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NASA NTRS2021

Feasibility of Earthbound Motion in Lunar Gravity

BACKGROUND: Marginal stability of astronaut movement while performing lunar surface tasks has been well documented, and is clearly demonstrated in videos of falls, and near falls, during Apollo Lunar Extravehicular Activities. Referencing mission reports from Apollo 15 and 16 [1, 2], suspected causes for falls include: surface conditions, visibility, and gravitational effects (hypogravity). In this preliminary test, we employ the open-source biomechanical tool OpenSim [3, 4] to analyze the impact of lunar gravity (Lg) on two object-pickup motions performed by a single shirt-sleeved subject. Specifically, we attempt to answer the following questions based on an estimation of the Center of Mass Projection (CoMP) and ground reaction force Center of Pressure (COP) as it relates to the astronaut Base of Support (BOS) for 1g and Lg conditions: 1. Is the task motion, as performed in 1g, dynamically feasible in 1g and Lg? 2. Can we make the motion dynamically feasible in Lg by slowing it down? 3. Is the Lg COP equal to the 1g COP at a theoretically predicted reduction in motion speed? METHODS AND RESULTS: To answer the first question, the gravitational acceleration in the OpenSim model is modified from a nominal 9.81 m/s2 to 1.64 m/s2, and the 1g joint trajectory is input to an OpenSim based method [5] for estimating ground reaction forces and moments. From this method, the position of the CoMP and COP can be estimated and checked to see if they remain within a simulated BOS formed from the footprint of the OpenSim model to determine whether the motion is dynamically feasible. As expected, both of the motions were estimated to be feasible in a 1g environment, however, both motions had periods of infeasibility in Lg. It is well known that crew members make adjustments to motion trajectories in altered gravity fields to maintain balance. As a first step, we considered the simple adjustment of slowing the motion in Lg by a constant factor. This was accomplished by scaling the time stamps in the motion trajectory file by that factor. For the two motions considered, it was found that scale factors of 1.3 and 1.4 kept the COP just within the subject BOS. The CoMP is unchanged by the gravity field. Simple analysis of an inverted pendulum in the Lg environment, which generalizes to a general multibody system, leads to a theoretical prediction that a reduction in speed factor of √1g/Lg, or 2.445, will make the COP trajectory in Lg equivalent to that in 1g. When the above procedure was performed with a factor of 2.445, the estimated COP in Lg, was observed to be very close to that in 1g. In summary, we have developed a method for estimating the CoMP and COP in Lg, for subject motion collected in 1g. We believe this method can prove to be a valuable check and balance for simulated Lg training and testing by exposing potential simulator-induced artifacts that make the simulated task motion seem possible, when in fact, it would violate the above criteria. We also note that a reduction in task speed should tend the task motion towards stability, with a theoretical slowdown factor of √1g/Lg making the motion stability equal to that in 1g according to the CoMP and COP criteria.

R K Huffman↗

DOE OSTI2017

Estimation and Fusion for Tracking Over Long-Haul Links Using Artificial Neural Networks

In a long-haul sensor network, sensors are remotely deployed over a large geographical area to perform certain tasks, such as tracking and/or monitoring of one or more dynamic targets. A remote fusion center fuses the information provided by these sensors so that a final estimate of certain target characteristics – such as the position – is expected to possess much improved quality. In this paper, we pursue learning-based approaches for estimation and fusion of target states in longhaul sensor networks. In particular, we consider learning based on various implementations of artificial neural networks (ANNs). Finally, the joint effect of (i) imperfect communication condition, namely, link-level loss and delay, and (ii) computation constraints, in the form of low-quality sensor estimates, on ANN-based estimation and fusion, is investigated by means of analytical and simulation studies.

97 MATHEMATICS AND COMPUTING↗

NASA NTRS1972

Refurbishment cost study of the thermal protection system of a space shuttle vehicle, phase 2

Labor costs and techniques associated with the refurbishment of representative TPS and their attach concepts suitable for space shuttle application have been identified on the basis of experimental tests. Ablative and reusable surface insulation TPS configurations were designed, fabricated, and tested on a full-scale mockup. The TPS attachment methods investigated included pi-strap, multiple mechanical fasteners, key/keyway, and direct bond concepts. Techniques for performing installation, inspection, repair and replacement of TPS components were studied by examining a variety of shop procedures. Major problem areas associated with these procedures and the designs to which they were applied were analyzed for several significant parameters such as handling, gaskets between joints, repair techniques, ablator plugs, etc. Results of time and motion studies of specific maintenance tasks, simulating operational procedures, were obtained. Using these data, refurbishment labor cost projections were generated for a representative Space Shuttle orbiter.

