Improved High-Alkali Low-Activity Waste Formulations (Final Report, Rev. 0)
High waste loading LAW glass formulations developed for ORP by VSL and EnergySolutions contain about 0.5 wt% Cr 2 O 3 as an additive to control K-3 refractory corrosion by the glass. However, addition of Cr 2 O 3 also increases the tendency for formation of sulfate/chromate secondary phases and therefore such additions become increasingly undesirable as the ratio of sulfate to sodium in the LAW stream increases. Therefore, for such LAW streams, removal of Cr 2 O 3 as an additive could potentially increase sulfate loading in the LAW glasses, provided that K-3 refractory corrosion can be controlled by other means. The present work was directed towards developing LAW glasses with high alkali concentrations (> 24 wt%) without the use of Cr 2 O 3 as an additive. The results of the work clearly show that LAW glasses with high alkali concentrations that meet all of the WTP requirements, including K-3 refractory corrosion, can be formulated without the use of Cr 2 O 3 as an additive.