DEMONSTRATION OF THE GLYCOLIC-FORMIC FLOWSHEET IN THE SRNL SHIELDED CELLS USING ACTUAL WASTE

Lambert, D. ; Pareizs, J. ; Click, D.

关键词: CRITICALITY;    DISSOLUTION;    EVALUATION;    EVAPORATORS;    FISSILE MATERIALS;    FLOWSHEETS;    GLYCOLIC ACID;    IRON;    PLUTONIUM;    PROCESSING;    SAVANNAH RIVER PLANT;    SLUDGES;    SOLIDIFICATION;    SOLUBILITY;    STORAGE FACILITIES;    TANKS;    TESTING;    WASTE PROCESSING;    WASTES;   

DOI  :  10.2172/1030913
RP-ID  :  SRNL-STI-2011-00622
PID  :  OSTI ID: 1030913
Others  :  TRN: US1200071

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

Glycolic acid was effective at dissolving many metals, including iron, during processing with simulants. Criticality constraints take credit for the insolubility of iron during processing to prevent criticality of fissile materials. Testing with actual waste was needed to determine the extent of iron and fissile isotope dissolution during Chemical Process Cell (CPC) processing. The Alternate Reductant Project was initiated by the Savannah River Remediation (SRR) Company to explore options for the replacement of the nitric-formic flowsheet used for the CPC at the Defense Waste Processing Facility (DWPF). The goals of the Alternate Reductant Project are to reduce CPC cycle time, increase mass throughput of the facility, and reduce operational hazards. In order to achieve these goals, several different reductants were considered during initial evaluations conducted by Savannah River National Laboratory (SRNL). After review of the reductants by SRR, SRNL, and Energy Solutions (ES) Vitreous State Laboratory (VSL), two flowsheets were further developed in parallel. The two flowsheet options included a nitric-formic-glycolic flowsheet, and a nitric-formic-sugar flowsheet. As of July 2011, SRNL and ES/VSL have completed the initial flowsheet development work for the nitric-formic-glycolic flowsheet and nitric-formic-sugar flowsheet, respectively. On July 12th and July 13th, SRR conducted a Systems Engineering Evaluation (SEE) to down select the alternate reductant flowsheet. The SEE team selected the Formic-Glycolic Flowsheet for further development. Two risks were identified in SEE for expedited research. The first risk is related to iron and plutonium solubility during the CPC process with respect to criticality. Currently, DWPF credits iron as a poison for the fissile components of the sludge. Due to the high iron solubility observed during the flowsheet demonstrations with simulants, it was necessary to determine if the plutonium in the radioactive sludge slurry demonstrated the same behavior. The second risk is related to potential downstream impacts of glycolate on Tank Farm processes. The downstream impacts will be evaluated by a separate research team. Waste Solidification Engineering (WSE) has requested a radioactive demonstration of the Glycolic-Formic Flowsheet with radioactive sludge slurry be completed in the Shielded Cells Facility of the SRNL. The Shielded Cells demonstration only included a Sludge Receipt and Adjustment Tank (SRAT) cycle, and not a Slurry Mix Evaporator (SME) cycle or the co-processing of salt products. Sludge Batch 5 (SB5) slurry was used for the demonstration since it was readily available, had been previously characterized, and was generally representative of sludges being processing in DWPF. This sample was never used in the planned Shielded Cells Run 7 (SC-7).