---
title: 'Thermal-Hydraulics and Safety Analysis Engineer - Isotopes at Oklo'
canonical: 'https://feeny.ai/job/thermal-hydraulics-and-safety-analysis-engineer-isotopes-oklo-santa-clara-ca-hyedbbskj4h6'
type: 'job'
last_seen: '2026-10-19'
---

# Thermal-Hydraulics and Safety Analysis Engineer - Isotopes at Oklo

- **Company:** Oklo
- **Location:** Santa Clara CA, OR
- **Work type:** remote
- **Posted:** 2026-09-25
- **Last confirmed live:** 2026-10-19
- **Apply:** https://job-boards.greenhouse.io/oklo/jobs/6208066004

## Job description

Thanks for your interest in Oklo!  We are searching for a Thermal-Hydraulics and Safety Analysis Engineer to join our isotope engineering team to own the thermal hydraulic safety case for the next generation of domestic isotope production facilities.

Position Description

The Thermal-Hydraulics and Safety Analysis Engineer is responsible for developing and executing systems-level thermal-hydraulic analyses that support the safety case, design basis, and licensing of Oklo's reactor systems. This engineer will evaluate reactor and plant response during normal operation, anticipated operational occurrences, and postulated accident conditions using codes such as RELAP5 and other systems-analysis tools.

This role combines hands-on transient modeling with safety-methodology development. The engineer will establish modeling approaches, assess code and model applicability, quantify uncertainty, and produce clear, auditable technical documentation suitable for licensing applications and regulatory review. The engineer will work closely with safety, licensing, reactor physics, thermal-hydraulics, controls, and system-design teams to connect analysis assumptions and acceptance criteria to an evolving reactor design.

This position is focused on thermal-hydraulic safety analysis and licensing support. It does not own source-term, radiological-consequence, or severe-accident progression analysis, although collaboration with engineers performing those analyses may be required.

The isotope engineering team is a small but growing team, so the candidate must be capable of operating in a highly iterative and independent environment.

Specific responsibilities may include:

- Develop, maintain, and execute systems-level thermal-hydraulic models of reactor and plant behavior using RELAP5 or comparable analysis codes.

- Analyze normal operating conditions, anticipated operational occurrences, design-basis events, and selected beyond-design-basis conditions relevant to the thermal-hydraulic safety case.

- Develop event-specific analysis plans, including initial and boundary conditions, assumptions, acceptance criteria, figures of merit, and treatment of uncertainties.

- Develop and document thermal-hydraulic safety-analysis methods, modeling guidance, and engineering practices appropriate to advanced reactor licensing.

- Establish and justify code, model, and correlation applicability for the physical phenomena and operating regimes being evaluated.

- Perform model verification, validation, sensitivity studies, uncertainty analyses, scaling evaluations, and comparisons with experiments, benchmarks, hand calculations, or higher-fidelity analyses. Identify gaps in available methods, data, and validation evidence, and define practical plans to close those gaps.

- Translate regulatory requirements and safety acceptance criteria into defensible analysis requirements and technical evaluation strategies.

- Prepare high-quality calculation packages, methodology documents, safety-analysis reports, licensing-application content, and responses to regulator questions.

- Evaluate design changes and provide timely feedback on their effects on transient response, safety margins, system performance, and the licensing basis.

- Collaborate with reactor physics, fuel, controls, mechanical, thermal-hydraulics, safety, and licensing engineers on coupled analyses and interface conditions.

- Develop scripts and automated workflows for model generation, execution, post-processing, regression testing, and configuration control.

- Review safety analyses and models prepared by internal contributors, vendors, and external partners.

Minimum Qualifications:

- Bachelor's, master's, or doctoral degree in nuclear, mechanical, chemical, or aerospace engineering, or a closely related technical field.

- Five or more years of relevant experience in reactor thermal-hydraulics, nuclear safety analysis, reactor transient analysis, or a closely related field. A relevant advanced degree may substitute for a portion of the professional experience.

- Demonstrated experience developing and executing systems-level transient models using RELAP5.

- Strong foundation in heat transfer, fluid mechanics, thermodynamics, and reactor thermal-hydraulics.

