SYMPOSIA PAPER Published: 01 January 1989
STP22894S

Large-Scale Demonstration of Low-Level Waste Solidification in Saltstone

Source

The saltstone lysimeters are a large-scale demonstration of a disposal concept for decontaminated salt solution resulting from in-tank processing of defense waste. The lysimeter experiment has provided data on the leaching behavior of large saltstone monoliths under realistic field conditions. The results also will be used to compare the effect of capping the waste form on contaminant release.

Three saltstone lysimeters were installed in December 1983 and January 1984, each containing a buried monolith formed from 9500 L of decontaminated salt solution solidified with a blended cement. The decontaminated salt solution was produced using actual Savannah River Plant waste. One lysimeter has a gravel cap and another has a clay cap placed over the buried monolith. The monolith in the third lysimeter is uncapped. Each lysimeter has provision to collect leachate from a sump below the buried monolith and soil moisture samplers for gathering samples adjacent to the waste form.

Biweekly monitoring of sump leachate from all three lysimeters has continued on a routine basis for approximately three years. The uncapped lysimeter has shown the highest levels of nitrate and 99Tc release. The gravel-and-clay-capped lysimeters have shown levels equivalent to or slightly higher than background rainwater levels.

Mathematical model predictions are compared with lysimeter results and are applied to predict the impact of saltstone disposal on ground-water quality.

Author Information

McIntyre, PF
E. I. duPont de Nemours and Company, Marshall Labs, Philadelphia, PA
Oblath, SB
E. I. duPont de Nemours and Company, Savannah River Laboratory, Aiken, SC
Wilhite, EL
E. I. duPont de Nemours and Company, Savannah River Laboratory, Aiken, SC
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: D34
Pages: 392–403
DOI: 10.1520/STP22894S
ISBN-EB: 978-0-8031-5090-4
ISBN-13: 978-0-8031-1261-2