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Salary: USD 150,000 - 200,000 / annual
Oklo is seeking a Thermal-Hydraulics and Safety Analysis Engineer to join its isotope engineering team and own the thermal-hydraulic safety case for next-generation domestic isotope production facilities.
You will be 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 role combines hands-on transient modeling using codes such as RELAP5 with safety-methodology development. You will establish modeling approaches, assess code and model applicability, quantify uncertainty, and produce clear, auditable technical documentation suitable for licensing applications and regulatory review.
Key responsibilities 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
- Develop event-specific analysis plans including initial and boundary conditions, assumptions, acceptance criteria, and uncertainty treatment
- Develop and document thermal-hydraulic safety-analysis methods, modeling guidance, and engineering practices for advanced reactor licensing
- Establish and justify code, model, and correlation applicability for physical phenomena and operating regimes
- Perform model verification, validation, sensitivity studies, uncertainty analyses, scaling evaluations, and comparisons with experiments and benchmarks
- Translate regulatory requirements and safety acceptance criteria into defensible analysis requirements
- Prepare high-quality calculation packages, methodology documents, safety-analysis reports, and licensing-application content
- Evaluate design changes and provide feedback on effects to transient response, safety margins, and licensing basis
- Collaborate with reactor physics, fuel, controls, mechanical, and licensing engineers on coupled analyses
- Develop scripts and automated workflows for model generation, execution, post-processing, and configuration control
- Review safety analyses and models prepared by internal contributors, vendors, and external partners
You will work closely with safety, licensing, reactor physics, thermal-hydraulics, controls, and system-design teams. The isotope engineering team is small but growing, so you must be capable of operating in a highly iterative and independent environment. 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.
Oklo requires remote employees to travel to headquarters (Santa Clara, CA) twice a quarter annually for team meetings, off-sites, and company events. The first two weeks of onboarding are required to be in person at headquarters.
About Oklo: 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.
**REQUIREMENTS:**
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 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
