Download or read book Design of a Carousel Process for Removing Cesium from SRS Waste Using Crystalline Silicotitanate Ion Exchanger written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Designs of a three-column carousel process based on crystalline silicotitanate (CST) ion exchanger have been developed for removing radioactive 137Cs+ from Savannah River Site's (SRS) nuclear wastes. A multicomponent ion exchange equilibrium model (Zheng et al., 1997) from Texas A & M University, which is based on batch data obtained from CST powder, is used to generate cesium loading data at different cesium concentrations for various types of SRS wastes. These loading data are fit to the Langmuir equation to obtain effective single-component cesium isotherm parameters. The predictions are in reasonable agreement with batch test data obtained from CST powder, an early CST pellet batch (38B), and a later batch (IE911) using two SRS waste simulants. The ratios between experimental cesium distribution coefficients and predicted values are between 0.56 and 1.0. The variation appears to be due to inadequate equilibration time in some of the batches. Mass transfer parameters are estimated by analyzing column data of a simulated SRS waste and Melton Valley Storage Tank W29 (MVST-W29) waste. The intraparticle diffusivity estimated for the two wastes can be well correlated by means of the Stokes-Einstein equation. Simulations are performed to determine the length of the mass transfer zone for given feed compositions, Cs+ concentrations, and linear velocities. In order to ensure high column utilization during both the transient and cyclic steady state periods, the length of a single segment in the carousel process is chosen to be the mass transfer zone length after the concentration wave achieves a constant pattern. Analysis of the dimensionless groups in the differential mass balance equations reveals that the normalized mass transfer zone length is linearly proportional to the particle Peclet number. The proportionality constant is a function of the waste composition and the Cs+ concentration in the waste. The higher the effective Cs+ capacity and the higher the Cs+ concentration, the smaller the proportionality constant. This dimensionless group analysis allows one to easily adjust designs for variations in particle size, linear velocity, and intraparticle diffusivity.

Download or read book Cesium Removal from Simulated SRS High Level Waste Using Crystalline Silicotitanate written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study measured the adsorption of cesium from simulated Savannah River Site liquid waste onto crystalline silicotitanate (CST) in equilibrium (Kd) and ion exchange column tests.

Download or read book Small Column Ion Exchange Analysis for Removal of Cesium from SRS Low Curie Salt Solutions Using Crystalline Silicotitanate CST Resin written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Savannah River Technology Center (SRTC) researchers modeled ion exchange removal of cesium from dissolved salt waste solutions. The results assist in evaluating proposed configurations for an ion exchange process to remove residual cesium from low curie waste streams. A process for polishing (i.e., removing small amounts) of cesium may prove useful should supernate draining fail to meet the Low Curie Salt (LCS) target limit of 0.1 Ci of Cs-137 per gallon of salt solution. Cesium loading isotherms and column breakthrough curves for Low Curie dissolved salt solutions were computed to provide performance predictions for various column designs.

Download or read book Modeling of Crystalline Silicotitanate Ion Exchange Columns written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-elutable ion exchange is being considered as a potential replacement for the In-Tank Precipitation process for removing cesium from Savannah River Site (SRS) radioactive waste. Crystalline silicotitanate (CST) particles are the reference ion exchange medium for the process. A major factor in the construction cost of this process is the size of the ion exchange column required to meet product specifications for decontaminated waste. To validate SRS column sizing calculations, SRS subcontracted two reknowned experts in this field to perform similar calculations: Professor R.G. Anthony, Department of Chemical Engineering, Texas A & 038;M University, and Professor S.W. Wang, Department of Chemical Engineering, Purdue University. The appendices of this document contain reports from the two subcontractors. Definition of the design problem came through several meetings and conference calls between the participants and SRS personnel over the past few months. This document summarizes the problem definition and results from the two reports.

