Monthly Research Progress
Institute for Clean Energy Technology
Support of Oak Ridge Site Closure
Characterization of Corrosion for Closure of Oak Ridge Research Reactor
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 was deposited onto the metal box containing our instrumentation; consequently, ORNL has retained the metal box, but released the rest of our equipment to us following radiological survey of the equipment. As part of our preparation efforts for a second deployment into the ORRR pool in June, we have redesigned the submergible box. All the walls (except one) of the new submergible box will be the same as in our first submergible box. The front plate is now interchangeable to permit future Stereovision implementation. During June, not only will FTP data be collected, but also Stereovision data so that we will have independent determinations. Materials for fabricating the second submergible instrument box have been ordered. Planning for the next deployment into the ORRR pool continues. A paper entitled "Quantitative Imaging Evaluation of Corrosion in Oak Ridge Research Reactor Pool" by Ping-Rey Jang, Rangaswami Arunkumar, Zhiling Long, Melissa A. Mott, Walter P. Okhuysen, Yi Su, David L. Monts (DIAL), Paula G. Kirk (ORNL), and John Ettien (Bechtel Jacobs Co.) was presented at the 32nd Waste Management Symposium, Tucson, AZ, February 27 - March 2, 2006. This paper described our development efforts and our initial deployment into the ORRR pool.
Bio-availability and Speciation of Mercury in the Oak Ridge Ecosystem
In February, we started characterization of mercury contaminated field soils from Oak Ridge site. We also initiated the study on extraction of mercury sulfide from soils and sediments. In our previous study, we identified some problems with the analytical method developed by Revis, et al, (1989) at Oak Ridge Research Institute when it is applied to a wide range of contaminated soils. This month, our mercury manuscript entitled "Binding, Distribution, and Plant Uptake of Mercury in a Soil from Oak Ridge, Tennessee, USA" was accepted by Science of Total Environment (in press). In March, we will finish the study on characterization of mercury in field contaminated Oak Ridge samples. We will also finish the method study on improving extraction of mercury sulfide form.
Accelerating Phytoremediation by Monitoring Plant Status
During the month of February, we have been carrying on a new round of phytoremediation experiments. We have grown some vegetation including two Indian mustard species, and two Oak Ridge native grass species. Pot-study will start in early March. The plants will be transferred to pots containing mercury-contaminated soil. Meanwhile, we have been analyzing samples and data from previous experiments.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
Stereovision. The stereovision effort has continued its effort to compare different approaches, such as SAD (sum of absolute differences), SSD (sum of squares of differences), and other matching algorithms, such as NCC (normalized cross correlation coefficient). The comparison is based upon both computational cost (time) and matching quality. Both experimental images from our lab and some ground-truth images published by others are being used for these comparisons. These results will allow us to determine the optimum approach for utilization of stereovision in Hanford waste tanks.
Laser-induced fluorescence-spectral imaging. During February, the LIF-SI effort began surveying currently available camera systems in order to develop specifications for purchase of a new camera system.
Microwave-induced plasma-cavity ringdown spectroscopy. The cavity ringdown spectroscopy research efforts during February focused on a literature survey of the tank vapor chemicals and an estimation of the measurement sensitivity and accuracy. This research will help to finalize the required specifications of a tunable near-infrared (NIR) light source that is to be purchased for Hanford tank vapor characterization.
Fiber optic sensors. This month, the fiber optic sensors effort focused on building an optical fiber ammonia sensor, using a photonic crystal optical fiber (PC-HOF) as a sample cell and a diode laser as the light source. We purchased PC-HOFs, a laser diode (1.55 mm) and two photodiodes. The laser diode, PC-HOF and photodiodes have been set-up in our laboratory for experiments. The light from the laser diode has been coupled into the PC-HOF. The light guided through the hollow optical fiber has been detected with a photodiode.
