WCI Management Team

Bradley Wallin

Principal Associate Director

Brad Wallin

Brad Wallin is the Principal Associate Director for Weapons and Complex Integration (WCI) at Lawrence Livermore National Laboratory (LLNL). He leads the Laboratory’s nuclear weapons program in its responsibilities to ensure the safety, security, and effectiveness of the Nation’s nuclear deterrent and to support the transformation of the stockpile and the nuclear weapons enterprise for the future. He is also responsible for stewarding the broad range of science, technology, and engineering capabilities and infrastructure that underpin the Stockpile Stewardship Program (SSP) and lay the foundations for the long-term health and vitality of the Laboratory.   

Wallin has more than 24 years of experience in nuclear security, including as Program Director for Weapon Physics and Design, Program Manager for Nuclear Threat Reduction, and as a technical advisor to the Office of Defense Science at the National Nuclear Security Administration. His technical career spans the many disciplines of weapon physics, including design, code development, and management of nuclear and high-energy-density facilities and experiments. 

Des Pilkington

Principal Deputy Principal Associate Director

Des Pilkington

Des Pilkington brings almost 40 years of experience in the nuclear weapon design field, drawing on experience in primary and secondary design, as well as code development and experimentation. His past roles within WCI include: Weapon Physics and Design Program director, Design Physics Division leader, AX Program director, advanced physics project leader, computational physics deputy associate program leader, and physicist. He also served on assignment to the Atomic Weapons Establishment (AWE) in England, where he served as head of the High-Performance Computing (HPC) Department and was responsible for their HPC strategy, development, and delivery. Pilkington received his BSc in mathematics and his MSc in astrophysics, both from London University and served over 20 years in various code development and management roles at AWE before joining LLNL in 2001.

Philip W. Pellette

Deputy for Operations

Phil Pellette

Phil Pellette is responsible for the full suite of WCI operational activities on the main site and Site 300, including managing and improving the infrastructure and capability of WCI facilities in support of LLNL's mission, worker and public safety, and the expansion of programmatic activities. He also oversees the development and implementation of plans, processes, and procedures to provide assurance that all directorate activities are performed in compliance with LLNL policies, in addition to laws and regulations. Pellette brings more than 30 years of relevant experience to the role, with a particular emphasis on nuclear and waste facility operations, including those in the commercial power industry and at Los Alamos National Laboratory. He received a B.S. degree in engineering from West Point, an M.E. degree in hazardous waste engineering from the University of New Mexico, and an M.S. degree in mechanical engineering from the University of California, Davis.

Benjamin Grover

Deputy for Program Enablement

Benjamin Grover

With almost 20 years of experience leading highly technical teams and organizations through changes, Benjamin Grover brings with him not only exceptional leadership skills but a deep familiarity with the U.S. nuclear weapons program, high-performance computing, scientific software development, business development, project management, and strategic planning. His leadership provides the focal point for all aspects of strategic staffing, working in partnership with stakeholders to ensure a coordinated approach to recruiting, hiring, and development, while ensuring the successful long-term delivery of WCI’s programs and projects. Prior to his increasing leadership roles in WCI, he served as a division leader within LLNL's Computing Directorate and a detailee at the Department of Energy, forging a new program to bring high-performance computing software to industry. Grover received a B.S. and M.S. in civil engineering from Brigham Young University and is a certified project management professional.

Ashley Bahney

Chief of Staff

Ashley Bahney

As the WCI Chief of Staff, Ashley Bahney is responsible for development of organizational strategies and priorities within WCI Programs. Bahney brings expertise in strategy development and program management from her work at the State Department, Department of Defense, LLNL, and working across the NNSA tri-lab community. She has extensive knowledge of the nuclear security enterprise and strong experience with strategic communications. Bahney has an M.A. in international affairs from the University of California, San Diego, a B.A. in international relations from the University of California, Davis, and a certificate in national security affairs from Texas A&M University.

