1例急性铀中毒案例的33年医学随访

本文报道对1例硝酸铀酰复合烧伤致急性铀中毒案例进行了33年的医学随访,以观察和研究人体急性铀中毒后的远期效应。随访期间研究观察的内容：①主诉症状和其尿铀检测;②临床实验室检查：外周血像及骨髓像,肾功能,肝功能,对细胞遗传学的影响,用放免分析方法检测甲状腺、肾上腺的内分泌功能,免疫功能检查包括细胞免疫功能和体液免疫功能,代谢功能检查包括糖耐量试验、胰岛素释放试验、脂代谢,细胞化学检查包括淋巴细胞糖元和粒细胞碱性磷酸酶,神经系统损伤效应,心肺等功能检查;③L的生育能力和遗传效应,及对其子女的随访。结果表明：外周血及骨髓功能正常;肾功能基本恢复;肝功能正常;淋巴细胞染色体畸变率检有染色体型畸变和染色单体畸变;细胞遗传学检查有环状体、双着丝粒体及断片等染色体型畸变,还有以单体断片和碎片为主的染色单体畸变;其他检查如甲状腺、肾上腺内分泌功能,细胞和体液免疫功能,代谢功能检查、淋巴细胞糖元和粒细胞碱磷酶检查基本正常;生育能力未受影响,子女体质差,疾病易感性高、抗病毒能力差;儿子不育,女儿妊娠期胎儿发育不良。     

赣杭构造带某铀矿区地下水中铀的存在形式研究北大核心CSCD

为研究铀矿区地下水化学性质对铀的存在形式的影响,本文以赣杭构造带某铀矿区地下水为研究对象,在对9个典型采样点地下水化学成分分析的基础上,采用数理统计软件SPSS 18.0和地球化学模拟软件PHREEQC及llnl.dat数据库,探究了研究区内地下水水化学特征及U的存在形式。结果表明:本研究区地下水水化学类型以HCO_(3)-Na与HCO_(3)-Na·Ca为主,U含量与Ca^(2+)和Mg^(2+)浓度体现出较强正相关性,与SO_(4)^(2-)的相关性次之;地下水中U元素主要以六价为主,几乎占100%,主要存在形式依次为UO_(2)(CO_(3))_(2)^(2-)、UO_(2)(CO_(3))_(3)^(4-)、UO_(2)CO_(3)、UO_(2)(OH)2、UO_(2)(OH)_(3)^(-)、UO_(2)OH^(+)等6种,其中UO_(2)(CO_(3))_(2)^(2-)占绝对优势,整体以碳酸铀酰形式为主,这也与研究区地下水酸碱性相对应。     

UMo/Al弥散型燃料元件溶解回收工艺研究

以配制好的混合碱(NaOH和NaNO3)为UMo/Al弥散型燃料元件样品铝包壳和铝基体的溶解液,将不合格的UMo弥散型燃料元件的包壳和弥散基去除,并计算铀损失率;采用金相显微镜分析UMo合金粉末的粒度分布,并用X射线衍射分析其相结构与成分.初步实验结果表明:随着NaOH浓度增大,铀损失率增大;随着NaNO3浓度的增大,...     

Modeling of geochemical processes related to uranium mobilization in the groundwater of a uranium mine

This paper describes the processes leading to uranium distribution in the groundwater of five boreholes near a restored uranium mine (dug in granite), and the environmental impact of restoration work in the discharge area. The groundwater uranium content varied from <1 microg/L in reduced water far from the area of influence of the uranium ore-containing dyke, to 104 microg/L in a borehole hydraulically connected to the mine. These values, however, fail to reflect a chemical equilibrium between the water and the pure mineral phases. A model for the mobilization of uranium in this groundwater is therefore proposed. This involves the percolation of oxidized waters through the fractured granite, leading to the oxidation of pyrite and arsenopyrite and the precipitation of iron oxyhydroxides. This in turn leads to the dissolution of the primary pitchblende and, subsequently, the release of U(VI) species to the groundwater. These U(VI) species are retained by iron hydroxides. Secondary uranium species are eventually formed as reducing conditions are re-established due to water-rock interactions.     

