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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.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

2015 Summer Design Challenge: Team A&E (2241) Additively Manufactured Discriminator.

Current discriminator designs are based on historical designs and traditional manufacturing methods. The goal of this project was to form non-traditional groups to create novel discriminator designs by taking advantage of additive manufacturing. These designs would expand current discriminator designs and provide insight on the applicability of additive manufacturing for future projects. Our design stretched the current abilities of additive manufacturing and noted desired improvements for the future. Through collaboration with NSC, we noted several additional technologies which work well with additive manufacturing such as topology optimization and CT scanning and determined how these technologies could be improved to better combine with additive manufacturing.

42 ENGINEERING↗
DOE OSTI2017

Modeling the temporal dynamics of nonstructural carbohydrate pools in forest trees

Trees store carbohydrates, in the form of sugars and starch, as reserves to be used to power both future growth as well as to support day-to-day metabolic functions. These reserves are particularly important in the context of how trees cope with disturbance and stress—for example, as related to pest outbreaks, wind or ice damage, and extreme climate events. In this project, we measured the size of carbon reserves in forest trees, and determined how quickly these reserves are used and replaced—i.e., their “turnover time”. Our work was conducted at Harvard Forest, a temperate deciduous forest in central Massachusetts. Through field sampling, laboratory-based chemical analyses, and allometric modeling, we scaled these measurements up to whole-tree NSC budgets. We used these data to test and improve computer simulation models of carbon flow through forest ecosystems. Our modeling focused on the mathematical representation of these stored carbon reserves, and we examined the sensitivity of model performance to different model structures. This project contributes to DOE’s goal to improve next-generation models of the earth system, and to understand the impacts of climate change on terrestrial ecosystems.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Reactor Physics Experiment NEA Benchmark Possibilities for Measurements at ORCEF and Other DOE Facilities

This report documents a wide variety of critical and subcritical reactor physics measurements that could be included in the Nuclear Energy Agency (NEA) International Handbook of Evaluated Reactor Physics Benchmark Experiments. The experiments were performed by John T. Mihalczo and coworkers at many (8) DOE facilities including the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF between 1958 and 1975), Los Alamos National Laboratory, Pacific Northwest National Laboratory, and Babcock and Wilcox at Lynchburg, Virginia, and the Y-12 National Security Complex (the latter between 1975 and up to 2006). This report lists the various measurement programs and a limited description of the reactor physics measurement that were performed in each that could be benchmarks. Some criticality safety measurements at these facilities have already been documented in the NEA International Handbook of evaluated Criticality Safety Benchmark Experiments. Some of these reactor physics measurements have also been documented in the literature and this document give a complete list of references for which John T. Mihalczo was an author or co-author. The experiments are divided into four classes: critical experiments only, critical and subsequent subcritical experiments, subcritical experiments at critical facilities, and subcritical measurements performed in material balance areas of the Y-12 National Security Complex (NSC) and other facilities. Because of the high cost and large amount of facility time related to these measurements, it is very cost-effective to mine the existing data to produce NEA reactor physics benchmarks. The information for many of these measurements is documented in critical experiment and subcritical experiment logbooks at the International Criticality Safety Benchmark Program at Idaho National Laboratory and in Laboratory Records at Oak Ridge National laboratory.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

Simulation of a rapid compression machine for evaluation of ignition chemistry and soot formation using gasoline/ethanol blends

