共查询到19条相似文献，搜索用时 765 毫秒
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高放废物地质处置库选址要求围岩完整稳定,它与岩体深部地质结构密切相关,因此是场址评价中必须考虑的因素.在高放废物储库选址新区内蒙阿拉善塔木素岩体,采用可控源音频大地电磁法进行了剖面探测.分析了典型测深曲线,区分了地质构造和完整围岩的响应特征;针对高放废物预选场址的特点,对原始数据进行了处理;结合已有地质、钻井及测井资料完成了解释;结果表明,利用可控源音频大地电磁法有效地查明了该地岩体内部结构,该岩体存在裂隙和破碎,完整性欠佳. 相似文献
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《应用地球物理》2019,(3)
通常基于不同稳定泛函的反演对目标体边界的刻画存在着差异,尤其对复杂地质构造。为此,本文提出了面向电性边界识别的基于不同稳定泛函的极值边界反演算法。首先选择最平滑、最小支撑两种稳定泛函研究自适应正则化反演算法对不同稳定泛函的适用性,然后通过引入极值边界反演算法,研发基于不同稳定泛函的电性边界识别技术。研究结果表明:自适应正则化反演方法适用于不同的稳定泛函,而且对初始模型的依赖性较低;极值边界反演算法得到的光滑和聚焦上下界并集的比值可以作为划分电性界面的有效依据。在此基础上,本文以内蒙古塔木素地区高放废物粘土岩处置库场址预选为例,将本文提出的反演算法应用于该区的大地电磁测深(MT)数据反演,利用光滑反演了解区域构造,利用聚焦反演了解局部细节,并结合地表地质和钻孔资料,基于地下地质体的电性边界的识别,圈定了目标层的厚度,得到的目标层的厚度满足高放废物处置库选址的要求。 相似文献
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甘肃北山花岗岩中填隙黏土对U(Ⅵ), 234U(Ⅵ)和238U(Ⅵ)的吸附性状: 应用于中国高放废物处置库选址 总被引：2，自引：0，他引：2
报道中国甘肃北山地区1号二长花岗岩岩体中原状(未提纯)填隙黏土吸附U(Ⅵ), 234U(Ⅵ)和238U(Ⅵ)的实验结果. 该二长花岗岩体是中国高放废物(HLW)处置库的预选库址之一. 实验结果表明, 在近中性条件下, U(Ⅵ)的吸附率最高(占总量的92%), Kd (分配系数)=1226 mL/g. 填隙黏土对放射性元素具有大的吸附容量, 是高放废物深地质处置库主岩必备性质之一. 在本次研究的实验条件下未发现该类黏土对放射性核素234U(Ⅵ), 238U(Ⅵ)的选择性吸附现象. 最后, 用表面络合模型(SCM)模拟计算了该类原状黏土对U(Ⅵ)的吸附特征. 相似文献
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重大工程场址断层活动的研究 总被引：1，自引：0，他引：1
研究重大工程场址断层活动（特别是断层的最后一次活动）对于工程的设计和建设十分必要．许多工程选址在基岩裸露区，缺乏能标明断层活动特征的新地层。为了在这些地区顺利地开展工作，笔者探索了一条新的途径，即利用变形岩石显微构造分析方法和多种测试技术对断层带物质进行综合分析测试，提取留存其中的有关断层活动规律的信息．本文论证了该方法的理论依据和可行性，并着重总结了应用该法在几个重大水电工程场址内进行断裂活动研究的成果．这些成果为工程设计人员提供了可靠的工程地质依据，也证明了该研究途径的有效性和实用性． 相似文献
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新疆库尔勒市北山山前断裂(简称北山断裂)展布于库尔勒北博洛霍坦山(即北山)南麓,也称博洛霍坦山前断裂,历来被视为库尔勒—辛格尔深大断裂的一支,属于北轮台——秋里塔格断裂的一段。 北山断裂系一条新活动断裂,运动性质为左旋走滑兼逆冲。该断裂穿过库尔勒市区北侧,并遗留有断层陡坎、新断错地貌以及丰富的喷水冒砂等古地震事件遗迹。多处断层露头显示出 相似文献
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对于高放射性核废物地下处置库设计而言,宿主岩石的热力学特性的研究受到人们广泛地注意.花岗岩在热冲击的高温氧化环境下变成了一个风化的含大量微缺陷的材料,对于其破裂面的微观特征观察 相似文献
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拟建中的某工程场址经工程地质勘探和基础开挖发现一规模较大的北西向断层。本文通过对该断层的地貌形态、断层面宏观结构、断层带内物质的显微构造分析以及第四纪地层的^14C测年，对该断层进行了活动性鉴定，并提出了工程设计应注意的问题。 相似文献
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根据焦家坪地震区深峡谷两侧的密集台网观测结果,分析了峡谷两侧的振动特征。对修建在复杂地形条件下的大型水电工程场址地震微小区划问题进行了初步研究。并对断层带上的振幅异常作了分析 相似文献
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MIN Maozhong LUO Xingzhang WANG Ju JIN Yuanxin & WANG Rucheng . Department of Earth Sciences State Key Laboratory of Mineral Deposit Research Nanjing University Nanjing China . Center of Materials Analysis Nanjing University Nanjing China . Department of Environmental Science Engineering Nanjing University Nanjing China . Beijing Geology Institute Nuclear Industry Beijing China 《中国科学D辑(英文版)》2005,48(10)
Knowing the transport of uranium and radionu-clides through the environment is important for as-sessing the risk posed by long-term disposal of rad-waste. Granitic rocks have been selected as a host-rock type for the first high-level radwaste repository in China. According to the Chinese High-level Rad-waste Management Program, high-level radwaste (HLW) will be buried at 800―1000 m depth in a granitic pluton in Northwest China and, specifically, in the A granitic complex of Beishan area,… 相似文献
