Thermal-Hydraulics Engineer

Thanks for your interest in Oklo! We are searching for a Thermal-Hydraulics Engineer to join our team.

Position Description

Thermal-Hydraulics Engineers are responsible for playing a crucial role in the design, analysis, and development of our fast reactor systems. You will be responsible for performing thermal-hydraulics analyses, utilizing state-of-the-art codes and methods, and contributing to the qualification and validation of our nuclear thermal-hydraulics analysis tools.

Specific responsibilities may include:

• Modeling thermal-hydraulic systems using codes such as SAS4A/SASSYS-1, SAM, GOTHIC, or Flomaster
• Performing subchannel analysis using codes such as MOOSE-Subchannel or DASSH
• Developing analytical and computational methods and models for core and systems thermal hydraulics
• Participating in verification and validation of nuclear thermal hydraulics analysis tools
• Collaborating cross-functionally to define design requirements and provide technical feedback to quick-iterating design teams
• Documenting work using modern tools and techniques, and write well-written, thoughtful technical reports

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.

Minimum Qualifications:

• Bachelor's, Master's, or Ph.D. in Nuclear Engineering, Mechanical Engineering, or a related field
• Proficiency with thermal-hydraulics (thermal fluids) analysis methods
• Core competencies in heat transfer, fluid dynamics, and thermodynamics first principles
• Strong problem-solving skills and the ability to work effectively in a collaborative team environment
• Excellent written and verbal communication skills

Bonus Qualifications:

• Proficiency in one or more of the mentioned analysis codes (SAS4A/SASSYS-1, SAM, GOTHIC, Flomaster, MOOSE-SC, DASSH) or similar (TRACE, RELAP, COBRA-TF)
• Familiarity with methods development, code qualification, and verification/validation processes in nuclear thermal hydraulics
• Competency with modern software engineering practices and programming languages
• Experience with CI/CD computing environments
• Experience with high-fidelity fluid dynamics analysis

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

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.

We are looking to fill this position immediately!

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.