Results for “Waste Forms” — Page 100

DOE OSTI2024

ChemPren: a new and economical technology for conversion of waste plastics to light olefins

With the ever-increasing demand for plastics, sustainable recycling methods are key necessities. Here, the current plastics industry can manage to recycle only 10% of the 400 million metric tons of plastic produced globally. Waste plastics, in the current infrastructure, land up mostly in landfills. Although a lot of research efforts have been spent on processing and recycling co-mingled mixed plastics, energy-efficient sustainable and scalable routes for plastic upcycling are still lacking. Catalytic valorization of waste plastic feedstock is one of the potential scalable routes for plastic upcycling. Silica-alumina based materials, and zeolites have shown a lot of promise. A major interest lies in restricting catalyst deactivation, and refining product selectivity and yield for such catalytic processes. This article highlights ChemPren technology as a clean energy solution to waste plastic recycling. Co-mingled, mixed plastic feedstock along with spray dried, attrition resistant, ZSM-5 containing catalysts is preprocessed with an extruder to form optimally sized particles and fed into a fluidized bed reactor for short contact times to produce selectively and in high yields ethylenes, propylenes and butylenes. This techno-economic perspective indicates that the ChemPren technology can produce propylene at $\$$0.16 per lb, whereas the current selling price of virgin propylene is $0.54 per lb. This technology can serve as a platform for mixed plastic upcycling, with more advancements necessary in the form of robust and resilient catalysts and reactor operation strategies for tuning product selectivity.

25 - ENERGY STORAGE↗

DOE OSTI2013

Analysis Of 2H-Evaporator Scale Pot Bottom Sample [HTF-13-11-28H]

Savannah River Remediation (SRR) is planning to remove a buildup of sodium aluminosilicate scale from the 2H-evaporator pot by loading and soaking the pot with heated 1.5 M nitric acid solution. Sampling and analysis of the scale material from the 2H evaporator has been performed so that the evaporator can be chemically cleaned beginning July of 2013. Historically, since the operation of the Defense Waste Processing Facility (DWPF), silicon in the DWPF recycle stream combines with aluminum in the typical tank farm supernate to form sodium aluminosilicate scale mineral deposits in the 2H-evaporator pot and gravity drain line. The 2H-evaporator scale samples analyzed by Savannah River National Laboratory (SRNL) came from the bottom cone sections of the 2H-evaporator pot. The sample holder from the 2H-evaporator wall was virtually empty and was not included in the analysis.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2016

Technetium recovery from high alkaline solution

Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2015

Materials and fabrication sequences for water soluble silicon integrated circuits at the 90 nm node

Tungsten interconnects in silicon integrated circuits built at the 90 nm node with releasable configurations on silicon on insulator wafers serve as the basis for advanced forms of water-soluble electronics. These physically transient systems have potential uses in applications that range from temporary biomedical implants to zero-waste environmental sensors. Systematic experimental studies and modeling efforts reveal essential aspects of electrical performance in field effect transistors and complementary ring oscillators with as many as 499 stages. Accelerated tests reveal timescales for dissolution of the various constituent materials, including tungsten, silicon, and silicon dioxide. The results demonstrate that silicon complementary metal-oxide-semiconductor circuits formed with tungsten interconnects in foundry-compatible fabrication processes can serve as a path to high performance, mass-produced transient electronic systems.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2019

Fine Calcium Carbonate Production by CO 2 Mineralization of Industrial Waste Brines

