Monthly Research Progress
Institute for Clean Energy Technology
Support of Oak Ridge Site Closure
Characterization of Corrosion for Closure of Oak Ridge Research Reactor
Because of lack of funds for the end of the 2006 federal fiscal year, our Oak Ridge collaborators were unable to provide the support required to enable deployment into the Oak Ridge Research Reactor (ORRR) pool during September.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
Stereovision. Progress on the stereovision effort was significantly slowed during March by the unexpected departure in December of the graduate student working on this effort. During March, several graduate students interested in working on this effort were interviewed. It is expected that one will be selected in April and progress on this effort will resume.
Fourier transform profilometry. During March, the Fourier transform profilometry (FTP) effort concentrated on preparation for the FTP Stage II performance evaluation. This series of experiments is designed to determine the ability of FTP to accurately stitch together volume determinations from overlapping images.
First, the FTP simulator computer program was used to generate synthetic images that were subsequently analyzed by the FTP analysis software tools. The purpose was to verify that the stitching procedure behaves as anticipated and thus to validate the FTP stitching software. Initially we were puzzled as to why stitching along one of four image boundary scenarios had yielded what appeared to be significantly higher error (-6.7% vs. -2.9% for the other cases) when the error was reported as relative error. Upon closer examination of the input conditions, it was noted that the test target was very small when compared to waste objects that are currently being encountered by Hanford post-retrieval. The test targets consisted of two right circular cones situated along the image boundary with each cone having a base of 10.0 cm and a height of 4.0 cm (true volume of 104.7 cm3). The camera-to-surface distance utilized was 6.1 meter (20 ft). When reported as an absolute error, the error is only 7 cm3. Considering the analyzed image size and the anticipated average waste deposit height, ~2.5 cm, this compares very favorably to the expected average tank volume contribution for that image, ~1350 cm3 (< 0.52%).
Secondly, preliminary preparations were made to setup the current full-scale FTP optical configuration on an optical table whereby the camera and grid projector can be independently manipulated in the "pan" and "tilt" directions. Previous "stitching" had made obvious the need for significant improvement (two orders of magnitude) in the determination of pan and tilt angles. To meet this angle-resolution requirement, a "sine bar"-type apparatus was designed and constructed that is expected to meet the required angle measurement resolution of 0.02°.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
Discussions are in progress with OLI Systems, Inc. regarding the porting of the V7DBLSLTDB database into the mixed solvent electrolyte (MSE) model. Specific binary and ternary systems have been identified and then prioritized based on the projected importance to both Hanford and Savannah River. A main goal is to have OLI incorporate the database into their Public database thereby relieving us of re-fitting the entire compilation whenever OLI releases a new version of the Environmental Simulation Program (ESP).
Additional experiments were conducted on the gibbsite-to-boehmite transition. Prepared samples were subjected to thermogravimetric analysis and some were also sent for x-ray diffraction. Of the samples prepared from pure aluminum wire and sodium hydroxide some 70% of the original solid was found to be boehmite. Attempts are in progress to find reliable sources of gibbsite that are commercially available.
Additional discussions with Hanford site engineers were undertaken with regard to development of the neural network. Work on automating ESP is in progress and most all spreadsheet operations have been completed including reconciling the charge balance and generation of the molecular stream from data available in the Best Basis Inventory. We intend to begin calculations with wastes contained in one tank farm for proof of concept. Following these efforts the data will be formatted for input into the neural network and checks on the network performance will be developed.
Disposition of Idaho HLW Calcine
Support of CH2M-WG Calcine Disposition Project
A safety review of the assembled feeders, mixers, and control equipment has been completed. The first shakedown test was run by mixing the powders and then adding the water. This was not particularly successful as the solids mostly stayed in the bottom of the mixer. The next test will be run differently, perhaps by having the water already in the mixer as the powders are added.
Support of SRS Salt Disposition and Other SRS Alternatives
Modeling and Experimental Support for High-level SRS Waste Disposition
The KNO3/NaNO3 and CsNO3/NaNO3 systems in water, 1-m and 3-m NaOH solutions at 50°C have been prepared for a second series due to inconsistencies and non-formation of solids during the first series preparation and subsequent analyses. Calculations using version 7.0 ESP and the V7dblslt database for modeling comparisons of the FIU SRS 41 aged simulant tall column experiment are currently underway for inclusion in a final topical report. Also, communications with the site have indicated that sampling of tank 25 has been completed and a simulant composition is being developed.
Process Improvements for the Defense Waste Processing Facility (DWPF): On-line Analysis
Work is still concentrated on the subtask of analyzing the plutonium oxide residues. We are testing different fiber optic configurations for delivering the laser pulse to create laser induced spark plasma on the sample surface. Beside the usual fused silica optical fiber, we are also evaluating a one-meter hollow-core silica waveguide from Polymicro Technologies, LLCA for transmitting high pulse energy laser. We have successfully coupled a 40-mJ, 532-nm laser beam through this fiber with 50% efficiency. To improve the coupling efficiency, we are requesting another hollow fiber from Polymicro Technologies, LLCA which should give low loss for visible light. A one channel LIBS spectrometer from Ocean Optics was ordered and received. Work to test this new spectrometer with a BigSky laser is in progress.
