Core Thermal-Hydraulics Methods Engineer

Thanks for your interest in Oklo!  We are searching for a Core Thermal-Hydraulics Methods 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 Core Thermal-Hydraulics Methods Engineer will contribute to the development, qualification, and validation of methods for modeling coolant flow within reactor cores using one-dimensional models and intermediate-fidelity subchannel models.

Specific responsibilities may include:

• Modeling core thermal-hydraulic behavior using
• subchannel codes such as DASSH, or MOOSE-Subchannel
• one-dimensional systems codes such as SAS4A/SASSYS-1 or SAM
• first principles approaches and in-house flow network models
• Developing methods to analyze core thermal-hydraulic behavior at steady-state and during transients
• Developing and utilizing analysis methods that efficiently and effectively build confidence in a design
• Automation, verification, and validation of modeling and simulation tools in support of analyses
• Collaborating cross-functionally to define design requirements, and providing technical feedback to quick-iterating design teams
• Document work using modern tools and techniques, and write well-written, thoughtful technical reports

Minimum Qualifications

• Bachelors, Masters, or PhD in a technical field, such as nuclear, mechanical, or aerospace engineering
• Proficiency with thermal-hydraulics (thermal fluids) analysis methods
• Core competencies in heat transfer, fluid dynamics, and thermodynamics first principles
• Experience with low-fidelity and intermediate-fidelity (e.g., porous body and correlation-based) models for heat transfer and fluid flow
• Experience with numerical methods and software development for heat transfer and fluid flow problems
• Experience with data processing (e.g., pre-processing, post-processing, scripting)

Bonus Qualifications

• Fluency with Python
• Experience with CI/CD computing environments
• Experience with reactor systems codes, such as SAS4A/SASSYS-1, SAM, RELAP, TRACE, or GOTHIC
• Experience with qualification and validation of analyses
• Experience with subchannel analysis codes, such as DASSH, MOOSE-Subchannel, COBRA-TF, or similar
• Experience with high-fidelity computational fluid dynamics analysis

Competencies

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

• Passionate about clean energy
• Passionate about making advanced fission a reality
• Willing and able to learn quickly
• Knowledgeable about the fluid physics related to reactor cores and subchannel-level thermal-hydraulic (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
• An excellent writer who can write in modern active voice, so make your cover letter compelling and write it well!
• Able to communicate technical content and results verbally

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. Even 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. Some travel to other sites is also required for this position. 

About Oklo compensation:

Salary: $73,000-$157,000

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.