Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Waste Forms”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Metal-Organic Framework Glasses as Rad Contaminant Sequesters and Nuclear Waste Forms

Remediation of Tc remains an unresolved problem at SRS and other DOE sites. The objective of this project was to develop novel metal organic framework (MOF) glasses for radioactive contaminant sequestration and stabilization from aqueous media. During FY20, we synthesized, characterized and evaluated additional cetyltrimethylcimmonium bromide (CTAB)-functionalized and F - , Cl - , I - , CF 3 SO 3 - exchanged MIL-101-Cr samples. MIL-10l-Cr-NO 3 -CTAB was demonstrated to have high ReO 4 - removed capacity (139 mg/g sorbent) from artificial groundwater (AGW). Re chemical specicition and binding mechanism on MIL-101-CTAB were also studied by synchrotron X-ray absorption spectroscopy. ReO 4 - was demonstrated as being in the pore structure with slightly larger Re-O bond distances than those in NciReO 4 and binding with the positively charged sites of CTAB. In addition, a new Ni-TIPA MOF was demonstrated to be very stable, selective and effective for TcO 4 - removed from the SRS tank waste stream (~90% removed). The Ni-TIPA MOF sample containing ReO 4 - was prepared and shipped/planned for vitrification studies by a high-pressure technique. This research may provide a highly applicable platform for solving critical DOE and industrial problems related to nuclear environmental stewardship and nuclear power production.

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

Metal-Organic-Framework Glasses as Rad Contaminant Sequesters and Nuclear Waste Forms

Remediation of Tc remains an unresolved challenge at SRS and other DOE sites. The objective of this project was to develop novel metal organic framework (MOF) glasses for radioactive contaminant sequestration and stabilization from aqueous media. We synthesized, characterized and evaluated ten MOFs of known crystal structure and chemistry for screening MOFs for TcO 4 - and ReO 4 - sequestration. MIL-101(Cr) was most effective for TcO 4 - and ReO 4 - sequestration from artificial groundwater at equilibration pH values with the removal capacity of 0.076 mg/g for Tc and 0.197 mg/g for Re. MIL-101(Fe), SLUG-22 and UiO- 66- NO 2 were moderately effective under similar conditions (pH < 8). These results established a solid foundation for further development of MIL-101(Cr) and new MOFs to increase TcO 4 - removal capacity and improve MOF structural stability in FY19.This research may provide a highly applicable platform for solving critical DOE and industrial problems related to nuclear environmental stewardship and nuclear power production.

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

Metal-Organic-Framework Glasses as Rad Contaminant Sequesters and Nuclear Waste Forms

Remediation of Tc remains an unresolved challenge at SRS and other DOE sites. The objective of this project was to develop novel metal organic framework (MOF) glasses for radioactive contaminant sequestration and stabilization from aqueous media. We synthesized, characterized and evaluated ten MOFs of known crystal structure and chemistry for screening MOFs for TcO 4 - and ReO 4 - sequestration. MIL-101(Cr) was most effective for TcO 4 - and ReO 4 - sequestration from artificial groundwater at equilibration pH values with the removal capacity of 0.076 mg/g for Tc and 0.197 mg/g for Re. MIL-101(Fe), SLUG-22 and UiO-66-NO 2 were moderately effective under similar conditions (pH < 8). These results established a solid foundation for further development of MIL-101(Cr) and new MOFs to increase TcO 4 - removal capacity and improve MOF structural stability in FY19. This research may provide a highly applicable platform for solving critical DOE and industrial problems related to nuclear environmental stewardship and nuclear power production.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Preparation of iodine-bearing waste forms for hot isostatic pressing

Oak Ridge National Laboratory (ORNL) has prepared a new set of iodine-bearing sorbents. The sorbent materials used for this activity were supplied by IONEX (NexSorb-99) or C&CS (AC6120-7%). Metal canisters were previously prepared by ORNL in 2022. They are 2 in. long by 1.5 in. in diameter and are made of 316 stainless steel.

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

Understanding the Stability of Salt-Inclusion Phases for Nuclear Waste-forms through Volume-based Thermodynamics

Abstract Formation enthalpies and Gibbs energies of actinide and rare-earth containing SIMs with silicate and germanate frameworks are reported. Volume-based thermodynamics (VBT) techniques complemented by density functional theory (DFT) were adapted and applied to these complex structures. VBT and DFT results were in closest agreement for the smaller framework silicate structure, whereas DFT in general predicts less negative enthalpies across all SIMs, regardless of framework type. Both methods predict the rare-earth silicates to be the most stable of the comparable structures calculated, with VBT results being in good agreement with the limited experimental values available from drop solution calorimetry.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