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At least 1,099 records · Page 61
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Process and equipment development for hot isostatic pressing treatability study

Battelle Energy Alliance (BEA), LLC, has developed processes and equipment for a pilot-scale hot isostatic pressing (HIP) treatability study to stabilize and volume reduce radioactive calcine stored at Idaho National Laboratory (INL). In 2009, the U. S. Department of Energy signed a Record of Decision with the state of Idaho selecting HIP technology as the method to treat 5,800 yd^3 (4,400 m^3) of granular zirconia and alumina calcine produced between 1953 and 1992 as a waste byproduct of spent nuclear fuel reprocessing. Since the 1990s, a variety of radioactive and hazardous waste forms have been remotely treated using HIP within INL hot cells. To execute the remote process at INL, waste is loaded into a stainless-steel or aluminum can, which is evacuated, sealed, and placed into a HIP furnace. The HIP simultaneously heats and pressurizes the waste, reducing its volume and increasing its durability. Two 1 gal cans of calcine waste currently stored in a shielded cask were identified as candidate materials for a treatability study involving the HIP process. Equipment and materials for cask-handling and calcine transfer into INL hot cells, as well as remotely operated equipment for waste can opening, particle sizing, material blending, and HIP can loading have been designed and successfully tested. These results demonstrate BEA’s readiness for treatment of INL calcine.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

DECOVALEX-2015: an international collaboration for advancing the understanding and modeling of coupled thermo-hydro-mechanical-chemical (THMC) processes in geological systems

Here, an important part of the performance and safety assessment of disposal systems for radioactive waste and spent nuclear fuel in deep geological formations is to evaluate the impact of the coupled effects of mechanical deformation, fluid and gas flow through the repository, and thermal loading from the decaying waste. It was recognized early on in safety and performance assessments conducted for geologic disposal sites that to be able to conduct such an evaluation, there was a need to rigorously enhance the theoretical background and to develop models capable of simulating coupled thermo-hydro-mechanical (THM) processes. More recently, chemical processes have also been added to enable the study of fully coupled THMC processes in geosystems.

58 GEOSCIENCES↗
DOE OSTI2017

Removal of Tritium from the Gaseous Effluents Produced by the Recovery of Zirconium from Used Fuel Cladding

U.S. regulations will require the removal of tritium ({sup 3}H) from gaseous effluents associated with nuclear fuel reprocessing and recycling. One process that may generate {sup 3}H-containing gaseous effluents is the recovery of zirconium from used fuel cladding. A chlorination process developed by Collins et al. is designed to convert the zirconium present in Zircaloy{sup R} cladding to recoverable ZrCl{sub 4}. The greatest economic benefit from including zirconium recycle as part of a larger used nuclear fuel (UNF) recycle effort would be a decrease in the disposal cost of used fuel cladding. Used fuel cladding is considered high-level waste (HLW). As zirconium is the second largest element by mass (25%) contained in most UNF assemblies (with uranium being the largest), recovery of the zirconium could result in a substantial decrease in the amount of HLW intended for geologic disposition. The reclaimed ZrCl{sub 4} product, if sufficiently free from radioactive impurities, could then be disposed of as low-level waste or reused in nuclear applications. The chlorination process uses chlorine gas (Cl{sub 2}) and an inert carrier such as argon (Ar) to convert the zirconium present in cladding to ZrCl{sub 4}. ZrCl{sub 4} is more volatile than other components in the cladding, causing evaporation of a relatively pure gaseous ZrCl{sub 4} stream. The product ZrCl{sub 4} is recovered as a solid salt by condensation when cooled to less than about 300 deg. C. A fraction of the {sup 3}H (0-96%) produced in nuclear fuel during irradiation is found in zirconium-based cladding, possibly as zirconium hydride (the wide range is a remnant of various researchers' analyses of cladding of various irradiations and cooling times). Heating the cladding to high temperatures, such as would be done during the chlorination process, will release the {sup 3}H. At the temperatures of the zirconium recycle process, the {sup 3}H is likely to react with excess Cl{sub 2} to produce tritiated HCl ({sup 3}HCl), although this could be avoided if the cladding and fuel were treated to remove {sup 3}H prior to chlorination. A previous analysis showed that the concentration of {sup 3}HCl in the off-gas of the zirconium recycle process will be in the range of parts per billion to a few parts per million. Should {sup 3}H mitigation be required for the zirconium recycle process, it will be completed through the abatement of {sup 3}HCl from this off-gas stream. The intent of the testing described in this summary was to conduct proof-of-principle demonstrations for two {sup 3}HCl removal methods. The zirconium recycle off-gas stream differs from many industrial HCl-containing streams in that the concentration of HCl requiring removal is extremely low. Demonstrations of HCl removal at ppm concentrations were not found in the literature, making the proof-of-principle approach attractive as a way to identify the most promising method for continued development. An important consideration throughout these experiments was that current research efforts on the zirconium recycle process are conducted in a hot cell and any {sup 3}HCl removal methods should be easily deployed in a hot-cell environment.

