Congress funds NNSA’s modernization efforts through various activities and programs within the Weapons Activities appropriation that generally address four areas: (1) stockpile, (2) infrastructure, (3) ST&E capabilities, The four areas, which are described in and (4) other weapons activities.greater detail below, are interconnected. For example, research and experiments funded in the ST&E area contribute to the design and production of refurbished weapons, funded in the stockpile area. The infrastructure area offers critical support to both the stockpile and ST&E capabilities areas by providing a suitable environment for their various activities, such as producing weapons components and performing research and experimentation activities. The other weapons activities area offers support to the three other areas by, for example, providing for the security of nuclear weapons and nuclear material. In fiscal year 2015, the President requested $8.3 billion in total appropriations for Weapons Activities, and the Congress appropriated $8.2 billion. The stockpile area includes weapons refurbishments through LEPs and other major weapons alterations and modifications; surveillance efforts to evaluate the condition, safety, and reliability of stockpiled weapons; maintenance efforts to perform certain minor weapons alterations or to replace components that have limited lifetimes; and core activities to support these efforts, such as maintaining base capabilities to produce uranium and plutonium weapons components. Our analysis of NNSA’s data indicates that about 40 percent of the budget estimates for the stockpile area from 2015 to 2039 is for LEPs. The U.S. nuclear weapons stockpile is composed of seven different weapon types, including air- delivered bombs, ballistic missile warheads, and cruise missile warheads (see table 1). The infrastructure area involves NNSA-owned, leased, and permitted physical infrastructure and facilities supporting weapons activities. NNSA’s 2015 nuclear security budget materials include information on budget estimates for three major types of infrastructure activities: operating and maintaining the existing infrastructure, recapitalizing (improving) existing facilities, and constructing new facilities. Our analysis of NNSA’s budget materials indicates that about 57 percent of the budget estimates for infrastructure from 2015 to 2039 is for the operation, maintenance, and recapitalization of existing facilities and about 27 percent is for new facilities construction. The ST&E capabilities area is composed of five “campaigns,” which are technically challenging, multiyear, multifunctional efforts to develop and maintain critical science and engineering capabilities, including capabilities that enable the annual assessment of the safety and reliability of the stockpile, improve understanding of the physics and materials science associated with nuclear weapons, and support the development of code-based models that replace underground testing. Our analysis of NNSA’s data indicates that about 36 percent of the budget estimates for the ST&E capabilities area from 2015 to 2039 are for the Advanced Simulation and Computing Campaign. This campaign procures supercomputers; develops the computer code to simulate nuclear weapons; and develops simulations to analyze and predict these weapons’ performance, safety, and reliability and to certify their functionality. Other weapons activities include budget estimates associated with nuclear weapon security and transportation, as well as legacy contractor pensions, among other things. Our analysis of NNSA’s data indicates that about 44 percent of the budget estimates for the other weapons activities area from 2015 to 2039 are for nuclear weapon security. NNSA’s modernization efforts in the areas described above include those directed toward NNSA’s goal of stopping the growth of its deferred maintenance backlog in its facilities and infrastructure.maintenance can be avoided either by conducting scheduled Deferred maintenance activities, recapitalization activities, or demolition activities. Maintenance activities—including the replacement of parts, systems, or components—are needed to preserve or maintain a facility in an acceptable condition to safely operate. Regular maintenance throughout a facility’s service life can minimize deferred maintenance or prevent it from accumulating. NNSA’s budget materials contain two categories of maintenance budget estimates: direct-funded and indirect-funded. According to a NNSA official, estimates for direct-funded maintenance are included in the budget in two places: (1) the maintenance account specified in NNSA’s budget materials and (2) the program budgets for certain NNSA programs that are the major users of key scientific and production facilities, such as the Advanced Simulation and Computing Facility at Lawrence Livermore National Laboratory and the Tritium Extraction Facility at the Savannah River Site. Indirect-funded maintenance represents activities that are budgeted and paid for as part of a site’s overhead costs. According to NNSA officials, some sites, such