Due to the projected decline of demand for gasoline in light duty engines and the advent of ethanol as a green fuel, the use of gasoline/ethanol blend fuels in heavy duty applications are being investigated as they are projected to have lower cost and lower lifecycle green house gas (GHG) emissions. In heavy duty engines, the primary mode of combustion is mixing controlled combustion where wide range of mixture conditions (equivalence ratio) exist. Soot emissions of these fuels in richer conditions are not well understood. The goal of this research is to evaluate some commercially available soot modeling codes for the particulate matter emissions from gasoline/ethanol fuel blends, especially at fuel rich conditions. A Rapid Compression Machine (RCM) is modeled in a three-dimensional numerical simulation using CONVERGE computational software using a reduced chemical kinetic mechanism with SAGE chemistry solver and a RANS k-ϵturbulence model with a sector model including the creviced piston. The creviced piston is used in the experimental setup to reduce boundary layer effects and to maintain a homogeneous core in the reaction cylinder. Computational fluid dynamics simulations are conducted for different gasoline-ethanol fuel blends from E10 (10% ethanol v/v) to E100. The fuel blend is modeled as a surrogate mixture of toluene, iso-octane, n-heptane for gasoline content, and ethanol. The computational results were validated against experimental results using pressure measurements and laser extinction diagnostics. Different soot models are investigated to evaluate their capability of predicting the sooting tendencies of fuel blends, especially in richer conditions experienced during mixing-controlled combustion. The experimental combustion characteristics such as the ignition delay of different blends of fuel are reasonably well predicted. The Particulate Size Mimic (PSM) model accurately predicts the soot generation characteristics of the different fuels, but the Hiroyasu-NSC model falls short in this regard. For accurate prediction of soot with the PSM model, the thermodynamic conditions during combustion must be accurately modeled. While the current computational modeling tools can produce accurate results for the prediction of particulate matter emissions, there is much work to be done in improving our understanding of the underlying fundamental processes.

Energy & Fuels↗
DOE OSTI2016

THE HISTORY OF TIDAL DISRUPTION EVENTS IN GALACTIC NUCLEI

The tidal disruption of a star by a massive black hole (MBH) is thought to produce a transient luminous event. Such tidal disruption events (TDEs) may play an important role in the detection and characterization of MBHs, and in probing the properties and dynamics of their nuclear stellar cluster (NSC) hosts. Previous studies estimated the recent rates of TDEs in the local universe. However, the long-term evolution of the rates throughout the history of the universe has been little explored. Here we consider TDE history, using evolutionary models for the evolution of galactic nuclei. We use a 1D Fokker–Planck approach to explore the evolution of MBH-hosting NSCs, and obtain the disruption rates of stars during their evolution. We complement these with an analysis of TDE history based on N -body simulation data, and find them to be comparable. We consider NSCs that are built up from close-in star formation (SF) or from far-out SF/cluster-dispersal, a few pc from the MBH. We also explore cases where primordial NSCs exist and later evolve through additional SF/cluster-dispersal processes. We study the dependence of the TDE history on the type of galaxy, as well as the dependence on the MBH mass. These provide several scenarios, with a continuous increase of the TDE rates over time for cases of far-out SF and a more complex behavior for the close-in SF cases. Finally, we integrate the TDE histories of the various scenarios to provide a total TDE history of the universe, which can be potentially probed with future large surveys (e.g., LSST).

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

AGN Activity in Nucleated Galaxies as Measured by Chandra

Motivated by theoretical expectations that nuclear star clusters (NSCs) in galactic centers may provide a favorable environment for supermassive black holes to form and/or efficiently grow, we set out to measure the fraction of nearby nucleated galaxies that also host an active galactic nucleus. We targeted a distance-limited sample of 98 objects with the Chandra X-ray Telescope, down to a uniform X-ray luminosity threshold of ∼10{sup 38} erg s{sup −1}. The sample is composed of 47 late-types and 51 early-types, enabling us to further investigate the active fraction as a function of galactic morphology. After correcting for contamination to the nuclear X-ray signal from bright X-ray binaries, we measure an active fraction f=11.2%{sub −4.9}{sup +7.4} (1σ C.L.) across the whole sample, in agreement with previous estimates based on a heterogeneous combination of optical, X-ray, and radio diagnostics, by Seth et al. After accounting for the different stellar mass distributions in our samples, we find no statistically significant difference in the active fraction of early- versus late-type nucleated galaxies, with f=10.6%{sub −4.9}{sup +11.9} and 10.8%{sub −6.3}{sup +11.3}, respectively. For the early-type nucleated galaxies, we are able to carry out a controlled comparison with a parent sample of non-nucleated galaxies covering the same stellar mass range, again finding no statistically significant difference in the active fraction. Taken at face value, our findings suggest that the presence of an NSC does not facilitate or enhance accretion-powered emission from a nuclear supermassive black hole. This is true even for late-type nucleated galaxies, home to bluer NSCs and arguably larger gas reservoirs.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1981

