NOTES ON THE DEPOSITION OF FALLOUT IN RELATION TO TOPOGRAPHY AND LOCAL METEOROLOGICAL CONDITIONS

摘要

This study was made as part of an effort to collect radioactive effluents released during the test operation of a Kiwi, reactor (Kiwi B-la) on December 7, 1961. Granular fallout collectors and cheesecloth aerosol collectors were percolated along- roads approximating arcs of 5, 16, and 37 miles from the reactor test cell at the Nevada Test Site. Each of these arcs crossed successively lower and wider parts of a gently sloping valley. A last-minute shift in wind direction carried the effluent cloud away from the percolated sampling devices. Apparently, the cloud was trapped until nightfall in an inversion layer from 2000° to 3500' feet above the surface.nDuring the night following the reactor test, Tropospheric or stratospheric fallout probably derived from nuclear detonations in the U.S.S.R. (but no short-lived fission products) were deposited on the above-mentioned sampling devices. Due to the influence of shallow-valley inversion and cold air drainage, the pattern of this deposition was closely related to the local topography.