Krypton-85 in the atmosphere 1950-1977: a data review
Abstract
For over 20 years the radioactive noble gas 85Kr, the product of nuclear industry, has been released to the environment mainly from nuclear fuel reprocessing plants. Owing to its relatively long half-life T(1/2 = 10.76 y) and the absence of other appreciable sinks, a cumulative buildup of 85Kr in the atmosphere is observed. The mean 85Kr surface air activity in the northern hemisphere has increased from about 20 dpm/mmol Kr in 1950 to about 750 dpm/mmol Kr in 1977. In recent years, a substantial slow-down of the 85Kr emission rate to the atmosphere has been observed. The published data indicate rather good mixing of 85Kr in the northern hemisphere, but a gradient is observed in the southern hemisphere due to the fact that all nuclear fuel reprocessing plants are situated in the northern hemisphere and due to poor mixing of the atmosphere in the meridional direction.
This paper summarizes nearly all of the data on 85Kr activity in the atmosphere published up to the middle of 1978. The spatio-temporal distribution of 85Kr atmospheric activity is discussed. Some forecasts of future 85Kr concentration in the atmosphere and its possible ecological consequences are also presented.- Publication:
-
Environment International
- Pub Date:
- 1979
- DOI:
- 10.1016/0160-4120(79)90071-0
- Bibcode:
- 1979EnInt...2..139R