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in creator/contributor: "KRUMHANSL, JAMES L."  
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Occurrence, Characterization and Synthesis of Hanford and SRS Tank Heel Materials

Description: The long-range objective of this study was to develop chemically assisted technologies for removing heels from tanks. In FY 01, the first two steps toward this objective were taken: (1) catalogue the occurrence and nature of tank heels and assess which materials are available for study and (2) develop methods for synthesizing non-radioactive surrogate heel materials for use in testing potential removal technologies. The chief finding of Task 1 was the existence of ''heels'', depending on the de… more
Date: July 1, 2002
Creator: KRUMHANSL, JAMES L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Phase Chemistry of Tank Sludge Residual Components

Description: About four or five distinct reprocessing technologies were used at various times in Hanford's history. After removing U and Pu (or later 137Cs and 90Sr), the strongly acidic HLW was ''neutralized'' to high pH (>13) and stored in steel-lined tanks. High pH was necessary to prevent tank corrosion. While each technology produced chemically distinct waste, all wastes were similar in that they were high pH, concentrated, aqueous solutions. Dominant dissolved metals were Fe and/or Al, usually foll… more
Date: June 1, 2000
Creator: Krumhansl, James L. & Nagy, Kathryn L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Phase Chemistry of Tank Sludge Residual Components

Description: We are attempting to understand the solid phase chemistry of the high level nuclear waste (HLW) stored in tanks at Hanford. Because this waste is compositionally complex, our approach is to study experimentally the aging dynamics of simplified systems whose bulk chemistry approximates that of the tank sludges. After a basic understanding of these dynamics has been attained we plan to increase the compositional complexities one component at a time, in order to assess the influence of each compon… more
Date: November 29, 1999
Creator: Krumhansl, James L.; Liu, Jun; Nagy, Kathryn L. & Brady, Patrick V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Comprehensive Study of the Solubility, Thermochemistry, Ion Exchange, and Precipitation Kinetics of NO3 Cancrinite and NO3 Sodalite

Description: NO3 cancrinite and NO3 sodalite haves been found as a common sodium alumino-silicate forming in strongly caustic alkaline aqueous solutions associated with radioactive High Level Waste (HLW) stored in many underground tanks and also in nuclear waste treatment facilities such as the Savannah River Site (SRS). The precipitation of alumino-silicate phases from caustic nuclear wastes has proven to be problematic in a number of processes in waste treatment facilities including radionuclide separatio… more
Date: June 1, 2003
Creator: Colon, Carlos F. Joyce; Navrotsky, Alexandra; Krumhansl, James L. & Nyman, May
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Comprehensive Study of the Solubility, Thermochemistry, Ion Exchange, and Precipitation Kinetics of NO3 Cancrinite and NO3 Sodalite

Description: NO3 cancrinite and NO3 sodalite haves been found as a common sodium alumino-silicate forming in strongly caustic alkaline aqueous solutions associated with radioactive High Level Waste (HLW) stored in many underground tanks and also in nuclear waste treatment facilities such as the Savannah River Site (SRS). The appearance of these phases have created very expensive problems in waste treatment plants by fouling process evaporators in the SRS waste processing facility. Therefore, in order to pre… more
Date: June 1, 2002
Creator: Colon, Carlos F. Jove; Navrotsky, Alexandra; Krumhansl, James L. & Nyman, May
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Phase Chemistry of Tank Sludge Residual Components

Description: Experiments began with ''neutralization'' of iron (III)-aluminum nitrate solutions by addition of sodium hydroxide at room temperature. The final pH of most experiments was approximately 13.7. The samples were neutralized in PP or HDPE bottles that were then submerged in a water bath and aged at 90 C for up to 120 h. (In the low-Al systems, X-ray diffraction (XRD) results suggest that transformation of the initial amorphous precipitate to crystalline phases was complete after this time.) Experi… more
Date: June 1999
Creator: Krumhansl, James L.; Liu, Jun; Nagy, Kathryn L. & Brady, Patrick V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Corrosion of Uranium in Desert Soil, with Application to GCD Source Term M

Description: Uranium fragments from the Sandia Sled Track were studied as analogues for weapons components and depleted uranium buried at the Greater Confinement Disposal (GCD) site in Nevada. The Sled Track uranium fragments originated as weapons mockups and counterweights impacted on concrete and soil barriers, and experienced heating and fragmentation similar to processes thought to affect the Nuclear Weapons Accident Residues (NWAR) at GCD. Furthermore, the Sandia uranium was buried in unsaturated deser… more
Date: September 1, 1999
Creator: ANDERSON, HOWARD L.; BACA, JULIANNE; KRUMHANSL, JAMES L.; STOCKMAN, HARLAN W. & THOMPSON, MOLLIE E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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 p… more
Date: May 19, 2000
Creator: Krumhansl, James L.; Zhang, Pengchu; Westrich, Henry R.; Bryan, Charles R. & Molecke, Martin A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Chemical evolution of leaked high-level liquid wastes in Hanford soils

