Study of mineral grains extracted from the Chernobyl “lava”статья
Информация о цитировании статьи получена из
Web of Science,
Scopus
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Дата последнего поиска статьи во внешних источниках: 20 января 2021 г.
Аннотация:Results of spectroscopic and microstructural investigation of mineral grains extracted from Chernobyl “lava”-like fuel-containing materials – Chernobyl “lava” - are presented. Raman, photoluminescence and infra-red spectra reveal the presence of abundant U4+, traces of Sm3+ and Cr3+ in grains of U-containing zircon and ZrO2. No oxidation of UO2 particles is observed. Studied ZrO2 grains mostly consist of monoclinic polymorph and are often twinned. Raman spectra indicate the presence of a tetragonal polymorph, which is likely stabilized by the presence of uranium. It is suggested that spontaneous transformation of partially stabilized tetragonal (Zr,U)O2 to the monoclinic phase, and a corresponding volume expansion, are likely important factors affecting the rate of mechanical degradation of the “lava”. Transmission Electron microscopy of U-rich zircon suggests an absence of precipitation of an independent U-containing phases, implying that U is fully incorporated within zircon lattice as an impurity. Grains of rutile, corundum, quartz and natural zircon originating from construction materials of the reactor are described. Results obtained here are important for validation of computer codes describing severe nuclear accidents.