With the end of the Cold War, the US and the Russian Federation have been actively dismantling tens of thousands of nuclear weapons. As a result, large quantities of fissile materials have become surplus to the strategic defence needs of both countries. In order to meet non-proliferation goals and to ensure the irreversibility of nuclear arms reductions, these excess fissile materials must be placed and maintained in secure storage prior to being dismantled and, ultimately, processed into a form that meets the "spent fuel" standard. A fundamental prerequisite for the successful disposal of these materials is the safe operation of the many components of the nuclear fuel cycle. The present book reports on a technical exchange between the US Department of Energy and the Russian Ministry for Atomic Energy, with additional input from expert organizations in other countries, on the issue of nuclear materials safety management. It addresses the principal issues in the area, summarizes past activities, and outlines potential future initiatives. The focus is on the non-reactor components of the nuclear fuel cycle, with consideration of excess weapons fissile materials. Coverage includes storage of plutonium; plutonium oxide manufacture, storage, and transportation; mixed oxide fuel fabrication, storage, and transportation; and spent fuel and waste issues.