Influence of bentonite and zeolite in cementation of dry radioactive evaporator concentrates

Plećaš, I.; Dimović, Slavko; Smiciklas, I.

doi:10.1016/j.clay.2008.07.003

Cited by 15 publications

(7 citation statements)

References 13 publications

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“…The activity of HLW is mainly determined by the isotopes of cesium ( 134 Cs, 137 Cs), which is an alkali metal and, therefore, the most leached from the matrix materials. It is known that to reduce the leaching of Cs isotopes from matrices, radionuclides are converted to insoluble compounds (for example, as part of nickel–cesium ferrocyanide [12]) or exposed by sorption on specially selected sorbents (based on clinoptilolite [15,16,17,18] and clay minerals [19,20]). Inorganic sorbents based on transition metal ferrocyanides are unstable in alkaline media at pH 10 [1] and elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%

“…Zeolites are the preferred inorganic ion exchange materials for radionuclide (especially cesium) concentrations from liquid RW, because of their radiation stability, high selectivity, and cation exchange capacity [22,23]. They can be incorporated into matrices (for example, cement [19,24] and glass [25,26]) ensuring a higher degree of radionuclide retention [1]. However, in the literature, there are no data on the effectiveness of the zeolite in the MKP compound in the HLW immobilization.…”

Section: Introductionmentioning

confidence: 99%

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The Influence of Zeolite (Sokyrnytsya Deposit) on the Physical and Chemical Resistance of a Magnesium Potassium Phosphate Compound for the Immobilization of High-Level Waste

Kulikova

Винокуров

2019

Molecules

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The manuscript presents the results of the development of new material for high-level waste (HLW) management: the magnesium potassium phosphate (MKP) compound. The possibility of using zeolite (Sokyrnytsya deposit) to increase the mechanical, thermal, and hydrolytic resistance of this compound with immobilized HLW was studied. The main component of the used natural zeolite is a mineral of the clinoptilolite–heulandite series, and quartz, microcline, and clay minerals (illite, sepiolite, and smectite) are present as impurities. The compressive strength of the compound, containing at least 4.2 wt % zeolite, is about 25 MPa. Compound containing 28.6 wt % zeolite retains high compressive strength (at least 9.0 MPa), even after heat treatment at 450 °C. The adding of zeolite to the composition of the compound increases its hydrolytic stability, while the leaching rate of the mobile nuclides 137Cs and 90Sr decreases up to one order of values. Differential leaching rate of radionuclides from the compound containing 28.6 wt % zeolite is 2.6 × 10−7 for 137Cs, 2.9 × 10−6 for 90Sr, 1.7 × 10−9 for 239Pu, and 2.9 × 10−9 g/(cm2∙day) for 241Am. Thus, the properties of the resulting compound correspond to the requirements for solidified HLW in Russia.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Influence of Zeolite (Sokyrnytsya Deposit) on the Physical and Chemical Resistance of a Magnesium Potassium Phosphate Compound for the Immobilization of High-Level Waste

Kulikova

Винокуров

2019

Molecules

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“…Partial replacement of cement by silica fume needed higher water/ cement ratio to keep good workability (Chuang and Wang, 1996), while the compressive strength decreased when a high proportion of ordinary Portland cement was replaced with zeolite or fly ash (El-Kamash et al, 2006;Katz et al, 2001). Thus, composite admixtures consisting of two or more kinds of mineral admixtures have emerged as a superior choice over single admixture to improve the performances of waste forms (Atkins and Glasser, 1992;Gan et al, 2005;Pan et al, 2001;Plecas et al, 2009). The blending amount of admixtures was crucial for performances of waste forms and the optimal amount varied in different formulas.…”

