CHARACTERIZATION OF BOROSILICATE COMPOSITIONS FOR IMMOBILIZATION OF PU-CONTAINTNG SLUDGES

摘要

Corrosion resistances of borosilicate glasses incorporating of 50 wt.% of simulated Pu-containing sludges were studied using static and dynamic water flow leach tests at 90°C. It was shown that the normalized leach rate of the plutonium and uranium were < 0.001 and 0.01 g/m~2-day, respectively, and slightly depended on leach methods. The mass losses of Pu-containing glass for 14 days were 1,25 g/m~2for glass under static conditions and 1,56 g/m~2 under dynamic conditions. The largest mass losses at leaching are determined by dissolution of sodium, boron and silicon. The glasses surface was analyzed before and after leaching by Electron Probe Analysis (EMPA), scanning electron microscope (SEM) and x-ray diffraction (XRD) methods. The altered layer, which formed during leaching, is considerably impoverished in sodium and is enriched by uranium and iron.