The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform

R. Jeffrey Serne - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Waste Cast Stone Waste Form Qualification Testing Plan
    2012
    Co-Authors: Joseph H. Westsik, R. Jeffrey Serne
    Abstract:

    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive Waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the Wastes into high-level Waste (HLW) and low-activity Waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious Waste form, has been selected for solidification of this Secondary Waste Stream after treatment in the ETF. The Secondary-Waste Cast Stone Waste form must be acceptable for disposal in the IDF. This Secondary Waste Cast Stone Waste form qualification testing plan outlines the testing of the Waste form and immobilization process to demonstrate that the Cast Stone Waste form can comply with the disposal requirements. Specifications for the Secondary-Waste Cast Stone Waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the Waste acceptance criteria for the IDF, and the Waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing neededmore » to demonstrate that the Waste form can comply with these Waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable Waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the Waste form in the disposal environment. These Waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the Secondary-Waste Cast Stone Waste form in the IDF« less

  • Radionuclide Retention Mechanisms in Secondary Waste-Form Testing: Phase II
    2011
    Co-Authors: Michelle M. Valenta, Chul-woo Chung, Jung-seok Yang, Mark H. Engelhard, R. Jeffrey Serne, Kent E. Parker, Guohui Wang, Kirk J. Cantrell, Joseph H. Westsik
    Abstract:

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate candidate stabilization technologies that have the potential to successfully treat liquid Secondary Waste Stream effluents produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). WRPS is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF, a multi-Waste, treatment-and-storage unit that has been permitted under the Resource Conservation and Recovery Act (RCRA), can accept dangerous, low-level, and mixed Wastewaters for treatment. The STU needs to be operational by 2018 to receive Secondary liquid Waste generated during operation of the WTP. The STU will provide the additional capacity needed for ETF to process the increased volume of Secondary Waste expected to be produced by WTP. This report on radionuclide retention mechanisms describes the testing and characterization results that improve understanding of radionuclide retention mechanisms, especially for pertechnetate, {sup 99}TcO{sub 4}{sup -} in four different Waste forms: Cast Stone, DuraLith alkali aluminosilicate geopolymer, encapsulated fluidized bed steam reforming (FBSR) product, and Ceramicrete phosphate bonded ceramic. These data and results will be used to fill existing datamore » gaps on the candidate technologies to support a decision-making process that will identify a subset of the candidate Waste forms that are most promising and should undergo further performance testing.« less

  • Capture and Immobilization of Technetium from Liquid Radioactive Waste Streams into a Stable Goethite Mineral Form—11351
    2011
    Co-Authors: Joseph H. Westsik, Nikolla P. Qafoku, R. Jeffrey Serne
    Abstract:

    Technetium-99 (Tc-99), a long-lived fission product, presents a challenge in managing legacy Wastes from the production of nuclear materials. In the thermal processes used to convert radioactive tank Wastes to a glass Waste form, much of the Tc-99 volatilizes in the high temperatures of the glass melters and is collected in off-gas scrubber systems within the vitrification plants. Although the off-gas scrubber solutions containing the Tc-99 are recycled back to the melters, some Tc ultimately leaves the vitrification facilities as a Secondary Waste Stream requiring treatment and immobilization. The off-gas scrubber solutions also capture S, Cl, F, and Cr that, when recycled to the melter, reduce the Waste loading in the glass. For the Secondary Wastes, risk assessments indicate that Tc-99 is a significant contributor to the environmental impact from the disposal of these Wastes in low-activity Waste disposal facilities. There are, therefore, incentives to reduce the impacts of Tc-99 within the vitrification and Waste disposal facilities. Goethite is a stable iron oxyhydroxide mineral, FeOOH, that is showing the potential to effectively sequester Tc from radioactive Waste liquids. Testing to date has shown that Tc-99 can be removed from an aqueous simulant of a caustic off-gas scrubber solution by a process that reduces Tc-99 from Tc(VII) to Tc(IV) and co-precipitates the Tc(IV) with iron to form a goethite-dominant iron oxy-hydroxide material [(Tc,Fe)OOH]. The process involves reducing the pertechnetate, Tc(VII), to Tc(IV) with the reductant Fe(II); the Tc(IV) then co-precipitates with the iron to form the goethite. Goethite appears to be effective in sequestering Tc because the Tc(IV) and Fe(III) are similar in cation size, metal-oxygen bond lengths, and number of coordinating oxygen atoms. In tests with both deionized water and a caustic offgas scrubber simulant solution containing Tc(VII), between 93 and 99 percent of the Tc was removed from the liquids and captured in the goethite. X-ray diffraction and transmission electron microscopy confirm goethite as the primary product with some magnetite also present. X-ray absorption spectroscopy (XAS) confirmed that the Tc was in the +4 oxidation state and that the bond distances were consistent with substitution of Tc(IV) for Fe(III) in the goethite mineral structure. The final Tc-goethite product was also tested for Tc leachability in various leachants for up to 180 days. Further, XAS showed no reoxidation of Tc(IV) to Tc(VII) in the leaching solutions nor the dried Tc-goethite solid exposed to air, even after 180 days of leaching or air exposure. There was minimal dissolution of the goethite and subsequent release of Tc at the expected conditions (pH=7.2) of pore waters in the Hanford Integrated Disposal Facility. Testing is currently underway to demonstrate the capture of Tc in goethite from more complex Waste solutions. Rhenium is also being evaluated as a surrogate for Tc in the goethite process, leading to a bench-scale demonstration of the preparation of Re- and/or Tc- goethite.

