216-U-10 Pond and 216-Z-19 Ditch characterization studies

Duncan, David; Graham, M.J.; Hall, '; Hall, V.W.; Landeen, D.S.; Leitz, J.G.; Mitchell, Roger

doi:10.2172/10156239

Cited by 9 publications

(11 citation statements)

References 16 publications

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“…Because of the fine-grained nature of mud, silt was the dominant particle size in the B19377 sample. The other samples are typical gravel-and sand-dominated Ringold Unit E formation, consistent with other geologic characterizations previously published (see Bjornstad 1984Bjornstad , 1990Bjornstad et al 2001Bjornstad et al , 2002Brown 1959;Connelly et al 1992;Delaney et al1991;Fecht and Weekes 1996;Last 1994;Lindsey 1995Lindsey , 1996Lindsey et al 1992aLindsey et al , 1992bLindsey et al , 1994Myers and Price 1979;Reidel et al 1992;Slate 2000;Tallman et al 1979Tallman et al , 1981Williams et al 2002;and Wood et al 2001). …”

Section: Particle Size Distributionsupporting

confidence: 84%

Characterization of 200-UP-1 Aquifer Sediments and Results of Sorption-Desorption Tests Using Spiked Uncontaminated Groundwater

Um¹,

Serne²,

Bjornstad³

et al. 2005

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Se-79, and Np-237 during FY 2005. The study completed and summarized in this report will help determine the current risk of the groundwater plume and aid in choosing remediation alternatives for the COC in 200-UP-1 subsurface environments should remediation be necessary.Sediment characterization showed only 4 out of 13 core liner samples were intact, and the others were slough material that dropped to the bottom of the borehole before the split-spoon sampling. The intact samples showed typical Ringold Unit E characteristics such as being dominated by gravel and sand. Moderately reducing conditions are inferred in some core from borehole C4299. This reducing condition was likely caused by the hard tool process used to drill the wells. One core liner from C4299 (B19140) showed significant presence of ferric iron oxide/clay coatings on the gravel surfaces. The 200-UP-1 sediments do contain some clay minerals that exhibit significant cation exchange capacity and thus should be good adsorbents of cationic contaminants. This is especially true of the Ringold Lower mud sample, B19377, from borehole C4300. No highly contaminated sediments-including uranium-were found in the cores from the three new boreholes in the 200-UP-1 operable unit. The presence of slough and "flour" caused by hard tooling is a serious challenge to obtaining field-representative sediments for use in geochemical experiments to determine the adsorption-desorption tendencies of redox sensitive elements such as uranium.The adsorption of COC on intact Ringold Formation sediments and Fe/clay coatings showed that most of the anionic contaminants [Tc(VII), Se(VI), U(VI), Cr(VI), and I(-I)] did not adsorb well compared to cationic [Np(V), Sr(II), and Cs(I)] radionuclides. The high hydrous iron oxide content in Fe oxide/clay coatings caused the highest K d values for U and Np, suggesting that these hydrous iron oxides are the key solid adsorbent in the sediments that control the fate of U and Np. Enhanced adsorption behavior for Tc and Cr, and perhaps Se, on the composite B19136 and B19137 sediment was considered an "artifact" caused by the induced reducing conditions from the hard tool drilling.Additional U(VI) adsorption K d studies were performed on Ringold Formation sediments subjected to varying solution geochemical conditions such as varying the dissolved U and total bicarbonate/carbonate concentration in the groundwater to develop a more robust data base of U(VI) K d s. The <2 mm size fraction of three 200-UP-1 sediments showed a linear U (VI) adsorption isotherm up to 1 ppm of total U (VI) concentration in solution. This fact validates the use of a linear adsorption isotherm (K d ) to predict U (VI) adsorption for sediments in the 200-UP-1 groundwater plume. However, this is not the same as stating that the U (VI) K d value will be constant if the groundwater chemical composition at 200-UP-1 changes with space or time.iv The additional U (VI) K d s obtained from varying carbonate concentrations in solution indicated that U (VI) adsorption was stro...

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Section: Particle Size Distributionsupporting

confidence: 84%

Characterization of 200-UP-1 Aquifer Sediments and Results of Sorption-Desorption Tests Using Spiked Uncontaminated Groundwater

Um¹,

Serne²,

Bjornstad³

et al. 2005

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“…Figure 5.2 shows the liquid discharge history for the two ponds. The 216-T pond system is estimated to have received approximately 424 billion liters of effluent (Alexander et al 1995); the 216-U pond received about 158 billion liters of effluent (Last 1994). The large-volume disposals to the ponds (and, lesser volumes to cribs and ditches) artificially recharged the uppermost unconfined aquifer, creating large water-table mounds.…”

Section: Aquifer Propertiesmentioning

confidence: 99%

Characterization of Vadose Zone Sediments Below the T Tank Farm: Boreholes C4104, C4105, 299-W10-196 and RCRA Borehole 299-W11-39

Serne¹,

Bjornstad²,

Horton³

et al. 2004

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Executive SummaryThis 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.Sediments from borehole 299-W-11-39 were considered to be background uncontaminated sediments against which to compare contaminated sediments for the T tank farm characterization effort. However, during characterization of the sediments from 299-W11-39, numerous indications were found that suggest some nearsurface contamination may have occurred in the past such that the water extract information for sediments from 299-W11-39 may not represent natural background conditions. Therefore, most of the comparisons of the contaminated T tank farm boreholes to natural background conditions used the sediment characterization information from background borehole 299-W10-27, just northeast of the TX Tank Farm.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 T Tank Farm. The information presented in this report supports the T-TX-TY Waste Management Area field investigation report (a) in preparation by CH2M HILL Hanford Group, Inc. Sediment samples from the boreholes 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, radionuclide 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). Key radiocontaminants, technetium-99, actinides, fission products (including strontium-90, europium radioisotopes, ruthenium and molybdenum), cobalt-60, and uranium, along with other trace metals were determined in acid and water...

