Criticality Safety Engineer Jobs (NOW HIRING)

Join us and make YOUR mark on the World!

Lawrence Livermore National Laboratory (LLNL) has turned bold ideas into world-changing impact advancing science and technology to strengthen U.S. security and promote global stability. 

Our mission spans four critical national security areas nuclear deterrence, threat preparedness, energy security, and multi-domain defense empowering teams to take on the toughest challenges of today and tomorrow. With a culture built on innovation and operational excellence, LLNL is a place where your expertise can make a real impact.

We have an opening for a Criticality Safety Engineer. You will contribute to the design, development, and testing of nuclear equipment and systems for Lawrence Livermore National Laboratory (LLNL) operations with fissionable materials.  You will also contribute to projects and task assigned to LLNL supporting the Department of Energy (DOE) Nuclear Criticality Safety Program.  This position is in the Nuclear Criticality Safety Division within the Environment, Safety, and Health (ES&H) Directorate.

This position will be filled at either level based on knowledge and related experience as assessed by the hiring team. Additional job responsibilities (outlined below) will be assigned if hired at the higher level.

This position requires full-time on-site presence due to the nature of the work.

You will 

• Perform criticality safety evaluations in conformance with DOE-STD-3007 and LLNL administrative procedures and participate in design and reviews of new or proposed changes to existing equipment or operating procedures.
• Perform walk-through inspections and basic annual reviews of operations and work authorization/work control documents and review safety procedures and documents for consistency with criticality safety evaluations and adequate implementation of criticality safety controls.
• Perform technical/scientific assignments of moderate to complex problems that require independent analysis and creativity, and provide technical support to facility management, engineers and scientists in scientific research and development projects and/or ongoing operations.
• Gather and analyze data and information in support of the work activity and deliver results in the form of documents, calculations, recommendations, corrective actions, or designs.
• Develop creative solutions to problems of moderate complexity, contributing to the fulfillment of project and organizational goals.
• Frequently travel to the Nevada National Security Sites.
• Conduct Fundamentals of Criticality Safety training courses.
• Perform other duties as assigned.

Additional job responsibilities, at the SES.3 level

• Prepare technical reports and present formal presentations to LLNL management and various internal and external audiences.
• Conduct formal on-the-job training, informal presentations, and complex consultations of criticality safety information to fissile material handlers, designers, and other clients.
• Interpret, implement, and provide guidance to internal customers on DOE regulations, national consensus criticality safety standards and Laboratory policies related to criticality safety.

• Ability to secure and maintain a U.S. DOE Q-level security clearance which requires U.S. citizenship.
• Bachelor's Degree in Nuclear Engineering, Physics, or closely related scientific discipline or the equivalent combination of education and related experience.
• Comprehensive knowledge of and experience working in a nuclear facility, nuclear reactor, chemical, high hazard, (e.g., explosive), radiological operations, or similarly complex or highly regulated facility.
• Broad application of technical, analytical and decision-making skills and record of achievement in performing criticality safety evaluations or research.
• Proficient with personal computers and radiation transport software (e.g., COG, MCNP, SCALE).
• Experience preparing technical documents following appropriate protocols (e.g., criticality safety evaluations, safety basis calculations, design calculations, and drawings/sketches).
• Working knowledge of DOE orders, national consensus standards, and engineering practices.
• Proficient verbal and written communication and interpersonal skills necessary to work effectively in a collaborative work environment.
• Ability to document, present and/or explain technical or operational information and work results to management and stakeholders, i.e., DOE, DNFSB, and other external agencies.

Additional qualifications at the SES.3 level

• Significant experience with nuclear and fissile material operations.
• Significant experience conducting safety evaluations in conformance with applicable DOE orders.

Qualifications We Desire

• Masters or Doctorate in Nuclear Engineering, Physics, or closely related discipline.
• Experience in criticality safety.
• Knowledge of LLNL's policies, procedures, and practices.

Pay Range: $146,340- $222,564 Annually

$146,340 - $185,544 Annually for the SES.2 level
$175,530 - $222,564 Annually for the SES.3 level

This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting.  An employee's position within the salary range will be based on several factors including, but not limited to, specific competencies, relevant education, qualifications, certifications, experience, skills, seniority, geographic location, performance, and business or organizational needs.

#LI-Onsite

Position Information

This is a Career Indefinite position, open to Lab employees and external candidates.

Why Lawrence Livermore National Laboratory?

• Included in 2026 Best Places to Work by Glassdoor!
• Flexible Benefits Package
• 401(k)
• Relocation Assistance
• Education Reimbursement Program
• Flexible schedules (*depending on project needs)
• Our values - visit https://www.llnl.gov/inclusion/our-values

Security Clearance

This position requires a Department of Energy (DOE) Q-level clearance.  If you are selected, we will initiate a Federal background investigation to determine if you meet eligibility requirements for access to classified information or matter. Also, all L or Q cleared employees are subject to random drug testing.  Q-level clearance requires U.S. citizenship. 

Pre-Employment Drug Test

External applicant(s) selected for this position must pass a post-offer, pre-employment drug test. This includes testing for use of marijuana as Federal Law applies to us as a Federal Contractor.

Wireless and Medical Devices

Per the Department of Energy (DOE), Lawrence Livermore National Laboratory must meet certain restrictions with the use and/or possession of mobile devices in Limited Areas. Depending on your job duties, you may be required to work in a Limited Area where you are not permitted to have a personal and/or laboratory mobile device in your possession.  This includes, but not limited to cell phones, tablets, fitness devices, wireless headphones, and other Bluetooth/wireless enabled devices.  

If you use a medical device, which pairs with a mobile device, you must still follow the rules concerning the mobile device in individual sections within Limited Areas.  Sensitive Compartmented Information Facilities require separate approval. Hearing aids without wireless capabilities or wireless that has been disabled are allowed in Limited Areas, Secure Space and Transit/Buffer Space within buildings.

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Please be aware of recruitment scams where people or entities are misusing the name of Lawrence Livermore National Laboratory (LLNL) to post fake job advertisements. LLNL never extends an offer without a personal interview and will never charge a fee for joining our company. All current job openings are displayed on the Career Page under "Find Your Job" of our website. If you have encountered a job posting or have been approached with a job offer that you suspect may be fraudulent, we strongly recommend you do not respond.

To learn more about recruitment scams: https://www.llnl.gov/sites/www/files/2023-05/LLNL-Job-Fraud-Statement-Updated-4.26.23.pdf

Equal Employment Opportunity

We are an equal opportunity employer that is committed to providing all with a work environment free of discrimination and harassment. All qualified applicants will receive consideration for employment without regard to race, color, religion, marital status, national origin, ancestry, sex, sexual orientation, gender identity, disability, medical condition, pregnancy, protected veteran status, age, citizenship, or any other characteristic protected by applicable laws.

Reasonable Accommodation

Our goal is to create an accessible and inclusive experience for all candidates applying and interviewing at the Laboratory.  If you need a reasonable accommodation during the application or the recruiting process, please use our online form to submit a request. 

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