Spectroscopic studies of transition-metal oxides, silicates, and pnictides: developing materials capable of sequestering nunclear waste

过渡金属氧化物、硅酸盐和磷族化物的光谱研究：开发能够封存核废料的材料

• 批准号: 386347-2010
• 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: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=507205
• 关键词: Spectroscopic; studies; transition; metal; oxides

With governments considering phasing out fossil fuel based power generators because of environmental concerns, nuclear energy is once again a serious alternative. Although the power generated by nuclear reactors is "clean", hazardous radioactive waste is produced. Canada supplies >25% of the worlds' uranium (U) supply (production value >$2.5 billion), with much of it destined for nuclear power facilities. To increase Canada's position in the U market, it is important to develop materials for use in the storage of nuclear waste. This waste can be sequestered in compounds that are densely packed and retard outward diffusion of the radioactive elements. The long-term goal of this research program is the development of ordered compounds that can sequester U in the structure and resist radiation induced structure damage. To initiate this research, model compounds representing host materials will be examined in order to gain a clear understanding of the relationship between crystal structure composition, bonding, electronic structure, and surface reactivity to the sequestration of actinides like U. In this program, pyrochlore ceramics (A2B2X6X'; A=Ca, Mn, Fe, rare-earths (RE); B=Ti,Nb,Ta; X/X'=O, F, OH), materials adopting the zircon (ASiO4; A=Zr, Hf) and zirconolite (A2B2O7; A/B=Ca, V, Zr, Ti, Hf) structures, amorphous silicates ([AO2]x[A'O2]y[SiO2]1-x-y; A/A'=Ti, Zr, Hf), and skutterudites (REM4Pn12; RE=La, Ce, Eu, Gd; M = Fe, Co; Pn (pnictide)=P, As, Sb, Bi) will be synthesized. The electronic structure and ability of these materials to be oxidized will be investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy, utilizing synchrotron radiation. Studying crystalline and amorphous silicates will allow for an examination of how radiation induced structure damage affects a materials ability to sequester U. (Many of the above materials also have applications in semiconductor devices, power generation, and refrigeration.) This research program is dedicated to applying X-ray spectroscopy to the study of the oxidation behaviour and changes in electronic structure with elemental substitution of the systems described above, so as to develop materials capable of sequestering nuclear waste.

由于环境问题，各国政府正在考虑逐步淘汰化石燃料发电机，核能再次成为一个重要的替代方案。 尽管核反应堆产生的电力是“清洁的”，但也会产生危险的放射性废物。 加拿大的铀 (U) 供应量占世界总量的 25% 以上（产值 > 25 亿美元），其中大部分用于核电设施。 为了提高加拿大在铀市场的地位，开发用于储存核废料的材料非常重要。 这种废物可以被隔离在致密堆积的化合物中，并阻止放射性元素向外扩散。该研究计划的长期目标是开发能够将铀隔离在结构中并抵抗辐射引起的结构损伤的有序化合物。 为了启动这项研究，将检查代表主体材料的模型化合物，以便清楚地了解晶体结构组成、键合、电子结构和表面反应性与锕系元素（如U）螯合之间的关系。在该项目中，烧绿石陶瓷（A2B2X6X'；A=Ca、Mn、Fe、稀土（RE）；B=Ti、Nb、Ta；X/X'=O、F、 OH）、采用锆石（ASiO4；A=Zr、Hf）和锆英石（A2B2O7；A/B=Ca、V、Zr、Ti、Hf）结构的材料、无定形硅酸盐（[AO2]x[A'O2]y[SiO2]1-x-y；A/A'=Ti、Zr、Hf）和方钴矿（REM4Pn12； RE=La、Ce、Eu、Gd； M=铁、钴；将合成Pn(pnictide)=P、As、Sb、Bi)。 这些材料的电子结构和被氧化的能力将通过 X 射线衍射、X 射线光电子能谱和 X 射线吸收光谱，利用同步加速器辐射进行研究。 研究结晶和无定形硅酸盐将有助于检查辐射引起的结构损伤如何影响材料螯合U的能力。（上述许多材料也应用于半导体器件、发电和制冷。）该研究计划致力于应用X射线光谱法研究上述系统的元素替代的氧化行为和电子结构的变化，从而开发能够螯合核的材料 浪费。