as Lawrence Livermore National Laboratory, use indirect-funded maintenance as the primary way to budget and pay for maintenance. The 2015 budget materials estimate that NNSA will budget $1.6 billion for direct-funded maintenance over the next 5 years and $2.3 billion for indirect-funded maintenance over the next 5 years. NNSA identifies the total direct and indirect budget estimates planned for maintenance at each site and reports this information for the FYNSP in the congressional budget justification. NNSA is required by DOE to collect this information from its management and operating contractors through a DOE prescribed tool known as the Integrated Facilities and Infrastructure Crosscut Budget. NNSA can recapitalize facilities or their subsystems (e.g., roofing, ventilation systems, and electrical systems) when they wear out or become outdated (i.e., reach the end of their useful service life). For example, in 2016 NNSA plans to replace approximately 500 sprinkler heads, which are about 50 years old, in a building that manufactures nonnuclear components at its Y-12 National Security Complex in Tennessee. Similarly, in 2015, NNSA continues to upgrade a control tower’s electrical and mechanical components at its Sandia National Laboratories site in New Mexico to support nonnuclear testing activities for nuclear bombs. The 2015 budget materials estimate that $1.8 billion will be spent on recapitalization over the next 5 years and that $11.5 billion will be spent on such recapitalization over the next 25 years. According to officials, if NNSA determines that a facility is no longer needed for mission operations, the agency can demolish the facility. For example, NNSA recently demolished building 9744 at the Y-12 plant because the support structure was failing. Budget estimates for demolition are included as a subprogram in the recapitalization estimates; the 2015 budget materials contain 5-year budget estimates of $105 million and 25-year estimates of $230 million for demolition activities. The current process by which NNSA prioritizes infrastructure investment is based on data on a facility’s condition and importance to achieving programmatic goals. Contractors that manage and operate each site within the nuclear security enterprise are required by a DOE order to inspect all facilities on their site at least every 5 years and are to update DOE’s infrastructure database annually with information relating to the condition of the site’s facilities. This information includes estimating the amount of a facility’s deferred maintenance and its replacement plant value, which is the cost to replace the existing structure with a new structure of comparable size using current technology, codes, standards, and materials. According to DOE’s real property asset management order, a facility’s condition is determined based on the scale shown below in figure 1. NNSA categorizes each individual facility’s importance to accomplishing its mission based on designations defined by the Federal Real Property Council. The categories are as follows: Mission critical. Facilities and infrastructure that are used to perform activities—such as nuclear weapons production, research and development, and storage—to meet the highest-level programmatic goals, without which operations would be disrupted or placed at risk. According to NNSA data, 245 (or 4.0 percent) of the agency’s 6,085 facilities are designated as mission critical. Mission dependent, not critical. Facilities and infrastructure—such as waste management, nonnuclear storage, and machine shops—that play a supporting role in meeting programmatic goals. According to NNSA data, 2,063 (or 33.9 percent) of the agency’s 6,085 facilities are designated as mission dependent, not critical. Not mission dependent. Facilities and infrastructure—such as cafeterias and parking structures, that do not link directly to programmatic goals but support secondary missions or quality-of- workplace initiatives. According to NNSA data, 3,777 (or 62.1 percent) of the agency’s 6,085 facilities are designated as not mission dependent. NNSA’s 2015 budget estimates for modernization total $293.4 billion over 25 years, an increase of $17.6 billion (6.4 percent) from the $275.8 billion in estimates provided in 2014. These budget estimates are provided in four program areas: stockpile, infrastructure, ST&E, and other weapons activities. Some budget estimates for individual programs within these four areas changed more significantly from 2014 to 2015 than the total budget estimates changed—decreasing by as much as 31 percent and increasing by as much as 71 percent—because of changes in programs’ production schedules, scope, the methodology used to develop certain budget estimates, and budgetary structure. Figure 2 provides a comparison of total budget estimates for nuclear modernization activities in NNSA’s 2014 and 2015 budget materials. Table 2, which appears on the next page, details the changes in NNSA’s 25-year budget estimates from 2014 to 2015 for modernization in four program areas: stockpile, infrastructure, ST&E, and other weapons activities.