Characterization of Direct Push Vadose Zone Sediments from the 241-U Single-Shell Tank Farm

The overall goals 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 geochemical information and data, the 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 (WMAs). 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 WMA U are found in Crumpler (2003). To meet these goals, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory (PNNL) to perform detailed analyses of vadose zone sediment collected within the U Single-Shell Tank Farm. Specifically, this report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from ten direct push characterization holes emplaced to investigate vadose zone contamination associated with potential leaks within the 241-U Single-Shell Tank Farm. Specific tanks targeted during this characterization campaign included tanks 241-U-104/241-U-105, 241-U-110, and 241-U-112. Additionally, this report compiles data from direct push samples collected north of tank 241-U-201, as well as sediment collected from the background borehole (C3393). After evaluating all the characterization and analytical data, there is no question that the vadose zone in the vicinity of tanks 241-U-104 and 241-U-105 has been contaminated by tank-related waste. This observation is not new, as gamma logging of drywells in the area has identified uranium contamination at the same depths interrogated by push hole C5602. Given that the deepest sample string analyzed from push hole C5602 contained trace activities of technetium-99, it is obvious that tank waste contamination has impacted the vadose zone to at least a depth of 92 ft bgs at this location. However, the scope of the sampling campaign was to acquire additional samples to better understand the aerial extent of contamination in the U Tank Farm; therefore, future characterization activities (i.e., a borehole) will be required to understand the total vertical depth of contamination at this location

Characterization of Direct Push Vadose Zone Sediments from the T and TY Waste Management Areas

This report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from 5 direct push characterization holes emplaced to investigate vadose zone contamination associated with leaks from tanks 241-TY-105 (UPR-200-W-152) and 241-TY-106 (UPR-200-W-153). Tank 241-TY-105 is estimated to have leaked 35,000 gal of tributyl phosphate (TBP) waste from the uranium recovery process to the vadose zone in 1960. Tank 241-TY-106 is estimated to have leaked 20,000 gal of TBP-uranium recovery waste to the vadose zone in 1959. Although several drywells in the vicinity of tank 241-TY-106 contain measurable quantities of cesium-137 and/or cobalt-60, their relatively low concentrations indicate that the contaminant inventory in the vadose zone around tank 241-TY-106 is quite small. Additionally, this report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from 7 direct push characterization holes emplaced to investigate vadose zone contamination associated with an overfill event and leak from tank 241-T-101

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

This report was revised in September 2008 to remove acid-extractable sodium data from Tables 4.7 and 4.25. 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 September 2006. 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 the Hanford Site. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory (PNNL) 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 physiochemical 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. This report also presents the interpretation of 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 below the C Tank Farm. The information presented in this report supports the WMA A-AX, C, and U field investigation report in preparation by CH2M HILL Hanford Group, Inc

Characterization of Vadose Zone Sediments from C Waste Management Area: Investigation of the C-152 Transfer Line Leak

A geologic/geochemical investigation in the vicinity of UPR-200-E-82 was performed using pairs of cone-penetrometer probe holes. A total of 41 direct-push cone-penetrometer borings (19 pairs to investigate different high moisture zones in the same sampling location and 3 individual) were advanced to characterize vadose zone moisture and the distribution of contaminants. A total of twenty sample sets, containing up to two split-spoon liners and one grab sample, were delivered to the laboratory for characterization and analysis. The samples were collected around the documented location of the C-152 pipeline leak, and created an approximately 120-ft diameter circle around the waste site. UPR-200-E-82 was a loss of approximately 2,600 gallons of Cs-137 Recovery Process feed solution containing an estimated 11,300 Ci of cesium-137 and 5 Ci of technetium-99. Several key parameters that are used to identify subsurface contamination were measured, including: water extract pH, electrical conductivity, nitrate, technetium-99, sodium, and uranium concentrations and technetium-99 and uranium concentrations in acid extracts. All of the parameters, with the exception of electrical conductivity, were elevated in at least some of the samples analyzed as part of this study. Specifically, soil pH was elevated (from 8.69 to 9.99) in five samples collected northeast and southwest of the C-152 pipeline leak. Similarly, samples collected from these same cone-pentrometer holes contained significantly more water-extractable sodium (more than 50 g/g of dry sediment), uranium (as much as 7.66E-01 g/g of dry sediment), nitrate (up to 30 g/g of dry sediment), and technetium-99 (up to 3.34 pCi/g of dry sediment). Most of the samples containing elevated concentrations of water-extractable sodium also had decreased levels of water extractable calcium and or magnesium, indicating that tank-related fluids that were high in sodium did seep into the vadose zone near these probe holes. Several of the samples containing high concentrations of water-leachable uranium also contained high pore water corrected alkalinity (3.26E+03 mg/L as CaCO3), indicating that the elevated water-leachable uranium could be an artifact of uranyl-carbonate complexation of naturally occurring labile uranium. However, a mass scan of the water extract containing the highest concentration of uranium was performed via inductively coupled mass spectrometry over the range of 230 to 240 atomic mass units, and a discernable peak was observed at mass 236. Although the data is considered qualitative, the presence of uranium-236 in the 1:1 sediment:water extract is a clear indication that the sample contains contaminant uranium [Hanford reprocessed fuel waste]. After evaluating all the characterization and analytical data, there is no question that the vadose zone surrounding the C-152 pipeline leak site has been contaminated by waste generally sent to tanks. The two zones or regions that contained the largest amount of contaminants, either in concentration or by occurrence of several key constituents/contaminants of concern, were located: 1) between the 241-C-151 and 241-C-152 Diversion Boxes (near the location of UPR-200-E-82) and 2) directly across the C-152 waste site near the C-153 Diversion Box (near where a pipeline, which connects the two diversion boxes, is shown on old blue prints . Without the use of more sophisticated analytical techniques, such as isotope signature analysis of ruthenium fission product isotopes, it is impossible to determine if the contamination observed at these two locations are from the same waste source or are a result of different leak events

