The U.S. Department of Energy's (DOE) National Nuclear Security Administration (NNSA) is responsible for the safety and reliability of the U.S. nuclear weapons stockpile, including production readiness required to maintain that stockpile. Since 1989, DOE has been without the capability to produce stockpile certified plutonium pits, which are an essential component of nuclear weapons. NNSA, the Department of Defense (DOD), and Congress have highlighted the lack of long-term pit production capability as a national security issue requiring timely resolution. While a small interim capacity is currently being established at the Los Alamos National Laboratory (LANL), classified analyses indicate projected capacity requirements (number of pits to be produced over a period of time), and agility (ability to rapidly change from production of one pit type to another, ability to simultaneously produce multiple pit types, or the flexibility to produce pits of a new design in a timely manner) necessary for long-term support of the stockpile will require a long-term pit production capability. In particular, identification of a systemic problem associated with an existing pit type, class of pits, or aging phenomenon cannot be adequately responded to today, nor could it be with the small capability being established at LANL (see Section S.2 for a more detailed discussion regarding the purpose and need for a Modern Pit Facility [MPF]).