Modelling of long-term diffusion–reaction in a bentonite barrier for radioactive waste confinement

Bentonites have been proposed as buffer material for barriers in geological disposal facilities for radioactive waste. This material is expected to fill up by swelling the void between the canisters containing the waste and the surrounding ground. However, the bentonite barriers may be submitted to changes of humidity, temperature variation, fluid interaction, mass transport, etc. This could modify the physico-chemical performance of the barrier, mainly on the interface with the steel container and with the geological barrier. The engineered barrier development necessitates thus the study of the physico-chemical stability of its mineral component as a function of time under the conditions of the repository in the long-term.The purpose of the present study was two-fold. Firstly, it was hoped to simulate the chemical transformations (geochemical and cation exchange reactions) coupled with diffusion of chemical-elements into the engineered barrier under repository conditions by applying a thermokinetic hydrochemical code (KIRMAT: Kinetic Reactions and Mass transport).Secondly, it was hoped to apply a simplified method to estimate the swelling capacity evolution by a volume balance in the fluid-saturated engineered barrier, considering that the decay of swelling capacity is directly proportional on the volume of transformed montmorillonite and, taking into account that it may be partially compensated by the volume of neo-formed swelling clays.The system modelled herein was considered to consist of 1-m thick zone of water-saturated engineered barrier. This non-equilibrated system was placed in contact with a geological fluid on one side, which was then allowed to diffuse into the barrier, while the other side was kept in contact with a source of metallic iron. Reducing initial conditions(P_O2 0; Eh = − 200 mV) and a constant reaction temperature (100 °C) were considered.The results showed that the EB in contact with the geological fluid was highly transformed after 10,000 years, whereas the most significant chemical processes were illitization, cation exchange and saponization, extending up to 20 cm into the EB. Chemical transformations of minor importance in the EB were identified as well, such as a neo-formation of silicates (quartz, cristobalite), anhydrite, laumontite, magnetite and chlorite in the system.A simplified method based on volume balance showed that the swelling capacity of the bentonite barrier is slightly affected after 10,000 years of diffusion–reaction (D close to 1) because the volume of neo-formed swelling-clays is almost directly proportional to the volume of transformed Na/Ca-montmorillonite, except for a strong illitization and/or neo-formation of non-swelling clays. In the present study, this simple approach predicted that the decay of swelling capacity of the engineered barrier is drastically affected close to the geological barrier-engineered barrier interface. Out this zone the swelling capacity decay lies between 5% and 11%.     

基于温度影响的BOTDR监测数据实验研究

文章以布里渊散射光时域反射测量计(BOTDR)工作原理为基础,以监测工作中常用的φ0.9SM单芯紧套光纤在恒温实验室内的实验数据为依据,采用统计分析和线性回归方法,对其监测数据的环境温度影响进行了校正分析,有效剔除了因环境温度影响而造成的BOTDR监测数据假应变,取得了良好效果.     

浅析地质资料汇交人合法权益保护制度及完善

地质资料蕴含着丰富的地质、矿产、国土资源的信息,在国民经济建设和地质矿产科学研究,矿业经济可持续发展,减少地质矿产投资风险和重复投入,加强矿产资源合理开发利用等方面具有重要意义。为更好推进地质资料的社会化服务进程,现行《地质资料管理条例》确立了地质资料统一汇交、权益保护和公开利用三项基本制度。本文从权利归属、权利性质、保护期限以及权利救济手段等方面,对汇交人权益保护制度进行解读和分析,目的在于为我国地质资料汇交人合法权益保护制度的完善提供有益探索。     

CH375在氡析出率仪中的应用

本文论述了USB接口芯片在氡析出率仪中的应用。介绍了CH375的特点，给出了CH375与单片机的硬件接口电路和软件的设计思路，最终实现了氡析出率仪从u盘读写数据的功能。     

