Plutonium occurs throughout the earth’s environmental systems, though usually in quantities so small that they are barely detectable. Because this artificial element is so toxic, it is necessary to identify those few locations where the concentrations are likely to be the highest. Because almost all plutonium released into the environment is ultimately attached to soil and sediment particles, the behavior of constantly changing natural transport systems such as water and sediment flows provide the key to understanding the ultimate geographic disposition of the element. The general purpose of the work discussed in this book is to explain the distribution of plutonium in the Northern Rio Grande system of northern New Mexico and southwestern Colorado by forging a link among the available data and general principles of environmental sciences such as hydrology, geomorphology, and radioecology. Between 1945 and 1952, Los Alamos National Laboratory handled large amounts of plutonium as part of the Manhattan Project (the effort to construct the first atomic weapons) and as part of the weapons programs related to the early years of the cold war. During this time, the laboratory emptied untreated plutonium waste into the alluvium of Los Alamos Canyon. After 1952, the laboratory released relatively small amounts of treated plutonium waste. Although the vertical movement of plutonium through the alluvial materials has been largely limited to the upper 10 m,4 the horizontal movement of the contaminants has had much larger dimensions. The plutonium was adsorbed onto sedimentary particles, and so the fate of those sediments is also the fate of the plutonium. Natural processes of erosion have resulted in substantial movement of contaminated sediments through the canyons. Research during the 1960s and early 1970s showed that since the war years, surface flows within the laboratory’s boundaries had redistributed at least some of plutonium. Laboratory researchers later estimated that fluvial (river-related) processes in Los Alamos Canyon had probably removed significant quantities from the laboratory area by carrying the plutonium into the Rio Grande. They predicted that early in the twenty-first century almost all of the plutonium would have been emptied from Los Alamos Canyon into the Rio Grande.
The Los Alamos Computing Facility During the Manhattan Project
