Download or read book SLUDGE BATCH 4 BASELINE MELT RATE FURNACE AND SLURRY FED MELT RATE FURNACE TESTS WITH FRITS 418 AND 510 U written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Several Slurry-Fed Melt Rate Furnace (SMRF) tests with earlier projections of the Sludge Batch 4 (SB4) composition have been performed. 1,2 The first SB4 SMRF test used Frits 418 and 320, however it was found after the test that the REDuction/OXidation (REDOX) correlation at that time did not have the proper oxidation state for manganese. Because the manganese level in the SB4 sludge was higher than previous sludge batches tested, the impact of the higher manganese oxidation state was greater. The glasses were highly oxidized and very foamy, and therefore the results were inconclusive. After resolving this REDOX issue, Frits 418, 425, and 503 were tested in the SMRF with the updated baseline SB4 projection. Based on dry-fed Melt Rate Furnace (MRF) tests and the above mentioned SMRF tests, two previous frit recommendations were made by the Savannah River National Laboratory (SRNL) for processing of SB4 in the Defense Waste Processing Facility (DWPF). The first was Frit 503 based on the June 2006 composition projections. 3 The recommendation was changed to Frit 418 as a result of the October 2006 composition projections (after the Tank 40 decant was implemented as part of the preparation plan). However, the start of SB4 processing was delayed due to the control room consolidation outage and the repair of the valve box in the Tank 51 to Tank 40 transfer line. These delays resulted in changes to the projected SB4 composition. Due to the slight change in composition and based on preliminary dry-fed MRF testing, SRNL believed that Frit 510 would increase throughput in processing SB4 in DWPF. Frit 418, which was used in processing Sludge Batch 3 (SB3), was a viable candidate and available in DWPF. Therefore, it was used during the initial SB4 processing. Due to the potential for higher melt rates with Frit 510, SMRF tests with the latest SB4 composition (1298 canisters) and Frits 510 and 418 were performed at a targeted waste loading (WL) of 35%. The '1298 canisters' describes the number of equivalent canisters that would be produced from the beginning of the current contract period before SB3 is blended with SB4. The melt rate for the SMRF SB4/Frit 510 test was 14.6 grams/minute. Due to cold cap mounding problems with the SMRF SB4/Frit 418 feed at 50 weight % solids that prevented a melt rate determination, this feed was diluted to 45 weight % solids. The melt rate for this diluted feed was 8.9 grams/minute. A correction factor of 1.2 for estimating the melt rate at 50 weight % solids from 45 weight % solids test results (based on previous SMRF testing5) was then used to estimate a melt rate of 10.7 grams/minute for SB4/Frit 418 at 50 weight % solids. Therefore, the use of Frit 510 versus Frit 418 with SB4 resulted in a higher melt rate (14.6 versus an estimated 10.7 grams/minute). For reference, a previous SMRF test with SB3/Frit 418 feed at 35% waste loading and 50 weight % solids resulted in a melt rate of 14.1 grams/minute. Therefore, depending on the actual feed rheology, the use of Frit 510 with SB4 could result in similar melt rates as experienced with SB3/Frit 418 feed in the DWPF.