Calcium carbonate production via CO 2 mineralization offers an attractive route for carbon capture and utilization. The process sequesters CO 2 in a stable form of fine precipitated calcium carbonate, a high-value product with unit price in the range of $230-$280/t and a global market projected to reach 99 M tons in 2020. However, two critical barriers hinders CO 2 mineralization—(i) the need for costly processes such as electrolysis or addition of alkali hydroxides to maintain alkalinity during mineralization, and (ii) the geographic location mismatch between Ca-rich solutions (or brines) CO 2 generation sources (e.g. power plants) which often renders efficient integration of feedstocks impractical. To simultaneously address these challenges, a new process is developed to integrate CO 2 mineralization-based carbonate production into the zero liquid discharge water (ZLD) treatment systems at coal-fired power plants. In this process, Ca-rich streams, such as produced water from oil and gas extraction or carbon storage operations, serves as the Ca-source. An H + /Na + ion-exchange cycle is designed to provision alkalinity during mineralization and regenerate the ion-exchange reagent in solutions with high salinity. Ca-depleted streams are then treated within a centralized ZLD system. The process beneficially utilizes reject streams that are available at substantial quantities in the vicinity of coal power plants within several U.S regions. In addition, the process utilizes post-desulfurization flue gas from coal-fired power plants as is. The CO 2 conversion reactions are performed in alkaline streams at ambient pressure, thereby minimizing the energy burden. By beneficiation of industrial waste streams with low energy input, this process offers significant technical advantages in energy and CO 2 footprint over the current paradigm of precipitated calcium carbonate production. Overall, the new process provides a unique route to integrate CO 2 emissions control and wastewater treatment for coal power plants, while producing high-value product to offset the economic burden associated with waste management

Simonetti, Dante↗

DOE OSTI2019

Fine Calcium Carbonate Production by CO 2 Mineralization of Industrial Waste Brines

Calcium carbonate production via CO 2 mineralization offers an attractive route for carbon capture and utilization. The process sequesters CO 2 in a stable form of fine precipitated calcium carbonate, a high-value product with unit price in the range of $230-$280/t and a global market projected to reach 99 M tons in 2020. However, two critical barriers hinders CO 2 mineralization—(i) the need for costly processes such as electrolysis or addition of alkali hydroxides to maintain alkalinity during mineralization, and (ii) the geographic location mismatch between Ca-rich solutions (or brines) CO 2 generation sources (e.g. power plants) which often renders efficient integration of feedstocks impractical. To simultaneously address these challenges, a new process is developed to integrate CO 2 mineralization-based carbonate production into the zero liquid discharge water (ZLD) treatment systems at coal-fired power plants. In this process, Ca-rich streams, such as produced water from oil and gas extraction or carbon storage operations, serves as the Ca-source. An H + /Na + ion-exchange cycle is designed to provision alkalinity during mineralization and regenerate the ion-exchange reagent in solutions with high salinity. Ca-depleted streams are then treated within a centralized ZLD system. The process beneficially utilizes reject streams that are available at substantial quantities in the vicinity of coal power plants within several U.S regions. In addition, the process utilizes post-desulfurization flue gas from coal-fired power plants as is. The CO 2 conversion reactions are performed in alkaline streams at ambient pressure, thereby minimizing the energy burden. By beneficiation of industrial waste streams with low energy input, this process offers significant technical advantages in energy and CO 2 footprint over the current paradigm of precipitated calcium carbonate production. Overall, the new process provides a unique route to integrate CO 2 emissions control and wastewater treatment for coal power plants, while producing high-value product to offset the economic burden associated with waste management.

Simonetti, Dante↗

DOE OSTI2019

Fine Calcium Carbonate Production by CO 2 Mineralization of Industrial Waste Brines

Calcium carbonate production via CO 2 mineralization offers an attractive route for carbon capture and utilization. The process sequesters CO 2 in a stable form of fine precipitated calcium carbonate, a high-value product with unit price in the range of $230-$280/t and a global market projected to reach 99 M tons in 2020. However, two critical barriers hinders CO 2 mineralization—(i) the need for costly processes such as electrolysis or addition of alkali hydroxides to maintain alkalinity during mineralization, and (ii) the geographic location mismatch between Ca-rich solutions (or brines) CO 2 generation sources (e.g. power plants) which often renders efficient integration of feedstocks impractical. To simultaneously address these challenges, a new process is developed to integrate CO 2 mineralization-based carbonate production into the zero liquid discharge water (ZLD) treatment systems at coal-fired power plants. In this process, Ca-rich streams, such as produced water from oil and gas extraction or carbon storage operations, serves as the Ca-source. An H + /Na + ion-exchange cycle is designed to provision alkalinity during mineralization and regenerate the ion-exchange reagent in solutions with high salinity. Ca-depleted streams are then treated within a centralized ZLD system. The process beneficially utilizes reject streams that are available at substantial quantities in the vicinity of coal power plants within several U.S regions. In addition, the process utilizes post-desulfurization flue gas from coal-fired power plants as is. The CO 2 conversion reactions are performed in alkaline streams at ambient pressure, thereby minimizing the energy burden. By beneficiation of industrial waste streams with low energy input, this process offers significant technical advantages in energy and CO 2 footprint over the current paradigm of precipitated calcium carbonate production. Overall, the new process provides a unique route to integrate CO 2 emissions control and wastewater treatment for coal power plants, while producing high-value product to offset the economic burden associated with waste management.

