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

点击翻译按钮获取中文摘要

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.