Download or read book Sludge Batch 5 Slurry Fed Melt Rate Furnace Test with Frits 418 and 550 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on Melt Rate Furnace (MRF) testing for the Sludge Batch 5 (SB5) projected composition and assessments of the potential frits with reasonable operating windows, the Savannah River National Laboratory (SRNL) recommended Slurry Fed Melt Rate Furnace (SMRF) testing with Frits 418 and 550. DWPF is currently using Frit 418 with SB5 based on SRNL's recommendation due to its ability to accommodate significant sodium variation in the sludge composition. However, experience with high boron containing frits in DWPF indicated a potential advantage for Frit 550 might exist. Therefore, SRNL performed SMRF testing to assess Frit 550's potential advantages. The results of SMRF testing with SB5 simulant indicate that there is no appreciable difference in melt rate between Frit 418 and Frit 550 at a targeted 34 weight % waste loading. Both batches exhibited comparable behavior when delivered through the feed tube by the peristaltic pump. Limited observation of the cold cap during both runs showed no indication of major cold cap mounding. MRF testing, performed after the SMRF runs due to time constraints, with the same two Slurry Mix Evaporator (SME) dried products led to the same conclusion. Although visual observations of the cross-sectioned MRF beakers indicated differences in the appearance of the two systems, the measured melt rates were both (almost equal to)0.6 in/hr. Therefore, SRNL does not recommend a change from Frit 418 for the initial SB5 processing in DWPF. Once the actual SB5 composition is known and revised projections of SB5 after the neptunium stream addition and any decants is provided, SRNL will perform an additional compositional window assessment with Frit 418. If requested, SRNL can also include other potential frits in this assessment should processing of SB5 with Frit 418 result in less than desirable melter throughput in DWPF. The frits would then be subjected to melt rate testing at SRNL to determine any potential advantages.

Download or read book MELT RATE FURNACE TESTING FOR SLUDGE BATCH 5 FRIT OPTIMIZATION written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Savannah River National Laboratory (SRNL) was requested to provide the Defense Waste Processing Facility (DWPF) with a frit composition for Sludge Batch 5 (SB5) to optimize processing. A series of experiments were designed for testing in the Melt Rate Furnace (MRF). This dry fed tool can be used to quickly determine relative melt rates for a large number of candidate frit compositions and lead to a selection for further testing. Simulated Sludge Receipt and Adjustment Tank (SRAT) product was made according to the most recent SB5 sludge projections and a series of tests were conducted with frits that covered a range of boron and alkali ratios. Several frits with relatively large projected operating windows indicated melt rates that would not severely impact production. As seen with previous MRF testing, increasing the boron concentration had positive impacts on melt rate on the SB5 system. However, there appears to be maximum values for both boron and sodium above which the there is a negative effect on melt rate. Based on these data and compositional trends, Frit 418 and a specially designed frit (Frit 550) have been selected for additional melt rate testing. Frit 418 and Frit 550 will be run in the Slurry Fed Melt Rate Furnace (SMRF), which is capable of distinguishing rheological properties not detected by the MRF. Frit 418 will be used initially for SB5 processing in DWPF (given its robustness to compositional uncertainty). The Frit 418-SB5 system will provide a baseline from which potential melt rate advantages of Frit 550 can be gauged. The data from SMRF testing will be used to determine whether Frit 550 should be recommended for implementation in DWPF.

