Nuclear Criticality Safety Engineer
Content + Source + Freshness • 14 Dec 2025 • 95% confidence
Offer value
High value due to the critical nature of the role in nuclear safety, competitive compensation, and potential for impact in renewable energy.
- Competitive salary: $85,000–$165,000/year
- Key role in nuclear safety and innovation
- Dynamic and growth-oriented startup environment
- Requires specialized knowledge in nuclear safety
Pros
- Attractive salary range ($85k - $165k), competitive within the nuclear engineering sector
- Significant role impacting nuclear energy safety and innovation
- Dynamic startup environment with growth potential
Cons
- Requires specialized experience and knowledge in nuclear safety evaluations
- Limited guidance in a fast-paced startup might not align with everyone
- Potentially high-stress environment due to safety implications
Who it's for
Mid to Senior level • Remote
Good fit
- Nuclear engineers with criticality safety experience
- Self-motivated professionals thriving in a startup culture
- Individuals passionate about sustainable energy solutions
Not recommended for
- Entry-level job seekers without relevant experience
- Candidates seeking highly structured corporate roles
- Individuals averse to working in dynamic and challenging settings
Motivation fit
Key skills
About the job
Thanks for your interest in Oklo! We are searching for a nuclear criticality safety engineer to join our engineering team.
Position Description:
A nuclear criticality safety engineer at Oklo is responsible for performing criticality safety evaluations for nuclear reactor and fuel cycle facilities.
Specific responsibilities may include:
- Identifying and evaluating nuclear criticality safety (NCS) hazards for fuel cycle facilities
- Performing criticality safety evaluations (CSEs) to demonstrate subcriticality under normal and credible abnormal conditions
- Developing the criticality code validation report
- Demonstrating compliance with the double-contingency principle
- Documenting criticality hazard analyses, CSEs, and supporting technical information
- Evaluating and implementing controlled parameters for the NCS program
- Developing the criticality accident alarm system and inadvertent criticality emergency response plan
- Performing radiation shielding analysis to demonstrate adequate radiation mitigation
- Supporting development of shielding systems
- Supporting safety basis development and licensing efforts
- Administering the NCS program, methodologies, and management measures
Competencies:
- Knowledge of nuclear science, physics of criticality, and chemistry
- Knowledge of the nuclear fuel cycle and nuclear fuel cycle facility accident scenarios
- Ability to perform criticality calculations by hand or using criticality codes (e.g., SCALE, MCNP) for CSEs
- Familiarity with critical experiments and their purpose
- Knowledge of criticality-specific codes, standards, regulatory requirements, and industry practices for nuclear fuel cycle facilities
Minimum Qualifications:
- Bachelors, Masters, or PhD in nuclear engineering, chemical engineering, or chemistry
- Experience performing CSEs as a part of a nuclear facility safety basis
- Proficient with MCNP and SCALE codes
Bonus Qualifications:
- 3+ years of experience performing criticality safety evaluations for an NRC licensed fuel cycle facility
- Familiarity with NUREG-1513, NUREG-1520, NUREG/CR-6410, NUREG/CR-6698, and NRC RG 3.71
- Familiarity with ANSI/ANS-8 national standards
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 compensation:
$85,000-$165,000 annually.
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. (NYSE: OKLO) is a fast fission clean power technology and nuclear fuel recycling company developing fast fission power plants to provide clean, reliable, and affordable energy at scale. Oklo received a site use permit from the U.S. Department of Energy, was awarded fuel material from Idaho National Laboratory, submitted the first advanced fission custom combined license application to the Nuclear Regulatory Commission, and is developing advanced fuel recycling technologies in collaboration with the U.S. Department of Energy and U.S. National Laboratories.