Haas, D. W.↗

NASA NTRS1982

Helicopter simulation validation using flight data

A joint NASA/Army effort to perform a systematic ground-based piloted simulation validation assessment is described. The best available mathematical model for the subject helicopter (UH-60A Black Hawk) was programmed for real-time operation. Flight data were obtained to validate the math model, and to develop models for the pilot control strategy while performing mission-type tasks. The validated math model is to be combined with motion and visual systems to perform ground based simulation. Comparisons of the control strategy obtained in flight with that obtained on the simulator are to be used as the basis for assessing the fidelity of the results obtained in the simulator.

Key, D. L.↗

DOE OSTI2017

High Dexterity Robotics for Safety and Emergency Response - 17104

Recently, significant advances in robotics have led to increased use in industrial and military applications. For example, the military has used explosive ordnance disposal (EOD) robots to enable responders to remotely investigate hazardous environments. While EOD robots have saved many lives, their utility is hampered by: 1) limited ability to manipulate complex objects and mechanisms (e.g. open a car door, operate power tools or turn valves), and 2) the requirement for significant operator training using joystick-type interfaces. Most robots today have simplistic manipulators and cannot easily operate in environments designed for humans as evidenced by the recent Amazon Picking Challenge and the DARPA Robotics Challenge. Simple tasks that humans perform easily, such as picking up objects or operating a cutting tool, require customized rigs that are expensive and time-consuming to use. The specialized nature of these robots limits their utility in highly unstructured environments, for example during emergency situations where a robot may need to be rapidly re-purposed for an unanticipated situation (i.e. the Fukushima nuclear disaster). Robots are needed that can perform complex human-like tasks and are easy to use for everyday and emergency tasks. In 2005 the Defense Advanced Research Projects Agency (DARPA) initiated the Revolutionizing Prosthetics (RP) Program with the goal of creating prosthetics as capable as the human arm and a human-machine interface enabling highly intuitive operation. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) created the Modular Prosthetic Limb (MPL), originally developed for amputees and paralyzed individuals as part of the RP Program, to replicate the capability of the human hand and arm to the extent technologically possible. With 26 joints and over 180 sensors, it is one of the most sophisticated and fully integrated robotic arms in the world. We have also demonstrated human-machine interface techniques that are highly intuitive requiring minimal training. While the MPL was originally designed as a prosthetic, it has also been incorporated into mobile robotic systems to project human capability. Using tele-operation, we have demonstrated the ability to perform dual-arm remote operations in complex environments. For nuclear facilities, high dexterity robots combined with tele-operation offer the potential to enhance worker safety, productivity and quality. Safety enhancements include enabling remote operation in hazardous environments, remote handling of heavy or dangerous materials, and elimination of injury due to repetitive motions. Because the MPL is designed to function like a human limb, the robot can work in environments designed for humans with limited need for specialized tools. When used for routine operations, it can also maintain a level of familiarity and confidence that effectively accomplishes reinforcement training for use in emergency situations, unlike a specialized robot that might sit unused for months or years at a time. In August 2016 we demonstrated the use of the MPL at the Portsmouth Gaseous Diffusion Plant in Piketon, Ohio. Two robotic platform technologies were demonstrated to familiarize the DOE Emergency Management's (EM) workforce on the potential benefits of this technology. Here we present the results of those efforts, highlight the lessons learned during 'EM Week,' and outline potential future developments that could further advance application of these technologies to enhance worker safety. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

NASA NTRS2020

History and Logic Model NASA Goddard Space Flight Center Instrument and Payload Systems Engineering Technical Performance Study

