Detecting illicit trafficking in nuclear material is complicated because one of the materials of greatest concern—highly enriched uranium—has a relatively low level of radioactivity and is, therefore, among the most difficult to detect. In contrast, medical and industrial radioactive sources, which could be used to construct a dirty bomb, are highly radioactive and, therefore, easier to detect. Although their levels of radioactivity differ, uranium and radioactive sources are similar in that they generally emit only gamma radiation, which is relatively easily shielded when encased in high-density material, such as lead. For example, we reported in March 2005 that a cargo container containing a radioactive source passed through radiation detection equipment DOE had installed at a foreign seaport without being detected because the source was surrounded by large amounts of scrap metal in the container. Plutonium, another nuclear material of great concern, emits both gamma and neutron radiation. Although most currently fielded radiation detection equipment has the capability to detect both gamma and neutron radiation, shielding neutron radiation can be more difficult than shielding gamma radiation. Consequently, plutonium can usually be detected by a neutron detector regardless of the amount of shielding from high-density material. According to DOE officials, neutron radiation alarms are caused only by man-made materials, such as plutonium, while gamma radiation alarms are caused by a variety of naturally occurring sources, including commercial goods such as bananas, ceramic tiles, and fertilizer, as well as by dangerous nuclear materials, such as uranium and plutonium. Because of the complexities of detecting and identifying nuclear material, customs officers and border guards who are responsible for operating detection equipment must be trained in using handheld radiation detectors to pinpoint the source of an alarm, identify false alarms, and properly respond to cases of nuclear smuggling. The manner in which radiation detection equipment is deployed, operated, and maintained can also limit its effectiveness. Given the difficulties in detecting certain nuclear materials and the inherent limitations of currently deployed radiation detection equipment, it is important that the equipment be installed, operated, and maintained in a way that optimizes authorities’ ability to interdict illicit nuclear materials. Although efforts to combat nuclear smuggling through the installation of radiation detection equipment are important, the United States should not and does not rely upon radiation detection equipment at U.S. or foreign borders as its sole means for preventing nuclear materials or a nuclear warhead from reaching the United States. Recognizing the need for a broad approach to the problem, the U.S. government has multiple initiatives that are designed to complement each other that provide a layered defense against nuclear terrorism. For example, DOE works to secure nuclear material and warheads at their sources through programs that improve the physical security at nuclear facilities in the former Soviet Union and in other countries. In addition, DHS has other initiatives to identify containers at foreign seaports that are considered high risk for containing smuggled goods, such as nuclear and other dangerous materials. Supporting all of these programs is intelligence information that can give advanced notice of nuclear material smuggling and is a critical component to prevent dangerous materials from entering the United States. One of the main U.S. efforts providing radiation detection equipment to foreign governments is DOE’s Second Line of Defense program, which began installing equipment at key sites in Russia in 1998. According to DOE, through the end of fiscal year 2005, the program had spent about $130 million to complete installations at 83 sites, mostly in Russia. Ultimately, DOE plans to install radiation detection equipment at a total of about 350 sites in 31 countries by 2012 at a total cost of about $570 million. In addition to DOE’s efforts, other U.S. agencies also have programs that provide radiation detection equipment and training to foreign governments. Two programs at DOD—the International Counterproliferation Program and Weapons of Mass Destruction Proliferation Prevention Initiative—have provided equipment and related training to eight countries in the former Soviet Union and Eastern Europe at a cost of about $22 million. Similarly, three programs at State—the Nonproliferation and Disarmament Fund, Georgia Border Security and Law Enforcement program, and Export Control and Related Border Security program—have spent about $25 million to provide radiation detection equipment and training to 31 countries. However, these agencies face a number of challenges that could compromise their programs’ effectiveness, including (1) corruption of foreign border security officials, (2) technical limitations of equipment at some foreign sites, (3) problems with maintenance of handheld equipment, and (4) the lack of infrastructure and harsh environmental conditions at some border sites. First, according to officials from several recipient countries we visited, corruption is a pervasive problem within the ranks of border security organizations. DOE, DOD, and State officials told us they are concerned that corrupt foreign border security personnel could compromise the effectiveness of U.S.