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Title: ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE

Abstract

Effluent streams from the Modular Caustic-Side Solvent Extraction Unit (MCU) will transfer to the tank farms and to the Defense Waste Processing Facility (DWPF). These streams will contain entrained solvent. A significant portion of the Strip Effluent (SE) pipeline (i.e., acid stream containing Isopar{reg_sign} L residues) length is within one inch of a sludge stream. Personnel envisioned the sludge stream temperature may reach 100 C during operation. The nearby SE stream may receive heat from the sludge stream and reach temperatures that may lead to flammability issues once the contents of the SE stream discharge into a larger reservoir. To this end, personnel used correlations from the literature to estimate the maximum temperature rise the SE stream may experience if the nearby sludge stream reaches boiling temperature. Several calculation methods were used to determine the temperature rise of the SE stream. One method considered a heat balance equation under steady state that employed correlation functions to estimate heat transfer rate. This method showed the maximum temperature of the acid stream (SE) may exceed 45 C when the nearby sludge stream is 80 C or higher. A second method used an effectiveness calculation used to predict the heat transfer rate inmore » single pass heat exchanger. By envisioning the acid and sludge pipes as a parallel flow pipe-to-pipe heat exchanger, this method provides a conservative estimation of the maximum temperature rise. Assuming the contact area (i.e., the area over which the heat transfer occurs) is the whole pipe area, the results found by this method nearly matched the results found with the previous calculation method. It is recommended that the sludge stream be maintained below 80 C to minimize a flammable vapor hazard from occurring.« less

Authors:
; ;
Publication Date:
Research Org.:
SRS
Sponsoring Org.:
USDOE
OSTI Identifier:
917511
Report Number(s):
WSRC-STI-2007-00276
TRN: US0805017
DOE Contract Number:
DE-AC09-96SR18500
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; VAPORS; FLAMMABILITY; HEAT TRANSFER; PIPELINES; SLUDGES; SOLVENT EXTRACTION; STORAGE FACILITIES; RADIOACTIVE WASTE PROCESSING; INORGANIC ACIDS

Citation Formats

Fondeur, F, Michael Poirier, M, and Samuel Fink, S. ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE. United States: N. p., 2007. Web. doi:10.2172/917511.
Fondeur, F, Michael Poirier, M, & Samuel Fink, S. ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE. United States. doi:10.2172/917511.
Fondeur, F, Michael Poirier, M, and Samuel Fink, S. Thu . "ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE". United States. doi:10.2172/917511. https://www.osti.gov/servlets/purl/917511.
@article{osti_917511,
title = {ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE},
author = {Fondeur, F and Michael Poirier, M and Samuel Fink, S},
abstractNote = {Effluent streams from the Modular Caustic-Side Solvent Extraction Unit (MCU) will transfer to the tank farms and to the Defense Waste Processing Facility (DWPF). These streams will contain entrained solvent. A significant portion of the Strip Effluent (SE) pipeline (i.e., acid stream containing Isopar{reg_sign} L residues) length is within one inch of a sludge stream. Personnel envisioned the sludge stream temperature may reach 100 C during operation. The nearby SE stream may receive heat from the sludge stream and reach temperatures that may lead to flammability issues once the contents of the SE stream discharge into a larger reservoir. To this end, personnel used correlations from the literature to estimate the maximum temperature rise the SE stream may experience if the nearby sludge stream reaches boiling temperature. Several calculation methods were used to determine the temperature rise of the SE stream. One method considered a heat balance equation under steady state that employed correlation functions to estimate heat transfer rate. This method showed the maximum temperature of the acid stream (SE) may exceed 45 C when the nearby sludge stream is 80 C or higher. A second method used an effectiveness calculation used to predict the heat transfer rate in single pass heat exchanger. By envisioning the acid and sludge pipes as a parallel flow pipe-to-pipe heat exchanger, this method provides a conservative estimation of the maximum temperature rise. Assuming the contact area (i.e., the area over which the heat transfer occurs) is the whole pipe area, the results found by this method nearly matched the results found with the previous calculation method. It is recommended that the sludge stream be maintained below 80 C to minimize a flammable vapor hazard from occurring.},
doi = {10.2172/917511},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jul 12 00:00:00 EDT 2007},
month = {Thu Jul 12 00:00:00 EDT 2007}
}

Technical Report:

