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X Theoretical Design

A national resource for all aspects of nuclear weapons physics and design

Using state-of-the-art scientific theoretical, numerical, and experimental tools and methods to understand nuclear weapon design, performance, safety and surety, outputs and effects

We are a highly professional organization that prioritizes learning, values scholarship, and challenges assumptions. We develop new solutions through vigorous, respectful, and enthusiastic scientific discourse.

Download our Providing Solutions to the Toughest National Security Challenges brochure (PDF).

  • Integrated Design and Assessment (XTD-IDA)

    Enhances the understanding of thermonuclear physics.

    • Nuclear Threat Assessment (XTD-NTA)

      Provides expertise in nuclear weapon design physics to understand, characterize, and defeat foreign weapons and improvised devices.

      • Primary Physics (XTD-PRI)

        Designs nuclear weapon primaries and assesses their performance and reliability.

        • Safety and Surety (XTD-SS)

          Assesses the safety and surety of nuclear weapons and provides solutions to global-security and conventional-munitions challenges.

          • Radiation Transport Applications Group (XTD-RTA)

            Provides radiation transport modeling and simulation capabilities in support of the laboratory’s missions.

            XTD Programs

            ACQ Advanced Certification

            Advanced Certification and Qualification (ACQ) focuses on developing the ability to certify a responsive stockpile, including the ability to certify non-legacy systems, as well as supporting the qualification of new technologies for planned LEPs and new designs.

            C1 Primary Assessment Technologies

            The Primary Assessment Technologies (PAT) program develops and validates science-based models to better predict the performance of nuclear weapon primaries.

            C4 Secondary Assessment Technologies

            Secondary Assessment Technologies (SAT/C4) is focused on developing an improved understanding and capability to calculate key aspects of secondary performance.

            CNI Foreign Nuclear Weapon Assessment

            The Capabilities for Nuclear Intelligence (CNI) program develops expertise and resources that support nuclear intelligence assessments and ensure the resilience of the U.S. nuclear deterrent.