Download or read book Initial SB4 Melt Rate Furnace Testing U written by M. Smith and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Defense Waste Processing Facility (DWPF) is presently vitrifying Sludge Batch 3 (SB3) and preparing to process Sludge Batch 4 (SB4) in late 2006 or early 2007. The final composition of SB4 has not been finalized, as various blending and/or washing strategies are still being considered. SB4 will be comprised of the contents of Tanks 5, 6, 7, 8, and 11 (which will be transferred to Tank 51) along with plutonium and neptunium solutions from F and H Canyons, and possibly material from Tank 4. Tank 4 was originally included in projections, but plans have since changed (after completion of these tests) and Tank 4 is no longer part of SB4 due to problems with sludge removal. Even though the final SB4 composition was not finalized at the time of this study, there were 20 bounding options documented that could be used for preliminary melt rate tests. At the time of these tests, the SB4 compositions described as ''SB4 1200 canister baseline'' and ''SB4 1200 canister baseline (one less washed)'' documented elsewhere were chosen for these tests. The 1200 canister describes the number of equivalent canisters that would be produced from the beginning of the current contract period before SB3 is blended with SB4. These compositions were chosen as they had the highest amount of SB4 in the blend and were therefore considered as worse case SB4 feeds with regards to melt rate. This is because SB4 has higher alumina levels of any sludge batch yet processed and alumina has a negative impact on the DWPF melt rate. This baseline sludge includes Tank 4 but does not include auxiliary waste streams such as the Actinide Removal Process (ARP) stream, which contains monosodium titanate (MST), entrained sludge, and various soluble sodium compounds as the result of filter cleaning and stream adjustment for transfer. These preliminary dry-fed Melt Rate Furnace (MRF) tests were needed to initially evaluate melt rate/waste throughput. This study addressed SB4 with Frits 418 and 320, the impact of waste loading, the impact of the higher amount of Al in SB4, the amount of sludge washing, the possible addition of the ARP stream, the possible need to use a new frit to increase sulfur solubility, and the impact of the use of low Li frits to minimize the formation of an Al-Li-silicate phase that may be an intermediate reaction phase that could possibly hinder melt rate for SB4. For the SB4 sludge tested in the MRF for this preliminary work, the melt rate for SB4 simulant was lower than SB3. The higher alumina content in SB4 is probably the reason for the lower SB4 melt rate. Because the actual SB4 composition has not yet been finalized and may be different enough from the simulant SB4 sludges tested for these tests, the actual difference in melt rate for the two sludge batches cannot be projected. Therefore, further melt rate testing, including slurry testing in the Slurry-Fed Melt Rate Furnace (SMRF) will be needed as the SB4 compositions are further refined. Tests were performed with non-radioactive, simulated SB4 material. Due to the small-scale of the test equipment and the design of the equipment, as well as the use of dry, non-radioactive simulant feed, the behavior of the actual radioactive SB4 feed in the DWPF melter cannot be fully proven.

Download or read book MELT RATE TESTING FOR SLUDGE BATCH 6 written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Savannah River National Laboratory (SRNL) was requested to provide Savannah River Remediation (SRR) with a recommended frit composition for Sludge Batch 6 (SB6) to optimize processing at the Defense Waste Processing Facility (DWPF). This report discusses the results of a series of melt rate experiments that were completed in support of the frit recommendation and the preparation of the feed used in the testing. The objective of the work was to identify the impact of individual frit component concentrations on melt rate for both SB6 and for DWPF sludge batches in general. The dry fed, Melt Rate Furnace (MRF) was used to compare the relative melt rate performance of several candidate frit compositions. Sludge composition projection changes and variation led to the fabrication and testing of several new frits along with Frit 418, which is currently utilized at the DWPF for Sludge Batch 5 (SB5) processing. The melt rate testing results show that changes in the frit composition, such as increases in B2O3 or Li2O concentrations, can provide a faster melt rate for SB6 relative to Frit 418. However, the composition of SB6 as currently projected (February 2010 blended with a 40 inch heel of SB5) does not allow for significant changes in frit composition relative to Frit 418 without compromising the projected operating windows. Only one of the new frits tested, Frit IS7, remains viable for SB6 processing based on the current composition projections. The melt rate results also demonstrated that a low Na2O concentration frit (particularly Frit IS7) can provide reasonable melt rates if the concentrations of Li2O or B2O3 in the frit are increased. The measured melt rate for Frit IS7 with the simulated SB6 feed was about 15% faster than that for Frit 418. The projected operating windows for Frits 418 and IS7 are very similar with the current SB6 projections. However, waste loadings with Frit IS7 are limited by low viscosity predictions, while waste loadings with Frit 418 are limited by predictions of nepheline crystallization. It is recommended that SRNL reevaluate the final SB6 composition once washing and blending are complete to determine whether a change in frit composition could provide improved operating windows, improved sulfate solubility, and/or increased waste throughput.

