Helping NNSA Managers Chart the Future Stockpile
SUCCESSIVE administrations have made clear that the future nuclear stockpile must be reliable, secure, and safe in the long term without the need for nuclear testing. The nation is committed to achieving a credible deterrent with the lowest possible number of nuclear weapons. Through the Moscow Treaty, the U.S. has already significantly reduced the number of deployed nuclear weapons.
As part of the effort to implement this vision, a number of high-level committees and task forces have taken a hard look at the nation’s nuclear weapons complex, the current nuclear stockpile, and strategies of deterrence. One of the most influential reviews, the 2001 Nuclear Posture Review (NPR), called for a redefinition of the strategic triad. Created during the Cold War, the long-standing strategic triad consists of intercontinental ballistic missiles, submarine-launched ballistic missiles, and bombers. In rethinking the needs of the nation’s nuclear forces in an era far removed from the Cold War, the NPR panel recommended a transition to a new triad of nonnuclear and nuclear capabilities.
One leg of the proposed triad is a responsive infrastructure, part of which would be a responsive nuclear enterprise. This element would increase the capability of the National Nuclear Security Administration (NNSA) to respond quickly to unanticipated events such as the discovery of a technical problem in stockpile warheads or the rise of a new geopolitical threat.
The current NNSA nuclear enterprise is receiving heightened scrutiny from Congress to ensure the continued reliability and safety of the nation’s nuclear weapons in a cost-effective manner. However, the enterprise—three laboratories, six plants, and the Nevada Test Site—is characterized by large and aging facilities and is faced with the need to support legacy warhead designs well beyond their originally projected lifetimes. Current estimates show that operating the NNSA’s Life Extension Program to maintain old warheads at the numbers and rate currently planned is likely to exceed anticipated federal funding.
Clearly, to reduce the stockpile and transition to a new strategic triad, the U.S. must transform the current nuclear enterprise to make it more responsive. Otherwise, the nation must continue keeping many warheads in reserve to guard against surprises.
Transforming the enterprise while meeting legacy stockpile obligations is difficult without sophisticated models to aid the planning process. Within NNSA, the need for a modeling tool to test future enterprise strategies had been under discussion for some time. Our vision at Livermore was to develop a tool that would accurately represent the flow of activities within the enterprise by incorporating accurate information such as financial, production, and stockpile data. In this way, NNSA managers could see more clearly how policy decisions might affect the enterprise. They could then optimize the transition from the present infrastructure to a more responsive one while maintaining important stockpile commitments.
As described in the article Modeling the Future, physicist Cliff Shang led a small team to build such a model. The team combined differential equations with an enormous database of information to model in extreme detail how the NNSA enterprise functions. We have been rigorously verifying and validating the new model to ensure it accurately reflects the workings of the enterprise. In this way, the task parallels our testing of new Advanced Simulation and Computing Program codes for NNSA supercomputers, which model highly nonlinear phenomena such as nuclear weapon performance. In a similar manner, the NNSA enterprise is a highly nonlinear system because of its complicated, interdependent activities.
Our hope is that this model will help not only NNSA managers but also individual NNSA sites in their efforts to meet the goal of a smaller, more responsive enterprise that can support a properly sized stockpile with reliable, safe, and secure nuclear weapons. In a time of constrained budgets, we want to provide NNSA managers with the best tools to more quantitatively inform the decision-making process as they, working with NNSA laboratories and plants, chart a path for transforming the enterprise into the future. I believe this is one of them.