COMPREHENSIVE INVESTIGATION OF SELECTED METAL OXIDES WITH APPLICATION FOR CLEAN ENERGY

对选定的金属氧化物及其在清洁能源中的应用进行全面研究

• 批准号: RGPIN-2014-04274
• 负责人: Szpunar, Barbara
• 金额: $ 1.38万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610934
• 关键词: COMPREHENSIVE; INVESTIGATION; SELECTED; METAL; OXIDES

This proposal concerns the application of multi-scale modeling at both nuclear and atomistic levels. This work is unique because it combines nuclear simulations with materials modeling. Although the techniques to be used are well established, they have never been coupled together as proposed here. This work will apply state of the art, first principles (predictive) and improved modeling to investigate structural, optical, mechanical, and thermo-physical properties of novel and nuclear materials. The overall objective of this research is to develop a fundamental understanding of the properties of novel and nuclear materials. The short-term objectives over the next three years focus on (1) use of combined simulation of the radiation sources and atomistic molecular dynamics modeling of nuclear materials to achieve a better, fundamental understanding of the effects of radiation; (2) use of ab initio, predictive, and semiempirical methods to study the effect of radiation induced defects on the properties of materials on a large scale; (3) determining structural, mechanical, and thermo-physical properties for various nuclear fuels from simulations; (4) investigating optical and electronic properties of actinide oxides (with emphasis on U3O8); and (5) preparing interactive code for a reactor safety course. The semiconductive properties of uranium oxides are of interest since these oxides have dielectric constants much higher (e ~ 20) than SiO2 (3.5). Depleted uranium oxides can be recovered from nuclear waste and have potential application in solar cells and electronics. They are also a by-product of the production of enriched uranium. U3O8 is the most stable uranium oxide but there are no experimental data available about optical band gap. We have the required expertise to investigate the electronic structure and the band gap of U3O8, both experimentally (at Canadian Light Source) and theoretically. Cameco Inc. in Saskatoon can provide us with samples of depleted U3O8 that can be safely examined. Once the band gap has been determined both the optical and mechanical properties will be accurately determined from first principles calculations. They will be used to evaluate the potential application of U3O8 in solar panels. It will lay the groundwork for new applications for uranium oxides in the province of Saskatchewan beyond the current export of uranium ore. Accurate data on the mechanical and structural properties of U3O8 would allow the prediction of stresses when urania volume increases due to oxidation during an accident in a reactor or waste storage compartment. We have studied various nuclear fuels theoretically, especially inherently safe thoria with high thermal conductivity that prevents fuel melting by more efficient heat dissipation. However the experimental data for thermal conductivity of fuel show big differences and implications of burn-up-induced degradation is not well known. Monte Carlo code will be used to simulate the atoms displacements in fuels in operating fuel rods and a physical burnup will be evaluated. The parameters in classical molecular dynamics code will be tuned up using the first principles calculations and it will be used to evaluate the degradation of the thermal conductivity by the physical burnup. The comparison between urania and thoria fuel behaviours will be investigated. The developed thermal conductivity correlations for pure fuel and with inclusion of defects will be used in the new interactive software for multidisciplinary investigation of nuclear reactor safety and investigation of fuel melting in an accident similar to Fukushima. It is critical for the design of safer reactors to have access to new methods of simulating the properties of uranium oxides and new safer fuels (thoria, UC).

该提案涉及在核和原子水平上使用多尺度建模的应用。这项工作是独一无二的，因为它将核模拟与材料建模相结合。尽管要使用的技术已经确定，但它们从未像这里提出的那样结合在一起。这项工作将采用艺术状态，第一原理（预测）和改进的建模，以研究新颖和核材料的结构，光学，机械和热物质特性。这项研究的总体目的是对新颖和核材料的特性发展基本理解。接下来的三年中的短期目标集中在（1）使用辐射源的合并模拟和核材料的原子分子动力学建模，以实现对辐射影响的更好，基本的理解； （2）利用从头算，预测和半经验方法研究辐射诱导的缺陷对大规模材料特性的影响； （3）确定模拟各种核燃料的结构，机械和热物质特性； （4）研究肌动蛋白氧化物的光学和电子特性（重点是U3O8）； （5）为反应堆安全课程准备交互式代码。 铀氧化物的半导体特性是感兴趣的，因为这些氧化物的介电常数（E〜20）高于SIO2（3.5）。可以从核废料中回收枯竭的铀氧化物，并在太阳能电池和电子中具有潜在的应用。它们也是富集铀生产的副产品。 U3O8是最稳定的氧化铀，但没有有关光条间隙的实验数据。我们具有研究电子结构和U3O8的带隙（在加拿大光源）和理论上所需的专业知识。萨斯卡通的Cameco Inc.可以为我们提供可以安全检查的耗尽U3O8的样本。一旦确定带隙，将通过第一原理计算准确确定光学特性和机械性能。它们将用于评估U3O8在太阳能电池板中的潜在应用。它将为萨斯喀彻温省铀氧化物的新应用奠定基础，超出当前铀矿石出口。关于U3O8的机械和结构特性的准确数据将允许在反应堆或废物储存室中事故期间因氧化而增加的压力预测应力。 我们已经从理论上研究了各种核燃料，尤其是具有高热电导率的固有安全的胸部，从而防止了更有效的热量耗散燃料融化。但是，燃料热导率的实验数据显示出很大的差异和燃烧引起的降解的含义。蒙特卡洛代码将用于模拟操作燃料棒中燃料中的原子位移，并将评估物理燃烧。经典分子动力学代码中的参数将使用第一个原理计算来调整，并将用于评估物理震动的导热率降解。脉脉和索尼亚燃料行为之间的比较将进行研究。 新的交互式软件将使用开发的用于纯燃料和包含缺陷的热导率相关性，用于在类似于福岛的事故中对核反应堆安全性的多学科研究和燃料熔化的研究。对于更安全的反应堆的设计至关重要的是，可以访问模拟铀氧化物和新的更安全燃料（Thoria，UC）的新方法。