Uranium, plutonium, and thorium isotopes in the atmosphere and the lithosphere

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6467561

Essien, I O

Concentration of /sup 238/U in rain and snow collected at Fayetteville (36/sup 0/N, 94/sup 0/W), Arkansas, showed a marked increase during the summer months of 1980, while Mount St. Helens remained active. This observed increase of /sup 238/U can be explained as due to the fallout of natural uranium from the eruption of Mount St. Helens. Large increases in the concentration of thorium isotopes detected in rain and snow samples during the last months of 1982 and early months of 1983 probably originated from the eruption of El Chichon volcano, which occurred on 28 March 1982. About 450 Ci of /sup 232/Th is estimated to have been injected into the atmosphere by this eruption. Isotopic anomalies were observed in atmospheric samples such as rain and snow. These anomalies can be attributed to various natural as well as man-made sources: nuclear weapon tests, nuclear accidents involving the burn-up of nuclear powered satellites, and volcanic eruptions. The variation of /sup 234/U//sup 238/U ratios in radioactive minerals when leached with nitric acid were also noticed and this variation, while /sup 235/U//sup 238/U remained fairly constant, can be explained in terms of the ..cap alpha..-recoil effect and changes in oxidation state of uranium. Difference found in /sup 239/Pu//sup 238/U ratios in terrestrial samples and uranium minerals can be explained as due to fallout contamination.

• Research Organization: Arkansas Univ., Fayetteville (USA)
• OSTI ID: 6467561
• Country of Publication: United States
• Language: English

Related Subjects

500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
580202 -- Geophysics-- Volcanology-- (1980-1989)
ACTINIDE ISOTOPES
AIR POLLUTION MONITORING
ARKANSAS
EXPLOSIONS
FALLOUT
FEDERAL REGION VI
HYDROGEN COMPOUNDS
ISOTOPES
NORTH AMERICA
NUCLEAR EXPLOSIONS
OXYGEN COMPOUNDS
PLUTONIUM ISOTOPES
RAIN WATER
THORIUM ISOTOPES
URANIUM ISOTOPES
USA
VOLCANOES
WATER