The preperation and examination of the high temperature oxidation of air sensitive materials: studying materials for the sequestration of nuclear waste

随着以化石燃料为基础的发电机因环境问题而被逐步淘汰，核能再次成为一种重要的替代能源。尽管核反应堆产生的电力被认为是“清洁的”，但也会产生有害的放射性废物。加拿大供应全球铀(U)供应量的25%(产值25亿美元)，其中很大一部分将用于核电设施。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是很重要的。格罗夫纳小组发起的这项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。为了开始这项研究，首先将考察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、成键、电子结构和表面反应性之间的关系，以封存像U这样的吖系元素。特别感兴趣的是考察可能的主体材料在各种条件下的高温氧化。这笔RTI赠款的一部分将用于购买高温管式炉，以氧化具有锆英石(ASIO4；A=Zr、Hf)和Skutterudite(REM4Pn12；稀土(RE)=La、Ce、Eu、Gd；M=Fe、Co；Pn(磷镍)=P、As、Sb、Bi)结构的材料。管式炉将能够在很长一段时间内将材料加热到高达1700摄氏度的温度，并允许在受控环境中进行实验。利用同步辐射，用X射线衍射、X射线光电子能谱和X射线吸收光谱研究了合成材料的电子结构和氧化行为。用来生产被研究材料的稀土元素、稀土元素和稀土元素是对空气敏感的。为了生产纯净的材料，最好将这些元素操作并存储在手套盒中。此外，出于安全原因，最好在可以在正负压力下操作的手套盒中操作放射性材料。用这笔RTI拨款购买的物品是推动这项研究计划向前发展所必需的。

With fossil fuel based power generators being phased out because of environmental concerns, nuclear energy is once again a serious alternative. Although the power generated by nuclear reactors is considered "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. The long-term goal of the research program initiated by the Grosvenor group 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 first 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. Of particular interest is the examination of the high temperature oxidation of possible host materials under various conditions. Part of this RTI grant will be used to purchase a high temperature tube furnace to oxidize materials having the zircon (ASiO4; A=Zr, Hf), and skutterudite (REM4Pn12; rare-earth (RE)=La, Ce, Eu, Gd; M = Fe, Co; Pn (pnictide)=P, As, Sb, Bi) structures. The tube furnace will be able to heat materials to temperatures as high as 1700C for extended periods of time and will allow for the experiments to be performed in a controlled environment. The electronic structure and oxidation behaviour of the materials to be synthesized will be investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy, utilizing synchrotron radiation. The rare-earths, pnictides, and actinides used to produce the materials to be studied are air sensitive. To produce pure materials, it is best to manipulate and store these elements in a glovebox. Further, for safety reasons, manipulation of radioactive materials in a glovebox that can operate under either a positive or negative pressure is preferred. The items to be purchased with this RTI grant are needed to propel this research program forward.