Search NASA⌕ Search

SEARCH · Search NASA

Results for “waste utilization”

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 757 records · Page 42

AVANTech's Innovative LLW Concentrate Treatment System Reducing Environmental Releases - 16416

Russian Water-Water Energetic Reactors (VVER) and some Pressurized Water Reactors (PWR) utilize evaporator or reverse osmosis units to generate concentrate that must be disposed as LLRW. The new AVANTech Concentrate Treatment System (CTS{sup TM}) was developed to decontaminate the concentrate to the point where the dry solids after evaporation are free releasable to the environment and the radioactive waste generated represents less than 3% of the original concentrate volume, thus decreasing disposal costs substantially. These concentrate solids can be recycled to non-nuclear applications or disposed as industrial waste. Bench-scale testing has been completed with actual concentrate waste from two VVER plants with final results less than the IAEA General Safety Requirements (GSR) Part 3 discharge requirements. The VVER plants utilize chelants to conduct periodic decontamination of the piping systems that must be destroyed before utilizing precipitants and ion exchange to remove most of the isotopes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Natural variability and antioxidant properties of commercially cultivated switchgrass extractives

Optimum utilization of lignocellulosic bioenergy feedstock, such as switchgrass, via recovery of value-added phytochemicals and reduction of waste streams will increase the economic feasibility as well as the sustainability of integrated biorefineries. Switchgrass contains significant amount of overlooked non-structural components, i.e. extractives, which encompasses phenolic derivatives with potential antimicrobial and antioxidant properties. As a perennial crop, it is essential to assess the natural variability of switchgrass extractives content and composition in order to determine the feasibility of its extraction and utilization. In this study, three switchgrass cultivars were harvested from four commercial farms in their second and third growing seasons. Their respective extractive fractions were characterized for the presence of free sugars, total phenolics (TPC), hydroxycinnamic acid (HCAs) derivatives, total flavonols, and other important phytochemicals. Biomass harvested in the third growing season displayed greater amounts of TPC, HCAs, and total flavonols. Environmental conditions such as total precipitation, and cultural practices including harvest time, played important roles in the accumulation of TPC. As a result, the switchgrass extractives also exhibited DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity with a positive correlation between inhibiting concentration (IC 50 ) value and total flavonols content.

59 BASIC BIOLOGICAL SCIENCES↗

Collaborative Management for Complex Closure Teams - 19246

The closure documentation for government waste management sites requires a multidisciplinary approach to achieve success. This approach is necessary and similar to approaches utilized across remediation projects in the private and public sectors [1]. Closure documentation for government projects can range from tens of pages to upwards of thousands of pages. They normally take more than six months to put together - although, in many cases, it takes years - with multiple revisions. These documents, while all unique, share common themes with regards to communication and conflict with the other waste management projects. This paper explores the challenges in management and leadership approaches for generating technical documents, such as those found in the closure missions at government hazardous waste management sites. These matrixed teams are composed of many different members with varying expertise and experience, each with different stakeholder backgrounds. These teams experience challenges not only from using a matrixed approach - where the majority of the members are only partially engaged in the project - but also from integrating each of their respective stakeholder group's cultural individualities [2]. The Project Leads, who head up these highly matrixed projects, operate in environments comprised of virtual project teams- or more specifically in this context, intensive virtual project teams. Most of the participants are within the same city, but all of the document project teams operate with some level of organizational dispersion. Moreover, the larger a project becomes the more dispersed the team becomes. The frequent addition of sub-contracting resources by Project Leads further disperses the group and dilutes communication. The difficulties in communication derive from complications in the goal setting stages of a project and can manifest across the project team in the form of motivational issues, disengagement, quality expectations, and a loss of understanding. This puts a considerable amount of importance on a Project Lead to establish goals through the appropriate tools and methodology. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Electric load shape benchmarking for small- and medium-sized commercial buildings