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“…More than 90% of the plutonium inventory discharged to the U Pond disposal system was retained in these ditches. Plutonium-239 and americium-241 concentrations as high as 33,000 pCi/g and 8,200,000 pCi/g, respectively, were measured in sediment samples collected from the 216-Z-19 Ditch (in March and April 1976) (Last et al 1994). Concentrations measured in surface samples collected from the U Pond delta in November 1978 were as high as 119,000 pCi/g (plutonium-239) and 8,300 pCi/g (americium-241) (Last et al 1994).…”

Section: Waste Site 216-u-10mentioning

confidence: 99%

“…Plutonium-239 and americium-241 concentrations as high as 33,000 pCi/g and 8,200,000 pCi/g, respectively, were measured in sediment samples collected from the 216-Z-19 Ditch (in March and April 1976) (Last et al 1994). Concentrations measured in surface samples collected from the U Pond delta in November 1978 were as high as 119,000 pCi/g (plutonium-239) and 8,300 pCi/g (americium-241) (Last et al 1994). The highest concentrations of plutonium-239/240 and americium-241 measured in U Pond bottom sediments (in 1974) were 370 pCi/g and 320 pCi/g, respectively (Last et al 1994).…”

Section: Waste Site 216-u-10mentioning

confidence: 99%

“…The site operated during the period 1944-1995. The 216-U-10 (U Pond) and its associated 216-Z-19 Ditch have fission products and uranium distributed throughout most of the disposal system while transuranics (plutonium and americium) are localized more closely to the points of discharge (Last et al 1994). The 216-Z-19 Ditch and its backfilled predecessors, the 216-Z-11 and 216-Z-1 ditches, received discharges containing plutonium-239/240, plutonium-238, and americium-241.…”

Section: Waste Site 216-u-10mentioning

confidence: 99%

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Transuranic Contamination in Sediment and Groundwater at the U.S. DOE Hanford Site

Cantrell¹

2009

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SummaryThis document presents a review of transuranic radionuclide contamination in sediments and groundwater at the U.S. Department of Energy (DOE) Hanford Site. The review focuses primarily on plutonium-239/240 and americium-241; however, other transuranic nuclides are discussed as well, including neptunium-237, plutonium-238, and plutonium-241. The scope of the review includes liquid process wastes intentionally disposed to constructed waste disposal facilities such as trenches, cribs, and burial grounds, as well as unplanned releases to the ground surface. The review does not include liquid wastes disposed to tanks or solid wastes disposed to burial grounds.It is estimated that more than 11,800 Ci of plutonium-239; 28,700 Ci of americium-241; and 55 Ci of neptunium-237 have been disposed as liquid waste to the near surface environment at the Hanford Site. Despite the very large quantities of transuranic contaminants disposed to the vadose zone at the site, only minuscule amounts have entered the groundwater. Currently, no wells onsite exceed the DOE-derived concentration guide for plutonium-239/240 (30 pCi/L) or any other transuranic contaminant in filtered samples. The DOE-derived concentration guide was exceeded by a small fraction in unfiltered samples from one well ( The primary reason that disposal of these large quantities of transuranic radionuclides directly to the vadose zone at the Hanford Site has not resulted in widespread groundwater contamination is that under the typical oxidizing and neutral to slightly alkaline pH conditions of the Hanford vadose zone, transuranic radionuclides (plutonium and americium in particular) have a very low solubility and high affinity for surface adsorption to mineral surfaces common within the Hanford vadose zone. In addition, the vadose zone is typically very thick (hundreds of feet), and the net infiltration rate is very low due to the desert climate.In some cases in which transuranic radionuclides have been co-disposed with acidic liquid waste, transport through the vadose zone for considerable distances has occurred. For example, at the 216-Z-9 Trench, plutonium-239 and americium-241 have moved to depths in excess of 36 m (118 ft) below ground surface. Acidic conditions and the presence of possible complexants could increase the solubility of these contaminants and reduce adsorption to mineral surfaces. Subsequent neutralization of the acidity by naturally occurring calcite in the vadose zone (particularly in the Cold Creek unit) appears to have effectively stopped further migration. iv Characterization studies for most of the sites reviewed in the document are generally limited. The most prevalent characterization methods used centered around geophysical logging. Characterization of a number of sites included laboratory analysis of borehole sediment samples specifically for radionuclides and other contaminants, as well as for geologic and hydrologic properties. In some instances, more detailed research-level studies were conducted.The 216-Z-9 Trench is a case...

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216-U-10 Pond and 216-Z-19 Ditch characterization studies

Cited by 9 publications

References 16 publications

Characterization of 200-UP-1 Aquifer Sediments and Results of Sorption-Desorption Tests Using Spiked Uncontaminated Groundwater

Characterization of 200-UP-1 Aquifer Sediments and Results of Sorption-Desorption Tests Using Spiked Uncontaminated Groundwater

Characterization of Vadose Zone Sediments Below the T Tank Farm: Boreholes C4104, C4105, 299-W10-196 and RCRA Borehole 299-W11-39

Transuranic Contamination in Sediment and Groundwater at the U.S. DOE Hanford Site

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