Use and applicability of the vegetation component of the national site classification system

Existing vegetation on a site in Sumter National Forest, South Carolina was classified using high altitude aerial optical bar color infrared photography in an effort to determine if the National Site Classification (NSC) system could be used in the heterogeneously forested southeastern United States where it had not previously been used. Results show that the revised UNESCO international classification and mapping of vegetation system, as incorporated into the NSCS, is general enough at the higher levels and specific enough at the lower levels to adequately accommodate densely forested, heterogeneous areas as well as the larger, more homogeneous regions of the Pacific Northwest. The major problem is of existing vegetation versus natural vegetation.

Clark, C. A.↗
NASA NTRS1991

Space transfer vehicle concepts and requirements. Volume 1: Executive summary

The objectives of the Space Transfer Vehicle (STV) Concepts and Requirements studies were to provide sensitivity data on usage, economics, and technology associated with new space transportation systems. The study was structured to utilize data on the emerging launch vehicles, the latest mission scenarios, and Space Exploration Initiative (SEI) payload manifesting and schedules, to define a flexible, high performance, cost effective, evolutionary space transportation system for NASA. Initial activities were to support the MSFC effort in the preparation of inputs to the 90 Day Report to the National Space Council (NSC). With the results of this study establishing a point-of-departure for continuing the STV studies in 1990, additional options and mission architectures were defined. The continuing studies will update and expand the parametrics, assess new cargo and manned ETO vehicles, determine impacts on the redefined Phase 0 Space Station Freedom, and to develop a design that encompasses adequate configuration flexibility to ensure compliance with on-going NASA study recommendations with major system disconnects. In terms of general requirements, the objectives of the STV system and its mission profiles will address crew safety and mission success through a failure-tolerant and forgiving design approach. These objectives were addressed through the following: engine-out capability for all mission phases; built-in-test for vehicle health monitoring to allow testing of all critical functions such as, verification of lunar landing and ascent engines before initiating the landing sequence; critical subsystems will have multiple strings for redundancy plus adequate supplies of onboard spares for removal and replacement of failed items; crew radiation protection; and trajectories that optimize lunar and Mars performance and flyby abort capabilities.

Source record↗
NASA NTRS1996

Fact Sheet: National Space Policy

For over three decades, the United States has led the world in the exploration and use of outer space. Our achievements in space have inspired a generation of Americans and people throughout the world. We will maintain this leadership role by supporting a strong, stable, and balanced national space program that serves our goals in national security, foreign policy, economic growth, environmental stewardship, and scientific and technical excellence. Access to and use of space are central for preserving peace and protecting US national security as well as civil and commercial interests. The United States will pursue greater levels of partnership and cooperation in national and international space activities and work with other nations to ensure the continued exploration and use of outer space for peaceful purposes. The goals of the US space program are to: (a) Enhance knowledge of the Earth, the solar system, and the universe through human and robotic exploration; (b) Strengthen and maintain the national security of the United States; (c) Enhance the economic competitiveness and scientific and technical capabilities of the United States; (d) Encourage State, local, and private sector investment in, and use of, space technologies; (e) Promote international cooperation to further US domestic, national security, and foreign policies. The United States is committed to the exploration and use of outer space by all nations for peaceful purposes and for the benefit of all humanity. "Peaceful purposes" allow defense and intelligence-related activities in pursuit of national security and other goals. The United States rejects any claims to sovereignty by any nation over outer space or celestial bodies, or any portion thereof, and rejects any limitations on the fundamental right of sovereign nations to acquire data from space. The United States considers the space systems of any nation to be national property with the right of passage through and operations in space without interference. Purposeful interference with space systems shall be viewed as an infringement on sovereign rights. The US Government will maintain and coordinate separate national security and civil space systems where differing needs dictate. All actions undertaken by agencies and departments in implementing the national space policy shall be consistent with US law, regulations, national security requirements, foreign policy, international obligations, and nonproliferation policy. The National Science and Technology Council (NSTC) is the principal forum for resolving issues related to national space policy. As appropriate, the NSTC and NSC will co-chair policy process. This policy will be implemented within the overall resource and policy guidance provided by the President.

