Criticality Safety Engineer Jobs in California (NOW HIRING)

About the Company

General Matter is enriching uranium in America. 

Our goal is to design, build, and operate the world's lowest-cost enrichment services in the United States. 

Our mission is to restore America's ability to produce nuclear fuel-fuel that will power AI, advanced manufacturing, critical industries, and the next generation of nuclear reactors. 

Ultimately, our work will help power national ambitions and enable a high-energy society. 

We were incubated by Founders Fund, like Anduril and Palantir before us, and are backed by top-tier investors. Our lean, world-class team of engineers and operators is applying a first-principles approach to solving the problem of nuclear fuel production. 

We are a mission-driven company with a culture of urgency, accountability, and transparency. 

Help us build a high-energy society by making the cleanest, safest form of baseload energy the most affordable. 

About This Role

As Lead Nuclear Criticality Safety Engineer at General Matter, you'll build and lead the criticality safety program for a Part 70 fuel cycle facility from the ground up. Your criticality safety evaluations (CSEs) are a foundational input into our Integrated Safety Analysis (ISA), meaning the double-contingency approach, methodology, and technical judgment you establish now will shape how this facility operates for decades. This is a rare opportunity to set the criticality safety strategy for a next-generation enrichment facility rather than inherit one - and to do it at a company where your technical decisions have a direct line to whether we get licensed and operating on schedule.

We're especially looking for engineers who've done this before at an NRC-licensed Part 70 facility, or who bring deep DOE criticality safety experience and are ready to translate that rigor into the NRC licensing framework. If you've spent your career fitting criticality safety work into someone else's program and are ready to build the program instead, we encourage you to apply and lead this work at General Matter.

Responsibilities

• Own the criticality safety program end-to-end: set methodology, double-contingency strategy, and technical direction for the site.
• Develop and maintain nuclear criticality safety evaluations (CSEs) for processes involving fissile materials, and ensure CSE outputs are correctly integrated into the ISA as a foundational safety basis input.
• Perform criticality safety analyses using computational methods and tools (e.g., SCALE, MCNP) to assess system safety and regulatory compliance.
• Serve as the primary technical point of contact on criticality safety matters during NRC licensing interactions, license amendments, and inspections.
• Ensure compliance with NRC, DOE, and ANSI/ANS criticality safety standards and regulations, translating DOE-derived methodologies into the NRC regulatory framework where applicable.
• Mentor and provide technical review for other criticality safety engineers, setting the technical bar for the team as it grows.
• Conduct audits, inspections, and reviews of facility operations to identify and mitigate criticality safety risks.
• Collaborate with engineering, operations, and regulatory teams to implement effective safety measures.
• Provide technical guidance and training to personnel on criticality safety principles and procedures.
• Investigate criticality safety incidents and develop corrective actions as necessary.
• Maintain accurate documentation and records to support audits and regulatory reviews.

Basic Qualifications

• Evidence of exceptional ability (prior projects, portfolio of work, completed products, etc.).
• 8+ years of nuclear criticality safety experience, including direct authorship of criticality safety evaluations at a DOE or NRC-licensed facility.
• Bachelor's degree in Nuclear Engineering, Physics, or a related field.
• Strong knowledge of criticality safety regulations, standards, and methodologies (e.g., 10 CFR Part 70, ANSI/ANS-8 series), and the ability to bridge DOE and NRC frameworks where they differ.
• Proficiency in computational tools such as SCALE, MCNP, or similar software.
• Ability to perform trade studies and make clear recommendations using first principles and engineering fundamentals, even with partial information.
• Strong verbal and written communication skills, with the ability to convey technical information to regulators, operators, and leadership alike.
• Ability to obtain and maintain required security clearance and access authorization.

Preferred Skills and Experience

• Direct experience standing up or significantly revising a criticality safety program at an NRC-licensed Part 70 facility.
• DOE weapons complex or national laboratory experience (e.g., Y-12, Savannah River, Los Alamos, Pantex, Idaho National Laboratory) with demonstrated ability to translate that experience into an NRC licensing context.
• Certification as a Nuclear Criticality Safety Engineer (e.g., ANSI/ANS-8.24).
• Professional Engineer (PE) license, or ability to obtain one.
• Advanced degree in Nuclear Engineering, Physics, or a related field.
• Experience in a fast-paced engineering environment or a highly technical role requiring a resourceful, entrepreneurial approach to complete tasks within tight timeframes or budget constraints.

Additional Requirements

Ability to work extended hours and weekends as necessary.

Equal Opportunity Employer

General Matter is an Equal Opportunity Employer; employment with General Matter is governed on the basis of merit, competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

Compensation and Benefits

The base salary range for this role is $160,000-$230,000 annually.

Compensation bands are determined by role, level, location, and alignment with market data. Individual level and base pay is determined on a case-by-case basis and may vary based on job-related skills, education, experience, technical capabilities and internal equity. Please note that the stated salary range is an estimate and may be adjusted based on market conditions, business needs, or other factors. In addition to base salary, for full-time hires, you may also be eligible for long-term incentives, in the form of stock options, and access to medical, vision & dental coverage as well as access to a 401(k) retirement plan.