In-situ measurement of radionuclides in the environment with a Ge(Li) spectrometer.

Abstract

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Resuspension and Redistribution of Plutonium in Soils

“…al.., 1973), but a longer half-time of decrease of about 10 weeks vas observed by Anspaugh, et al. (1973) during one experiment conducted 12 to ho veeks post re lease ar-i Sehmel and Orgill (197't) reported a half-time of about 9 months after a 10 year old source had been artificially disturbed; 3) Such long-term decreases of the concentration of resuspended radionuclides with time are not due to an appreciable net loss of radionuclide from the area, but to a "weathering" process whereby the contaminant becomes less erodible (Shreve, 1958;Olafson and Larson, 1961;Stewart, 196U;Larson, et_ aj^., 1966); k) Areas which were contaminated 10 to 20 years previously are still significant sources of resuspended radioactive par ticulates {Anspaugh, et a^.…”

“…, 197trt>;197'tc;Sehmel and Orgill, 19714); 5) For explosion-produced sources, the quotient of j.ir concentration of resuspended contaminant divided by ground deposition increases with dis tance from the source (Wilson, et al, I960;Larson, et al, 1966;Anspaugh, et_ al., 1971) which may be partly due to the decrease in par ticle size of the contaminant which is deposited at further distances (Shreve, 1958); 6) Short-term, order of magnitude fluctuations of the airborne concentration of resuspended radionuclides are frequently observed presumably due to changes in meteorological conditions although functional relationships are not well-defined, especially for freshly deposited sources (Shreve, 1958;Wilson, et. al., ?960;Olafson and Larson, 196l;Larson, et al, 1966;Anspaugh, et al_., 1973); 7) Arti ficial disturbances in a contaminated environment can also produce orders of magnitude increases in the airborne concentration of contaminant (Mork, 1970;Sehmel, 1973;Sehmel and Orgill, 197't); and 8) Measurements of the particle size distributions of resuspended, plutonium-containina: aerosols indicate that the fraction which vould undergo pulmonary depo sition is about 0.15 to 0.25 (Wilson, et <a., I960;Volchok and Knuth, 1972;Anspaugh, et_ al., 197i»o).…”

“…Several general conclusions may, however, be drawn from these experi ments: l) The airborne concentration of radioactive aerosols produced by explosions declines rapidly immediately after the detonation and is lower by a factor of 100 to 1000 by 100 hr after the detonation (Shreve, 1958;Anspaugh, et_ al.., 1973); 2) After the initial vapid decline, a further decrease with tiEe is noted with half-times of about 5 weeks observed during the first 6 to 20 weeks following release (Langham, 1971;Larson, et_ al., 1966;Anspaugh, et. al.., 1973), but a longer half-time of decrease of about 10 weeks vas observed by Anspaugh, et al.…”

A Methodology for Evaluating the Toxicity of Radioactive Waste and Its Application to the Radioactive Waste Generated in Pennsylvania

“…Although this must ultimately be determined based on specific local conditions, it appears to be a reasonable assumption for purposes of this methodology. Several researchers have measured gamma emitters in soil that reasonably confirm this assumption beyond the radon gas decay products (Anspaugh et al 1972;Bolch et al 1976). The specific activity of some I' Depending on site specific conditions, soil specific activities could vary by a factor of about 0.5 to 5 times these assumed values.…”