Nuclear weapon testing

The rate of release of to the atmosphere from these weapons tests, as estimated from the detailed data in the two references and from a yield qf 50 /iCi per JCT Pu fission, are tabulated in Table 3.1. 

Nuclear weapons tests since 1970 have added very little to the inventory hence, the total is still close to 10 Ci. This amount of js less than the inventory of natural ( 40 Ci) existing prior to f945 (see Section 2.2). 

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Eisenberg et al. (1975) developed estimates of fatalities due to thermal radiation damage using data and correlations from nuclear weapons testing. The probability of fatality was found to be generally proportional to the product where t is the radiation duration and 7 is the radiation intensity. Table 6.7 shows the data used to develop estimates of fatalities from thermal radiation data. 

The earliest tables were compiled from data collected from nuclear weapon tests, in which very high yield devices produced sharp-peaked shock waves with long durations for the positive phase. However, these data are used for other types of blast waves as well. Caution should be exercised in application of these simple criteria to buildings or structures, especially for vapor cloud explosions, which can produce blast waves with totally different shapes. Application of criteria from nuclear tests can, in many cases, result in overestimation of structural damage. 

Andrei Sakliarov was a Soviet physicist who became, in the words of the Nobel Peace Prize Committee, a spokesman for the conscience of mankind. He made many important contributions to our understanding of plasma physics, particle physics, and cosmology. He also designed nuclear weapons for two decades, becoming the father of the Soviet hydrogen bomb in the Ih.SOs. After recognizing the dangers of nuclear weapons tests, he championed the 1963 U.S.-Soviet test ban treaty and other antinuclear initiatives. 

Air and natural gas have also been used as drilling fluids in slim-hole-drilling mining operations, special large-diameter boreholes for nuclear weapons tests, and, more recently, in geothermal drilling operations. 

The radiation hazard associated with fallout from nuclear weapons testing arises from radioactive isotopes such as these. One of the most dangerous is strontium-90. In the form of strontium carbonate, SrC03, it is incorporated into the bones of animals and human beings, where it remains far a lifetime. 

The major source of plutonium in natural waters is the atmospheric fallout from nuclear weapons tests. Fallout plutonium is ubiquitous in marine and freshwater environments of the world with higher concentrations in the northern hemisphere where the bulk of nuclear weapons testing occurred(3). Much of the research on the aquatic chemistry of plutonium takes place in marine and freshwater systems where only fallout is present. 

Atmospheric fallout from nuclear weapon tests and aquatic... 

Goldsmith, P., Tuck, A. F., Foot, J. S., Simmons, E. L., and Newson, R. L. (1973). Nitrogen oxides, nuclear weapon testing, Concorde, and stratospheric ozone. Nature 244, 545-551. 

Care must also be taken to not confuse the perturbation, e.g. from nuclear weapons testing with the ACO2 perturbation lifetime. The former is largely due to fast isotopic exchange while the latter is controlled by a slower mass flux. 

Am released to the atmosphere will be associated with particles and will settle to earth or be washed from the air in precipitation (e.g., rain, snow). 241 Am from atmospheric nuclear weapons tests is injected into the stratosphere and may remain in the atmosphere for decades, traveling all around the world and only slowly settling to earth. 241 Am released in nuclear accidents, like Chernobyl, stays in the lower atmosphere where it can begin settling out near the site from which it is released. Larger particles will settle out more quickly and over a smaller area smaller particles may remain in the atmosphere for several months and travel far from where they are released. Precipitation scrubs particles out of the air more rapidly and deposits them in areas where the precipitation occurs. 

Exposure of the general population to 241 Am via air, water, soil, and food are generally very low these background levels are a result of fallout from past atmospheric nuclear weapons tests. Since 1973, 241Am air concentrations have been less than 1 aCi/m3 (0.037 pBq/m3) and are continuing to decline (Bennett 1979). Levels around nuclear power plants are indistinguishable from fallout background (EPRI 1981). 

Nuclear Weapons Testing Range, Maralinga, South Australia, site of 12 hydronuclear experiments at Taranaki in 1960, 1961, and 1963 (Vixen B Trials) in which 22.2 kg of plutonium was dispersed, having been ejected 2,500feet vertically into the atmosphere. Cooper etal. 1994... 

