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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Development Of High Waste-Loading HLW Glasses For High Bismuth Phosphate Wastes

This report presents results from tests with new glass formulations that have been developed for several high Bi-P HLW compositions that are expected to be processed at the WTP that have not been tested previously. WTP HLW feed compositions were reviewed to select waste batches that are high in Bi-P and that are reasonably distinct from the Bi-limited waste that has been tested previously. Three such high Bi-P HLW compositions were selected for this work. The focus of the present work was to determine whether the same type of issues as seen in previous work with high-Bi HLW will be seen in HLW with different concentrations of Bi, P and Cr and also whether similar glass formulation development approaches would be successful in mitigating these issues. New glass compositions were developed for each of the three representative Bi-P HLW wastes and characterized with respect to key processing and product quality properties and, in particular, those relating to crystallization and foaming tendency.

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DOE OSTI2017

Mixed Metal Phosphonate- Phosphate Resins for Separation of Lanthanides from Actinides

As indicated in the previous annual report the goals of this project are to develop procedures for efficient separation of lanthanides from actinides and curium from americium. These processes are required for the nuclear fuel cycle to minimize the waste and recover the valuable actinides. The basis for our study is that we have prepared a group of compounds that are porous and favor the uptake of ions with charges 3+ and 4+ over ions of lesser charge. The general formula for these materials is M(O 3 PC 6 H 4 PO 3 ) 1-x/2 (APO 4 )x·nH 2 O: where M=Zr 4+ , Sn 4+ , A=H, Na, or K and X=O, 0.5, 0.8, 1.0, 1.33 and 1.61-3. One of our tasks is to determine which members of this group of compounds are effective in carrying out the required separations. A difficulty in obtaining this required information is that the compounds are amorphous. That is they are not crystalline, therefore we need to resort to synchrotron data to obtain structural data which will be presented in detail. This information will be provided as a separate section.

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DOE OSTI2018

Gaseous Diffusion Membrane Leaching with Select Lixiviants: Ammonium Carbonate, Sodium Phosphate and Ammonium thiosulfate

As part of ongoing efforts by the Department of Energy’s Portsmouth/Paducah Project Office to decommission the uranium enrichment gaseous diffusion plant at Paducah, KY, research efforts have been focused on removing the remaining kilogram quantities of technetium-99 (Tc-99) from the facility diffusion cascades to meet Tc-99 Waste Acceptance Criteria (WAC) disposal requirements for decommissioning waste.

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DOE OSTI2021

Life Cycle Inventories for Palladium on Niobium Phosphate (Pd/NbOPO 4 ) and Zirconium Oxide (ZrO 2 ) Catalysts

We report the cradle-to-gate GHG emissions, fossil fuel consumption, and water consumption for Nb 2 O 5 , KNbO 3 , NbOPO 4 , Pd, Pd/NbOPO 4 , ZrSiO 4 , and ZrO 2 . Notably, the net GHG emissions impact of the Pd/NbOPO 4 catalyst is 8.5 kg CO 2 e/kg catalyst, which is comparable to other catalysts in GREET, while the net GHG emissions of the ZrO 2 catalyst is considerably lower at 1.8 kg CO 2 e/kg catalyst. We also identify the primary contributors to each catalyst’s cradle-to-gate environmental burden. For the Pd/NbOPO 4 catalyst, Pd metal is the main driver of GHG emissions and fossil fuel consumption, while Pd and NbOPO 4 contribute almost equally to water consumption. For the ZrO 2 catalyst, sodium hydroxide (NaOH) is the principal driver of GHG emissions and fossil fuel consumption, while ZrSiO 4 is the main consumer of water. The Pd/NbOPO 4 and ZrO 2 catalysts, as well as Nb 2 O 5 , KNbO 3 , NbOPO 4 , and ZrSiO 4 , are implemented in the GREET catalyst module, and Pd has been implemented in GREET2 (Kingsbury and Benavides 2021). The material and energy flows for these new materials will be useful to future LCAs, particularly those involving biofuel production.

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DOE OSTI2023

Direct Extraction of Lanthanide Oxides and Nitrates in Tributyl Phosphate

This work investigated the dissolution rate of lanthanide oxides and nitrates in a 30 vol % TBP-n-paraffin solvent (pre-equilibrated with various nitric acid concentrations) using visible (Vis) spectroscopy over time. Some dissolution mechanics were observed, such as an aqueous layer forming, considerably longer dissolution times for the heavier lanthanides (hours) vs. the lighter lanthanides (minutes), and the impacts of mixing lanthanide oxides or nitrates during dissolution. Neodymium, samarium, holmium, and erbium were selected due to their unique spectroscopic signatures and to represent the lighter (neodymium and samarium) and heavier (holmium and erbium) lanthanides. Even though europium does not have a strong absorbance in the range studied, europium was used in some instances to also represent the lighter lanthanides. Cerium oxide was used to representant dissolution of tetravalent lanthanides.

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DOE OSTI2025

Vitrification Testing of HLW with High Phosphate

Projections of the number of high level waste (HLW) canisters to be produced in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) (e.g., [1]) are based upon the inventory of the tank wastes, the anticipated performance of the sludge treatment processes, and current understanding of the capability of the borosilicate glass waste form. The WTP HLW melter design, unlike earlier Department of Energy (DOE) melter designs, incorporates a glass bubbler system. The bubblers create active glass pool mixing and thereby improve heat and mass transfer and glass melting rate. The WTP HLW melters each have a glass surface area of 3.75 m 2 and depth of ~1.1 m. The two melters in the HLW facility together are designed to produce up to 7.5 MT of glass per day at 100% availability. Further increases in HLW waste processing rates can potentially be achieved by optimization of the feed and glass formulations, increasing the melter operating temperature above 1150⁰C, and by increasing the waste loading in the glass product. Increasing the waste loading also has the added benefit of decreasing the number of canisters for storage.

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