Environmental Radioactivity Problem around the Former Soviet Union's Semipalatinsk Nuclear Test Site

本文是关于我们对塞米巴拉金斯克核试验场境内和境外的剩余放射性、钚同位素和铯的调查报告<137>。在连接库尔恰托夫市、苏联第一次核试验归零地、Balapan、Degelen山和Salzhal定居点的道路沿线约沿着30个地点采集了试验场内的土壤样本。此外，在试验场之外，在大约20个地点，包括一些定居点（Mostik、Dolon、Tchagan等），对土壤进行了取样，在从塞米巴拉金斯克市到库尔恰托夫市和北Korosteli定居点的道路沿线，沿着的森林和牧场。用<137><238><240><239>γ能谱法、放化分离-α能谱法和/或ICP-MS法分别测定了土壤中长寿命放射性核素^ Cs、^ Pu和^&lt;239，240&gt;Pu的污染水平及^ Pu/^ Pu的原子比。结果表明，<137>除了世贸中心遗址和巴拉潘附近的地区外，^ Cs处于典型的环境水平之内，但在我们访问的所有地区，^&lt;239，240&gt;Pu都被武器级钚污染。从土壤中钚的逐步浸出来看，大多数样品中总^&lt;239，240&gt;钚的50-80%紧密结合在爆炸时可能已熔化的土壤成分中。

This paper is a report on our survey of residual radioactivity, Pu isotopes and ^<137>Cs, within and without the territory of the Semipalatinsk nuclear test site. Soil samples within the test site were collected at approximately' 30 sites along the roads connecting Kurchatov City, ground zero for the first USSR nuclear test, Balapan, Degelen Mountain and Salzhal settlement. Furthermore, outside the test site, the soil was sampled at about 20 sites, including some settlements (Mostik, Dolon, Tchagan, etc.), forest and pasture areas, along the roads from Semipalatinsk City to Kurchatov City and north Korosteli settlement. The contamination levels of long-lived radionuclides, ^<137>Cs, ^<238>Pu and ^<239,240>Pu as well as ^<240>Pu/^<239>Pu atomic ratio in the soil were determined by non-destructive gamma-spectrometric method and radiochemical sepatation followed by alpha -spectrometic and/or ICP-MS methods, respectively. The resutls showed that although ^<137>Cs was within typical environmental levels except for an areas near ground zero and Balapan, ^<239,240>Pu was elevated levels contaminated with weapons-grade plutonium in all area we visited . From the stepwise leaching of Pu from the soil, 50-80% of total ^<239, 240>Pu in most samples was found to be tightly incorporated into the soil components which might have been melted at time of detonation.