13 research outputs found
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Characterization and Correlation of Particle-Level Interactions to the Macroscopic Rheology of Powders, Granular Slurries, and Colloidal Suspensions
This project had two primary objectives. The first was to understand the physical properties and behavior of select Hanford tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at the Waste Isolation Pilot Plant (WIPP). The second objective was to develop a fundamental understanding of these sludge suspensions by correlating the macroscopic properties with particle interactions occurring at the colloidal scale. The specific tank wastes considered herein are contained in thirteen Hanford tanks including three double-shell tanks (DSTs) (AW-103, AW-105, and SY-102) and ten single-shell tanks (SSTs) (B-201 through B-204, T-201 through T-204, T-110, and T-111). At the outset of the project, these tanks were designated as potentially containing transuranic (TRU) process wastes that would be treated and disposed of in a manner different from the majority of the tank wastes
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Scientific Opportunities to Reduce Risk in Nuclear Process Science
Cleaning up the nation’s nuclear weapons complex remains as one of the most technologically challenging and financially costly problems facing the U.S. Department of Energy (DOE). Safety, cost, and technological challenges have often delayed progress in retrieval, processing, and final disposition of high-level waste, spent nuclear fuel, and challenging materials. Some of the issues result from the difficulty and complexity of the technological issues; others have programmatic bases, such as contracting strategies that may provide undue focus on near-term, specific clean-up goals or difficulty in developing and maintaining stakeholder confidence in the proposed solutions. We propose that independent basic fundamental science research focused on the full cleanup life-cycle offers an opportunity to help address these challenges by providing 1) scientific insight into the fundamental mechanisms involved in currently selected processing and disposal options, 2) a rational path to the development of alternative technologies should the primary options fail, 3) confidence that models that predict long-term performance of different disposal options are based upon the best available science, 4) fundamental science discovery that enables transformational solutions to revolutionize the current baseline processes
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Estimate of Hanford Waste Rheology and Settling Behavior
The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment and Immobilization Plant (WTP) will process and treat radioactive waste that is stored in tanks at the Hanford Site. Piping, pumps, and mixing vessels have been selected to transport, store, and mix the high-level waste slurries in the WTP. This report addresses the analyses performed by the Rheology Working Group (RWG) and Risk Assessment Working Group composed of Pacific Northwest National Laboratory (PNNL), Bechtel National Inc. (BNI), CH2M HILL, DOE Office of River Protection (ORP) and Yasuo Onishi Consulting, LLC staff on data obtained from documented Hanford waste analyses to determine a best-estimate of the rheology of the Hanford tank wastes and their settling behavior. The actual testing activities were performed and reported separately in referenced documentation. Because of this, many of the required topics below do not apply and are so noted
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Physical Properties of Hanford Transuranic Waste Sludge
This project has two primary objectives. The first is to understand the physical properties and behavior of the Hanford transuranic (TRU) tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at WIPP. The second primary objective is to develop a fundamental understanding of these sludge suspensions by correlating the macroscopic properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of this research effort will enhance the existing understanding of agglomeration phenomena and the properties of complex colloidal suspensions. In addition, the knowledge gained and capabilities developed during this effort will aid in the development and optimization of techniques to process the wastes at various DOE sites. These objectives will be accomplished by: (1) characterizing the TRU sludges contained in the Hanford tanks that are intended for shipment to WIPP; (2) determining the physical behavior of the Hanford TRU tank sludges under conditions that might exist during treatment and packaging; (3) and modeling the retrieval, treatment, and packaging operations that will be performed at Hanford to dispose of TRU tank sludges
Vitrification Stream Physical and Rheological Property Bounding Conditions
under Contract 24590-101-TSA-W000-0000
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Preparation and Characterization of Chemical Plugs Based on Selected Hanford Waste Simulants
