Baklanova Yu V, Umarov M A, Dyuisembaeva M T, Lukashenko S N
Institute of Radiation Safety and Ecology of the NNC RK, Kurchatov, Kazakhstan.
Institute of Radiation Safety and Ecology of the NNC RK, Kurchatov, Kazakhstan.
J Environ Radioact. 2020 Mar;213:106103. doi: 10.1016/j.jenvrad.2019.106103. Epub 2019 Nov 18.
The paper presents the results of Sr/Cs isotopic ratios in the soil surface layer in the venues of surface and atmospheric nuclear tests at the territory of the «Experimental Field » site of the Semipalatinsk Test Site. One of the main factors in the radiation impact of a nuclear explosion on the environment is the decay of fission products. The determination of Cs activity in soil is carried out by accurate, rapid and sufficiently cheap gamma-spectrometric method, while the existing methods of determining Sr activity are quite problematic: they either have sufficiently high detection limits or are time-consuming. As an alternative method, Sr activity can be determined using its correlation dependence with Cs activity. According to the literature, each test has its own fission product ratio, depending on the nuclear charge. As a result of the conducted research it was revealed that one epicenter is located at the technical site P-1, the ratio of Sr/Cs is equal to 4,8; at the technical site P-3 - 2 epicenters, the ratio of Sr/Cs is equal to 0,8 and 0,9; at the technical site P-5 - 6 epicenters, the ratio of Sr/Cs is in the range of 0,9-2,1; at the technical sites P-2, P-7 - 19 epicenters, the ratio of Sr/Cs is in the range of 0,6-2,1. It is assumed that the differences in the value of fission product ratios are due to different types and capacities of nuclear charges, as well as different explosion altitudes. The obtained ratios allow to calculate Sr by Cs activity in soil of the epicentral zones at the territory of the «Experimental Field » testing site by the computational method.
本文介绍了塞米巴拉金斯克试验场“试验场”场地地表和大气核试验场地表层土壤中锶/铯同位素比值的结果。核爆炸对环境辐射影响的主要因素之一是裂变产物的衰变。土壤中铯活度的测定采用准确、快速且成本足够低的伽马能谱法，而现有的测定锶活度的方法存在很大问题：它们要么检测限足够高，要么耗时。作为一种替代方法，可以利用锶活度与铯活度的相关关系来测定锶活度。根据文献，每次试验都有其自身的裂变产物比值，这取决于核电荷。所进行的研究结果表明，一个震中位于技术场地P-1，锶/铯比值等于4.8；在技术场地P-3有2个震中，锶/铯比值分别等于0.8和0.9；在技术场地P-5有6个震中，锶/铯比值在0.9 - 2.1范围内；在技术场地P-2、P-7有19个震中，锶/铯比值在0.6 - 2.1范围内。据推测，裂变产物比值的差异是由于核电荷的类型和容量不同以及爆炸高度不同所致。所获得的比值使得能够通过计算方法根据“试验场”试验场地震中区土壤中的铯活度来计算锶活度。