Section: Introductionmentioning

confidence: 96%

“…Extensive substitution and solid-solution in the ettringite crystal structure enable SAC to have high affinities for radioactive nuclides. Based on cement hydration, many cementation formulas for radioactive wastes have been developed by adding mineral admixtures such as zeolite, blast-furnace slag, silica fume and fly ash (Asavapisit et al, 2001;El-Kamash et al, 2006;Katz et al, 2001;Li et al, 2005;Osmanlioglu, 2006;Plecas and Dimovic, 2006;Plecas et al, 2009). These mineral admixtures possess different properties and improve the performances of solidified waste forms in different ways.…”

Section: Introductionmentioning

confidence: 98%

Optimization of composite admixtures used in cementation formula for radioactive evaporator concentrates

Sun

Wang

2014

Progress in Nuclear Energy

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“…Leach rates of 137 Cs solidified in OPC and grouts are relatively high compared to most other metals. Much research (see, for example, Bagnosi and Csetenyi 1999, Plecas et al 2009Plecas et al , 2004Plecas et al , 1992 has been performed on the addition of clays (e.g., kaolinite, bentonite) and zeolites (e.g., clinoptilolite) to the dry blend that strongly adsorbs cesium, generating tailored cement/grouts that can encapsulate spent resins containing 137 Cs so that acceptable leach performance is obtained. The high concentrations of cations that dissolve as the cement dry blend is wetted compete for adsorption sites on the spent resins, causing the release of adsorbed cesium from the wet cement-solidified resins both before and after curing.…”

Section: Review Of Cement Solidification Of Spent Resinsmentioning

confidence: 99%

Review of Potential Candidate Stabilization Technologies for Liquid and Solid Secondary Waste Streams

Pierce¹,

Mattigod²,

Westsik³

et al. 2010

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Executive SummaryPacific Northwest National Laboratory has initiated a waste-form testing program to support the longterm 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. Later, more comprehensive and longer term performance testing will be conducted, following the guidance provided by the secondary waste-form selection, development, and performance evaluation roadmap. The resulting waste form will be compliant to regulations and performance criteria and will lead to cost-effective disposal of the secondary wastes.This report starts with a brief review of some of the most commonly used solidification formulations that would be candidates for secondary liquid waste streams. In this review, the available data on performance are discussed, and some preliminary recommendations are provided for materials that should undergo additional screening testing. We also 1) discuss options for disposal of WTP secondary solid waste streams, 2) provide a brief overview of standard regulatory test methods used for measuring contaminant leachability and waste-form physical strength (with emphasis on the U.S. Environmental Protection Agency's [EPA's] new methods as a screening tool for comparing waste solidification materials of interest), and 3) provide an overview of factors that must be considered in long-term performance testing, including state-of-the-art characterization tools that can provide the data needed to technically defend predictive modeling simulations of long-term material behavior. The long-term wasteform testing and solid and leachate characterization must be robust enough to effectively predict material performance in the Integrated Disposal Facility over the 10,000-year period of performance for the engineered system. The solidification technologies for liquid waste streams include cement/grout, containerized Cast Stone, phosphate-bonded ceramics, alkali-aluminosilicate geopolymers, hydroceramics, L-TEM, and fluidized-bed steam reforming (FBSR). In addition to these, other mature technologies and two compounds, namely goethite and sodalite (that are still being developed), that show considerable promise as waste forms or getters are also discussed. It is our recommendation, based upon the available literature, that Cast Stone, chemically bonded phosphate ceramics (Ceramicrete...

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Influence of bentonite and zeolite in cementation of dry radioactive evaporator concentrates

Cited by 15 publications

References 13 publications

The Influence of Zeolite (Sokyrnytsya Deposit) on the Physical and Chemical Resistance of a Magnesium Potassium Phosphate Compound for the Immobilization of High-Level Waste

The Influence of Zeolite (Sokyrnytsya Deposit) on the Physical and Chemical Resistance of a Magnesium Potassium Phosphate Compound for the Immobilization of High-Level Waste

Optimization of composite admixtures used in cementation formula for radioactive evaporator concentrates

Review of Potential Candidate Stabilization Technologies for Liquid and Solid Secondary Waste Streams

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