Download or read book Preliminary Ion Exchange Modeling for Removal of Cesium from Hanford Waste Using Hydrous Crystalline Silicotitanate Material written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the current pretreatment facility design of the River Protection Project (RPP) Waste Treatment Plant (WTP), the removal of cesium from low activity waste (LAW) is achieved by ion-exchange technology based on SuperLig(R) 644 resin. Due to recent concerns over potential radiological and chemical degradation of SuperLig(R) 644 resin and increased pressure drops observed during pilot-scale column studies, an increased interest in developing a potential backup ion-exchanger material has resulted. Ideally, a backup ion-exchanger material would replace the SuperLig(R) 644 resin and have no other major impacts on the pretreatment facility flowsheet. Such an ideal exchanger has not been identified to date. However, Crystalline Silicotitanate (CST) ion-exchanger materials have been studied for the removal of cesium from a variety of DOE wastes over the last decade. CST ion-exchanger materials demonstrate a high affinity for cesium under high alkalinity conditions and have been under investigation for cesium removal specifically at Hanford and SRS during the last six years. Since CST is an inorganic based material (with excellent properties in regard to chemical, radiological, and thermal stability) that is considered to be practically non-elutable (while SuperLig(R) 644 is an organic based elutable resin), the overall pretreatment facility flowsheet would be impacted in various ways. However, the CST material is still being considered as a potential backup ion-exchanger material. The performance of a proposed backup ion-exchange column using IONSIV IE-911 (CST in its engineered-form) material for the removal of cesium from Hanford high level radioactive alkaline waste is discussed. This report focuses attention on the ion-exchange aspects and addresses the loading phase of the process cycle.

Download or read book Modeling of Crystalline Silicotitanate Ion Exchange Columns Using Experimental Data from SRS Simulated Waste written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-elutable ion exchange using crystalline silicotitanate is being considered for removing cesium from Savannah River Site radioactive waste. The construction cost of this process depends strongly on the size of the ion exchange column required to meet product specifications.

Download or read book Cesium Removal Using Crystalline Silicotitanate Innovative Technology Summary Report written by and published by . This book was released on 1999 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approximately 100 million gallons of radioactive waste is stored in underground storage tanks at the Hanford Site, Idaho National Engineering and Environmental Laboratory (INEEL), Oak Ridge Reservation, and Savannah River Site (SRS). Most of the radioactivity comes from 137Cs, which emits high-activity gamma radiation. The Cesium Removal System is a modular, transportable, ion-exchange system configured as a compact processing unit. Liquid tank waste flows through columns packed with solid material, called a sorbent, that selectively adsorbs cesium and allows the other materials to pass through. The sorbent is crystalline silicotitanate (CST), an engineered material with a high capacity for sorbing cesium from alkaline wastes. The Cesium Removal System was demonstrated at Oak Ridge using Melton Valley Storage Tank (MVST) waste for feed. Demonstration operations began in September 1996 and were completed during June 1997. Prior to the demonstration, a number of ion-exchange materials were evaluated at Oak Ridge with MVST waste. Also, three ion-exchange materials and three waste types were tested at Hanford. These bench-scale tests were conducted in a hot cell. Hanford's results showed that 300 times less sorbent was used by selecting Ionsiv IE-911 over organic ion-exchange resins for cesium removal. This paper gives a description of the technology and discusses its performance, applications, cost, regulatory and policy issues and lessons learned.

Download or read book An Optimal Ion Exchange Design for Removal of Cesium from Hanford Waste written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-elutable crystalline silicotitanate (CST) ion-exchanger materials have been studied for removing cesium from a variety of radioactive wastes at several U.S. DOE sites over the last decade. For the current pretreatment facility design of the River Protection Project (RPP) Waste Treatment Plant (WTP) in Hanford, the removal of cesium from low activity waste (LAW) is achieved by ion-exchange technology based on SuperLig(R) 644 resin. However, due to concerns over potential radiological and chemical degradation of SuperLig(R) 644 resin, IONSIV IE-911 (CST in its engineered form) material is being proposed as a backup ion-exchange material for the removal of cesium from Hanford radioactive waste. This paper discusses the methodology used to determine the optimal CST ion-exchange column size to process all 16 separate batches of feeds from the ten targeted Hanford waste tanks. The optimal design ensures the best utilization of CST material and therefore results in a minimum amount of spent CST.