Joseph H. Westsik - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Waste Cast Stone Waste Form Qualification Testing Plan
    2012
    Co-Authors: Joseph H. Westsik, R. Jeffrey Serne
    Abstract:

    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive Waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the Wastes into high-level Waste (HLW) and low-activity Waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious Waste form, has been selected for solidification of this Secondary Waste Stream after treatment in the ETF. The Secondary-Waste Cast Stone Waste form must be acceptable for disposal in the IDF. This Secondary Waste Cast Stone Waste form qualification testing plan outlines the testing of the Waste form and immobilization process to demonstrate that the Cast Stone Waste form can comply with the disposal requirements. Specifications for the Secondary-Waste Cast Stone Waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the Waste acceptance criteria for the IDF, and the Waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing neededmore » to demonstrate that the Waste form can comply with these Waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable Waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the Waste form in the disposal environment. These Waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the Secondary-Waste Cast Stone Waste form in the IDF« less

  • Radionuclide Retention Mechanisms in Secondary Waste-Form Testing: Phase II
    2011
    Co-Authors: Michelle M. Valenta, Chul-woo Chung, Jung-seok Yang, Mark H. Engelhard, R. Jeffrey Serne, Kent E. Parker, Guohui Wang, Kirk J. Cantrell, Joseph H. Westsik
    Abstract:

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate candidate stabilization technologies that have the potential to successfully treat liquid Secondary Waste Stream effluents produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). WRPS is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF, a multi-Waste, treatment-and-storage unit that has been permitted under the Resource Conservation and Recovery Act (RCRA), can accept dangerous, low-level, and mixed Wastewaters for treatment. The STU needs to be operational by 2018 to receive Secondary liquid Waste generated during operation of the WTP. The STU will provide the additional capacity needed for ETF to process the increased volume of Secondary Waste expected to be produced by WTP. This report on radionuclide retention mechanisms describes the testing and characterization results that improve understanding of radionuclide retention mechanisms, especially for pertechnetate, {sup 99}TcO{sub 4}{sup -} in four different Waste forms: Cast Stone, DuraLith alkali aluminosilicate geopolymer, encapsulated fluidized bed steam reforming (FBSR) product, and Ceramicrete phosphate bonded ceramic. These data and results will be used to fill existing datamore » gaps on the candidate technologies to support a decision-making process that will identify a subset of the candidate Waste forms that are most promising and should undergo further performance testing.« less

  • Capture and Immobilization of Technetium from Liquid Radioactive Waste Streams into a Stable Goethite Mineral Form—11351
    2011
    Co-Authors: Joseph H. Westsik, Nikolla P. Qafoku, R. Jeffrey Serne
    Abstract:

