Congress established the Council in the National Defense Authorization Act for Fiscal Year 1987. The structure, membership, and responsibilities of the Council are generally found in section 179 of Title 10, U.S. Code. A 1997 memorandum of agreement between DOD and DOE identified several activities for the Council to perform in support of its statutory responsibilities, including establishing support committees; providing guidance to the support committees; and reviewing and acting on recommendations on the nuclear weapons stockpile from the support committees. The memorandum also states that the Council will establish, and modify as necessary, its own procedures. The membership of the Council is established by statute. The Council designates the voting members of its support committees, which include a senior executive-level Standing and Safety Committee and a subordinate, working-level Action Officers Group. The Council and its support committees also include nonvoting participants—referred to as observers and technical advisors—who attend meetings to provide their particular expertise. For example, representatives from the NNSA laboratories attend as technical advisors, and representatives from the Navy’s Strategic Systems Programs office may attend as observers. Figure 1 shows the membership of the Council and its support committees as of March 2015, based on the unofficial Nuclear Matters Handbook and information provided by the Council staff. According to DOD’s unofficial Nuclear Matters Handbook and Council staff, the Council conducts day-to-day operations and coordinates issues through its hierarchy of support committees. The Action Officers Group performs detailed analyses of issues and provides those analyses to the Standing and Safety Committee, which reviews them and formulates decision packages for final Council review and decision. An issue may be sent to a lower-level committee if a higher-level committee determines that further review and analysis are needed. Issues move to the next higher or lower committee based on a consensus decision of the members. Figure 2 illustrates the decision-making process of the Council and its support committees, as described by the unofficial Nuclear Matters Handbook and DOD and NNSA officials. According to DOD’s unofficial Nuclear Matters Handbook and Council staff, the frequency and timing of Council and support committee meetings are intended to support this decision-making process. In general, the Action Officers Group meets about twice a month. The Standing and Safety Committee meets about once a month, after an Action Officers Group meeting, so that it can receive results from the Action Officers Group meetings. Likewise, the full Council also meets about once a month, after the Standing and Safety Committee meeting, so that the Council can receive the results from the Standing and Safety Committee. A key function of the Council is to provide oversight of the refurbishment of nuclear weapons. In 2000, the Council developed a standard process—called the Phase 6.X process—which provides a joint framework for refurbishing nuclear weapons in order to extend their operational lives. The Phase 6.X process includes various program review and decision points that require Council approval before moving forward to the next phase. For example, the Procedural Guideline for the Phase 6.X Process requires the program office to obtain the Council’s approval before beginning a feasibility study, development engineering, or full-scale production phases. In October 2005, we identified key practices that can help enhance and sustain collaboration among federal agencies. Among the practices we identified were (1) defining and articulating a common outcome; (2) establishing mutually reinforcing or joint strategies; (3) identifying and addressing needs by leveraging resources; (4) developing mechanisms to monitor, evaluate, and report on results; (5) reinforcing agency accountability for collaborative efforts through agency plans and reports; (6) establishing compatible policies, procedures, and other means to operate across agency boundaries; and (7) agreeing on roles and responsibilities. In September 2012, we found that although collaborative mechanisms differed in complexity and scope, they all benefited from certain key practices, many of which we had identified in October 2005. Accordingly, in our 2012 report, we built on our past work and identified key issues to consider when implementing collaborative mechanisms. Among the key considerations we identified were whether the participating agencies documented their agreement regarding how they will be collaborating; whether participating agencies developed ways to continually update or monitor written agreements; and whether all relevant participants had been included. The Council carries out its statutory and regulatory responsibilities in a number of ways, including by developing requirements documents on the size and composition of the nuclear weapons stockpile, providing oversight of nuclear weapons refurbishment programs, and coordinating budget matters to support the stockpile. However, the Council faces several challenges in carrying out its assigned responsibilities, including executing new budget-related responsibilities; planning for a greater number of weapon refurbishment programs than in the past; and adjusting program priorities in response to budget pressures. According to DOD and DOE officials, the Council takes various actions to carry out its responsibilities, many of which are related to