August 2004

DIAL's Research Highlights

Diagnostic Instrumentation & Analysis Laboratory
Mississippi State University
John Plodinec, Principal Investigator

Prepared for the U.S. Department of Energy
Office of Science and Technology
Cooperative Agreement DE-FC01-04EW54600

Task 1

Support of Closure Sites

Fernald Silos Project Monitoring and Control Integration

Waste stabilization formulation development. Formulation testing continued. During August, the primary goal of the grout testing was to develop baseline formulations and determine the operating envelope for various waste loading and total solids content values. Following the baseline development testing, grout formulations were prepared that will be employed in the event that a given grout mixture is too stiff for handling and transfer operations. These grout formulas use Advacast 500, a super-plasticizing agent. Testing with Advacast has demonstrated that its use is sensitive to the total water content of the grout mixture. Addition of too much Advacast 500 results in the formation of free water on the treated material.

Wastewater equilibration study. The wastewater equilibration study (WES) was concluded in August. Follow-up activities are being planned in order to determine treatment methods that will be employed during full-scale operations. The wastewater generated during silos mining operations must meet water requirements of the Fernald Advanced Waste-Water Treatment facility.

Settling tests. Planning has commenced for a series of settling tests using actual K-65 material. Settling tests will be performed to determine the: 1) percent solids of the supernatant; 2) percent solids of the settled material; 3) Ra-226 specific activity of the supernatant; and 4) density of the settled material. Tests will be performed for settling time intervals of 2, 8, 16, 24, and 48 hours at slurry concentrations of 5, 10, and 15% solids.

Planned activities. The following activities are planned for the upcoming months:

• Continue formulation testing with K-65.
• Begin the settling tests.
• Participate in the full-scale surrogate testing of the silos processing facility.

Accelerating Phytoremediation by Monitoring Plant Status

During the month of August, we have started to analyze samples and data for the mercury phytoremediation experiment that we finished in July. Because of the large number of samples, we expect to continue the analysis in September and possibly finish it in October.

Task 2

Support of Hanford Single Shell Tank Waste Disposition

In-tank/At-tank Characterization for Closure of Hanford Tanks

DIAL will have a conference phone call with Hanford on September 2. Part of our efforts this month involved preparing Power Point presentations to report our progress and outline our plans for the next Cooperative Agreement year.

Stereovision. During August, the Stereovision effort has been investigating the effect on stereovision performance of different parameters, such as distance between cameras, working distance, window size for disparity map computation, etc. These efforts to determine the optimum parameters for Hanford tank application will continue. Our efforts will also address issues related to design of the deployable instrumentation package.

Laser-induced fluorescence-spectral imaging. During August, the laser-induced fluorescence-spectral imaging effort has optimized the experimental configuration for collecting laser-induced fluorescence spectra of selected simple uranium and thorium compounds.

Microwave-induced plasma-cavity ringdown spectroscopy. Ringdown measurements of mercury using two different types of microwave-induced plasma sources (MIPs) (a candle-shape MIP and a tube-shape MIP) were conducted. Abundant experimental data were obtained under different plasma operating conditions. The data obtained using the two plasma sources will be directly compared in order to improve optimization of the system operation. The preliminary data show a compact MIP is very promising in terms of detection sensitivity and system operating costs.

Fiber optic sensors. During this month, we prepared samples for a test using MSU's gamma radiation source. Two flexible capillary tubes coated with ZnS-doped sol-gel silica and a ZnS-doped sol-gel silica monolith as a round disc were prepared. A literature research has been performed; it was found that ZnS and CdS quantum dots have been doped in sol-gel silica for neutron detection.

Fourier transform profilometry. The FTP probe development effort has assembled a 3-foot telescoping probe, utilizing the FTP-instrument elbow developed for WVNS and also RIC's support tower. Movie files were taken to show the current status of work and to illustrate the probe's computer-controlled movements. Two CDs contain Power Point presentation files (for all the subtasks) were generated and send to Hanford in preparation for our conference call with Hanford. Work continued on development of the control system and of the support tower. FTP measurements at simulated target distances continued. Improvement of the fringe pattern projection is underway.

Information sifting. During August, the spectral identification software was successfully installed on a Windows-based computer in order to be evaluated users other than the software developer. The results of this evaluation will be used to improve the utilization of the software by non-experts and will allow us to determine how best to integrate the use of this software with the diffuse reflectance spectroscopy systems. The graduate student working on this effort has graduated and left the effort; a replacement will need to be sought.

