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Radioactive contamination around the former Soviet Union's Semipalatinsk nuclear test site and estimation of internal radiation dose for people

前苏联塞米巴拉金斯克核试验场周围放射性污染及人体体内辐射剂量估算

基本信息

批准号：
16404004
负责人：
YAMAMOTO Masayoshi
金额：
$ 7.23万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

Nuclear weapon tests by the former USSR at the Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan caused a vast amount of radioactive contamination around the test site. Dolon village is known as one of the most contaminated villages by radioactive fallout around SNTS. Calculated external gamma-ray dose in air by model ranged from 1 to 2 Gy, while TL measurement of a brick sample n Dolon taken from a church was close to about 0.5 Gy. Thus, In Dolon village, some discrepancies in the dose estimation for the village among investigators were pointed out. In relation to the effort to reconstract the radiation dose in Dolon village, the width and center-axis location of the radioactive plume were investigated based on the soil contamination data around Dolon and the nearby villages. Additional soil contamination data around Dolon were obtained during the period of this study. As a result, the plotted distribution formed a peak-like shape for Cs-137 and Pu-239,240. The center part of the plume passed over the residential area of Dolon with one sigma value of 1.5 km. Finally, 0.50 Gy of absorbed dose in air was derived as our tentative estimate for 1-year cumulative external dose in Dolon due to local fallout from the first USSR test in 1949.Parallel to the above works, to evaluate the present Pu and Cs-137 levels in the general population living near the SNTS and to estimate the associated alpha doses, Pu-239,240 and U isotopes in bone samples from more than 70 autopsies of residents were measured. By assuming that average concentration of Pu-239,240 in bone samples is the value at 45 years after instantaneous inhalation in 1955,the initial total and the effective dose for 45 years were estimated as 10 Bq and 1.2 mSv, respectively. The annual intake of total U and its effective dose for 60 years were estimated as 30 Bq for adult and 0.1 mSv, respectively, for chronic ingestion.

前苏联在哈萨克斯坦塞米巴拉金斯克核试验场进行的核武器试验在试验场周围造成了大量的放射性污染。Dolon村是SNTS周围受放射性沉降物污染最严重的村庄之一。通过模型计算的空气中外部伽马射线剂量范围为1 ~ 2 Gy，而从教堂中采集的一块砖样品的辐射强度测量值接近0.5 Gy。因此，在Dolon村，调查人员对该村的剂量估计存在一些差异。为了重建Dolon村的辐射剂量，根据Dolon村周围和附近村庄的土壤污染数据，对放射性羽流的宽度和中轴线位置进行了调查。在本研究期间，获得了Dolon周围的其他土壤污染数据。结果，Cs-137和Pu-239,240的分布图呈峰状分布。羽流中心部分经过Dolon居民区，sigma值为1.5 km。最后，我们对1949年苏联第一次试验产生的局部放射性尘降物在Dolon造成的1年累积外剂量进行了初步估计，得出空气中吸收剂量为0.50 Gy。在上述工作的同时，为了评估居住在SNTS附近的一般人群中目前的Pu和Cs-137水平并估计相关的α剂量，对70多名居民尸体解剖的骨骼样本中的Pu-239,240和U同位素进行了测量。假设骨样品中Pu-239,240的平均浓度为1955年瞬时吸入45年后的值，则估计45年的初始总剂量为10 Bq，有效剂量为1.2 mSv。据估计，60年的成人年总U摄入量和有效剂量分别为30 Bq和0.1 mSv。