Download or read book Small Column Ion Exchange Design and Safety Strategy written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Small Column Ion Exchange (SCIX) is a transformational technology originally developed by the Department of Energy (DOE) Environmental Management (EM-30) office and is now being deployed at the Savannah River Site (SRS) to significantly increase overall salt processing capacity and accelerate the Liquid Waste System life-cycle. The process combines strontium and actinide removal using Monosodium Titanate (MST), Rotary Microfiltration, and cesium removal using Crystalline Silicotitanate (CST, specifically UOP IONSIV{reg_sign}IE-911 ion exchanger) to create a low level waste stream to be disposed in grout and a high level waste stream to be vitrified. The process also includes preparation of the streams for disposal, e.g., grinding of the loaded CST material. These waste processing components are technically mature and flowsheet integration studies are being performed including glass formulations studies, application specific thermal modeling, and mixing studies. The deployment program includes design and fabrication of the Rotary Microfilter (RMF) assembly, ion-exchange columns (IXCs), and grinder module, utilizing an integrated system safety design approach. The design concept is to install the process inside an existing waste tank, Tank 41H. The process consists of a feed pump with a set of four RMFs, two IXCs, a media grinder, three Submersible Mixer Pumps (SMPs), and all supporting infrastructure including media receipt and preparation facilities. The design addresses MST mixing to achieve the required strontium and actinide removal and to prevent future retrieval problems. CST achieves very high cesium loadings (up to 1,100 curies per gallon (Ci/gal) bed volume). The design addresses the hazards associated with this material including heat management (in column and in-tank), as detailed in the thermal modeling. The CST must be size reduced for compatibility with downstream processes. The design addresses material transport into and out of the grinder and includes provisions for equipment maintenance including remote handling. The design includes a robust set of nuclear safety controls compliant with DOE Standard (STD)-1189, Integration of Safety into the Design Process. The controls cover explosions, spills, boiling, aerosolization, and criticality. Natural Phenomena Hazards (NPH) including seismic event, tornado/high wind, and wildland fire are considered. In addition, the SCIX process equipment was evaluated for impact to existing facility safety equipment including the waste tank itself. SCIX is an innovative program which leverages DOE's technology development capabilities to provide a basis for a successful field deployment.

Download or read book Ion Exchange Modeling of Crystalline Silicotitanate IONSIV R IE 911 Column for Cesium Removal from Argentine Waste written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Department of Energy (DOE) and the Nuclear Energy Commission of Argentina (CNEA) have a collaborative project to separate cesium/strontium from waste resulting from the production of Mo-99. The Pacific Northwest National Laboratory (PNNL) is assisting DOE on this joint project by providing technical guidance to CNEA scientists. As part of the collaboration, PNNL staff works with staff at the Savannah River Technology Center (SRTC) to run the VERSE-LC model for removal of cesium from the Mo-99 waste using the crystalline silicotitanate (CST) material (IONSIV(R) IE-911, UOP LLC, DesPlaines, IL) based on technical data provided by CNEA. This report discusses the VERSE-LC ion-exchange-column model and the predicted results of CNEA test cases.

Download or read book MODELING OF ION EXCHANGE FOR CESIUM REMOVAL FROM DISSOLVED SALTCAKE IN SRS TANKS 1 3 37 AND 41 written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents an evaluation of the expected performance of engineered Crystalline Silicotitanate (CST) and spherical Resorcinol-Formaldehyde (RF) ion exchange resin for the removal of cesium from dissolved saltcake in SRS Tanks 1-3, 37 and 41. The application presented in this report reflects the expected behavior of engineered CST IE-911 and spherical RF resin manufactured at the intermediate-scale (approximately 100 gallon batch size; batch 5E-370/641). It is generally believed that scale-up to production-scale in RF resin manufacturing will result in similarly behaving resin batches whose chemical selectivity is unaffected while total capacity per gram of resin may vary. As such, the predictions provided within this report should provide reasonable estimates of production-scale column performance. Two versions of the RF cesium isotherm were used. The older version provides a conservative estimate of the resin capacity while the newer version more accurately fits the most recent experimental data.

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Download or read book Cesium Removal Demonstration Utilizing Crystalline Silicotitanate Sorbent for Processing Melton Valley Storage Tank Supernate Final Report written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides details of the Cesium Removal Demonstration (CsRD), which was conducted at Oak Ridge National Laboratory (ORNL) on radioactive waste from the Melton Valley Storage Tanks. The CsRD was the first large-scale use of state-of-the-art sorbents being developed by private industry for the selective removal of cesium and other radionuclides from liquid wastes stored across the DOE complex. The crystalline silicotitanate sorbent used in the demonstration was chosen because of its effectiveness in laboratory tests using bench-scale columns. The demonstration showed that the cesium could be removed from the supernate and concentrated on a small-volume, solid waste form that would meet the waste acceptance criteria for the Nevada Test Site. During this project, the CsRD system processed> 115,000 L (30,000 gal) of radioactive supernate with minimal operational problems. Sluicing, drying, and remote transportation of the sorbent, which could not be done on a bench scale, were successfully demonstrated. The system was then decontaminated to the extent that it could be contact maintained with the use of localized shielding only. By utilizing a modular, transportable design and placement within existing facilities, the system can be transferred to different sites for reuse. The initial unit has now been removed from the process building and is presently being reinstalled for use in baseline operations at ORNL.

