Uranium and plutonium isotopes in the atmosphere

Abstract

Uranium 234 and 235 were found to be highly enriched relative to uranium 238 in several rain samples collected at Fayetteville, Arkansas, during the months of April and May 1980. The anomalous uranium appears to have originated from the Soviet satellite Cosmos‐954, which fell over Canada on January 24, 1978. The uranium fallout occurred just about the time Mount St. Helens erupted on May 18, 1980. The concentration of 238U in rain increased markedly after the eruption of Mount St. Helens, and it appeared as if a large quantity of natural uranium was injected into the atmosphere by the volcanic eruption. The pattern of variation of the concentrations of uranium in rain after the eruption of Mount St. Helens was found to be similar to that of plutonium isotopes.

Alpha-Recoil Effects of Uranium Isotopes in Radioactive Minerals

“…The radiochemical procedures employed for the separation and purification of uranium were essentially the same as those described by SAKURAGI et al [13] and also by SHENG and KURODA [12].…”

Plutonium anomaly in nature.

“…Results from the measurement of plutonium and uranium isotopes in rain and snow samples in our laboratory for the period between March 1980 through May 1981 have already been published (SAKURAGI et al, 1983). Uranium 234 and U-235 were found to be highly enriched relative to U-238 in several rain samples col lected at Fayetteville (36°N, 94°W), Arkansas, during the months of April and May of 1980.…”

“…The control experiments carried out in our laboratory by one of us (1.0. ESSIEN) have already been described (see SAKURAGI et al, 1983).…”

Variation of the Isotopic Composition of Uranium in the Atmosphere

“…It is well known that there are two kinds of radioactive fallout: tropospheric and stratospheric. The effects from the former are immediate, while the latter is characterized by its delayed action and the effects sometimes show up two to three years later at about the time the events had become almost forgotten [1], For example, the fallout of 89 Sr (half-life, 50.4-days) from the 7 February 1983 burn-up of the Soviet satellite Cosmos-1402 was detected in rain samples collected at Fayetteville (36°N, 94°W), Arkansas, within two weeks and lasted for about sixteen weeks [2]. THOMAS and MARTIN [3], on the other hand, have detected the radioactive plume from the 26 April 1986 Chernobyl accident over Paris on 29 April 1986 and reported that the maximum concentrations of 137 Cs over a period of three days were 400 times greater than during the world-wide fallout of 1963.…”