Process Chemistry and Operations Planning for Hanford Waste Alternatives

Equilibrium for the sodium-aluminum-nitrate/phosphate-water systems at 25°C appears to be close to completion and the remaining systems at 50°C are approaching final stages of equilibrium. Filtration equipment has been ordered so that filtering of these systems may be performed at a constant temperature.

Regressions of literature data to obtain like ion interaction parameters were performed on the following common ternary systems: OH-NO₃, OH-CO₃, OH-F, OH-P, and OH-NO₂. Additionally, regressions of experimental and literature data for NO₃-CO₃, NO₂-CO₃ and NO₂-SO₄ interactions were completed. These regressions will be merged into the next version of DIAL/MSU DBLSLTDB to be released soon. Work on modeling of the FIU pilot-scale salt cake dissolution experiments continues. Results indicate excellent agreements between predicted and experimental values with the exception of aluminum.

Task 3

Disposition of Idaho HLW Calcine

Support of INEEL Calcine Disposition Project

A batch of 5 Kg calcine simulant (70 wt% Run 17; 20 wt% SBW-HT-14, 10 wt% RSH-1) was prepared. Compositional and particle size analyses were performed. All the non-high-purity materials to be used in the waste form preparation was analyzed to detect RCRA metals. The Test Plan recipes for 100 g, 30 wt% waste loading, simulated waste forms were tested. The recipe for the grout cement worked well the first time.

The Fe-P ceramic prepared according to the recipe failed to set.We are presently investigating the effect of varying the composition of the FeP matrix, basing the tests on the literature provided by ICP-SP3 and other searches. Several waste forms have been prepared, but none set rapidly.

The hydroceramics waste form did not work well either due to a too large amount of solids for the available material. Difference in the vermiculite and metakaolin used in the hydroceramic preparation with respect to the literature materials were identified as possible causes of the problem. Analysis on the absorption properties of the vermiculite and on the amount of metakaolin that could be dissolved in the NaOH led to different formulations of the waste forms. Different curing procedures have also been investigated.

Task 4

Support of SRS Salt Disposition and Other SRS Alternatives

Support for SRS Salt Disposition Alternatives

Experimental results of viscosity measurements for the combined fractions collected during the flow through experiment for the Tank 38H simulant have been completed and are in the process of inclusion for use in porosity and permeability calculations for comparison to the model. In all combined fractions, a small amount of solids have formed. These solids, which appear to be primarily nitrate, will be identified and the weight percent also compared to model predictions. Experimental ionic profiles of the anions appear to follow the trend observed in both DASR experiments.

On-line Analysis for Defense Waste Processing Facility

During this reporting period, work continued on improving the performance of sludge sample measurement. To obtain a more reproducible LIBS signal from the slurry, system parameters such as gate width, gate delay, laser energy, diameter of the opening of the bottle containing the material, and the focus point of the beam were optimized to achieve the best signal-to-noise ratio. By fine-tuning the above parameters, a significant improved signal-to-noise ratio was obtained. To obtain the calibration data for slurry, we need more simulant from SRS. We are contacting David Peeler and Sharon Marra to identify the appropriate simulant to be sent to us. The progress will be slower next month due to lack of manpower and the samples for calibration work.

Support of Production of High Waste Loading Glasses in the DWPF

After discussions with David Peeler at SRS, DIAL has designed some experiments to examine the difference in melt rate between the two frits, 200 and 320. Experiments have begun looking at temperatures below the usual melting point of 1150°C to examine the reaction between the frits and the surrogate waste slurry (Case 7d SRAT product). These experiments are now underway.

Task 5

HEPA Filter Performance Assurance

Regenerable HEPA Filter Performance Testing

A joint project with the Department of Biological Sciences involving soot inhalation by rats was addressed during the month of August. A Lexan enclosure 2 x 1.5 x 3 feet was constructed to house the animal cages. Because the target particle size distribution includes only smaller, respirable particles, several cyclones have been built to collect the larger particles before introduction into the cage. The two cyclones made for the project were reproductions of cyclones III and V from the SRI 5-stage cyclone sampler. These cyclones have cut-points of 2 and 0.3 micrometers, respectively, for particles with a specific gravity of two at a flow rate of 1 cfm. Test runs were conducted with soot and potassium chloride (KCl) to verify the operation of the cyclones.

The dilution system used to reduce the number concentration was also developed. The first approach was to construct an eductor that would be placed immediately before the cyclones, but the back pressure on the cyclones diminished the suction to unworkable levels. Instead, two Dekati ejector diluters (intended for use with the ELPI) will be allowed to aspirate from the soot-laden air exiting the cyclones. These diluters should reduce the concentration by a factor of approximately 100; make-up air will be added to the output until the intended flow rate through the cage (about 100 L/min) is reached.

Inquiries may be addressed to: