Monthly Research Progress
Institute for Clean Energy Technology
Support of Oak Ridge Site Closure
Characterization of Corrosion for Closure of Oak Ridge Research Reactor
In preparation for construction of the new submergible probe box, AutoCAD renderings of the box are being made. Construction of a new submergible box is necessary because, during our initial deployment of the submergible Fourier transform profilometry (FTP) system into the Oak Ridge Research Reactor (ORRR) pool in December, a detectable amount of radioactive materials were deposited onto the metal box containing our instrumentation; consequently, ORNL has retained the original metal box. The materials for fabrication of the second box have been received. A 10-gallon aquarium tank was obtained to simulated underwater image acquisition without the submergible enclosure; this facilitates optimizing instrument parameters. Planning for the next deployment into the ORRR pool continues.
Bio-availability and Speciation of Mercury in the Oak Ridge Ecosystem
In March, we continued characterization of mercury contaminated field soils from the Oak Ridge site. We have completed the study on extraction of mercury sulfide from soils and sediments. We are in the process of analyzing all data from experiments on dynamics and kinetics of mercury speciation and transformation in Oak Ridge soils at three redox conditions.
In April, we expect to finish the study on characterization of mercury in field contaminated Oak Ridge samples. We will begin to summarize the method study on improving extraction of mercury sulfide form.
Accelerating Phytoremediation by Monitoring Plant Status
During the month of March, we started a new round of phytoremediation experiments. Plants of two Indian mustard species were transferred to pots containing mercury-contaminated soil. Meanwhile, we also started a smaller experiment involving CCA and Cu. The experiments are expected to continue in the following months.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
Stereovision. During this month, we tested our new cameras under laboratory conditions. The new cameras provide greater zoom capability and better image quality, which is critical for improving stereo matching and hence higher depth resolution. For certain objects, the depth resolution is approaching 6 - 7 mm/disparity level. Meanwhile, we continue to search for the optimum experimental parameters.
Laser-induced fluorescence-spectral imaging. During March, our survey of currently available camera systems continued, in preparation for purchase of a new camera system.
Microwave-induced plasma-cavity ringdown spectroscopy. Our research effort last month included building a cw-CRDS system for characterization of the absorption cross-sections of the near-infrared C-H stretching overtone of tank volatile organic compounds (VOCs). This will help determine the measurement sensitivity and the optical configuration for the tank vapor characterization. Our infrared wavemeter has been returned to the manufacturer for repair; the wavemeter is used to determine the laser wavelength.
Fiber optic sensors. This month, our effort focused on constructing liquid core waveguide scintillating optical fibers for a test using the newly packed photomultiplier tube (PMT) detector. We prepared two scintillating fibers, and connected one of the fibers to the PMT with the shielding package. This fiber will be tested next month. In addition, we are also working on an ammonia sensor using a photonic crystal hollowcore optical fiber (PC-HOF) as a gas sample cell. We replaced our infrared laser diode and are testing the new laser diode by detecting ammonia in a gas sample.
Fourier transform profilometry. Preparations have continued for a multi-stage side-by-side comparison of our Fourier transform profilometry (FTP) system and the imaging method currently used by Hanford, video camera/CAD modeling system (CCMS). The side-by-side comparison is being performed at ICET, using an available classroom. One of the walls of the classroom is being utilized to simulate the bottom of a C-200 series Hanford waste tank. Preliminary FTP results using known (conical) targets have been obtained. We have investigated several possible methods for producing nondescript targets with a definite volume that can be determined and are light enough to be rigidly and reliably mounted on a vertical surface. On March 29, our Hanford collaborators (Drs. Steve Schaus, Gary Josephson, and Blaine Barton) visited ICET to discuss the side-by-side comparison and our future efforts for Hanford.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
After extensive revisions to the DBLSLTDB in attempting to port the database to ESP version 6.7 it was noted an earlier salt cake dissolution simulations could not be reproduced. The validation simulations previously compared favorably to experiments conducted at Hanford. Reproducibility was observed in all previous version of ESP (6.0, 6.2 through 6.5). Discussions with OLI personnel made clear that the solver was changed in going from version 6.5 to 6.7. Consequently, in believing that the problem initiated with the DBLSLTDB compilation, a considerable amount of work was extended. The problem with the 6.7 solver has resulted in delays in our application calculations (neural network and FIU large column experiments).
Attempts are in progress to port the database to the latest ESP version (7.0). Initial simulations for a salt sample from Hanford tank BY-102 resulted in agreement with the earlier calculations. Additional tank compositions are being evaluated as well as solubility envelopes for a number of important ternary systems.
Steve Schaus, Blain Barton and Gary Josephson visited the ICET laboratories on March 29. Discussions centered on software issues, neural network progress and solubility measurements. Efforts are currently underway to complete additional studies prior to the technical exchange to be held in Richland in May.