Simonetti, Dante↗

DOE OSTI2019

Fine Calcium Carbonate Production by CO 2 Mineralization of Industrial Waste Brines

Calcium carbonate production via CO 2 mineralization offers an attractive route for carbon capture and utilization. The process sequesters CO 2 in a stable form of fine precipitated calcium carbonate, a high-value product with unit price in the range of $230-&dollar;280/t and a global market projected to reach 99 M tons in 2020. However, two critical barriers hinders CO 2 mineralization—(i) the need for costly processes such as electrolysis or addition of alkali hydroxides to maintain alkalinity during mineralization, and (ii) the geographic location mismatch between Ca-rich solutions (or brines) CO 2 generation sources (e.g. power plants) which often renders efficient integration of feedstocks impractical. To simultaneously address these challenges, a new process is developed to integrate CO 2 mineralization-based carbonate production into the zero liquid discharge water (ZLD) treatment systems at coal-fired power plants. In this process, Ca-rich streams, such as produced water from oil and gas extraction or carbon storage operations, serves as the Ca-source. An H + /Na + ion-exchange cycle is designed to provision alkalinity during mineralization and regenerate the ion-exchange reagent in solutions with high salinity. Ca-depleted streams are then treated within a centralized ZLD system. The process beneficially utilizes reject streams that are available at substantial quantities in the vicinity of coal power plants within several U.S regions. In addition, the process utilizes post-desulfurization flue gas from coal-fired power plants as is. The CO 2 conversion reactions are performed in alkaline streams at ambient pressure, thereby minimizing the energy burden. By beneficiation of industrial waste streams with low energy input, this process offers significant technical advantages in energy and CO 2 footprint over the current paradigm of precipitated calcium carbonate production. Overall, the new process provides a unique route to integrate CO 2 emissions control and wastewater treatment for coal power plants, while producing high-value product to offset the economic burden associated with waste management.

Simonetti, Dante↗

DOE OSTI2017

Novel Gamma Attenuation Methods Utilized for Waste Characterization of UO{sub 2}F{sub 2}-Bearing Materials at the Paducah GDP - 17327

The Paducah Gaseous Diffusion Plant (PGDP) is currently under deactivation with demolition in the decades to follow. UO{sub 2}F{sub 2}-bearing waste is generated at PGDP by UF{sub 6} hydrolysing to materials such as pipes, valves, PPE, etc. when UF{sub 6} is exposed to humid air. In addition, Al{sub 2}O{sub 3} and NaF trap materials contain significant amounts of Uranium. The UO{sub 2}F{sub 2} deposits within the generated waste can be of sub-gram levels to several hundreds of localized grams and are much denser than the surrounding interfering matrix materials and may be of very complex geometric and chemical forms such as with the Al{sub 2}O{sub 3} and NaF trap materials. The main objective is to characterize the fissile (U-235) content of the UO{sub 2}F{sub 2}-bearing waste so as to meet the Data Quality Objectives (DQO) for proper disposal. If a waste container cannot meet the DQO then it must be subjected to costly remediation, repackaging and re-characterization processes. We have developed, at PGDP, several novel model-based methods and techniques that vastly improve the standard gamma attenuation correction methods and do not require Working Reference Materials (WRM) for calibration. These new methods involve rotating and non-rotating 18.9 liter (5 U.S. gallon) waste containers with and without a transmission modality. A new model-based variant of differential attenuation has been developed that provides a high-quality self-absorption correction that does not require knowledge of the Uranium enrichment or isotopic ratios. For more challenging waste containers, a method using multi-view (non-rotating) 18.9 liter waste containers has been considered using a recently developed Advanced ISOCS{sup C} Uncertainty Estimator (AIUE) package. The new methods suffice to significantly improve accuracy and precision and to lower the Total Measurement Uncertainty (TMU) leading to satisfactory DQO's that were not previously achievable using the standard gamma attenuation correction methods. In this paper we present real 18.9 liter waste container and Working Reference Material (WRM) data subjected to the new methods and compared to standard methods depicting the significant improvement in the DQO that is realized. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2017

