Nuclear Nonproliferation: DOE Made Progress to Secure Vulnerable Nuclear Materials Worldwide, but Opportunities Exist to Improve Its Efforts, Report to Congressional Requesters [open pdf - 2MB]
"In April 2009, President Obama announced an initiative to secure all vulnerable nuclear materials -- such as those that could be stolen by terrorists and used to construct a nuclear device -- within 4 years. DOE [Department of Energy] is primarily responsible for activities under this initiative, but the Nuclear Regulatory Commission (NRC), the Department s of Defense (DOD) and State, and the National Security Council (NSC) also have roles. GAO [Government Accountability Office] was asked to examine actions taken under this initiative. This report (1) assesses the extent to which DOE achieved its goals for four key activities under the initiative and (2) examines DOE's goals going forward and assesses challenges that may limit its ability to secure additional vulnerable nuclear materials. GAO reviewed relevant documents and interviewed officials from DOE, NRC, DOD, and State, as well as discussed these issues with officials from NSC and selected foreign government agencies. This is a public version of a classified report GAO issued in August 2015. […] GAO continues to believe that DOE and other U.S. agencies should complete an inventory of U.S. plutonium at worldwide sites as GAO recommended in September 2011. In this report, GAO recommends that DOE complete its prioritization of nuclear materials at foreign locations. GAO also recommends that DOE and other agencies visit sites containing key quantities of U.S nuclear materials that have not been visited in at least 5 years. DOE agreed with GAO's recommendations."
Government Accountability Office: http://www.gao.gov/