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  • Two facilities for treating the salt currently being stored in the High Level Waste (HLW) tanks are currently planned to begin operations during the processing of Sludge Batch 4 (SB4). The Immobilization Technology Section (ITS) of the Savannah River National Laboratory (SRNL) was requested by the Defense Waste Processing Facility (DWPF) via Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 (Washburn, 2004) to evaluate the impacts on DWPF processing for streams from the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Side Extraction (CSSX) Unit (MCU). In particular, the TTR requests SRNL to validate the existing process flowsheet and establish amore » coupled operations flowsheet for use with SB4. The flowsheet runs are required so an evaluation of potential chemical processing issues, quantification of the potential hydrogen generation rates, and estimation of the required acid stoichiometry can be made. Previous testing (Baich et. al., 2003) was performed for incorporating ARP/MST in Sludge Batch 3 (SB3) and recommendations were made to DWPF on possible flowsheet options. However, since that time, some changes have occurred to the ARP facility processing strategy, and material balances have been revised (Subosits, 2004). Thus, testing with updated compositions was necessary. Since the MCU is a new design and project, no CPC flowsheet studies have been performed for this stream. This testing will validate the previously recommended ARP stream addition methods based on the new information and based on the need to also incorporate the MCU stream. The basic principle of solvent extraction is to use a sparingly soluble diluent material that carries an extractant that will complex with the cesium ions in the caustic HLW solution. The decontaminated aqueous stream (raffinate) is then sent to Saltstone for disposal. The cesium contained in the organic phase (solvent) can then be stripped into an aqueous phase ready for transfer to the DWPF. The solvent is then recycled.« less
  • Savannah River National Laboratory (SRNL) analyzed solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-11-314, MCU-11-315, MCU-11-316, MCU-11-317, MCU-11-318 and MCU-11-319 are reported. The results show that the solvent at MCU does not require an Isopar{reg_sign} L addition, but it will require addition of trioctylamine. Cesium mass transfer testing with the solvent matches expected extraction behavior but shows a slightly lower stripping efficiency than seen in the original processmore » demonstration for Macrobatch 3. The entrained aqueous solution indicates the scrub wash is significantly out of specification. As a result, the facility replaced the scrub wash. Unlike the previous solvent sample results, these analyses indicate that the solvent does not require minor Isopar{reg_sign} L trimming at this time. However, addition of TOA is warranted. These findings indicate that the new protocols for solvent monitoring and control are yielding favorable results. Nevertheless, the deviation in the TOA concentration since the last analysis indicates continued periodic (i.e., quarterly) monitoring is recommended. The {sup 137}Cs mass transfer results from the solvent sample testing show possible evidence of slightly reduced stripping efficiency. An evaluation (using a model) of expected system performance for MCU using the measured distribution values predicts an {approx}50% decline in DFs given the ESS test results. The customer should consider pulling a SHT sample for reanalysis.« less
  • Savannah River National Laboratory (SRNL) periodically analyses solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-11-314, MCU-11-315, MCU-11-316, MCU-11-317, MCU-11-318 and MCU-11-319 have been previously reported. MCU has experienced a modest decline in cesium removal efficiency while processing the current feed, 'Macrobatch 3'. While the target decontamination factor (DF) is 200, the fiscal year 2011 DF average is 161. The results of the prior solvent analysis report did notmore » identify a specific factor that would correlate with the poor cesium decontamination beyond a low concentration of the suppressor, trioctylamine. New analyses of the quarterly sample are reported in this document, as well as a cross-check of {sup 137}Cs measurements for SRNL and F/H lab. Furthermore, in an attempt to discover the reason for the decline in DF at MCU, SRNL was tasked with analyzing numerous Caustic Wash Tank (CWT) and chemical feed samples.« less
  • Solvent Hold Tank (SHT) samples are sent to Savannah River National Laboratory (SRNL) to examine solvent composition changes over time. On December 5, 2011, Operations personnel delivered six samples from the SHT (MCU-11-1452 through -1457) for analysis. These samples are intended to verify that the solvent is within the specified composition range. The results from the analyses are presented in this document. Samples were received in p-nut vials containing {approx}10 mL each. Once taken into the Shielded Cells, the samples were combined. Samples were removed for analysis by density, semi-volatile organic analysis (SVOA), high performance liquid chromatography (HPLC), and Fourier-Transformmore » Infra-Red spectroscopy (FTIR). Details for the work are contained in a controlled laboratory notebook. Each of the six p-nut vials contained a single phase, with no apparent solids contamination or cloudiness. Table 1 contains the results of the analyses for the combined samples. A duplicate density measurement of the organic phase gave a result of 0.844 g/mL (1.2% residual standard deviation - RSD). Using the density as a starting point, we know that the Isopar{reg_sign} L should be slightly higher than nominal and the other components should be slightly lower than nominal. The results as a whole are internally consistent. All measurements indicate Isopar{reg_sign} L higher than nominal, and Modifier lower than nominal. The extractant result is higher than expected - given the other results, the extractant concentration should be under nominal values. Using the measured density as well as the Isopar{reg_sign} L and Modifier concentrations from the FTIR results, we calculate an extractant concentration of 6888 mg/L. This value is outside the analytical uncertainty of the reported HPLC value. Given the other results, this most likely indicates that the HPLC extractant result was biased high. When compared to the MCU density target of 0.845 g/mL, there is no need to add an Isopar{reg_sign} L trim. However, it is advisable to add sufficient trioctylamine (TOA) to return the solvent composition to within specifications as that component has declined to about 64% the concentration since the last analysis. The TOA measurement was performed twice, so the result is not an analytical aberration. TOA has not been added to the system since the previous quarterly sample in October 2011. As with the previous solvent sample results, these analyses indicate that the solvent does not require Isopar{reg_sign} L trimming at this time. However, addition of TOA is warranted. These findings indicate that the new protocols for solvent monitoring and control are yielding favorable results. Nevertheless, the deviation in the TOA concentration since the last analysis indicates continued periodic (i.e., quarterly) monitoring is recommended.« less
  • Savannah River National Laboratory (SRNL) analyzed solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-12-488, MCU-12-489, MCU-12-490, MCU-12-491, MCU-12-492 and MCU-12-493 received 24 October 2012 are reported. The results show that the solvent at MCU does not require an Isopar® L addition, but it will require addition of trioctylamine. SRNL also analyzed the SHT sample for {sup 137}Cs content and determined the measured value is within tolerance but ismore » trending upward compared to the {sup 137}Cs measurement made last year.« less