Senior Computational Fluid Dynamics Engineer

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

Position Description

The thermal-hydraulics group at Oklo is 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 Engineer in this group will be responsible for conducting high-fidelity thermal fluid simulations using commercial CFD tools. Level (Engineer III/Senior) will be determined by experience.

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

5 years or more CFD experience in an industrial setting

Competencies:

We are looking for a Senior 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. For the first two weeks of onboarding, employees are required to be in person at headquarters in Santa Clara, CA.

About Oklo Compensation:

Salary: $100,000 - $190,000

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

Oklo offers flexible time off, equity, bonuses, performance incentives, 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.

Candidates should be aware that employment may be contingent upon successful completion of a drug screening, and employees may be subject to drug testing at any time in accordance with company policy and applicable laws.

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.com 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.