A solid-state and X-ray spectroscopic study of transition-metal oxides: Developing materials for the sequestration of nuclear waste

过渡金属氧化物的固态和 X 射线光谱研究：开发用于封存核废料的材料

• 批准号: RGPIN-2015-04156
• 负责人: Grosvenor, Andrew
• 金额: $ 2.55万
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=652518
• 关键词: solid; state; ray; spectroscopic; study; solid; state; ray; spectroscopic; study

INTRODUCTION: Many governments are considering expanding their fleet of nuclear power plants because of environmental concerns and the dwindling supply of fossil fuels. However, nuclear reactors produce radioactive waste. The long-term objective of this research program is the development of materials that can sequester nuclear waste.******OBJECTIVE 1: EFFECT OF THE STRUCTURE ON THE RADIATION RESISTANCE OF OXIDES: Titanium-containing crystalline oxides have received considerable attention for the sequestration of actinides because of their high chemical durability. A negative aspect of using crystalline materials for this application is that the decay of radioactive elements can result in the material becoming amorphous. The ability of materials to resist being damaged by radiation can be related to the structure. The objective of this study is to investigate the structural characteristics of a series of metal oxides containing corner-, edge-, and/or face-sharing metal-O polyhedra to understand the influence of crystal chemistry on the structural stability of the material. A comparative study of brannerite-, pyrochlore-, zirconolite-, and columbite-type oxides will be performed. Materials will be synthesized by solid-state methods and implanted using a beam of high-energy ions, which is an accepted method of simulating the effect of radioactive decay on a material. All materials will be studied by X-ray diffraction (XRD) and synchrotron radiation-based spectroscopic techniques.******OBJECTIVE 2: DEVELOPING GLASS-CERAMIC COMPOSITES: Spent nuclear fuel pellets are composed of a variety of fission products. We propose that glass-ceramic composites offer unprecedented flexibility for the sequestration of fission products. The objective of this study is the synthesis of glass-ceramic composites containing pyrochlore-, brannerite, or zirconolite-type oxides surrounded by a borosilicate glass. Composites involving slag from steel production will also be investigated. ******OBJECTIVE 3: THE INFLUENCE OF SYNTHETIC METHOD ON SITE DISORDER: Low-temperature synthesis methods are more economical to produce nuclear waste sequestration materials on the industrial scale compared to high-temperature methods. Site disorder within a structure may impact the resistance of the material to radiation-induced damage. The objective of this study is to determine how the synthetic method affects the metal site-disorder in zirconolite-, pyrochlore-, and perovskite- type oxides. ******SIGNIFICANCE: It is important to investigate various strategies to handle nuclear waste if we are to increase our reliance on nuclear power. This research program will be unique in that we will study how the resistance of materials to radiation damage changes depending on crystal structure, composition, and synthetic method. This program will also train students in solid-state chemistry and X-ray spectroscopy.

简介：许多政府正在考虑由于环境问题和化石燃料的供应减少，因此正在考虑扩大其核电站的舰队。但是，核反应堆产生放射性废物。该研究计划的长期目标是开发可以隔离核废料的材料。******目标1：结构对氧化物的辐射抗性的影响：含钛晶体的氧化物因其较高的化学耐用性而受到了隔离乙阳性剂的关注。在此应用中使用结晶材料的一个负面方面是放射性元件的衰减会导致材料变得无定形。材料抵抗被辐射损坏的能力可能与结构有关。这项研究的目的是研究一系列含有角，边缘和/或面部共享金属氧化金属氧化物的结构特征，以了解晶体化学对材料结构稳定性的影响。将进行对麸皮，pyrochlore-，锆石和哥伦比石型氧化物的比较研究。材料将通过固态方法合成，并使用高能离子束植入，这是一种模拟放射性衰变对材料的影响的公认方法。所有材料将通过X射线衍射（XRD）和基于同步加速器辐射的光谱技术研究。我们提出，玻璃陶瓷复合材料为静止产物的隔离提供了前所未有的灵活性。这项研究的目的是合成含有硼硅酸盐玻璃包围的含有pyrochlore-，brannerite或锆型氧化物的玻璃陶瓷复合材料。还将研究涉及钢渣的复合材料。 ******目标3：合成方法对现场障碍的影响：与高温方法相比，低温合成方法在工业规模上产生核废料固隔材料更经济。结构内的位置障碍可能会影响材料对辐射引起的损伤的阻力。这项研究的目的是确定合成方法如何影响锆石，pyrochlore-和perovskite-型氧化物中的金属位点。 ******意义：如果要增加我们对核电的依赖，则必须调查各种策略来处理核废料。该研究计划将是独一无二的，因为我们将研究材料对辐射损伤的抗性如何根据晶体结构，组成和合成方法而变化。该计划还将培训学生进行固态化学和X射线光谱法。