Senior Core Thermal-Hydraulics Engineer

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

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