Electrochemical immobilization of Cs in single-crystalline SYNROC

摘要

The development of a disposal technique for the radiotoxic Cs-37 in nuclear wastes is one of the most urgent issues in nuclear fuel technology. An effective disposal method of Cs-137 is to immobilize it in it synthetic rock (SYNROC) material: cesium titanate hollandite. (137)Cs(x)Ti(S)O16 (I4/m, a = 10.2866(3) angstrom, c = 2.9669(1) angstrom). Practical applications of (CsxTi8O16)-Cs-137 have been restricted so far because the conventional synthetic method requires strong chemical reducers and reaction temperatures higher than 1250 degrees C. In this report. we present a milder preparation method of CsxTi8O16 by electrolysis of a mixture of Cs2MoO4 and TiO2 in ambient atmosphere at 900 degrees C. The Cs content in the resultant single-criytalline Cs1.35Ti8O16 is competitive with the highest value in polycrystalline Cs1.36 +/- 0.03Ti8O16 prepared by the conventional synthetic method. The electrochemical preparation of Cs1.35Ti8O16 is a promising way to immobilize a high quantity of Cs-137 ions in a stable f'orm of single-crystalline SYNROC. (C) 2006 Elsevier Inc. All rights reserved.