Historically, some NASA missions have exceeded schedule and cost commitments. Studies suggest technical performance is a contributor. The 1980 NASA Project Management Study concluded, "one of the most significant contributors to cost and schedule growth is inadequate definition of technical and management aspects of a program..." (as cited in GAO/NSIAD-93-97, p. 11). The 1991 NASA Roles and Missions Report identified a "need for increased emphasis on technological readiness and requirements on the front end of a program" (as cited in GAO/NSIAD-93-97, p. 11). The 1992 NASA Program Costs Report stated that NASA officials identified, among other things, "insufficient definition studies... [and] program redesigns and technical complexities" as reasons for cost and schedule overruns (GAO/NSAID-93-97, p. 11). The 2002 Task Force on Acquisition of National Security Space Programs found "requirements definition and control issues, unhealthy cost bias in proposal evaluation, widespread lack of budget reserves required to implement high risk programs on schedule, and an overall underappreciation of the importance of appropriately staffed and trained system engineering staff to manage the technologically demanding and unique aspects of space programs" (DoD, 2003, p.i.) In 2007, The NASA Office of the Chief Engineer chartered the NASA Instrument Capability Study (NICS) “to determine whether NASA instrument developers are facing challenges that impact the capability to design and build quality instruments or whether there are flaws in the acquisition strategy evidenced by schedule delays, cost overruns, and increased technical risk via design deficiencies. The... team was also chartered to determine if occurrences [are]... isolated cases or if there are generic issues... If the issues [are] found to be generic, the team [is] to offer solutions to recover such capability" (NICS Report, 2008, p. vi). The 2008 NICS Report, led by Goddard Space Flight Center (GSFC), identified challenges to instrument technical performance consistent with findings from previous reports. In 2017, the Instrument Project Division (IPD) Implementation Study was initiated to determine if there was a change in meeting schedule and cost commitments after implementing certain NICS recommendations. In 2018, the Instrument Technical Performance Study was initiated to determine the current state of Instrument Technical Performance in the GSFC Payload & Instrument Systems Engineering Branch. The purpose of the combined studies is to answer the question, "Is there a relationship between meeting NASA scientific instrument technical success and meeting schedule and cost commitments? If yes, what is the relationship?" References Department of Defense Office of the Under Secretary of Defense for Acquisition, Technology, and Logistics. (2003). The report of the defense science board/ air force scientific advisory board joint task force on acquisition of national security space programs. Washington DC. Government Accounting Office. (1992). NASA program costs: Space missions require substantially more funding than initially estimated. GAO/NSIAD-93-97. Washington DC. National Aeronautics and Space Administration, National Oceanic and Atmospheric Agency, Department of Defense. (2008). The NASA instrument capability study final report. NP-2008-11-058-GSFC. Washington DC.

Robbins, Geraldine↗

NASA NTRSDate not supplied

Shoulder Postures in EVA Training in Reduced Gravity Analogues

Shoulder Postures in EVA Training in Reduced Gravity Analogues K. Guhl1, L. Vu2, H. Kim3, S. Rajulu4 1KBR Inc., Houston, TX, 2Aegis Aerospace Inc., Houston, TX, 3Leidos Innovations, Houston, TX, 4NASA Johnson Space Center, Houston, TX. During extravehicular activities (EVAs) and EVA training in both the Neutral Buoyancy Laboratory (NBL) and at the Active Response Gravity Offload System (ARGOS), crewmembers perform a variety of hand-intensive tasks with frequent arm/shoulder repositioning while wearing a pressurized spacesuit. As a result, crewmembers may experience ergonomic stressors such as awkward shoulder postures. The ergonomic shoulder risk is also compounded by limited or restricted shoulder mobility of the spacesuit, extreme work positions such as overhead tasks, and tasks with heavy tools and repetitive motions. Prolonged or frequent shoulder elevation and overhead work, in particular, can lead to excessive stresses and musculoskeletal injuries of the shoulder joints. Future EVA missions, specifically lunar surface EVAs, will also be longer in duration and thus increase the exposure to awkward shoulder postures. In this study, we aimed to assess the ergonomic risk of awkward shoulder postures in simulated lunar surface EVAs by quantifying when and how long the arms are raised above the chest level. We assessed video recordings of pilot lunar EVA simulations (3 lunar trials each in the NBL and at ARGOS and 2 microgravity EVA trials in the NBL). These runs consisted of both training and engineering test objectives. Actual demands for shoulder use varied for different EVA types and analogues, but many EVA runs have common tasks and require similar motion components. A video observation and event logging software was used to document the duration and occurrence of the subject’s arms being raised throughout the video recordings of each EVA run. An arm raised instance was classified as the arm being at 90 degrees or above with relation to gravity for lunar EVA training events and with relation to the body for microgravity EVA training events. Such events included EVA hardware maintenance or heavy geology sampling tool operations. Events where the arm load was partially supported by external objects, like climbing a ladder or leaning against a surface were separately identified and excluded. Statistical analysis was performed to summarize the timing, frequency, and durations of the arm raise events and compared across the different EVA tasks and analogue types. Preliminary observations indicated that the total duration and number of arm raised instances were surprisingly smaller for lunar surface EVA training as compared to microgravity EVA training. The observed difference may be attributed to differing task demands and unique environmental characteristics found in lunar EVAs in comparison to microgravity EVAs. A detailed statistical analysis will be performed between lunar surface EVA training events and microgravity EVA training events in the final submission. Overall, this analysis is expected to provide insight into how ergonomic recommendations can be refined for lunar EVA training with pressurized suits. It may also inform task design and influence suit padding design to better protect crewmembers during future lunar training.