Small- and medium-sized commercial buildings owners and utility managers often look for opportunities for energy cost savings through energy efficiency and energy waste minimization. However, they currently lack easy access to low-cost tools that help interpret the massive amount of data needed to improve understanding of their energy use behaviors. Benchmarking is one of the techniques used in energy audits to identify which buildings are priorities for an energy analysis. Traditional energy performance indicators, such as the energy use intensity (annual energy per unit of floor area), consider only the total annual energy consumption, lacking consideration of the fluctuation of energy use behavior over time, which reveals the time of use information and represents distinct energy use behaviors during different time spans. To fill the gap, this study developed a general statistical method using 24-hour electric load shape benchmarking to compare a building or business/tenant space against peers. Specifically, the study developed new forms of benchmarking metrics and data analysis methods to infer the energy performance of a building based on its load shape. We first performed a data experiment with collected smart meter data using over 2,000 small- and medium-sized businesses in California. We then conducted a cluster analysis of the source data, and determined and interpreted the load shape features and parameters with peer group analysis. Finally, we implemented the load shape benchmarking feature in an open-access web-based toolkit (the Commercial Building Energy Saver) to provide straightforward and practical recommendations to users. The analysis techniques were generic and flexible for future datasets of other building types and in other utility territories.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Dehalogenation reactions between halide salts and phosphate compounds

Reactions between phosphoric acid [H 3 PO 4 ] or ammonium hydrogen phosphates [i.e., NH 4 H 2 PO 4 , (NH 4 ) 2 HPO 4 ] and halide salts can be used to dehalogenate (remove halides from) salt-based waste streams, where the process of removing halides yields products that have more efficient disposal pathways for repository storage. In this context, the term efficiency is defined as higher waste loadings and simplified immobilization processes with potential for recycle of certain salt components (e.g., 37 Cl as H 37 Cl or NH 4 37 Cl). The main streams identified for these processes are nuclear wastes generated during electrochemical reprocessing of used nuclear fuel as well as used halide salts from molten salt reactor operation. The potential byproducts of these reactions are fairly consistent across the range of halide species (i.e., F, Cl, Br, I) where the most common are hydrogen halides [e.g., HCl (g) ] or ammonium halides (e.g., NH 4 Cl). However, trihalide compounds (e.g., NCl 3 ), nitrogen triiodide ammine adducts [NI 3 ·(NH 3 ) x ], and ammonium triiodide (NH 4 I 3 ) are also possible. Several of these byproducts (i.e., NCl 3 , NBr 3 , NI 3 , and NH 4 I 3 ) are shock-sensitive contact explosives so their production in these processes must be tracked and carefully controlled, which includes methods of immediate neutralization upon production such as direct transport to a caustic scrubber for dissolution. Several benefits arise from utilizing H 3 PO 4 as the phosphate additive during dehalogenation reactions for making iron phosphate waste forms including more oxidized iron (higher Fe 3+ :Fe 2+ ratios), higher chemical durabilities, and the avoidance of trihalides, but the byproducts are hydrogen halides, which are corrosive and require special handling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

