Senior Thermal-Hydraulics Methods Engineer (Nuclear)

TerraPower; Bellevue (WA); On-site; USD 154,000 - 205,000; Full time

Benefits offered by this job

Competitive compensation

Medical and wellness benefits

Parental leave

401k plan

Generous PTO

Relocation assistance

Job summary

TerraPower seeks a Principal Engineer, Safety Methods to advance plant-scale thermal-hydraulic methods for the Natrium reactor. You will develop, qualify, and implement modeling approaches enabling robust predictions across operational and transient scenarios.

The role requires expertise in system-level thermal-hydraulics, closure model formulation, and numerics, plus experience with Python/MATLAB and QA practices to ensure traceability and reproducibility.

Qualifications

• Degree in Mechanical, Nuclear, Chemical Engineering, or similar field.
• 12+ years of experience in system-level thermal-hydraulic modeling and method development for nuclear or complex energy systems.
• Experience with RELAP5-3D, GOTHIC, SAS or equivalent tools.
• Familiarity with NQA-1 quality assurance for modeling workflows.

Responsibilities

• Develop plant-scale thermal-hydraulic analysis methods, including modeling strategies and closure models.
• Perform steady-state and transient system-level analyses to assess model fidelity.
• Develop and maintain method qualification plans with verification and applicability envelopes.
• Integrate closure models into existing analysis frameworks.
• Collaborate with test engineering to identify data needs for model formulation.

Skills

Thermal-hydraulic modeling

System-level analysis

Closure model development

Numerical methods

Python

MATLAB

Technical communication

Mentoring

Analytical thinking

Cross-functional collaboration

Education

Bachelor's in Mechanical/Nuclear/Chemical Engineering

Tools

RELAP5-3D

GOTHIC

SAS

Scientific programming

Job description

TerraPower seeks a Principal Engineer, Safety Methods to advance plant-scale thermal-hydraulic methods for the Natrium reactor. You will develop, qualify, and implement modeling approaches enabling robust predictions across operational and transient scenarios.

The role requires expertise in system-level thermal-hydraulics, closure model formulation, and numerics, plus experience with Python/MATLAB and QA practices to ensure traceability and reproducibility.