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 February by the unexpected departure in December of the graduate student working on this effort. The stereovision effort is currently seeking a graduate student to take on this project.
Fourier transform profilometry. During February, the Fourier transform profilometry (FTP) group expended considerable effort to enhance our fundamental understanding of the manner in which real-world obstacles limit the ability of the FTP technique to obtain surface profile data with sufficient accuracy for determination of Hanford tank residual waste volumes. The previously proposed "Stage II" series of FTP performance evaluation experiments was designed to determine the FTP technique's ability to stitch together volume contributions from tank regions that fall in adjacent and overlapping images. Preliminary experiments were performed to identify unanticipated problem areas in the proposed stitching procedure. Through these experiments, a couple of limitations in the proposed stitching procedure were identified. First, we determined that it is preferable not to have the stitching boundary extend to the edge of an image, but that it is better to have the boundary fall approximately halfway into the overlap region. This avoids anomalies that occur in the transform procedure near the image edges. The second limitation is the ability to accurately determine the relative image positions and thus accurately predict the geometry of the image overlap regions. This depends on the ability to determine the "pan" and "tilt" angles with adequate resolution. An estimate of the waste volume uncertainty due to errors in "pan" and "tilt" has been obtained for the S-100 series tank. Assuming angle measurement uncertainties of ~ 0.02 degree, we obtain a waste volume uncertainty of ~2 - 2.5%. Preparations for the start of the "Stage II" series of experiments are underway, including: (1) improvements in the determination of "pan" and "tilt" angles; and (2) synthetic generation of overlapping FTP images and subsequent FTP profile and volume analysis. The use of synthetic images enables us to investigate the inherent performance of the current FTP analysis software with ideal data.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
Additional discussions with Hanford engineers concerning details of the H2 model took place. The primary data for the model arises from the Best Basis Inventory (BBI). As a first step the current model calls a file containing waste loadings and physical properties and then operates on the waste streams (177) within the file using wash and leach factors to determine the solid liquid equilibrium. Waste transfers are then considered as well as the routing of compositions to treatment facilities such as bulk vitrification, and to the waste treatment plant. The use of the neural network is intended to supplant some of the wash and leach factors such that more accurate information on the solid and aqueous phases will result. Additional BBI files were received and these were then processed such that the data could be reconciled for charge balance. An electroneutral stream is required for the thermodynamic calculations. Reconciliations were performed using changes in hydroxide and changes in sodium loading. Balancing using hydroxide resulted in negative OH concentrations for five of the tanks. Reconciling with sodium resulted in significant mass added to some of the tanks. Owing to the later problem and the fact that sodium acts as a diluent in the glass-making process a third option, consisting of prorating both the cation and the anion concentrations by a calculated percentage was performed. This process has the advantage of partitioning the charge imbalance over all of the cations and all of the anions thereby limiting the overall change in mass for a given waste composition. The process is currently being automated and a means to develop the associated molecular stream necessary for input to the thermodynamic models has been developed and tested. These data will be collected in a spreadsheet from which data can be called using the scripting software for the model. This will permit batching the data and automatic running of the code relieving the difficulties of training the neural network over limited data ranges.
Disposition of Idaho HLW Calcine
Support of CH2M-WG Calcine Disposition Project
The feeders, mixers, and control equipment have been installed on the test stand for the mock up system. A small test batch consisting of sand was used to check the operation of the feeders. No problems were encountered. A safety review is being prepared and will be completed before the first shakedown tests which will be run in early March.
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 prepared in water, 1-m and 3-m NaOH solutions at 25°C have been completed. Results from these systems were compiled and presented as a poster for the 2007 Mississippi Academy of Sciences annual conference held on the Mississippi State University campus on February 21 - 23, 2007. These systems at 50°C are currently being evaluated.
Process Improvements for the Defense Waste Processing Facility (DWPF): On-line Analysis
Work is concentrated on the subtask of analyzing the plutonium oxide residues. A fiber optic configuration to deliver the laser pulse and to create plasma spark on the sample surface was tested. Since a sufficient amount of laser energy must be delivered to the sample surface to produce breakdown, damage on the input surface of the fused silica fiber by a high pulse energy laser occurred and resulted in low transmission efficiency. We are testing the various optical configurations to avoid the damage on the input surface of the fiber and also on improving the fiber transmission efficiency. The possibility of using a hollow-core fiber to deliver the nanosecond Nd:YAG laser pulse for long term operation was explored. Since the sample in the test facility will be in pellet form (without binder) and retained in its press container during measurement, we are studying the experimental parameters to achieve the best experimental condition for these types of sample. The effects on LIBS data of laser energy, lens-to-sample distance, and pressure applied to the sample to form pellet are being studied. Based on the preliminary data, a new pellet container was designed and is being fabricated.