Fourier transform profilometry. The draft of a multi-stage side-by-side comparison of Fourier transform profilometry (FTP) and the imaging method currently used by Hanford, Video Camera/CAD Modeling System (CCMS), was prepared and sent to our Hanford collaborators for their comments and suggestions, which have been incorporated into a revised test plan. The side-by-side comparison will be performed in-house at ICET using an available auditorium. One of the walls of the auditorium will be utilized to simulate the bottom of a C-200 series Hanford waste tank. In preparation for the side-by-side comparison, we have fabricated targets (including both known and unknown) and a support for the targets. The configurations for the first-stage comparison have been chosen. Plans are refined through our bi-weekly conference calls with our Hanford collaborators.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
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 up the larger batches of the 1:1:1 formulation this week: two batches of six, half of each to be tested at seven days and half at 28 days. One batch was made (as usual) with sodium sulfide and the other without. Compressive testing (after seven days) was done on only the batch with sodium sulfide. Those made without sodium sulfide had not completely set as they were soft to the touch. (We'll save them for 28-day testing after they've set.) The results:
We have begun assessing the materials needed to build the mock-up system. Quotes are being obtained and a general overview of what will be needed is being sketched out. Some items may be long lead time, so we are beginning to rough out a time line for the procurement process.
Compressive testing was done for the 1:1:1 formulation made last month. Here are the 28-day results:
Support of SRS Salt Disposition and Other SRS Alternatives
Modeling and Experimental Support for High-level SRS Waste Disposition
The DASR small column experiment results have been received and modeling of the process has begun. Solids identification of the sludge components is underway. The weight percent of solids in the collected fractions is within a range of 1 - 13%. Preliminary analyses of the aqueous fractions indicate similar results to the previous 38H DASR experiment with the exception of an extended dissolution (3X) time frame. This additional time could be attributed to the lower porosity of the sludge/simulant.
Modeling of the FIU aged 41H SRS simulant does not follow the typical flowsheet preparation or dissolution processes. Collaboration with FIU continues on results and experimental conditions. We are awaiting solids identification of the beginning salts to establish the simulant proper.
Process Improvements for the Defense Waste Processing Facility (DWPF)
On-line slurry analysis. To improve the LIBS analytical figure of merit, this year we plan to set up and test a dual-pulse (DP) broadband LIBS system in slurry measurement. Work on selecting a laser system that can provide the proper pulse delay between the two laser pulses for dual-pulse LIBS is in progress.
Work on collecting calibration data for simulated melter feed continued. Since the long data acquisition time associated with our current broadband Echelle spectrometer will consume too much slurry, we decided to perform the slurry study with a narrow band detection system (SPEX 500M, 20-nm spectral coverage) that can perform much faster data acquisition than with the Echelle detection system. Good quality LIBS slurry data between 330 and 670 nm were obtained with this spectrometer, and we are able to obtain Li and Na calibration data with this spectrometer. However, we found that the system has poor detection sensitivity for 200 - 300 nm, which contains some important analyte lines (e.g., Si, Mg, M, etc.) for slurry analysis. The SPEX 500 spectrometer was replaced with the HR460 spectrometer equipped with an intensified CCD detector to record the data below the 300-nm spectral region. A Mechelle broadband spectrometer was lent by Andor Technology for evaluation. This detection system is very compact and can simultaneously detect a spectral range of 200 - 950 nm. We are comparing its system response time, spectral resolution, and capability to control laser firing with our current broadband and narrow band detection systems.
Improvement of waste throughput. A series of experiments has been set up to examine the evolution of interactions between frits 200 and 320 and the SRAT Case 7d waste simulant. The experiments have been run over a temperature range of 600°C to 800°C for times of 15, 30 and 60 minutes. Differential scanning calorimetry (DSC) has been completed of all samples created in these experiments and comparisons are being made of these analyses. Optical microscopy of these materials will be completed during March.
Support of the Fernald Silos Project
Fernald Silos Project - Remediation Process Support
We began decommissioning the glove boxes during February. Dr. Waggoner and Brian Kauffman have a visit scheduled to the site in March. The purpose of the visit will be to discuss additional work.
HEPA Filter Performance Assurance
Regenerable HEPA Filter Performance Testing
During the month of February, we began writing three manuscripts. Two manuscripts, "Lifetime Testing of Sintered Metal and Ceramic Membrane Regenerable Filter Media" and "Evaluation of Glass Fiber HEPA Filters as a Function of Media Velocity", will be submitted for publication in the proceedings of the International Conference on Incineration and Thermal Treatment Technologies. A manuscript entitled "HEPA Filter Performance under Adverse Conditions" will be submitted to a an undetermined peer-reviewed journal. In addition to writing the manuscripts, analysis of the data contained therein was conducted. Writing and data analysis will continue into March.
Inquiries may be addressed to:Dr. Roger King, Interim Director
205 Research Blvd.
Starkville, MS 39762-5932