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DOE OSTI2021

Modeling the Fundamental Radiation Chemistry of the Organic Diluent, and the Effect of Metal Ion Complexation on the Radiochemical Behavior of Active Compounds

All used nuclear fuel (UNF) reprocessing technologies must operate efficiently in the presence of an intense, multi-component (predominantly alpha, beta, and gamma) radiation field. Consequently, radiation-induced degradation of reprocessing systems is of concern, as it negatively impacts process performance over time due to the destruction of both active compounds (ligands, phase modifiers, holdback agents, etc.) and the formation of degradation products. Reprocessing solvent system radiolysis has been linked to changes in separation efficiency and physical properties of solvent mixtures, solvent-recycle longevity, crud formation, and other unexpected outcomes that impact the efficient recovery of valuable materials (e.g., the actinides) and the volume of hazardous radioactive waste for final disposal, i.e., in a geological repository. Consequently, a fundamental understanding of radiolytic processes and their effects on reprocessing solvent system performance is critical for: (i) the cost-effective development and innovation of separation technologies; (ii) the design and implementation of predictive radiation chemical models for process monitoring and lifetimes; and (iii) potentially the ability to exploit radiolytic phenomenon to our benefit, e.g., strategic radiolysis of active molecules to liberate specific degradation products that aid subsequent process stages. Despite extensive investigation into the radiolytic behavior of active solvent system compounds, little attention has been given to understanding (i) the radiation chemical behavior and modification of the organic diluent and (ii) the effect of metal ion complexation on the radiochemical behavior of active compounds.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2016

Technetium Management for Hanford Tank Waste Processing and Disposition - 16399

Technetium-99 (Tc) generated from the fission of {sup 235}U and {sup 239}Pu in high yields is one of the most difficult contaminants to be addressed at the U.S. Department of Energy (DOE) Hanford Site. Among radioactive constituents in the tank waste, Tc presents a unique challenge in that it is radio-toxic (β = 292 keV), has a long half-life (T{sub 1/2} = 2.11x10{sup 5} y), and exists predominantly in the liquid fraction of the alkaline tank waste, generally in the anionic form of pertechnetate TcO{sub 4}{sup -}, which is highly volatile at low-activity waste vitrification melter temperatures and mobile in the subsurface environment. This makes immobilization of Tc into high-durability waste forms a critical technical challenge for nuclear waste management. The complex behavior of Tc under storage, treatment, and immobilization conditions significantly affects its management options. The overall objective of the Technetium Management program is to provide the DOE Office of Environmental Management with practical solutions to Tc needs encountered in the processing of Hanford tank waste. To reduce the technical uncertainty associated with the long-term environmental impact of Tc, a systems-based approach is needed to address Tc management needs by evaluating and developing science and engineering options for treatment, immobilization, and disposition of Tc contained in Hanford tank wastes. This paper describes major elements of Technetium Management program, including: - Identifying the chemical forms of Tc in tank waste through analytical speciation of low-valent Tc(I) species in alkaline solutions. - Performing proof-of-concept demonstration for detection of low-valent Tc(I) by fluorescence spectroscopy. - Identifying alternative non-glass Tc immobilization methods. (authors)

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DOE OSTI2012

Managing Waste Inventory and License Limits at the Perma-Fix Northwest Facility to Meet CH2M Hill Plateau Remediation Company (CHPRC) American Recovery and Reinvestment Act (ARRA) Deliverables - 12335

