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.

It is well recognized that half the countries in the world will face significant fresh water shortages in the next 20 years, due largely to growing populations and increased agricultural and industrial demands (Gleick, 1997). These shortages will significantly limit economic growth, decrease the quality of life and human health for billions of people, and could potentially lead to violence and conflict over securing scarce supplies of water. In the Middle East, groundwater represents an important part of water supply in most locations, yet it is the least understood and one of the most fragile components of the entire water resource system. The occurrence of water underground contributes to the illusion of an infinite resource that is immune to anthropogenic activities. Nevertheless, as has been learned in the West, it can become highly impaired through the actions of man--through the disposal of human, animal, or industrial wastes, from excessive irrigation and fertilization practices in agriculture, or from simple overproduction and overexploitation--and can remain so for decades or even centuries. Finding solutions to groundwater resource and quality problems can be complex, time consuming, and costly. As is the case in many places in the world, but especially in the Middle East, there is a large gap between professionals, policy makers, and the general population with respect to their understanding of groundwater, its abundance, distribution, movement, and pollution. In a region where water supply and quality problems can be extremely acute, it becomes that much more necessary to protect and preserve the water that does exist. To sustain groundwater as a long-term reliable resource, increased understanding of factors affecting both the quality and quantity of groundwater must be better understood by all aspects of society. This report describes the outcome of a collaborative project between Lawrence Livermore National Laboratory (LLNL) in the US and the Jordan University of Science and Technology (JUST), the Ministry of Water and Irrigation (MWI), and the Royal Society for the Conservation of Nature (RSCN), all in Jordan. The project was funded by the United States Information Agency (now known as the Bureau of Educational and Cultural Affairs of the US Department of State) and the Lawrence Livermore National Laboratory, University of California. It was designed to develop, utilize, and distribute a series of educational tools across a wide spectrum of the population in Jordan to illustrate the impact of human activities and policies on the use and preservation of groundwater as an increasingly precious resource. The educational tools involved (1) portable, two-dimensional physical groundwater models for use in educating primary-aged children, laypersons, academic, government, other technical professionals, and farming communities on basic groundwater issues, and (2) computer-based simulation software, which can be used to assess the accrual and movement of groundwater in actual geologic formations, as well as the fate of contaminants that reach and dissolve within groundwater. These tools have an uncommon capacity to illustrate the impact of human activities and policies to a broad spectrum of the population that includes school children, college and post-graduate students, government officials, civic groups, professional organizations, and all, citizens.

The purpose of this report is to assess the decay and in-growth of radionuclides from the radionuclide source term (RST) deposited by underground nuclear weapons tests conducted at the NTS from 1951 through 1992. A priority of the Underground Test Area (UGTA) project, administered by the Environmental Restoration Division of NNSA/NV, was to determine as accurately as possible a measure of the total radionuclide inventory for calculation of the RST deposited in the subsurface at the Nevada Test Site (NTS). The motivation for the development of a total radionuclide inventory is driven by a need to calculate the amount of radioactivity that will move away from the nuclear test cavities over time, referred to as the hydrologic source term (HST). The HST is a subset of the RST and must be calculated using knowledge of the geochemistry and hydrology of the subsurface environment. This will serve the regulatory process designed to protect human health from exposures to contaminated groundwater. Following the detonation of an underground nuclear test, and depending on the presence of water at the location of the detonation, the residual radionuclides may be found in aqueous or gaseous states, precipitated or chemically sorbed states, or incorporated in melt glass produced by the nuclear test. The decay and in-growth of radionuclides may have geochemical implications for the migration of radionuclides away from underground nuclear test cavities. For example, in the case of a long-lived mobile parent decaying to a shorter-lived and less mobile daughter, the geochemical properties of the parent element may control the migration potential of the daughter nuclide. It becomes important to understand the evolution of the RST in terms of effects on the mobility, solubility, or abundance of radionuclides in the HST that are created by decay and in-growth processes. The total radionuclide inventory and thus the RST changes with time due to radioactive decay. The abundance of a specific radionuclide at any given time is a function of the initial amount of radioactivity, the decay rate and in-growth from parent radionuclides. The in-growth of radioactivity is the additional amount of radioactivity for a given radionuclide that comes from the decay of the parent isotopes. In this report, decay and in-growth of radionuclides from the RST are evaluated over the 1000-year time frame in order to determine whether coupled in-growth and decay affect the relative abundance of any RST radionuclide. In addition, it is also necessary to identify whether any new derivative radionuclides not initially produced by the nuclear test but exist now as a result of in-growth from a parent radionuclide One of the major goals of this report is to simplify the transport modeler's task by pointing out where in-growth is unimportant and where it needs to be considered. The specific goals of this document are to evaluate radionuclide decay chains and provide specific recommendations for incorporating radionuclide daughters of concern in the calculation of the radionuclide inventory.