The QMU Methodology Is Highly Promising but Still in the Early Stages of Development

NNSA has endorsed the use of a new common methodology, known as the  quantification of margins and uncertainties, or QMU, for assessing and  certifying the safety and reliability of the nuclear stockpile. To date, NNSA has commissioned two technical  reviews of the implementation of QMU at the weapons laboratories. While  strongly supporting QMU, the reviews found that the development and  implementation of QMU was still in its early stages. The reviews  recommended that NNSA take steps to further define the technical details  supporting the implementation of QMU and integrate the activities of the  three weapons laboratories in implementing QMU. Starting in 2001, LLNL and LANL began developing what is intended to be a  common methodology for assessing and certifying the performance and  safety of nuclear weapons in the absence of nuclear testing. The process envisaged in the white paper focuses on creating a “watch list”  of factors that, in the judgment of nuclear weapons experts, are the most  critical to the operation and performance of a nuclear weapon. Specifically, the QMU methodology seeks to  quantify (1) how close each critical factor is to the point at which it would  fail to perform as designed (i.e., the performance margin or the margin to  failure) and (2) the uncertainty in calculating the margin. In a broad range of key planning and management documents that have  followed the issuance of the white paper, NNSA and the weapons  laboratories have endorsed the use of the QMU methodology as the  principal tool for assessing and certifying the safety and reliability of the  nuclear stockpile in the absence of nuclear testing. The Development and Implementation of QMU Is at an Early Stage and Important Differences Exist Among the Weapons Laboratories in their Application of QMU

According to NNSA and laboratory officials, the weapons laboratories have  made progress in applying the principles of QMU to the certification of life  extension programs and to the annual stockpile assessment process. For example, LLNL and  LANL officials told us that, at a detailed level, the two laboratories are  pursuing different approaches to calculating and combining uncertainties. According to NNSA policies,  campaign managers at NNSA headquarters are responsible for developing  campaign plans and high-level milestones, overseeing the execution of  these plans, and providing input to the evaluation of the performance of the  weapons laboratories. However, NNSA’s management of these processes is  deficient in four key areas. Second, NNSA has not  developed a clear, consistent set of milestones to guide the development  and implementation of QMU. Third, NNSA has not established formal  requirements for conducting annual, technical reviews of the  implementation of QMU or for certifying the completion of QMU-related  milestones. Finally, NNSA has not established adequate performance  measures to determine the progress of the laboratories in developing and  implementing QMU. To ensure that NNSA can more effectively manage the development and  implementation of QMU, we recommend that the Administrator of NNSA  take the following three actions:  Develop an integrated plan for implementing QMU that contains (1)  clear, consistent, and realistic milestones for the development and  implementation of QMU across the weapons complex and (2) formal  requirements for certifying the completion of these milestones.
Why GAO Did This Study

In 1992, the United States began a unilateral moratorium on the testing of nuclear weapons. To compensate for the lack of testing, the Department of Energy's National Nuclear Security Administration (NNSA) developed the Stockpile Stewardship Program to assess and certify the safety and reliability of the nation's nuclear stockpile without nuclear testing. In 2001, NNSA's weapons laboratories began developing what is intended to be a common framework for a new methodology for assessing and certifying the safety and reliability of the nuclear stockpile without nuclear testing. GAO was asked to evaluate (1) the new methodology NNSA is developing and (2) NNSA's management of the implementation of this new methodology.

What GAO Found

NNSA has endorsed the use of the "quantification of margins and uncertainties" (QMU) methodology as its principal method for assessing and certifying the safety and reliability of the nuclear stockpile. Starting in 2001, Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL) officials began developing QMU, which focuses on creating a common "watch list" of factors that are the most critical to the operation and performance of a nuclear weapon. QMU seeks to quantify (1) how close each critical factor is to the point at which it would fail to perform as designed (i.e., the margin to failure) and (2) the uncertainty that exists in calculating the margin, in order to ensure that the margin is sufficiently larger than the uncertainty. According to NNSA and laboratory officials, they intend to use their calculations of margins and uncertainties to more effectively target their resources, as well as to certify any redesigned weapons envisioned by the Reliable Replacement Warhead program. According to NNSA and weapons laboratory officials, they have made progress in applying the principles of QMU to the assessment and certification of nuclear warheads in the stockpile. NNSA has commissioned two technical reviews of the implementation of QMU. While strongly supporting QMU, the reviews found that the development and implementation of QMU was still in its early stages and recommended that NNSA further define the technical details supporting the implementation of QMU and integrate the activities of the three weapons laboratories in implementing QMU. GAO also found important differences in the understanding and application of QMU among the weapons laboratories. For example, while LLNL and LANL both agree on the fundamental tenets of QMU at a high level, they are pursuing different approaches to calculating and combining uncertainties. NNSA uses a planning structure that it calls "campaigns" to organize and fund its scientific research. According to NNSA policies, campaign managers at NNSA headquarters are responsible for developing plans and high-level milestones, overseeing the execution of these plans, and providing input to the evaluation of the performance of the weapons laboratories. However, NNSA's management of these processes is deficient in four key areas. First, NNSA's existing plans do not adequately integrate the scientific research currently conducted across the weapon complex to support the development and implementation of QMU. Second, NNSA has not developed a clear, consistent set of milestones to guide the development and implementation of QMU. Third, NNSA has not established formal requirements for conducting annual, technical reviews of the implementation of QMU at the three laboratories or for certifying the completion of QMU-related milestones. Finally, NNSA has not established adequate performance measures to determine the progress of the three laboratories in developing and implementing QMU.