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Groenewold, Gary S.

Publications and source records attributed to Groenewold, Gary S..

Gamma Radiolysis of Phenyl-Substituted TODGAs: Part I

The radiolytic stabilities of three phenylated analogs of N,N,N’,N’-tetraoctyl diglycolamide (TODGA) were investigated: 2-(2-(di-n-octylamino)-2-oxoethoxy)-N,N-di-n-octyl-2-phenylacetamide (PhTODGA), which has a phenyl substituent bound to a central methylene, 2-(2-(di-n-octylamino)-2-oxo-1-phenylethoxy)-N,N-di-n-octylpropanamide (PhMeTODGA), which also contains a methyl substituent bound to the methylene on the other side of the ether moiety, and, 2-(2-N-n-hexyl-N-phenylamino)-2-oxoethoxy)-N-n-hexyl-N-phenylacetamide (DHDPDGA), which has phenyl substituents located on the amide groups instead of the central methylenes. The objective of Part I of this series of papers covers was to evaluate the contribution of the phenyl group to the radiolytic stability of these diglycolamides when irradiated in a) n-dodecane, and b) n-dodecane in the presence of a nitric acid-containing aqueous phase. The results indicate that the presence of the phenyl group decreases the overall radiolytic stability compared to unsubstituted TODGA. However, the results also indicate that the phenyl groups interact with nitric acid in a cooperative fashion that enhances the radiation stability of the phenylated diglycolamide (DGA) derivatives in the presence of a nitric acid-containing aqueous phase compared to irradiation in only n-dodecane. So, the results are consistent with the hypothesized formation of nitric acid-phenylated DGA complexes in the n-dodecane phase that are significantly more stable with respect to gamma irradiation, compared to the phenylated DGA molecules alone.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Gamma Radiolysis of Phenyl-Substituted TODGAs: Part II

The radiolytic degradation chemistry of three phenylated analogs of $N,N,N’,N’$-tetraoctyl diglycolamide (TODGA) was investigated: 2-(2-(di-$n$-octylamino)-2-oxoethoxy)-$N,N$-di-$n$-octyl-2-phenylacetamide (PhTODGA), which has a phenyl substituent bound to a central methylene, 2-(2-(di-$n$-octylamino)-2-oxo-1-phenylethoxy)-$N,N$-di-$n$-octylpropanamide (PhMeTODGA), which also contains a methyl substituent bound to the methylene on the other side of the ether moiety, and, 2-(2-$N$-$n$-hexyl-$N$-phenylamino)-2-oxoethoxy)-$N$-$n$-hexyl-$N$-phenylacetamide (DHDPDGA), which has phenyl substituents located on the amide groups instead of the central methylenes. In Part II of this series of papers radiolytic degradation products were identified after separation with liquid chromatography by High Resolution, Accurate-Mass mass spectrometry and collision-induced dissociation. At least twenty-two radiolytic degradation products were identified for PhTODGA, twenty-nine for PhMeTODGA, and over three dozen for DHDPDGA. The suite of radiolytic degradation products of these three investigated ligands was significantly larger than has been reported for previously studied diglycolamides, owing to their asymmetric nature, and to the identification of several new degradation mechanisms, including addition of methyl, hydroxyl, and nitrogen oxide radicals, that have not been previously reported for diglycolamides. Degradation products that contained addition of a NO 2 or NO 3 group were particularly prevalent for DHDPDGA, likely due to the phenyl side-groups. In conclusion, several of these newly observed mechanisms do not appear to depend on the presence of the phenyl groups, suggesting these novel mechanisms may apply to other diglycolamides.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Materials Challenges and Opportunities for Energy Generation, Conversion, Delivery, and Storage (Applied Energy Tri-Laboratory Consortium Workshop Report)

This report documents the outcomes of the Tri-Laboratory Materials Workshop that was held July 31 and August 1, 2019 to begin addressing the needs, opportunities, and challenges associated with the development, fabrication, and testing of the needed materials and components for integrated hybrid energy systems (i.e., incorporating nuclear, fossil, and renewables for electric and thermal applications). This was accomplished by assembling the research program leads and principal investigators at Idaho National Laboratory (INL), National Energy Technology Laboratory (NETL), and National Renewable Energy Laboratory (NREL), who support the research and development of new technology and system integration. The team then identified and prioritized key materials development needs. This effort was intended to enhance communications and synergy among the Tri-Lab partners. Advanced functional and structural materials are central to transformative energy technologies for energy generation, conversion, delivery, and storage. With that in mind, the workshop focused on identifying and assessing the foundational materials research needs at both the basic and applied levels. Materials challenges include the ability to withstand harsh environments, such as high temperatures and pressures, corrosion, oxidation, or irradiation while maintaining flexible mission profiles and long service lifespans. Advanced energy system material challenges and needs range from materials for the capture, upgrading/concentration, storage, and delivery of low-grade heat to materials for high temperature environments that involve liquid metals, molten salt, and very high temperature gas heat delivery and storage systems. Material improvements are needed for hybrid energy systems due to accelerated corrosion and stress-fatigue failure of materials and equipment, which results from increased frequency and amplitude of thermal, mechanical, and electrical cycling of systems components. Multifunctional materials are needed for high temperature solid-oxide fuel cells, advanced electrochemical reactors, and in-process separation. Relative to materials manufacturing, application of advanced additive and subtractive methods need to be understood to develop both thin-layer homogenous materials and materials of graded composition. Materials modeling and machine learning will be critical to accelerate the design and production of power electronics, and nuclear reactor materials and fuel, as well as to gain an understanding of beneficial materials phenomena or deleterious microstructure evolution. There is also a need for standardized models, computational structures, data reporting protocols and modeling tools across the three laboratories. This would allow consistent results, analysis, and data sharing. Combining computational capabilities between the three laboratories (e.g., hardware, software) would greatly increase computational capabilities and throughput. The workshop identified the need for laboratories to anticipate and address problems that will occur during scale-up. Laboratory work must connect with industry to ensure that research focuses on processes that are scalable and marketable. Industry input and perspective are essential to guide laboratory research to meet these requirements and deploy new technology in industrial demonstrations. Another aspect of scale-up is the integration of multiple systems since new challenges often arise at the subsystem interfaces. Establishing a scale-up manufacturing demonstration/pilot plant, potentially as an industrial user facility, would be beneficial to the laboratories and industry. That modular scale-up manufacturing demonstration/pilot plant would allow researchers to find and resolve interface problems that cannot be identified by focusing only on individual parts. Communication exchanges among the organizers, attendees, and workshop survey responses indicate that the workshop was successful in achieving its goal to identify key technology gaps and research needs. Strong positive feedback was received on the sharing of ideas, capabilities, talent, and passion to move forward on the materials-related action items.

36 MATERIALS SCIENCE↗