W. I. Winters and J. R. Jewett
Numatec Hanford Company

C. M. Seidel
Waste Management Federal Services Hanford Company

To support remediation of Hanford Site high-level radioactive waste tanks, new chemical and physical measurement technologies must be developed and deployed. This is a major task of the Chemistry, Analysis, Technology Support (CATS) group of Numatec Hanford Company (NHC). New measurement methods are required for efficient and economical resolution of tank waste safety, waste retrieval, and disposal issues. These development and deployment activities are performed in cooperation with Waste Management Federal Services of Hanford, Inc. (WMH) analytical services and frequently involve collaboration with vendors, universities, other site contractors, and national laboratories within the U.S. Department of Energy complex. This paper provides an overview of current analytical technologies in progress.

The high-level waste at the Hanford Site is chemically complex because of the numerous processes used in past nuclear fuel reprocessing there, and a variety of technologies is required for effective characterization. Programmatic and laboratory operational needs drive the selection of new technologies for characterizing Hanford Site high-level waste, and these technologies are developed for deployment in laboratories, hot cells or in the field. New physical methods, such as the propagating reactive systems screening tool (PRSST) to measure the potential for self-propagating reactions in stored wastes, are being implemented. Technology for sampling and measuring gases trapped within the waste matrix is being used to evaluate flammability hazards associated with gas releases from stored wastes. Application of new inductively coupled plasma and laser ablation mass spectrometry systems at the Hanford Site's 222-S Laboratory will be described. A Raman spectroscopy probe mounted in a cone penetrometer to measure oxyanions in wastes or soils will be described. The Hanford Site has used large volumes of organic complexants and acids in processing waste, and capillary zone electrophoresis (CZE) methods have been developed for determining several of the major organic components in complex waste tank matrices. The principles involved, system installation, and results from these and other new technologies will be summarized.

Unlike most other nuclear reprocessing sites, the high-level waste at the Hanford Site has been generated by a variety of major chemical processing operations. The bismuth phosphate process, responsible for most of the waste found in the Hanford Site's single-shell tanks, used bismuth phosphate and lanthanum fluoride precipitations to separate and purify plutonium from nuclear fuels. The reduction-oxidation (REDOX) process used large amounts of aluminum as a salting agent to improve the process of extracting uranium and plutonium into hexone solvent. The Hanford Site plutonium-uranium extraction (PUREX) process introduced significant quantities of iron as a reductant for plutonium. The waste fractionization process was used to remove ¹³⁷Cs and ⁹⁰Sr from the high-level waste to prevent it from overheating. Large amounts of organic complexants were used in this process to improve the selection of strontium in its extraction from waste containing transition metals. These organic compounds now give rise to concerns about uncontrolled organic-nitrate reactions in the wastes. Other smaller-scale processes, such as plutonium and uranium product processing and ferrocyanide precipitation of ¹³⁷Cs from supernatants, further complicate the chemical composition of Hanford Site tank wastes. Waste management activities such as inter-tank transfers and evaporation have created a heterogeneous mixture of saltcakes, sludges and liquids with a wide range of chemical and physical properties. The sampling and characterization of this complex waste represents a significant challenge to the Tank Waste Remediation System Characterization program and has stimulated the development of new measurement technologies.

Development of new and improved technologies for characterizing the waste are driven by both operational and programmatic needs. The characterization program in the late 1980's focused on making decisions on whether the waste should be retrieved, left in place or further characterized based on long- and short-term risk assessments of waste storage. After implementation of the Tri-Party Agreement⁽¹⁾, the waste analysis plans included characterization for regulatory criteria. These early waste analysis plans⁽²⁾ also identified technological improvements that were needed for the program. During the last five years, the tank characterization program's primary focus has been on resolution of safety issues associated with the tanks. During this time, a data quality objective (DQO) process was implemented to identify the data needed to address such concerns as: ferrocyanide reactivity, organic-nitrate reactivity, and other questions about thermal stability of wastes in storage; flammable gas generation and retention; accuracy of historical data on waste tank contents; waste retrieval, pretreatment, and disposal; and regulatory closure of the waste tanks. Development of these DQOs has identified needs for new technologies and testing methods to improve the quality and applicability of the data.