Denmark 1.5 days after the explosion. Air samples collected at Roskilde, Denmark on April 27-28, contained a mean air concentration of 241Am of 5.2 pBq/m3 (0.14 fCi/m3). In May 1986, the mean concentration was 11 pBq/m3 (0.30 fCi/m3) (Aarkrog 1988). Whereas debris from nuclear weapons testing is injected into the stratosphere, debris from Chernobyl was injected into the troposphere. As the mean residence time in the troposphere is 20-40 days, it would appear that the fallout would have decreased to very low levels by the end of 1986. However, from the levels of other radioactive elements, this was not the case. Sequential extraction studies were performed on aerosols collected in Lithuania after dust storms in September 1992 carried radioactive aerosols to the region from contaminated areas of the Ukraine and Belarus. The fraction distribution of241 Am in the aerosol samples was approximately (fraction, percent) organically-bound, 18% oxide-bound, 10% acid-soluble, 36% and residual, 32% (Lujaniene et al. 1999). Very little americium was found in the more readily extractable exchangeable and water soluble and specifically adsorbed fractions. 

Cooper MB, Bums PA, Tracy BL, et al. 1994. Characterization of plutonium contamination at the former nuclear weapons testing range at Maralinga in South Australia. J Radioanal Nucl Chem 177(1) 161-184. 

Contamination of food crops by radiocerium in fallout from nuclear weapons tests has been extensively documented in the worldwide literature (Chhabra and Hukkoo, 1962 Merk, 1967 Michelson et al., 1962 Nezu et al., 1962 Sutton and Dwyer, 1964). The 144Ce concentrations in spinach leaves and radish roots in Japan in 1960 were within a factor of two of the respective "Sr concentrations (Nezu et al., 1962). 

Noyce, J. R., Moore, D. T., Sherwood, J. D., Daniel, P. R., Beck, J. N. and Kuroda, P. K. (1973). Fallout from nuclear weapons testing and interhemispheric transport of nuclear debris, Health Phys. 25, 109. 

Again the atmospheric 14C/C ratio is an excellent example. Man-induced disturbances of the environmental system lead to changes in the 14C/C ratio which are of the order of magnitude of the natural fluctuations or even larger the emission of 14C-free C02 from fossil energy consumption leads to a decrease, and the emission of man-made 14C from nuclear weapons testing, to an increase of the atmospheric 14C/C ratio. 

During the industrial era man has influenced the atmospheric 14C/C ratio. By 1950 input of C02 from combustion of fossil fuel had led to a decrease in this ratio of about 2 percent. By 1963 due to nuclear weapon tests, however, the atmospheric 14C level in the northern hemisphere had increased by about 100 percent. The present excess is still v30 percent. There is also an input of 14C from nuclear power and reprocessing plants. 

There would be, however, a considerable discrepancy between the model-calculated dilution factor and the dilution factor required if the biospheric C02 input were of comparable size as the fossil C02 input as stated by biologists [43]. For a discussion of this question see also Oeschger et al., [39]. Thirdly, we calculate the 14C dilution corresponding to the CO increase. In 1950, before the nuclear weapon tests, the integrated C02 production amounted to about 10 percent of the preindustrial atmospheric C02 content. If there had been no exchange with other reservoirs, a decrease of the 14C/C ratio by 10 percent would have resulted. Tree-ring 14C measurements indicated, however, a decrease by only about 2 percent. Again we calculate the system dilution. In a first approximation 4 and s are set equal to one and we obtain... 

Annual effective dose equivalent from nuclear weapons testing to humans in the north temperate zone... 

Nuclides formed as a result of nuclear weapons tests, nuclear reactor operations, and other human activities. Important members of this group include 90Sr, 137Cs, 14C, and 3H note that many members of the third group — such as 14C and 3H — are also formed in this fourth fashion (Rose et al. 1990). 

Table 32.7 Annual Effective Dose Equivalent from Nuclear Weapons Testing to Humans in the North Temperate Zone... 

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