Senior Mechanical Engineer - Active Clearance Required

Lawrence Livermore National Laboratory; Livermore (CA); Hybrid; USD 211,000 - 267,000; Full time

Job summary

Lawrence Livermore National Laboratory in Livermore, CA is seeking a Senior Mechanical Engineer to participate in new and ongoing projects within the Initiation Systems Group. The role emphasizes mechanical and electromechanical design, prototyping, and testing in support of nuclear stockpile evaluation and maintenance.

You will interface with national labs, NNSA, and DoD, coordinate interfaces, and lead teams while contributing to safety documentation and design reviews.

Qualifications

• Active DOE Q clearance or Top Secret clearance is required at hire.
• Bachelor's degree in Mechanical Engineering or equivalent.
• Advanced knowledge of mechanical design and hardware analysis.
• Experience with prototype development and testing.
• Ability to lead multiple projects on schedule and budget.
• Strong communication and mentoring skills.

Responsibilities

• Provide technical expertise in mechanical and electromechanical design.
• Conduct structural, thermal, hydraulic, or dynamics modeling.
• Produce advanced conceptual and detailed designs for projects.
• Prepare health and safety documentation aligned with ISM.
• Coordinate interfaces with internal and external teams.
• Lead multidisciplinary project teams and provide direction.

Skills

Advanced communication

Leadership

Project management

Mentoring

Problem solving

Education

Bachelor's degree in Mechanical Engineering

Master's degree in Mechanical Engineering

PhD in Mechanical Engineering

Job description

Senior Mechanical Engineer - Active Clearance Required

Mid-Senior Level | Full-time
Engineering | Livermore, CA | 09/02/2026
Reference #: REF8803K
Job Code: SES.3 Science & Engineering MTS 3 / SES.4 Science & Engineering MTS 4
Organization: Engineering
Position Type: Career Indefinite
Security Clearance: Active DOE Q clearance (or active Top Secret clearance)
Drug Test: Required for external applicant(s) selected for this position (includes testing for use of marijuana)
Medical Exam: A job-related pre-placement medical examination may be required

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 Senior Mechanical Engineer to participate in new and ongoing projects within our Initiation Systems Group (ISG). The Initiation System Group provides nuclear weapon engineering design expertise; integration within systems engineering; experimental device design; shock & vibration and thermal testing; fabrication and assembly; and assessment of nuclear stockpile components for evaluation and maintenance of the enduring and future nuclear weapon stockpile with most of your focus on the ISG products. You will interface with colleagues at other National Laboratories and Production Agencies, National Nuclear Security Administration (NNSA), and Department of Defense (DoD) and their contractors. These positions are in the Defense Technologies Engineering Division (DTED), within the Engineering Directorate. DTED provides support to Strategic Deterrence Programs.

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.

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.

You will

• Provide technical expertise in mechanical and electromechanical design.
• Conduct research in structural, thermal, hydraulic, or dynamics modeling of mechanical systems.
• Produce advanced conceptual and detail designs in support of on-going projects.
• Prepare supporting health and safety documentation that is aligned with the Integrated Safety Management (ISM) requirement and participate in design and Management Prestart Reviews.
• Coordinate project interfaces and deployment interfacing with other organizations internal and external to the Laboratory.
• Lead and/or provide guidance and technical direction to multidisciplinary project teams in a growing, dynamic environment.
• Perform other duties as assigned.

Additional job responsibilities, at the SES.4 level

• Set broad project vision and strategy and influence technical direction for self and others.
• Provide expert capability in highly complex mechanical design and analysis.

Qualifications

• This position requires an active Department of Energy (DOE) Q-level clearance or active Top Secret clearance issued by another U.S. government agency at the time of hire.
• Bachelor's degree in Mechanical Engineering or a related field, or the equivalent combination of education and related experience.
• Advanced knowledge of mechanical design.
• Significant experience in prototype development and testing, as well as hardware design and analysis.
• Ability to devise solutions for unique and complex problems.
• Ability and flexibility to reprioritize and change programmatic direction depending on emergent requests.
• Significant experience in managing, overseeing, and delivering multiple projects on budget and schedule.
• Ability to lead, manage, and mentor junior team members.
• Advanced communication skills with proven ability to present concepts and ideas in a clear and coherent manner, both verbal and written for presentation and interaction with other technical staff members.

Additional qualifications at the SES.4 level

• Expertise in highly complex mechanical design and analysis and significant experience in project planning and highly complex technical leadership.
• Significant experience developing and implementing creative solutions to a diverse range of highly complex problems and leading corrective actions where necessary.
• Expert communication, facilitation, and collaboration skills necessary to present, explain, and advise senior management and/or external sponsors and proven record of team building and conflict resolution.

Qualifications We Desire

• Master's degree or PhD in Mechanical Engineering or a related field.
• Advanced knowledge of systems engineering principles and practices and their application.
• Production experience specifically in aerospace, gas & oil, or medical industries.
• Certified in Six Sigma Green Belt

Pay Range

$175,530 - $267,060 Annually

$175,530 - $222,564 Annually for SES.3 Level
$210,630 - $267,060 Annually for SES.4 Level

This is the lowest to highest salary in good faith we would pay for this role at the time of this posting. Pay will not be below any applicable local minimum wage. 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!
• Flexible schedules (*depending on project needs)

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 deviceyou 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.

Pre-Placement Medical Exam

A job related pre-placement medical examination may be required.

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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