Source record↗
NASA NTRS2003

Soot Nanostructure And Its Impact Upon The O2 Oxidation Rate

Studies of soot oxidation have ranged from in situ flame studies to shock tubes to flow reactors. Each of these systems possesses particular advantages and limitations related to temperature, time and chemical environments. Despite the aforementioned differences, these soot oxidation investigations share three striking features. First and foremost is the wide variation in the rates of oxidation. Reported oxidation rates vary by factors of +6 to - 20 relative to the Nagle Strickland-Constable (NSC) rate for graphite oxidation [3]. Rate variations are not surprising, as the temperatures, residence times, types of oxidants and methods of oxidation differ from study to study. Nevertheless, a valid explanation for rate differences of this magnitude has yet to be presented.

Wal, Randy L. Vander↗
NASA NTRS1996

Experiences From NASA/Langley's DMSS Project

There is a trend in institutions with high performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high speed network. The Distributed Mass Storage System (DMSS) Project at the NASA Langley Research Center (LaRC) has placed such a system into production use. This paper will present the experiences, both good and bad, we have had with this system since putting it into production usage. The system is comprised of: 1) National Storage Laboratory (NSL)/UniTree 2.1, 2) IBM 9570 HIPPI attached disk arrays (both RAID 3 and RAID 5), 3) IBM RS6000 server, 4) HIPPI/IPI3 third party transfers between the disk array systems and the supercomputer clients, a CRAY Y-MP and a CRAY 2, 5) a "warm spare" file server, 6) transition software to convert from CRAY's Data Migration Facility (DMF) based system to DMSS, 7) an NSC PS32 HIPPI switch, and 8) a STK 4490 robotic library accessed from the IBM RS6000 block mux interface. This paper will cover: the performance of the DMSS in the following areas: file transfer rates, migration and recall, and file manipulation (listing, deleting, etc.); the appropriateness of a workstation class of file server for NSL/UniTree with LaRC's present storage requirements in mind the role of the third party transfers between the supercomputers and the DMSS disk array systems in DMSS; a detailed comparison (both in performance and functionality) between the DMF and DMSS systems LaRC's enhancements to the NSL/UniTree system administration environment the mechanism for DMSS to provide file server redundancy the statistics on the availability of DMSS the design and experiences with the locally developed transparent transition software which allowed us to make over 1.5 million DMF files available to NSL/UniTree with minimal system outage

Source record↗
DOE OSTI2014

Human Reliability Program Workshop

A Human Reliability Program (HRP) is designed to protect national security as well as worker and public safety by continuously evaluating the reliability of those who have access to sensitive materials, facilities, and programs. Some elements of a site HRP include systematic (1) supervisory reviews, (2) medical and psychological assessments, (3) management evaluations, (4) personnel security reviews, and (4) training of HRP staff and critical positions. Over the years of implementing an HRP, the Department of Energy (DOE) has faced various challenges and overcome obstacles. During this 4-day activity, participants will examine programs that mitigate threats to nuclear security and the insider threat to include HRP, Nuclear Security Culture (NSC) Enhancement, and Employee Assistance Programs. The focus will be to develop an understanding of the need for a systematic HRP and to discuss challenges and best practices associated with mitigating the insider threat.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2014

