Evaluation of isotope migration - land burial. Water chemistry at commercially operated low-level radioactive waste disposal sites. Quarterly progress report, April-June 1980

Abstract

This report presents the analytical results for tritium content of soil cores taken at the Barnwell, South Carolina, disposal site, field measurements at Barnwell, concentrations of free chelating agents in selected trench waters, and the analyses of water samples collected at the Maxey Flats, Kentucky, disposal site. Tritium contents in soil cores taken below the trenches show a decrease in tritium with depth to a minimum value at approximately ten meters, followed by an increase below this depth. This deeper maximum probably represents the downward movement of the previous years seasonal maxima for water infiltration into the trenches. This amount of downward migration from the trench bottom is approximately what would be expected based on the hydraulic conductivity of these sediments. Field measurements of trench waters at the Barnwell, South Carolina, disposal site indicate that the waters are chemically oxidizing regimes relative to those at Maxey Flats and West Valley. Analyses were performed to determine the amounts of free chelating agents DTPA, EDTA, and NTA in selected trenches at the Maxey Flats, West Valley, Barnwell, and Sheffield, disposal sites. Amounts of free chelating agents were generally below 1 ..mu..g/g, with one sample as high as 28 ..mu..g/g. No drastic changes in trench water compositions were observed relative to previous sampling at Maxey Flats. The experimental interceptor trenches contain detectable amounts of strontium and plutonium. Tritium contents vary from typical disposal trench levels (E7-E8 pCi/L) in trench IT-2E, downward four oders of magnitude in trench IT-5 in a decreasing trend along the line of experimental trenches.