Initial results from the canistered waste forms produced during the first campaign of the DWPF Startup Test Program

As part of the Defense Waste Processing Facility (DWPF) Startup Test Program, approximately 90 canisters will be filled with glass containing simulated radioactive waste during five separate campaigns. The first campaign is a facility acceptance test to demonstrate the operability of the facility and to collect initial data on the glass and the canistered waste forms. During the next four campaigns (the waste qualification campaigns) data will be obtained which will be used to demonstrate that the DWPF product meets DOE`s Waste Acceptance Product Specifications (WAPS). Currently 12 of the 16 canisters have been filled with glass during the first campaign (FA-13). This paper describes the tests that have been carried out on these 12 glass-filled canisters and presents the data with reference to the acceptance criteria of the WAPS. These tests include measurement of canister dimensions prior to and after glass filling. dew point, composition, and pressure of the gas within the free volume of the canister, fill height, free volume, weight, leak rates of welds and temporary seals, and weld parameters

The physical properties and chemical composition of the gas within the free volume of canistered waste forms

The DWPF must meet Waste Acceptance Preliminary Specifications (WAPS) for acceptance of the DWPF canistered waste forms. A number of these specifications deal with the exclusion of non-wasteglass (or foreign) materials within the canistered waste forms. Those material which are specifically excluded include the following: Free Liquids, Free Gases, other than cover or radiogenic gases, Explosives, Pyrophorics and Combustibles, and Organics. This report documents the results obtained by carrying out an assigned task as described in three task plans. The task plans cover the determination of pressure, gas composition and relative humidity of SRL canistered waste forms; and organic and inorganic analysis of volatilized and condensed species within SRL canistered waste forms. These results provide evidence to demonstrate compliance with these specifications and will be included in the Waste Form Qualification Report (WQR). In all, four canistered waste forms, produced during the Scale Glass Melter (SGM) campaigns, were examined. The internal gas pressure, dewpoint temperature and gas composition were determined for each canistered waste form. The experience gained in these experiments will be used to generate procedures for obtaining the same information on canistered waste forms produced during the Integrated Cold Runs (ICR). 10 refs., 2 figs., 1 tab

HOOK-GRIP IMPROVES POWER CLEAN KINETICS AND KINEMATICS

The purpose of this study was to compare one repetition maximum (1RM), as well as biomechanical outputs across a range of loads (75-100%) in the power clean (PC) utilizing the hook grip (HG) or closed-grip (CG). Eleven well-trained males (PC 1RM=1.34xBW) with at least six months of HG experience volunteered. Following a familiarization session, PC 1RM testing with the HG and CG were completed in random order, 5-7 days apart on a force platform with linear position transducers and 2D motion capture. The HG condition resulted in greater PC 1RM (6.6%, ES=0.43), peak barbell velocity (2.9-5.2%, ES=0.41-0.70) and relative peak barbell power (5.7-15.1%, ES=0.32-0.71) at all submaximal loads compared to CG. No substantial differences were found in horizontal bar-path (ES=-0.27-0.32). The results of this study suggest that athletes who implement weightlifting movements in their physical preparation should adopt the HG

The effect of gamma irradiation of the volatility and redox state of simulated DWPF high-level nuclear waste glasses

Gamma-induced volatility of simulated DWPF high-level nuclear waste glasses is highly dependent upon the redox state of the glass. For oxidized glasses with an Fe[sup 2+]/(Fe[sup 2+] + Fe[sup 3+]) ratio < 0.1, no volatility was detected after gamma irradiation. Since the projected DWPF high-level radioactive waste glasses will be oxidized, no significant gamma-induced volatility is expected for these glasses upto the glass transition temperature. For larger pieces of highly-reduced DWPF simulated waste glass, no volatility was observed (using [approximately]100 mg pieces in the TGA) after gamma irradiation. However, for powdered samples of this reduced glass, volatility changes upon gamma radiation were detected at 350 and 475[degree]C. The volatility at 350[degree]C was due to changes at the glass surface whereas the change in volatility at 475[degree]C were due to interactions of gamma irradiation within the bulk of the glass. The glass transition temperatures of both oxidized and reduced glasses were unaffected by gamma irradiation but did increase upon a second heat cycle. Results are also presented which reveal that no significant change in redox level within the glass occurred as a result of gamma irradiation

