DIAL's Research Highlights
Diagnostic Instrumentation & Analysis Laboratory
Support of Closure Sites
Fernald Silos Project Monitoring and Control Integration
Waste stabilization formulation development. Formulation testing continued. During June, the primary goal was to expand the formulation testing using ADVACAST 530, a viscosity modifier, in conjunction with blast furnace slag. It is expected that during the processing phase, the non-homogeneity of the K-65 material will create significant difficulties in handling both the waste slurry and the grout product. ADVACAST 530 is a super plasticizer intended to reduce the viscosity of the final grout mixture without increasing the amount of bleed water present. However, preliminary testing has proven that the use of ADVACAST 530 does in fact increase the amount of bleed water for a given formulation. The testing also demonstrated that the amount of ADVACAST 530 required to create a self-pouring, self-leveling mix was three to five times the doping level indicated by the manufacturer.
The use of blast furnace slag in conjunction with the ADVACAST 530 proved to reduce the presence of bleed water on the grout samples. Samples were prepared with 10% and 20% percent of the total sample weight) slag. The slag replaced an equal amount of fly ash from the formulation. The 20% slag samples had acceptable mix and flow properties in addition to a lack of free water at 120 hours.
Planned activities. The following activities are planned for the upcoming months:
Accelerating Phytoremediation by Monitoring Plant Status
During the month of June, we continued an experiment on mercury phytoremediation, the experiment was started in May, and is expected to finish in July. Meanwhile, we have been analyzing samples and data from previous experiments.
Bio-availability and Speciation of Mercury in the Oak Ridge Ecosystem
During this month, the two 8 ft x 4 ft x 4 ft acrylic aquarium tanks were made by the manufacturer and shipped. We started a preliminary mini-test bed experiment with river sediment from East Fork Poplar Creek of Oak Ridge, TN. Sediment was treated with HgCl2 at 100 mg/kg. At the same time, we are continuing to study the changes of bio availability of mercury species in contaminated soils with plantings. In addition, the first draft of the manuscript on "Mercury Bio availability and Speciation of Mercury in an Oak Ridge Soil of Tennessee, USA" has been prepared.
We plan to submit the mercury manuscript to the Environmental Pollution journal in the coming month. We will continue the preliminary experiments on a small size test bed with new functioned metal/soil blender/mixer.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
During May, our collaborators at Hanford were contacted to arrange a conference call to report our progress and to discuss our efforts for them for the next Cooperative Agreement Year. This month we have learned that this conference call is scheduled for Wednesday, July 27.
Stereovision. During June, the stereovision effort recorded images of reference objects in order to obtain estimates of our current volume determination uncertainty; these efforts are on-going.
Laser-induced fluorescence-spectral imaging. During June, the laser-induced fluorescence-spectral imaging effort investigated the effect of laser power on LIF signal intensity of uranyl acetate for both 532-nm and 355-nm excitation. All the uranium chemicals used to date have been "hand-me-downs" and hence of uncertain purity or even uncertain identity. Since LIF was observed for all uranyl compounds except uranyl formate, a radiological analysis of the uranyl formate was performed to verify the presence of uranium in the compound. Commercial sources for uranium compounds were found. After receiving permission from MSU's Radiological, Chemical, and Laboratory Safety Committee, orders have been placed for the purchase of small amounts of five simple uranium/uranyl compounds.
Microwave-induced plasma-cavity ringdown spectroscopy. The charge-coupled device (CCD) detector of the plasma system was sent back for service after intensive use. A manuscript entitled "Real-time Measurements of Elemental Mercury Naturally Evaporated from Contaminated Soil and Water Using Cavity Ringdown Spectroscopy" was written for publication in a refereed scientific journal.
Fiber optic sensors. This month the fiber optic sensors effort purchased a computer and a fast response data acquisition card for a data acquisition system to read the photomultiplier tube signal. The computer has been received. In addition, we sealed the liquid core waveguide fiber/silica fiber unit into the black rubber tube in order to shield the sensor from stray light.
Fourier transform profilometry. During June, the FTP effort continued our endeavors to reduce the measurement uncertainty of submerged objects. For submerged targets, FTP measurements with different camera-projector separations were performed; preliminary results indicate that measurements are affected by camera-projector distance and by the incidence angle of the light. Development of prototype software for motion control of the FTP probe has been completed for use of a single motor; further refinements including incorporation of all four motors is in progress. Modification of the probe tower motor to incorporate an encoder is nearing completion; the encoder will permit remote determination of probe extension length. Our efforts to contact TVA to learn about conditions and schedule for testing at the Regenesys facility continued, as did our efforts to reduce the weight of the elbow section housing the FTP optics.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
Development of training sets for the neural network application continued. Data were generated for the H2O, NaNO3, Al(OH)3, NaNO2, NaOH system as a function of input loadings and dilution. The data were parsed into the NOL software and used to develop the relationships between the various conditions and parameters. Correlation coefficients were generally greater than 0.99, indicating that the thermodynamic data can be successfully imported into a neural network. Additional data for testing the net were developed and are being evaluated against the base training functions. Some questions remain as to interfacing the network with the G2 model. These primarily concern data formats and the information desired by CH2M Hill engineers.