Download or read book Feed Preparation for Source of Alkali Melt Rate Tests written by D. P. Lambert and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the Source of Alkali testing was to prepare feed for melt rate testing in order to determine the maximum melt-rate for a series of batches where the alkali was increased from 0% Na{sub 2}O in the frit (low washed sludge) to 16% Na{sub 2}O in the frit (highly washed sludge). This document summarizes the feed preparation for the Source of Alkali melt rate testing. The Source of Alkali melt rate results will be issued in a separate report. Five batches of Sludge Receipt and Adjustment Tank (SRAT) product and four batches of Slurry Mix Evaporator (SME) product were produced to support Source of Alkali (SOA) melt rate testing. Sludge Batch 3 (SB3) simulant and frit 418 were used as targets for the 8% Na{sub 2}O baseline run. For the other four cases (0% Na{sub 2}O, 4% Na{sub 2}O, 12% Na{sub 2}O, and 16% Na{sub 2}O in frit), special sludge and frit preparations were necessary. The sludge preparations mimicked washing of the SB3 baseline composition, while frit adjustments consisted of increasing or decreasing Na and then re-normalizing the remaining frit components. For all batches, the target glass compositions were identical. The five SRAT products were prepared for testing in the dry fed melt-rate furnace and the four SME products were prepared for the Slurry-fed Melt-Rate Furnace (SMRF). At the same time, the impacts of washing on a baseline composition from a Chemical Process Cell (CPC) perspective could also be investigated. Five process simulations (0% Na{sub 2}O in frit, 4% Na{sub 2}O in frit, 8% Na{sub 2}O in frit or baseline, 12% Na{sub 2}O in frit, and 16% Na{sub 2}O in frit) were completed in three identical 4-L apparatus to produce the five SRAT products. The SRAT products were later dried and combined with the complementary frits to produce identical glass compositions. All five batches were produced with identical processing steps, including off-gas measurement using online gas chromatographs. Two slurry-fed melter feed batches, a 4% Na{sub 2}O in frit run (less washed sludge combined with frit with less Na) and a 12% Na{sub 2}O in frit run (more washed sludge combined with frit with more Na), were produced for the SMRF targeting glasses that were identical in composition. These batches were duplicates of two smaller batches which were prepared for the dry fed melt-rate testing. Four process simulations were completed in two identical experimental 22-L apparatus to produce these two melter feed batches. Both melter feed batches were produced as planned. The targeted solids content for both batches was 50-wt%.

Download or read book The Impact of the Source of Alkali on Sludge Batch 3 Melt Rate U written by M. Smith and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous Savannah River National Laboratory (SRNL) melt rate tests in support of the Defense Waste Processing Facility (DWPF) have indicated that improvements in melt rate can be achieved through an increase in the total alkali of the melter feed. Higher alkali can be attained by the use of an ''underwashed'' sludge, a high alkali frit, or a combination of the two. Although the general trend between melt rate and total alkali (in particular Na{sub 2}O content) has been demonstrated, the question of ''does the source of alkali (SOA) matter?'' still exists. Therefore the purpose of this set of tests was to determine if the source of alkali (frit versus sludge) can impact melt rate. The general test concept was to transition from a Na{sub 2}O-rich frit to a Na{sub 2}O-deficient frit while compensating the Na{sub 2}O content in the sludge to maintain the same overall Na{sub 2}O content in the melter feed. Specifically, the strategy was to vary the amount of alkali in frits and in the sludge batch 3 (SB3) sludge simulant (midpoint or baseline feed was SB3/Frit 418 at 35% waste loading) so that the resultant feeds had the same final glass composition when vitrified. A set of SOA feeds using frits ranging from 0 to 16 weight % Na{sub 2}O (in 4% increments) was first tested in the Melt Rate Furnace (MRF) to determine if indeed there was an impact. The dry-fed MRF tests indicated that if the alkali is too depleted from either the sludge (16% Na{sub 2}O feed) or the frit (the 0% Na{sub 2}O feed), then melt rate was negatively impacted when compared to the baseline SB3/Frit 418 feed currently being processed at DWPF. The MRF melt rates for the 4 and 12% SOA feeds were similar to the baseline SB3/Frit 418 (8% SOA) feed. Due to this finding, a smaller subset of SOA feeds that could be processed in the DWPF (4 and 12% SOA feeds) was then tested in the Slurry-fed Melt Rate Furnace (SMRF). The results from a previous SMRF test with SB3/Frit 418 (Smith et al. 2004) were used as the SMRF melt rate of the baseline feed. The SOA SMRF test results agreed with those of the MRF tests for these two feeds as the melt rates were similar to the baseline SB3/Frit 418 feed. In other words, the source of alkali was close enough to the baseline feed as to not negatively impact melt rate. Based on these results, there appears to be an acceptable range of the source of alkali that results in the highest melt rate for a particular sludge batch. If, however, the alkali is too depleted from either the sludge or the frit, then melt rate will be lower. Although SB3 simulant sludge and Frit 418 were used for these tests, it was not the intent of these tests to determine an optimum source of alkali range for SB3. Rather, the findings of these tests should be used to help in the decision process for future sludge batch washing and/or blending strategies. The results, however, do confirm that the current processing of SB3 is being performed in the proper source of alkali range. Because all of this testing was performed on small-scale equipment with slurried, non-radioactive simulant, the exact impact of the source of alkali with SB3 in the DWPF melter could not be fully evaluated.