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Models that calculate the probability that a new volcano or a dike from a nearby eruption will intersect the footprint of the proposed high-level nuclear waste repository are generalized based on a conceptual model developed for the space transportation industry. The proposed hazard area, defined such that every new eruption that occurs there will disrupt the repository, plays a fundamental role in developing probability models. This hazard area is used not only to hedge the uncertainties in predicting patterns of future volcanic activity, but also to account for the characteristics of a new eruption during the post-closure performance period of an underground geologic repository. The paper discusses the advantages of probability comparisons, capabilities of conservativeness measurements and expert-elicitation on model parameters, and the implications to the proposed repository.Paper funded by a contract from the Agency for Nuclear Projects, State of Nevada, USA. 相似文献
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Uncertainty analysis of radioactive nuclide transport for one-dimensional single fracture has been studied. First order differential analysis is applied to introduce analytical form of output expectation and variance for contaminant transport equation, by regarding uncertainty of dispersion coefficient and retardation factor. Breakthrough curve of dimensionless concentration is demonstrated by taking I-129 as radioactive nuclide in fracture transport. It is possible to pick up critical ranges in spatial and temporal domain from the output variance. From the viewpoint of preliminary performance assessment for nuclear waste disposal the parameter importance in such system can be substantially measured in the site characterization in future. 相似文献
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Chih-Hsiang Ho 《Bulletin of Volcanology》2010,72(2):205-219
The post-12-Ma volcanism at Yucca Mountain (YM), Nevada, a potential site for an underground geologic repository of high-level
radioactive waste in the USA, is assumed to follow a Poisson process and is characterized by a sequence of empirical recurrence
rate time series. The last ten time series are used as a prediction set to check the predictive ability of the candidate model
produced by a training sample using autoregressive integrated moving average modeling techniques. The model is used to forecast
future recurrence rates that, in turn, are used to develop a continuous mean function of the volcanic process, which is not
only required to evaluate the probability of site disruption by volcanic activity but accommodates a long period of compliance.
At the model validation stage, our candidate model forecasts a mean number of 6.196 eruptions for the prediction set which
accounts for seven volcanic events of the 33 post-12-Ma eruptions at the YM site. For a full-scaled forecasting, our fitted
model predicts a waning volcanism producing only 3.296 new eruptions in the next million years. We then present the site disruption
probability as the chance that a new eruption will occur in the “hazard area” based on a model developed for licensing commercial
space launch and reentry operations in the space transportation industry. The results of the site disruption probability and
sensitivity analysis are summarized with a numerical table generated from a simple equation sufficient for practical use.
