Development of a ceramic waste form for high-level waste disposal

Abstract

Magnet errors and off-center orbits through sextuples perturb the dispersion and beta functions in a storage ring (SR), which affects machine performance. In a large ring such as the Advanced Photon Source (APS), the magnet errors are difficult to determine with beam-based methods. Also the non-zero orbit through sextuples result from user requests for steering at light source points. For expediency, a singular value decomposition (SVD) matrix method analogous to orbit correction was adopted to make global corrections to these fhnctions using strengths of several quadrupoks as correcting elements. The direct response matrix is calculated from the model of the perfect lattice. The inverse is calculated by SVD with a selected number of singular vectors. Resulting improvement in the lattice functions and machine performance will be presented.

Processing glass–pyrochlore composites for nuclear waste encapsulation

“…It is well-known that glass waste forms represent a good compromise due to the high solubility of high level wastes (HLW) and chemical durability of glasses, their radiation resistance and the capability to be processed at reasonably low temperatures, in particular borosilicate glass compositions [1][2][3][4][5]. However, many polycrystalline ceramic materials have been shown to possess higher chemical durability and radiation damage resistance than borosilicate glasses under storing conditions [1].…”

“…In their work a material belonging to the family of Synroc (ceramic materials particularly suitable to contain actinides) is described, which has been combined with a glass in order to form a composite. Another composite is described in the work of Esh et al [3]; where the crystalline phases are aluminosilicate zeolites which are mixed with glass frit and then hot isostatically pressed. Similar developments have been reported on hot isostatically pressed mixtures of glass and crystal forming components [4], in which most radioactive waste (95 wt%) resides in the crystalline phase encapsulated in the residual glassy phase.…”

Borosilicate and lead silicate glass matrix composites containing pyrochlore phases for nuclear waste encapsulation

“…Pyrochlore phases may be found for example within the multitude of crystalline phases in a Synroc waste [1]. In addition, Pu is known to substitute in other Zr containing ceramics such as zircon [14].…”

“…With the aim of exploiting both the advantages of glass waste forms and the radiation resistance of certain crystalline phases, waste forms based on composite materials containing ceramic and glass phases, or on specifically designed glass-ceramics, have been proposed for the immobilization of different types of radioactive waste [14][15][16][17][18][19], with some early concepts summarised in Refs. [20,21].…”

“…For example, it has been proposed that Synroc could be combined with a glassy phase to form a composite waste form [1]. Other ceramic-glass composite waste forms have been developed at Argonne National Laboratory, where aluminosilicate zeolite crystalline phases are combined with glass frit and hot isostatically pressed [14]. In similar developments, mixtures of glass and crystal forming components have been hot isostatically pressed at Idaho National Laboratory [15] obtaining a glass-ceramic in which most radioactive waste (95 wt%) resides in the crystalline phase encapsulated in the residual glassy phase.…”