Operationally, the laboratory and characterization program are interested in collecting as much information as they can, as quickly and cheaply as possible. The sheer size of the program, the number of tanks, the amount of waste, and the complexity of sampling and analyzing the highly radioactive material safely, raises the cost of characterization and limits the amount of information that is affordable. New technology is needed to support faster turnaround times for waste retrieval and disposal operations. Measurement technologies for categorizing the wastes can be developed as suitable cost-saving alternatives to exhaustive, detailed analysis. Also, remote handling and measurement technologies often must be developed to reduce radiological exposure to workers .

The measurement systems described in this paper are highly varied. In some cases, the technology may be new only in the sense that the operation has not used the technique in the past. In other cases, the technology represents unique developments that have been designed primarily for Hanford Site applications. These technological improvements range from small devices for sample preparation costing only a few thousand dollars to large installations costing millions. The development and implementation of these new technologies demonstrates the cooperation among Hanford Site contractors, and the contractors' effective collaboration with vendors, national laboratories and universities.

As a part of evaluating hazards associated with the storage of organic complexant salts in Hanford Site high-level waste tanks, a propagating reactive system screening tool (PRSST) was developed by Fauske & Associates, Inc. (FAI), in consultation with CATS personnel, to safely perform tube propagation tests on radioactive wastes in a hot cell. A "contact temperature ignition" criterion (CTI) developed by FAI states that tank waste will not support propagation at ambient temperature where the total organic carbon (TOC) content is less than (4.5 + 0.17x_w) percent and where x_w is the percent water content. The PRSST is used to increase the understanding of organic waste physiochemical properties by evaluating the hazard of ignition followed by condensed phase propagation (point source ignition). The test apparatus illustrated in Fig. 1 consists of a thin, insulated stainless steel cylinder about 16 mm in diameter and 50 mm tall filled with the test material. The assembly is sealed in a bomb equipped with a pressure transducer to monitor gas generation during reaction. The reaction is ignited at the top, and the progress of the reaction, if any, is monitored by three thermocouples spaced 20 mm apart along the exterior length of the cylinder. One of two distinct behaviors is observed. Either the reaction proceeds to the bottom of the cylinder in samples supporting propagation, or the reaction does not ignite or fails to sustain combustion. Fauske and Associates, Inc. has used a larger, more customary apparatus to test synthetic waste mixtures and to establish boundaries for propagation summarized in the CTI. FAI worked with NHC scientists to reduce the PRSST system in size to accommodate smaller samples with reduced radiological doses, and modified the system to permit easier use in a hot cell environment. This system has been installed in the 222-S Laboratory hot cells and is presently being used to test samples. Before samples are tested they are vacuum dried at 105°C to constant weight. Tests are also being run on samples with organic spikes to verify the location of the CTI propagation boundary for actual tank wastes.⁽³⁾ Results from some of these tests are summarized in Table I.

Fig. 1. Propagating RSST Test Cell.

Measurements of the types and amounts of gases held in the convective and non-convective layers of waste in Hanford Site high-level waste tanks are needed to predict the flammability hazard if these gases were released into the tank headspace. These gas measurements are made on core samples of the wastes. Numatec Hanford Company scientists collaborated with SGN Eurisys Services Corporation, Pacific Northwest National Laboratory (PNNL), and other Hanford Site contractors in the design, fabrication and implementation of this system. The standard tank core sampler was modified to provide positive containment of the gases. The sampler is loaded in the hot cell and the end sealed to a gas extractor chamber. The sample, normally 300 mL, is extruded into the extractor (Fig. 2). The gases are extracted under vacuum with stirring. Residual gases are removed by a mercury pump until the pressure indicates no additional gases are being removed. Temperature and pressures are measured to determine the quantity of trapped gases. The collected gas samples are analyzed by mass spectrometry. Analysis of the data from this system is performed by PNNL scientists to determine the moles of retained gas, the gas species and the void fraction in the waste. These values, in turn, are used to evaluate the flammability safety conditions for the tank.^(4.5)

Fig. 2. RGS Overall Arrangement.

Knowledge of the organic complexant species is needed to better understand the energy content (fuel value) of the waste and to determine the extent of thermal and radiolytic aging of the complexants. These quantities can be used to resolve the organic safety issue. The primary complexants introduced in the waste fractionization processes at the Hanford Site were ethylenediaminetetracetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), glycolate and citrate. Degradation of these compounds has resulted in other organic species being present in the waste. Complete characterization of these organic species is difficult and requires the application of derivatization gas chromatography/mass spectroscopy, liquid chromatography/mass spectroscopy, and other measurement techniques to account for most of theTOC found in the samples.