无线控制的负延时存储测试方法

针对在恶劣环境下冲击波场超压测试传统方法中布线难、干扰大、无法实时监测和及时获取数据等问题,提出了一种无线控制的负延时存储测试方法。存储测试装置由传感器、模拟适配调理电路、A/D变换器、存储器、控制电路、接口、电池组成,由单片机与CPLD共同控制两片NAND结构闪存实现高速完整存储。Zigbee无线传感器网络技术用于对整个测试系统的触发、采集和数据传输等操作的控制。实验表明:这种新型测试方法具有可无线遥控、微功耗、抗高冲击、抗干扰、工作稳定可靠等特点,适于恶劣环境下数据记录和传输。     

Soil gas radon, indoor radon and gamma dose rate in CZ: contribution to geostatistical methods for European atlas of natural radiations

A comparison of Czech indoor radon data, soil gas radon dataand gamma dose rate was performed on the data sets of 92 276indoor radon measurements in existing dwellings (National RadiationProtection Institute – NRPI), database of 9500 test sitesof soil gas radon measurements (Czech Geological Survey –CGS) georeferenced to levels of gamma dose rate map. Three methodswere used for the study of soil gas Rn–indoor Rn relationship:(1) based on the vectorised point soil gas and indoor data relatedto vectorised areas of gammadose rate, (2) vectorised soil gas–indoordata based on vectorised geological units and (3) soil gas andindoor data related to grid squares 10 x 10 km². The first andsecond methods seem to express the closer correlation comparedwith the third one, however the correlation using the thirdmethod is influenced by the representativeness of data valuein the square of 100 km² area. On the other hand, the thirdmethod can be used for the overview coverage of the continentalareas with lack of input information.     

巴河流域平推式崩塌机理研究及防治思路

通过开展四川省巴河流域地质灾害的调查,共获得了崩塌地质灾害点11处,其中平推式崩塌为5处,占总崩塌数的45%。研究显示该类型的崩塌具有平推式滑坡相似的特征:坡体上部砂岩、底部夹层为泥岩;坡角近垂直;坡体后缘发育有平行坡面、出露于地表的裂隙,裂隙两侧封闭。强降雨时,雨水流入裂隙,产生的动水压和静水压,还有高水头产生的劈裂作用,致使裂隙的加速发育。上部的砂岩层沿着泥岩层向外推挤,从而产生临空面发生崩塌。灾害体会受水的影响,产生临空面—崩塌—再产生临空面—再崩塌。所以要根治该类型的崩塌隐患,治理措施应注重考虑防止地表水流进裂隙、遏制裂隙的发育。     

矿产资源开发生态补偿法律制度研究

本文论述了建立矿山环境生态补偿制度的必要性,论证了制订矿产资源开发生态补偿法律制度的原则。提出了矿产资源开发生态补偿经济政策的建议,一是税收制度"绿色化",二是对矿山环境治理恢复的土地给予优惠政策;同时,应建立矿山环境治理保证金制度。     

EDTA滴定法与原子吸收光谱法相结合测定多金属矿中锌

样品以硫酸铵-氢氧化铵一次沉淀分离后,用EDTA络合滴定法测定溶液中的锌含量,并将沉淀以盐酸溶解后用原子吸收光谱法测定其中吸附的锌含量,二者之和为样品中锌的总含量,提出了一种EDTA滴定法和原子吸收光谱法相结合测定多金属矿中锌含量的新方法,从根本上克服了絮状胶体沉淀等对锌的吸附。实验表明,在氨性介质中,铁锰等元素的沉淀会对溶液中的锌产生吸附,使锌的测定结果偏低,铅、镉也会对锌的测定造成影响。而采用本方法测定铅锌矿标准物质和锌精矿标准物质中锌的含量,测定值与认定值一致,相对标准偏差（RSD）小于0.4%。     

MapGIS数据批量导入手持GPS的方法

传统的化探扫面工作中,一般是利用手工逐个输入航点以实现批量导入航点,该方法不但效率低下而且容易出错。通过多次实践,利用MapGIS、记事本,"GPS帮帮"及MapSource等软件,生成MapSource数据交换格式GPX文件,实现了快速高效地向手持GPS中批量输入航点数据的目标。航点验证证明了方法的可行性。该方法不需要编程,实用性强,不但减少了人为误差,同时也提高了工作效率,给地质人员的野外工作带来极大的便利。