Description: A number of Hanford tanks have leaked high level radioactive wastes (HLW) into the surrounding unconsolidated sediments. The disequilibrium between atmospheric C0{sub 2} or silica-rich soils and the highly caustic (pH > 13) fluids is a driving force for numerous reactions. Hazardous dissolved components such as {sup 133}Cs, {sup 79}Se, {sup 99}Tc may be adsorbed or sequestered by alteration phases, or released in the vadose zone for further transport by surface water. Additionally, it is lik… more
Date: May 19, 2000
Creator: Nyman, May D.; Krumhansl, James L.; Zhang, Pengchu; Anderson, Howard L. & Nenoff, Tina M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Comprehensive Study of the Solubility, Thermochemistry, Ion Exchange, and Precipitation Kinetics of NO3 Cancrinite and NO3 Sodalite (Project No.: 81959)

Description: NO3 cancrinite and NO3 sodalite haves been found as a common sodium alumino-silicate forming in strongly caustic and alkaline aqueous solutions associated with radioactive High Level Waste (HLW) stored in many underground tanks and also in nuclear waste treatment facilities such as the Savannah River Site (SRS). The appearance of these phases have created very expensive problems in waste treatment plants by fouling process evaporators in the SRS waste processing facility. Therefore, in order to… more
Date: June 1, 2004
Creator: Colon, Carlos F. Jove; Navrotsky, Alexandra; Krumhansl, James L.; Nyman, May & Liu, Qingyuan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Phase chemistry of tank sludge residual components. 1998 annual progress report

Description: 'The proposed research will provide a scientific basis for predicting the long-term fate of radionuclides remaining with the sludge in decommissioned waste tanks. Nuclear activities in the United States and elsewhere produce substantial volumes of highly radioactive semi-liquid slurries that traditionally are stored in large underground tanks while final waste disposal strategies are established. Although most of this waste will eventually be reprocessed a contaminated structure will remain whi… more
Date: June 1, 1998
Creator: Krumhansl, James L.; Brady, P. V.; Liu, Jun & Nagy, Kathryn L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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{sup 129}I{sup -} and {sup 99}TcO{sub 4}-scavengers for low level radioactive waste backfills

Description: Minimization of {sup 129}I{sup -} and {sup 99}TcO{sub 4}{sup -} transport to the biosphere is critical to the success of low level radioactive waste (LLRW) storage facilities. Here we experimentally identify and classify optimal sorbent materials for inclusion in LLRW backfills. For low pH conditions (pH 4-5), Cu-sulfides and possibly imogolite-rich soils provide K{sub d}`s (surface-solution partition coefficients) of roughly 10{sup 3} ml g{sup -1} for iodide, and 10{sup 2} ml g{sup -1} for tec… more
Date: March 1, 1997
Creator: Balsley, Steven D.; Brady, Patrick V.; Krumhansl, James L. & Anderson, Howard L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Phase chemistry and radionuclide retention from simulated tank sludges

Description: Decommissioning high level nuclear waste tanks will leave small amounts of residual sludge clinging to the walls and floor of the structures. The permissible amount of material left in the tanks depends on the radionuclide release characteristics of the sludge. At present, no systematic process exists for assessing how much of the remaining inventory will migrate, and which radioisotopes will remain relatively fixed. Working with actual sludges is both dangerous and prohibitively expensive. Con… more
Date: May 19, 2000
Creator: Krumhansl, James L.; Liu, J.; Arthur, Sara E.; Hutcherson, Sheila K.; Qian, Morris & Anderson, Howard L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Status of Research on Magnesium Oxide Backfill

Description: For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as… more
Date: July 31, 2000
Creator: Papenguth, Hans W.; Krumhansl, James L.; Bynum, R. Vann; Wang, Yifeng; Kelly, John W.; Anderson, Howard et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A process model of natural attenuation in drainage from a historic mining district

Description: A process model was used to better understand the controls on the chemical evolution of drainage in a historic mining district. At the Pecos Mine Operable Unit, New Mexico, drainage near the waste rock pile is acidic (pH varies from 3.0--5.0) and carries high concentrations of Zn, Al, Cu and Pb. As drainage flows toward the Pecos River, pH increases to greater than 7 and heavy metal content decreases. A process model of natural attenuation in this drainage shows the main controls on pH are reac… more
Date: June 5, 2000
Creator: BERGER,AMY C.; BETHKE,CRAIG M. & KRUMHANSL,JAMES L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reactive barriers for {sup 137}Cs retention

Description: {sup 137}Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of {sup 137}Cs from soils and groundwaters is exceedingly difficult. Because the half life of {sup 137}Cs is only 30.2 years, remediation might be more effective (and less costly) if {sup 137}Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings whe… more
Date: May 19, 2000
Creator: KRUMHANSL,JAMES L.; BRADY,PATRICK V. & ANDERSON,HOWARD L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A historical review of Waste Isolation Pilot Plant backfill development

Description: Backfills have been part of Sandia National Laboratories' [Sandia's] Waste Isolation Pilot Plant [WIPP] designs for over twenty years. Historically, backfill research at Sandia has depended heavily on the changing mission of the WIPP facility. Early testing considered heat producing, high level, wastes. Bentonite/sand/salt mixtures were evaluated and studies focused on developing materials that would retard brine ingress, sorb radionuclides, and withstand elevated temperatures. The present-day … more
Date: June 5, 2000
Creator: KRUMHANSL,JAMES L.; MOLECKE,MARTIN A.; PAPENGUTH,HANS W. & BRUSH,LAURENCE H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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