Senior Engineer, Safety Methods

TerraPower LLC.•Bellevue, WA

6d•$131,828 - $171,206•Onsite

About The Position

TerraPower is a nuclear technology company focused on developing advanced nuclear energy and medical isotope innovations. The company aims to raise global living standards through affordable, secure, and environmentally friendly nuclear energy. TerraPower is seeking motivated professionals interested in advanced nuclear reactor research and development, influencing the nuclear power landscape, and contributing to medical isotope production. The Senior Engineer, Safety Methods position is part of a team supporting the design and licensing of the Natrium Demonstration reactor, with a primary focus on developing methods for Licensing Basis Events (LBE) analyses. The role may also involve contributing subject matter expertise to other projects within the TerraPower Sodium Fast Reactor (SFR) Program, including closure model formulation, system transient codes development and maintenance, reactor transient analyses, code benchmarking, scaling analysis, software commercial-grade dedication, code assessment and adequacy evaluation, and verification and validation activities. The Senior Engineer reports to the Manager of Plant Thermal Hydraulics Methods within the TerraPower SFR Program.

Requirements

Degree in Mechanical, Nuclear, Chemical Engineering, or similar fields, with 3+ years of experience in system-level thermal hydraulic modeling and method development for nuclear or complex energy systems.
Demonstrated experience in developing or improving analysis methods, including numerical scheme development, closure model formulation, and stability/accuracy optimization strategies.
Experience performing system-level thermal hydraulic analyses using tools such as RELAP5 3D, GOTHIC, SAS, or equivalent, with the ability to extend or tailor modeling approaches within these frameworks.
Strong foundation in thermal fluids and reactor system behavior, including complex thermal hydraulic phenomena relevant to advanced reactor designs.
Experience in sensitivity analyses and model gap identification that support method development priorities.
Familiarity with scientific programming and workflow automation (e.g., Python, MATLAB).
Familiarity with NQA 1 quality assurance for modeling workflows, including documented methodologies, configuration control, and model traceability.
Strong analytical thinking, clear technical communication, and the ability to support multiple method development efforts in parallel.
Possess a high degree of trust and integrity, communicate openly and display respect and a desire to foster teamwork.
Meet minimum education and experience criteria applicable to the role, including relevant nuclear industry experience where required.

Responsibilities

Develop system-level thermal hydraulic analysis methods, including modeling strategies, numerical approaches, and closure models.
Perform steady-state and transient system-level analyses to characterize model behavior, assess method performance, and define method fidelity requirements.
Support method qualification, including numerical verification, applicability envelopes, and performance characterization.
Formulate and integrate closure models and empirical correlations (e.g., heat transfer, pressure drop, mixing, component-level physics) into existing analysis frameworks.
Identify modeling gaps and support method enhancement using and sensitivity studies.
Develop automated workflows and tools for model setup, execution, post processing, and repeatable method application.
Document modeling methodologies, assumptions, method applicability, and numerical performance for design processes and licensing support activities.
Work across disciplines to ensure thermal hydraulic methods integrate effectively with plant design, safety analysis, and coupled simulation workflows.
Apply and improve TerraPower’s SQA and NQA 1 modeling practices, ensuring traceability, configuration control, and reproducibility of methods.