Molecular Electroporation and the Transduction of Oligoarginines

Certain short polycations, such as TAT and polyarginine, rapidly pass through the plasma membranes of mammalian cells by an unknown mechanism called transduction as well as by endocytosis and macropinocytosis. These cell-penetrating peptides (CPPs) promise to be medically useful when fused to biologically active peptides. I offer a simple model in which one or more CPPs and the phosphatidylserines of the inner leaflet form a kind of capacitor with a voltage in excess of 180 mV, high enough to create a molecular electropore. The model is consistent with an empirical upper limit on the cargo peptide of 40--60 amino acids and with experimental data on how the transduction of a polyarginine-fluorophore into mouse C2C12 myoblasts depends on the number of arginines in the CPP and on the CPP concentration. The model makes three testable predictions.Comment: 15 pages, 5 figure

Homogentisate 1-2-Dioxygenase Downregulation in the Chronic Persistence of Pseudomonas aeruginosa Australian Epidemic Strain-1 in the CF Lung

Some Pseudomonas aeruginosa strains including Australian Epidemic Strain-1 (AES-1 or AUS-01) cause persistent chronic infection in cystic fibrosis (CF) patients, with greater morbidity and mortality. Factors conferring persistence are largely unknown. Previously we analysed the transcriptomes of AES-1 grown in Luria broth, nematode growth medium for Caenorhabditis elegans assay (both aerobic) and artificial sputum medium (mainly hyp- oxic). Transcriptional comparisons included chronic AES-1 strains against PAO1 and acute AES-1 (AES-1R) against its chronic isogen (AES-1M), isolated 10.5 years apart from a CF patient and not eradicated in the meantime. Prominent amongst genes downregulated in AES-1M in all comparisons was homogentisate-1-2-dioxygenase (hmgA); an oxygen-dependent gene known to be mutationally deactivated in many chronic infection strains of P. aeruginosa. To investigate if hmgA downregulation and deactivation gave similar viru- lence persistence profiles, a hmgA mutant made in UCBPP-PA14 utilising RedS-recombinase and AES-1M were assessed in the C. elegans virulence assay, and the C57BL/6 mouse for pulmonary colonisation and TNF-α response. In C. elegans, hmgA deactivation resulted in significantly increased PA14 virulence while hmgA downregulation reduced AES-1M virulence. AES-1M was significantly more persistent in mouse lung and showed a significant increase in TNF-α (p<0.0001), sustained even with no detectable bacteria. PA14ΔhmgA did not show increased TNF-α. This study suggests that hmgA may have a role in P. aeruginosa persistence in chronic infection and the results provide a starting point for clarifying the role of hmgA in chronic AES-1

Dew point, internal gas pressure, and chemical composition of the gas within the free volume of DWPF canistered waste forms

The Defense Waste Processing Facility (DWPF) produced 55 canistered waste forms containing simulated waste glass during the four Waste Qualification campaigns of the DWPF Startup Test Program. Testing of the gas within the free volume of these canisters for dew point, internal gas pressure, and chemical composition was performed as part of a continuing effort to demonstrate compliance with the Waste Acceptance Product Specifications. Results are presented for six glass-filled canisters. The dew points within the canisters met the acceptance criterion of < 20{degrees}C for all six canisters. Factors influencing the magnitude of the dew point are presented. The chemical composition of the free volume gas was indistinguishable from air for all six canisters. Hence, no foreign materials were present in the gas phase of these canisters. The internal gas pressures within the sealed canisters were < 1 atm at 25{degrees}C for all six canisters which readily met the acceptance criterion of an internal gas pressure of less than 1.5 atm at 25{degrees}C. These results provided the evidence required to demonstrate compliance with the Waste Acceptance Product Specifications

Glass Waste Forms for Oak Ridge Tank Wastes: Fiscal Year 1997 Report for Task Plan SR-16WT-31, Task A