CH2M Hill Plateau Remediation Company (CHRPC) is a prime contractor to the U.S. Department of Energy (DOE) focused on the largest ongoing environmental remediation project in the world at the DOE Hanford Site Central Plateau, i.e. the DOE Hanford Plateau Remediation Contract. The East Tennessee Materials and Energy Corporation (M and EC); a wholly owned subsidiary of Perma-Fix Environmental Services, Inc. (PESI), is a small business team member to CHPRC. Our scope includes project management; operation and maintenance of on-site storage, repackaging, treatment, and disposal facilities; and on-site waste management including waste receipt from generators and delivery to on-site and off-site treatment, storage, and disposal facilities. As part of this scope, M and EC staffs the centralized Waste Support Services organization responsible for all waste characterization and acceptance required to support CHPRC and waste generators across the Hanford Site. At the time of the CHPRC contract award (August 2008) slightly more than 9,000 cubic meters (m{sup 3}) of legacy waste was defined as 'no-path-forward waste'. A significant portion of this waste (7,650 m{sup 3}) comprised wastes with up to 50 grams of special nuclear materials (SNM) in oversized packages recovered during retrieval operations and large glove boxes removed from the Plutonium Finishing Plant (PFP). Through a collaborative effort between the DOE, CHPRC, and Perma-Fix Environmental Services, Inc. (PESI), pathways for these problematic wastes were developed that took advantage of commercial treatment capabilities at a nearby vendor facility, Perma-Fix Northwest (PFNW). In the spring of 2009, CHPRC initiated a pilot program under which they began shipping large package, low gram suspect TRU (<15 g SNM per container), and large package contact and remote handled MLLW to the off-site PFNW facility for treatment. PFNW is restricted by the SNM limits set for the total quantity of SNM allowed at the facility in accordance with the facility's radioactive materials license(s) (RML). While both CHPRC and PFNW maintain waste databases to track all waste movements, it became evident early in the process that a tool was needed that married the two systems to better track SNM inventories and sequence waste from the point of generation, through the PFNW facility, and back to the Hanford site for final disposition. This tool, known as the Treatment Integration and Planning Tool (TIPT), has become a robust planning tool that provides real-time data to support compliant and efficient waste generation, transportation, treatment, and disposition. TIPT is developing into the next generation tool that will change the way in which legacy wastes, retrieval wastes and decontamination and decommissioning operations are conducted on the Plateau Remediation Contract (PRC). The real value of the TIPT is its predictive capability. It allows the W and FMP to map out optimal windows for processing waste through the PFNW facility, or through any process that is in some way resource limited. It allows project managers to identify and focus on problem areas before shipments are affected. It has been modified for use in broader applications to predict turnaround times and identify windows of opportunity for processing higher gram wastes through PFNW and to allow waste generators, site-wide, to accurately predict scope, cost, and schedule for waste generation to optimize processing and eliminate storage, double handling, and related costs and unnecessary safety risks. The TIPT addresses the years old problem of how to effectively predict not only what needs to be done, but when. 'When' is the key planning parameter that has been ignored by the generator and processor for many years, but has proven to be the most important parameter for both parties. While further refinement is a natural part of any development process, the current improvements on the TIPT have shown that prediction is a powerful consideration. Even in lean times expected for the foreseeable future, the improved TIPT continues to play a central role in managing our way through those times to assure facilities remain viable and available. It is recommended that other major remediation projects and waste processing facilities incorporate a tool such as TIPT to improve customer-commercial supplier communications and better optimization of resources. (authors)

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DOE OSTI2015

H-Canyon facility remains a national asset after finding innovative solution to funding issues - 15278

In recent years, there has been an increase in the number of missions for the H-Canyon facility at the Savannah River Site, as its capabilities are being recognized as an increasingly important asset for the Department of Energy (U.S. DOE). The sustainability of that asset was called into question in 2011, when funding from U.S. DOE's Environmental Management (EM) program became insufficient to sustain processing. Through the acquisition of new customers, funding was restored and H Canyon missions have seen new life. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Advances in the glass formulations for the Hanford Tank Waste Treatment and Immobilization Plant - 15053

The Department of Energy-Office of River Protection (DOE-ORP) is constructing the Hanford Tank Waste Treatment and Immobilization Plant (WTP) to treat radioactive waste currently stored in underground tanks at the Hanford site in Washington. The WTP that is being designed and constructed by a team led by Bechtel National, Inc. (BNI) will separate the tank waste into High Level Waste (HLW) and Low Activity Waste (LAW) fractions with the majority of the mass (∼90%) directed to LAW and most of the activity (>95%) directed to HLW. The pretreatment process, envisioned in the baseline, involves the dissolution of aluminum-bearing solids so as to allow the aluminum salts to be processed through the cesium ion exchange and report to the LAW Facility. There is an oxidative leaching process to affect a similar outcome for chromium-bearing wastes. Both of these unit operations were advanced to accommodate shortcomings in glass formulation for HLW inventories. A by-product of this are a series of technical challenges placed upon materials selected for the processing vessels. The advances in glass formulation play a role in revisiting the flow sheet for the WTP and hence, the unit operations that were being imposed by minimal waste loading requirements set forth in the contract for the design and construction of the plant. Another significant consideration to the most recent revision of the glass models are the impacts on resolution of technical questions associated with current efforts for design completion. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Volatile species of technetium and rhenium during waste vitrification