In cooperation with Washington State University Tri-Cities, CATS has developed reverse polarity capillary zone electrophoresis methods for EDTA and HEDTA that may be performed rapidly, routinely, and cost-effectively. Organic species are separated and quantified by introducing the sample aliquot by gravity into a capillary (50 mm inner diameter, 50 cm long) filled with electrolyte, usually a pH buffer such as borate/hexamethonium bromide. A voltage, usually 10 to 30 kV, is applied across the capillary, causing migration of the charged species toward electrodes at different rates. Migration rates of the organic species can be modified by changing the electrolyte composition, polarity of charge and applied voltage. The migrating organic species are normally detected by an ultraviolet absorption spectrometer. Detection limits for EDTA and HEDTA in tank matrices are 7.8 µM and 11.5 µM respectively. Spike recoveries are between 96 percent and 115 percent for EDTA and between 75 percent and 108 percent for HEDTA. No significant interferences were observed from inorganic anions, organic compounds, or metal ions. Some CZE results for EDTA and HEDTA in tank waste are summarized in Table II.

Reverse polarity capillary zone electrophoresis is also being used to analyze for organic acids such as formate, acetate and glycolate in Hanford Site high-level waste tank samples. Formates and acetates can also be analyzed by ion chromatography. Some organic acid spike results are summarized in Table III. Ion chromatographic methods for formate and acetate compare favorably with the CZE results. Because of the better sensitivity for ion chromatography, it is the preferred method for acetate and formate. CATS scientists are working with WMH scientists to develop ion chromatography methods for other organic species of interest such as iminodiacetic acid, nitrilotriacetic acid and citrate. These methods will provide a more complete speciation of the organics found in the wastes.

Table III. Summary of CZE Spike Recoveries for Organic Acid Analyses.

The problem of obtaining representative samples from Hanford Site high-level waste tanks is difficult to resolve or control because of the great heterogeneity of the waste and the limited access points at which samples can be taken. In the laboratory, subsampling errors can be minimized by homogenizing the sample and maximizing the sample size. Over the years different systems have been used to mix waste samples:

• 1985 - Potato masher and mortar-and-pestle
• 1989 - Stomacher and high-speed rotor/stator/blade homogenizer
• 1993 - Motorized mortar-and-pestle and double planetary mixer
• 1996 - Modified rotor/stator/blade homogenizer

Working with PRO Scientific Inc. and WMH personnel, NHC scientists modified a commercially available homogenization system (PRO-400 with exchangeable rotor/stator/blade heads) to meet the design requirements outlined in Table IV.

A complex synthetic matrix containing three layers with different major and minor components was homogenized for 3 to 5 minutes using the homogenizer blade assembly. The test was carried out with wet and dry synthetic wastes. Results of major and minor components from multiple subsamples of these homogenized synthetics are summarized in Table V. Problems were encountered in homogenizing the dry sample because of difficulties in getting the blade into the dry sample and sealing the jar. Further development will be needed for this type of sample. Some general observations from these tests follow.

1. Relative percent differences for duplicate dry samples were greater than for wet samples, but <10 percent for metals in any case.
2. Relative percent differences for minor elements were comparable to the major components.
3. Total organic carbon results were good for both moisture levels.
4. Relative percent differences for differential scanning calorimetry and thermal gravimetric analysis for weight percent water were normally larger than for other analyses because of the small (~20 mg) sample sizes used in these tests.
5. Two water rinses reduced carryover of analytes to <0.1 percent.

Limited testing on actual waste samples with relatively high moisture contents indicates that in addition to the homogenization process, the method of removing two-phased samples must be carefully controlled to obtain good reproducibility.

Table V. Summary of Results for Homogenizer on Synthetic Waste Matrix.

To measure the major constituents in the waste samples, the highly radioactive aqueous solutions must be diluted prior to final measurement with the various instruments. An area of concern to the laboratory operation is performing these primary dilutions safely and accurately in open-face laboratory hoods. Historically, these dilutions have been made with manual, semi-remote tools designed and fabricated by the laboratory and employing glass micropipets or pipet tips with micrometer-actuated syringe mechanisms.