Mercury Source Zone Identification using Soil Vapor Sampling and Analysis

Development and demonstration of reliable measurement techniqes that can detect and help quantify the nature and extent of elemental mercury (Hg(0)) in the subsurface are needed to reduce certainties in the decision making process and increase the effectiveness of remedial actions. We conducted field tests at the Y-12 National Security Complex (NSC) in Oak Ridge, TN, to determine if sampling and analysis of Hg(0) vapors in the shallow subsurface (<0.3 m depth) can be used to as an indicator of the location and extent of Hg(0) releases in the subsurface. We constructed a rigid PVC pushprobe assembly, which was driven into the ground. Soil gas samples were collected through a sealed inner tube of the assembly and analyzed immediately in the field with a Lumex and/or Jerome Hg(0) analyzer. Time-series sampling showed that Hg vapor concentrations were fairly stable over time suggesting that the vapor phase Hg(0) was not being depleted and that sampling results were not dependent on the soil gas purge volume. Hg(0) vapor data collected at over 200 pushprobe locations at 3 different release sites correlated well to areas of known Hg(0) contamination. Vertical profiling of Hg(0) vapor concentrations conducted at 2 locations provided information on the vertical distribution of Hg(0) contamination in the subsurface. We concluded from our studies that soil gas sampling and analysis can be conducted rapidly and inexpensively at a large scale to help identify areas contaminated with Hg(0).

Watson, David B↗
DOE OSTI2019

Nuclear Criticality Safety Lessons Learned in the Design of the Uranium Processing Facility at the Y-12 National Security Complex

The Uranium Processing Facility (UPF) is being built by the National Nuclear Security Administration (NNSA) to replace aging uranium processes at the Y-12 National Security Complex (Y-12 NSC) in Oak Ridge Tennessee. Specifically, the processes housed in building 9212 are being replaced as this facility dates to the World War II Manhattan Project days of Y-12. When the UPF Project is completed it will consist of three main facilities along with several support facilities. The Main Processing Building (MPB) will house oxide production and metal casting operations. The Salvage and Accountability Building (SAB) will house wet chemistry operations (examples include recovery evaporation and calcination of solutions). The Personnel Support Building will be connected to both the SAB and the MPB and will serve as a transition facility for materials and personnel between the two. The MPB will also be connected to the Highly Enriched Uranium Materials Storage Facility (HEUMF) via a connector (HCON) to permit transfers from storage into UPF directly. This paper will summarize some of the more important lessons learned for the NCS practitioner working in a design environment rather than in a production or experimental environment. As the Chief NCS Engineer for the UPF Project I have been responsible for ensuring the technical evaluations produced on the project are high quality, technically accurate, and conform to the Y-12 NCS Program expectations. Ensuring nuclear criticality safety for processes that do not yet exist in reality is a challenge very different than that of ensuring subcriticality for processes in an operating facility. The biggest difference being that in design space – everything is imaginary whereas in the operating facility you have the benefit of being able to go out and look at the equipment and interview the operators. Ensuring that Nuclear Criticality Safety is integrated into design is a process that requires constant communication between the NCS staff and the broader engineering design team. Until the facility is constructed – nothing is physically stable and so rigorous documentation of decisions – to include any assumptions – is necessary to minimize errors. Non-NCS engineers will not understand the hazard or the physics of nuclear criticality. It is up to the NCS staff to provide training and communication to the team. The NCS staff must be patient and prepared to explain themselves many times and be as flexible as possible.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2019

Benchmark Study on Innovative Fuels for Fast Reactors with fuel performance codes

