scholarly journals High Level Waste System Impacts from Small Column Ion Exchange Implementation

2005 ◽  
Author(s):  
D. J. McCabe ◽  
L. L. Hamm ◽  
S. E. Aleman ◽  
D. K. Peeler ◽  
C. C. Herman ◽  
...  
Keyword(s):  
Ion Exchange ◽  
High Level Waste ◽  
Small Column ◽  
High Level

Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

2010 ◽  
Vol 98 (6) ◽  
Author(s):  
R. Juncosa ◽  
I. Font ◽  
J. Delgado
Keyword(s):  
Ion Exchange ◽  
Radioactive Decay ◽  
Chemical Species ◽  
High Level Waste ◽  
Chemical Components ◽  
Clay Material ◽  
Decay Series ◽  
And Migration ◽  
High Level ◽  
Radioactive Species

AbstractRadioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion, ...) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption).In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture.

Characterization of Electroactive Cs Ion-Exchange Materials using XAS

1996 ◽  
Vol 465 ◽  
Author(s):  
N. J. Hess ◽  
J. H. Sukamto ◽  
S. D. Rassat ◽  
R. T. Hallen ◽  
R. J. Orth ◽  
...  
Keyword(s):  
Ion Exchange ◽  
High Level Waste ◽  
Cubic Phase ◽  
Loaded State ◽  
Single Use ◽  
Exchange Resins ◽  
High Level ◽  
Initial Results ◽  
Deposition Conditions

ABSTRACTVarious ion exchange materials have been proposed for the removal of Cs from high level waste streams produced during the reprocessing of fuel rods. Cs can be released from loaded traditional exchange resins by elution and then the resin can be reused. However large quantities of secondary wastes are generated. Another class of “single use” exchangers is directly incorporated in the loaded state into a solid waste form (e.g. borosilicate glass logs). A third alternative is electroactive ion-exchange materials, where the uptake and elution of Cs are controlled by an applied potential. This approach has several advantages over traditional reusable ion-exchange resins including much reduced secondary waste, higher Cs selectivity, and higher durability.XAS experiments were conducted at the Fe K-edge and Cs Lm-edge on a series of electrochemically produced nickel ferrocyanide films to determine the effects of deposition conditions and subsequent alkali exchange on structural and chemical aspects of the films. The deposition conditions include methods described in the literature and PNNL proprietary procedures. Although the performance and the durability of the films do vary with processing conditions, Fe K-edge EXAFS results indicate that all deposition conditions result in the. formation of the cubic phase. Initial results from Cs Lm-edge EXAFS analysis suggest that the Cs ion is present as a hydrated species.

Selective Radionuclide (Cs+, Sr2+, and Ni2+) Ion-exchange by K2xMgxSn3-xS6(x=0.5-0.95) (KMS-2)

2010 ◽  
Vol 1265 ◽  
Author(s):  
Joshua Leighton Mertz ◽  
Emmanouil J. Manos ◽  
Mercouri Kanatzidis
Keyword(s):  
Ion Exchange ◽  
Inductively Coupled Plasma ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
High Level Waste ◽  
Inductively Coupled ◽  
Inorganic Ion ◽  
The Stability ◽  
High Level

Abstract137Cs and90Sr, both byproducts of the fission process, make up the majority of high-level waste from nuclear power plants.63Ni is a byproduct of the erosion-corrosion process of the reactor components in nuclear energy plants. The concentrations of these ions in solution determine the Waste Class (A,B, or C) and thus selective removal of these ions over large excesses of other ions is necessary to reduce waste and cut costs. Herein we report the use of the Inorganic Ion Specific Media (ISM) K2xMgxSn3-xS6(x=0.5-0.9) (KMS-2) for the ion exchange of Cs+, Sr2+, and Ni2+in several different conditions. We will also report the stability of this new material in the general conditions found at nuclear power plants (pH ˜6-8) and DOE sites (pH>10). Measurements at low concentrations were conducted with inductively coupled plasma mass spectrometry and Kd values are reported for each of the ions in a variety of conditions.