nuclear weapons programs. The Council’s responsibilities are laid out in law and in a 1997 memorandum of agreement between DOD and DOE. The Council’s actions include stockpile management (i.e., developing requirements documents on the size and composition of the nuclear weapons stockpile), providing oversight of weapons refurbishment programs, and coordinating budget matters to support the stockpile. The National Defense Authorization Act for Fiscal Year 2013 gave the Council several new budget-related responsibilities, such as certifying to Congress whether the annual budget request for NNSA meets stockpile program requirements, and approving programming and budget matters pertaining to nuclear weapons programs between DOD and DOE. Table 1 shows some of the Council’s statutory responsibilities and the actions it takes to carry out each of them, according to information and documentation provided by the Council staff. In addition to these responsibilities, the Council is to assess the NNSA Stockpile Stewardship Management Plan and determine whether the plan supports the requirements of the National Security Strategy or the most recent Quadrennial Defense Review and the Nuclear Posture Review. According to DOD’s unofficial Nuclear Matters Handbook, the Council also is to coordinate the annual Joint Surety Report—which assesses nuclear weapon safety and security—and send the report to the Secretaries of Defense and Energy for signature. Finally, the Council is to prepare a number of reports for Congress or congressional committees on matters that include weapons refurbishment programs and stockpile- management issues. The Council faces several challenges in carrying out its responsibilities. Specifically, the Council faces challenges in (1) carrying out several new budget-related responsibilities; (2) planning and providing oversight for more nuclear weapon refurbishment programs than it has in the past; and (3) adjusting program priorities in response to budget pressures. The National Defense Authorization Act for Fiscal Year 2013 added several new responsibilities for the Council, including approving programming and budget matters pertaining to nuclear weapons programs and submitting a certification on whether the annual budget request for NNSA and its planned budget for the 4 years thereafter meet nuclear stockpile requirements. According to DOD and NNSA officials, these additional responsibilities require a significant amount of the Council’s time and reduce the time it has to focus on carrying out its traditional stockpile responsibilities. In addition, DOD and NNSA officials told us that requirements for implementing some of these new responsibilities are not clear. For example, the DOD officials we spoke with expressed confusion over what might constitute “certification” of the budget request for NNSA. The Council has met this annual responsibility with a letter to the Senate and House Appropriations and Armed Services Committees, as well as the President of the Senate and Speaker of the House, explaining that the budget request for NNSA includes risks that could increase if funding is reduced or if savings from NNSA initiatives are not achieved. Though the Council has new budget-related responsibilities, officials told us that while the Council can coordinate across DOD and NNSA to revise plans and programs in response to changes in budgets, funding, or cost estimates, it cannot direct the work of DOD or NNSA and has no budget-development or formal approval authority. For example, officials stated that while the Council is responsible for certification of the budget request for NNSA, it does not have the authority to direct changes to either DOD or NNSA’s work or formally approve their budgets. Another challenge the Council faces is planning and providing oversight for more nuclear weapon refurbishment programs than it has in the past. For example, in 2008, the Council provided oversight for two refurbishment programs. As of November 2014, the Council is providing oversight for four such programs and is planning for three additional programs for different types of interoperable warheads. As a result, according to Council staff, the Council’s oversight role has increased and it is challenged in working to adjust program priorities to align with available resources. Finally, the Council has adjusted program priorities for the nuclear weapons enterprise in response to budget pressures. For example, under funding limitations resulting from the Budget Control Act of 2011, as amended, DOD estimates reductions in planned defense spending from fiscal years 2012 through 2021 will exceed $1 trillion. NNSA has similarly projected reductions in the level of spending it had planned for the 5-year future years nuclear security program. Also, some NNSA nuclear weapon programs have experienced delays and cost growth during the past 5 years. For example, the cost estimate for one life extension program has more than doubled since 2010. According to NNSA’s Stockpile Stewardship Management Plan for Fiscal Year 2015 and DOD and NNSA officials, due to these increased costs and budget constraints, the Council has needed to adjust program priorities for the nuclear weapons enterprise by, for example, extending the date when the first units will be produced for four programs. Further, the Council has faced emerging issues—such as the increased scope of one refurbishment program—that necessitated additional funding and therefore an assessment of and decision on how such a change may affect the long-term baseline plan.