Volatile loss of technetium (Tc) during vitrification of low-activity wastes is a technical challenge for treating and immobilizing the large volumes of radioactive and hazardous wastes stored at the U.S. Department of Energy's Hanford Site. There are various research efforts being pursued to develop technologies that can be implemented for cost effective management of Tc, including studies to understand the behavior of Tc during vitrification, with the goal of eventually increasing Tc retention in glass. Furthermore, one of these studies has focused on identifying the form or species of Tc and Re (surrogate for Tc) that evolve during the waste-to-glass conversion process. This information is important for understanding the mechanism of Tc volatilization. In this paper, available information collected from the literature is critically evaluated to clarify the volatile species of Tc and Re and, more specifically, whether they volatilize as alkali pertechnetate and perrhenate or as technetium and rhenium oxides after decomposition of alkali pertechnetate and perrhenate. The evaluated data ranged from mass spectrometric identification of species volatilized from pure and binary alkali pertechnetate and perrhenate salts to structural and chemical analyses of volatilized materials during crucible melting and scaled melter processing of simulated wastes.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

The NAC-SMP - a Next Generation Transformation Package - 18391

NAC International Inc. (NAC) is developing a Small Multi-Purpose (SMP) Type B(U)F-96 transportation cask designed with flexibility and cost-efficiency objectives to support shipment of a wide range of wastes with fissile material contents. The NAC-SMP package is a small, modular design that meets US DOT weight limits for road transport. Contents can be accommodated in multiple configurations including standard drums of up to 416 liters (110 U.S. gallons) in capacity. The package will also accommodate unique waste contents and fuel designs where cost-effective packaging options have been a challenge. The NAC-SMP development goals include simplicity of design and operational flexibility to meet Type B requirements. In particular, the cask body is designed to satisfy the dimensional and mass constraints, shielding requirements, and general transport requirements for a variety of contents under 10 CFR 71 and IAEA SSR-6 regulations. Flexibility is assured by the cask's modular design, which consists of multiple vessels to provide containment, shielding and overpack capability. The containment boundary design permits adaptability to content requirements by relying on interchangeable internal components for secondary containment, supplemental shielding and shoring, as required. In this paper, NAC provides an overview of the NAC-SMP cask and identifies the design features and technology advancements that makes the cask a readily adaptable and flexible solution for packaging US DOE and other orphan wastes, and to enable the integration of these wastes into the waste management system process and disposition infrastructure. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

H-Canyon Dissolver Offgas Monitoring Using Raman Spectroscopy

This report describes the development and in facility demonstration of a Raman spectrometer to monitor known aluminum offgas components generated during the dissolution of Spent Nuclear Fuel at the Savannah River Site H-Canyon facility. The presence of these gases is an indicator that material is actively being dissolved. This process monitoring technique, which measures the offgas in real time, has the potential to improve the efficiency of facility operations. If the dissolution time is too short, time is wasted due to extended dissolution periods with additional probing of the dissolver pot to confirm that fragment levels are below the thresholds for continuing to the next charge or moving the dissolvent to a receiving tank. If the dissolution time is too long, time and energy are wasted.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Waste minimization efforts at the H-Canyon nuclear materials processing facility located at the Savannah River Site - 15535

During the last decade, the H-Canyon at the Savannah River Site (SRS) has employed various means to minimize liquid waste generation and/or to segregate liquid waste that favors generation of low level vs high level wastes. The primary drivers were cost reduction and support of SRS liquid waste tank farm feed to the SRS's Defense Waste Processing Facility. Recent High Level Waste (HLW) volume restrictions (transfers of liquid waste from the H-Canyon to the SRS's Liquid Waste System) imposed on H-Canyon have renewed waste minimization efforts. For the next several years, H-Canyon is faced with a HLW transfer reduction of approximately 65% (reduced from approximately 300,000 gallons to 100,000 gallons). This comes at a time when H-Canyon (and a companion facility named HB-Line) are about to begin executing two high profile missions. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Crystalline Silicotitanate (CST) Ion Exchange Media Performance Evaluations to Support TSCR DSA IX Media Equilibrium Contacts