Inorganic ligand-modified, colloid-enhanced ultrafiltration: A novel method for removing uranium from aqueous solution

Inorganic ligand-modified, colloid-enhanced ultrafiltration (ILM-CEUF) is as a novel membrane-based separation method for selectively removing target ions from aqueous solution. Traditional colloid-enhanced ultrafiltration (CEUF) is a well-established membrane-based separation technique that can be used to separate metal ions from other aqueous solution components. Ligand-modified, colloid-enhanced ultrafiltration (LM-CEUF) uses organic ligands that selectively complex target ions and also associate with a water-soluble colloid, such as a surfactant micelle or polyelectrolyte. The colloid, associated -ligand, and target ion are then concentrated using an ultrafilter, producing a filtrate with a low concentration of the target ion. While traditional LM-CEUF techniques are able to provide quantitative separations of a variety of ionic pollutants, the high costs of the chelating agents make such techniques nonviable in most remediation schemes. This study investigated the replacement of organic ligands with carbonate for the selective removal of U(VI) from aqueous solution.In slightly to moderately basic solutions containing carbonate, UO₂(CO₃)₃⁴⁻ can be made to dominate the U(VI) speciation. Using poly(diallyldimethylammonium) chloride, the effectiveness and efficiency of ILM-CEUF for removing U(VI) from other aqueous solution components was investigated as a function of carbonate concentration, pH, and ionic strength. Uranium separations of greater than 99.6% were achieved; even in the presence of large excesses of competing ions. The specific separation of U(VI) from Sr²⁺ was also examined.     

采用磁种分选法处理铀矿石的研究

本文叙述了通过人工有选择性的磁覆盖来增强含铀矿物磁性的磁种分选法的研究工作。该方法可使某些含铀矿物与脉石在中磁场强度的磁选机中进行分离,而不必采用强磁选。文中论述了赛马矿石、宁都梅花山表外矿石、721-7扩大样采用磁种分选法选矿的条件和试验结果,并对分选机理进行了初步探讨。     

Detection and analysis of the microdistribution of uranium in the gills of freshwater Corbicula fluminea by SIMS technique

The microdistribution of uranium in the gills of freshwater bivalve Corbicula fluminea following chronic direct exposure to this radioelement has been investigated using the SIMS technique. Different exposure levels and exposure durations have been studied. The SIMS mass spectra and ²³⁸U⁺ ion images produced with a SIMS CAMECA 4F-E7 show an U accumulation with the lower aqueous U concentration (20 μg/L) and the influence of the exposure levels on the bioaccumulation capacities. Furthermore, the ionic images display a heterogeneous distribution of uranium within the gill structure whatever the exposure conditions are. This study, in keeping with the ENVIRHOM French research program, was led to the conclusion that ion microscopy is an appropriate analytical method for trace elements and can give elemental cartography in a biological tissue section.     

铀氢锆堆物理计算模型与程序

文中叙述基于两维四群中子扩散理论的铀氢锆堆物理计算模型及程序,以及用该模型计算的国外 TRIGA 堆的临界,控制棒效率等数据.     

Rietveld法模拟计算金属铀真空热氧化膜物相的含量

在400℃、500℃和600℃下对表面已氧化的金属铀进行真空热氧化退火处理，生成银白色的氧化膜表面。采用、XRD对氧化膜的成分进行了表征，并用Rietveld方法定量分析了金属铀真空热氧化膜中物相的含量。结果表明400℃和500℃时氧化膜主要为U和UO2，600℃时氧化膜中还出现了大量的UC，且U的含量明显增大，UO2含量减少。     

Analysis of on-line maintenance strategies for -out-of- standby safety systems

The objective of this paper is to compare the performance of three on-line test and maintenance strategies (corrective maintenance, preventive maintenance and predictive maintenance) for standby k-out-of-n safety systems. Each channel of the k-out-of-n system is modelled by an age-dependent unavailability model to reflect the effect of maintenance on the aging process. The system unavailability, the probability of spurious operation and the overall cost under the above maintenance strategies are analyzed and compared to obtain the optimal maintenance strategy. Sensitivity analyses are performed to reveal the effect of different model parameters on the system performance. A standby safety system in Canadian Deuterium–Uranium (CANDU) Nuclear Power Plants (NPPs), the Shutdown System Number One (SDS1), is used to illustrate the proposed analysis and the procedure. It is concluded that maintenance should neither be performed too frequently nor too rarely. When the system deteriorates very slowly, the corrective maintenance is more preferable than the preventive and predictive maintenance. When the failure rate of the system is high, the preventive maintenance results in the best system performance.