Data for the saturated S-109 pilot scale experiment conducted previously at FIU was obtained and is being evaluated. ESP calculations are expected to commence early next month. Additional solubility papers are being prepared for submission to the Journal of Chemical and Engineering Data.
Flexible Scintillating Optical Fiber Sensor for Determination of Liquid Level
The resolution of the existing PMT detector/program was tested during this reporting period with unsatisfactory results. Therefore, a computer with a faster responding data acquisition system was purchased to improve the capability of the system. Additionally, rubber housing for the liquid core waveguide was set-up to maximize the shielding of the detection system from stray light. Upon receipt of the data acquisition system, the PMT will be reprogrammed accordingly.
Disposition of Idaho HLW Calcine
Support of INEEL Calcine Disposition Project
TCLP analyses on the most recent iron phosphate compositions were completed and reported.
The chemical analyses for the hydroceramic waste forms have been completed. These analyses are to confirm calculations for waste loading and for PCT normalization. The test plan spreadsheet has been updated with the result of the analyses.
Hydroceramic waste forms have been made up using 25%, 30% and 35% waste loadings using the finer particulate feed materials. The 25% batch had a pudding consistency and was not that different from earlier compositions, but the other two needed to be spooned into the molds. It will be interesting to compare the results of these batches.
Confirmatory chemical analyses of the phase I fine particle batch and the phase II simulant have been completed.
Scoping tests have begun on the Phase II mixtures to get a sense of pourability and self-leveling properties. Increasing amounts of a 1:1:1 mixture (cement/fly ash/slag) were mixed with the calcine to determine the approximate proportions that would provide acceptable properties. Beginning with a 1:1 ratio of mixture: calcine through combinations of 2:1, 2.5:1, and 3:1, the material went from a watery consistency, to 30-weight oil, to milkshake, to just barely self-leveling.
The moisture content of RSH-1 was found to be 2.14% after drying for 24 hours at 400C.
In early June, a paper, "Solidification and Stabilization of High Level Calcinated Waste," based on our work at the Mississippi Water Environment Association was presented by Annu Marwaha. He won second prize in the competition.
Support of SRS Salt Disposition and Other SRS Alternatives
Support for SRS Salt Disposition Alternatives
Comparisons of literature values to ESP model values for the potassium-hydroxide-water and potassium-nitrate-water systems at a number of different temperatures have been completed. Results demonstrate good agreement with literature. Calculations for potassium nitrate in 1 and 3-m NaOH and potassium nitrate-sodium nitrate in water and 1 and 3-m NaOH at 25°C and 50°C were completed and compared to literature values when available. Results of these calculations and the systems identified for future solubility studies will be included in a letter report sent to the site. Cesium calculations and comparisons have begun and are slated for completion in July. Additional literature information collection is continuing for strontium, plutonium, and technetium.
FIU has completed the column experiment for the SRS 41 aged simulant test. We are awaiting analytical results from their report in order to compare the predictions of the model.
On-line Analysis for Defense Waste Processing Facility
To evaluate an experimental configuration that uses only small quantities of slurry for LIBS measurement, we placed the slurry sample in a small container (70-mm height, 20-mm dia.). A small hole at the bottom of container was connected to a peristaltic pump. The air flowing through the hole to the slurry container is used to mix the slurry. The laser beam was focused at the slurry sample via a 5-mm hole in the cap of the container. The RIC slurry samples which contain 12% Fe and 8% Al were used in this experiment. Since the physical and geometric parameters affect the reproducibility of the LIBS signal, we tried to keep all the experimental parameters during the experiments. The measurements were repeated several times in two weeks, The results from various slurry data were consistent. The RSTD from different days were all around 10%. The repeatability trend of LIBS data for intensity ratios is closer to linear than the absolute intensity data. The LIBS calibration data of Fe for slurry using this experimental configuration was obtained. The intensity ratio of Fe/Al for Fe concentration between 12 - 18% was found to increase linearly with the concentration of iron in the slurry. More data of this type will be collected.
Support of Production of High Waste Loading Glasses in the DWPF
More video observations have been done for the 155% and 185% batches to study cold cap formation as well as melt behavior. A new set of experiments to observe the interaction of the various frits with the SRAT simulant has been set up and will be done over the next reporting period.
HEPA Filter Performance Assurance
Regenerable HEPA Filter Performance Testing
During the month of June, a test plan was drafted to evaluate the performance of Mott regenerable filter media under repeated load/wash cycles. A new optical particle measuring unit (LPC-0710) was received from Particle Measuring Systems. The unit was sent back because of a faulty display. A new unit was received and sent back after communication between the unit and the PC could not be established. The unit is now back at DIAL and will be tested. A manuscript titled "HEPA Filter Performance Under Adverse Conditions" was submitted and will be presented at the International Nonwovens Technical Conference, September 19 - 22, 2005, St. Louis, MO.
Inquiries may be addressed to:Dr. John Plodinec, Director
205 Research Blvd.
Starkville, MS 39762-5932