SME Acceptability Determination For DWPF Process Control (U)

Abstract

Savannah River Site (SRS) since the start of radioactive operations in 1996. The author of this revision to the document gratefully acknowledges the firm technical foundation that Brown and Postles established to support the ongoing successful operation at the DWPF. Their integration of the glass propertycomposition models, developed under the direction of C. M. Jantzen, into a coherent and robust control system, has served the DWPF well over the last 20 + years, even as new challenges, such as the introduction into the DWPF flowsheet of auxiliary streams from the Actinide Removal Process (ARP) and other processes, were met.

Basic Research Needs for Environmental Management

“…Waste glass melters, including those at the Savannah River and Hanford Sites, are operated in a way to avoid salt accumulation. Avoiding salt formation in the melters is currently accomplished using conservative empirical limits on sulfur (often tabulated as trioxide) and in some cases also chromium and halides (Edwards et al 2006;Kim and Vienna 2012;Vienna and Kim 2014).…”

“…The airlift pour spout is the riser pipe that begins at the glass discharge spout indicated on Figure 7; however, it is not currently known how much of each type of crystal can be tolerated in a melter without causing processing problems or limiting the melter lifetime. A conservative limit on crystallinity was adopted by the DWPF that the liquidus temperature (T L) must be less than 1050°C to avoid any crystals (noble metals and their oxides excluded) in the melter (Edwards et al 2006;Fox et al 2014). WTP has constrained the glass composition to produce less than 1 volume percent of crystals at 950°C (Vienna and Kim 2014).…”

Characterization Results of SRS Tank 26 Samples FTF-26-19-12 and -13

“…Because a significant portion of the sulfur is insoluble in the sample, sulfur removal predictions during washing are difficult. It is possible that a portion of the sulfur in the insoluble solids is burkeite, and should dissolve during Tank Farm washing in the time periods between water additions and decants (see for example work with Tank 4 7 ). In burkeite, the sodium to sulfur ratio is 3:1.…”

Evaluation of a Material Balance Only and Material Balance with Real-Time In-line Monitoring Approaches for DFLAW Processing

“…Material balances are used for at least a portion of the waste reporting requirements in both the HLW 22 and LAW processes. Material balances based on the qualification samples results are used for reporting of the radionuclides for HLW processing and after an initial period of analysis, process knowledge is used for metal species during acid addition calculations for HLW sludge pretreatment.…”