Russia, Ukraine, Belarus, and Kazakstan are the focus of this effort because almost all of the fissile material of concern and the bulk of other militarily sensitive items arising from the days of the Soviet Union are found in these countries. Also, these countries were singled out for a range of U.S. cooperative security efforts in the FSU in view of the past deployment of nuclear weapons on their territories.
This study addresses efforts to upgrade the security of stocks of unirradiated uranium enriched to a level of 20 percent or greater (referred to herein as highly enriched uranium or HEU) and of separated plutonium of weapons grade or reactor grade (referred to herein as plutonium). HEU and plutonium are suitable for use in constructing a nuclear weapon without further enrichment or chemical reprocessing; they are thus called direct-use material. Such material is located in hundreds of buildings at widely dispersed sites; most are in Russia, but a few are in Ukraine, Belarus, and Kazakstan.
The study considered various bilateral programs involving U.S. specialists directed to the protection of HEU and plutonium, particularly those managed on the U.S. side by the Department of Energy (DOE). It did not address programs of the U.S. Department of Defense (DOD) concerning direct-use material in weapons or in other forms under the control of the Russian Ministry of Defense. The study did examine DOE efforts to address the security of nuclear fuel of the Russian Navy and civilian icebreaker fleet.
The difficulty in obtaining direct-use material is a principal technical barrier preventing countries of proliferation concern, as well as subnational groups, from acquiring a nuclear weapons capability. Many other components are required to construct a nuclear weapon, but most probably can be more readily obtained than direct-use material. Efforts to prevent wide diffusion of all critical items needed for nuclear weapons have of course been pursued by the United States.
Several kilograms of plutonium or several times that amount of HEU are required to construct a nuclear weapon, with the quantity depending on the composition of the material, type of weapon, and sophistication of the design. Details