Atmospheric injections of nuclear debris: Strontium 89 and 90 from Chinese weapons tests

Abstract

The concentrations of 89Sr and 90Sr in a total of 455 samples of individual rain and snow collected at Fayetteville (36°N, 94°W), Arkansas, were determined radiochemically during the period between April 1973 and June 1981. Nine atmospheric nuclear tests were conducted by the government of China at Lop Nor (40°N, 90°W) during the period 1973–1981. The Chinese nuclear tests of June 27, 1973 (3‐megaton, the 15th test); June 17, 1974 (1–2 megaton, the 16th); January 23, 1976 (reported to have been a low‐yield device, the 18th); and November 17, 1976 (4‐megaton, the 21st) injected the bulk of the nuclear debris into the stratosphere. The values of mean residence times ranging from 7 to 20 days obtained after the 19th, 22nd, 23rd, and 24th Chinese tests were similar to those reported earlier for the mean residence time of nuclear debris injected into the troposhere. The cycling effect of the nuclear debris was observed after the 22nd Chinese test of September 17, 1977, and the 25th Chinese test of October 16, 1980.

Atmospheric injections of polonium-210 from the recent volcanic eruptions.

“…The amount of excess concentration of 210Po in air varies seasonally 210Po obtained was then compared with the and from one geographical location to another total amount of 90Sr released by the 16 October in a very complicated manner; and (c) there 1980 Chinese nuclear explosion of a 0.2 to 1 are a number of sources other than the vol megaton device, which was similarly obtained canoes which may contribute to the production from the analyses of the concentrations of 90Sr of excess 210Po in the atmosphere. For example, in the entire series of individual rain and snow Turekian et al (1974) reported that an excess samples (Kuroda et al, 1984;Burchfield et of 210Po over 210Pb is produced by plankton in al., 1983;Burchfield et al, 1982). the seas and is then transported from the surface The results obtained by Kuroda et alL waters to the atmosphere.…”

Beryllium-7 deposition at Fayetteville, Arkansas, and excess polonium-210 from the 1980 eruption of Mount St. Helens.

“…It is worthy of note here, however, that Turekian et al (1983) have recently reported the values of 17.1 (dpm/cm2/y) at Bermuda (33'N) and 22.7 (dpm/cm2/y) at New Haven (41°N), Connecticut. The 90 Sr and 210Po data were taken from the reports of Burchfield et al (1982), Burchfield and Kuroda (1983), and Kuroda et al (1984). A marked increase in the 90 Sr/' Be ratio in rain observed during the first half of 1981 is attributable to the 25th Chinese nuclear explosion of 16 October 1980 (Burchfield et al, 1982;Burchfield and Kuroda, 1983).…”

“…The 90 Sr and 210Po data were taken from the reports of Burchfield et al (1982), Burchfield and Kuroda (1983), and Kuroda et al (1984). A marked increase in the 90 Sr/' Be ratio in rain observed during the first half of 1981 is attributable to the 25th Chinese nuclear explosion of 16 October 1980 (Burchfield et al, 1982;Burchfield and Kuroda, 1983). Note that the South African incident of 22 September 1979, in which a small nuclear weapon was reported to have been tested in the southern hemisphere, had no significant effect on the 90 Sr concentrations in rain collected at Fayetteville, Arkansas.…”

Polonium-210 fallout from the 1980 eruption of Mount St. Helens and the mystery cloud of 1982.

“…The amount of excess 210Po obtained was then compared with the total amount of 90 Sr released by the 16 October 1980 Chinese nuclear explosion of a 0.2 to 1 megaton nuclear device (BURCHFIELD et al, 1982, BURCHFIELD andKURODA, 1983), which was similarly obtained from the analyses of the concentrations of 90 Sr in the entire series of rain and snow samples.…”