Efforts continued on neural network development. The salt cake basis set, consisting of a number of waste compositions which had previously been evaluated in the 222-S laboratory by Herting and were subsequently used for ESP database evaluation and development were compared to a recent best basis inventory for all 149 single-shell tanks. Use of a training set from the earlier salt cake dissolution work would only encompass 29 of the 149 SSTs. The SST data was then evaluated to determine the minimum and maximum values for all of the non-radioactive constituents in the inventory except for cesium and strontium. A total of 31 of the 149 tanks would be required within the training set to extend coverage to all of the SSTs. Charge reconciliations were begun for a number of the tanks. In most instances prorating the charge imbalance over the anions or the cations led to changes of less than 5%. Work is in progress to consider a number of add-ons that will be required in using a neural network from BBI starting data.
Examination of the aluminum concentrations from the Al-Na-OH solubility studies has revealed that the solutions prepared in both 5 and 7-m NaOH have not yet reached equilibrium. Additional testing at regular intervals is in progress. Work on updating the DBLSLTDB database is in progress.
Disposition of Idaho HLW Calcine
Support of CH2M-WG Calcine Disposition Project
We made a comparison of the 1:1:1 formulation with and without sodium sulfide. Those made without the sulfide were not set well enough to be tested at seven days for compressive strength, were only half as strong as those made with the sulfide at 28 days, and failed the TCLP.
We made an extra large batch of the 1:0.5:0.5 formulation to see just how long it took for it to become "unpourable". After 17 minutes, the material became very stiff. It seemed to happen rather quickly, because at 16 minutes it was still reasonably pourable.
We made extra large batches from the 17% and 34% waste loading formulations and poured cylinders of four inches in diameter and eight inches tall. Upon disassembling them after curing for one week, each looked reasonably homogeneous except for a half-to-one inch region at the top and bottom of the 34% cylinder and the bottom of the 17% cylinder. The middle of the 34% sample was still wet, and probably therefore not completely cured. The bottom of the 17% one was softer than the top. We will do some elemental analysis of the various regions to better assess the homogeneity.
A draft of the Final Stabilizer Development Report has been issued for comment. Comments have been received and the report will be issued in April.
We have begun obtaining estimates for equipment for the mock-up and have started discussing among ourselves just what the equipment ought to do and how it all fits into a test plan. We should be on time to meet the various schedule milestones. Informal estimates for the feeding equipment for the mock-up seem high, so we will be adjusting our specifications for the official request for bid to see about obtaining a lower price. A request for bids on the feeder equipment for the pilot scale test has been issued.
Support of SRS Salt Disposition and Other SRS Alternatives
Modeling and Experimental Support for High-level SRS Waste Disposition
Modeling of the FIU aged 41H SRS simulant using the adjusted flow-sheet for the dissolution portion of the experiment demonstrates good agreement with the nitrite and nitrate ion concentrations. FIU recently relayed a portion of the solids analysis and further modeling of the experiment is underway. Due to problems associated with ESP version 6.7, version 6.5 has been employed for this experiment.
Preliminary results from the FIU aged 41H SRS simulant using the adjusted flow-sheet, 38H simulant with 3% sludge experiment, and CsNO3-NaOH-Water solubility at 25°C were presented to the Hanford group on their recent site visit.
A paper was submitted and accepted for publication in Separation Science and Technology for work performed on SRS 38H and 37H Simulants and the differing flow sheet models.
Process Improvements for the Defense Waste Processing Facility (DWPF)
On-line slurry analysis. The work on setting a dual-pulse LIBS system in slurry measurement to improve LIBS analytical figure of merit is delayed. The selection of the laser system for the dual-pulse LIBS is complete. However, the bidding process is temporarily on hold due to ICET budget problems.
A paper entitled "Slurry Product Analysis with Laser-induced Breakdown Spectroscopy" was presented at the 2006 Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, March 12 - 17, held in Orlando, FL.
An updated version of the data acquisition program for the Echelle spectrometer was obtained from LLA Instruments GmbH. The new version software allows us to effectively control the laser firing during data acquisition which will reduce unnecessary laser firing during data processing and storing. Various tests with a glass sample using the Echelle spectrometer and this new version software are being conducted to obtain the efficient and reliable way for slurry measurement. While testing the Echelle spectrometer, we have also conducted slurry measurements with the narrow band spectrometer for Na and Mg calibration. Due to the limited spectral coverage of this spectrometer (20 nm), we have to perform the calibration for these two elements separately in two different spectral regions. However, this system allows us to achieve good quality LIBS slurry data with much faster data acquisition. The recorded slurry spectra will be tested with different data processing methods.
Support of the Fernald Silos Project
Fernald Silos Project - Remediation Process Support
Charlie Waggoner and Brian Kauffman met with Fernald management in March to discuss the final closure issues that ICET may be able to assist with. The Silos Project K-65 processing was scheduled to be complete by the end of March. In addition, final property disposition was discussed with Fernald project personnel.
All material were surveyed and removed from the Fernald building. All trash, tools, and equipment that reside in the glove boxes were sealed in plastic bags. The interior of the gloveboxes was decontaminated to the extent possible in preparation for dismantlement.
The following activities are planned for the upcoming months:
HEPA Filter Performance Assurance
Regenerable HEPA Filter Performance Testing
Progress on this task will be reported next month.
Inquiries may be addressed to:Dr. Roger King, Interim Director
205 Research Blvd.
Starkville, MS 39762-5932