As technology improved and safety requirements increased, it was necessary to implement a new primary dilution system. Working with Cyberlab, Inc., CATS scientists are developing an automated dilution station based on an available commercial system that meets the radiological and sample handling requirements of the 222-S Laboratory. The primary objectives of the system are listed below.

1. Provide accurate primary dilutions of high-level liquid waste samples.
2. Reduce personnel exposure manual operations.
3. Provide positive confirmation of dilution using weight measurements.
4. Maintain or improve sample throughput compared to manual pipetting.

Some of the design criteria are outlined below.

Containment - Sample-handling components must fit inside a standard hood.

Exposure - Operations on radioactive material must be shielded to the maximum extent possible.

Control System - Control system electronics should be outside the maximum hood to the maximum extent possible.

Container Handling - The system must accommodate at least 90 percent of sample vials and containers used in normal laboratory operation.

Waste Minimization - Waste generation must be minimized.

Commercially Available - Replacement parts must be commercially available.

Bar Code Support - The system must have automatic sample recognition and labeling capability.

These requirements brought about several innovative features during design and implementation.

Programming - Table-driven software in a higher-order language was used to simplify programming for variation in containers and dilution requirements.

Contamination Control - The design uses modular station components and smooth surfaces. Electronics are placed outside the hood. Container caps and pipette tips are the only radioactive wastes generated.

Standardization - The system is based on a commercial robotics product with add-in components such as bar code reader and balance.

Gripper Capacity - A unique capper/decapper module and bottle transport mechanism was developed to accommodate the various laboratory container types.

This system is in the final stages of testing. Its performance is shown in Fig. 3.

An inductively coupled plasma mass spectrometer (ICP/MS) has been installed and implemented to determine metals and long-lived radionuclides in Hanford Site high-level waste. Although this technology has been available for several years, this is the first system to be available for routine analyses at the 222-S Laboratory. The ability to measure 1) heavier metals such as the noble metals with improved sensitivity, 2) long-lived beta emitters such as ¹³⁵Cs, ⁹³Zr, ⁹⁹Tc, and 3) actinides, which are difficult to determine radiochemically in high level wastes, is expected to provide significant benefit to the pretreatment and disposal programs.

The system being developed and implemented at the 222-S Laboratory is a Thermo Jarrell Ash (TJA) Plasma Optical Emission Mass Spectrometer (POEMS) with the plasma source installed in a hood for radiological containment. The POEMS consists of an inductively coupled argon plasma (ICAP) source with two detection systems: an optical emission spectrometer (OES) and a quadrupole mass spectrometer (MS). This dual detection instrument can provide a dynamic range of up to 11 decades, which can reduce sample handling, cost, and personnel exposure to ionizing radiation. Because optical emission systems are already operational in the laboratory, only the mass detection system has been implemented.

The POEMS instrument was qualified by spiking both synthetic and actual waste samples.⁽⁶⁾ Four calibration methods were evaluated for the instrument: 1) direct calibration; 2) mass response calibration; 3) isotope extrapolation; and 4) isotope substitution. These calibration methods were evaluated for several applications. Direct calibration was applied to the determination of isotopes over a broad mass region. The average spike recovery for seven isotopes over atomic mass range 59 to 238 in nine tank wastes was 96.7 ± 3.5 percent. Comparison of these results with optical emission results for analytes above the detection levels showed good agreement. Comparison of uranium results by ICP/MS, ICP/OES and phosphorimetry (Table VI) show that the ICP/MS agrees well with ICP/OES at high uranium levels. Phosphorimetry is biased low compared to the spectroscopy techniques at the high uranium levels but has been shown to agree better with ICP/MS results at lower concentrations.

An indirect mass response calibration for several heavy metals was compared to the direct calibration of the same isotopes. These results, shown in Figure 4, were very comparable except for cadmium, which is not ionized easily and shows a lower response than predicted by direct calibration. The mass response calibration was also used to evaluate the determination of actinides in tank waste. Spike recoveries for actinides using a mass response calibration in the tank waste are summarized in Table VII.

Fig. 4. Comparison of mass response and direct calibrations.

Table VII. Spike Recovery for Actinides In Hanford Site Wastes.

