381 Matching Results

Search Results

Advanced search parameters have been applied.

RCRA Groundwater Quality Assessment Report for Waste Management Area S-SX (November 1997 through April 2000)

Description: This report updates a continuing groundwater quality assessment for single-shell tank Waste Management Area S-SX at the Hanford Site. This report covers November 1997 through April 2000. Major new findings include the following: groundwater contamination continues to persist in both the northern half of the Waste Management Area as well as the southern half; evaluation of changes in water table elevations indicates a gradual shift in the direction of groundwater flow from the southeast to a more easterly direction; discrete depth sampling suggests mobile tank waste contaminants are at the very top of the aquifer in downgradient wells along the southeast side of the SX tank farm.
Date: February 23, 2001
Creator: Johnson, Vernon G. & Chou, Charissa J.
Partner: UNT Libraries Government Documents Department

EVALUATION OF A TECHNETIUM-99 DETECTOR BASED ON LABORATORY TESTING FOR USE IN IN-SITU VADOSE ZONE APPLICATIONS

Description: This document evaluates the feasibility of in-situ detection of technetium-99 in Hanford Site vadose zone soils (the soils between the surface and groundwater) using laboratory tests. The detector system performs adequately for high technetium concentration, but more development and laboratory testing is needed before field demonstration is performed.
Date: September 11, 2009
Creator: FM, MANN & DA, MYERS
Partner: UNT Libraries Government Documents Department

Aquifer Testing Recommendations for Supporting Phase II of the T Area Technetium-99 Data Objectives Process

Description: Aquifer characterization needs are currently being assessed to optimize pump-and-treat remedial strategies within the 200-ZP-1 operable unit, specifically for the immediate area of the 241-T Tank Farm. This report provides a general discussion of the six identified hydrologic test methods for possible subsequent characterization within the 241-T Tank Farm area and details for implementing the large-scale recovery test after terminating pumping at the 241-Tank Farm extraction well locations.
Date: April 2, 2008
Creator: Spane, Frank A.
Partner: UNT Libraries Government Documents Department

Spatial Analysis of Contaminants in 200 West Area Groundwater in Support of the 200-ZP-1 Operable Unit Pre-Conceptual Remedy Design

Description: This report documents a preliminary spatial and geostatistical analysis of the distribution of several contaminants of interest (COIs) in groundwater within the unconfined aquifer beneath the 200 West Area of the Hanford Site. The contaminant plumes of interest extend within the 200-ZP-1 and 200-UP-1 groundwater operable units. The COIs included in the PNNL study were carbon tetrachloride (CTET), technetium-99 (Tc-99), iodine-129 (I-129), chloroform, plutonium, uranium, trichloroethylene (TCE), and nitrate. The project included three tasks. Task 1 involved the development of a database that includes all relevant depth-discrete data on the distribution of COIs in the study area. The second task involved a spatial analysis of the three-dimensional (3D) distribution of data for the COIs in the study area. The main focus of the task was to determine if sufficient data are available for geostatistical mapping of the COIs in 3D. Task 3 involved the generation of numerical grids of the concentration of CTET, chloroform, and Tc-99.
Date: December 30, 2008
Creator: Murray, Christopher J. & Bott, Yi-Ju
Partner: UNT Libraries Government Documents Department

SEPARATION OF TECHNETIUM-99 FROM URANIUM HEXAFLUORIDE

Description: A system is described for recovery of Tc from UF/sub 6/ in a UO/sub 3/ fluorination plant. The Tc is retained on MgF/sub 2/ in traps through which the UF/sub 6/ stream is passed. The system is in operation at the Paducah Gaseous Diffusion Plant. (J.R.D.)
Date: January 1, 1963
Creator: Golliher, W.R.; LeDoux, R.A.; Bernstein, S. & Smith, V.A.
Partner: UNT Libraries Government Documents Department

Technetium removal: preliminary flowsheet options

Description: This document presents the results of a preliminary investigation into options for preliminary flowsheets for 99Tc removal from Hanford Site tank waste. A model is created to show the path of 99Tc through pretreatment to disposal. The Tank Waste Remediation (TWRS) flowsheet (Orme 1995) is used as a baseline. Ranges of important inputs to the model are developed, such as 99Tc inventory in the tanks and important splits through the TWRS flowsheet. Several technetium removal options are discussed along with sensitivities of the removal schemes to important model parameters
Date: October 24, 1995
Creator: Eager, K.M.
Partner: UNT Libraries Government Documents Department

