Summary of Analytical Results from Samples Supporting Tank Closure Cesium Removal (TCCR) Batch 3 and Modeling Results for Cs Loading on CST

Taylor-Pashow, K.; Hang, T.; Nash, C. A.

doi:10.2172/1651106

Cited by 4 publications

(20 citation statements)

References 6 publications

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“…OLI Modeling indicates that the Batch 1 solution is supersaturated in aluminum and calcium and the Batch 1A solution is supersaturated in calcium and iron. Aluminum, calcium, and iron removal from solution were observed previously for the Batch 1 teabag CST samples [2] and calcium and iron removal were observed for the Batch 1A teabag CST samples [3]. Analysis of the laboratory Tank 10H equilibrium batch contact solutions prior to and after CST contact revealed complete calcium removal (within the measurement detection limit) from the waste during testing.…”

Section: Executive Summarysupporting

confidence: 73%

“…Within measurement limitations, calcium was completely removed from the supernate samples during CST contact, while aluminum concentrations were unchanged. The calcium concentrations in the Tank 10H solutions used for batch contact testing were approximately 50% of the concentrations reported previously [2,3] for the as-received samples (Batch 1 Ca: 9.5E-05 M; Batch 1A Ca: 7.1E-05 M) analyzed several weeks earlier. The Tank 10H Batch 1A solution used for equilibrium testing also contained no detectable iron (<2.7E-5 M), indicating that the iron had decreased by >50% relative to the as-received sample (5.0E-5 M Fe) due to precipitation during storage [3].…”

Section: Cst Batch Contact Test Resultsmentioning

confidence: 53%

“…ZAM-based cesium loading predictions are compared to the observed loading for the production batch in Figure ES-1, where significantly lower performance was observed than predicted by the model. Even lower cesium loading results (versus ZAM) were observed previously for the in-tank "teabag" batch contact samples [2,3].…”

Section: Executive Summarymentioning

confidence: 44%

“…Based on the gamma scan results and the original total Cs analysis reported previously [2,4], cesium distribution coefficients (Kd; Equation 1), % removal (Equation 2), and loading (mmol Cs + /g CST; Equation 3) values were calculated for each test sample. Results are provided in Table 3.…”

Section: Cst Batch Contact Test Resultsmentioning

confidence: 99%

“…Measurements of the projected maximum cesium loading on CST media from this waste supernate were conducted prior to TCCR processing using a "teabag" approach which involved contacting a small amount of CST solids (~0.1 g) with the large volume (>175,000 gallons) of Tank 10H radioactive waste supernate over a 10 day period. Cesium loading on the CST media within the teabags was 63-65% lower than ZAM isotherm model predictions for the waste compositions tested [2,3]. To explore the difference, traditional CST batch contact tests were conducted at the Savannah River National Laboratory (SRNL) under controlled conditions using three Tank 10H waste supernate samples collected prior to and after the addition of NaOH reagent.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

CST Batch Contact Equilibrium Testing of TCCR Tank 10H Batch 1 and 1A Waste Supernate Samples

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Section: Executive Summarysupporting

confidence: 73%

Section: Cst Batch Contact Test Resultsmentioning

confidence: 53%

Section: Executive Summarymentioning

confidence: 44%

Section: Cst Batch Contact Test Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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CST Batch Contact Equilibrium Testing of TCCR Tank 10H Batch 1 and 1A Waste Supernate Samples

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et al. 2019

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Cesium Removal Performance Comparisons of Crystalline Silicotitanate Media Batches with Savannah River Site Waste Simulant

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Summary of Results from November 2021 Qualification Samples for Tank Closure Cesium Removal 1A (TCCR 1A)

Taylor-Pashow¹

2022

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Savannah River Remediation (SRR) is currently operating the Tank Closure Cesium Removal 1A (TCCR 1A) process to remove 137 Cs from tank waste supernate using an ion exchange process. As part of that process, Savannah River National Laboratory (SRNL) receives and analyzes samples in support of the qualification of each batch to be processed. SRNL recently received supernate samples retrieved from Tank 10H as well as in-tank batch contact samples for characterization in support of qualifying Batch 1 for processing through the TCCR 1A unit. SRNL received and characterized two sets of dip samples -a preliminary set of samples collected from Tank 10H in July 2021 (one surface and two variable depth samples) and a batch qualification set collected from Tank 10H in November 2021 (one surface and one variable depth sample). In addition, a third set of samples were collected from Tank 10H (two variable depth) at the time the in-tank batch contact test vials were retrieved (10 days after the initial qualification samples were collected).The two depth samples collected from Tank 10H in July 2021 contained a small amount of fine, dark brown solids, while the surface sample did not contain any visible solids. The density of the surface sample was 2-4% lower than the depth sample filtrates. The sodium concentrations in the depth samples were about 12-13% higher than the surface sample, indicating some stratification within the tank. Analysis of the digested VDS samples showed that the dark brown solids observed were primarily Fe and Mn as indicated by the >2000% increase in concentration of these two elements in the digested slurries when compared to the filtrates. Ca was also observed in the digested slurry samples, where it had been below the detection limit in the filtrate samples. Consistent with the Na concentrations, the 137 Cs activity in the depth samples was higher than the surface sample (~21-22%).The qualification samples (one surface and one depth sample taken at 80") received in early November 2021 did not contain any significant solids; however, the depth sample appeared slightly hazy. There was a significant difference in the densities of the two samples (1.312 g/mL (0.35% RSD) and 1.387 g/mL(0.83% RSD) for the surface and VDS, respectively), and therefore the samples were not combined for analysis. Due to the difference in densities in these two samples, two additional depth samples were collected from the tank 10 days later; one at a depth of 90" and one at a depth of 80". These two samples also had significantly different densities (1.301 g/mL (0.46% RSD) versus 1.379 g/mL (0.46% RSD)) indicating stratification in the tank between these two depths. The remaining analyses on the original qualification samples were consistent with the density measurements, showing the salt solution was more concentrated at a depth of 80" compared to the surface. Based on these results, SRR recirculated the tank and repeated the qualification process. The results from the requalification will be documented in a separate report....

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Summary of Analytical Results from Samples Supporting Tank Closure Cesium Removal (TCCR) Batch 3 and Modeling Results for Cs Loading on CST

Cited by 4 publications

References 6 publications

CST Batch Contact Equilibrium Testing of TCCR Tank 10H Batch 1 and 1A Waste Supernate Samples

CST Batch Contact Equilibrium Testing of TCCR Tank 10H Batch 1 and 1A Waste Supernate Samples

Cesium Removal Performance Comparisons of Crystalline Silicotitanate Media Batches with Savannah River Site Waste Simulant

Summary of Results from November 2021 Qualification Samples for Tank Closure Cesium Removal 1A (TCCR 1A)

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