Kaitlyn Lea Guhl↗

NASA NTRS1999

Operational Processing of Ground Validation Data for the Tropical Rainfall Measuring Mission

The Tropical Rainfall Measuring Mission (TRMM) satellite was successfully launched in November 1997. A primary goal of TRMM is to sample tropical rainfall using the first active spaceborne precipitation radar. To validate TRMM satellite observations, a comprehensive Ground Validation (GV) Program has been implemented for this mission. A key component of GV is the analysis and quality control of meteorological ground-based radar data from four primary sites: Melbourne, FL; Houston, TX; Darwin, Australia; and Kwajalein Atoll, RMI. As part of the TRMM GV effort, the Joint Center for Earth Systems Technology (JCET) at the University of Maryland, Baltimore County, has been tasked with developing and implementing an operational system to quality control (QC), archive, and provide data for subsequent rainfall product generation from the four primary GV sites. This paper provides an overview of the JCET operational environment. A description of the QC algorithm and performance, in addition to the data flow procedure between JCET and the TRNM science and Data Information System (TSDIS), are presented. The impact of quality-controlled data on higher level rainfall and reflectivity products will also be addressed, Finally, a brief description of JCET's expanded role into producing reference rainfall products will be discussed.

Kulie, Mark S.↗

NASA NTRSDate not supplied

Exploration Extravehicular Mobility Unit (xEMU) Pressure Garment System (PGS) Cycle Testing Overview and Results

With the development of NASA’s next generation spacesuit, the hardware life expectations for the new spacesuit required evaluation. The xPGS team designed and performed a test series to assess the new hardware against the life requirements. The EMU on the International Space Station (ISS) today tests the life of the suit and new components by performing isometric individual joint cycle motions with the requirements based on previously performed Extra-Vehicular Activities (EVAs). The xPGS includes new designs for suit components to provide increased mobility for performance of lunar operations, thus the requirements for the life cycle of the suit had to be developed and tested with these new operations in mind. Cycle requirements shifted to cycles of functional tasks in lieu of isometric cycles to better understand the life of the suit. Manned cycle testing of the xPGS was conducted by performing repetitions of a series of tasks that reflect predicted Lunar EVA operations. The test series utilized a gravity offload system to simulate Lunar gravity environment. Cycle testing concluded after 30 test days in October of 2022 with lessons learned that will be critical for future spacesuit design. Specific lessons learned with regards to suit performance and test methodology will be provided.

spacesuit↗

DOE OSTI2024

Exploring the role of judgement and shared situation awareness when working with AI recommender systems

Abstract AI-advised Decision Making is a form of human-autonomy teaming in which an AI recommender system suggests a solution to a human operator, who is responsible for the final decision. This work seeks to examine the importance of judgement and shared situation awareness between humans and automated agents when interacting together in the form of a recommender systems. We propose manipulating both human judgement and shared situation awareness by providing the human decision maker with relevant information that the automated agent (AI), in the form of a recommender system, uses to generate possible courses of action. This paper presents the results of a two-phase between-subjects study in which participants and a recommender system jointly make a high-stakes decision. We varied the amount of relevant information the participant had, the assessment technique of the proposed solution, and the reliability of the recommender system. Findings indicate that this technique of supporting the human’s judgement and establishing a shared situation awareness is effective in (1) boosting the human decision maker’s situation awareness and task performance, (2) calibrating their trust in AI teammates, and (3) reducing overreliance on an AI partner. Additionally, participants were able to pinpoint the limitations and boundaries of the AI partner’s capabilities. They were able to discern situations where the AI’s recommendations could be trusted versus instances when they should not rely on the AI’s advice. This work proposes and validates a way to provide model-agnostic transparency into recommender systems that can support the human decision maker and lead to improved team performance.