Technetium getters in the near surface environment

Description: Conventional performance assessments assume that radioactive {sup 99}Tc travels as a non-sorbing component with an effective K{sub d} (distribution coefficient) of 0. This is because soil mineral surfaces commonly develop net negative surface charges and pertechnetate (TcO{sub 4}), with large ionic size and low electrical density, is not sorbed onto them. However, a variety of materials have been identified that retain Tc and may eventually lead to promising Tc getters. In assessing Tc getter performance it is important to evaluate the environment in which the getter is to function. In many contaminant plumes Tc will only leach slowly from the source of the contamination and significant dilution is likely. Thus, sub-ppb Tc concentrations are expected and normal groundwater constituents will dominate the aquifer chemistry. In this setting a variety of constituents were found to retard TcO{sub 4}: imogolite, boehmite, hydrotalcite, goethite, copper sulfide and oxide and coal. Near leaking tanks of high level nuclear waste, Tc may be present in mg/L level concentrations and groundwater chemistry will be dominated by constituents from the waste. Both bone char, and to a lesser degree, freshly precipitated Al hydroxides may be effective Tc scavengers in this environment. Thus, the search for Tc getters is far from hopeless, although much remains to be learned about the mechanisms by which these materials retain Tc.
Date: May 19, 2000
Creator: KRUMHANSL,JAMES L.; ZHANG,PENGCHU; WESTRICH,HENRY R.; BRYAN,CHARLES R. & MOLECKE,MARTIN A.
Partner: UNT Libraries Government Documents Department

Tc-99 Analysis with Picogram Sensitivity by a Resin-Bead Mass-Spectrometric Isotope-Dilution Technique

Description: This paper describes an improved isotope-dilution mass-spectrometric procedure. Important improvements are a highly selective (yet non-critical) isolation scheme devised primarily from the work of Maeck, et al. and a significant increase in the mass spectrometric ionization efficiency for technetium obtained by analyzing the technetium absorbed on individual anion exchange resin beads.
Date: March 14, 2001
Creator: Anderson, T.J.
Partner: UNT Libraries Government Documents Department

Optimization of Dedicated Scintimammography Procedure Using Detector Prototypes and Compressible Phantoms

Description: Results are presented on the optimization of the design and use of dedicated compact scintimammography gamma cameras. Prototype imagers with a field-of-view (FOV) of 5 cm x 5 cm, 10 cm x 10 cm and 15 cm x 20 cm were used in either a dual modality mode as an adjunct technique to digital x-ray mammography imagers or as stand-alone instruments such as dedicated breast SPECT and planar imagers. Experimental data was acquired to select the best imaging modality (SPECT or planar) to detect small lesions using Tc{sup 99m} radio-labeled pharmaceuticals. In addition, studies were preformed to optimize the imaging geometry. Results suggest that the preferred imaging geometry is planar imaging with two opposing detector heads while the breast is under compression, however further study of the dedicated breast SPECT is warranted.
Date: October 1, 2000
Creator: Majewski, S.; Kieper, D.; Curran, E.; Keppel, C.; Kross, B.; Palumbo, A. et al.
Partner: UNT Libraries Government Documents Department

{sup 99}Tc bioassay by inductively coupled plasma mass spectrometry (ICP-MS)

Description: A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max} beta decay product by liquid scintillation or gas flow proportional counting. In a urine matrix, the analysis of{sup 99}Tc is plagued with many difficulties using conventional radiometric methods. Difficulties originate during chemical separation due to the volatile nature of Tc{sub 2}O{sub 7} or during radiation detection due to color or chemical quenching. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard quench correction and a quench curve correction method are compared to results obtained by ICP-MS. Each method produced accurate results, however the precision of the ICP-MS results is superior to that of liquid scintillation results. Limits of detection (LOD) for ICP-MS and liquid scintillation detection are 14.67 and 203.4 dpm/L, respectively, in a real urine matrix. In order to determine the basis for the increased precision of the ICP-MS results, the detection sensitivity for each method is derived and measured. The detection sensitivity for the {sup 99}Tc isotope by ICP-MS is 2.175 x 10{sup {minus}7} {+-} 8.990 x 10{sup {minus}9} and by liquid scintillation is 7.434 x 10{sup {minus}14} {+-} 7.461 x 10{sup {minus}15}. A difference by seven orders of magnitude between the two detection systems allows ICP-MS samples to be analyzed for a period of 15 s compared to 3,600 s by liquid scintillation counting with a lower LOD.
Date: May 1, 1998
Creator: Lewis, L.A.
Partner: UNT Libraries Government Documents Department