Mark Herrmann

Program Director, Weapon Physics and Design

Mark Herrmann

Dr. Herrmann is the Program Director for the Weapon Physics and Design (WPD) Program within LLNL’s Weapons and Complex Integration (WCI) Directorate. In this role, Dr. Herrmann leads LLNL’s efforts to strengthen our nation’s nuclear deterrent by advancing our understanding of nuclear weapons physics and design. This includes the physics design, assessment, and certification efforts for the enduring LLNL systems (W80, B83, W87), the W80-4 Life Extension Program, and the W87-1 Modification program. He also leads weapon science research and development, including focused experiments, integral hydrodynamic and subcritical experiments, high-energy-density (HED) experiments at the National Ignition Facility (NIF), and modeling and simulation using NNSA’s high performance computing capabilities. Dr. Herrmann has been in this role since January 2022.

Prior to his current role, Dr. Herrmann was Deputy Program Director for Fundamental Weapons Physics, where he led LLNL’s efforts in the areas of HED science, focused materials science, and inertial confinement fusion that help enable WPD. Previously, Dr. Herrmann was the Director of NIF, the world’s most energetic laser, where he led and managed the NIF and 650-person team that operates, maintains, and develops its new capabilities. Dr. Herrmann returned to LLNL to become the NIF Director in October 2014 after nine years at Sandia National Laboratories, where he led research on use of the Z facility to study HED matter. Dr. Herrmann was awarded a Presidential Early Career Award for Scientists and Engineers and the American Physical Society Award for Outstanding Doctoral Dissertation in Plasma Physics, and he is a fellow of the American Physical Society.

Christopher Clouse

Program Director, Weapon Simulation and Computing

Chris Clouse

Chris Clouse is the acting program director for WCI's Weapon Simulation and Computing (WSC) Program, in which he has responsibility overseeing the development and delivery of simulation capabilities to ensure the safety, security, and effectiveness of the U.S. nuclear stockpile. This includes procuring, siting, and managing computing platforms and their infrastructure; management of the Livermore Computing Center; and development of simulation tools in support of national security missions. Before joining the Laboratory in 1992, he spent nine years as an Air Force officer, the last three at the Lab as a military research associate. Prior to his current position, he served as Associate Program Director for Computational Physics in WSC, managing the development of simulation tools including about a dozen major code projects. Clouse has a Ph.D. in nuclear engineering from the University of New Mexico, an M.S. from the Air Force Institute of Technology, and a B.S. in Physics from the University of Notre Dame.

John Miller

Program Director, Weapon Technologies and Engineering

John Miller

John Miller is the program director for WCI's Weapon Technologies and Engineering (WTE) Program, which is committed to providing engineering and scientific excellence in support stockpile stewardship and other critical national security missions.

Miller has been a part of WTE for almost 20 years supporting various weapon system programs including roles on the W80-3 LEP, the Reliable Replacement Warhead, the W78/88 LEP, and the W87-1 Modernization Program. Miller has also served as the Reentry Systems Group Leader and System Manager for the W87-0. From 2018 until 2021 Miller served as the WTE Associate Program Director for Stockpile Systems. Miller received a S.B. from MIT and a M.S. from the University of California, Davis, both in mechanical engineering.

Cliff Shang

Program Director, Weapons Infrastructure

Cliff Shang

Cliff Shang is the program director for WCI's Weapons Infrastructure (WI) Program, which enables nuclear weapons infrastructure-based capability sustainment and delivery; modernizes nuclear weapons program equipment; and performs nuclear weapon enterprise evaluation and planning. The WI Program directly supports LLNL’s execution of modernization programs, annual certification and assessment processes, and enduring stockpile sustainment. The WI Program serves as the principal point of contact for weapons infrastructure activities for capital planning and acquisition. The WI Program also manages NNSA's Safety, Infrastructure, and Operations (SIO) portfolio at LLNL for nuclear weapons capabilities.

Shang concurrently serves as Director for the Office of Laboratory Infrastructure where he leads an integrated organization responsible for the planning, sustainment, and modernization of LLNL's capital infrastructure base. Within this program area, Shang has received five Defense Program Awards of Excellence, two NNSA SIO (NA-50) Excellence Awards, and an Energy Secretary’s Achievement Award.