The primary objective of this work is to calculate the maximum loading expected on the Hanford Tank Side Cesium Removal (TSCR) ion exchange columns. A key consideration in the design of the columns is the amount of 137 Cs that loads onto the Crystalline Silicotitanate (CST) and the heat generated by the loaded column during storage. Per request of Washington River Protection Solutions (WRPS), Savannah River National Laboratory (SRNL) has utilized ZAM, a computer program developed by the research group of Professor Rayford G. Anthony of Texas A&M University, to predict the cesium loading on the CST for a variety of waste compositions expected to be processed by TSCR. The study evaluated cesium loadings for the following waste compositions: 1. Seventeen DFLAW campaign batches to cover projected supernate composition ranges within which TSCR may be expected to operate within the first ten years, 2. Hanford tank AP-105 and AP-107 waste solutions that will be processed by the TSCR system.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Aluminum Solubility in Complex Electrolytes - 13011

Predicting aluminum solubility for Hanford and Savannah River waste liquids is very important for their disposition. It is a key mission goal at each Site to leach as much aluminum as practical from sludges in order to minimize the amount of vitrified high level waste. And it is correspondingly important to assure that any soluble aluminum does not precipitate during subsequent decontamination of the liquid leachates with ion exchange. This report shows a very simple and yet thermodynamic model for aluminum solubility that is consistent with a wide range of Al liquors, from simple mixtures of hydroxide and aluminate to over 300 Hanford concentrates and to a set of 19 Bayer liquors for temperatures from 20-100 deg. C. This dimer-dS{sub mix} (DDS) model incorporates an ideal entropy of mixing along with previous reports for the Al dimer, water activities, gibbsite, and bayerite thermodynamics. We expect this model will have broad application for nuclear wastes as well as the Bayer gibbsite process industry. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Erosion and corrosion analysis of waste transfer components in the POR104 valve box at Hanford - 15715

At the United States Department of Energy Hanford Site in Richland, Washington, waste is being transferred to storage tanks in preparation for treatment at the Waste Treatment and Immobilization Plant. Regulatory committees have concerns regarding the structural integrity of the waste transfer components being used. Washington River Protection Solutions (WRPS) has employed a Fitness-for-Service program, which is a multi-disciplinary engineering approach that is used to determine if equipment is fit to remain in operation for a specified projected period. An approach to monitor aging equipment is to take thickness measurements of components when feasible, to evaluate if there is any appreciable degradation in the integrity of the components. The thickness measurements can be used to determine if erosion or corrosion is occurring and predict the remaining lifespan of the components. These predictions can also be used to develop design modifications for new piping and pipe jumpers. Analysis of thickness measurements have been conducted on four floor nozzles in the POR104 valve box located in the C-Tank Farm at Hanford. The data for the floor nozzles of the valve box does not show signs of wear, but there are variations in thicknesses which are likely due to manufacturing processes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

From Radtrack to eMWaste(r) G2 process-based integration

This paper provides a process-based examination of the integration of two separate but related software applications into Sandia National Laboratories’ (SNL’s) Radioactive and Mixed Waste Management Facility’s (RMWMF) data management system. First, data collection will be upgraded through the use of a new web-based Waste Description and Disposal Request (WDDR), which SNL personnel whose work creates radioactive and hazardous waste (generators) will use to characterize dozens of specific attributes of each waste parcel. Second, a commercial software package for data storage and manipulation — eMWaste® G2 by Attention IT — will replace two existing software applications and will track all radioactive and mixed waste at Sandia. Integrating these applications into a web-based system will give the RMWMF increased system flexibility, reduced reliance on key personnel, and improved document control, traceability and efficiency. To meet these goals and ensure the applications are developed in an efficient, quality-oriented environment, it is critical to first conduct a thorough evaluation of the affected processes. This paper will analyze the processes supported by the new applications and the requirements for a successful integration. A comprehensive analysis of both project flow and data management requirements, illustrated through original flow diagrams and other charts, will provide support to the development team and programmers as they work to integrate the applications into the new system.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Incentivizing secondary raw material markets for sustainable waste management

Highlights: • An economic model of secondary raw material markets is presented. •Policies to enhance sustainable waste management at landfills are compared. • Correcting potential misperceptions of secondary raw materials seems quite promising. • Our theoretical model supports Circular Economy and landfilling mining initiatives. - Abstract: Notwithstanding several policy initiatives in many countries over a number of years, there remains a general sense that too much municipal solid waste is generated and that too much of the waste that is generated is landfilled. There is an emerging consensus that a sustainable approach to waste management requires further development of secondary raw material markets. The purpose of this paper is to propose a theoretical economic model that focuses upon this stage of a sustainable waste management program and explores policy options that could motivate efficiency in secondary raw material markets. In particular, we show how firm profit and social welfare optimizing objectives can be reconciled in a two-product market of waste management processes: landfilling and material reclamation. Our results provide theoretical support for building out recent Circular Economy initiatives as well as for the relatively recent emergence of landfill mining as a means for procuring secondary raw materials.

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