Historical Overview of Atmospheric Nuclear Weapons Testing and Estimates of Fallout in the Continental United States

Abstract

From 1945 to 1980, over 500 weapons tests were conducted in the atmosphere at a number of locations around the world. These tests resulted in the release of substantial quantities of radioactive debris to the environment. Local, intermediate, and global fallout deposition densities downwind from test sites depended on the heights of bursts, the yields, and the half-lives and volatilities of the particular fission or activation products, as well as on the meteorological conditions. A number of national and international monitoring programs were established to trace the fallout through the atmosphere and biosphere. These programs included continuous monitoring of ground-level air, exposure rates, and deposition as well as periodic sampling of food, bone, water, soil, and stratospheric air. Although data for specific high-yield tests are still classified, the fission and fusion yields of the various tests and test series have been estimated and from this information the quantities of specific fission and activation products released into the atmosphere have been determined. The geographic and temporal variations in the fallout deposition of specific radionuclides based on both actual measurements and model calculations are discussed in this paper. A feasibility study to estimate the deposition density (deposition per unit area) of particular radionuclides from both Nevada Test Site and "global" fallout on a county-by-county scale for the continental United States is described. These deposition estimates provide a basis for reconstructing population exposure and dose. They support the feasibility of a more detailed evaluation of the population doses that resulted from fallout from atmospheric tests to document the experience fully and to report results more systematically and completely to the world community. The impact of weapons fallout will continue to be felt for years to come since a contaminant baseline has been imposed on the ambient radiation environment that will be an important factor in the assessment of past and future releases of radioactive materials into the biosphere.

Abrupt and moderate climate changes in the mid-latitudes of Asia during the Holocene

“…Vorob'ev and others (2004);16. Carter and Moghissi (1977); Beck and Bennett (2002);17. Valendik (1996); Eruptions dates were taken from the Global Volcanism Program (http://www.volcano.si.edu/world/largeeruptions.cfm) and (Zielinski, 1995). )…”

Waste Isolation Pilot Plant Annual Site Environmental Report for 2013

“…The sample data in Table 4.17 show that Cesium-137 concentrations for 2010 were within the 99 percent confidence interval range of the baseline concentration (4.00E-02 Bq/g). Cesium-137 is a fission product and is ubiquitous in soils because of global fallout from atmospheric nuclear weapons testing (Beck andBennett, 2002 andUNSCEAR, 2000). Co were not detected at any sampling locations (Table 4.17), there was insufficient data to permit any kind of variance analysis between years or among sampling locations.…”

Assinatura da deposição atmosférica de testes nucleares em sedimentos da costa brasileira (240+239Pu e 137Cs)

“…Para latitudes equivalentes, valores maiores de inventários de fallout são observados em climas com maior média anual de precipitações, consequentemente, locais com climas marinhos possuem inventários maiores do que desertos ou padrões de clima úmidos continentais. 21 Existem pequenas diferenças na composição isotópica entre os hemisférios. Levando em consideração que o Pu é sintético em sua origem, sua composição isotópica varia amplamente de acordo com seu mecanismo de produção; dessa forma, a variância intrínseca serve como base para uma grande variedade de possibilidades de uso como traçador de ambientes atmosférico e marinho.…”