Study of Glass-Ceramic Waste Forms

Abstract

Since the early of the 1990s the method of inductive melting in a cold crucible (IMCC) has been applied at SIA “Radon” for production of various wasteforms, including glasses and Synroc-type ceramics. Sphene-based glass-ceramics composed of glass and crystalline phases were considered as appropriate wasteform for High Level Waste immobilisation. Investigation of two glass-ceramic specimens prepared with the IMCC has been performed using optical microscopy, XRD, SEM/EDS, and TEM methods. The samples produced consist of vitreous and crystalline phases. The vitreous phase consists of two varieties of glass formed by the immiscibility of the initial melt onto two separate liquids. One of the glasses is observed as spherical microinclusions in the matrix glass. The glass of the microspheres are differed from the matrix glass composition by higher contents of Ca, Ti, Ce, Sr, Zr (or Cr), while the matrix glass contains higher amounts of Si, Al, and alkalies. The crystalline phases with sphene- and perrierite-like structures have been also occurred. Their total quantity reaches up to 50 vol.%. The synthetic perrierite has similar unit-cell parameters with its natural mineral analogs with the only exception in two-fold value of c dimension. Zr, Ce, and Sr are incorporated into synthetic sphene and perrierite, while Cs is hosted by the glass phases.

In-situ Raman and Brillouin light scattering study of the international simple glass in response to temperature and pressure

“…Cement [1][2][3][4], ceramics [5], and glass-ceramic composites [6][7][8][9][10][11][12][13][14] have been proposed as encapsulation materials, as well as glasses of various compositions [5,15]. Glass is promising for its innate ability of the amorphous network to accommodate a wide variety of elements, including the heavy actinides and fission products that result from nuclear energy generation or other processes such as nuclear weapons reclamation and medical treatments.…”

Cold Crucible Inductive Melting Technology – Application to Vitrification and Ceramization of High Level and Actinide Wastes

“…Zirconolite-rich ceramic contained about 80 vol.% zirconolite and ~20 vol.% extra phases: zirconia-based solid solution, rutile, glass. The latter may be present if protective putty contains silica [17]. Several tests using the CCIM for production of murataite ceramics with baseline composition (wt.%) 5 Al 2 O 3 , 10 CaO, 5 Fe 2 O 3 , 55 TiO 2 , 10 MnO x , 5 ZrO 2 , 10 (An,RE)O y and modified composition with increased ZrO 2 content at the expense of other oxides were conducted in lab-and bench-scale units (Table V).…”

Extra-Heavy Concrete and Cermet: Protective Materials with Enhanced γ-Ray Absorption

“…Borosilicate glassforming systems are convenient to study and are used on a commercial scale for immobilizing liquid high-level wastes [3][4][5][6][7][8][9][10][11][12][13][14]. In [15][16][17][18] it is shown that glass ceramic matrices can be used for solidifying radwastes containing up to 26 wt.% fissionproduct oxides. In DUAGG, the mass fraction of depleted uranium dioxide exceeds 90%.…”