    Technetium-99 (Tc-99), a long-lived fission product, presents a challenge in managing legacy Wastes from the production of nuclear materials. In the thermal processes used to convert radioactive tank Wastes to a glass Waste form, much of the Tc-99 volatilizes in the high temperatures of the glass melters and is collected in off-gas scrubber systems within the vitrification plants. Although the off-gas scrubber solutions containing the Tc-99 are recycled back to the melters, some Tc ultimately leaves the vitrification facilities as a Secondary Waste Stream requiring treatment and immobilization. The off-gas scrubber solutions also capture S, Cl, F, and Cr that, when recycled to the melter, reduce the Waste loading in the glass. For the Secondary Wastes, risk assessments indicate that Tc-99 is a significant contributor to the environmental impact from the disposal of these Wastes in low-activity Waste disposal facilities. There are, therefore, incentives to reduce the impacts of Tc-99 within the vitrification and Waste disposal facilities. Goethite is a stable iron oxyhydroxide mineral, FeOOH, that is showing the potential to effectively sequester Tc from radioactive Waste liquids. Testing to date has shown that Tc-99 can be removed from an aqueous simulant of a caustic off-gas scrubber solution by a process that reduces Tc-99 from Tc(VII) to Tc(IV) and co-precipitates the Tc(IV) with iron to form a goethite-dominant iron oxy-hydroxide material [(Tc,Fe)OOH]. The process involves reducing the pertechnetate, Tc(VII), to Tc(IV) with the reductant Fe(II); the Tc(IV) then co-precipitates with the iron to form the goethite. Goethite appears to be effective in sequestering Tc because the Tc(IV) and Fe(III) are similar in cation size, metal-oxygen bond lengths, and number of coordinating oxygen atoms. In tests with both deionized water and a caustic offgas scrubber simulant solution containing Tc(VII), between 93 and 99 percent of the Tc was removed from the liquids and captured in the goethite. X-ray diffraction and transmission electron microscopy confirm goethite as the primary product with some magnetite also present. X-ray absorption spectroscopy (XAS) confirmed that the Tc was in the +4 oxidation state and that the bond distances were consistent with substitution of Tc(IV) for Fe(III) in the goethite mineral structure. The final Tc-goethite product was also tested for Tc leachability in various leachants for up to 180 days. Further, XAS showed no reoxidation of Tc(IV) to Tc(VII) in the leaching solutions nor the dried Tc-goethite solid exposed to air, even after 180 days of leaching or air exposure. There was minimal dissolution of the goethite and subsequent release of Tc at the expected conditions (pH=7.2) of pore waters in the Hanford Integrated Disposal Facility. Testing is currently underway to demonstrate the capture of Tc in goethite from more complex Waste solutions. Rhenium is also being evaluated as a surrogate for Tc in the goethite process, leading to a bench-scale demonstration of the preparation of Re- and/or Tc- goethite.

Serne R. Jeffrey - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Waste Cast Stone Waste Form Qualification Testing Plan
    Pacific Northwest National Laboratory (U.S.), 2012
    Co-Authors: Westsik, Joseph H., Serne R. Jeffrey
    Abstract:

    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive Waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the Wastes into high-level Waste (HLW) and low-activity Waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious Waste form, has been selected for solidification of this Secondary Waste Stream after treatment in the ETF. The Secondary-Waste Cast Stone Waste form must be acceptable for disposal in the IDF. This Secondary Waste Cast Stone Waste form qualification testing plan outlines the testing of the Waste form and immobilization process to demonstrate that the Cast Stone Waste form can comply with the disposal requirements. Specifications for the Secondary-Waste Cast Stone Waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the Waste acceptance criteria for the IDF, and the Waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing needed to demonstrate that the Waste form can comply with these Waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable Waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the Waste form in the disposal environment. These Waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the Secondary-Waste Cast Stone Waste form in the ID

  • Review of Potential Candidate Stabilization Technologies for Liquid and Solid Secondary Waste Streams
    Pacific Northwest National Laboratory (U.S.), 2010
    Co-Authors: Pierce, Eric M., Mattigod Shas, Westsik, Joseph H., Serne R. Jeffrey, Icenhower, Jonathan P., Scheele, Randall D., Um Wooyong, Qafoku Nikolla
    Abstract:

