From the beginning of the Manhattan Project in the 1940s, a primary mission of DOE and its predecessor organizations has been to design, test, and build the nation’s nuclear weapons. To accomplish this mission, DOE constructed a vast nuclear weapons complex throughout the United States. Much of this complex was devoted to the production and fabrication of weapons components made from two special nuclear materials—plutonium and highly enriched uranium. The end of the Cold War changed the department’s focus from building new weapons to extending the lives of existing weapons, disposing of surplus nuclear material, and cleaning up no longer needed weapons sites. NNSA is responsible for extending the lives of existing weapons in the stockpile and for ultimately disposing of surplus nuclear material, while EM is responsible for cleaning up former nuclear weapons sites. Contractors, who are responsible for protecting classified information, nuclear materials, nuclear weapons, and nuclear weapons components, operate both NNSA and EM sites. In addition to NNSA and EM, DOE has two other important security organizations. DOE’s Office of Security develops and promulgates orders and policies, such as the DBT, to guide the department’s safeguards and security programs. DOE’s Office of Independent Oversight and Performance Assurance supports the department by, among other things, independently evaluating the effectiveness of contractors’ performance in safeguards and security. It also performs follow-up reviews to ensure that contractors have taken effective corrective actions and appropriately addressed weaknesses in safeguards and security. The key component of DOE’s well-established, risk-based security practices is the DBT, a classified document that identifies the characteristics of the potential threats to DOE assets. The DBT has been traditionally based on a classified, multiagency intelligence community assessment of potential terrorist threats, known as the Postulated Threat. The DBT considers a variety of threats in addition to terrorists. Other adversaries considered in the DBT include criminals, psychotics, disgruntled employees, violent activists, and spies. The DBT also considers the threat posed by insiders, individuals who have authorized, unescorted access to any part of DOE facilities and programs. Insiders may operate alone or may assist an adversary group. Insiders are routinely considered to provide assistance to the terrorist groups found in the DBT. The threat from terrorist groups is generally the most demanding threat contained in the DBT. DOE counters the terrorist threat specified in the DBT with a multifaceted protective system. While specific measures vary from site to site, all protective systems at DOE’s most sensitive sites employ a defense-in- depth concept that includes a variety of integrated alarms and sensors capable of detecting intruders; physical barriers, such as fences and antivehicle obstacles; numerous access control points, such as turnstiles, badge readers, vehicle inspection stations, special nuclear material detectors, and metal detectors; operational security procedures, such as a “two person” rule that prevents only one person from having access to special nuclear material; hardened facilities and/or vaults; and a heavily armed paramilitary protective force equipped with such items as automatic weapons, night vision equipment, body armor, and chemical protective gear. Depending on the material, protective systems at DOE Category I special nuclear material sites are designed to accomplish the following objectives in response to the terrorist threat: Denial of access. For some potential terrorist objectives, such as the creation of an improvised nuclear device, DOE may employ a protection strategy that requires the engagement and neutralization of adversaries before they can acquire hands-on access to the assets. Denial of task. For nuclear weapons or nuclear test devices that terrorists might seek to steal, DOE requires the prevention and/or neutralization of the adversaries before they can complete a specific task, such as stealing such devices. Containment with recapture. Where the theft of nuclear material (instead of a nuclear weapon) is the likely terrorist objective, DOE requires that adversaries not be allowed to escape the facility and that DOE protective forces recapture the material as soon as possible. This objective requires the use of specially trained and well-equipped special response teams. The effectiveness of the protective system is formally and regularly examined through vulnerability assessments. A vulnerability assessment is a systematic evaluation process in which qualitative and quantitative techniques are applied to detect vulnerabilities and arrive at effective protection of specific assets, such as special nuclear material. To conduct such assessments, DOE uses, among other things, subject matter experts, such as U.S. Special Forces; computer modeling to simulate attacks; and force-on-force performance testing, in which the site’s protective forces undergo simulated attacks by a group of mock terrorists. The results of these assessments are documented at each site in a classified document known as the Site Safeguards and Security Plan. In addition to identifying known vulnerabilities, risks, and protection strategies for the site, the Site Safeguards and Security Plan formally acknowledges how much