Process Improvements for the Defense Waste Processing Facility (DWPF): Improvement of Waste Throughput
X-ray diffraction (XRD) experiments on SB4 simulant with Frits 418 and 503 were begun this quarter. Materials heated to 600°C, 700°C and 800°C are being examined. It is clear that there are new phases appearing as other phases disappear with increased temperature. The most interesting appearing/disappearing phases are two major phases of silica, cristobalite and tridymite. There may also be lithium silicate and lithium disilicate. The changes of these phases in these melts could provide insight to the over all melting behavior.
In order to confirm the presence of the lithium silicate and disilicate, we will make up some glass compositions, crystallize them, and check their XRD patterns and characterize thermal behavior by differential scanning calorimetry (DSC).
Process Improvements for the Defense Waste Processing Facility (DWPF): Melter Monitoring
Nothing to report.
DOE Headquarters Support
DOE HQ Road Map
ICET participated in the Road Map development activities by EM-20 during the latter part of the 2006 calendar year. ICETs Interim Director and Deputy Director attended two general meetings at DOE Headquarters in which road mapping was discussed. Additionally, the Deputy Director took part in the Road Mapping Workshop held at Headquarters during November.
Workshop on Heavy Metal Phytoremediation
ICET will host a workshop on the application of remote sensing to environmental monitoring. The workshop will be held in Starkville, Mississippi during the second or third quarter of 2007. Workshop planning will be a coordinated effort between personnel representing EM-20 at DOE Headquarters, Savannah River National Lab, and ICET. The workshop will focus on developing a two year research plan for developing and evaluating tools enabling use of remote sensing as a monitoring tool. Targeted monitoring parameters will include: contaminant plume migration, status of vegetation used in bioremediation, and ecological recovery from releases.
HEPA and Regenerable Filter Performance Assurance
Initial testing of the large CeraMem regenerable filters began. Experiments were conducted to determine the initial filtering efficiency, initial pressure drop, and approximate mass loading rate. These data were needed in order to devise a test plan for actual testing to be conducted during April. Additionally, the air back-pulse regeneration system was constructed and implemented.
Bio-availability Studies of Mercury and Other Heavy Metal Contaminants in Ecosystems of Selected DOE Sites
This month, we studied the kinetics of mercury release from Oak Ridge soil contaminated with HgS triggered by naturally occurred iron oxides. The release rate could be as high as around 10 ppb. Both the effects of time and concentrations of iron oxides have been examined.
The experiment is expected to be continued in the coming two months. More variables of the reactions and pathways such as release/exchange of sulfur, iron and pH will be carefully examined.
Phytoremediation and Long-term Monitoring of Selected Heavy Metal and Radionuclide Contaminants
During this month, we carried on a phytoremediation experiment using our homemade chamber. The experiment was started in February. Chinese brake fern was grown on clean soil, but the plant shoot was enclosed in a chamber containing mercury contaminated soil (from different sources such as Hg(NO3)2 and HgS). Our objective is to investigate the possible leaf uptake of mercury vapor from the atmosphere above contaminated soil. The experiment is expected to end in early April. Also during this month, two of our papers were published:
Development of New Technologies for DOE Site Applications
The ringdown measurements using 409-nm diode laser-plasma cavity ringdown spectroscopy have been conducted. Efforts are focusing on the improvement of electronic configuration of the system to improve the signal-to-noise ratio. Two different triggering modes, the single channel self-triggering mode and the one using a frequency combiner, are explored. Two papers on plasma-cavity ringdown have been accepted by the Sixteenth IEEE International Conference on Plasma Science.
Additionally, carbon isotopes with different abundance ratios of carbon dioxide mixed with argon and air in various concentrations are measured using the portable ringdown gas cell controlled by commercial electronics.
Development of Fiber Optic Sensor Technologies for DOE Site Applications
The work of the fiber optic sensor group was focused on developing the LCW fiber optic sensor for detecting mercury in air. We optimized the operation conditions for using a chemical reagent to react with mercury ions in water. The reaction product was monitored with LCW fiber optic spectrometric method. We also did a preliminary calibration experiment for using the developed method to detect trace mercury ions in water. A detection limit of 50-ng Hg2+/L can be achieved with a 1.5 meter LCW.
In order to develop a field readable instrument for detecting elementary mercury in air, our next step is developing a procedure to convert elementary mercury in air to solution. An amalgamating trapping/acid desorption procedure will be developed next.
Inquiries may be addressed to:Dr. Roger King, Interim Director
205 Research Blvd.
Starkville, MS 39762-5932