"The United States intends to invest about $80 billion to maintain and modernize its nuclear weapons capabilities and infrastructure over the next decade. The National Nuclear Security Administration (NNSA), a semi-autonomous agency within the Department of Energy (DOE), maintains the nation's nuclear weapons through its Stockpile Stewardship Program (SSP). NNSA uses contractors to manage and operate eight separate sites, referred to as the nuclear security enterprise, to achieve the SSP's mission.The National Defense Authorization Act for Fiscal Year 2010 directed GAO to review the SSP. This report focuses on the extent to which NNSA has the data necessary to make informed, enterprisewide decisions, particularly data on the condition of infrastructure, capital improvement projects, shared use of facilities, and critical human capital skills. GAO analyzed agency infrastructure data; reviewed agency directives and guidance; and interviewed DOE, NNSA, and contractor officials."