The Working Party on the Scientific Issues of the Fuel Cycle (WPFC) has been established under the auspices of the Nuclear Energy Agency (NEA) Nuclear Science Committee (NSC), to co-ordinate scientific activities regarding various existing and advanced nuclear fuel cycles, including advanced reactor systems, associated chemistry and flowsheets, development and performance of fuels and materials, accelerators and spallation targets. Various expert groups were established to cover the above-mentioned topics. Within the WPFC, the Expert Group on Innovative Fuels (EGIF) was created with the objective of conducting joint and comparative studies to support the development of innovative fuels such as homogeneous and heterogeneous fuels, ADS fuels, and oxide, metal, nitride and carbide fuels, all of which can be implemented in advanced nuclear fuel cycles with fast reactors. The scope of the expert group covers innovative fuel fabrication techniques, irradiation performance of innovative fuels, characterisation and post-irradiation examination methods and predictive codes for innovative fuel fabrication and performance. This report presents the results of a benchmark study on innovative fuels for fast reactors using fuel performance codes. Irradiation results were shared among participants, and code calculations were performed to gain further insights on the fuel behaviour. Each participating institution used its own fuel performance code. Code to code and code to experiment comparisons are expected to provide data and improve understanding on the effects of minor actinides on fuel behaviour. In conclusion, the need for improvement of codes will be evaluated and the needs for new experimental data will be identified in order to finalise the code validation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2013

Coupling and Testing the Fate and Transport of Heavy Metals and Other Ionic Species in a Groundwater Setting at Oak Ridge, TN - 13498

Historical data show that heavy metals (including mercury) were released from Y -12 National Security Complex (NSC) at Oak Ridge, Tennessee, to the surrounding environments during its operation in 1950's. Studies have also shown that metals accumulated in the soil, rock, and groundwater, and are, at the present time, sources of contamination to nearby rivers and creeks (e.g., East Fork Poplar Creek, Bear Creek). For instance, mercury (Hg), zinc (Zn), cadmium (Cd) and lead (Pb) have been found and reported on the site groundwater. The groundwater type at the site is Ca-Mg-HCO{sub 3}. This paper presents a modeling application of PHREEQC, a model that simulates geochemical processes and couples them to flow and transport settings. The objective was to assess the capability of PHREEQC to simulate the transport of ionic species in groundwater at Oak Ridge, Tennessee; data were available from core holes and monitoring wells over a 736-m distance, within 60-300 m depths. First, predictions of the transport of major ionic species (i.e., Ca{sup 2+} and Mg{sup 2+}) in the water were made between monitoring wells and for GW-131. Second, the model was used to assess hypotheses under two scenarios of transport for Zn, Cd, Pb and Hg, in Ca-Mg-HCO{sub 3} water, as influenced by the following solid-liquid interactions: a) the role of ion exchange and b) the role of both ion exchange and sorption, the latter via surface complexation with Fe(OH){sub 3}. The transport scenario with ion exchange suggests that significant ion exchange is expected to occur for Zn, Cd and Pb concentrations, with no significant impact on Hg, within the first 100 m. Predictions match the expected values of the exchange coefficients relative to Ca{sup 2+} and Mg{sup 2+} (e.g., K{sub Ca/Zn} = K{sub Ca/Cd} > K{sub Ca/Pb} > K{sub Ca/Hg}). The scenario with both ion exchange and sorption does affect the concentrations of Zn and Cd to a small extent within the first 100 m, but does more meaningfully reduce the concentration of Pb, within the same distance, and also decreases the concentration of Hg in between core holes. Analysis of the above results, in the light of available literature on the ions of this study, does fundamentally support the capability of PHREEQC to predict the transport of major ions in a groundwater setting; it also generally supports the hypothesized role of ion exchange and sorption. The results indicate the potential of the model as a tool in the screening, selection and monitoring of remediation technologies for contaminated groundwater sites. (authors)

