Responsibility for U.S. nuclear weapons resides with both the Department of Defense (DOD) and the Department of Energy (DOE). DOD develops, deploys, and operates the missiles and aircraft that can deliver nuclear warheads. It also generates the military requirements for the warheads carried on those platforms. The National Nuclear Security Administration (NNSA), which is a semi-autonomous agency within the Department of Energy, oversees the research, development, test, and acquisition programs that produce, maintain, and sustain the warheads. Moreover, DOE is responsible for storing and securing the warheads that are not deployed with DOD delivery systems and for dismantling warheads that have been retired and removed from the stockpile. Congress authorizes funding for both DOD and NNSA nuclear weapons activities in the annual National Defense Authorization Act (NDAA). While Congress considers appropriations for DOD's nuclear weapons activities in the Defense Appropriations bill, it funds the NNSA budget through the Energy and Water Development Appropriations bill. This report focuses on the portion of the Energy and Water Development Appropriations Bill that funds NNSA's nuclear weapons activities. During World War II, when the United States first developed nuclear weapons, the Army managed the nuclear weapons program. In 1946, Congress passed the Atomic Energy Act of 1946 to establish the Atomic Energy Commission (AEC). The AEC was an independent civilian agency tasked with managing the U.S. nuclear weapons program. In the Energy Research and Development Act of 1974, Congress dissolved the AEC and created the Nuclear Regulatory Commission and the Energy Research and Development Administration (ERDA), which among other functions managed the nuclear weapons program. That program was moved again by the Department of Energy Organization Act of 1977, which dissolved ERDA and created DOE. Congress, in passing the National Defense Authorization Act for Fiscal Year 2000 ( P.L. 106-65 , Title XXXII), established the National Nuclear Security Administration. NNSA is a semi-autonomous agency operating within DOE. In addition to managing the nuclear weapons program, NNSA also manages the Defense Nuclear Nonproliferation and Naval Reactors programs. These reorganizations stem, in part, from long-standing concerns about the management of the nuclear weapons complex. Many reports and legislative provisions have been written over the past several decades to address this issue. Most recently, in the National Defense Authorization Act for Fiscal Year 2013 ( P.L. 112-239 ), Congress established the Congressional Advisory Panel on the Governance of the Nuclear Security Enterprise and directed the panel to make recommendations on "the most appropriate governance structure, mission, and management of the nuclear security enterprise." In its report to Congress, the panel stated The panel finds that the existing governance structures and many of the practices of the enterprise are inefficient and ineffective, thereby putting the entire enterprise at risk over the long term. These problems have not occurred overnight; they are the result of decades of neglect. This is in spite of the efforts of many capable and dedicated people who must nonetheless function within the confines of a dysfunctional system.… One unmistakable conclusion is that NNSA governance reform, at least as it has been implemented, has failed to provide the effective, mission-focused enterprise that Congress intended. The panel's recommendations included strengthening presidential guidance and oversight of the nuclear enterprise; establishing new congressional mechanisms for leadership and oversight of the enterprise; replacing NNSA with a new Office of Nuclear Security within DOE, renamed to the Department of Energy and Nuclear Security, with the Secretary responsible for the mission; and building a culture of performance, accountability, and credibility. NNSA, in its review of the report, supported many of the suggested changes in management and contracting within NNSA, but did not support the proposed changes in the name and structure of the organization or its leadership. Congress has also expressed concerns about cost growth and transparency in NNSA's programs. These concerns focus on both major construction projects and weapons refurbishment programs. Congress addressed these concerns in the Consolidated and Further Continuing Appropriations Act for 2015 ( P.L. 113-235 ). Section 304 required that NNSA's construction of high-hazard nuclear facilities have independent oversight by the Office of Independent Enterprise Assessments "to ensure the project is in compliance with nuclear safety requirements." Section 305 required an independent cost estimate for approving performance baseline and starting construction for projects with total cost over $100 million. Section 308 required the Secretary of Energy to provide an analysis of alternatives for each major warhead refurbishment program reaching the development engineering stage. The Senate reiterated its concerns in S.Rept. 114-54 , its report on H.R. 2028 , the Energy and Water Development and Related Agencies Appropriations Act, 2016. In this report, the committee expressed