Download or read book The Impact of Feed Preparation Acid Stoichiometry and Redox on Melt Rate for the SB3 Frit 418 Feed System written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Batch 2 (SB2) and Sludge Batch 3 (SB3), and implemented a frit change from Frit 320 to Frit 418This blended sludge batch has been designated SB3 although previously SRNL has called this new sludge batch SB2/3. A series of dry-fed tests (using the Melt Rate Furnace or MRF) and slurry fed tests (using the Slurry-Fed Melt Rate Furnace or SMRF) have been performed to investigate the effect of feed preparation acid stoichiometry and REDOX (Reduction/Oxidation) on the melt rate of the SB3 - Frit 418 system. With regards to acid stoichiometry, the current DWPF target of 155 gave a higher melt rate than the 185 when tested in the SMRF. This contradicted the MRF results for the first time that both melt systems were used to evaluate melt rate with various feeds. The SMRF results should be used as slurry-fed results are more representative of what would occur in the DWPF, especially since the variable tested did not change the final glass composition. With regard to changes in REDOX (0.0, 0.1, a nd 0.2), the MRF tests indicated no difference while the SMRF tests showed that melt rate was not negatively impacted until a REDOX below 0.1 was used. In addition, all SMRF acid stoichiometry and REDOX feeds tested were diluted from about 50 to 45 weight percent total solids after melt rates had been determined at 50 weight percent. In all cases the lower weight percent solids resulted in lower melt rates. Based on this testing, the Immobilization Technology Section (ITS) recommends that the DWPF continue to operate the feed preparation processing for SB3 with Frit 418 with a targeted acid stoichiometry of 155 and a targeted REDOX of 0.2. If needed for other process concerns, REDOX targets approaching 0.1 could be used at DWPF before melt rate would be negatively impacted. Because all of this testing was performed on small-scale equipment with dried or slurred, nonradioactive simulant, the exact impact of feed acid stoichiometry and REDOX on the radioactive sludge in a DWPF-sized melter could not be quantified.

Download or read book An Assessment of the Sulfate Solubility Limit for the FRIT 418 Sludge Batch 2 written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this report is to establish a ''single point'' sulfate solubility limit or constraint for the Frit 418 - Sludge Batch 2/3 (SB2/3) system. Based on the results of this study, it is recommended that the glass limit in the Product Composition Control System (PCCS) for the Frit 418 - SB2/3 system be set at 0.60 wt%. The new limit has been set based solely on sealed crucible scale data and does not take credit or account for potential volatilization that may occur in the Defense Waste Processing Facility (DWPF) melter. Although the limit is established based on sealed crucible scale tests, supplementary testing using the Slurry-Fed Melt Rate Furnace (SMRF) provides a measure of confidence that applying the 0.6 wt% limit in PCCS will prevent the formation of a salt layer in the melter. The critical data point that was used to define the solubility limit for this system was from a ''spiked'' 30% waste loading (WL) glass targeting 0.65 wt%. The measured content in this glass was 0.62 wt%. Applying the Savannah River Technology Center - Mobile Laboratory (SRTCML) inductively coupled plasma (ICP) atomic emission spectroscopy (AES) uncertainties to establish a solubility limit for the Frit 418 - SB2/3 system of 0.60 wt% (in glass) provides a ''single point'' limit that covers the anticipated WL interval of interest. It is noted that there are glasses above the 0.60 wt% limit that were homogeneous, thus reinforcing the theory of a compositional effect on solubility within this specific system. In general, higher solubilities were observed at higher targeted waste loadings.