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

OECD/NEA Ongoing activities related to the nuclear fuel cycle

As part of its role in encouraging international collaboration, the OECD Nuclear Energy Agency is coordinating a series of projects related to the Nuclear Fuel Cycle. The Nuclear Science Committee (NSC) Working Party on Scientific Issues of the Nuclear Fuel Cycle (WPFC) comprises five different expert groups covering all aspects of the fuel cycle from front to back-end. Activities related to fuels, materials, physics, separation chemistry, and fuel cycles scenarios are being undertaken. By publishing state-of-the-art reports and organizing workshops, the groups are able to disseminate recent research advancements to the international community. Current activities mainly focus on advanced nuclear systems, and experts are working on analyzing results and establishing challenges associated to the adoption of new materials and fuels. By comparing different codes, the Expert Group on Advanced Fuel Cycle Scenarios is aiming at gaining further understanding of the scientific issues and specific national needs associated with the implementation of advanced fuel cycles. At the back end of the fuel cycle, separation technologies (aqueous and pyrochemical processing) are being assessed. Current and future activities comprise studies on minor actinides separation and post Fukushima studies. Regular workshops are also organized to discuss recent developments on Partitioning and Transmutation. In addition, the Nuclear Development Committee (NDC) focuses on the analysis of the economics of nuclear power across the fuel cycle in the context of changes of electricity markets, social acceptance and technological advances and assesses the availability of the nuclear fuel and infrastructure required for the deployment of existing and future nuclear power. The Expert Group on the Economics of the Back End of the Nuclear Fuel Cycle (EBENFC), in particular, is looking at assessing economic and financial issues related to the long term management of spent nuclear fuel. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Utilization of GIS technology to support development of flow and contaminant fate and transport models at US DOE sites - 15457

U.S. Department of Energy (DOE) sites have accumulated years of data and millions of spatial and temporal records related to the hydrological cycle, contaminant transport, and parameters of remediation technologies. In addition, numerical models which use field monitoring data to help understand flow and transport produce gigabytes of computed spatial and temporal data for each computation node. There is a need therefore for an advanced spatial data structure that can be used to address the management, processing, and analysis of spatial and temporal numerical modeling data derived from multiple sources. This can be accomplished using a geo-database. The development of an ArcSDE geo-database facilitates the centralized storage, backup, accessibility, organization, and management of model configuration and computed simulation data, putting it into a structured, coherent, and logical computer-supported system. GIS data processing and automation would enable faster and hence more complex analyses of field test data. The Applied Research Center (ARC) at Florida International University (FIU) has provided analysis of flow and transport for several watersheds at DOE's Oak Ridge Reservation (ORR), including East Fork Poplar Creek (EFPC), Upper EFPC in the Y-12 National Security Complex area (Y-12 NSC) and White Oak Creek (WOC). Integrated surface and subsurface flow, fate and transport models were developed to provide analysis of contaminant patterns within each watershed. In addition, digital monitoring data available from the Oak Ridge Environmental Information System (OREIS) related to mercury (Hg) contamination and remediation within these watersheds was used for calibration and verification of the model. Experimental studies were also carried out which provided kinetic and equilibrium data about important parameters related to Hg transport, speciation and methylation/demethylation kinetics within the watershed. Geographic Information Systems (GIS) technology was employed to support the modeling work through storage and geo-processing of spatial and temporal data required by the models and to produce hydrogeological maps for visualization. An ArcGIS geo-database was developed for centralized storage and management of experimental and computed model data and its capabilities were extended over the years using tools such as ModelBuilder combined with Python scripting to automate repetitive tasks, perform statistical analyses and generate maps and reports. The hydrologic geo-database model developed possesses a structure that enables linkage with scalable hydrologic modeling tools/applications to model hydrologic systems, and in this case, enables the testing of the potential impacts of various remediation scenarios on the ORR watersheds. The ArcSDE geo-database can also be used to automate and simplify the process of calling stored GIS and time series data. This geo-database can serve as a tool for contaminant flow and transport analyses which require large amounts of high-quality spatial and temporal data in order to ensure reliability and validity of modeling results. The existing geo-database structure developed for the hydrological modeling at ORR was designed to be replicable for application at other DOE sites. An investigation of downloadable free/open source GIS software along with required security protocols to facilitate online querying of the database was also conducted to determine methods by which project-derived data can be more easily shared with other project stakeholders such as DOE personnel and site contractors. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