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Reactor Engineer Jobs in California (NOW HIRING)

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 ...

Engineering Employment Type: Full Time Location: San Francisco Description Real-time video AI and ... You'll own design at Reactor end-to-end. That means defining the problem, exploring solutions ...

Software Engineer

Santa Clara, CA ยท On-site +1

$110K - $155K/yr

Build tools for reactor engineers to visualize, compare, and evaluate reactor designs and their physics * Integrate simulation tools into our analyses pipelines * Implement physics kernels to solve ...

Build tools for reactor engineers to visualize, compare, and evaluate reactor designs and their physics * Integrate simulation tools into our analyses pipelines * Implement physics kernels to solve ...

Senior Software Engineer

Santa Clara, CA ยท On-site

$160K - $200K/yr

Develop reactor optimization schemes and statistical experiments to inform design changes * Mentor other engineers, set technical direction, and contribute to building a strong engineering culture ...

Senior Software Engineer

Santa Clara, CA ยท On-site +1

$160K - $200K/yr

Develop reactor optimization schemes and statistical experiments to inform design changes * Mentor other engineers, set technical direction, and contribute to building a strong engineering culture ...

Showing results 21-40

Reactor Engineer information

See California salary details

$58.7K

$110.2K

$200.3K

How much do reactor engineer jobs pay per year?

As of Aug 11, 2026, the average yearly pay for reactor engineer in California is $110,170.00, according to ZipRecruiter salary data. Most workers in this role earn between $79,400.00 and $130,800.00 per year, depending on experience, location, and employer.

What is a reactor engineer?

Reactor Engineers are professionals who design, operate, and maintain nuclear reactors. They are responsible for ensuring the safe and efficient functioning of reactors used for power generation, research, or medical purposes. Their work involves monitoring reactor systems, conducting safety assessments, and developing procedures to prevent accidents. Reactor Engineers also analyze reactor performance data and collaborate with other engineers and scientists to optimize reactor operations.

What are some common challenges faced by reactor engineers during routine operations and how are they addressed?

Reactor Engineers often encounter challenges such as maintaining reactor stability, troubleshooting instrumentation issues, and ensuring compliance with strict safety protocols. These challenges are typically managed through continuous monitoring, collaboration with multidisciplinary teams (including safety, operations, and maintenance personnel), and adherence to established procedures. Proactive communication and regular training enable Reactor Engineers to respond effectively to unexpected events and maintain optimal reactor performance.

What are the key skills and qualifications needed to thrive as a reactor engineer, and why are they important?

To thrive as a Reactor Engineer, you need a solid background in nuclear engineering, reactor physics, and safety protocols, typically supported by a degree in nuclear engineering or a related field. Familiarity with simulation software, reactor monitoring systems, and safety certification such as Fundamentals of Engineering (FE) or Professional Engineering (PE) is often required. Strong analytical thinking, attention to detail, and effective communication skills help you solve complex technical problems and work within multidisciplinary teams. These skills ensure the safe, efficient, and regulatory-compliant operation of nuclear reactors, which is critical for both safety and energy production.

What is the difference between Reactor Engineer vs Nuclear Engineer?

AspectReactor EngineerNuclear Engineer
CredentialsBachelor's in Nuclear Engineering or related field; often requires licensing or certificationBachelor's or higher in Nuclear Engineering; may also require licensing
Work EnvironmentDesign, operate, and maintain nuclear reactors, often in power plants or research facilitiesResearch, develop, and improve nuclear systems, including reactors and radiation safety
Industry UsagePrimarily in power generation, naval propulsion, and research reactorsResearch institutions, government agencies, and industry R&D

Reactor Engineers focus on the operation and safety of nuclear reactors, ensuring they run efficiently and safely. Nuclear Engineers have a broader scope, including research, development, and design of nuclear systems. Both roles require similar educational backgrounds and certifications, but Reactor Engineers are more hands-on with reactor operation, while Nuclear Engineers often work on innovation and system improvements.

What are popular job titles related to Reactor Engineer jobs in California? For Reactor Engineer jobs in California, the most frequently searched job titles are:
What job categories do people searching Reactor Engineer jobs in California look for? The top searched job categories for Reactor Engineer jobs in California are:
What cities in California are hiring for Reactor Engineer jobs? Cities in California with the most Reactor Engineer job openings:
Infographic showing various Reactor Engineer job openings in California as of August 2026, with employment types broken down into 88% Full Time, 5% Part Time, 2% Temporary, and 5% Contract. Highlights an 86% Physical, 5% Hybrid, and 9% Remote job distribution, with an average salary of $110,170 per year, or $53 per hour.

Reactor Core Thermal Fluids Engineer

Oklo

Santa Clara, CA โ€ข On-site

$80K - $175K/yr

Other

Medical, Retirement

This job post hasย expired today.ย Applications are no longer accepted.


Job description

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

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 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 throughย  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.