Corrosion mechanisms of spent fuel under oxidizing conditions

Description: The release of {sup 99}Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high drip rate conditions at 90{degrees}C. Evidence from the leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of {sup 99}Tc is release in 3.7 years under unsaturated and oxidizing conditions. Two reaction pathways that have been identified from SEM are (1) through-grain dissolution with subsequent formation of uranyl alteration products, and (2) grain-boundary dissolution. The major alteration product identified by X-ray diffraction (XRD) and SEM, is Na-boltwoodite, Na[(UO{sub 2})(SiO{sub 3}OH)].H{sub 2}O, which is formed from sodium and silicon in the water leachant.
Date: September 1, 1997
Creator: Finn, P. A.; Finch, R. J.; Buch, E. C. & Bates, J. K.
Partner: UNT Libraries Government Documents Department

New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems

Description: Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.
Date: December 31, 1995
Creator: Rogers, R.D.; Bond, A.H.; Zhang, Jianhua & Horwitz, P.
Partner: UNT Libraries Government Documents Department

EVALUATION OF VADOSE ZONE TREATMENT TECHNOLOGIES TO IMMOBILIZE TECHNETIUM-99

Description: The Hanford Site End State Vision document (DOE/RL-2003-59) states: ''There should be an aggressive plan to develop technology for remediation of the contamination that could get to the groundwater (particularly the technetium [{sup 99}Tc])''. In addition, there is strong support from the public and regulatory agencies for the above statement, with emphasis on investigation of treatment alternatives. In July 2004, PNNL completed a preliminary evaluation of remediation technologies with respect to their effectiveness and implementability for immobilization of {sup 99}Tc beneath the BC Cribs in the 200 West Area (Truex, 2004). As a result of this evaluation, PNNL recommended treatability testing of in situ soil desiccation, because it has the least uncertainty of those technologies evaluated in July 2004 (Treatability Test Outline, September 30, 2004). In 2005, DOE-RL and Fluor Hanford convened an independent technical panel to review alternative remediation technologies, including desiccation, at a three-day workshop in Richland, Washington. The panel was composed of experts in vadose-zone transport, infiltration control, hydrology, geochemistry, environmental engineering, and geology. Their backgrounds include employment in academia, government laboratories, industry, and consulting. Their review, presented in this document, is based upon written reports from Hanford, oral presentations from Hanford staff, and each panel members' years of experience in their particular field of expertise. The purpose of this report is to document the panel's evaluation of various treatment alternatives with potential for minimizing contaminant migration in the deep vadose zone at the Department of Energy Hanford Site. The panel was tasked with assessing the most viable and practical approach and making recommendations for testing. The evaluation of vadose-zone treatment alternatives was conducted to be broadly applicable at a variety of locations at Hanford. However, because of limitations of time, the panel was asked to focus on one example, {sup 99}Tc contamination below the BC Cribs ...
Date: March 15, 2006
Creator: PETERSEN, S.W.
Partner: UNT Libraries Government Documents Department

