Michael J. Lindberg

Characterization of Vadose Zone Sediment: Borehole 299-E33-45 Near BX-102 in the B-BX-BY Waste Management Area

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.22. The data was removed due to potential contamination introduced during the acid extraction process. The remaining text is unchanged from the original report issued in 2002. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area B-BX-BY. This report is the first in a series of four reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole 299-E33-45 installed northeast of tank BX-102.

Characterization of Vadose Zone Sediment: RCRA Borehole 299-E33-338 Located Near the B-BX-BY Waste Management Area

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.8. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in June 2003. The overall goals of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are: 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid via collection of geotechnical information and data, future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank waste management areas. For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at the B-BX-BY tank farm waste management area are found in CH2M HILL (2000).

Characterization of Vadose Zone Sediments Below the TX Tank Farm: Boreholes C3830, C3831, C3832 and RCRA Borehole 299-W10-27

This report was revised in September 2008 to remove acid-extractable sodium data from Tables 4.8, 4.28,4.43, and 4.59. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in April 2004. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area (WMA) T-TX-TY. This report is the first of two reports written to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from boreholes C3830, C3831, and C3832 in the TX Tank Farm, and from borehole 299-W-10-27 installed northeast of the TY Tank Farm.

Hanford Tanks 241-C-203 and 241-C-204: Residual Waste Contaminant Release Model and Supporting Data

This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.

Dissolution Kinetics of Titanate-Based Ceramic Waste Forms: Results from Single-Pass Flow Tests on Radiation Damaged Specimens

This report is a summary report in which the data from the single-pass flow-through test on resintered 238Pu-bearing ceramics are reported. These results show that radiation damage has litte effect on the dissolution kinetics of candidate titanate ceramics for plutonium immobilization.

Hanford Tanks 241-AY-102 and 241-BX-101: Sludge Composition and Contaminant Release Data

This report describes the results of testing sludge samples from Hanford tanks 241-AY-102 (AY-102) and 241-BX-101 (BX-101). These tests were conducted to characterize the sludge and assess the water leachability of contaminants from the solids. This work is being conducted to support the tank closure risk assessments being performed by CH2M HILL Hanford Group, Inc. for the U.S. Department of Energy. This is the first report of testing of BX-101 sludge and the second report of testing of AY-102. Lindberg and Deutsch (2003) described the first phase of testing on AY-102 material.

Characterization of Vadose Zone Sediments Below the C Tank Farm: Borehole C4297 and RCRA Borehole 299-E27-22

The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area (WMA) C. This report is the first of two reports written to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole C4297, installed adjacent to Tank C-105, and from borehole 299-E27-22, installed directly north of the C Tank Farm. Sediments from borehole 299-E27-22 were considered to be background uncontaminated sediments against which to compare contaminated sediments for the C Tank Farm characterization effort. This report also presents our interpretation of the data in the context of sediment types, the vertical extent of contamination, the migration potential of the contaminants, and the likely source of the contamination in the vadose zone and groundwater below the C Tank Farm. The information presented in this report supports the A-AX, C and U Waste Management Area field investigation report(a) in preparation by CH2M HILL Hanford Group, Inc. A core log was generated for both boreholes and a geologic evaluation of all core samples was performed at the time of opening. Aliquots of sediment from the borehole core samples were analyzed and characterized in the laboratory for the following parameters: moisture content, gamma-emitting radionuclides, one-to-one water extracts (which provide soil pH, electrical conductivity, cation, trace metal, and anion data), total carbon and inorganic carbon content, and 8 M nitric acid extracts (which provide a measure of the total leachable sediment content of contaminants). Two key radiocontaminants, technetium-99 and uranium-238, along with other trace metals were determined in acid and water extracts by inductively coupled plasma mass spectrometry.

Hanford Tank 241-C-106: Impact of Cement Reactions on Release of Contaminants from Residual Waste

The CH2M HILL Hanford Group, Inc. (CH2M HILL) is producing risk/performance assessments to support the closure of single-shell tanks at the U.S. Department of Energys Hanford Site. As part of this effort, staff at Pacific Northwest National Laboratory were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. Initial work to produce release models was conducted on residual tank sludge using pure water as the leaching agent. The results were reported in an earlier report. The decision has now been made to close the tanks after waste retrieval with a cementitious grout to minimize infiltration and maintain the physical integrity of the tanks. This report describes testing of the residual waste with a leaching solution that simulates the composition of water passing through the grout and contacting the residual waste at the bottom of the tank.

Hanford Tank 241-C-106: Residual Waste Contaminant Release Model and Supporting Data

This report was revised in May 2007 to correct values in Section 3.4.1.7, second paragraph, last sentence; 90Sr values in Tables 3.22 and 3.32; and 99Tc values Table 4.3 and in Chapter 5. In addition, the tables in Appendix F were updated to reflect corrections to the 90Sr values. The rest of the text remains unchanged from the original report issued in May 2005. CH2M HILL is producing risk/performance assessments to support the closure of single-shell tanks at the DOEs Hanford Site. As part of this effort, staff at PNNL were asked to develop release models for contam¬inants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. This report provides the information developed by PNNL.

Thermodynamic model for uranium release from hanford site tank residual waste.

A thermodynamic model of U solid-phase solubility and paragenesis was developed for Hanford Site tank residual waste that will remain in place after tank closure. The model was developed using a combination of waste composition data, waste leach test data, and thermodynamic modeling of the leach test data. The testing and analyses were conducted using actual Hanford Site tank residual waste. Positive identification of U phases by X-ray diffraction was generally not possible either because solids in the waste were amorphous or their concentrations were not detectable by XRD for both as-received and leached residual waste. Three leachant solutions were used in the studies: deionized water, CaCO3 saturated solution, and Ca(OH)2 saturated solution. Analysis of calculated saturation indices indicate that NaUO2PO4·xH2O and Na2U2O7(am) are present in the residual wastes initially. Leaching of the residual wastes with deionized water or CaCO3 saturated solution results in preferential dissolution Na2U2O7(am) and formation of schoepite. Leaching of the residual wastes with Ca(OH)2 saturated solution appears to result in transformation of both NaUO2PO4·xH2O and Na2U2O7(am) to CaUO4. Upon the basis of these results, the paragenetic sequence of secondary phases expected to occur as leaching of residual waste progresses for two tank closure scenarios was identified.