Download or read book PRELIMINARY FRIT DEVELOPMENT AND MELT RATE TESTING FOR SLUDGE BATCH 6 SB6 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Liquid Waste Organization (LWO) provided the Savannah River National Laboratory (SRNL) with a Sludge Batch 6 (SB6) composition projection in March 2009. Based on this projection, frit development efforts were undertaken to gain insight into compositional effects on the predicted and measured properties of the glass waste form and to gain insight into frit components that may lead to improved melt rate for SB6-like compositions. A series of Sludge Batch 6 (SB6) based glasses was selected, fabricated and characterized in this study to better understand the ability of frit compositions to accommodate uncertainty in the projected SB6 composition. Acceptable glasses (compositions where the Product Composition Control System (PCCS) Measurement Acceptability Region (MAR) predicted acceptable properties, good chemical durability was measured, and no detrimental nepheline crystallization was observed) can be made using Frit 418 with SB6 over a range of Na2O and Al2O3 concentrations. However, the ability to accommodate variation in the sludge composition limits the ability to utilize alternative frits for potential improvements in melt rate. Frit 535, which may offer improvements in melt rate due to its increased B2O3 concentration, produced acceptable glasses with the baseline SB6 composition at waste loadings of 34 and 42%. However, the PCCS MAR results showed that it is not as robust as Frit 418 in accommodating variation in the sludge composition. Preliminary melt rate testing was completed in the Melt Rate Furnace (MRF) with four candidate frits for SB6. These four frits were selected to evaluate the impacts of B2O3 and Na2O concentrations in the frit relative to those of Frit 418, although they are not necessarily candidates for SB6 vitrification. Higher concentrations of B2O3 in the frit relative to that of Frit 418 appeared to improve melt rate. However, when a higher concentration of B2O3 was coupled with a lower concentration of Na2O relative to Frit 418, melt rate did not appear to improve. It is expected that a SB6 composition projection with less uncertainty will be received during analysis of the Tank 51 E-1 sample, which will be pulled after the completion of aluminum dissolution in August 2009. At that time, additional frit development work will be performed to seek improved melt rates while maintaining viable projected operating windows. This later work will ultimately lead to a frit recommendation for SB6.

Download or read book Sludge Batch Decant No 5 Frit 202 Flowsheet Demonstration written by M. E. Smith and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report focuses on the first surrogate demonstration of a workable flowsheet for SB3 material. Two 15L glass Sludge Receipt and Adjustment Tank/Slurry Mix Evaporator (SRAT/SME) vessels at the Aiken County Technology Laboratory (ACTL) were used for the feed preparation portion of the test while the feed was vitrified in the ACTL Slurry-fed Melt Rate Furnace (SMRF). The flowsheet tested should not be considered final as further optimization is probable.

