Plutonium concentrations in airborne soil at Rocky Flats and Hanford determined during resuspension experiments

Plutonium resuspension results are summarized for experiments conducted by the author at Rocky Flats, onsite on the Hanford reservation, and for winds blowing from offsite onto the Hanford reservation near the Prosser barricade boundary. In each case, plutonium resuspension was shown by increased airborne plutonium concentrations as a function of either wind speed or as compared to fallout levels. All measured airborne concentrations were far below maximum permissible concentrations (MPC). Both plutonium and cesium concentrations on airborne soil were normalized by the quantity of airborne soil sampled. Airborne radionuclide concentrations in ..mu..Ci/g were related to published values for radionuclide concentrations on surface soils. For this ratio of radionuclide concentration per gram on airborne soil divided by that for ground surface soil, there are eight orders of magnitude uncertainty from 10/sup -4/ to 10/sup 4/. This uncertainty in the equality between plutonium concentrations per gram on airborne and surface soils is caused by only a fraction of the collected airborne soil being transported from offsite rather than all being resuspended from each study site and also by the great variabilities in surface contamination. Horizontal plutonium fluxes on airborne nonrespirable soils at all three sites were bracketed within the same four orders of magnitude from 10/sup -7/ to 10/sup -3/ ..mu..Ci/(m/sup 2/ day) for /sup 239/Pu and 10/sup -8/ to 10/sup -5/ ..mu..Ci/(m/sup 2/ day) for /sup 238/Pu. Airborne respirable /sup 239/Pu concentrations increased with wind speed for a southwest wind direction coming from offsite near the Hanford reservation Prosser barricade. Airborne plutonium fluxes on nonrespirable particles had isotopic ratios, /sup 240/Pu//sup 239/ /sup 240/Pu, similar to weapons grade plutonium rather than fallout plutonium

Transuranic resuspension

Characteristics of aged resuspension sources are more uncertain than those of new resuspension sources, which can be investigated using inert-particle controlled-tracer sources. Even though airborne concentrations are low, one aged uniform-area source which can be used for resuspension studies is the accumulated radionuclide fallout in the soil from stratospheric and tropospheric fallout debris. Airborne radionuclide concentrations from this source were investigated at convenient locations on the Hanford site. The objective is to summarize plutonium and americium resuspension research conducted by the Pacific Northwest Laboratory from 1977 to 1983. Airborne plutonium was determined at five sites in the Hanford area, and both plutonium and americium were determined at two Hanford sites. Airborne plutonium and americium were examined as a function of aerodynamic particle diameter, sampling height, wind speed increments, and wind direction increments. The following results are discussed: airborne radionuclide concentrations, ..mu..Ci/cm/sup 3/ of sampled air; radionuclide activity densities, ..mu..Ci/g of airborne solids; airborne plutonium fluxes, ..mu..Ci/(m/sup 2/ day); /sup 241/Am//sup 239 +240/Pu) activity ratios, (..mu..Ci /sup 241/Am)/(..mu..Ci/sup 239 +240/Pu); and airborne solid concentrations, ..mu..g/m/sup 3/ of sampled air. In addition, a relationship based on field data for aged plutonium sources at Bikini Atoll, the Hanford site, and Rocky Flats was developed to estimate the maximum expected plutonium activity density on airborne solids compared to activity densities for bulk surface-soil samples. As a result, it is possible to more accurately predict resuspension factor ranges as a function of the resuspension source activity densities. 31 references, 18 figures, 5 tables

Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

Cyanide and antimony thermodynamic database for the aqueous species and solids for the EPA-MINTEQ geochemical code

Thermodynamic data for aqueous species and solids that contain cyanide and antimony were tabulated from several commonly accepted, published sources of thermodynamic data and recent journal article. The review does not include gases or organic complexes of either antimony or cyanide, nor does the review include the sulfur compounds of cyanide. The basic thermodynamic data, ..delta..G/sub f,298//sup o/, ..delta..H/sub f,298//sup o/, and S/sub f//sup o/ values, were chosen to represent each solid phase and aqueous species for which data were available in the appropriate standard state. From these data the equilibrium constants (log K/sub r,298//sup o/) and enthalpies of reaction (..delta..H/sub r,298//sup o/) at 298 K (25/degree/C) were calculated for reactions involving the formation of these aqueous species and solids from the basic components. 34 refs., 14 tabs

Dry deposition velocities

Dry deposition velocities are very difficult to predict accurately. In this article, reported values of dry deposition velocities are summarized. This summary includes values from the literature on field measurements of gas and particle dry deposition velocities, and the uncertainties inherent in extrapolating field results to predict dry deposition velocities are discussed. A new method is described for predicting dry deposition velocity using a least-squares correlation of surface mass transfer resistances evaluated in wind tunnel experiments. 14 references, 4 figures, 1 table

Model predictions and a summary of dry deposition velocity data

Literature values of independent measurements of dry deposition velocities are summarized as a function of particle diameter and gas speciation. In most of the experiments reported in the literature, there are uncertainties that have hindered the development of general predictive deposition velocity models. However, one model (Sehmel and Hodgson, 1978) offers a more useful approach for predicting particle dry deposition velocities as a function of particle diameter, friction velocity, aerodynamic surface roughness, and particle density