Late Wash Cross-Flow Filter Organic Balance

A recent DOE-Savannah River review of the results and data from the Late Washing Crossflow Fitter assessment identified the fate of biphenyl as a concern in the Late Washing material balance. The concern arose because after the late washing operation only about 40% of the biphenyl remained in the irradiated precipitate and analyses of the spent wash water stream did not account for the missing biphenyl [2]. This document summarizes the results of subsequent filtration studies on the behavior and fate of all known organic precipitate feed components including biphenyl. The study employed a statistically designed material balance across a laboratory crossflow fitter. Data from two separate experiments are presented here. Results of the first study indicated no statistically significant loss of biphenyl, diphenylmercury, 0-terphenyl, diphenylamine, or aniline. Results did indicate minor losses of phenylboric acid, M-terphenyl, P-terphenyl, and a significant production of phenol, believed to be due to the way in which the experiment was performed. A second experiment demonstrated no statistically significant lose of any of the organic compounds

Am/Cm Canister Temperature Evaluation in Cim5

To facilitate the evaluation of alternate canister designs, 2 canisters were outfitted with thermocouples at elevations of 1/2, 3 1/2, and 6 1/2 inches from the canister bottom. The canisters were fabricated from two inch diameter schedule 10 and two inch diameter schedule 40 stainless steel pipe. Each canister was filled with approximately 2 kilograms of 49 wt percent lanthanide (Ln) loaded 25SrABS glass during 5 inch Cylindrical Induction Melter (CIM5) runs for TTR Tasks 3.03 and 4.03. Melter temperature, total mass of glass poured, and the glass pour rates were almost identical in both runs. The schedule 40 canister has a slightly smaller ID compared to the schedule 10 canister and therefore filled to a level of 9.5 inches compared to 8.0 inches for the schedule 40 canister. The schedule 40 canister had an empty mass of 1906 grams compared to 919 grams for the schedule 10 canister. The schedule 10 canister was found to have a higher maximum surface temperature by about 50--100 C (depending on height) during the glass pour compared to the schedule 40 canister. The additional thermal mass of the schedule 40 canister accounts for this difference. Once filled with glass, each of the canisters cooled at about the same rate, taking about an hour to cool below a maximum surface temperature of 200 C. No significant deformation of the either of the canisters was visually observed

Effect of Mercury-Noble Metal Interactions on SRAT Processing of SB3 Simulants (U)

Controlling hydrogen generation below the Defense Waste Processing Facility (DWPF) safety basis constrains the range of allowable acid additions in the DWPF Chemical Processing Cell. This range is evaluated in simulant tests at the Savannah River National Laboratory (SRNL). A minimum range of allowable acid additions is needed to provide operational flexibility and to handle typical uncertainties in process and analytical measurements used to set acid additions during processing. The range of allowable acid additions is a function of the composition of the feed to DWPF. Feed changes that lead to a smaller range of allowable acid additions have the potential to impact decisions related to wash endpoint control of DWPF feed composition and to the introduction of secondary waste streams into DWPF. A limited program was initiated in SRNL in 2001 to study the issue of hydrogen generation. The program was reinitiated at the end of fiscal year 2004. The primary motivation for the study is that a real potential exists to reduce the conservatism in the range of allowable acid additions in DWPF. Increasing the allowable range of acid additions can allow decisions on the sludge wash endpoint or the introduction of secondary waste streams to DWPF to be based on other constraints such as glass properties, organic carbon in the melter off-gas, etc. The initial phase of the study consisted of a review of site reports and off-site literature related to catalytic hydrogen generation from formic acid and/or formate salts by noble metals. Many things are already known about hydrogen generation during waste processing. This phase also included the development of an experimental program to improve the understanding of hydrogen generation. This phase is being documented in WSRC-TR-2002-00034. A number of areas were identified where an improved understanding would be beneficial. A phased approach was developed for new experimental studies related to hydrogen generation. The first phase of new experimental work consisted of six simulations of the DWPF Sludge Receipt and Adjustment Tank (SRAT). This phase had four objectives, but the primary focus was on the effect of mercury on hydrogen generation and SRAT processing. These objectives were to: (1) Obtain SRAT processing data at three different mercury concentrations. (2) Obtain comparable data for mercury added as HgO or as Hg(NO{sub 3}){sub 2}. (3) Obtain process data that could lead to more prototypical performance of the experimental equipment. (4) Use data from enhanced gas chromatographs to improve the understanding of acid consumption during processing

ILL best practices: streamlining & greening

This program will provide ILL practitioners with ideas to help them streamline and green their operations. Key topics to be discussed will include streamlining with technology by using features of WorldCat Resource Sharing, Odyssey standalone, Article Exchange, etc.; streamlining manual workflows within IN-Share and Evergreen libraries and reducing waste in ILL by greening the process

Review of Catalytic Hydrogen Generation in the DWPF Chemical Processing Cell, Part II