Download or read book QUARTZ MELT RATE FURNACE EVALUATION USING SLUDGE BATCH 3 FEED written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Quartz Melt Rate Furnace (QMRF) was developed to study the melt rate and offgas composition of simulated Defense Waste Processing Facility (DWPF) melter feed. The objective of this testing was to evaluate whether the apparatus could be used to study the offgas chemistry of melting batches and perform small-scale slurry-fed melt rate tests. The furnace was tested in three different configurations: a dry-fed test with offgas analysis, a slurry-fed test without offgas analysis, and a slurry-fed test with offgas analysis. During the dry-fed test, offgas composition was successfully measured throughout the run and total offgas flow was calculated from the helium tracer concentration. During the slurry-feeding tests without offgas analysis, the furnace exhibited stable feeding behavior with no problems with feed tube pluggage. Feeding behavior was used to measure the melt rate of Sludge Batch 3 with Frit 320 and with Frit 418. Both frits had approximately the same melt rate during the tests based on amount of melter feed added per minute. During the slurry-fed test with offgas analysis, spikes in the data prevented overall offgas flow analysis from the helium tracer, but the ratio of different offgas species allowed the composition data to be compared between runs. Minor improvements were identified that would enhance the performance of the furnace and further testing should be performed to optimize the performance of the apparatus. These tests should focus on increasing the stability of offgas composition data by providing more surge capacity in the offgas system, determining the sensitivity of the furnace to melt rate during slurry-fed tests and refining the lid heat power to optimize melt rate measurements, and to develop the capability to utilize the system with radioactive feeds.

Download or read book Frit Development Efforts for Sludge Batch 4 SB4 written by T. B. Edwards and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The model-based assessments of nominal Sludge Batch 4 (SB4) compositions suggest that a viable frit candidate does not appear to be a limiting factor as the Closure Business Unit (CBU) considers various tank blending options and/or washing strategies. This statement is based solely on the projected operating windows derived from model predictions and does not include assessments of SO{sub 4} solubility or melt rate issues. The viable frit candidates covered a range of Na{sub 2}O concentrations (from 8% to 13%--including Frit 418 and Frit 320) using a ''sliding Na{sub 2}O scale'' concept (i.e., 1% increase in Na{sub 2}O being balanced by a 1% reduction in SiO{sub 2}) which effectively balances the alkali content of the incoming sludge with that in the frit to maintain and/or increase the projected operating window size while potentially leading to improved melt rate and/or waste loadings. This strategy or approach allows alternative tank blending strategies and/or different washing scenarios to be considered and accounted for in an effective manner without wholesale changes to the frit composition. In terms of projected operating windows, in general, the sludge/frit systems evaluated resulted in waste loading intervals from 25 to the mid-40%'s or even the mid-50%'s. The results suggest that a single frit could be selected for use with all 20 options which indicates some degree of frit robustness with respect to sludge compositional variation. In fact, use of Frit 418 or Frit 320 (the ''cornerstone'' frits given previous processing experience in the Defense Waste Processing Facility (DWPF)) are plausible for most (if not all) options being considered. However, the frit selection process also needs to consider potential processing issues such as melt rate. Based on historical trends between melt rate and total alkali content, one may elect to use the frit with the highest alkali content that still yields an acceptable operating window. However, other constraints may restrict access to higher waste loading or the proposed blending option being considered (e.g., sulfate content of the high-level waste and/or Chemical Processing Cell (CPC) issues may necessitate a more-washed sludge).

Download or read book DWPF Macrobatch 2 Melt Rate Tests written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Defense Waste Processing Facility (DWPF) canister production rate must be increased to meet canister production goals. Although a number of factors exist that could potentially increase melt rate, this study focused on two: (1) changes in frit composition and (2) changes to the feed preparation process to alter the redox of the melter feed. These two factors were investigated for Macrobatch 2 (sludge batch 1B) utilizing crucible studies and a specially designed ''melt rate'' furnace. Other potential factors that could increase melt rate include: mechanical mixing via stirring or the use of bubblers, changing the power skewing to redistribute the power input to the melter, and elimination of heat loss (e.g. air in leakage). The melt rate testing in FY00 demonstrated that melt rate can be improved by adding a different frit or producing a much more reducing glass by the addition of sugar as a reductant. The frit that melted the fastest in the melt rate testing was Frit 165. A paper stud y was performed using the Product Composition Control System (PCCS) to determine the impact on predicted glass viscosity, liquidus, durability, and operating window if the frit was changed from Frit 200 to Frit 165. PCCS indicated that the window was very similar for both frits. In addition, the predicted viscosity of the frit 165 glass was 46 poise versus 84 poise for the Frit 200 glass. As a result, a change from Frit 200 to Frit 165 is expected to increase the melt rate in DWPF without decreasing waste loading.