scholarly journals Status of the Development of In-Tank/At-Tank Separations Technologies for High-Level Waste Processing for the U.S. Department of Energy

2011 ◽  
Author(s):  
William R. Wilmarth ◽  
Nicholas P. Machara ◽  
Reid A. Peterson ◽  
Sheryl R. Bush
Keyword(s):  
South Carolina ◽  
Ion Exchange ◽  
Development Program ◽  
High Level Waste ◽  
Waste Processing ◽  
Savannah River ◽  
Separation Processes ◽  
Processing Facility ◽  
High Level ◽  
The U.S

Within the U.S. Department of Energy’s (DOE) Office of Technology Innovation and Development, the Office of Waste Processing manages a research and development program related to the treatment and disposition of radioactive waste. At the Savannah River (South Carolina) and Hanford (Washington) Sites, approximately 90 million gallons of waste are distributed among 226 storage tanks (grouped or collocated in “tank farms”). This waste may be considered to contain mixed and stratified high activity and low activity constituent waste liquids, salts and sludges that are collectively managed as high level waste (HLW). A large majority of these wastes and associated facilities are unique to the DOE, meaning many of the programs to treat these materials are “first-of-a-kind” and unprecedented in scope and complexity. As a result, the technologies required to disposition these wastes must be developed from basic principles, or require significant reengineering to adapt to DOE’s specific applications. Of particular interest recently, the development of In-tank or At-Tank separation processes have the potential to treat waste with high returns on financial investment. The primary objective associated with In-Tank or At-Tank separation processes is to accelerate waste processing. Insertion of the technologies will (1) maximize available tank space to efficiently support permanent waste disposition including vitrification; (2) treat problematic waste prior to transfer to the primary processing facilities at either site (i.e., Hanford’s Waste Treatment and Immobilization Plant (WTP) or Savannah River’s Salt Waste Processing Facility (SWPF)); and (3) create a parallel treatment process to shorten the overall treatment duration. This paper will review the status of several of the R&D projects being developed by the U.S. DOE including insertion of the ion exchange (IX) technologies, such as Small Column Ion Exchange (SCIX) at Savannah River. This has the potential to align the salt and sludge processing life cycle, thereby reducing the Defense Waste Processing Facility (DWPF) mission by 7 years. Additionally at the Hanford site, problematic waste streams, such as high boehmite and phosphate wastes, could be treated prior to receipt by WTP and thus dramatically improve the capacity of the facility to process HLW. Treatment of boehmite by continuous sludge leaching (CSL) before receipt by WTP will dramatically reduce the process cycle time for the WTP pretreatment facility, wile treatment of posphate will significantly reduce the number of HLW borosilicate glass canisters produced at the WTP. These and other promising technologies will be discussed.

scholarly journals Numerical Simulation of Cesium and Strontium Migration Through Sodium Bentonite Altered by Cation Exchange with Groundwater Components

1988 ◽  
Vol 127 ◽  
Author(s):  
J. S. Jacobsen ◽  
C. L. Carnahan
Keyword(s):  
Numerical Simulation ◽  
Ion Exchange ◽  
Numerical Simulations ◽  
Cation Exchange ◽  
Fission Products ◽  
High Level Waste ◽  
Sodium Bentonite ◽  
Spatial And Temporal Changes ◽  
High Level ◽  
Exchange Properties

ABSTRACTNumerical simulations have been used to investigate how spatial and temporal changes in the ion exchange properties of bentonite affect the migration of cationic fission products from high-level waste. Simulations in which fission products compete for exchange sites with ions present in groundwater diffusing into the bentonite are compared to simulations in which the exchange properties of bentonite are constant.