Another indirect calibration technique, isotope extrapolation, was used to measure radioactive isotopes of cesium. Calibration of the instrument was done with the nonradioactive cesium isotope 133. This calibration was then used to determine radioactive ¹³⁵Cs and ¹³⁷Cs. In a comparison of ICP/MS and gamma energy analysis results for ¹³⁷Cs in tank waste, the average ratio for the ICP/MS result to the gamma energy analysis result was 1.12 &plumn; 0.10. This comparison indicates that the less sensitive and less accurate ICP/MS is biased high. The reason for this bias is not fully understood. Technetium-99 was measured in the waste using another indirect technique, isotope substitution. In this method non-radioactive ⁹⁹Ru was used to calibrate the instrument for ⁹⁹Tc. This substitution proved to be quite accurate because the ionization properties of the two elements are very similar. Comparison of ⁹⁹Tc results by ICP/MS with radiochemical counting methods shows excellent agreement, with an average ratio of ICP/MS to radiochemical result of 0.99 ± 0.09.

These ICP/MS applications indicate that this technology may become the method of choice for many of the heavy elements and long-lived isotopes. Its simplicity will result in improved turnaround times, lower exposure and improved quality for many analyses.

Scientists and engineers from PNNL, NHC and WMH successfully installed and tested a laser ablation mass spectrometry (LA-ICP/MS) system designed for analysis of high-level waste solids at the 222-S Laboratory hot cells at the end of 1996.⁽⁷⁾ Pacific Northwest National Laboratory has continued work this fiscal year on the data reduction program for the system and its applicability to more routine operations. The LA-ICP/MS system is similar to the ICP/MS in its plasma and detection systems. The ICP/MS is applicable only to liquids or dissolved solids, because the sample is introduced into the plasma by normal nebulization techniques. For LA-ICP/MS, the sample is a solid and is introduced into the plasma by using an ultraviolet laser to ablate particles from the sample into an argon stream leading to the plasma. The advantage of the LA-ICP/MS system is the ability to perform elemental and isotopic analysis with a minimum of sample preparation. Because the LA-ICP/MS at 222-S Laboratory is installed in the same hot cell where the high-level samples are received, sample transfer times are also reduced.

A diagram of the LA-ICP/MS system is shown in Fig. 5. The laser is located on top of the hot cell, and the beam is focused down onto a sample in the hot cell. The laser is rastered across about a 2-mm-square area of the sample to ablate particles into the argon stream that flows through the sample holder. The argon stream is carried out of the hot cell into a hood containing a particle analyzer for evaluation of the laser performance and ablation efficiency before the stream enters the plasma and mass spectrometer. The system uses three computer systems: one for laser control, one for ICP/MS control, and another for data reduction.

Qualification of the system to establish its precision and accuracy for analyzing tank waste samples is incomplete. Technology transfer of data reduction improvements from PNNL also has not been completed. However, recent improvements have reduced data reduction times from several hours to several minutes.

Limited funding has retarded development of applications. However, the system was used this year to analyze samples of sludges from Hanford Site nuclear fuel storage basins. Samples were placed directly in the holder without any preparation. Five replicate scans were performed. Each scan consisted of rastering 4 square mm of the sample for two minutes. The data recorded for each sample was the average of the five scans.

This test clearly demonstrated the value of the LA-ICP/MS as a screening tool. Even though the samples were not expected to contain significant quantities of actinides, the semi-quantitative LA-ICP/MS analyses showed plutonium in the samples at 10 to 100 µg/g levels. The scans also indicated the presence of mercury, a fact later confirmed by atomic absorption measurements. This information can have important environmental significance and can help in making informed decisions about additional analyses of the sample. One of the objectives for analyzing the fuel basin samples was to determine the uranium isotopic ratios and ⁶³Ni concentrations. Even though the LA-ICP/MS uranium results for the three samples analyzed varied by as much as a factor of five, the isotopic ratios showed good reproducibility. Efforts to use the LA-ICP/MS to estimate ⁶³Ni concentrations were not successful because of an isobaric interference from larger amounts of ⁶³Cu in the samples.

Completion of technology transfer from PNNL and further improvements in the data reduction software are needed to permit routine investigation of additional applications. LA-ICP/MS has been proposed as a method to reduce waste generation by screening samples to determine what additional tests might be required for each sample. This approach could eliminate unnecessary analyses, but it still requires validation. It is anticipated that the technique will also be valuable to high-level waste pretreatment and disposal programs for rapid assessment of operations such as sludge washing.