Rapid methods for radionuclide contaminant transport in nuclear fuel cycle simulation

Here, nuclear fuel cycle and nuclear waste disposal decisions are technologically coupled. However, current nuclear fuel cycle simulators lack dynamic repository performance analysis due to the computational burden of high-fidelity hydrolgic contaminant transport models. The Cyder disposal environment and repository module was developed to fill this gap. It implements medium-fidelity hydrologic radionuclide transport models to support assessment appropriate for fuel cycle simulation in the Cyclus fuel cycle simulator. Rapid modeling of hundreds of discrete waste packages in a geologic environment is enabled within this module by a suite of four closed form models for advective, dispersive, coupled, and idealized con- taminant transport: a Degradation Rate model, a Mixed Cell model, a Lumped Parameter model, and a 1-D Permeable Porous Medium model. A summary of the Cyder module, its timestepping algorithm, and the mathematical models implemented within it are presented. Additionally, parametric demonstrations simulations performed with Cyder are presented and shown to demonstrate functional agreement with parametric simulations conducted in a standalone hydrologic transport model, the Clay Generic Disposal System Model developed by the Used Fuel Disposition Campaign Department of Energy Office of Nuclear Energy.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2024

Chlorination of HALEU regulus casting dross

A scoping study was performed for chlorinating dross formed during uranium casting operations. Here, the purpose is to minimize the losses of uranium to dross wastes. The dross is primarily a mixture of uranium metal and uranium oxide with a minor fraction of crucible and crucible coating materials. The reaction chemistries were performed in a carrier salt of LiCl-KCl eutectic at 500 °C. The addition of FeCl 2 chlorinated the uranium metal to UCl 3 , by reducing the FeCl 2 to iron metal. After the uranium metal was chlorinated, zirconium metal was added to the salt. The residual FeCl 2 chlorinated the zirconium metal to ZrCl 4 , by reducing the FeCl 2 to iron metal. In turn, the ZrCl 4 chlorinated the uranium oxide to UCl 3 , by converting the ZrCl 4 to zirconium oxide. The effectiveness of the chlorination reactions was qualitatively verified by cyclic voltammograms that indicated the presence or absence of FeCl 2 and UCl 3 in the salt.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2016

NJOY2016

NJOY2016 is used to convert evaluations in the Evaluated Nuclear Data Files (ENDF) format into forms useful for practical applications such as fission and fusion reactor analysis, criticality safety, radiation shielding, nuclear waste management, nuclear medicine procedures, and more. It begins with the generation of pointwise libraries, including reaction and resonance reconstruction, Doppler broadening, radiation heating and damage, thermal scattering data, unresolved resonance data, and gas production. It reviews the production of libraries for the continuous-energy Monte Carlo code MCNP, multigroup neutron, photon, and particle cross sections and matrices, and photon interaction data. Uncertainty information for ENDF data is processed, including the capability for calculating covariances of resonance data, angular distributions, energy distributions, and radioactive nuclide production. NJOY can prepare and process thermal scattering data evaluations into application libraries. It can also plot cross sections, angular distributions and secondary emission spectra.

Kahler III, A. C. (Skip)↗

DOE OSTI2012

Compact Process Development at Babcock & Wilcox

Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of compaction trials have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel at packing fractions exceeding 46% by volume. Results from these trials are included. The scale-up effort is nearing completion with the process installed and operable using nuclear fuel materials. Final process testing is in progress to certify the process for manufacture of qualification test fuel compacts in 2012.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

NASA NTRS1991

Lunar hydrogen extraction

This paper examines the power and mass requirements of a lunar hydrogen extraction plant producing five metric tons of hydrogen per year. These power and mass requirements are based upon experimental work that determined gaseous hydrogen release rates from lunar samples at various heating rates and temperatures. An optimum heating temperature and rate can be selected to minimize the processing plant's power and mass requirements. The impact of thermal recovery on the power and mass requirements is studied, as is the use of nuclear waste heat for processing the regolith. In addition, the potential of using the extracted hydrogen in the form of methane as a propellant for a Lunar Excursion Vehicle is examined.

