【摘要】 参照地震发生频率、地块稳定特性等地质环境因素,结合水中的同位素及水化学特征分析,对塔里木盆地东部地区的核试验场地与北山地区作为高放废物处置场的预选址的安全性与合理性加以对比论述。研究结果显示,北山地区30 km以下的下地壳中存在着高导低速层,附近地区历史上曾发生过多次大地震,是一个相对不稳定地块。北山的地下水经分析并非是最初认定的"古水",也不是来自当地降水,而是祁连山的降水通过深大断裂带补给的,北山附近的花海地区自流井的流量就达到了106 m3/a。北山地区的深层地下水为淡水,径流速度较快,下游为生态与环境的重点保护区额济纳盆地,因此会不利于将其作为高放废物处置场的选址。相比较而言,塔里木盆地东部地区历史上从未发生过较大的地震,地壳层中不存在高导低速层,同位素数据显示其地下水主要来自当地的降雨和河流的入渗补给,地下水中总溶解固体随着深度的增加而增加,地下水的循环周期较长,地下径流的最终排泄区是罗布泊荒漠戈壁地区,而且塔里木盆地东部军事禁区存在面积超过3 000 km2的花岗岩。因此在已经受到污染的核试验地区修建永久性处置高放废物要比北山地区更为安全,即使未来发生最不利的污染等事件也可以将对环境与生态的破坏降到最低。更多还原

【Abstract】 Security and reliability for choosing a disposal location of high-level nuclear waste have been discussed.Eastern Tarim Basin and Beishan area are compared by terms of some geological condition factors such as earthquake occurrence frequencies and block stability together with analysis of isotopic and hydrochemical parameters in the water samples.The results show that a high-conductivity and low-velocity layer of the earth′s crust is detected in the Beishan area,with the depth of more than 30 km.The basal lamina here is instable,accompanying major earthquakes frequently occurred in the past.Researches show that groundwater in Beishan area is neither sourced from "palaeo-water"nor from local precipitation,but from the precipitation in Qilian Mountain through large deep fault zones.Artesian wells with the volumes of 106 m3 per year are found in Huahai area nearby the Beishan area.Moreover,deep groundwater in this region belongs to fresh water.Runoff velocity is fast.If Beishan area was chosen as the disposal location of high-level nuclear waste,ecological environment of the lower reach,namely,Ejina Basin,would be destroyed.In contrast,eastern Tarim Basin belongs to stable block.High-conductivity and low-velocity layers are not found in this area.Major earthquakes did not occur in geological period.Groundwater originates from infiltrated supply of rivers and lakes,with the total dissolved solids(TDS) values increase with depth.The circulation period of the groundwater is relative a long time.The runoff underneath eventually flows to the Lop Nur gobi area.In addition,there covers granite with the area larger than 3 000 km2 underneath the earth surface of military base in eastern Tarim Basin.As a result,it seems to be more secure and reliable if choosing the polluted nuclear tests base station in eastern Tarim Basin as permanent disposal location than Beishan area.The destroy degree to ecological environment could be dropped to lowness if the disadvantageous events happen in the future.更多还原