Plutonium aerosols

Plutonium aerosols can be formed in various ways, including ... 

Table 5.2. Plutonium aerosols in ventilation ducts ofUSAECplants (Elder etal., 1974)...

Elder, J.C., Gonzales, M. Ettinger, H.J. (1974) Plutonium aerosol size characteristics. Health Physics, 27, 45-53. 

Moss, W.D., Hyatt, E.C. Schulte, H.F. (1961) Particle size studies on plutonium aerosols. Health Physics, 5, 212-18. 

Shinn, J.H., Homan, D.N. Gay, D.D. (1983) Plutonium aerosol fluxes and pulmonary exposure rates during re-suspension from bare soils near a chemical separation facility. In Precipitation Scavenging, Dry Deposition and Re-suspension, ed. H.R. Pruppacher, R.G. Semonin W.G.N. Slinn, pp. 1131 43. Amsterdam Elsevier. 

Plutonium aerosols due to nuclear weapons testing or nuclear reactor accidents... 

Plutonium aerosols can be formed in various ways, including (a) oxidation or volatilisation of Pu metal, (b) oxidation or volatilisation of irradiated U or UO2, (c) droplet dispersion from aqueous solutions or suspensions of Pu, and (d) resuspension of soil or dust which has become contaminated with Pu. The particle size of Pu-aerosols is very variable, depending on the mode of formation. 

Elder, J.C., Gonzales, M., Ettinger, H.J. (1974). Plutonium aerosol size characteristics. Health Phys. 27, 45-53. El-Hussein, A., Ahmed, A.A. (1995). Unattached fraction and size distribution of aerosol-attached radon prrgeny in... 

Plutonium solutions that have a low activity (<3.7 x 10 Bq (1 mCi) or 10 mg of Pu) and that do not produce aerosols can be handled safely by a trained radiochemist in a laboratory fume hood with face velocity 125—150 linear feet per minute (38—45 m/min). Larger amounts of solutions, solutions that may produce aerosols, and plutonium compounds that are not air-sensitive are handled in glove boxes that ate maintained at a slight negative pressure, ca 0.1 kPa (0.001 atm, more precisely measured as 1.0—1.2 cm (0.35—0.50 in.) differential pressure on a water column) with respect to the surrounding laboratory pressure (176,179—181). This air is exhausted through high efficiency particulate (HEPA) filters. 

Okabayashi H. 1980. Differential movement of plutonium and americium in lungs of rats following the inhalation of submicron plutonium nitrate aerosol. J Radiat Res 21 111-117. 

Stanley JA, Edison AF, Mewhinney JA, et al. 1978. Inhalation toxicology of industrial plutonium and uranium oxide aerosols II. Deposition, retention and dosimetry. Health Phys 35(6) 888. 

Stanley JA, Edison AF, Mewhinney JA. 1982. Distribution, retention and dosimetry of plutonium and americium in the rat, dog and monkey after inhalation of an industrial-mixed uranium and plutonium oxide aerosol. Health Phys 43(4) 521-530. 

Taya A, Hotz G, Seidel A. 1986. Biochemical and electron microscopic studies on binding and transport of americium and plutonium hydroxide polymers in bovine alveolar macrophages and rat lungs. J Aerosol Sci 17(3) 370-375. 

Americans used TNT, RDX and HMX for nuclear weapons in the initial years but their use posed additional hazard of aerosolized-plutonium dispersal. The scattering of this long-lived isotope poses a great danger to human life as well as... 

On a comparative basis, Pu, Am and Cm tend to be assimilated from the G.I. tract into the internal body in the following order Pu < Am < Cm (Figure 3). When Pu-nitrate is inhaled in aerosol form by dogs (27), daughter Am-241 tends to be transported more from lung and lymph nodes to liver than does plutonium (Fig. 3). Another example of potential Am enrichment is that when the rumen contents of fistulated cattle grazing on the Nevada Nuclear Test Site were leached with simulated gastric fluids,... 

The particle size of a fission aerosol, and the distribution of fission products between particulate and vapour phases, depends on the mechanism of release to the atmosphere. In a weapons explosion, some physicochemical fractionation of radionuclides may occur, particularly if the explosion is near the ground. Everything in the vicinity is vapourised by the heat of the explosion, but within less than a minute the fireball cools to a temperature in the range 1000-2000°C, and refractory materials such as metal oxides and silicates condense to form particles (Glasstone Dolan, 1977). Refractory fission products, and plutonium, are incorporated in these particles. 

Plutonium is so toxic that processing and fabrication are always done in sealed cells or glove boxes, but accidental dispersions of aerosol occur from time to time. Following combustion of Pu metal chips in a production area at Rocky Flats, Colorado, in 1964, airborne contamination was widespread. Alpha tracks from individual particles caught on membrane filters were detected on nuclear film, and the Pu content, and hence the particle size, was deduced (Fig. 5.2, curve E). The activity median diameter was 0.3 /urn (Mann Kirchner, 1967). The same method, used during normal operations in a production area at Los Alamos, gave activity median diameters in the range 0.15 to 0.65 /urn (Moss et al., 1961). However, when a spill occurred, followed by clean-up operations, the Pu particles were found to be associated with inert dust particles of mass median diameter 7 /urn. 

Two plutonium weapons fell from a US aircraft after a collision over Palomares, Spain, in 1966 and chemical explosions occurred on impact with the ground. The plutonium was converted into a fine oxide aerosol and spread by wind (Harley, 1980). Soil samples were analysed, and... 

The seas are a source of aerosol (i.e. small particles), which transfer to the atmosphere. These will subsequently deposit, possibly after chemical modification, either back in the sea (the major part) or on land (the minor part). Marine aerosol comprises largely unfractionated seawater, but may also contain some abnormally enriched components. One example of abnormal enrichment occurs on the eastern coast of the Irish Sea. Liquid effluents from the Sellafield nuclear fuel reprocessing plant in west Cumbria are discharged into the Irish Sea by pipeline. At one time, permitted discharges were appreciable and as a result radioisotopes such as Cs and several isotopes of plutonium have accumulated in the waters and sediments of the Irish Sea. A small fraction of these radioisotopes were carried back inland in marine aerosol and deposited predominantly in the coastal zone. While the abundance of Cs in marine aerosol was refiective only of its abundance in seawater (an enrichment factor - see Chapter 4 - of close to unity), plutonium was abnormally enriched due to selective incorporation of small suspended sediment particles in the aerosol. This has manifested itself in enrichment of plutonium in soils on the west Cumbrian coast,shown as contours of 239+240p deposition (pCi cm ) to soil in Figure 3. 

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