【英文】美国军力评估报告：美国核武器能力（27页）

英文研究报告 2021年11月09日 07:59 管理员

U.S. warheads must be safe, secure, efective, and reliable. The Department of Defense de- fifines reliability as “the probability that a weapon will perform in accordance with its design intent or military requirements.”27 Since the cessation of nuclear testing in 1992, reliability has been assessed and maintained through the NNSA’s Stockpile Stewardship Program, which consists of an intensive warhead surveillance program; non-nuclear experiments (i.e., experiments that do not produce a nuclear yield); sophisticated calculations using highperformance computing; and related annual assessments and evaluations. The reliability of nuclear warheads and delivery systems becomes even more important as the number and diversity of nuclear weapons in the stockpile decrease. Fewer types of nuclear weapons results in a smaller margin of error if all of one type are afected by a technical problem that might cause a weapon type or its delivery system to be decommissioned. Loss of diversity in the stockpile also increases the risk of “common-mode” failure that could afect multiple systems simultaneously, making the push for commonality with potential single points of failure in U.S. warheads worrisome.

America and its allies must have high confifidence that U.S. nuclear warheads will perform as expected. As warheads age, uncertainty about their ability to perform their mission as expected could increase and signifificantly complicate military planning. Despite creating impressive amounts of knowledge about nuclear weapons physics and materials chemistry, the United States could fifind itself surprised by unanticipated long-term efects on aging components that comprise a nuclear weapon. “The scientifific foundation of assessments of the nuclear performance of US weapons is eroding as a result of the moratorium on nuclear testing,” argue John Hopkins, nuclear physicist and a former leader of the Los Alamos National Laboratory’s nuclear weapons program, and David Sharp, former Laboratory Fellow and a guest scientist at Los Alamos National Laboratory.28 The United States currently has the world’s safest and most secure stockpile, but concerns about overseas storage sites, potential problems introduced by improper handling, or unanticipated efects of aging could compromise the integrity or reliability of U.S. warheads. The nuclear warheads themselves contain security measures that are designed to make it difcult, if not impossible, to detonate a weapon without proper authorization. Some U.S. warheads have modern safety features that provide additional protection against accidental detonation; others do not.