Monthly Research Progress
Institute for Clean Energy Technology
Support of Oak Ridge Site Closure
Characterization of Corrosion for Closure of Oak Ridge Research Reactor
A paper entitled "Quantitative Imaging Characterization of Aluminum Pit Corrosion in Oak Ridge Research Reactor Pool" was presented at the Advanced Environmental, Chemical, and Biological Sensing Technologies IV Conference (which was part of the umbrella Optics East 2006 Conference) in Boston, MA. This paper describes our development efforts and our December 2005 deployment into the Oak Ridge Research Reactor pool. Because of lack of funds for the end of the federal fiscal year, our Oak Ridge collaborators were unable to provide the required support to enable deployment into the Oak Ridge Research Reactor (ORRR) pool during September; a revised deployment date is being sought.
Bio-availability and Speciation of Mercury in the Oak Ridge Ecosystem
In October, we continued our study on bioavailability of mercury sulfide in soils. Indian mustard was used as a bioavailable indicator for HgS in contaminated soils. We tested the two varieties of Indian mustard and one species of brake fern.
In addition, a conference call was made with scientists from Savannah River National Laboratory. A joint proposal on bioavailabilities of both heavy metals and radionuclides and organic solvents at the US Department of Energy's Savannah River site is in preparation.
In November, we will move our analytical laboratory to a new room. A series of laboratory studies on bioavailability of Hg-contaminated soil will be conducted.
Accelerating Phytoremediation by Monitoring Plant Status
During this month, we continued the mercury phytoremediation experiments with Indian mustard and Chinese brake fern; the experiment was started in August. The Indian mustard experiment was finished in October, and the brake fern experiment is expected to finish in November or December. Also during this month, we have been conducting experiments to investigate the different mercury uptake mechanisms, such as plant root uptake of soil mercury and leaf intake of atmosphere Hg, using the special chambers designed and constructed by ICET engineers and technicians.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
Stereovision. During October, the stereovision effort performed more experiments with the FTP target board in the classroom at distances of 5, 10 and 20 feet and in the ICET hallway at a distance of 60 feet. We are continuing our efforts to search for optimum experimental parameters as well as stereomatching parameters (such as window size, matching range, etc.) for application to Hanford waste tanks.
Laser-induced fluorescence-spectral imaging. The laser-induced fluorescence-spectral imaging effort continued optimizing the 266-nm (fourth harmonic) output from our Nd:YAG laser continued this month. LIF experiments using 266-nm excitation and simple uranium compounds will be performed during November.
Microwave-induced plasma-cavity ringdown spectroscopy. During October, data processing of the previously recorded ringdown measurements of mercury vapors was completed. New efforts will focus on plasma-CRDS measurements of uranium using a blue diode laser.
Fiber optic sensors. This month the fiber optic sensors effort conducted an experiment using our packed optical fiber-compatible spectrometer to record spectra of scintillating light from our scintillating optical fibers. However, we found that our optical fiber-compatible spectrometer is not sensitive enough to detect very weak light signals (ca. 10,000 photons/second), although the engineers of the spectrometer manufacturer had indicated that this spectrometer should be capable of detecting light signals at that intensity level. Consequently, we designed another experiment in order to record the scintillating light spectra with our optical fiber-compatible spectrometer. In this experiment, scintillating light signal from a large-size scintillator (a quantum dot solution in a quartz cell or a large piece sol-gel silica scintillating cylinder) will be focused with a lens into an optical fiber, and detected with the optical fiber-compatible spectrometer. It is expected that the scintillating light intensity fed into the spectrometer will be much higher than that in our previous experiment using fiber scintillators. The system for this experimental design has been built. We had planned to test this new design at the end of October. However, due to a fire near the university's Cs-137 gamma irradiator that we use in these measurements, the test has been postponed, but is expected to be conducted in early November.
Fourier transform profilometry. During October, the Fourier transform profilometry (FTP) effort learned that our Hanford collaborators decided not to accelerate by six months demonstration of the FTP probe system at Hanford's Cold Test Facility. Our efforts to prepare a report describing the results from the first stage of simulation testing continued; a draft of the report will be provided to Hanford in November. Fabrication of a curved tank bottom has begun; completion is expected in November. The curved tank bottom simulator will enable us to evaluate the performance of the FTP system under conditions simulating those that will pertain within the Hanford waste tanks. We have been utilizing MSU's Cs-137 gamma irradiator in order to test the ability of critical FTP optical components (Ronchi filter, diffuser, SONY 78B camera) to withstand gamma radiation. Since none of these components had exhibited significant degradation at the (nominal) 21.6-R/hour exposure rate although they had been exposed to a cumulative dose of tens of thousands of R, it was decided to terminate that experiment and to repeat the experiment using new components at a significantly higher dose rate (about 216 R/hour). After the new experiment had progressed for about 40 hours, a fire near MSU's gamma irradiator shutoff the electric power, terminating data recording. The experiment is expected to be continued in early November. Our development of a waste tank floor mapping algorithm and of the associated tank imaging stitching algorithm are almost complete. A test platform has been installed in ICET's high bay; this will enable us to simulate tank deployment using our three-foot prototype robotic probe deployment system.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
ESP model simulations were completed for the FIU S-109 unsaturated salt cake dissolution experiment. The results were compiled and presented during a bi-weekly conference call. The simulation was involved with over 75 dissolution steps that consisted of three unit operations each, diluent (water) addition, separation, and partitioning of the aqueous phase between the brine remaining in the column and that collected after passing through the column. Excellent agreement was observed between the experimentally determined height of the salt bed within the column and that calculated from the model assuming a porosity of 30%. Aqueous phase densities and nitrate and sodium concentrations were in semi-quantitative agreement with the experimental results.