The Savannah River National Laboratory is in the process of investigating factors suspected of impacting catalytic hydrogen generation in the Defense Waste Processing Facility, DWPF, Chemical Process Cell, CPC. Noble metal catalyzed hydrogen generation in simulation work constrains the allowable acid addition operating window in DWPF. This constraint potentially impacts washing strategies during sludge batch preparation. It can also influence decisions related to the addition of secondary waste streams to a sludge batch. Catalytic hydrogen generation data from 2002-2005 were reviewed. The data came from process simulations of the DWPF Sludge Receipt and Adjustment Tank, SRAT, and Slurry Mix Evaporator, SME. Most of the data was from the development work for the Sludge Batch 3 process flowsheet. This included simulant and radioactive waste testing. Preliminary Sludge Batch 4 data were also reviewed. A statistical analysis of SB3 simulant hydrogen generation data was performed. One factor considered in the statistical analysis was excess acid. Excess acid was determined experimentally as the acid added beyond that required to achieve satisfactory nitrite destruction

Sodium Iodate Selectively Injuries the Posterior Pole of the Retina in a Dose-Dependent Manner: Morphological and Electrophysiological Study

Sequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20 mg/kg) of sodium iodate (NaIO3) were analyzed. Retinal morphology, apoptosis (TUNEL assay), and function (electroretinography; ERG) were examined at several time points after NaIO3 administration. The higher dose of NaIO3 caused progressive degeneration of the whole retinal area and total suppression of scotopic and photopic ERG. In contrast, the lower dose induced much less severe degeneration in peripheral part of retina along with a moderate decline of b- and a-wave amplitudes in ERG, corroborating the presence of regions within retina that retain their function. The peak of photoreceptor apoptosis was found on the 3rd day, but the lower dose induced more intense reaction within the central retina than in its peripheral region. In conclusion, these results indicate that peripheral area of the retina reveals better resistance to NaIO3 injury than its central part

Cytosolic NADPH balancing in Penicillium chrysogenum cultivated on mixtures of glucose and ethanol

The in vivo flux through the oxidative branch of the pentose phosphate pathway (oxPPP) in Penicillium chrysogenum was determined during growth in glucose/ethanol carbon-limited chemostat cultures, at the same growth rate. Non-stationary 13C flux analysis was used to measure the oxPPP flux. A nearly constant oxPPP flux was found for all glucose/ethanol ratios studied. This indicates that the cytosolic NADPH supply is independent of the amount of assimilated ethanol. The cofactor assignment in the model of van Gulik et al. (Biotechnol Bioeng 68(6):602–618, 2000) was supported using the published genome annotation of P. chrysogenum. Metabolic flux analysis showed that NADPH requirements in the cytosol remain nearly the same in these experiments due to constant biomass growth. Based on the cytosolic NADPH balance, it is known that the cytosolic aldehyde dehydrogenase in P. chrysogenum is NAD +  dependent. Metabolic modeling shows that changing the NAD + -aldehyde dehydrogenase to NADP + -aldehyde dehydrogenase can increase the penicillin yield on substrate

PHEF HEME Performance

The DWPF Salt Cell Vent Condenser (SCVC) includes a High Efficiency Mist Eliminator (HEME) designed to remove mercury aerosols that may form in the Precipitate Reactor (PR) condenser. The Savannah River Technology Center was requested by DWPF to make a performance assesssment of a prototypic HEME element in the vent system of the Precipitate Hydrolysis Experimental Facility at TNX.[sup a

Late wash cross-flow filter organic balance

A recent DOE-Savannah River review of the results and data from the Late Washing Crossflow Fitter assessment identified the fate of biphenyl as a concern in the Late Washing material balance. The concern arose because after the late washing operation only about 40% of the biphenyl remained in the irradiated precipitate and analyses of the spent wash water stream did not account for the missing biphenyl [2]. This document summarizes the results of subsequent filtration studies on the behavior and fate of all known organic precipitate feed components including biphenyl. The study employed a statistically designed material balance across a laboratory crossflow fitter. Data from two separate experiments are presented here. Results of the first study indicated no statistically significant loss of biphenyl, diphenylmercury, 0-terphenyl, diphenylamine, or aniline. Results did indicate minor losses of phenylboric acid, M-terphenyl, P-terphenyl, and a significant production of phenol, believed to be due to the way in which the experiment was performed. A second experiment demonstrated no statistically significant lose of any of the organic compounds

PHEF HEME performance

The DWPF Salt Cell Vent Condenser (SCVC) includes a High Efficiency Mist Eliminator (HEME) designed to remove mercury aerosols that may form in the Precipitate Reactor (PR) condenser. The Savannah River Technology Center was requested by DWPF to make a performance assesssment of a prototypic HEME element in the vent system of the Precipitate Hydrolysis Experimental Facility at TNX