SISTec: Mathematical Calibration of Large Clearance Monitors - 18265

One major path for clearance of large amount of waste arising from the decommission of nuclear power plants is based on measurement with large clearance monitors (also known as free release measurement facilities). These devices utilize multi-detector plastic scintillator arrays (large clearance monitors can consist of up to 24 plastic scintillators) to offer both, extremely low minimum detectable activities (MDA) and short measurement times for waste packages weighing up to one metric ton. However, a major problem with these devices is to obtain nuclide specific efficiencies, especially for geometrically complex large waste packages. Normal procedure for estimating the efficiency is to device dummy waste packages and attach point sources with well-known activities to unfavourable positions in these packages. In accordance with this procedure, calibration factors can be derived in a radiological conservative way. Devising such test dummies is not always possible and the procedure is prone to generating large measurement uncertainties. In this publication, we propose a new method to derive calibration factors by means of the Los Alamos National Laboratory (LANL) simulation tool Monte Carlo N-Particle (MCNP) and a statistical-phenomenological model for the detector characterization. In a multi-step approach, first the detector response for a distribution of activity in a waste package is calculated and subsequently the detectors are mathematically characterized. Applying state of the art statistical and optimizing procedures, parameters for the detector response are derived in a self-consistent way. This also allows to rigorously propagate the uncertainties to the final calculated calibration factors according to the Guide to the Expression of Uncertainty in Measurement (GUM supplement 1). To validate the derived parameters for the detector characterization a minimally invasive experimental setup was devised and installed into the large clearance monitor. It consisted of an aluminum swivel arm which could position point sources to the relevant coordinates. The so collected measurement data not only allowed to investigate the precision of the calculated calibration factors, but also to probe the location of concentrated activity sources in the waste package. Furthermore, data on measurements with dummy waste packages were collected to test the reproducibility of well-known calibration factors. We present the software tool SIStec, which will provide an intuitive user-interface to generate and simulate waste package models and execute the above-mentioned method. Using SIStec, different scenarios for the distribution of activity in the waste package can be probed. This will also allow to optimize the clearance process on various levels. For example, measurement time for pre-measurements can be reduced in exchange for unfavourable calibration factors, which would still allow to meet the regulator limits for clearance. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Tank Closure Cesium Removal at Savannah River Site - 19604

Savannah River Remediation (SRR) has developed a supplemental at-tank ion exchange capability for the removal of cesium from liquid salt waste. Building on the development of previous ion exchange initiatives and the experience of commercial nuclear plant decontamination services, and following the disaster response associated with Fukushima, the technology has matured to deploy a modular at-tank treatment system for the selective removal of cesium from bulk salt waste. If feasible, this Tank Closure Cesium Removal (TCCR) initiative would provide a supplemental treatment capability to existing and future salt processing and improve confidence in supporting the desired acceleration of waste retrieval and tank closure efforts. In addition to accelerating waste retrieval and tank closure activities, demonstration of this capability has several other benefits. Deployment of commercially available technologies with minor modification can expand Department of Energy (DOE) utilization of commercially supplied treatment processes. This 'at-tank' treatment system could be modified to evaluate and demonstrate removal of other radioactive constituents (strontium, technetium, iodine, etc.) of bulk waste. The modular aspect of this capability can allow for additional units to be delivered and deployed at SRS, as well as, provide supplemental treatment capabilities for waste treatment at other DOE sites. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Utilizing Temperature and Brine Inflow Measurements to Constrain Reservoir Parameters During a Salt Heater Test

Brine availability in salt has multiple implications for the safety and design of a nuclear waste storage facility. Brine availability includes both the distribution and transport of brine through a damaged zone around boreholes or drifts excavated into the salt. Coupled thermal, hydrological, mechanical, and chemical processes taking place within heated bedded salt are complex; as part of DECOVALEX 2023 Task E this study takes a parsimonious modeling approach utilizing analytical and numerical one-dimensional simulations to match field measurements of temperature and brine inflow around a heater. The one-dimensional modeling results presented arrive at best-fit thermal conductivity of intact salt, and the permeability and porosity of damaged salt of 5.74 W/m∙K, 10 –17 m 2 , and ≈ 0.02, respectively.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Large Cask, Small Building, AREVA's Safe MLLW Disposal Solution Despite Facility Limitations - 16295

In order to begin decommissioning of a 1950's research reactor, Class C Mixed Low Level Waste (MLLW) had to be removed from the facility and disposed of. The AREVA TN RAM cask, designed and licensed for shipping Type B waste packages, was chosen as the most appropriate shipping solution. Due to the building layout, crane capacity and pool size, the standard TN RAM cask loading process could not be utilized. Unique solutions and approaches had to be developed to complete the project. AREVA designed a smaller liner insert that would house the four MLLW components in a single waste package to solve the problems related to crane capacity and physical pool dimensions. AREVA also designed and fabricated a shield bell to provide radiation shielding while moving the liner insert from the reactor pool to the cask that was staged adjacent to the reactor pool. The AREVA team worked with the disposal facility to cover requirements for disposal of Class B MLLW. This included designing spacers filled with inert material to fulfill the requirement for maximum 10% void space in the waste package. This disposal method for Class C waste met the requirements of macro-encapsulation. Therefore, no additional treatment action was required when disposing of Class C MLLW. AREVA's solution provides a model for disposing MLLW requiring macro-encapsulation in a single waste package. This solution also provides a model for how to adapt large shipping casks and liners to smaller aging commercial, DOE or research facilities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

