Atmospheric Burnup of a Plutonium-238 Generator

Abstract

The stratospheric inventory of the plutonium-238 resulting from the disintegration of a nuclear auxiliary power generator (SNAP-9A) in early 1966 accounts for essentially all the plutonium present in the original generator that reentered the atmosphere. Consequently, the pyrophoric (238)Pu must have completely burned up during reentry and ablated into small particles. The arithmetic mean of the distribution of the (238)Pu particle size was estimated to be 10 millimicrons, which confirms this conclusion.

Annual Deposition of Sr-90, Cs-137 and Pu-239, 240 from the 1961-1980 Nuclear Explosions: A Simple Model

“…The total stratospheric inventory of excess Pu-238 in the Northern Hemisphere can be evaluated from the A(T0) value. The total Northern Hemisphere stratospheric inventory of excess Pu-238 is calculated to be about 2kCi which is also in agreement with the value of 3kCi obtained by integrating the isoline of the stratospheric Pu-238 concentrations from the atmospheric burnup of SNAP-9A observed in 1966 (Krey, 1967). This suggests that for the.…”

“…The values of f0 and f1 reflect that most of the excess Pu-238 were initially present in the upper stratospheric compartment. This result suggests that the inter- hemispheric exchange of radioactive debris, which was injected into the lower mesosphere and upper stratosphere with the burnup of the reentered satellite (Krey, 1967), occurs not in the lower stratosphere but in the upper stratosphere and/or lower mesosphere. In this connection, Kida (1985) has shown a strong meridional flow form the summer pole toward the winter pole at the mesosphere.…”

“…In the case of the high-altitude injection, the velocity of the downward transport of fine particles in the upper stratosphere plays an important role to determine the stratospheric residence time. In this connection, after the SNAP-9A satellite failure in 1964, Krey (1967) estimated the downward velocity of 0.09cm/s as an averaged value from 35km to 25km and the slower downward velocity of about 0.03cm/s from 25km to 14km in the stratosphere.…”

The origin of plutonium in the atmosphere.

“…It appeared as if the recent volcanic erup cally powered satellite SNAP-9A (Systems for tions may have played an important role in alter Nuclear Auxiliary Power) have been studied ing the stratospheric inventory of plutonium during the past two decades by several investi during the past few years. Meanwhile, a number gators (Harley, 1964;Krey, 1967; Mamuro and of reports on the occurrence of `natural' pluto Matsunami) 1969; Debartoli and Gaglione, 1969; nium in volcanic samples have appeared in the Miyake et al, 1970;Hardy et al, 1973;Gavini literature. Meier et al (1974), for example, and Kuroda, 1977;Holloway and Hayes, 1982; reported Pu/U ratios of up to 10`' atom/atom Katsuragi et al, 1982).…”

Plutonium isotopes in the atmosphere.

“…A 100-liter sample 9A (Systems for Nuclear Auxiliary Power) of rain was taken for each plutonium analysis. failed to reach orbital velocity over the Indian The chemistry consisted of co-precipitation of Ocean (HARLEY, 1964;KREY, 1967; BORTOLI, plutonium with lanthanum carrier as fluorides and GAGLIONE, 1969; MAMURO and MATSUNAMI, and extraction with 5.6 percent (w/v) -TTA in 1969; MIYAKE et al, 1968MIYAKE et al, , 1970MIYAKE et al, , 1975; HARDY xylene. Plutonium was electroplated on a stain et al, 1973).…”