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

Characterization of Direct-Push Vadose Zone Sediments from the 241-B and 241-BX Tank Farms

Geochemical tests provide evidence for the transit of a plume of caustic waste solution through the sediment column at the Hanford 241-B and -BX Tank Farms. Direct-push samples recovered from boreholes surrounding Tanks 241-B-110 and 241-BX-102 and related waste transfer lines and diversion boxes included sediments typical of those previously recovered from other localities on the Hanford Site. The Hanford formation sediments are dominantly quartzo-feldspathic sands strewn with lithic fragments, displaying a range of particle size distributions and sorting characteristics. Some moderately well-sorted, fine-grained lithologies are interpreted as lenticular bodies irregularly dispersed in coarser-grained, more poorly sorted sediments. Tier I tests conducted on the vadose zone sediments revealed an inverse correlation between moisture content and sediment size fraction (i.e., there is greater moisture content in finer-grained sediments). The Tier I tests also showed that the pore water solutions were likely sodium-rich, moderately saline, and possessed higher pH values than background (untainted) sediments. These data are characteristic of sediments that have encountered sodium-rich, saline, caustic waste solution, as documented in other reports at other suspect contamination sites around Hanford. Analyses of solutions from 1:1 water extracts reveal relatively balanced cation and anion concentrations, indicating that most of the geochemical species have been accounted for. The water extract data for affected sediments also indicate unusually high concentrations of aluminum, iron, and phosphorus. The relatively high concentrations of aluminum and iron may be the result of dissolution of secondary amorphous phases that precipitated after a reactive plume partially dissolved aluminum- and iron-bearing phases as it migrated through the sediment column. On the other hand, the presence of elevated concentrations of phosphorous may be the tell-tale signature of wastes derived from the bismuth phosphate separation process. Elements typically mobile in the geosphere, such as technetium-99, are present at either low concentrations or are below the analytical detection limit. However, we expect that the mobile elements would be present mainly along a narrow plume front, and if this front had passed deeper into the sediment profile than depths sampled, the retention of these elements would be minor. On the other hand for the direct push sediments from around BX Tank Farm, uranium-238 was detected in nearly all sediment specimens (by acid extract experiments) at concentrations above the natural crustal average (0.763 pCi/g), and we also detected the presence of several anthropogenic radioisotopes, such as cobalt-60, cesium-137, europium-154, and europium-155 (by gamma energy analysis). These data are direct confirmation of contamination of the sediments

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

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 T Tank Farm: Boreholes C4104, C4105, 299-W10-196, and RCRA Borehole 299-W11-39

This report was revised in September 2008 to remove acid-extractable sodium data from Tables 4.8, 4.28, and 4.52. 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 September 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 second 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 C4104 and C4105 in the T Tank Farm, and from borehole 299-W-11-39 installed northeast of the T Tank Farm. Finally, the measurements on sediments from borehole C4104 are compared with a nearby borehole drilled in 1993, 299- W10-196, through the tank T-106 leak plume

Characterization of Vadose Zone Sediment: Borehole 299-E33-46 Near B 110 in the B BX-BY Waste Management Area

This report was revised in September 2008 to remove acid-ectractable sodium data from Table 4.17. 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 December 2002. The overall goal of the 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 sediment from within the B-BX-BY Waste Management Area. This report is the third in a series of three 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 a borehole installed approximately 4.5 m (15 ft) northeast of tank B- 110 (borehole 299-E33-46)