A newly proposed isotherm model to predict Cs exchange with crystalline silicotitanate in tank waste simulants

The Zheng Anthony Miller (ZAM) computer model, a multicomponent ion exchange model used to predict the exchange of Group I metals onto crystalline silicotitanate (CST), has historically been used to predict Cs distribution coefficients from Hanford and Savannah River Site (SRS) tank waste simulants. Comparison of experimentally determined Cs distribution coefficients from tank waste simulants with ZAM isotherm model predictions indicate overprediction of Cs and K distribution coefficients for simple and complex simulants with the engineered form of CST. Additionally, recent changes in chemical composition/manufacturing of IONSIV TM R9140-B have resulted in increased Cs capacity from high-salt, highly alkaline solutions. Here, this work served to assess different isotherm models and refine equilibrium parameters to develop a model that can be applied to Hanford and SRS tank waste Cs removal efforts. Toward this goal, the Campbell Westesen Peterson (CWP) model was developed. This model utilized the experimentally determined Cs capacity, and simplified ZAM equilibria expressions to include only the binary substitution of Cs + or K + on the Na + sites. Equilibrium constants for these equations were refined using experimentally determined distribution coefficients. Overall, the CWP model significantly improved our ability to predict both Cs and K loading capacity from complex matrices.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

A Monte Carlo Rectangle Packing Algorithm for Identifying Likely Spatial Distributions of Final Closure Cap Subsidence in the E-Area Low-Level Waste Facility

A Monte Carlo rectangle packing algorithm, summarized in Figure ES-1, has been developed to provide insights into the likely spatial distribution of subsided areas or holes in the final closure cap for the E-Area Low-Level Waste Facility (ELLWF) resulting from the placement of non-crushable waste containers within slit and engineered trench disposal units. Using historical records provided by Solid Waste Management as an indicator of future waste streams, a probability distribution of unique waste containers was constructed, and Monte Carlo sampling was used to sequentially select waste containers for placement in a rectangular region bounded by the disposal unit footprint. Within this Monte Carlo approach, the probability of any container type being selected is weighted by the fractional abundance relative to all other container types. For each Monte Carlo realization, the frequency of non-crushable waste containers appearing at each location on a spatially discretized mesh is updated. After many realizations, the location(s) with the highest frequencies of non-crushable waste containers are regarded as the most likely locations to experience subsidence (i.e., for a hole to form). Utilizing this approach has enabled the down-selection of a computationally intractable set of subsidence hole combinations to be explored in three-dimensional finite element groundwater flow and contaminant transport models. Such an approach can be applied to a number of different packaging problems.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

How To Throw A Zero Waste Event

This is a presentation outlining how one might promote a zero waste event.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Recovery and Enhanced Upgrading of Rare Earth Elements from Coal-Based Resources: Bioleaching and Precipitation

Rare earth elements (REEs) are of great importance to modern society and their reliable supply is a major concern of many industries that utilize them in metal alloys, semiconductors, electrical equipment, and defense equipment. REEs in the coal waste have been revealed to be an alternative resource for REEs production. In this study, the extraction, recovery, and upgrading of the REEs from coal waste has been realized with the bioleaching and precipitation processes. Reliable and sustainable acid and oxidant production from the oxidation of the pyrite with Acidithiobacillus ferrooxidans to generate acid for leaching were realized in this research. The acidified bioleaching solution was used to extract REEs from coal waste, with 13–14% yields for most REE elements (~72 h of leaching). However, recovery for longer duration tests was significant higher (varies from 40–60% for individual REEs). After extraction, precipitation and separation processes were designed with the aid of Visual Minteq calculations and modeling to concentrate the REEs. With the procedures designed in this research, a final REEs precipitate product containing 36.7% REEs was produced.

