Management Team

Bradley Wallin

Principal Associate Director

Bradley Wallin

Dr. Wallin is the Program Director for Weapon Physics and Design (WPD) within LLNL’s Weapons and Complex Integration (WCI) Directorate. Dr. Wallin’s portfolio 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. This encompasses weapon science research and development including focused testing, integral hydrodynamic and subcritical experiments, high energy density experiments at the National Ignition Facility, and modeling and simulation using NNSA’s high performance computing capabilities. In addition, WPD manages efforts to accelerate manufacturing through new technologies and close partnerships with production agencies. Dr. Wallin has been in this role since 2019. Prior to leading WPD, Dr. Wallin was the Program Manager for the Nuclear Threat Reduction Program within LLNL’s Global Security Directorate from 2014-2019.

Dr. Wallin joined LLNL in 1997, where he worked in technical areas including computational physics and weapons design and provided technical leadership of dynamic material property experiments. Dr. Wallin holds a Doctorate in Physics from University of Illinois.


Des Pilkington

Deputy Principal Associate Director

Profile pic of D. 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.
 


Ivan Otero

Acting Program Director, Weapon Physics and Design

Ivan Otero

Ivan Otero is the acting program director for Weapon Physics and Design (WPD) Program, whose mission is to develop and apply validated, science-based capabilities to assess the performance and safety of the current and future U.S. nuclear stockpile, and to innovate technical solutions to anticipated national security problems. Otero is also the Deputy Program Director for Stockpile Design and Hydrodynamic Experiments (SDHE) in the Weapon Physics and Design program. One of his main roles is to lead the physics efforts to ensure the safety, security, and reliability of the US nuclear stockpile. In addition, he manages the execution of hydrodynamic experiments. These experiments, including subcritical experiments, underpin the physics designs and their certification. >Otero has 30 years of experience in the nuclear weapon design field. He has experience in secondary and primary design, as well as code development. His past roles at the Laboratory include: Associate Program Director for Stockpile Assessments, and Associate Program Director for Secondary Enabling Technologies.
 


Christopher Clouse

Program Director, Weapon Simulation and Computing

Christopher 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.


Derek Wapman

Program Director, Weapon Technologies and Engineering

Derek Wapman

Derek Wapman is the program director for WCI's Weapon Technologies and Engineering (WTE) Program, which supports activities in stockpile weapon monitoring and weapon life extension studies. The program also conducts component fabrication development projects to maintain effectiveness of the aging stockpile and to improve safety and security. The core of the WTE Program is the Defense Technologies Engineering Division (DTED) in the Engineering Directorate, which performs design studies of nuclear warheads to ensure the readiness to implement a weapon development process is maintained. It also develops sophisticated engineering software such as DYNA, NIKE, and PARADYN and performs leading-edge modeling and analysis of complex engineering problems in solid mechanics and heat transfer.
 


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.