Open AccessPhase and chemical stability of simulated waste forms Gd2Zr2-xCexO7(0≤ x≤ 2.0)
Author(s) -
卢喜瑞,
董发勤,
胡淞,
Wang Li,
吴彦霖
Publication year - 2012
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.61.152401
Subject(s) - cerium , fluorite , materials science , extraction (chemistry) , pyrochlore , chemical stability , seawater , chemical composition , analytical chemistry (journal) , nuclear chemistry , phase (matter) , chemistry , chromatography , metallurgy , oceanography , organic chemistry , geology
In order to investigate phase change and chemical stability of pyrochlore Gd2Zr2O7 used for immobilizing Pu(Ⅳ), tetravalent cerium is used as the simulacrums for plutonium with tetravalence, and Gd2Zr2-xCexO7(0≤ x≤ 2.0) series samples are successfully synthesized by high temperature solid reaction and using Gd2O3 and ZrO2 powders as starting materials. The experiments of long-term chemical stability are conducted in synthetic seawater at 40 °C and 70 °C separately. The XRD diffractive data and extraction ratio of as-gained samples are collected by the help of X-ray diffraction (XRD) instrument and inductively coupled plasma mass spectrometry. The results indicate that the phases of compounds change from pyrochlore to fluorite-type phase when the value of x is more than 0.08. Extraction ratios of Gd3+, Zr4+ and Ce4+ in waste forms increase with the increase of immersion time in synthetic seawater. The extraction ratio of waste form at 70 °C is higher than at 40 °C. The highest extraction ratios of Gd3+, Zr4+ and Ce4+ for 42 days are no more than 0.032, 0.003 and 0.032 μg·ml-1 respectively.