Process Improvements for the Defense Waste Processing Facility (DWPF): Improvement of Waste Throughput
Nothing to report.
Process Improvements for the Defense Waste Processing Facility (DWPF): Melter Monitoring
The fabrication of a mock-up of the Cold Cap Evaluation Furnace (CEF) has been started. The initial thrust is to redesign the top with appropriate window locations in order to provide access for diagnostic instrumentation. A proper field of view for the stereovision cameras is most critical.
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. ICET's 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
Construction of the test stand for testing large regenerable CeraMem filters was finalized. The filters will be challenged by pulling a slipstream of aerosol from the larger ICET HEPA filter test stand. The control system was automated and interfaced to existing data logging software. An initial test was performed to detect any problems with the system. Although the primary method of regeneration for these filters will be air-back pulse, an apparatus that will facilitate aqueous regeneration was constructed.
The filters will be tested at approximately six scfm with an initial pressure drop of approximately five inches water column.
The manuscript "Load-wash Testing of Regenerable Sintered Metal and Ceramic Membrane Filter Media" was revised based on the comments of three reviewers. The manuscript was re-submitted to Environmental Engineering Science.
Bio-availability Studies of Mercury and Other Heavy Metal Contaminants in Ecosystems of Selected DOE Sites
The kinetics of mercury release from Oak Ridge soil contaminated with HgS by complexing EDTA and oxalate solution were studied this month. We compared the extractability of pure chemical HgS and soil HgS. The results showed that chelate EDTA solubilized soil HgS from contaminated Oak Ridge soil, while extractability of pure chemical HgS by EDTA was much less than soil HgS.
In March, we will start new experiments on reaction kinetics of soil HgS with Fe/Mn oxides, elemental S and sulfide, which are possibly triggering the increase of Hg concentrations in Oak Ridge site.
Phytoremediation and Long-term Monitoring of Selected Heavy Metal and Radionuclide Contaminants
We started a new round of phytoremediation experiments using our homemade chamber. Chinese brake fern was grown on clean soil, but the plant shoot was enclosed into a chamber that containing mercury contaminated soil (with no direct contact to the plant). Our objective is to investigate the possible leaf uptake of mercury vapor from atmosphere above contaminated soil. The experiment is expected to finish in coming month(s). Meanwhile, we have been analyzing samples and data from previous experiments.
Development of New Technologies for DOE Site Applications
A prototype ringdown spectrometer for CO2 and CH4 and 13C isotope was assembled. Tests of the instrument ruggedness were performed last month. Efforts this month were focused on testing the instrument sensitivity. The 12CO2 + air and 13CO2 + air have been tested in the range of 10% - 0.1%. Next study includes measurements of the mixture of 12CO2 and 13CO2 in different isotopic ratios.
Development of Fiber Optic Sensor Technologies for DOE Site Applications
Work focused on developing a fiber optic sensing technique for detecting mercury in air at DOE's waste sites. Two sensing techniques are under development. The first fiber optic sensing technique uses our LCW fiber optic technique. Experimental results obtained during this month indicate that the LCW fiber optic technique can detect mercury in solution sample down to ten ppt. The second technique employing nanometer gold particles immobilizes porous silica for sensing elementary mercury. The absorption of mercury onto the gold particles changes the gold particle's plasma absorption spectrum, which can be detected as a sensing signal. We prepared gold nanometer particles this month.
We submitted two pre-proposals in response to RFP#: DE-PS02-07ER07-18. We also submitted our final technical/scientific report for our NETL funded project. In addition, we submitted one paper regarding our high temperature ammonia gas sensor to Analyst, and one paper describing our work on the fiber optic H2S sensor to Sensors and Actuators for publication.
Inquiries may be addressed to:Dr. Roger King, Interim Director
205 Research Blvd.
Starkville, MS 39762-5932