Computational Fluid Dynamics Thermal-Hydraulics Engineer

Thanks for your interest in Oklo! We are searching for a Computational Fluid Dynamics (CFD) Thermal-Hydraulics Engineer to join our team.

Position Description

Thermal-Hydraulics Engineers at Oklo are responsible for analyzing fluid flow and heat transfer within a reactor and associated systems. This work includes engineering analyses of thermal-fluid dynamics, clear and thorough documentation of the analyses, as well as interfacing with design teams. A CFD Thermal-Hydraulics Engineer will be responsible for conducting high-fidelity thermal fluid simulations using commercial CFD tools.

Specific responsibilities may include:

• Developing and conducting high-fidelity analyses using CFD to analyze thermal-hydraulic behavior through the reactor core, reactor vessel, heat exchangers, power conversion, and balance of plant systems
• Proactively designing, modeling, and analyzing thermal hydraulic systemsDeveloping and utilizing analysis methods that efficiently and effectively build confidence in a design
• Performing engineering analyses, which can include thermal, fluid, safety, manufacturability, and cost
• Collaborating cross-functionally to define design requirements, and providing technical feedback to quick-iterating design teams
• Documenting work using modern tools and techniques, and writing well-written, thoughtful technical reports
• Providing technical feedback to quick-iterating design teams

Minimum Qualifications

• Bachelors, Masters, or PhD in a technical field, such as nuclear, mechanical, or aerospace engineering
• Proficiency with STAR-CCM+, ANSYS Fluent, OpenFOAM, Nek-5000, or equivalent
• Core competencies in heat transfer, fluid dynamics, and thermodynamics first principles 
• Experience with data processing (e.g., pre-processing, post-processing, scripting)

Bonus Qualifications

• Experience with thermal hydraulic engineering principles and multi-physics analysis methods for engineering applications, particularly as they relate to power systems
• Experience with nuclear engineering principles and multi-physics analysis methods for engineering applications, particularly as they relate to advanced reactors
• Experience with analysis of heat exchangers, turbomachinery, and fluid control systems
• Competency with modern software engineering practices and programming languages
• Fluency with Python
• Experience with reactor transient analysis methods
• Experience with systems or reactor safety codes such as GOTHIC, RELAP, TRACE, SAM, or SAS4A/SASSYS-1

Competencies:

We are looking for a CFD Thermal-Hydraulics Engineer that is:

• Passionate about clean energy
• Passionate about making advanced fission a reality
• Willing and able to learn quickly
• Skilled with CFD tools such as STAR CCM+, Fluent, or similar
• Experienced with thermal fluids analysis
• Eager to work on a dynamic team, receive constructive feedback, and grow with us
• Comfortable in a fast-paced, highly iterative environment
• Excited to think creatively, critically, and reflectively about the problems they are solving, while not leaning only on what has been done before 
• Excellent communicator of technical content both verbally and in writing

Who you are:

A startup person: You aren't driven by titles or hierarchy, and prefer efficiency to excess process. You don't need or expect to have a lot of guidance but you enjoy working in a fast-paced team. If you prefer the culture and feel of a large organization, that is great, but you likely won’t enjoy working with us! There is plenty of important work and plenty of good opportunities with organizations like that.

Motivated: You are self-motivated. You bring an enthusiasm to the team, and imbue a sense of passion that goes beyond clocking in and clocking out. This isn’t about a fake or arbitrary “pieces of flair” mentality or lack of work-life balance! It is about being a part of the vision and feeling a part of reaching team goals.

A team-player: Oklo genuinely is a team. We aren’t about taking credit for ourselves, and we aren’t about pushing blame to others. We do incredible things because we work as a team.

An excellent communicator: We need a person who is not only technically competent but also a clear and upbeat communicator.

Creative: Being creative means that when things fall outside clear scopes or processes or problems arise without clear solutions, you are able to identify it as well as invent ways to solve a problem or fill a need without micromanagement. The successful person in this job will not only be creative, but also enjoy being creative and solving open-ended problems which may change day-by-day.

Detail-oriented: This focus is a big part of excellence, consistency, and quality. Excellent grammar and spelling matter for both good communication as well as the image of the company that we put forward.

About Oklo travel requirements:

Oklo requires remote employees to travel to headquarters (Santa Clara, CA) twice a quarter annually, based on business or team needs, including attendance at team meetings, off-sites, and other company events or gatherings.

About Oklo Compensation: 

Salary: $73,000 - $157,000 base salary, performance incentives, and equity.

Salary may fall outside of the range provided and will be dependent on applicant experience.

Oklo offers flexible time off, equity, competitive pay, 401k, health insurance, FSA, flexible work hours, and other benefits.

About Oklo Inc.: Oklo Inc. is developing fast fission power plants to deliver clean, reliable, and affordable energy at scale; establishing a domestic supply chain for critical radioisotopes; and advancing nuclear fuel recycling to convert nuclear waste into clean energy. Oklo was the first to receive a site use permit from the U.S. Department of Energy for a commercial advanced fission plant, was awarded fuel material from Idaho National Laboratory, and submitted the first custom combined license application for an advanced reactor to the U.S. Nuclear Regulatory Commission. Oklo is also developing advanced fuel recycling technologies in collaboration with the U.S. Department of Energy and U.S. National Laboratories.

#CHOP: Oklo’s Values
Collaboration: We go further, together. We bring diverse perspectives, listen actively, and build trust through transparency and respect. We work across disciplines, sharing ownership to turn complex challenges into shared successes.
Humility: We are team players who act for the good of the company and for the world. We are focused on our mission, not personal recognition.
Ownership: We take pride in what we do and how we do it. We are proactive in finding solutions and see tasks through  to completion. We are committed to delivering on our promises to provide clean, reliable, and affordable energy.
Pathfinding: We chart new ground where no path exists by approaching challenges with curiosity, courage, and creativity while navigating ambiguity.

Recruitment Fraud Disclaimer

Oklo is aware of recent recruitment fraud attempts targeting job seekers. Please be cautious of anyone claiming to represent Oklo who does not contact you from an official Oklo email address.

All legitimate communications from our recruiting team— including application updates, interview requests, and job offers — will come exclusively from an Oklo email. Oklo will never ask for sensitive personal information, payments, or account credentials during the hiring process.

If you receive suspicious outreach or have concerns about the authenticity of any communication claiming to be from Oklo, please contact us through the official channels listed on our website.