We also produce three-dimensional plots to visualize the nonlinearity of the intensity function associated with the underlying
model of a nonhomogeneous Poisson process and emphasize that the interpretation of site disruption probability should always
be accompanied by a compliance period. 相似文献
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Microcracks within the excavation damaged or disturbed zone (EDZ) in a salt-based radioactive waste repository (or an energy storage facility) can heal/seal by mechanical closure driven by compaction creep, by surface-energy-driven processes like diffusive mass transfer, and by recrystallization. It follows that permeability evolution in the excavation damaged zone around a backfilled or plugged cavity will in the short term be dominated by mechanical closure of the cracks, while in the longer term diffusive mass transfer effects are expected to become more important. This paper describes a contribution to assessing the integrity of radioactive waste repositories sited in rocksalt formations by developing a microphysical model for single crack healing in rocksalt. More specifically, single crack healing models for cracks containing a thin adsorbed water film are developed. These microphysical models are compared with single crack healing experiments, which conclusively demonstrate diffusion controlled healing. Calibration of unknown model parameters, related to crack surface diffusivity, against the experimental data enable crack healing rates under repository conditions to be estimated. The results show that after the stress re-equilibration that follows repository sealing, crack disconnection can be expected on a timescale of a few years at laboratory humidity levels. However, much longer times are needed under very dry conditions where adsorbed aqueous films are very thin. 相似文献
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.S. Pettitt C. Baker R.P. Young L.-O. Dahlström G. Ramqvist 《Pure and Applied Geophysics》2002,159(1-3):179-195
—?Two large-diameter boreholes have been excavated vertically from the floor of a tunnel at the Äspö Hard Rock Laboratory, Sweden. The two deposition holes will have simulated high-level radioactive waste canisters installed in them in an experiment undertaken to test the retrievability of waste from a proposed repository. Induced seismicity and other acoustic monitoring techniques have been used to investigate the Excavation Damaged Zone (EDZ) around the two holes. High-frequency acoustic emission (AE) monitoring has been used to delineate regions of stress-induced microfracturing on the millimetre scale. This has been shown to locate in clusters around the perimeter of the deposition hole at azimuths orthogonal to the far-field maximum principal stress. Three-dimensional velocity surveys have been conducted along ray paths that pass through the damaged region and through a stress-disturbed zone around the excavation. Induced microfracturing and stress disturbance have been observed as sharp decreases in velocity as the excavation proceeds through the rock mass. The combination of the high-resolution velocity measurements and the AE source locations has allowed the linking of the velocity measurements to a volume of excavation damaged rock. This has provided a quantitative estimate of the effect of the EDZ on the rock mass. 相似文献
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In Switzerland the geological storage in the Opalinus Clay formation is the preferred option for the disposal of spent fuel (SF) and high-level radioactive waste (HLW). The waste will be encapsulated in steel canisters and emplaced into long tunnels that are backfilled with bentonite. Due to uncertainties in the depth of the repository and the associated stress state, a concrete liner might be used for support of emplacement tunnels.Numerical reactive transport calculations are presented that investigate the influence of a concrete liner on the adjacent barrier materials, namely bentonite and Opalinus Clay. The geochemical setup was tailored to the specific materials foreseen in the Swiss repository concept, namely MX-80 bentonite, low-pH concrete (ESDRED) and Opalinus Clay. The heart of the bentonite model is a new conceptual approach for representing thermodynamic properties of montmorillonite which is formulated as a multi-component solid solution comprised of several end-members.The presented calculations provide information on the extent of pH fronts, on the sequence and extent of mineral phase transformations, and on porosity changes on cement–clay interfaces. It was found that the thickness of the zone containing significant mineralogical alterations is at most a few tens of centimeters thick in both the bentonite and the Opalinus Clay adjacent to the liner. Near both interfaces, bentonite–concrete liner and concrete liner–Opalinus Clay, the precipitation of minerals causes a reduction in the porosity. The effect is more pronounced and faster at the concrete liner–Opalinus Clay interface. The simulations reveal that significant pH-changes (i.e. pH > 9) in bentonite and Opalinus Clay are limited to small zones, less than 10 cm thick at the end of the simulations. It is not to be expected that the zone of elevated pH will extend much further at longer times. 相似文献
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The article considers the procedure aimed to identify and select the factors, events, and processes that can have an effect on the long-term safety of radioactive waste repository to be constructed at The Yenisei Site (Krasnoyarsk krai). The geological factors to be taken into account in the development of scenarios for safety assessment are determined. Tentative quantitative forecasts of radionuclide migration are made taking into account possible climate evolution and vertical rise of the territory. The sensitivity of radionuclide migration model to variations in these factors is assessed. 相似文献