Recent concepts for nuclear fuel and targets for transmuting long-lived radionuclides (minor actinides) and for the development of innovative Gen-IV nuclear fuel cycles imply fabricating host phases for actinide or mixed actinide compounds. Cubic stabilized zirconia (Zr, Y, Am)O2−x is one of the mixed phases tested in transmutation experiments. Wet chemical routes as an alternative to the powder metallurgy are being investigated to obtain the required phases while minimizing the handling of contaminating radioactive powder. Hydrolysis of zirconium, neodymium (a typical surrogate for americium) and yttrium in aqueous media in the presence of acetylacetone was firstly investigated. Progressive hydrolysis of zirconium acetylacetonate and sorption of trivalent cations and acacH on the zirconia particles led to a stable dispersion of nanoparticles (5–7 nm) in the 6–7 pH range. This sol gels with time or with temperature. The application to americium-containing solutions was then successfully tested: a stable sol was synthesized, characterized and used to prepare cubic stabilized zirconia (Zr, Y, Am)O2−x.
最近,核燃料的概念以及用于嬗变长寿命放射性核素(次
锕系元素)和开发第四代核燃料循环的创新方案,意味着需要制造
锕系元素或混合
锕系元素化合物的母相。立方稳定
氧化锆(Zr, Y, Am)O2−x是嬗变实验中测试的混合相之一。作为粉末冶
金的替代方案,湿
化学路线正在研究中,以获得所需的相,同时减少对污染放射性粉末的处理。首先研究了在
乙酰丙酮存在下,
锆、
钕(
镅的典型替代物)和
钇在
水介质中的
水解。
乙酰丙酮锆的逐步
水解和三价阳离子和
乙酰丙酮铵在
氧化锆颗粒上的吸附导致纳米颗粒(5-7 nm)在6-7 pH范围内的稳定分散。这种溶胶凝胶会随着时间或温度的变化而变化。随后,含
镅溶液的应用成功进行了测试:合成了一种稳定的溶胶,并对其进行了表征,用于制备立方稳定
氧化锆(Zr, Y, Am)O2−x。