Supernatant Treatment Considerations for the Neutralized Waste at West Valley

1982 ◽  
Vol 15 ◽  
Author(s):  
G. B. Gockley ◽  
E. J. Lahoda ◽  
J. M. Pope
Keyword(s):  
New York ◽  
Ion Exchange ◽  
Nuclear Fuel ◽  
Laboratory Data ◽  
High Level Waste ◽  
Inorganic Ion ◽  
Treatment Considerations ◽  
Exchange Resins ◽  
High Level ◽  
Nuclear Fuel Reprocessing Plant

ABSTRACTThe neutralized high-level waste, stored at the Western New York Nuclear Service Center in West Valley, New York, was produced during the operation of the Nuclear Fuel Service, Inc. commercial nuclear fuel reprocessing plant. The supernatant is a highly concentrated salt solution (NaNO3 , NaOH, Na2SO4 and NaCl) containing essentially all of the dissolved cesium as the primary radioactive component. The sludge is primarily iron and aluminum hydroxides and contains strontium and the bulk of the long-lived isotopes. The supernatant will be treated to remove essentially all of the radioactivity and then be concentrated and disposed of as low level nuclear waste. The following supernatant treatment considerations have been evaluated on a laboratory scale using simulated West Valley waste: 1) Organic ion exchange resins; 2) Inorganic ion exchange media; 3) In-tank processing. These processes will be described and preliminary laboratory data will be presented.

THOR® Steam Reforming Technology for the Treatment of Ion Exchange Resins and More Complex Wastes Such as Fuel Reprocessing Wastes

2010 ◽  
Author(s):  
J. Brad Mason ◽  
Corey A. Myers
Keyword(s):  
Ion Exchange ◽  
Steam Reforming ◽  
Waste Treatment ◽  
Full Scale ◽  
Radioactive Wastes ◽  
High Level Waste ◽  
Ion Exchange Resins ◽  
Savannah River ◽  
Exchange Resins ◽  
High Level

The THOR® fluidized bed steam reforming process has been successfully operated for more than 10 years in the United States for the treatment of low- and intermediate-level radioactive wastes generated by commercial nuclear power plants. The principle waste stream that has been treated is ion exchange resins (IER) and Dry Active Waste (DAW), but various liquids, sludges, and solid organic wastes have also been treated. The principle advantages of the THOR® process include: (a) high volume reduction on the order of 5:1 to 10:1 for IER and up to 50:1 for high plastic content DAW streams depending on the waste type and waste characteristics, (b) environmentally compliant off-gas emissions, (c) reliable conversion of wastes into mineralized products that are durable and leach-resistant, and (d) no liquid effluents for treatment of most radioactive wastes. Over the past ten years, the THOR® process has been adapted for the treatment of more complex wastes including historic defense wastes, reprocessing wastes, and other wastes associated with the fuel cycle. As part of the U.S. Department of Energy (DOE) environmental remediation activities, the THOR® dual bed steam reforming process has successfully processed: (a) Idaho National Laboratory (INL) Sodium-Bearing Waste (SBW), (b) Savannah River Tank 48 High Level Waste (HLW), (c) Hanford Low Activity Waste (LAW), and (d) Hanford Waste Treatment Plant Secondary Waste (WTP-SW) liquid slurry simulants. The THOR® process has been shown in pilot plant operations to successfully process various simulated liquid, radioactive, nitrate-containing wastes into environmentally safe, leach-resistant, solid mineralized products. These mineralized products incorporate normally soluble ions (e.g. - Na, K, Cs, Tc), sulfates, chloride salts, and fluoride salts into an alkali alumino-silicate mineral matrix that inhibits the leaching of those ions into the environment. The solid mineralized products produced by the THOR® process exhibit durability and leach resistance characteristics superior to borosilicate waste glasses. As a result of this work, a full-scale THOR® process facility is currently under construction at the DOE’s Idaho site for the treatment of SBW and a full-scale facility is in the final design stage for the DOE’s Savannah River Site for the treatment of Tank 48 high level waste. Recent work has focused on the development of new monolithic waste formulations, the extension of the THOR® process to new waste streams, and the development of modular THOR® processes for niche waste treatment applications. This paper will provide an overview of current THOR® projects and summarize the processes and outcomes of the regulatory and safety reviews that have been necessary for the THOR® process to gain acceptance in the USA.

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