its concern "with the continued poor cost estimating by the Department, particularly within the NNSA," and directed the Secretary of Energy to "provide a report … that outlines the Department's plan for improving cost estimating for major projects and programs." At the end of the Cold War in 1991, the U.S. nuclear weapons complex consisted of 14 sites—3 laboratories, the nuclear weapons test site in Nevada, and a number of manufacturing plants for weapons materials and components. As the number of nuclear weapons in the U.S. arsenal declined and demand for new warheads and materials abated in the 1990s, the United States closed several facilities in the complex. The complex now consists of eight sites in seven states. These sites include three laboratories (Los Alamos National Laboratory, NM; Lawrence Livermore National Laboratory, CA; and Sandia National Laboratories, NM and CA); four production sites (Kansas City Plant, MO; Pantex Plant, TX; Savannah River Site, SC; and Y-12 National Security Complex, TN); and the Nevada National Security Site (formerly Nevada Test Site). NNSA manages and sets policy for the complex; contractors operate the eight sites. Despite the post-Cold War reductions in the complex, some in Congress have pressed for further changes, seeking additional reductions in personnel, greater efficiencies in production, a smaller footprint at each site, and increased security. Many Members have also supported calls for increased investments within the complex, both to replace aging facilities and improve operations and security. The Obama Administration requested increased funding for the nuclear weapons complex in each of its annual budgets. In an editorial published in late January 2010, Vice President Biden noted that U.S. nuclear laboratories and facilities had been "underfunded and undervalued" for more than a decade. He stated that the President's budget request for FY2011 would include "$7 billion for maintaining our nuclear-weapons stockpile and complex, and for related efforts," an amount that was $600 million more than Congress appropriated for FY2010. He also stated that the Administration would "boost funding for these important activities by more than $5 billion" over the next five years. While the passage of the Budget Control Act in late 2011 slowed the increases in NNSA budgets, as is evident in the figure below, the actual appropriations for NNSA's weapons activities have begun to exceed the expectations outlined in the 1251 Report in 2010. The Obama Administration further outlined its funding plans for the nuclear weapons enterprise in a report submitted to Congress in May 2010, and updated in November 2010, in support of the ratification of the New START Treaty. Congress had requested this report, known as the "1251 report" in the National Defense Authorization Act for Fiscal Year 2010 ( P.L. 111-84 ), Section 1251, and mandated that it outline a comprehensive plan to "(1) maintain delivery platforms [that is, bombers, missiles, and submarines that deliver nuclear weapons]; (2) sustain a safe, secure, and reliable U.S. nuclear weapons stockpile; and (3) modernize the nuclear weapons complex." In the November 2010 update of that document, the Administration projected weapons stockpile and infrastructure costs for FY2011-FY2020 at between $85.4 billion and $86.2 billion. As is shown on Figure 1 , above, funds appropriated for these programs fell below the projected levels early in the decade. However, the FY2017, FY2018, and FY2019 budget requests and projections for subsequent years now exceed the amount predicted in the 2010 report. The Trump Administration, in its budget for FY2018, requested an additional $1 billion for NNSA weapons activities over the level appropriated in FY2017. (NNSA's budget request showed an increase of $1.4 billion, but this compared FY2018 with FY2016 funding levels.) While the Administration had indicated in its "skinny budget" that this increase would support both deferred maintenance requirements among the NNSA weapons facilities and the warhead life extension programs in the directed stockpile area of the budget, funding for deferred maintenance in infrastructure and operations accounts remained essentially unchanged from the FY2017 appropriated levels. Most of the increases in the funding request for FY2018 divided between the life extension programs and research and development activities. Congress enacted a budget of $10.642 billion for weapons activities NNSA in FY2018, in the Consolidated Appropriations Act, 2018 ( P.L. 115-141 ). The Trump Administration's budget for FY2019 continued to fund increases in NNSA's weapons activities, requesting $11.02 billion, an increase of nearly $400 million over the funding enacted in FY2018. Congress enacted a budget of $11.1 billion for weapons activities in the Energy and Water, Legislative Branch, and Military Construction and Veterans Affairs Appropriations Act, 2019 ( P.L. 115-244 ). The United States conducted 1,030 nuclear weapons test explosions between 1945 and 1992. These were the primary means by which the United States both determined whether its nuclear weapons designs would work and confirmed that the weapons remained reliable and effective as they aged.