    Pacific Northwest National Laboratory has initiated a Waste form testing program to support the long-term durability evaluation of a Waste form for Secondary Wastes generated from the treatment and immobilization of Hanford radioactive tank Wastes. The purpose of the work discussed in this report is to identify candidate stabilization technologies and getters that have the potential to successfully treat the Secondary Waste Stream liquid effluent, mainly from off-gas scrubbers and spent solids, produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Down-selection to the most promising stabilization processes/Waste forms is needed to support the design of a solidification treatment unit (STU) to be added to the Effluent Treatment Facility (ETF). To support key decision processes, an initial screening of the Secondary liquid Waste forms must be completed by February 2010

Westsik, Joseph H. - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Waste Cast Stone Waste Form Qualification Testing Plan
    Pacific Northwest National Laboratory (U.S.), 2012
    Co-Authors: Westsik, Joseph H., Serne R. Jeffrey
    Abstract:

    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive Waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the Wastes into high-level Waste (HLW) and low-activity Waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious Waste form, has been selected for solidification of this Secondary Waste Stream after treatment in the ETF. The Secondary-Waste Cast Stone Waste form must be acceptable for disposal in the IDF. This Secondary Waste Cast Stone Waste form qualification testing plan outlines the testing of the Waste form and immobilization process to demonstrate that the Cast Stone Waste form can comply with the disposal requirements. Specifications for the Secondary-Waste Cast Stone Waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the Waste acceptance criteria for the IDF, and the Waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing needed to demonstrate that the Waste form can comply with these Waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable Waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the Waste form in the disposal environment. These Waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the Secondary-Waste Cast Stone Waste form in the ID

  • Review of Potential Candidate Stabilization Technologies for Liquid and Solid Secondary Waste Streams
    Pacific Northwest National Laboratory (U.S.), 2010
    Co-Authors: Pierce, Eric M., Mattigod Shas, Westsik, Joseph H., Serne R. Jeffrey, Icenhower, Jonathan P., Scheele, Randall D., Um Wooyong, Qafoku Nikolla
    Abstract:

    Pacific Northwest National Laboratory has initiated a Waste form testing program to support the long-term durability evaluation of a Waste form for Secondary Wastes generated from the treatment and immobilization of Hanford radioactive tank Wastes. The purpose of the work discussed in this report is to identify candidate stabilization technologies and getters that have the potential to successfully treat the Secondary Waste Stream liquid effluent, mainly from off-gas scrubbers and spent solids, produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Down-selection to the most promising stabilization processes/Waste forms is needed to support the design of a solidification treatment unit (STU) to be added to the Effluent Treatment Facility (ETF). To support key decision processes, an initial screening of the Secondary liquid Waste forms must be completed by February 2010

Charles L. Crawford - One of the best experts on this subject based on the ideXlab platform.

  • Radioactive Benchscale Steam Reformer Demonstration of a Monolithic Steam Reformed Mineralized Waste Form for Hanford Waste Treatment Plant Secondary Waste - 12306
    2012
    Co-Authors: Brent Evans, Arlin Olson, J. Bradley Mason, Kevin Ryan, Carol M. Jantzen, Charles L. Crawford
    Abstract:

    Hanford currently has 212,000 m 3 (56 million gallons) of highly radioactive mixed Waste stored in the Hanford tank farm. This Waste will be processed to produce both high-level and low-level activity fractions, both of which are to be vitrified. Supplemental treatment options have been under evaluation for treating portions of the low-activity Waste, as well as the liquid Secondary Waste from the low-activity Waste vitrification process. One technology under consideration has been the THOR ® fluidized bed steam reforming process offered by THOR Treatment Technologies, LLC (TTT). As a follow-on effort to TTT’s 2008 pilot plant FBSR non-radioactive demonstration for treating low-activity Waste and Waste treatment plant Secondary Waste, TTT, in conjunction with Savannah River National Laboratory, has completed a bench scale evaluation of this same technology on a chemically adjusted radioactive surrogate of Hanford’s Waste treatment plant Secondary Waste Stream. This test generated a granular product that was subsequently formed into monoliths, using a geopolymer as the binding agent, that were subjected to compressibility testing, the Product Consistency Test and other leachability tests, and chemical composition analyses. This testing has demonstrated that the mineralized Waste form, produced by co-processing Waste with kaolin clay using the TTT process, is as durable as low-activity Waste glass [1]. Testing has shown the resulting monolith Waste form is durable, leach resistant, and chemically stable, and has the added benefit of capturing and retaining the majority of Tc-99, I-129, and other target species at high levels.