Nuclear Criticality Safety Research Staff Member

Lawrence Livermore National Laboratory; Livermore (CA); On-site; USD 146,000 - 223,000; Full time

Job summary

Lawrence Livermore National Laboratory (LLNL) is seeking a Nuclear Criticality Safety Research Staff Member in the Nuclear Criticality Safety Division of the Environment, Safety, and Health Directorate. The role focuses on design, modeling, and analysis of critical and subcritical experiments in a multidisciplinary team at LLNL.

The position offers a hybrid work arrangement and requires U.S. citizenship, a relevant degree, and experience with radiation transport methods and computational

Qualifications

• U.S. citizenship with ability to obtain DOE Q-level clearance.
• Bachelor’s degree in Nuclear Engineering, Physics, or closely related discipline.
• Broad experience with radiation transport methods (MCNP, SCALE, GEANT, COG, Serpent, OpenMC).
• Computational physics background with programming in Python, Fortran, C++ or similar.
• Strong verbal and written communication for technical reports and presentations.
• Ability to work independently and in multidisciplinary teams.

Responsibilities

• Collaborate on design, modeling, and analysis of critical and subcritical experiments.
• Evaluate experimental benchmarks for ICSBEP.
• Develop radiation measurement instrumentation and measure radiation fields.
• Design and oversee fabrication of equipment as needed.
• Develop experimental procedures and guide reviews.
• Qualify as Nuclear Criticality Safety Engineer and perform safety evaluations.
• Publish and present results at conferences and journals.

Skills

DOE Q clearance

Radiation transport

Programming languages: Python, Fortran

Communication skills

Team collaboration

Analytical ability

Education

Bachelor's Degree in Nuclear Engineering/Physics

Masters/Doctorate preferred

Tools

MCNP

SCALE

GEANT

COG

Serpent

OpenMC

Job description

Company Description

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.

Job Description

We have an opening for a Nuclear Criticality Safety Research Staff Member in the Nuclear Criticality Safety Division within the Environment, Safety, and Health Directorate. We are seeking creative and flexible individuals who meet the scientific requirements and whose skills are aligned with the research mission of the national Nuclear Criticality Safety Program.This position requires interaction with professional colleagues inside and outside of the laboratory.

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 is eligible for a hybrid work environment combining on-site presence and the ability to work some days from home.

You will

• Collaborate in the moderately complex to complex design, modeling, and analysis of laboratory critical and subcritical experiments. Evaluate experimental benchmarks for the International Criticality Safety Benchmark Evaluation Project (ICSBEP).
• Collaborate in the development of radiation measurement instrumentation and measurement of radiation fields.
• Design and oversee fabrication of equipment as required.
• Develop experimental procedures as required and guide them through safety and management reviews.
• Qualify as a Nuclear Criticality Safety Engineer and assist in performing criticality safety evaluations of laboratory work.
• Publish research results in peer-reviewed scientific or technical journals and present results at external conferences, seminars, and/or technical meetings.
• Perform other duties as assigned.

Additional job responsibilities at the SES.3 level

• Function as a Principal Investigator for complex critical and subcritical experiments, leading the design, execution, and benchmarking phases of the project.
• Develop proposals for novel projects from existing and new sponsors.

Qualifications

• 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 equivalent combination of education and prior relevant experience.
• Broad experience with radiation transport methods, such as MCNP, SCALE, GEANT, COG, Serpent, OpenMC etc.
• Comprehensive experience in computational physics and working knowledge of one or more programming languages (Python, FORTRAN, C++, etc).
• Demonstrated proficient verbal and written communication skills necessary to author technical and scientific reports, proposals, publications and deliver scientific presentations.
• Ability to work under limited direction as well as in multidisciplinary research teams.
• Ability to provide moderately complex to complex analyses and develop unique technical solutions.

Additional qualifications at the SES.3 level

• Significant experience conducting and analyzing complex experiments involving nuclear material.
• Experience as an ICSBEP user, evaluator, or reviewer.

Qualifications We Desire

• Masters or Doctorate in Nuclear Engineering, Physics, or closely related discipline.
• Active DOE "Q" clearance.

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

$146,340- $185,544Annually at the SES.2 Level

$175,530- $222,564 Annually at the SES.3 Level

This is the lowest to highest salary range in good faith 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.

Additional Information

#LI-Hybrid

Position Information

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

Why Lawrence Livermore National Laboratory?

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

Security Clearance

This position requires a Department of Energy (DOE) Q-level clearance.If you are selected, wewill initiate a Federal background investigation to determine if youmeet 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 useand/or possession ofmobile devices in Limited Areas. Depending on your job duties, you may be required to work in a Limited Area whereyou are not permitted to have a personal and/or laboratory mobile devicein your possession. This includes, but not limited to cell phones, tablets, fitness devices, wireless headphones, and other Bluetooth/wireless enabled devices.

Ifyou useamedical device, whichpairs with a mobile device,you must still follow the rules concerningthe mobile device in individual sections within Limited Areas. Sensitive Compartmented Information Facilities requireseparate 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.

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.

CaliforniaPrivacy Notice

The California Consumer Privacy Act (CCPA) grants privacy rights to all California residents. The law also entitlesjob applicants, employees, and non-employee workers to be notified of what personal information LLNL collects and for what purpose. The Employee Privacy Notice can be accessed here.