DISCLAIMERPortions of this document m y be illegible in electronic image products. Images are produced from the best available original document. Executive SummaryWastes stored in Hanford Tank 241-SY-10 are planned to be retrieved from the tank and transferred to 200 East Area through the new pipeline Replacement Cross Site Transfer System (RCSTS). This report describes results of the second phase (the detailed assessment) of a the SY-102 waste retrieval study, which is a part of the efforts to establish a technical basis for mobilization of the slurry, waste retrieval, and slurry transport. This second-phase study was performed to close uncertainty issues on Tank SY-102 waste retrieval identified under the previous preliminary assessment (Onishi and Hudson 1996). The uncertainties on the preliminary assessment were primariiy related to lack of data on waste characteristics and the assumption of the tank being fully mixed. To resolve these issues, this Phase 11 study 1) identified solid phases of the SY-102 waste by using transmission electron microscopy (TEMJ, 2) conducted laboratory experiments to measure rheology, zeta potential to evaluate solid agglomeration, and sedimentation, 3) measured particle size distributions of the wastes, and 4) simulated time-varying, three-dimensional, tank pump jet mixing.The Phase 11 study results confirms the validity of the assumptions and parameter selections used in the preliminary assessment (Onishi and Hudson 1996) and supports its conclusion that the SY-102 waste m i h g and heating do not adversely impact the waste retrieval operation. . Specific conclusions of this study are briefly summarized below.The Transmission Electron Microscopy results show that the morphology of the agglomerates is dominated by large size (2-5 pm x 10-30 pm) NaOH rods s~o u n d e d by finer primary particles of various materials. A large population of amorphous silica and iron hydroxide primary particles in the nanometer size range was' observed. Also, needle-like FeO(0H) agglomerates and sharp-edged plate-like y-A1203 particles were found. Irregt&x U-containing agglomerates and rectangular MCrcontaining particles were also present. The major 'crystalline phases observed include: micrometersized y-Al2O3, needle-like FeO(0H) and Al2Si4010. The minor crystalline phases observed were rodlike particles of hydroxylapatite, Cas(PO)3(OH) and single crystalline gibbsite, Al(OH)3. t rod-like particles of hydroxylapatite, Ca5(PO)3(OH) and single crystalline gibbsite, Al(Orn.3. The preliminary assessment study (Onishi and Hudson 1996) assumed the all Al solids to be gibbsite for the chemical reaction modeling. The current TEM identified Al solids to be y-Al2O3, Al$34010, and gibbsite.Gibbsite and y-A1203 are chemically similar. Moreover, existence of y-Al2O3 would slightly increase the amount of water in the solution, as compared with gibbsite. Moreover, since the sludge has a much smaller amount of Si than the amount of Al, the majority of Al is not expected to form a solid with Si. Thus, the prelimina...
Much attention has been paid in recent years to the use of nanoparticle suspensions for enhanced heat transfer. The majority of this work has focused on the thermal conductivity of these nanofluids, which can be as much as 2.5 times higher than that of the plain base fluid. The present work moves beyond measurements of non-flowing liquids, to explore the role that nanofluids can play in enhancing convective heat transfer within microscale channels. A unique pseudo-turbulent flow regime is postulated, which simulates turbulent behavior at very low Reynolds numbers, in what are nominally laminar flows. The resulting fluid mixing has the potential to raise the average convective heat transfer coefficient within the channel. Numerical modeling, using the lattice Boltzmann method, confirms the existence of the pseudo-turbulent flow regime. Finally, experimental results are presented which demonstrate a significant heat transfer enhancement when using nanofluids in forced convection. The current results are especially relevant to microchannel heatsinks, where the low Reynolds numbers impose limitations on the maximum Nusselt number achievable.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.