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At least 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Variants of Regenerated Fissile Materials Usage in Thermal Reactors as the First Stage of Fuel Cycle Closing

At present, 240 000 t of spent nuclear fuel (SF) has been accumulated in the world. Its long-term storage should meet safety conditions and requires noticeable finances, which grow every year. Obviously, this situation cannot exist for a long time; in the end, it will require a final decision. At present, several variants of solution of the problem of SF management are considered. Since most of the operating reactors and those under construction are thermal reactors, it is reasonable to assume that the structure of the nuclear power industry in the near and medium-term future will be unchanged, and it will be necessary to utilize plutonium in thermal reactors. In this study, different strategies of SF management are compared: open fuel cycle with long-term SF storage, closed fuel cycle with MOX fuel usage in thermal reactors and subsequent long-term storage of SF from MOX fuel, and closed fuel cycle in thermal reactors with heterogeneous fuel arrangement. The concept of heterogeneous fuel arrangement is considered in detail. While in the case of traditional fuel it is necessary to reprocess the whole amount of spent fuel, in the case of heterogeneous arrangement, it is possible to separate plutonium and {sup 238}U in different fuel rods. In this case, it is possible to achieve nearly complete burning of fissile isotopes of plutonium in fuel rods loaded with plutonium. These fuel rods with burned plutonium can be buried after cooling without reprocessing. They would contain just several percent of initially loaded plutonium, mainly even isotopes. Fuel rods with {sup 238}U alone should be reprocessed in the usual way.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2012

Regeneration of Tissues and Organs Using Autologous Cells

The proposed work aims to address three major challenges to the field of regenerative medicine: 1) the growth and expansion of regenerative cells outside the body in controlled in vitro environments, 2) supportive vascular supply for large tissue engineered constructs, and 3) interactive biomaterials that can orchestrate tissue development in vivo. Toward this goal, we have engaged a team of scientists with expertise in cell and molecular biology, physiology, biomaterials, controlled release, nanomaterials, tissue engineering, bioengineering, and clinical medicine to address all three challenges. This combination of resources, combined with the vast infrastructure of the WFIRM, have brought to bear on projects to discover and test new sources of autologous cells that can be used therapeutically, novel methods to improve vascular support for engineered tissues in vivo, and to develop intelligent biomaterials and bioreactor systems that interact favorably with stem and progenitor cells to drive tissue maturation. The Institute's ongoing programs are aimed at developing regenerative medicine technologies that employ a patient's own cells to help restore or replace tissue and organ function. This DOE program has provided a means to solve some of the vexing problems that are germane to many tissue engineering applications, regardless of tissue type or target disease. By providing new methods that are the underpinning of tissue engineering, this program facilitated advances that can be applied to conditions including heart disease, diabetes, renal failure, nerve damage, vascular disease, and cancer, to name a few. These types of conditions affect millions of Americans at a cost of more than $400 billion annually. Regenerative medicine holds the promise of harnessing the body's own power to heal itself. By addressing the fundamental challenges of this field in a comprehensive and focused fashion, this DOE program has opened new opportunities to treat conditions where other approaches have failed.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Chemical Hydrogen Storage using Ultra-High Surface Area Main Group Materials & The Development of Efficient Amine-Borane Regeneration Cycles (Final Report)

The focus of the project was to design and synthesize light element compounds and nanomaterials that will reversibly store molecular hydrogen for hydrogen storage materials. The primary targets investigated during the last year were amine and hydrogen terminated silicon (Si) nanoparticles, Si alloyed with lighter elements (carbon (C) and boron (B)) and boron nanoparticles. The large surface area of nanoparticles should facilitate a favorable weight to volume ratio, while the low molecular weight elements such as B, nitrogen (N), and Si exist in a variety of inexpensive and readily available precursors. Furthermore, small NPs of Si are nontoxic and non-corrosive. Insights gained from these studies will be applied toward the design and synthesis of hydrogen storage materials that meet the DOE 2010 hydrogen storage targets: cost, hydrogen capacity and reversibility. Two primary routes were explored for the production of nanoparticles smaller than 10 nm in diameter. The first was the reduction of the elemental halides to achieve nanomaterials with chloride surface termination that could subsequently be replaced with amine or hydrogen. The second was the reaction of alkali metal Si or Si alloys with ammonium halides to produce hydrogen capped nanomaterials. These materials were characterized via X-ray powder diffraction, TEM, FTIR, TG/DSC, and NMR spectroscopy.

