmarking and validation analyses to support code qualification and methodology development.
• Perform calculations using first principles of heat transfer, fluid dynamics, and thermodynamics to support and validate analysis results.
• Integrate with other engineering groups performing aspects of component, system, fuel, and control system analysis and related thermal‑hydraulic testing.
• Support development of testing programs needed for reactor core & components.
• Lead complex engineering issues spanning systems or disciplines with independent judgment.
• Provide input to project planning by defining work scopes for the critical path.
• Lead cross-disciplinary teams to analyze safety-related design considerations.
• Provide technical presentations and leadership updates.
• Prepare informal and formal reports documenting findings and recommendations.
• Mentor and guide other engineers, establish technical direction, ensure quality and compliance.

Skills

Python/C++

Nuclear codes

Multi-disciplinary teamwork

Subchannel analysis

Low Prandtl number analysis

High temperature thermal-fluid (sodium

Analytical/problem solving

Task management

Written & verbal communication

Trust and integrity

Education

Bachelor’s degree; 6+ years exp

Master’s degree (3+ yrs exp)

PhD with relevant exp considered

Tools

RELAP

SASSYS

GOTHIC

VIPRE-01

Job description

Principal Engineer, Core Thermal Hydraulics Methods and Analysis

Bellevue, Washington, United States

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 a 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, TerraPower has instituted an Affittiative Action Plan (AAP) in an effort to proactively recruit, hire, and promote women, minorities, disabled persons and veterans.

The Principal Engineer reporting to the Manager of Core Thermal Hydraulics Methods and Analysis develops and applies thermal‑hydraulic analysis methods, performs code validation, applies first‑principles calculations, and integrates with multidisciplinary teams to solve reactor‑core design challenges and support testing programs. The role provides technical recommendations through formal documentation and presentations, requiring strong analytical skills, expertise with nuclear systems codes, and the ability to work concurrently across multiple complex tasks.

Responsibilities

• Develop and apply thermal-hydraulic analysis methods, including steady state and transient one‑dimensional network hydraulic analyses, and identify and implement strategies for validation of the analytical methods
• Computational analysis of in‑core steady‑state thermal hydraulic phenomena
• Perform code benchmarking and validation analyses to support code qualification and methodology development
• Perform calculations using first principles of heat transfer, fluid dynamics, and thermodynamics to support and validate analysis results
• Integrate with other engineering groups performing aspects of component, system, fuel, and control system analysis and related thermal‑hydraulic testing
• Support development of testing programs needed for reactor core & components
• Exercises independent technical judgment and decision‑making within delegated authority and leads the resolution of complex, high‑impact engineering issues that span systems or disciplines.
• Provide input to project planning through defining the work scopes for the critical path of the project
• Lead cross‑disciplinary teams to analyze the thermal and mechanical design considerations for the safety of the reactor and its components
• Provide technical presentations on analyses performed to the broader team, and provide periodic updates to leadership.
• Prepare informal and formal reports to document findings and make reasoned recommendations, and report to core thermal hydraulic team manager/lead
• Provides technical leadership by mentoring and guiding other engineers, establishing technical direction, and reviewing engineering work products to ensure technical rigor, quality, and compliance with applicable procedures.

Key Qualifications and Skills

• Minimum of 6 years of related experience with Bachelor’s degree; or 3 years and a Master’s degree. PhD without commercial experience may be acceptable with relevant research or expertise.
• Programming language proficiency in either python or C++ a plus
• Experience with a nuclear systems code, or subchannel analysis code (e.g. RELAP, SASSYS, GOTHIC, VIPRE‑01) a plus
• Demonstrated ability to participate on a multi‑disciplinary team of engineers
• Experience with analysis of nuclear reactor core subchannel analysis a plus
• Experience with low Prandtl number heat transfer analysis a strong plus
• Experience with high temperature thermal‑fluid systems (e.g. sodium) a plus
• Creative thinker with demonstrated strong analytical/problem solving skills
• Ability to work on multiple tasks concurrently during a given work week
• Excellent writing and communication skills
• The successful candidate will possess a high degree of trustworthiness and integrity, communicate openly and display respect and a desire to foster teamwork

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.

Job details

Salary Range: $143,101.00 - $185,846.00
Job Type: Full‑time

Benefits

• Competitive Compensation
• Salary, eligible to participate in discretionary short‑term incentive payments
• Comprehensive Medical and Wellness Benefits
• Medical
• Vision
• Life and Disability
• 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

Voluntary Self‑Identification

For government reporting purposes, we ask candidates to respond to the below self‑identification survey.Completion of the form is entirely voluntary. Whatever your decision, it will not be considered in the hiringprocess or thereafter. Any information that you do provide will be recorded and maintained in aconfidential file.

As set forth in TerraPower LLC.’s Equal Employment Opportunity policy,we do not discriminate on the basis of any protected group status under any applicable law.

If you believe you belong to any of the categories of protected veterans listed below, please indicate by making the appropriate selection.As a government contractor subject to the Vietnam Era Veterans Readjustment Assistance Act (VEVRAA), we request this information in order to measurethe effectiveness of the outreach and positive recruitment efforts we undertake pursuant to VEVRAA. Classification of protected categoriesis as follows:

A \"disabled veteran\" is one of the following: a veteran of the U.S. military, ground, naval or air service who is entitled to compensation (or who but for the receipt of military retired pay would be entitled to compensation) under laws administered by the Secretary of Veterans Affairs; or a person who was discharged or released from active duty because of a service‑connected disability.

A \"recently separated veteran\" means any veteran during the three‑year period beginning on the date of such veteran's discharge or release from active duty in the U.S. military, ground, naval, or air service.

An \"active duty wartime or campaign badge veteran\" means a veteran who served on active duty in the U.S. military, ground, naval or air service during a war, or in a campaign or expedition for which a campaign badge has been authorized under the laws administered by the Department of Defense.

An \"Armed forces service medal veteran\" means a veteran who, while serving on active duty in the U.S. military, ground, naval or air service, participated in a United States military operation for which an Armed Forces service medal was awarded pursuant to Executive Order 12985.