Monthly Research Progress
Institute for Clean Energy Technology
Support of Oak Ridge Site Closure
Characterization of Corrosion for Closure of Oak Ridge Research Reactor
Construction and development of a new submergible probe system continues. A conference paper describing our development efforts and the initial deployment into the Oak Ridge Research Reactor pool in December 2005 was prepared and submitted for publication. 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 September, we presented "Biogeochemistry of Mercury in Contaminated Oak Ridge Soils and Possible Phytoremediation Strategy" at SETC Asia/Pacific 2006 in Beijing, China. The presentation was well received by international community and potential collaboration was discussed. At the same time, we continued the study on bioavailability of mercury sulfide in Oak Ridge soil under controlled conditions.
In October, we will start a series of laboratory studies on effects of various natural and synthetic organic components/root exudates on solubility/bioavailability of mercury sulfide in Oak Ridge soil/sediments.
Accelerating Phytoremediation by Monitoring Plant Status
During the month of September, we have been conducting a mercury phytoremediation experiment with Indian mustard and Chinese brake fern; the experiment was started in August and is expected to finish in October. Also during this month, we have started an experiment 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. Special thanks to Mr. Walter Okhuysen and everybody from the ICET shop.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
Stereovision. During the month of September, the stereovision effort performed more experiments with the FTP target board in the classroom. We are continuing our efforts to search for optimum experimental parameters as well as stereo matching 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 has previously installed the optics to separate the 266-nm fourth harmonic of the Nd:YAG laser from the Nd:YAG fundamental and other harmonics. We have optimized the 266-nm output of the Nd:YAG laser and obtained acceptable laser power at 266 nm. LIF experiments using 266-nm excitation and simple uranium compounds will be performed during October.
Microwave-induced plasma-cavity ringdown spectroscopy. This month, the cavity ringdown spectroscopy effort continued analyzing the CRDS mercury vapor data collected last month from three types of mercury-spiked aqueous solution and soil. In the meantime, we are constructing an instrument case for a site-deployable ringdown system.
Fiber optic sensors. During September, the fiber optic sensors effort fabricated and tested a package for use with our optical fiber-compatible UV/Vis spectrometer. The package is designed to shield stray light from entering the spectrometer when it is used to record the spectrum of the scintillating emission signal from a scintillating optical fiber. This work is important because in our previous work, we detected the total scintillating optical signal, but we do not know the wavelength of the photons generated by the scintillating optical fiber. Several scintillating optical fibers have been made to date. We will use the spectrometer with this package to record the emission spectrum of the scintillating fibers.
Fourier transform profilometry. During September, the Fourier transform profilometry (FTP) effort responded to a request from our Hanford collaborators to investigate what would need to be done in order to accelerate by seven months the demonstration of the FTP system at Hanford's Cold Test Facility. An accelerated demonstration would assist Hanford by more quickly providing an alternative means of determining when Hanford waste tanks are sufficiently empty that personnel and equipment can be moved from one tank to the next tank to be emptied. We provided Hanford with the information and they are currently deciding whether or not to accelerate. In support of the potential acceleration, an engineering design review by MSU and other ICET engineers of the proposed FTP deployment system was successfully conducted. Utilizing the recommendations of the design review, development of the FTP manipulator and manipulator control is proceeding. 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 October. In order to test the ability of critical FTP optical components (Ronchi filter, diffuser, SONY 78B camera) to withstand gamma radiation, we have continued our radiation testing using MSU's Cs-137 gamma irradiator. Ten pocket chamber dosimeters provided by MSU's Radiation Safety Officer were used to characterize the intensity and distribution of gamma-ray radiation within the Cs-137 gamma irradiator. Our development of a waste tank floor mapping algorithm are on-going.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
Equilibration of the trisodium phosphate solutions at 15°C was achieved and filtration was begun. The lower temperature of these experiments has presented some difficulties. Although equilibration at the lower temperature is straightforward in the laboratory incubator it has been observed that separation of the Na3PO4·12H2O·0.25NaOH crystals is temperature dependent and changing the temperature changes the associated equilibrium. Thus, gravity filtration is now being performed within the confines of the incubator. This process takes some additional time as compared to vacuum filtration, however, the 15°C temperature is maintained.
