Program Plan Science

vi, 46 pages. Illustrations (many in color). Acronyms and Abbreviations. The Office of Research and Development oversees the Science Program that is responsible for advancing the science that is important to Stockpile Stewardship. The Science Program is comprised of seven focus areas, some with associated facilities: Advanced Certifications and Assessment Methodologies (Underground Test data archive and analysis); Implosion Hydrodynamics; High Energy Density Physics; Materials and Nuclear Physics; Advanced Experimental Technologies Development; Capabilities for Nuclear Security; and Stewardship Science Academic Program. Stockpile stewardship refers to the United States program of reliability testing and maintenance of its nuclear weapons without the use of nuclear testing. Because no new nuclear weapons have been developed by the United States since 1992, even its youngest weapons are at least 25 years old (as of 2018). Aging weapons can fail or act unpredictably in a number of ways: the high explosives that condense their fissile material can chemically degrade, their electronic components can suffer from decay, and the isotopes used by thermonuclear weapons may be chemically unstable as well. The task of its stockpile maintenance resting on the use of simulations (using non-nuclear explosives tests and supercomputers, among other methods) and applications of scientific knowledge about physics and chemistry to the specific problems of weapons aging. It also involves finding other methods to increase the lifespan of existing warheads and maintain a confident nuclear deterrent. Draft--This appears to be the near final draft.