TREATABILITY TEST FOR REMOVING TECHNETIUM-99 FROM 200-ZP-1 GROUNDWATER HANFORD SITE

Description: The 200-ZP-1 Groundwater Operable Unit (OU) is one of two groundwater OUs located within the 200 West groundwater aggregate area of the Hanford Site. The primary risk-driving contaminants within the 200-ZP-1 OU include carbon tetrachloride and technetium-99 (Tc-99). A pump-and-treat system for this OU was initially installed in 1995 to control the 0.002 kg/m{sup 3} (2000 {micro}g/L) contour of the carbon tetrachloride plume. Carbon tetrachloride is removed from groundwater with the assistance of an air-stripping tower. Ten extraction wells and three injection wells operate at a combined rate of approximately 0.017m{sup 3}/s (17.03 L/s). In 2005, groundwater from two of the extraction wells (299-W15-765 and 299-W15-44) began to show concentrations greater than twice the maximum contaminant level (MCL) of Tc-99 (33,309 beq/m{sup 3} or 900 pCi/L). The Tc-99 groundwater concentrations from all ten of the extraction wells when mixed were more than one-half of the MCL and were slowly increasing. If concentrations continued to rise and the water remained untreated for Tc-99, there was concern that the water re-injected into the aquifer could exceed the MCL standard. Multiple treatment technologies were reviewed for selectively removing Tc-99 from the groundwater. Of the treatment technologies, only ion exchange was determined to be highly selective, commercially available, and relatively low in cost. Through research funded by the U.S. Department of Energy, the ion-exchange resin Purolite{reg_sign} A-530E was found to successfully remove Tc-99 from groundwater, even in the presence of competing anions. For this and other reasons, Purolite{reg_sign} A-530E ion exchange resin was selected for treatability testing. The treatability test required installing resin columns on the discharge lines from extraction wells 299-W15-765 and 299-W15-44. Preliminary test results have concluded that the Purolite{reg_sign} A-530E resin is effective at removing Tc-99 from groundwater to below detection limits even in the presence of competing anions (e.g., nitrate ...
Date: November 29, 2007
Creator: SW, PETERSEN; AC, TORTOSO; WS, ELLIOTT & ME, BYRNES
Partner: UNT Libraries Government Documents Department

Aquifer Testing Recommendations for Well 299-W15-225: Supporting Phase I of the 200-ZP-1 Groundwater Operable Unit Remedial Design

Description: Aquifer characterization needs are currently being assessed to optimize pump-and-treat remedial strategies within the 200-ZP-1 Operable Unit (OU), specifically for the immediate area of the 241-TX-TY Tank Farm. Currently, 14 extraction wells are actively used in the Interim Record of Decision ZP-1 pump-and-treat system to remediate the existing groundwater contamination within this general area. Four of these wells (299-W15-40, 299-W15-43, 299-W15-44, and 299-W15-765) are targeted to remediate contamination within the immediate 241-TX-TY Tank Farm area. The major contaminant of concern (COC) for the 200-ZP-1 OU is carbon tetrachloride. Other COC’s include total chromium (trivalent [III] and hexavalent [VI], nitrate, trichloroethlyene, iodine-129, technetium-99, and tritium.
Date: March 10, 2009
Creator: Spane, Frank A. & Newcomer, Darrell R.
Partner: UNT Libraries Government Documents Department

Results of Groundwater Monitoring for the 183-H Solar Evaporation Basins

Description: The 183-H solar evaporation basins (183-H basins) were located in the 100-H Area of the Hanford Site and have been demolished and backfilled under the Resource Conservation and Recovery Act (RCRA) in the Hanford Facility RCRA Permit (Ecology 2004). Post-closure actions remain for the 183 H basins. Groundwater is monitored in accordance with Washington Administrative Code (WAC) 173 303 645(11), ''Corrective Action Program'', and Part VI, Chapter 2 of the Hanford Facility RCRA Permit (Ecology 2004). The waste discharged to the basins originated in the 300 Area fuel fabrication facility and included solutions of chromic, hydrofluoric, nitric, and sulfuric acids that had been neutralized. The waste solutions contained various metallic and radioactive constituents (e.g., chromium, technetium-99, uranium ). Between 1985 and 1996, remaining waste was removed, the facility was demolished, and the underlying contaminated soil was removed and replaced with clean fill. This is one of a series of reports on corrective action monitoring at the 183-H basins. It fulfills a requirement of WAC 173-303-645(11)(g) to report twice each year on the effectiveness of the corrective action program. This report covers the period from January through June 2006.
Date: October 31, 2006
Creator: Hartman, Mary J.
Partner: UNT Libraries Government Documents Department

A new approach to the analysis of radiopharmaceuticals. Progress report, November 1, 1987--October 1, 1988

Description: This research is designed to investigate analytical techniques that may be used in the study of both the basic chemistry and the radiopharmaceutical chemistry of the transition metal element technetium. The original submission funded in 1987 described possible new uses in this field of high pressure liquid chromatography, mass spectrometry, and resonance Raman spectroscopy. Since then the authors have added the significant capability of MS/MS measurements on isolated technetium complexes, making possible the study of individual species and fragments observed in the spectra. Another important technique which the authors began to use last year and have extended during this reporting period is the use of {sup 99}Tc NMR. A brief outline is presented of the investigations carried out in the past year, concentrating mainly upon MS and NMR.
Date: December 31, 1988
Creator: Jones, A. G.; Davison, A. & Costello, C. E.
Partner: UNT Libraries Government Documents Department