SPECIAL PARTICULATE ANALYSIS.

Several thousand plutonium-bearing particles, representing over 200 physical samples, from Operation Roller Coaster were examined. Cascade impactors, filters, and deposition collectors were included. Nuclear track autoradiography and optical microscopy measurements of particle size, shape, color and estimated activity were made for particles as small as 0.6 micron projected area diameter. Spherical particles as small as 0.05 micron diameter were measured by electron microscopy and the data compared with nuclear track counts for the same sample. Estimates of the density of particles were made from observation of Casella MK II impactor stages. Phosphor intensification autoradiography was applied to over 500 samples. No calibration to derive particle size was made due to the inhomogeneous particle composition. Single particle larger than 14 microns were isolated for alpha counting, radiochemical analysis, X-ray diffraction, and electron microprobe analysis under other projects. Calculation of alpha self-absorption factor, microgram Umicrogram Pu, and particle density were obtained from the data. A wide range of particle compositions was encountered. Evidence that a few particles contained unreacted Pu was found. Most particles contained less than 20 percent plutonium. Author