Srivastava, Divya↗

DOE OSTI2018

Welding Defect Classification from Simulated Ultrasonic Signals

Nondestructive testing is widely used to detect and to size up discontinuities embedded in a material. Among the several ultrasonic techniques, time of flight diffraction (TOFD) combines high speed inspection, high sizing reliability and low rate of incorrect results. However, the classification of defects through ultrasound signals acquired by the TOFD technique depends heavily on the knowledge and experience of the operator and thus, this classification is still frequently questioned. Besides, this task requires long processing time due to the large amount of data to be analyzed. Nevertheless, computational tools for pattern recognition can be employed to analyze a high amount of data with large efficiency. In the present work, simulation of ultrasound propagation in two-dimensional media containing, each one, different kinds of modeled discontinuities which mimic defects in welded joints were performed. Clustering (k-means) and classification (principal component analysis and k-nearest neighbors) algorithms were employed to associate each simulated ultrasound signal with its corresponding modeled defects. The results for each method were analyzed, discussed and compared. The results are very promising.

42 ENGINEERING↗

NASA NTRS1989

A global approach for using kinematic redundancy to minimize base reactions of manipulators

An important consideration in the use of manipulators in microgravity environments is the minimization of the base reactions, i.e. the magnitude of the force and the moment exerted by the manipulator on its base as it performs its tasks. One approach which was proposed and implemented is to use the redundant degree of freedom in a kinematically redundant manipulator to plan manipulator trajectories to minimize base reactions. A global approach was developed for minimizing the magnitude of the base reactions for kinematically redundant manipulators which integrates the Partitioned Jacobian method of redundancy resolution, a 4-3-4 joint-trajectory representation and the minimization of a cost function which is the time-integral of the magnitude of the base reactions. The global approach was also compared with a local approach developed earlier for the case of point-to-point motion of a three degree-of-freedom planar manipulator with one redundant degree-of-freedom. The results show that the global approach is more effective in reducing and smoothing the base force while the local approach is superior in reducing the base moment.

Chung, C. L.↗

DOE OSTI2025

Roadmap for Assessing Fuel Reprocessing in Fluoride-Based Salts

This joint report assesses the pyroprocessing of used nuclear fuel from molten fluoride salts being conducted between Idaho National Laboratory and Argonne National Laboratory. The goal of this report is to identify the research and development gaps needed to reduce the technical risks of extending pyroprocessing technologies and unit operations to molten fluoride salts used in molten salt reactors (MSRs). Assessing and performing the tasks outlined in this report will help mitigate the technical risks and design appropriate flowsheets for reprocessing fuel and coolant salts. These suggested tasks will provide necessary data to implement the development of unit operations. Sections are highlighted to identify processes that need to be assessed and unit operations that may be used in fluoride-based chemistries. Research and development needs are listed and discussed including re-fluorination methods, electrowinning for separations, reference electrode development, materials compatibility, salt purification/re-fluorination, and waste disposition. This report will examine the technical challenges associated with pyroprocessing in molten fluoride-based salt and outline approaches to increase the technical readiness level of pyroprocessing in molten fluoride salts.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

NASA NTRS1973

Preliminary design and simulations of a Shuttle-Attached Manipulator System.

The preliminary design of a Shuttle-Attached Manipulator System is based on two arms that are articulated at shoulder, elbow, and wrist. Details of manipulator design are considered, giving attention to arm reach, velocity, acceleration, torque, joint angular travel limits, control, crew systems and man-machine interface, and telecommunications. The results of man-in-the-loop simulations show the feasibility of grappling a representative space payload from the Shuttle using a long boom manipulator system. The task, however, is sufficiently difficult to require the full concentration of one operator who should be relieved of any other tasks while performing operations with the manipulator system.

Brodie, S. B.↗

NASA NTRS1992

Robust adaptive kinematic control of redundant robots

The paper presents a general method for the resolution of redundancy that combines the Jacobian pseudoinverse and augmentation approaches. A direct adaptive control scheme is developed to generate joint angle trajectories for achieving desired end-effector motion as well as additional user defined tasks. The scheme ensures arbitrarily small errors between the desired and the actual motion of the manipulator. Explicit bounds on the errors are established that are directly related to the mismatch between actual and estimated pseudoinverse Jacobian matrix, motion velocity and the controller gain. It is shown that the scheme is tolerant of the mismatch and consequently only infrequent pseudoinverse computations are needed during a typical robot motion. As a result, the scheme is computationally fast, and can be implemented for real-time control of redundant robots. A method is incorporated to cope with the robot singularities allowing the manipulator to get very close or even pass through a singularity while maintaining a good tracking performance and acceptable joint velocities. Computer simulations and experimental results are provided in support of the theoretical developments.

