The current war with Iraq, international interventions in Afghanistan, and the continuous and seemingly insolvable problems in the Middle East emphasize the importance of supporting stable, healthy countries throughout the Middle East and South and Central Asia. The political alliances and foreign aid promulgated by the Cold War have been seriously strained, creating a more uncertain and unstable international environment. We must stay engaged with this part of the world. New partnerships must be forged. Central Asia represents a mix of political systems - from totalitarian rule to nascent democracy; of economic resources from natural to human; and of cultures from ancient to modern - making it of strategic importance to U.S. national and economic security. The U.S. must remain committed and proactively engaged in the region to promote open and democratic societies attractive to outside investment and to prevent the proliferation of weapons of mass destruction and extremist groups. The U.S is admired for its science and technology and its flexibility in innovation and applying S & T to solve problems. The inherent value that S & T can contribute to advancing U.S. policy goals is the underlying assumption of this report. Science and technology and their applications have much to contribute to social, economic, and environmental sustainability and, therefore, provide a strong foundation for helping the U.S. to implement its policies abroad. The application of concepts such as competition and peer review, open sharing of scientific information through the use of the internet and other information technologies, and the development of international scientific collaborations and networks, can make major contributions to healthy and stable societies in Central Asia. U.S. scientific and technical know-how has much to contribute to U.S. policy goals and easing regional tensions. Science and technology truly can build bridges between nations and cultures while serving the societies in them.

The end of the Cold War allows a comprehensive assessment of the nature and extent of the residual contamination derivative from the atomic defense and nuclear power enterprise in the former Soviet Union. The size of the problem is considerable; some 6.3 x 10{sup 7} TBq (6.4 x 10{sup 8} m{sup 3}) of radioactive waste from the Soviet Union weapons and power complex was produced throughout all stages of the nuclear fuel cycle. The resulting contamination occurs at sites throughout the former Soviet Union where nuclear fuels were mined, milled, enriched, fabricated, and used in defense and power reactors. In addition, liquid radioactive wastes from nuclear reprocessing have been discharged to lakes, rivers, reservoirs and other surface impoundments; military and civilian naval reactor effluents were released to sea as well as stabilized on land. Finally, nuclear testing residuals from atmospheric and underground nuclear tests at the Semipalatinsk and Novaya Zemlya test sites and peaceful nuclear tests conducted throughout the area of the former Soviet Union pose risks to human health and the environment. Through a program of international scientific exchange, cooperative approaches to address these threats provide former Soviet scientists with expertise and technologies developed in the United States, Europe, and elsewhere to design comprehensive and long term remedial solutions. The role of the international community to address these challenges is essential because the emerging states of the former Soviet Union share common nuclear residuals that cross newly established national borders. In addition, the widespread post-Soviet radioactive contamination hampers economic recovery and--in some cases--poses proliferation concerns. Also important is the widespread perception throughout these countries that the Soviet nuclear legacy poses a grave threat to the human population. A new paradigm of ''national security'' encompasses more than the historical activities of nuclear weapon production, testing, and deterrence and now includes the environment, human and economic health, and the proliferation of weapons-of-mass destruction. For these reasons the fall of the Soviet Union provides a new imperative and opportunity for systematic, comprehensive and interdisciplinary international efforts to begin to solve these important environmental problems. The environmental degradation from nuclear contamination affecting states of the former Soviet Union is a large topic, and a full description is outside the scope of this paper. A comprehensive overview of environmental concerns and radioactive waste production, inventories, and impacted sites is provided by others. Portions of the summaries provided here are drawn from these works.

A geochemical software package which models static, single-path kinetic water-rock interactions, EQ3/6 [Wolery, 1979], has been modified to incorporate successive-paths and stationary states under high Peclet number transport conditions in a Lagrangian reference frame [Lichtner, 1988]. These modifications permit calculation of reactive transport with reasonable computational requirements. Results from the new option in EQ3/6 have been compared with analytical results for the simple HCl - SiO2 system; excellent agreements were achieved. Results have also been compared with published results [Lichtner, 1988] for a portion of the Al2O3 - HCl - K2O - SiO2 system. The results are in good qualitative and, in some cases, good quantitative agreement. However, the values of some variables differ substantially; these differences can be attributed to use of a different set of Al and Si aqueous species.

The town of Mailuu-Suu in Kyrgyzstan inherited 23 distinct tailings deposits from Soviet-Era uranium mining operations. Mailuu-Suu is located in the narrow landslide-prone valley of the Mailuu-Suu River about 25 km from the Uzbekistan border. Large-scale release of the radioactive tailings, as a result of landslides, could lead to irreversible contamination of the river and downstream areas. The Mailuu-Suu River is a tributary to the Syr-Darya River, the Fergana valley's main source of irrigation water. The Fergana Valley is a key agricultural region and major population center that spans Kyrgyzstan, Tajikistan, and Uzbekistan. The trans-boundary nature of the Mailuu-Suu tailings issue presents an opportunity for collaboration among these Central Asian states. A cooperative approach to addressing environmental issues such as Mailuu-Suu may contribute to the region's stability by facilitating peaceful associations. Experience from remediation of sites in the US under the Uranium Mill Tailings Remediation Action Project (UMTRA) will be useful in progressing toward remediation at Mailuu-Suu.