Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

TitleStudy on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents
Publication TypeJournal Article
Year of Publication2015
AuthorsSengupta, P, Mishra, RK, Soudamini, N, Sen, D, Mazumder, S, Kaushik, CP, Ajithkumar, TG, Banerjee, K
JournalJournal of Nuclear Materials
Volume467
Pagination144-154
Date PublishedDEC
ISSN0022-3115
KeywordsInteraction between refractory material and hazardous liquid, Nuclear waste immobilization, Vitrification melter
Abstract

Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as `glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. Al-27 and Si-29 NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 degrees C, 800 h exposure) are found to be 0.38 x 10(3) mu my(-1), 0.13 x 10(3) mu my(-1) and 4.75 x 10(3) mu my(-1) respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. (C) 2015 Elsevier B.V. All rights reserved.

DOI10.1016/j.jnucmat.2015.09.019
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

2.199

Divison category: 
Central NMR Facility