-funded radiation detection equipment by either turning off equipment or ignoring alarms. To mitigate this threat, DOE and DOD plan to deploy communications links between individual border sites and national command centers so that alarm data can be simultaneously evaluated by multiple officials, thus establishing redundant layers of accountability for alarm response. In addition, DOD plans to implement a program in Uzbekistan to combat some of the underlying issues that can lead to corruption through periodic screening of border security personnel. Second, some radiation portal monitors that State and other U.S. agencies previously installed have technical limitations: they can detect only gamma radiation, making them less effective at detecting some nuclear material than equipment with both gamma and neutron radiation detection capabilities. Through an interagency agreement, DOE assumed responsibility for ensuring the long-term sustainability and continued operation of radiation portal monitors and X-ray vans equipped with radiation detectors that State and other U.S. agencies provided to 23 countries. Through this agreement, DOE provides spare parts, preventative maintenance, and repairs for the equipment through regularly scheduled maintenance visits. Since 2002, DOE has maintained this equipment but has not upgraded any of it, with the exception of at one site in Azerbaijan. According to DOE officials, new implementing agreements with the appropriate ministries or agencies within the governments of each of the countries where the old equipment is located are needed before DOE can install more sophisticated equipment. Third, since 2002, DOE has been responsible for maintaining certain radiation detection equipment previously deployed by State and other agencies in 23 countries. However, DOE is not responsible for maintaining handheld radiation detection equipment provided by these agencies. As a result, many pieces of handheld equipment, which are vital for border officials to conduct secondary inspections of vehicles or pedestrians, may not function properly. For example, in Georgia, we observed border guards performing secondary inspections with a handheld radiation detector that had not been calibrated (adjusted to conform with measurement standards) since 1997. According to the detector’s manufacturer, yearly recalibration is necessary to ensure that the detector functions properly. Finally, many border sites are located in remote areas that often do not have access to reliable supplies of electricity, fiber optic lines, and other infrastructure essential to operate radiation detection equipment and associated communication systems. Additionally, environmental conditions at some sites, such as extreme heat, can affect the performance of equipment. To mitigate these concerns, DOE, DOD, and State have provided generators and other equipment at remote border sites to ensure stable supplies of electricity and, when appropriate, heat shields or other protection to ensure the effectiveness of radiation detection equipment. We also reported that State’s ability to carry out its role as lead interagency coordinator of U.S. radiation detection equipment assistance has been limited by deficiencies in its strategic plan for interagency coordination and by its lack of a comprehensive list of all U.S. radiation detection equipment assistance. In response to a recommendation we made in 2002, State led the development of a governmentwide plan to coordinate U.S. radiation detection equipment assistance overseas. This plan broadly defines a set of interagency goals and outlines the roles and responsibilities of participating agencies. However, the plan lacks key components, including overall program cost estimates, projected time frames for program completion, and specific performance measures. Without these elements in the plan, State will be limited in its ability to effectively measure U.S. programs’ progress toward achieving the interagency goals. Additionally, in its role as lead interagency coordinator, State has not maintained accurate information on the operational status and location of all radiation detection equipment provided by U.S. programs. While DOE, DOD, and State each maintain lists of radiation detection equipment provided by their programs, they do not regularly share such information, and no comprehensive list of all equipment provided by U.S. programs exists. For example, according to information we received from program managers at DOE, DOD, and State, more than 7,000 pieces of handheld radiation detection equipment had been provided to 36 foreign countries through the end of fiscal year 2005. Because much of this equipment was provided to the same countries by multiple agencies and programs, it is difficult to determine the degree to which duplication of effort has occurred. Without a coordinated master list of all U.S.-funded equipment, program managers at DOE, DOD, and State cannot accurately assess if equipment is operational and being used as intended, determine the equipment needs of countries where they plan to provide assistance, or detect whether an agency has unknowingly supplied duplicative equipment. Through December 2005, DHS had installed about 670 radiation portal monitors nationwide— about 22 percent of the portal monitors DHS plans to deploy—at international mail and express courier facilities, land border crossings, and seaports in the United States. DHS has completed portal monitor deployments at international mail and express courier facilities and the first phase of northern border sites—57 and 217 portal monitors, respectively. In addition, by December 2005, DHS had deployed 143 of 495 portal monitors at seaports and 244 of 360 at southern border sites.