The ability to monitor waste compositions directly in the tanks (in situ) has the potential to enhance decision making concerning waste disposition without extensive sampling and analysis. A Raman spectroscopy measuring head for a cone penetrometer is being developed by scientists at Lawrence Livermore National Laboratory (LLNL). For this system, Raman optics have been designed to fit in the head of the cone penetrometer. The laser source and detection system are housed in the cone penetrometer control platform and are connected to the probe by fiber optic cable. An NHC scientist collaborating with LLNL performed qualification of the cone penetrometer probe using actual tank wastes that had been archived in the 222-S Laboratory hot cell.⁽⁸⁾ The Raman probe was placed in the hot cell and connected to the spectrometer on the control platform by more than 80 meters of fiber optic cable. Spectra of over 200 samples were recorded, including 100 samples spiked for calibration. These spectra were transmitted to LLNL, where they are being

evaluated using neural network techniques. Neural network analysis of the spectra is expected to improve species identification and detection levels. Comparison of Raman spectra for a waste supernatant and a sludge waste is shown in Fig. 6. The dark sludge waste scatters less light and produces a lower signal-to-noise ratio for the measurement of nitrate. Neural network analysis of the spectra is being performed by LLNL to determine if the data quality can be improved.

The cone penetrometer originally was designed to characterize the high-level wastes directly in tanks. However, complications of tank entry will probably result in redirection of the cone penetrometer application to monitoring of the vadose zone for contaminants such as nitrate originating from leaking tanks or cribs. Some preliminary testing of the Raman probe using spiked soils indicated that nitrate could be detected near the 0.5 percent level. Laboratory Raman systems with remote probes have also been used for screening of hazardous solid wastes and have been included in transportable lab systems for field work.

The authors would like to recognize the many contributors to the projects described in this paper. PRSST - D. B. Bechtold, NHC; M. A. Beck, NHC; H. K. Fauski and T. Fitzsimons, Fauski Associates Inc.; Retained Gas Sampler - B. E.Hey and C. G. Lindschooten, NHC, J. M. Bates, PNNL, N. S.Cannon SESC, R. E. Bauer, DESH; CZE - S. G. Metcalf, NHC, A. A.Okemgbo and M.A. Bachelor, WSU- Tri-Cities, J. M. Frye, WMH; Homogenizer - R. Yacko, PRO Scientific Inc., R. Akita, WMH, R. K. Fuller, WMH; Automated Dilutor - G. L. Troyer and J. K. Watts, NHC, W. C. Meltzer, Cyberlab Inc.; ICP/MS - J. W. Ball, NHC, S. M. Parong, WMH; LAMS - M. R. Smith and J. S. Hartman, PNNL, D. M. Thornton, WMH; Raman Cone Penetrometer - K. R. Kyle, LLNL, B. A. Crawford, NHC, G. N. Boechler, SESC.

Working in cooperation with other groups, scientists in Numatec Hanford Company's Chemistry, Analysis and Technology Support group have developed and tested a wide range of measurement systems to meet the high-level waste characterization challenge at the Hanford Site. These systems are in various stages of deployment in the laboratory, hot cell facilities and the field. The development and testing of new measurement systems is important to ensure continuing process improvements are achieved in obtaining high-quality, cost-effective information about the waste.

The authors would like to recognize the many contributors to the projects described in this paper. PRSST - D. B. Bechtold, NHC; M. A. Beck, NHC; H. K. Fauski and T. Fitzsimons, Fauski Associates Inc.; Retained Gas Sampler - B. E.Hey and C. G. Lindschooten, NHC, J. M. Bates, PNNL, N. S.Cannon SESC, R. E. Bauer DESH; CZE - S. G. Metcalf, NHC, A. A.Okemgbo and M.A. Bachelor, WSU- Tri-Cities, J. M. Frye, WMH; Homogenizer - R.Yacko, PRO Scientific Inc., R. Akita, WMH, R. K. Fuller, WMH; Automated Dilutor - G. L. Troyer and J. K. Watts, NHC, W. C. Meltzer, Cyberlab Inc.; ICP/MS - J. W. Ball, NHC, S. M. Parong, WMH; LAMS - M. R. Smith and J. S. Hartman, PNNL, D. M. Thornton, WMH; Raman Cone Penetrometer - K. R. Kyle LLNL, B. A. Crawford, NHC, G. N. Boechler, SESC.

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