08 HYDROGEN↗
DOE OSTI2012

A Low Cost, High Capacity Regenerable Sorbent for Pre-combustion CO 2 Capture

The overall objective of the proposed research is to develop a low cost, high capacity CO 2 sorbent and demonstrate its technical and economic viability for pre-combustion CO 2 capture. The specific objectives supporting our research plan were to optimize the chemical structure and physical properties of the sorbent, scale-up its production using high throughput manufacturing equipment and bulk raw materials and then evaluate its performance, first in bench-scale experiments and then in slipstream tests using actual coal-derived synthesis gas. One of the objectives of the laboratory-scale evaluations was to demonstrate the life and durability of the sorbent for over 10,000 cycles and to assess the impact of contaminants (such as sulfur) on its performance. In the field tests, our objective was to demonstrate the operation of the sorbent using actual coal-derived synthesis gas streams generated by air-blown and oxygen-blown commercial and pilot-scale coal gasifiers (the CO 2 partial pressure in these gas streams is significantly different, which directly impacts the operating conditions hence the performance of the sorbent). To support the field demonstration work, TDA collaborated with Phillips 66 and Southern Company to carry out two separate field tests using actual coal-derived synthesis gas at the Wabash River IGCC Power Plant in Terre Haute, IN and the National Carbon Capture Center (NCCC) in Wilsonville, AL. In collaboration with the University of California, Irvine (UCI), a detailed engineering and economic analysis for the new CO 2 capture system was also proposed to be carried out using Aspen Plus™ simulation software, and estimate its effect on the plant efficiency.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2011

Production and Testing of Microchannel Magnetocaloric Regenerators

Prepared ~1.1 kg of CoMn{sub 1{+-}x}Ge{sub 0.95{+-}y}Sn{sub 0.05{+-}z} (x=0, 0.01, 0.02, 0.04, y=0, 0.005, 0.01, 0.03, z=0, 0.005, 0.01, 0.03) samples by using arc melting and induction melting techniques. The Curie temperatures of the majority of the samples are near the room temperature with a deviation of {+-}20K. Prepared ~4.5 kg of Gd with the dimensions and in the shape required by MER. Characterized CoMn{sub 1{+-}x}Ge{sub {0.95{+-}y}Sn{sub 0.05{+-}z} (x=0,0.01, 0.02, 0.04, y=0, 0.005, 0.01, 0.03, z=0, 0.005, 0.01, 0.03) samples prepared by arc melting, induction melting, and hot pressing techniques. The characterization techniques include powder x-ray diffraction, magnetometry, calorimetry, and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS).

36 MATERIALS SCIENCE↗
DOE OSTI2016

Low Cost, High Capacity Regenerable Sorbent for Carbon Dioxide Capture from Existing Coal-fired Power Plants

In this project TDA Research, Inc (TDA) has developed a new post combustion carbon capture technology based on a vacuum swing adsorption system that uses a steam purge and demonstrated its technical feasibility and economic viability in laboratory-scale tests and tests in actual coal derived flue gas. TDA uses an advanced physical adsorbent to selectively remove CO 2 from the flue gas. The sorbent exhibits a much higher affinity for CO 2 than N 2 , H 2 O or O 2 , enabling effective CO 2 separation from the flue gas. We also carried out a detailed process design and analysis of the new system as part of both sub-critical and super-critical pulverized coal fired power plants. The new technology uses a low cost, high capacity adsorbent that selectively removes CO 2 in the presence of moisture at the flue gas temperature without a need for significant cooling of the flue gas or moisture removal. The sorbent is based on a TDA proprietary mesoporous carbon that consists of surface functionalized groups that remove CO 2 via physical adsorption. The high surface area and favorable porosity of the sorbent also provides a unique platform to introduce additional functionality, such as active groups to remove trace metals (e.g., Hg, As). In collaboration with the Advanced Power and Energy Program of the University of California, Irvine (UCI), TDA developed system simulation models using Aspen PlusTM simulation software to assess the economic viability of TDA’s VSA-based post-combustion carbon capture technology. The levelized cost of electricity including the TS&M costs for CO 2 is calculated as $116.71/MWh and $113.76/MWh for TDA system integrated with sub-critical and super-critical pulverized coal fired power plants; much lower than the $153.03/MWhand $147.44/MWh calculated for the corresponding amine based systems. The cost of CO 2 captured for TDA’s VSA based system is $38.90 and $39.71 per tonne compared to $65.46 and $66.56 per tonne for amine based system on 2011 $ basis, providing 40% lower cost of CO 2 captured. In this analysis we have used a sorbent life of 4 years. If a longer sorbent life can be maintained (which is not unreasonable for fixed bed commercial PSA systems), this would lower the cost of CO 2 captured by $0.05 per tonne (e.g., to $38.85 and $39.66 per tonne at 5 years sorbent replacement). These system analysis results suggest that TDA’s VSA-based post-combustion capture technology can substantially improve the power plant’s thermal performance while achieving near zero emissions, including greater than 90% carbon capture. The higher net plant efficiency and lower capital and operating costs results in a substantial reduction in the cost of carbon capture and cost of electricity for the power plant equipped with TDA’s technology.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2019

Warming-Induced Biome Change at the Temperate-Boreal Ecotone: An Experimental Test of Key Regeneration Processes (Final Technical Report)