Additional evaluation of sludge constituents in the Best Basis Inventory has been carried out. These data were obtained previously in connection with neural network evaluation activities and are now being used in an attempt to develop sludge simulants for further aluminum leaching studies. The predominant components in the SST inventory were found to be Al, Bi, Ca, Fe, and Si. Large variations exist between tanks and tank farms; consequently it was decided to examine the sludge materials within given farms. Future efforts will involve designing the sludge simulants and continuing the leaching studies.
Disposition of Idaho HLW Calcine
Support of CH2M-WG Calcine Disposition Project
The feeding systems and mixer for the mock up system have been received. We have begun final design of the test stand and will begin its construction during the next few weeks. We expect to begin shakedown testing of the mock up in October/November 2006. Two 55-gallon drums of calcine simulant (non-hazardous) shipped from INL this month have been received in good order. The statement of work and budget for CY 2007 have been provided for next year's Cooperative Agreement.
Support of SRS Salt Disposition and Other SRS Alternatives
Modeling and Experimental Support for High-level SRS Waste Disposition
The experimental systems, KNO3-NaNO3-Water, 1 and 3-m NaOH at 50°C, have been tested weekly. Solids have formed in a few of the samples but most appear to still be in solution. Additional nitrate solids will be added to these solutions in order obtain solids. The systems, CsNO3-NaNO3-Water, 1 and 3-m NaOH at 50°C, have been prepared and will follow the same regimen for equilibrium sampling. Solids have already formed in several of these solutions.
Identification of the solids from the SRS 8F sludge simulant is currently underway. XRD analysis determined approximately 50 percent by weight of the solids contained a majority of gibbsite and a smaller percentage of calcium carbonate. The remaining amorphous solids are being readied for analysis. Model predictions have these solids as iron oxide, nickel iron oxide, and magnesium oxide.
Process Improvements for the Defense Waste Processing Facility (DWPF)
On-line slurry analysis. The work on evaluating powder samples with LIBS for SRNL's new project continues. The powder samples of various composition were prepared by mixing a batch powder sample with different amounts of CeO2. Various amount of binder was added to powder samples and pressed into pellets. LIBS data from the sample from the pellet with and without binder were recorded and compared. LIBS data were also recorded from the powder sample place on a double sided tape. The calibration data from pellets and powder on tape were collected. These data are being carefully examined to determine the method that meet SRNL's needs. A report based on these measurements will be prepared and submit to 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's not what has been observed in practice. The products of these experiments are now being evaluated by differential scanning calorimetry and optical microscopy.
More experiments have been run this month to establish a reason for the above discrepancy. A paper is being prepared for the October meeting of the American Ceramic Society.
A shipment of SB4 simulant Frit 503, and Frit 418 was received this month. We have begun chemical and thermal characterization of these materials. Several experiments have also been run to compare melting rates.
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. The budget and statement of work for CY 2007 have been submitted.
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 AG-1 nuclear grade HEPA filters was continued. All testing was conducted with the three micron D50 cut-point in place using 30% KCl. Tests were completed at 428 and 357 SCFM, 7.5 and 6.3 ft/min, respectively. Much of one week was spent diagnosing a filter "leak" problem. It is suspected at this point that upstream air was escaping passage though the filter media via the filter front face gasket. Calculations of the downstream aerosol geometric mean and geometric standard deviation was performed for the above mentions runs, as well as for a a previously collected Flanders filter media velocity data set. The HEPA group hosted Andy Stillo from Camfil Farr to demonstrate our filter testing capabilities and to discuss current issues related to AG-1 HEPA filters.
Inquiries may be addressed to:Dr. Roger King, Interim Director
205 Research Blvd.
Starkville, MS 39762-5932