Weapons Engineer Intern Jobs in California (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.

Positions will close to applicants on August 28, 2026. Computing mentors will have until September 4, 2026 to make their Fall selections.

We have multiple openings for our Computing Fall Undergraduate Internship Program taking place from September 1, 2026 through December 18, 2026. These positions are for undergraduate students who will be given the opportunity to engage in practical research to further their educational goals. Selected interns will play a key role in providing technical and/or research support to projects in areas such as computational science, cyber defense, computer science, numerical methods, mathematics, and other related STEM disciplines.

Depending on your assignment, this position may offer a hybrid schedule, blending in-person and virtual presence. You may have the flexibility to work from home one or more days per week.

You will 

• Provide technical and/or research support to projects in the areas of computational science, cyber defense, computer science, numerical methods, mathematics, and other related STEM disciplines, working with scientists, engineers, and technical staff members.
• Participate in research in assigned area under close supervision.
• Gather and analyze data and information in support of scientific research.
• Participate in research planning and evaluation discussions.
• Attend relevant seminars (at least one per week).
• Present work through presentations and/or poster sessions.
• Perform other duties as assigned.

• Must be eligible to access the Laboratory in compliance with Section 3112 of the National Defense Authorization Act (NDAA). See Additional Information section below for details.
• Must be a continuing college or university student in good standing at an accredited institution pursuing an undergraduate degree in Computer Science, Mathematics, Data Science, Machine Learning, Cybersecurity, or other related STEM fields. If you are starting a graduate degree program in Winter/Spring 2027, you must apply for the Computing Scholar Graduate position (Posting code: REF8511P).
• Proven ability to adapt and thrive in challenging situations, demonstrating resilience and problem-solving skills to achieve goals while overcoming setbacks.
• Ability to apply basic computational science and/or mathematical principles to solve technical problems.
• Demonstrated effective communication skills.
• Ability to present and communicate concepts and ideas.
• Experience working with personal computers and familiarity with Word, Excel and PowerPoint.
• Ability to work in a team environment.
• Age 18 or older at the start of the internship.
• Must have GPA of 3.0 or higher.

Pay Range

$23.26 - $31.62 Hourly for the 705.1 level
$28.77 Hourly for the 714.0 level

All your information will be kept confidential according to EEO guidelines.

Why Lawrence Livermore National Laboratory?

• Included in 2026 Best Places to Work by Glassdoor!
• Holiday Pay
• Sick leave accrual
• Individual 401(k) contributions
• Our values - visit https://www.llnl.gov/inclusion/our-values 

Security Clearance

None required.  However, if your assignment is longer than 179 days cumulatively within a calendar year, you must go through the Personal Identity Verification process.  This process includes completing an online background investigation form and receiving approval of the background check.  

National Defense Authorization Act (NDAA)

The 2025 National Defense Authorization Act (NDAA), Section 3112, generally prohibits citizens of China, Russia, Iran and North Korea without dual US citizenship or legal permanent residence from accessing specific non-public areas of national security or nuclear weapons facilities.  The restrictions of NDAA Section 3112 apply to this position.  To be qualified for this position, Candidates must be eligible to access the Laboratory in compliance with Section 3112.

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.

How to identify fake job advertisements

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. 

California Privacy Notice

The California Consumer Privacy Act (CCPA) grants privacy rights to all California residents. The law also entitles job 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.