- Experience defining and analyzing reactor transients or accident scenarios, including initial conditions, boundary conditions, equipment response, operator or control actions, and acceptance criteria.

- Experience evaluating the reasonableness and applicability of models, correlations, assumptions, and results rather than treating analysis software as a black box.

- Experience documenting engineering analyses in clear, reviewable technical reports or calculation packages.

- Ability to work independently while collaborating effectively across engineering and licensing disciplines.

- Experience with verification and validation, uncertainty quantification, sensitivity analysis, scaling, bias evaluation, or code applicability assessments.

- Familiarity with experiment design, separate-effects and integral-effects testing, benchmark problems, and the use of test data to validate analytical methods.

Bonus Qualifications:

- Experience supporting NRC or DOE licensing applications, audits, topical or methodology reports, requests for additional information, or other regulatory interactions.

- Fluency with Python or another language used for model automation, data analysis, visualization, and quality checks.

- Competency with modern software engineering practices, including version control, automated testing, reproducible computing environments, and continuous integration.

- Experience working under a nuclear quality-assurance program or with safety-related analysis software and records.

- Experience mentoring other analysts or providing technical review of safety-analysis work.

Competencies

We are looking for a Thermal-Hydraulics and Safety Analysis Engineer who is:

- Skilled at developing and interpreting systems-level reactor transient analyses.

- Able to connect thermal-hydraulic behavior, safety functions, acceptance criteria, and licensing conclusions.

- Methodical about verification, validation, uncertainty, configuration control, and technical documentation.

- Comfortable making conservative but technically defensible assumptions when information is incomplete.

- Able to distinguish important safety drivers from modeling detail that does not materially affect a conclusion.

- Comfortable explaining model limitations and uncertainty to designers, reviewers, and regulators.

- Collaborative and effective at working across safety, licensing, design, reactor physics, and analysis teams.

- Passionate about clean energy, and about making domestic supply of national-need and therapeutic isotope production a reality.

- Willing and able to learn quickly, think differently, and do things in new ways.

- Comfortable in a fast-paced, highly iterative startup environment.

- An excellent writer who can write in a modern active voice, and 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. 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:

The salary range for this position is $150,000 to $200,000, subject to experience level.

Oklo offers flexible time off, equity, bonuses, competitive pay, 401(k), health insurance (with employer contribution), HSA, FSA, flexible work hours, wellness credits, and other benefits.

This position may involve access to information subject to U.S. export control laws. Only applicants who meet the definition of a U.S. person under applicable laws may be eligible.

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.

## About Oklo

## Company Overview
- **One-liner**: Oklo is developing next-generation fast fission power plants to produce clean, reliable, and affordable energy at scale, starting with the Aurora reactor.
- **Entity Type**: Public (NYSE: OKLO) – completed SPAC merger with AltC Acquisition Corp. in May 2024.
- **Headquarters**: Santa Clara, California, USA
- **Founded**: 2013
- **Founders**: Jacob DeWitte (CEO) and Caroline Cochran

## Core Business
- **Industry**: Advanced nuclear energy / clean energy generation
- **Target Customers**: Utilities, large-scale energy consumers (data centers, industrial facilities), government (DOE, national labs), and communities seeking carbon-free baseload power.
- **Mission**: To deliver clean, reliable, and affordable advanced nuclear power to meet one of the planet’s most urgent challenges – abundant clean energy at a global scale.

## Products & Services
- **Aurora Powerhouse**: A compact fast fission reactor capable of producing up to 75 MWe of electrical power. Features inherent safety (walk-away safe, self-stabilizing), can run on fresh fuel or recycled nuclear waste, and is designed for cost-competitive deployment. Targets operation at Idaho National Laboratory (INL) from late 2027 to early 2028.
- **Advanced Nuclear Fuel Supply**: Oklo is developing fuel fabrication facilities under the DOE’s Fuel Line Pilot Projects to support its own reactors and the broader advanced reactor industry.
- **Critical Radioisotopes (via subsidiary Atomic Alchemy)**: Oklo’s fast reactors can produce life-saving medical and industrial radioisotopes as a co-product of fission.