01 COAL, LIGNITE, AND PEAT↗

The MIST /MIUS Integration and Subsystems Test/ laboratory - A testbed for the MIUS /Modular Integrated Utility System/ program

The MIUS (Modular Integrated Utility System) concept is to be an energy-conserving, economically feasible, integrated community utility system to provide five necessary services: electricity generation, space heating and air conditioning, solid waste processing, liquid waste processing, and residential water purification. The MIST (MIUS Integration and Subsystem Test) integrated system testbed constructed at the Johnson Space Center in Houston includes subsystems for power generation, heating, ventilation, and air conditioning (HVAC), wastewater management, solid waste management, and control and monitoring. The key design issues under study include thermal integration and distribution techniques, thermal storage, integration of subsystems controls and displays, incinerator performance, effluent characteristics, and odor control.

Beckham, W. S., Jr.↗

Deployable radiators for waste heat dissipation from Shuttle payloads

Thermal control of Shuttle instruments will require the use of a pumped fluid space radiator system to reject large quantities of waste heat. Many payloads, however, will have insufficient vehicle surface area available for radiators to reject this waste heat and will, therefore, require the use of deployed panels. It is desirable to utilize modularized, deployable radiator systems which have a high degree of configuration and component commonality to minimize the design, development, and fabrication costs. Prototypes of two radiator systems which meet these criteria are currently under development for Shuttle payload utilization: a 'rigid' radiator system which utilizes aluminum honeycomb panels of the Shuttle Orbiter configuration that are deployed by an Apollo Telescope Mount type scissors mechanism; and two 'flexible' radiator systems which use panels constructed from flexible metal/dielectric composite materials that are deployed by 'unrolling' or 'extending' in orbit. Detailed descriptions of these deployable radiator systems, along with design and performance features, are presented.

Cox, R. L.↗

Production of oxygen from lunar ilmenite

The following subjects are addressed: (1) the mechanism and kinetics of carbothermal reduction of simulated lunar ilmenite using carbon and, particularly, CO as reducing agents; (2) the determination of the rate-limiting steps; (3) the investigation of the effect of impurities, particularly magnesium; (4) the search for catalysts suitable for enhancement of the rate-limiting step; (5) the comparison of the kinetics of carbothermal reduction with those of hydrogen reduction; (6) the study of the combined use of CO and hydrogen as products of gasification of carbonaceous solids; (7) the development of reduction methods based on the use of waste carbonaceous compounds for the process; (8) the development of a carbothermal reaction path that utilizes gasification of carbonaceous solids to reducing gaseous species (hydrocarbons and carbon monoxide) to facilitate the reduction reaction kinetics and make the process more flexible in using various forms of carbonaceous feeds; (9) the development of advanced gas separation techniques, including the use of high-temperature ceramic membranes; (10) the development of an optimum process flow sheet for carbothermal reduction, and comparison of this process with the hydrogen reduction scheme, as well as a general comparison with other leading oxygen production schemes; and (11) the use of new and advanced material processing and separation techniques.

Zhao, Y.↗

From Regolith to Living Off the Land: Formulating a Data Model to Catalog Lunar Construction Materials

Artemis Program objectives for sustainable, long-term presence on the Moon and more distant planetary surfaces will require learning to “Live off the Land”, relying on in-situ resource utilization to produce infrastructure and building materials from lunar regolith, icy subsurface deposits, and residual waste materials. Meeting demand for consumables while scaling development with resources found within the landing zone will require detailed data on the geology and environment of the lunar surface. Lunar infrastructure development will generate vast amounts of new engineering data regarding availability of processed feedstocks and their performance in building materials. Lunar engineering data accessible to program partners, research institutions and industry may help situate processes and specifications within the in-situ GIS context. Lunar missions to date have generated geological and ice favorability maps of the lunar surface, and recent technology studies have tested automated construction systems and novel material formulations using regolith simulants and binders. Current discussions focus on identifying key feedstocks, quantities required for nominal mission scenarios and infrastructure plans, and mapping the value chain from regolith to feedstock to consumables and construction materials.

lunar construction↗