This report presents the results of preparation and characterization of chemical plugs based on selected Hanford Site waste simulants. Included are the results of chemical plug bench testing conducted in support of the M1/M6 Flow Loop Chemical Plugging/Unplugging Test (TP-RPP-WTP-495 Rev A). These results support the proposed plug simulants for the chemical plugging/ unplugging tests. Based on the available simulant data, a set of simulants was identified that would likely result in chemical plugs. The three types of chemical plugs that were generated and tested in this task consisted of: 1. Aluminum hydroxide (NAH), 2. Sodium aluminosilicate (NAS), and 3. Sodium aluminum phosphate (NAP). While both solvents, namely 2 molar (2 M) nitric acid (HNO3) and 2 M sodium hydroxide (NaOH) at 60°C, used in these tests were effective in dissolving the chemical plugs, the 2 M nitric acid was significantly more effective in dissolving the NAH and NAS plugs. The caustic was only slightly more effecting at dissolving the NAP plug. In the bench-scale dissolution tests, hot (60°C) 2 M nitric acid was the most effective solvent in that it completely dissolved both NAH and NAS chemical plugs much faster (1.5 – 2 x) than 2 M sodium hydroxide. So unless there are operational benefits for the use of caustic verses nitric acid, 2 M nitric acid heated to 60°C C should be the solvent of choice for dissolving these chemical plugs. Flow-loop testing was planned to identify a combination of parameters such as pressure, flush solution, composition, and temperature that would effectively dissolve and flush each type of chemical plug from preformed chemical plugs in 3-inch-diameter and 4-feet-long pipe sections. However, based on a review of the results of the bench-top tests and technical discussions, the Waste Treatment Plant (WTP) Research and Technology (R&T), Engineering and Mechanical Systems (EMS), and Operations concluded that flow-loop testing of the chemically plugged pipe sections would not provide any additional information or useful data. The decision was communicated through a Sub Contract Change Notice (SCN-070) that included a revised scope as follows: • Photographing the chemical plugs in the pipes before extrusion to compare the morphology of aged gels with that of fresh gels. • Setting up an extrusion apparatus and extruding the chemical plugs. • Documenting the qualitative observations on the efforts to remove the chemical plug materials from the pipe sections. • Performing X-ray diffraction (XRD) analysis of extruded gel samples to detect any crystallization of gel during storage. • Disposing of the extruded gel as a waste. • Documenting the analytical results in a test report. There were no significant morphological differences between the fresh and aged plugs except for an overgrowth of small transparent crystals on the surface of the aged NAS gel plug. An initial pressure of <150 psi was required to start extruding the aged NAS and NAP plugs, whereas the NAH plug began to extrude with the application of minimal pressure. The shear strength of extruded samples ranged from ~9 to >15 KPa for the NAS plug and from ~2 to 6 KPa for the NAH plug. Following extrusion, the NAP plug sections were thixotropic. The bulk of all the aged gel plugs consisted of amorphous material with nitratine constituting the crystalline phase. A separate question about the whether the current in-tank waste conditions will bound the future multi-tank blended feed conditions for the Waste Treatment Plant is outside the scope of this study
Managerial challenges of Industry 4.0: an empirically backed research agenda for a nascent field
The increasing intelligence of products and systems, their intra-company cross-linking and their cross-company integration into value creation networks is referred to as Industry 4.0. Academics and practitioners, largely agreeing on the global importance of this proclaimed industrial revolution, have published many contributions on the topic. Research, however, is rather focused on investigating single technologies in quite specific application domains and largely neglects the profound managerial challenges underlying Industry 4.0. Given the recent plea for a more active contribution from the management science community, we strive to establish Industry 4.0 as a challenging but promising field for management research, and aim to assist scholars in engaging with the topic. Therefore, we first gather and analyze extant contributions by means of a systematic literature review and synthesize the information gained into 18 managerial challenges of Industry 4.0 falling into six interrelated clusters: (1) strategy and analysis, (2) planning and implementation, (3) cooperation and networks, (4) business models, (5) human resources and (6) change and leadership. Considering that Industry 4.0 is still an emerging topic and publications may therefore not always be found in highly ranked journals, we aimed to increase the confidence in our findings and triangulated our data by conducting an online survey of industry experts and academics that allows us to qualify the identified challenges in terms of importance and future research need. On this basis, we present an empirically backed research agenda and suggest fruitful avenues for future research in three basic categories: practice-enhancing research, knowledge-enhancing research, and high-impact research