Nuclear Thermal-Hydraulics Engineer

Subcritical Systems Inc; Austin (TX); On-site; USD 120,000 - 180,000; Full time

Benefits offered by this job

Healthcare insurance

Startup environment

Impactful work

Job summary

Subcritical Systems Inc. in Austin, TX, is hiring Nuclear/Mechanical Thermal-Hydraulics Engineers for full-time, on-site roles.

You will lead or support the design, simulation, prototyping, and procurement of thermal-hydraulic systems including a primary lead cooling loop and a passive decay heat removal system, contributing to the energy amplifier subcritical core. Ideal candidates hold an MS or BS in ME or related field with experience in nuclear thermal-hydraulics and CFD modelling.

Qualifications

• MS or BS in Mechanical Engineering or similar field.
• Experience in nuclear system thermal-hydraulics design and/or modeling.
• Experience using CFD codes to model heat transfer in nuclear systems.
• Record of technical accomplishment through publications and presentations.
• Strong work ethic, resilient, able to work in a fast-paced environment, driven, passionate about the field.
• Export control restrictions limit us to candidates who are U.S. citizens or U.S. permanent residents (green card holders).

Responsibilities

• Lead or support design and modeling of thermal-hydraulic systems: primary Pb loop, passive decay heat removal, intermediate cooling loop, Pb test loop.
• Perform design, FEA and CFD simulations of cooling systems and components.
• Study component options (pumps, heat exchangers) for baseline design.
• Lead or support design, construction and operation of a scaled Pb loop for testing components.
• Develop and document design, hardware specifications, interface requirements and procurement documents.
• Work with nuclear engineering team to optimize core design from a thermal-hydraulics standpoint.
• Collaborate with other teams to ensure systems meet performance requirements.
• Document work in reports, presentations, and regulatory submissions.

Skills

Thermal-hydraulics design

CFD simulations

Publications & presentations

Education

MS or BS in Mechanical Engineering

Tools

STAR-CCM+

SAS4A/SIMMER/RELAP

Job description

We are seeking to fill multiple nuclear thermal-hydraulics engineering roles leading and supporting the design of liquid metal cooling and passive decay heat removal systems for the subcritical core of an accelerator-driven Energy Amplifier.

About Subcritical Systems Inc.

Subcritical Systems Inc. is a funded startup based in Austin, Texas dedicated to bringing the energy amplifier concept to the United States for safe generation of electrical power. Using a particle accelerator to sustain fission of nuclear fuel in a subcritical core, our innovative approach aims to transform energy production. The founding team is comprised of entrepreneurs with a history of building cutting-edge technology companies and scientists from US national labs with deep experience in energy amplifier technologies. Subcritical Systems is venture-backed and actively hiring to expand its dynamic team, work towards licensing, regulatory submissions and construction of its first energy amplifier.

About the Role

We are seeking creative and dynamic Nuclear/Mechanical Thermal-Hydraulics Engineers to join our growing team in full-time, on-site roles located in Austin, TX. In this role you will lead or support the design, simulation, prototyping, and procurement of one or more thermal-hydraulic systems including primary lead cooling loop, passive decay heat removal system, intermediate cooling loop system, and scaled test loop for prototyping and qualifying components.

This is an ideal role for an ambitious, creative and hard-working engineer who wants to use their expertise to transform the energy system and in so doing change the world.

We cannot accept candidates who require visas/sponsorship at this time.

Responsibilities:

• Serve as an integral member of the subcritical fission system team responsible for designing, prototyping, and ultimately constructing the subcritical assembly.
• Lead or support design and modeling of one or more thermal-hydraulic systems: primary Pb loop, passive decay heat removal system, intermediate cooling loop and Pb test loop.
• Perform design, FEA and CFD simulations of cooling systems and components.
• Study available component options (pumps, heat exchangers, etc.) for adoption in the baseline design.
• Lead or support design, construction and operation of a scaled Pb loop to test scaled prototype components. Work with materials scientist staff to incorporate erosion and corrosion testing in the scaled Pb loop.
• Develop and document design, hardware specifications, interface requirements and procurement documents.
• Work closely with the nuclear engineering team to optimize the core design from a thermal-hydraulics standpoint.
• Work closely with other engineering team members responsible for designing the subcritical core and core vessel internals to ensure systems meet performance requirements.
• Work with the leadership team on developing & tracking key company technical milestones, ensuring delivery of results within aggressive timelines in a complex, fast-paced environment.
• Document work in written reports, presentations, and regulatory submissions.

About You:

• M.S. (preferred) or B.S. in Mechanical Engineering or similar field.
• Experience in nuclear system thermal-hydraulics design and/or modeling
• Experience using CFD code(s) to model heat transfer in nuclear systems.
• Record of technical accomplishment through publications and presentations.
• Strong work ethic, resilient, able to work in a fast-paced environment, driven, passionate about the field.
• Export control restrictions limit us to candidates who are U.S. citizens or U.S. permanent residents (green card holders).

Pluses:

• Experience using STAR-CCM+ to perform CFD simulations.
• Experience using SAS4A, SIMMER, RELAP, or similar reactor accident simulation codes.
• Experience performing thermal-hydraulic simulations with heavy liquid metal coolant.

What We Offer:

• A high-impact role where your work has real-world application in addressing the nation’s energy challenges via the development of truly forward-looking approaches and technology.
• Competitive salary commensurate with experience and technical expertise.
• Comprehensive healthcare insurance.
• The chance to work alongside world‑class entrepreneurs and well‑known scientific leaders.
• An opportunity to work in a fast‑paced startup environment.