risk the contractor and DOE are willing to accept. Specifically, for more than a decade, DOE has employed a risk management approach that seeks to direct resources to its most critical assets—in this case Category I special nuclear material—and mitigate the risks to these assets to an acceptable level. Levels of risk—high, medium, and low—are assigned classified numerical values and are derived from a mathematical equation that compares a terrorist group’s capabilities with the overall effectiveness of the crucial elements of the site’s protective forces and systems. Historically, DOE has striven to keep its most critical assets at a low risk level and may insist on immediate compensatory measures should a significant vulnerability develop that increases risk above the low risk level. Compensatory measures could include such things as deploying additional protective forces or curtailing operations until the asset can be better protected. In response to a September 2000 DOE Inspector General’s report recommending that DOE establish a policy on what actions are required once high or moderate risk is identified, in September 2003, DOE’s Office of Security issued a policy clarification stating that identified high risks at facilities must be formally reported to the Secretary of Energy or Deputy Secretary within 24 hours. In addition, under this policy clarification, identified high and moderate risks require corrective actions and regular reporting. Through a variety of complementary measures, DOE ensures that its safeguards and security policies are being complied with and are performing as intended. Contractors perform regular self-assessments and are encouraged to uncover any problems themselves. In addition to routine oversight, DOE Orders require field offices to comprehensively survey contractors’ operations for safeguards and security every year. These surveys, which can draw upon subject matter experts throughout the complex, generally take about 2 weeks to conduct and cover such areas as program management, protection program operations, information security, nuclear materials control and accountability, and personnel security. The survey team assigns ratings of satisfactory, marginal, or unsatisfactory. DOE’s Office of Independent Oversight and Performance Assurance provides yet another check through its comprehensive inspection program. This office performs such inspections roughly every 18 months at each DOE site that has specified quantities of Category I special nuclear material. All deficiencies (findings) identified during a survey require the contractors to take corrective action. DOE took immediate steps to improve physical security in the aftermath of the September 11, 2001, terrorist attacks. These steps included the following: Raised the level of security readiness. Presidential Decision Directive 39, issued in June 1995, states that the United States shall give the highest priority to developing effective capabilities to detect, prevent, and defeat terrorists seeking nuclear weapons or materials. In response, DOE Notice 473.6 specifies SECONs that have to be implemented at its Category I special nuclear material sites in response to a terrorist threat. On September 11, 2001, within a matter of hours, DOE sites went from their then-normal SECON level 4—terrorist threat level low—to SECON level 2—terrorist threat level high. Sites were required to implement nearly 30 additional measures, such as increasing vehicle inspections and badge checks; increasing stand-off distances between public and sensitive areas to protect against large vehicle bombs; activating and manning emergency operations centers on a continuous basis; and more heavily arming and increasing the number of protective forces on duty. Sites maintained SECON level 2 through October 2001 before dropping to an enhanced SECON level 3. The sites have returned to SECON level 2 several times since September 11, 2001, most recently in December 2003, when the national threat warning system was elevated to Orange Alert. The new baseline for security at DOE sites is generally assumed to be the measures currently associated with SECON level 3. Denial protection strategies. On October 3, 2001, the Secretary of Energy issued a classified directive ordering all sites to develop and implement plans to move to a denial protection strategy. DOE Manual 5632.1C-1 states that a denial protection strategy should be used where unauthorized access presents an unacceptable risk. In this regard, denial programs are designed to prevent an unauthorized opportunity to credibly initiate a nuclear dispersal or detonation or to use available materials for on-site assembly of an improvised nuclear device. Denial has typically been understood to mean that terrorists would never gain access to certain types of special nuclear material. The October 2001 directive also increased levels of performance testing for the protection of special nuclear material at DOE’s most critical facilities to ensure that these denial strategies were effective. Conducted security reviews, studies, and analyses. DOE conducted a number of security-related reviews, studies, and analyses. For example, within days after the terrorist attacks, DOE and NNSA officials conducted a classified assessment of their facilities’ vulnerabilities to an attack by aircraft, such as the attacks that occurred on September 11, 2001, or large vehicle bombs.