This "Fact Sheet" published by the National Nuclear Security Administration (NNSA) provides an update into actions taken by the Agency to secure its nuclear weapons complexes after 9/11. "The National Nuclear Security Administration (NNSA) has several missions that are critical to the country's national security. NNSA is responsible for securing thousands of nuclear weapons and components, and hundreds of tons of special nuclear material in all forms, shapes and sizes. The eight sites in NNSA's nuclear weapons complex are some of the most secure facilities in the world, because NNSA uses the best, most modern security technology, deploys the most sophisticated assets and has a well-trained, world-class protective force to keep nuclear weapons and material secure. After the 9/11 terrorist attacks, NNSA took steps to protect its critical facilities from vehicle bombs, strengthened its facilities against attacks, and improved the training and equipment of its protective forces. A key to improved security has been consolidating materials and reducing facilities as part of NNSA's future complex-wide transformation efforts."
National Nuclear Security Administration: http://nnsa.energy.gov