Crystal chemistry and phase manipulation in Synroc

Vance, ER; Moricca, SA; Thorogood, GJ; Lumpkin, GR

Crystal chemistry and phase manipulation in Synroc

Date

1990-08

Authors

Publisher

Trans Tech Publications

Abstract

Synroc is a multi-phase titanate ceramic designed for geological immobilisation of radioactive waste produced reprocessing by nuclear fuel from power reactors [1]. The main crystalline phases are hollandite, perovskite, zirconolite, and reduced titanium oxide. The compositions of these phases and the nuclides they can incorporate in solid solution are shown in Table 1. The main (Synroc-C) formulation is designed for Purex reprocessing waste and the standard composition is (wt%) : AI203(4.3); BaO(4.4); CaO(8.8); ZrO2(5.6); TiO2(57.9); waste oxides (20). The loading of high-level waste (HLW) oxides can be varied if desired, but probably cannot exceed a value of 30-35% [2]. Several variants of this composition have been fomulated at the laboratory scale, with Synroc-D, E and F being directed towards Savanah River (U.S.A.) military waste, encapsulation of high-level nuclear reprocessing waste and unreprocessed spent fuel respectively [3-5]. The present work is also aimed at modifying the Synroc-C composition in the following respects (a) significant reduction of the various fraction of perovskite phase in Synroc-C (b) incorporation of process chemicals and (c) incorporation of Al-rich and actinide-rich wastes.

Description

Physical copy held by ANSTO Library at DDC: 620.14/9 Conference name also called "2nd International Ceramic Conference and Exhibition" on preface.

Keywords

Synroc process, Synthetic rocks, Titanates, Geologic deposits, Radioactive waste disposal, Hollandite, Perovskite, Zirconolite, Titanium oxides, Chemical composition, Wastes, Oxides, Savannah River, Actinides

Citation

Vance, E. R., Moricca, S., Thorogood, G. J., & Lumpkin, G. R. (1990). Crystal chemistry and phase manipulation in Synroc. Paper presented to the International Ceramic Conference (AUSTCERAM 90: ceramics technology - sharing the knowledge), Perth, Western Australia, 26-31 August 1990. Key Engineering Materials, 48-50, 717-721.