## Market Standing
- **Valuation/Market Cap**: As of early 2025, market capitalization approximately ~$1.5–2.0 billion (fluctuating with public markets; latest SEC filings provide exact figures).
- **Key Metric**: Total funding raised prior to going public exceeded $50 million from private rounds. Post-SPAC, the company raised ~$300+ million from the merger trust and a PIPE. Annual revenue is not yet material (pre-revenue, pre-deployment).
- **Notable Investors/Partners**: DOE (Idaho National Laboratory site use permit, Reactor Pilot Program, fuel fabrication projects), AltC Acquisition Corp. (sponsor led by Sam Altman who also joined Oklo’s board), and institutional investors participating in the SPAC PIPE.
- **Growth Signals**: Secured DOE site use permit at INL (2019) and awarded EBR-II fuel for first Aurora core; completed NRC Phase 1 pre-application readiness assessment; selected for two DOE Reactor Pilot Projects; building three fuel-fabrication facilities; targeting first reactor operation 2027–2028. Team has grown significantly, with 52+ open roles as of mid-2025.

## Competitive Advantages
- **Proven Fast Reactor Heritage**: Liquid-metal-cooled, metal-fueled fast reactors have over 400 reactor-years of operating experience worldwide, including the EBR-II which demonstrated inherent safety and waste recycling for 30 years.
- **Waste-as-Fuel Capability**: Aurora can run on recycled nuclear waste (including from EBR-II), solving a major environmental challenge while reducing fuel costs – a capability only fast reactors offer.
- **Inherent Safety**: The reactor is self-stabilizing and self-controlling using passive natural forces, making it walk-away safe without need for active safety systems or backup power.
- **Cost Competitiveness**: Designed to achieve cost-competitive power across all generation technologies through compact design, simplified operations, and fuel flexibility.

## Strategic Focus
- **Deploy First Reactor**: Primary near-term goal is constructing and operating Aurora-INL at Idaho National Laboratory by late 2027–2028.
- **Licensing and Regulatory Pathway**: Continue NRC pre-application and formal licensing process for advanced reactor design; build regulatory precedent for fast reactors.
- **Fuel Supply Chain**: Establish advanced fuel fabrication capacity via DOE Fuel Line projects to secure fuel supply for Aurora and future customers.
- **Commercial Expansion**: Develop pipeline of additional Aurora deployments across the U.S. for utilities, data centers, and industrial customers seeking 24/7 carbon-free power.
- **Radioisotope Production**: Scale subsidiary Atomic Alchemy’s capability to produce critical medical isotopes as an additional revenue stream.

## Why Work Here
- **Mission-Driven Impact**: Directly work on solving one of the world’s most urgent challenges – providing clean, reliable, and affordable energy at scale.
- **Top‑5% Employee Satisfaction**: Oklo ranks in the top 5% of companies for employee satisfaction (Lattice Pulse survey).
- **Remote‑Friendly Culture**: Many roles are open to remote work (within the U.S.), with headquarters in Santa Clara, CA. Physical presence may be required for certain lab/field roles (Idaho Falls, ID and other sites).
- **Elite Benefits**: Comprehensive financial benefits (including equity ownership), encouraged work-life balance and flexibility, robust health & wellness programs, and long-term financial stability support.
- **Engineering Culture**: World-class team with backgrounds from aerospace, automotive, nuclear power, and tech; emphasis on collaboration, humility, pathfinding, innovation, and ownership. Values-driven environment focuses on doing what’s right for the mission and the team.
- **Growth Opportunities**: Rapidly growing company with 52+ open roles across engineering (mechanical, nuclear, software, hardware, test), fuel recycling, legal, finance, and operations. Opportunity to shape the future of energy.

## Sources
1. [oklo.com - About](https://www.oklo.com/about/default.aspx)
2. [oklo.com - Careers](https://oklo.com/careers/)
3. [oklo.com - Technology](https://oklo.com/technology/)
4. [job-boards.greenhouse.io - Oklo jobs](http://job-boards.greenhouse.io/oklo)
5. [oklo.com - Home/Overview](https://oklo.com/overview/default.aspx)

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