Analyses by the Defense Waste Processing Facility Laboratory of Thorium Glasses from the Sludge Batch 6 Variability Study

The Savannah River Remediation (SRR) Defense Waste Processing Facility (DWPF) is currently processing Sludge Batch 6 (SB6) with Frit 418. At times during the processing of this glass system, thorium is expected to be at concentrations in the final wasteform that make it a reportable element for the first time since startup of radioactive operations at the DWPF. The Savannah River National Laboratory (SRNL) supported the qualification of the processing of this glass system at the DWPF. A recommendation from the SRNL studies was the need for the DWPF Laboratory to establish a method to measure thorium by Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICPAES). This recommendation led to the set of thorium-bearing glasses from the SB6 Variability Study (VS) being submitted to the DWPF Laboratory for chemical composition measurement. The measurements were conducted by the DWPF Laboratory using the sodium peroxide fusion preparation method routinely employed for analysis of samples from the Slurry Mix Evaporator (SME). These measurements are presented and reviewed in this report. The review indicates that the measurements provided by the DWPF Laboratory are comparable to those provided by Analytical Development's laboratory at SRNL for these same glasses. As a result, the authors of this report recommend that the DWPF Laboratory begin using its routine peroxide fusion dissolution method for the measurement of thorium in SME samples of SB6. The purpose of this technical report is to present the measurements generated by the DWPF Laboratory for the SB6 VS glasses and to compare the measurements to the targeted compositions for these VS glasses as well as to SRNL's measurements (both sets, targeted and measured, of compositional values were reported by SRNL in [2]). The goal of these comparisons is to provide information that will lead to the qualification of peroxide fusion dissolution as a method for the measurement by the DWPF Laboratory of thorium in SME glass samples