Differences between the model predictions and the actual data can be ascribed to channeling. This study is being combined with previous large-scale pilot simulation salt cake dissolutions studies performed previously into a topical report.
Solubility experiments on the Na-F-PO4-OH system at 15°C have been completed. This data will be compared to the previously obtained data at 20°C and the earlier studies at 25, 35 and 50°C. Plans are to append the V7DBLSLTDB database with the new data.
Work on post-processing the results expected from the neural network has started. At present the training set for the network consists of total inputs (solid and aqueous phase) as a molecular basis and outputs consisting of desired physical parameters such as density, pH, and phase information, along with aqueous phase ionic concentrations. With the total input known and the output consisting of only the aqueous phase it is possible to determine the solid phase speciation. Logic for a program to perform these tasks has been developed and programming started.
Disposition of Idaho HLW Calcine
Support of CH2M-WG Calcine Disposition Project
The test stand for the mock-up system has been built. The next step will be to install the equipment (feeders, mixers, etc.). We expect to begin shakedown testing of the mock-up over the next month.
A paper entitled "Grout Waste Form for the Disposition of Idaho HLW Calcine" was presented at the October meeting of the American Ceramic Society.
Support of SRS Salt Disposition and Other SRS Alternatives
Modeling and Experimental Support for High-level SRS Waste Disposition
Solutions containing solids for the experimental systems, KNO3-NaNO3-Water, 1- and 3-m NaOH and CsNO3-NaNO3-Water, 1- and 3-m NaOH at 50°C, have begun preparation for analysis. Additional nitrate solids will continue to be added to those solutions without the appearance of solids.
Compilation and model comparison of FIU SRS 41H simulant testing will be included in a final report prepared for the Hanford and SRS site personnel.
Process Improvements for the Defense Waste Processing Facility (DWPF)
On-line slurry analysis. Work continued on evaluating LIBS for the analysis of Pu residue generated during the processing of the weapons grade Pu. LIBS measurements are being performed using cerium oxide as a surrogate for plutonium oxide in a surrogate powder sample. Sampling methods including making pellets from the powder sample (with and without binder) or adhering one layer of the powder sample on a substrate are being evaluated to identify the best sampling method. LIBS calibration data for Ce, Cr, Mo, W, Si, Ta, Fe, Ni, Zn, Al, Gd, Mg in pellet and powder forms were collected using five powder samples of different compositions. The accuracy and precision of the LIBS analysis from the samples in pellet form and in powder form are better than 5% for the major elements and better than 10% for most of the minor elements. This preliminary study already shows the LIBS's capability for direct monitoring of the Pu residue composition with reasonable accuracy in either pellet form or in a thin layer of powder on double-sided tape. Dr. Kristine Zeigler, SRNL, visited ICET Oct. 23 - 25 to discuss the progress of the current project and also to discuss the future testing plans at SRNL.
Improvement of waste throughput. Experiments run so far to examine the relative reaction rates of the two frits have not provided the information expected. These tests have been done both with a dried version of the Case 7d SRAT as well as with the slurry. It appears that in both sets of experiments, Frit 200 reacts more rapidly (at lower temperatures) than Frit 320, and that is not what has been observed in practice. Evaluation by differential scanning calorimetry and optical microscopy has not revealed any reasons for the melting observations.
A paper entitled "Melt Rate Enhancement and Improved Waste Loading for DWPF Glasses" was presented at the October meeting of the American Ceramic Society.
A shipment of SB4 simulant Frit 503, and Frit 418 was received this month. We have done chemical and thermal characterization of these materials. Several experiments have also been run to compare melting rates. DSC analysis of these two frits have been done and compared as well. As with the comparison of Frits 200 and 320, the results are inconclusive.
Discussions have been started on a task involving using ICET diagnostic instrumentation to assist with melting studies using the Cold Cap Evaluation Furnace (CEF) which has been built at SRNL. This task will be a large part of our effort in the coming year.
Support of the Fernald Silos Project
Fernald Silos Project - Remediation Process Support
Final decontamination and disposition of the Fernald building and the associated systems is ongoing. Communication with the Fernald Management Team will continue through project completion.
HEPA Filter Performance Assurance
Regenerable HEPA Filter Performance Testing
Media velocity testing of Camfil Farr and Flanders nuclear grade AG-1 HEPA filters was continued. Testing was completed with the 3-micron D50 cut-point in place and without the cyclone in place using 30% KCl. Tests were completed for Camfil Farr filters at 357 and 285 scfm with the cyclone in place. Camfil Filters were evaluated with the cyclone removed at 285, 342 and 228 scfm. Flanders filters were tested with the cyclone removed at 200, 250, 300, 375 and 438 scfm and at 200 scfm with the cyclone in place. Data analysis of all filter trials was initiated.
Inquiries may be addressed to:Dr. Roger King, Interim Director
205 Research Blvd.
Starkville, MS 39762-5932