Download or read book SLUDGE BATCH 4 SB4 AFTER A TANK 40 DECANT written by T. Tommy Edwards and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In early October 2006, the Liquid Waste Organization (LWO) began to consider decanting Tank 40 at the end of Sludge Batch 3 (SB3) processing and transferring the aqueous phase from the decant to Tank 51. This transfer would be done to decrease Tank 51 yield stress and facilitate the transfer of the contents of Tank 51 to Tank 40. The projected composition of Sludge Batch 4 (SB4) was adjusted by LWO to reflect the impact of the Tank 40 decant leading to new projected compositions for SB4, designated as the 10-04-06 and the 10-10-06 compositions. A comparison between these SB4 compositions and those provided in June 2006 indicates that the new compositions are slightly higher in Al2O3, Fe2O3, and U3O8 and slightly lower in SiO2. The most dramatic change, however, is the new projection's Na2O concentration, which is more than 4.5 wt% lower than the June 2006 projection. This is a significant change due to the frit development team's approach of aligning the Na2O concentration in a candidate frit to the Na2O content of the sludge. This approach enhances the projected operating window and the waste throughput potential for the resulting glass system while eliminating the potential for nepheline crystallization. Nepheline can have a detrimental impact on durability. Questions surfaced regarding the applicability of Frit 503 to these revised compositions since the Savannah River National Laboratory (SRNL) recommended Frit 503 for use with SB4 based on the June 2006 compositional projection without the Tank 40 decant. Based on the paper study assessments, the change in SB4's expected Na2O content had a significant, negative impact on the projected operating window for the Frit 503/SB4 glass system. While Frit 418 had slightly smaller waste loading (WL) intervals for the June 2006 SB4 projections as compared to Frit 503 and the Frit 418 glass systems were nepheline limited, Frit 418 had a slightly larger operating window for the 10-04-06 projection (as compared to Frit 503) and the Frit 418/10-04-06 glass system was no longer nepheline limited. Thus, strictly from the perspective of this paper study, Frit 418 was more attractive than Frit 503 for the new SB4 projected compositions. This comparison, however, does not reflect other aspects of interest for the glass systems such as their respective melt rates or the development of alternative frits to balance the projected operating windows, melt rate, waste throughput, and robustness to compositional variation. In discussions with Waste Solidification Engineering (WS-E) regarding the results being presented in this report, their decision was to utilize Frit 418 for initial processing of SB4. This decision was not only based on the paper study assessments presented in this report, but also on the fact that Frit 418 is currently being used to process SB3 and, perhaps more importantly, frit optimization efforts for SB4 may be premature given the uncertainties in tank transfer and heel volumes associated with the SB4 flowsheet. More specifically, WS-E indicated their plan to initiate processing with Frit 418 with subsequent authorization for the frit development team to optimize a frit based on the measured composition of SB4 after determination of the actual SB4 blend composition (i.e., both the SB3 and SB4 compositions and masses are known). Given this decision and recognizing that a SB4/Frit 503 variability study had been initiated as part of the qualification process, questions regarding the need for a supplemental variability study to demonstrate applicability of the process control models for a Frit 418 based system surfaced. This report addresses the need for a supplemental study and defines additional glasses to fill the compositional gaps. A total of 13 glasses (based on the 10-10-06 projection) were selected for the supplemental SB4/Frit 418 variability study. These glasses will be batched and melted following standard SRNL procedures, and a suite of characterization testing will be completed to measure the chemical durability of each glass composition.

Download or read book M moire contenant les raisons pour lesquelles il est tr s important de ne pas retirer le s minaire de Li ge des mains des Th ologiens S culiers et de n en pas donner la conduite aux P res J suites written by and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Explanation of the Differences in Length and Voicing of Consonants in French and English written by James L.. Barker and published by . This book was released on 1929 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: