Composition Measurements of the LAW HPVR Glasses

Abstract

This report provides the results from the chemical analyses of the glass compositions of the Low-Activity Waste High PCT and VHT Response study glasses, a series of simulated nuclear waste glasses designed and fabricated at Pacific Northwest National Laboratory. These data will be used in the development, validation, and implementation of enhanced property/composition models for waste glass vitrification at Hanford. Chemical analyses were performed on a representative sample of each of the quenched glasses to allow for comparisons with targeted compositions. The relative differences between the targeted and measured concentrations of Cl -, K2O, Na2O, and ZrO2 for several of the glasses were greater than 10%. These results can be used in further characterization of this series of glasses, including the normalization of Product Consistency Test results.

Product Consistency Test Results for the LAW HPVR Glasses

“…The PCT leachate samples were analyzed by inductively coupled plasma -optical emission spectroscopy (ICP-OES) 7 according to three analytical study plans designed to statistically randomize the measurements. [8][9][10] High purity multi-element custom ICP solution standards c (std) were prepared at SRNL and included in the analytical study plan as a check of the accuracy of the instrument used for these measurements. The analytical measurements were adjusted based on the dilution provided by PNNL.…”

“…Normalized elemental release values were calculated for each glass based on the target and measured 11 glass compositions.…”

“…d NCi was computed using both the targeted and average measured compositions. 11 NCi values were calculated using the units of measurement provided with the analytical results for this study. To accommodate the triplicate leachate measurements for each of the study glasses, the common logarithm of the normalized concentration for each element "i" (NCi) for each of the study glasses was determined using the equation:…”

“…where NCi remains in units of gwaste form/Lleachant, 10 log i c is the average of the common logarithms of the measured concentrations of element "i" in the triplicate leachates in units of mg/L (corrected for the dilutions performed at PNNL as discussed in Section 3.1), and 10 log i f is either the common logarithm of the targeted concentration of element "i" in the glass in units of weight percent (wt.%) or the common logarithm of the average measured concentration of element "i" in the glass in units of wt.% (reported previously 11 ). Note that the symbols in this second equation were kept consistent with those used in ASTM C1285, 6 but the units of measurement differ.…”

Characterization of the Sulfur-Saturated Melt Versions of the LAW HPVR Glasses

“…Characterization of the baseline glasses were reported earlier. 6 Samples of each of the SSM versions of the study glasses, along with samples of the wash solutions resulting from the preparation of each of the SSM glasses, were received at SRNL for chemical composition analysis. The PNNL identifiers (IDs) for the glass samples and associated SRNL sample identifiers are listed in Table 2-1.…”