Download or read book Performance of Crystalline Silicotitanates for Cesium Removal from Hanford Tank Waste Simulants written by and published by . This book was released on 1994 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new class of inorganic ion exchangers, called crystalline silicotitanates (CSTs), has been prepared at Sandia National Laboratories and Texas A & M University. CSTs have been determined to have high selectivity for the adsorption of Cs and Sr, and several other radionuclides from highly alkaline, high-sodium supernate solutions such as those found at Westinghouse Hanford (WHC). Continuous flow, ion-exchange columns are expected to be used to remove Cs and other radionuclides from the Hanford tank supernate. The proposed application for the CST would be Cs removal from highly alkaline salt solutions in a single pass process with interim storage of the Cs loaded CST until the glass vitrification plant is operational. This paper presents test results which address material requirements relevant for Hanford radwaste processing. This paper also discusses the integrated experimental and modeling approach being developed to establish the performance of the CST materials for the range of solution compositions and processing conditions which are expected to occur. The status on the commercialization of the CST material is also discussed.

Download or read book Vitrification of Ion Exchange Materials Innovative Technology Summary Report written by and published by . This book was released on 1999 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion exchange is a process that safely and efficiently removes radionuclides from tank waste. Cesium and strontium account for a large portion of the radioactivity in waste streams from US Department of Energy (DOE) weapons production. Crystalline silicotitanate (CST) is an inorganic sorbent that strongly binds cesium, strontium, and several other radionuclides. Developed jointly by Sandia National Laboratory and Texas A and M University, CST was commercialized through a cooperative research and development agreement with an industrial partner. Both an engineered (mesh pellets) and powdered forms are commercially available. Cesium removal is a baseline in HLW treatment processing. CST is very effective at removing cesium from HLW streams and is being considered for adoption at several sites. However, CST is nonregenerable, and it presents a significant secondary waste problem. Treatment options include vitrification of the CST, vitrification of the CST coupled with HLW, direct disposal, and low-temperature processes such as grouting. The work presented in this report demonstrates that it is effective to immobilize CST using a baseline technology such as vitrification. Vitrification produces a durable waste form. CST vitrification was not demonstrated before 1996. In FY97, acceptable glass formulations were developed using cesium-loaded CST obtained from treating supernatants from Oak Ridge Reservation (ORR) tanks, and the CST was vitrified in a research melter at the Savannah River Technology Center (SRTC). In FY98, SRS decided to reevaluate the use of in-tank precipitation using tetraphenylborate to remove cesium from tank supernatant and to consider other options for cesium removal, including CST. Hanford and Idaho National Engineering and Environmental Laboratory also require radionuclide removal in their baseline flowsheets.

Download or read book Small Column Ion Exchange Alternative to Remove 137Cs from Low Curie Salt Waste written by Walker, JR. (J. F.) and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A Small-Column Ion-Exchange (SCIX) system is being evaluated for removing cesium from the Type 2 and/or Type 3 dissolved saltcake wastes at the Savannah River Site (SRS) to ensure that the dissolved saltcake meets the waste acceptance criteria at the Saltstone Facility. Both crystalline silicotitanate (CST) and IONSIV{trademark} IE-96 zeolite were evaluated as the ion-exchange media. The accelerated alternative, using CST in the SCIX, could save as much as $3 billion in operating and storage costs and {approx}20 years in processing time compared to the current baseline. With its proven high cesium-loading capacity for the expected dissolved saltcake compositions and temperatures, CST is the preferred sorbent for SCIX. The low-cost alternative sorbent, zeolite, greatly increases the volume of sorbent required because of its much lower cesium-loading capacity. Thus, zeolite greatly increases the cost for the alternative, mainly because of the increased number of Defense Waste Processing Facility canisters required to dispose of the loaded sorbent (potentially over 7000 for zeolite, compared with

Download or read book Preliminary Ion Exchange Modeling for Removal of Cesium from Hanford Waste Using SuperLig 644 Resin written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A proposed facility is being designed for the immobilization of Hanford high-level radioactive waste. One unit process in the facility is designed to remove radioactive cesium by ion-exchange from the strongly alkaline aqueous phase. A resin specifically designed with high selectivity of cesium under alkaline conditions is being investigated. The resin also is elutable under more acidic conditions. The proposed design of the facility consists of two sets of two packed columns placed in series (i.e., a lead column followed by a lag (guard) column configuration). During operation, upon reaching a specified cesium concentration criterion at the exit of the lag column, operation is switched to the second set of lead and lag columns. The cesium-loaded lead column is processed (i.e., washed and eluted) and switched to the lag position. the previous lag column is then placed in the lead position (without eluting) and the system is ready for use in the next cycle. For a well designed process, the loading and elution processes result in significant volume reductions in aqueous high-level waste.