The nuclear security challenge involves protecting nuclear materials and related technology from theft, diversion, and illicit use, while at the same time allowing for the peaceful use of these materials and technologies. Nuclear security efforts face a wide range of threats. These efforts must be able to address proliferation and security concerns emerging from individual actors, terrorists, transnational networks, and nation states; and they must be sustained into the future. Technology research, development and deployment play a vital role in the implementation of nuclear security requirements and agreements. Technology can be applied in many areas, for example: physical protection—both for materials in place and in transit; understanding threats—both external and the insider threat; the detection of radioactive materials; understanding the characteristics of materials in the context of nuclear fuel cycle processes; and to assist in the enforcement of legal requirements and the verification of treaty agreements. At ORNL, we perform basic research and development of technology to address nuclear security needs, and we deploy those technologies around the world. We have a range of expertise, facilities, and programs that focus on nuclear security challenges, and it is the combination of these activities that assist in meeting the overall mission needs in this area.