Tarokh, M.↗

DOE OSTI2025

Low-Cost Sulfur Thermal Storage for Solar Industrial Process Heat Applications

Industrial process heat (IPH) is one of the largest energy demands in U.S., representing about 10% of all domestic energy consumption. Fuel costs to generate this industrial process heat are generally a top three cost for industry, a major component in American manufacturing competitiveness. Roughly 60% of US IPH demand (about 6,500 TBtu annually) falls in the medium-temperature range of 100–250 °C. While concentrated solar thermal (CST) technologies can provide a cost-effective source of heat in this temperature range, solar intermittency limits their adoption in industries that operate 24/7. Element 16 Technologies, Inc. developed a low-cost sulfur thermal energy storage (TES) technology to bridge this gap by capturing excess solar heat during the day and dispatching it reliably during non-solar hours. The core innovation is the use of sulfur, an abundant, industrial waste byproduct that costs ten times less than molten salt used in commercial TES systems. The overall goal of the project was to advance the design and development of molten sulfur TES to a manufacturing-relevant prototype stage for solar industrial process heat applications, while establishing and validating a realistic pathway to commercial success. Key tasks included corrosion and mechanical durability testing to identify cost-effective materials, design investigations using physics-based simulation tools, techno-economic evaluations of system lifetime costs, and pilot-scale testing for performance verification. Corrosion testing of steel alloys under cyclic molten sulfur conditions showed that austenitic stainless steels in the 300 series performed particularly well, with no structural degradation of welds or joints. Thermal cyclic testing of pilot sulfur TES units up to 1.5 MWh quantified charge/discharge rates, heat losses, round-trip efficiency and validated the system's capability to operate effectively under intermittent charging conditions. A techno-economic model, informed by sulfur TES performance model validated using pilot test data, showed that hybrid solar+sulfur TES+NG boiler systems are economically competitive with incumbent natural gas boilers for multiple locations in the southwest US. In summary, this project established molten sulfur TES as a technically viable pathway to improve economic competitiveness of American manufacturing by lowering the cost of solar industrial process heat.

14 SOLAR ENERGY↗

DOE OSTI2021

Predicting Thermal Performance of an Enhanced Geothermal System From Tracer Tests in a Data Assimilation Framework

Abstract Predicting the thermal performance of an enhanced geothermal system (EGS) requires a comprehensive characterization of the underlying fracture flow patterns from practically available data such as tracer data. However, due to the inherent complexities of subsurface fractures and the generally insufficient geological/geophysical data, interpreting tracer data for fracture flow characterization and thermal prediction remains a challenging task. The present study aims to tackle the challenge by leveraging a data assimilation method to maximize the utilization of information inherently contained in tracer data, and meanwhile maintain the flexibility to handle various uncertainties. A tracer data interpretation framework was proposed with the following three components integrated: (a) We use principal component analysis (PCA) to reduce the dimensionality of model parameter space. (b) We use ES‐MDA (ensemble smoother with multiple data assimilation) to invert for fracture aperture/flow fields and obtain posterior model ensembles for uncertainty quantification. Various data types are assimilated jointly to improve the predictive ability of the posterior ensemble. (c) The inverted fracture aperture fields are then incorporated into reservoir models to predict thermal performance. We developed a field‐scale EGS model to verify the ability of the framework to characterize highly heterogeneous fracture aperture/flow fields and predicting thermal performance. We also applied the framework to a mesoscale field experiment to demonstrate its potential application in real‐world geothermal reservoirs. The results indicate that the proposed framework can effectively retrieve fracture flow information from tracer data for thermal prediction and uncertainty quantification, and thus provide informative guidance for EGS optimization and risk management.

15 GEOTHERMAL ENERGY↗

DOE OSTI2012

Development of Compositional Relationships for a Glassy Slag Material for Municipal Waste Residues Resulting from a Gasification Process.

Air Products (AP) is developing a technology that uses plasma-enhanced gasification to create syngas from municipal solid waste (MSW), for the purpose of generating electricity at a large scale. The inorganic components in the MSW need to form a glassy slag that flows easily through the bed material in the gasifier. Air Products has tasked the Savannah River National Laboratory (SRNL) – a leader in development of glassy materials technologies to support Department of Energy (DOE) missions in environmental management, nuclear security, and energy security – to improve the properties and performance of the glassy material produced from MSW gasification. The objectives of this study are to define an acceptable composition range over which the glassy slag can be produced while still meeting leaching (or durability) requirements as well as to advance the understanding of the fate of trace metals originally present in the MSW. The FY12 CRADA defined six tasks for the SRNL and Air Products joint effort.

09 BIOMASS FUELS↗