Through the Tanks Focus Area, the Office of Science and Technology has funded the Savannah River Technology Center (SRTC) and the Oak Ridge National Laboratory (ORNL) to develop formulations which can incorporate sludges from Oak Ridge (OR) Tank Farms into an immobilized waste form. SRTC has been developing a glass waste form, while ORNL has been developing a grout waste form for the tank farms sludges. The four tank farms included in this task are: Melton Valley Storage Tanks (MVST), Bethel Valley Evaporator Service Tanks (BVEST), Gunite and Associated Tanks (GAAT)and Old Hydrofracture Tanks (OHF). The first element of the SRTC task for FY97 was to develop a glass formulation to immobilize a blended sludge from the MVST and the BVEST. ORNL had previously developed a soda-lime-silicate (SLS) glass for the MVST sludge. SRTC has reproduced this work and expanded on it for the blended MVST/BVEST sludge. SRTC also performed a durability test on the resultant glasses. The normalized sodium and silicon leachate concentrations for the soda lime silica glasses readily met the Environmental Assessment glass (a borosilicate glass) benchmark limits for these two elements. Additional efforts at the SRTC included the verification of the glass formulation prior to the ORNL radioactive demonstration and technical consultations during the radioactive demonstration. However, the major emphasis for SRTC in FY97 was on the second element of this task, the overall blended average of the tank farms. The second element focused on developing a glass formulation which would immobilize a sludge with a composition obtained from averaging the contents of all four tank farms (composite composition). Although blending the contents of all four tank farms is not feasible, this average composition provides a basis from which to develop a glass formulation. Once a frit formulation was developed which produced a durable glass waste form at relatively high waste loadings, then a statistically designed approach was implemented to determine the size of the sludge compositional window which could be adequately immobilized by the frit formulation. This report summarizes the SRTC results of Task A of Task Plan SR-16WT-31 for FY97

SALTSTONE VARIABILITY STUDY - MEASUREMENT OF POROSITY

One of the goals of the Saltstone Variability Study is to identify the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. One of the key performance properties is porosity which is a measure of the volume percent of a cured grout that is occupied by salt solution (for the saturated case). This report presents (1) the results of efforts to develop a method for the measurement of porosity of grout samples and (2) initial results of porosity values for samples that have been previously produced as part of the Saltstone Variability Study. A cost effective measurement method for porosity was developed that provides reproducible results, is relatively fast (30 to 60 minutes per sample) and uses a Mettler Toledo HR83 Moisture Analyzer that is already operational and routinely calibrated at Aiken County Technology Laboratory. The method involves the heating of the sample at 105 C until no further mass loss is observed. This mass loss value, which is due to water evaporation, is then used to calculate the volume percent porosity of the mix. The results of mass loss for mixes at 105 C were equivalent to the results obtained using thermal gravimetric analysis. The method was validated by comparing measurements of mass loss at 105 C for cured portland cement in water mixes to values presented in the literature for this system. A stereopycnometer from Quantachrome Instruments was selected to measure the cured grout bulk densities. Density is a property that is required to calculate the porosities. A stereopycnometer was already operational at Aiken County Technology Laboratory, has been calibrated using a solid stainless steel sphere of known volume, is cost effective and fast ({approx}15 minutes per sample). Cured grout densities are important in their own right because they can be used to project the volume of waste form produced from a given amount of salt feed of known composition. For mixes made from either Modular Caustic Side Solvent Extraction Unit (MCU) or Salt Waste Processing Facility (SWPF) simulants in premix, the porosities averaged near 62 % with an uptake of water through hydration reactions equivalent to a water to cementitious materials ratio (w/cm) of 0.04. For a mix made from a Deliquification, Dissolution and Adjustment (DDA) simulant and premix, the porosity is slightly lower at 57 % with an uptake of water through hydration reactions equivalent to a w/cm ratio of 0.07. Data are presented which demonstrate that porosity is inversely related to the heat of hydration, a measure of the extent of the hydration reactions. Modeling of porosities from three of the statistically designed phases of the Saltstone Variability Study demonstrated that the data could be fit to a linear model with an R2 of 0.74 and no statistical evidence for a lack of fit. The model revealed that w/cm ratio plays a significant role in the total porosity with porosity increasing as the w/cm ratio increases. Other elements of the model include positive correlations with the free hydroxide ion concentration and the total nitrate plus nitrite ion concentration. For a series of mixes in which the composition of the salt solution remained constant (MCU baseline) the porosity increased from {approx}60 to 65 % as the w/cm ratio increased from 0.55 to 0.65