Snaufer, M. J.↗

NASA NTRS1999

Optical Analysis of Impact Features in Aerogel From the Orbital Debris Collection Experiment on the MIR Station

The Mir Environmental Effects Package (MEEP) was deployed on the Mir station and retrieved after 18 months in space. The payload included the orbital debris collector (ODC), designed and built at the Johnson Space Center to capture and return analyzable residues of the man-made and natural particulate environment in low-Earth orbit for a detailed assessment of its compositional makeup and potential origins. The ODC exposed 2 identical trays, with highly porous, low-density SiO2 aerogel as the basic collector medium, pointed in opposite directions. The aerogel was expected to gently decelerate and capture hypervelocity particles, as opposed to other media that resulted in melting or vaporization of many impactors. Even cursory examination of the returned ODC collectors revealed a surprising variety of impact features. The compositional analyses using scanning electron "miccroscope-energy-dispersive X-ray spectroscopy concentrated on a survey-type inventory of diverse particle types and associated impact features. Detections, in the form of carrot-shaped tracks and shallow pits, included metallic Al, stainless steel, soldering compounds, human waste, and paint flakes. Many pits contained no detectable impactor residue (it was assumed to have vaporized), but most of the tracks contained analyzable residue. The study showed that aerogel would be useful for future low-velocity impact analysis.

Hoerz, Friedrich↗

DOE OSTI2012

Compaction Scale Up and Optimization of Cylindrical Fuel Compacts for the Next Generation Nuclear Plant

Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of designed experiments have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel. Results from these experiments are included. The scale-up effort is nearing completion with the process installed and operational using nuclear fuel materials. The process is being certified for manufacture of qualification test fuel compacts for the AGR-5/6/7 experiment at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2016

NJOY2016

NJOY2016 is used to convert evaluations in the Evaluated Nuclear Data Files (ENDF) format into forms useful for practical applications such as fission and fusion reactor analysis, criticality safety, radiation shielding, nuclear waste management, nuclear medicine procedures, and more. It begins with the generation of pointwise libraries, including reaction and resonance reconstruction, Doppler broadening, radiation heating and damage, thermal scattering data, unresolved resonance data, and gas production. It reviews the production of libraries for the continuous-energy Monte Carlo code MCNP, multigroup neutron, photon, and particle cross sections and matrices, and photon interaction data. Uncertainty information for ENDF data is processed, including the capability for calculating covariances of resonance data, angular distributions, energy distributions, and radioactive nuclide production. NJOY can prepare and process thermal scattering data evaluations into application libraries. It can also plot cross sections, angular distributions and secondary emission spectra.

Kahler III, A. C. (Skip)↗

DOE OSTI2013

Memory Saves Lives: Inter-generational Warnings Effectiveness - 13556

The 2011 Tohoku earthquake and tsunami was a world-class natural disaster. It has been described as the most powerful earthquake ever in Japan, and as one of the most powerful earthquakes ever noted in the world. The toll in terms of human lives lost and property destruction was unimaginable. Even the word 'horrible' is inadequate to describe the suffering and misery that resulted. Nations with nuclear power programs are engaged in, or at least planning to become engaged in, arranging to eventually dispose of their higher-level radioactive waste materials in deep geologic repositories. Geologic repositories are passive safety systems, and if undisturbed isolate these dangerous materials form the biosphere for extremely long times. The key words, however, are 'if undisturbed'. To assure that future generations do not inadvertently drill into repositories, national programs, and the international community (the Records, Knowledge and Memory (RK and M) preservation project of the Nuclear Energy Agency, for example), are proposing to place markers and/or monuments on closed repository sites that say 'do not drill here, and this is why' in various sophisticated ways. Such markers or monuments are attempts at providing passive institutional controls. The effectiveness of messages from past generations to a present generation may give an indication of how effective such passive institutional controls may be. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