DIAL's Research Highlights
Diagnostic Instrumentation & Analysis Laboratory
Support of Closure Sites
Fernald Silos Project Monitoring and Control Integration
Waste stabilization formulation development. Formulation testing continued. During January, the primary goal of the grout testing was to determine if low waste loading grout formulations pass the waste acceptance criteria. Samples were prepared at waste loadings between six and fourteen percent. The initial testing of low waste loading grout formulations showed that the grout product becomes more sensitive to measurement, as well as random variation in the mix. Many samples showed no evidence of free water after twenty four hours, however, the samples did not pass a Vicat test for set. The following activities are planned for the upcoming months:
Accelerating Phytoremediation by Monitoring Plant Status
During the month of January, we have been analyzing samples and data from experiments finished in the last calendar year. We have also been preparing and revising manuscripts for publication.
Bio-availability and Speciation of Mercury in the Oak Ridge Ecosystem
We had our first meeting on design of the full scale test bed, which aims to simulate both terrestrial and aquatic ecosystems in Oak Ridge, TN. At the same time, we summarized the study on optimization of inductively coupled plasma atomic emission spectroscopy for measuring mercury in both contaminated soil and plants. The method was compared with cold vapor atomic absorption spectroscopy and inductively coupled plasma mass spectroscopy. The manuscript will be submitted for publication soon. In February, we will continue our design of the test bed and analytical efforts for the experiments done from last fall.
Support of Hanford Single Shell Tank Waste Disposition
In-tank/At-tank Characterization for Closure of Hanford Tanks
Stereovision. During January, the stereovision effort has initiated work on two significant development efforts. As part of the first effort, stereovision 3-D reconstructions were utilized to obtain our first estimations of volume. The second effort is development of non-epipolar global matching algorithms for determination of disparity maps from stereovision images.
Laser-induced fluorescence-spectral imaging. During January, the LIF-SI effort has concentrated on diagnosing problems associated with the reproducibility of the intensity of spectra recorded with the CCD camera/ spectrometer system. The efforts are on-going.
Microwave-induced plasma-cavity ringdown spectroscopy. Efforts this month focused on optimizing the ringdown cavity configuration and the detection electronics to obtain stable and reproducible baseline measurements. Further characterization of the electronic control of the new blue diode laser to be utilized for isotopic measurements has also been performed. The stability and reproducibility of the baseline measurements have been greatly improved, but not yet optimized.
Fiber optic sensors. During January, the emission spectra of CdSe/ZnS quantum dots doped in PDMS, PMMA and in toluene solutions have been recorded and compared. Test results indicate that the peak emission wavelength of the quantum dots in these media is very similar. Therefore, it is believed that the quantum dot doped in these polymers sustained its original structure. Further work will focus on testing the response of quantum dots to high-energy particles.
Fourier transform profilometry. During January, the Fourier transform profilometry probe effort continued work on reducing the weight of the utility light and mirror for the camera. Fabrication of the probe support tower module also continued. Software development for FTP probe motion control has started. Target images have been acquired using the optimized version of the FTP probe's elbow section. Analysis of the images will follow. Possible target measurements that may be encountered in a Hanford tank have been simulated. More measurement scenarios will be simulated.
Process Chemistry and Operations Planning for Hanford Waste Alternatives
Extensive modeling calculations of the 2003 FIU unsaturated salt cake dissolution experiment was performed. Initial efforts centered on the preparation of the salt cake and the subsequent evaluation of the model predictions compared to the experimental results. With regard to the experimental results large decreases followed by increases were found for nitrate and sodium concentrations as a function of dilution. These trends combined with a decrease in the density of the fractions collected from 1.4 to 1.2 g/cc thereafter increasing to 1.3 g/cc as dilution proceeded are indicative of channeling within the salt matrix. Options for effective modeling of channeling are under consideration.
Data for the solubilities of Al, OH, Na, NO2 , and NO3 are being collected for porting into a neural network. Data from the literature and ESP model simulations will be used. Discussions with engineers at Hanford continue with regard to access to the neural network software.
All of the 25°C and 50°C series of Al/PO4 have been filtered. Analysis is ongoing of the solids and filtrates. All of the solubility studies for the aluminum-nitrate system have also been completed. Analysis of the samples is in progress in the DIAL analytical laboratories.
Flexible Scintillating Optical Fiber Sensor for Determination of Liquid Level
During this reporting period, the emission spectra of CdSe/ZnS quantum dot doped PMDS and PMMA were compared to the spectrum of the same quantum dots in a toluene solution. The peak emission wavelengths of the two polymeric materials were very similar to that of the solution based measurement. This similarity seems to indicate preservation of the original quantum dot structure during the doping process, making these materials ideal for sensing high energy particles. Future efforts will be focused toward testing the response of the quantum dot doped materials to high energy particles.
Disposition of Idaho HLW Calcine
Support of INEEL Calcine Disposition Project
Progress on this task will be reported later.
Support of SRS Salt Disposition and Other SRS Alternatives
Support for SRS Salt Disposition Alternatives
Traditional homogeneous modeling of the 37H DASR experiment showed no unusual dissolution followed by dilution anion profiles while the experimental results demonstrated significant deviation from the model for the nitrate and carbonate anions. As with the previous DASR experiments on the 38H tank simulant, a different approach with the modeling is currently being investigated. Several experiments were designed and prepared to mimic the 37H tank waste for isolation of either hydroxysodalite or cancrinite solids at ambient temperature. These experiments were repeated to make sure the systems are at equilibrium.
Calculations were performed at the request of SRS engineers to examine a potential transfer of dissolved salt solution from tank 41H to 49H. Compositions based on laboratory analysis were used and indicated that cancrinite is present in the 41H waste as well as in the waste from 49H. Addition of the 41H stream to the 49H stream did not, however, result in any additional cancrinite formation.
On-line Analysis for Defense Waste Processing Facility
Initial test of the sludge sampling system shows that the venturi attached in the sampling system needs some modifications to ensure reproducible flow. This is needed to produce stable pulse-to-pulse LIBS signal. The modification in venturi is completed and the modified system is being tested with the RIC slurry with different pumping rates. The probe can be aligned in either horizontal or vertical position for the slurry measurement. During this work period, the pulse generator used in LIBS measurement was not working and has been sent to the company for repair. We will setup the double pulse LIBS measurement for slurry when the pulse generator is repaired. To improve the accuracy of Li concentration measurement, work continued on the study of the effect of self-absorption of Li lines from the glass samples of different Li concentrations. The correction of the line intensity due to self-absorption based on the spectral line shape fitting and the theoretical curve-of-growth methods were evaluated. Initial results show that both methods have some limitation in practical application. More work of this type will continue.
HEPA Filter Performance Assurance
Regenerable HEPA Filter Performance Testing
Testing of Porvair filters was performed during January. This testing included challenging these filters with RIC surrogate at both low (15% - 20%) relative humidity and high (> 60%) relative humidity. The RIC surrogate solution was fed to the atomizing nozzle using a peristaltic pump.
Additional tests were performed to look at the effect of concentration on particle size distribution. The solution concentrations were 0.3%, 3%, and 30%. The different types of solutions were sugar, salt (potassium chloride), and FeSO4 . The results from these tests are being analyzed.
Inquiries may be addressed to:Dr. John Plodinec, Director
205 Research Blvd.
Starkville, MS 39762-5932