Reactor Core Thermal Fluids Engineer
Oklo
| Company | Oklo |
| Category | Engineering |
| Location | Santa Clara |
| Remote | Remote |
| Employment | Not stated |
| Level | Not stated |
| Salary | Not stated by the employer |
| Posted | 6 Jun 2026 |
| Last verified | 3 Aug 2026 |
| Source | Employer ATS (greenhouse) |
Description
Thanks for your interest in Oklo! We are searching for a Thermal Fluids Engineer to join our Core Thermal-Hydraulics team.
Position Description
The Core Thermal-Hydraulics team at Oklo is responsible for analyzing fluid flow and heat transfer within a reactor core. The work includes engineering analyses of thermal-fluid dynamics, clear and thorough documentation of the analyses, as well as interfacing with design teams. A engineer on the team will contribute to the development, qualification, and validation of methods for modeling coolant flow within reactor cores using one-dimensional models, intermediate-fidelity subchannel models, and high-fidelity computational fluid dynamics models.
Specific responsibilities may include:
Modeling core thermal-hydraulic behavior using
subchannel codes such as DASSH, MOOSE-Subchannel, or COBRA-TF
one-dimensional systems codes such as SAS4A/SASSYS-1 or RELAP
first principles approaches and in-house flow network models
3-D computational fluid dynamics
Developing and documenting methods to analyze core thermal-hydraulic behavior at steady-state and during transients
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
Minimum Qualifications
Bachelors, Masters, or PhD in a technical field, such as nuclear, mechanical, or aerospace engineering
Proficiency with thermal fluids (thermal-hydraulics) analysis methods and first principles
Able to write clear and concise documentation
Experience with
low-fidelity and intermediate-fidelity (e.g., porous body and correlation-based) models for heat transfer and fluid flow
numerical methods and software development for heat transfer and fluid flow problems
data processing (e.g., pre-processing, post-processing, scripting)
Bonus Qualifications
Fluency with Python
Demonstrated success in qualification and validation of analyses
Experience with
CI/CD computing environments
reactor systems codes (RELAP or similar)
subchannel analysis codes (COBRA-TF or similar)
high-fidelity computational fluid dynamics analysis
Competencies
We are looking for a Thermal Fluids Engineer that is:
Willing and able to learn quickly
Deeply skilled in analysis of heat transfer and fluid flow in confined geometries
Eager to work on a dynamic team, receive constructive feedback, and grow with us
Excited to think creatively, critically, and reflectively about the problems they are solving
Familiar with the importance of high-quality documentation
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. For the first two weeks of onboarding, employees are required to be in person at headquarters in Santa Clara, CA.
About Oklo compensation:
Salary: $80,000-$175,000
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