This project advanced our understanding of plants’ key physiological and ecological processes that are essential to the survival, success, and carbon cycling of plants from the boreal-temperate forest ecotone in the future climate. A primary goal of the project was to test the effect of warming and water limitation on plants from the Boreal-Temperate Ecotone using a realistic outdoor long-term experiment. Plant at this ecotone is predicted to be particularly sensitive to future climate since the ecotone represents a relatively sharp boundary between many temperate species to the south and boreal species to the north. This work was important, as there was and still is a significant uncertainty surrounding the mechanisms of future climate effects on vegetation compositional and carbon cycling change, especially in forests mostly due to lack of experimental examination of response to warming and limited water availability. Consequently, we tested our central objective, that was to assess the potential for projected climate to alter tree species composition and carbon cycling at the southern boreal-temperate forest ecotone by experimentally warming forest plots and documenting effects on establishment and juvenile performance for tree species near their warmer (boreal species) and colder (temperate species) range limits in northern Minnesota. To accomplish our goals, we designed and built a successful highly manipulative experiment that implemented vegetation-soil warming and rainfall removal in both understory and open habitats at two sites in northern Minnesota (MN). The sites lie at different distances to the north of the ecotone between the southern boreal and northern temperate forest biomes. We focused on ten target species, all of which are near their warmer (Pinus banksiana, Picea glauca, Abies balsamea, Populus tremuloides, Betula papyrifera) or colder (Pinus strobus, Quercus macrocarpa, Quercus rubra, Acer rubrum, Acer saccharum) range edge in northern MN; we also studied other species such as a woody invader and native herbs and shrubs. Three temperature treatments (ambient, +1.7°C, +3.4°C) were imposed using infra-red heating lamps augmented with soil heating cables to simultaneously control soil and vegetation temperatures, enabling assessment of non-linear responses. These temperatures bracket the range of anticipated warming in the region during the next 75-100 years. In addition, we implemented summer rain removal treatment mimicking predicted distribution in precipitation patterns by future climate where we actively removed ~40% of rainfall. Measurements included germinant establishment, plant growth, phenology, physiology and survival, soil, plant and air temperature, soil moisture and nutrient status. These measures enabled us to assess how germination, growth and survival at the establishment stage are influenced by direct climate effects and/or indirect effects of warming, soil resources such as water and nutrients availability or other environmental variables that either directly or indirectly influence plant performance.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Customization for Current Market Applications of the Carbon Nanotubes Produced by PNNL’s Regenerable Catalytic Pyrolysis (ReCaP) for Scaled Hydrogen Production

Here, we demonstrated the Regenerative Catalytic Pyrolysis (ReCaP) process that generates carbon dioxide-free hydrogen (CO 2 -free H 2 ) from inexpensive and domestically abundant natural gas (NG), while simultaneously producing H 2 at net production cost of $1.0/kg through the sale of valuable carbon nanotube (CNT) co-product. The specific goal of this project is to 1) scale up the production of CNT, 2) correlate the properties of the CNT with the reaction conditions, 3) perform a techno-economic analysis to obtain minimum selling price of H 2 and CNT, and 4) identify industrial partners interested in the CNT co-product.

03 NATURAL GAS↗
DOE OSTI2025

Scalable and Regenerable Fibrous Amine-functionalized Matrix (FAM) sorbent for Efficient Enrichment of Critical Minerals from Coal Wastewaters

The poster presents the latest progress on utilizing a commercially scalable flat sheet sorbent for the effective enrichment of critical minerals from coal wastewater. It highlights the performance, scalability, and potential for industrial applications, addressing key challenges in critical recovery from complex wastewater streams.

critical metals↗
DOE OSTI2025

Considerations for the Development of a Regenerable LANA.75 Bed for Tritium Storage

LaNi4.25Al0.75 or LANA.75 has been used by the Savannah River Site Tritium Facilities for decades to safely store hydrogen isotopes • High molar density at moderate pressures (~1000x that of gas at STP) = less glovebox space • Can be used as a pump by varying temperature = fewer moving parts • Can deliver He-3 free gas = fewer unit operations • Beds are limited life components due to accumulation of He-3 • Formation of “heel” • Inventory hold-up • Reduced capacity • Eventual weeping of He-3

STAACK, Gregory [Savannah River National Laborator↗
DOE OSTI2018

Liquid Crystal Elastomers—A Path to Biocompatible and Biodegradable 3D-LCE Scaffolds for Tissue Regeneration

The development of appropriate materials that can make breakthroughs in tissue engineering has long been pursued by the scientific community. Several types of material have been long tested and re-designed for this purpose. At the same time, liquid crystals (LCs) have captivated the scientific community since their discovery in 1888 and soon after were thought to be, in combination with polymers, artificial muscles. Within the past decade liquid crystal elastomers (LCE) have been attracting increasing interest for their use as smart advanced materials for biological applications. Here, we examine how LCEs can potentially be used as dynamic substrates for culturing cells, moving away from the classical two-dimensional cell-culture nature. We also briefly discuss the integration of a few technologies for the preparation of more sophisticated LCE-composite scaffolds for more dynamic biomaterials. The anisotropic properties of LCEs can be used not only to promote cell attachment and the proliferation of cells, but also to promote cell alignment under LCE-stimulated deformation. 3D LCEs are ideal materials for new insights to simulate and study the development of tissues and the complex interplay between cells.

36 MATERIALS SCIENCE↗