Designs, Parameters and Problems in the Associated Cooled Equipment of a High Purity Low Conductivity Water System Rated at 7500 GPM and 25.5 Megawatts
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Brunk, W.↗
SEARCH · Engineering Papers
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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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A Parameterization of the Cloud Scattering Polarization Signal Derived From GPM Observations for Microwave Fast Radative Transfer Models
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54 ENVIRONMENTAL SCIENCES↗
300 GPM Solids Removal System A True Replacement for Back Flushable Powdered Filter Systems - 13607
The EnergySolutions Solids Removal System (SRS) utilizes stainless steel cross-flow ultra-filtration (XUF) technology which allows it to reliably remove suspended solids greater than one (1) micron from liquid radwaste streams. The SRS is designed as a pre-treatment step for solids separation prior to processing through other technologies such as Ion Exchange Resin (IER) and/or Reverse Osmosis (RO), etc. Utilizing this pre-treatment approach ensures successful production of reactor grade water while 1) decreasing the amount of radioactive water being discharged to the environment; and 2) decreasing the amount of radioactive waste that must ultimately be disposed of due to the elimination of spent powdered filter media. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Validation and Error Characterization for the Global Precipitation Measurement
The Global Precipitation Measurement (GPM) is an international effort to increase scientific knowledge on the global water cycle with specific goals of improving the understanding and the predictions of climate, weather, and hydrology. These goals will be achieved through several satellites specifically dedicated to GPM along with the integration of numerous meteorological satellite data streams from international and domestic partners. The GPM effort is led by the National Aeronautics and Space Administration (NASA) of the United States and the National Space Development Agency (NASDA) of Japan. In addition to the spaceborne assets, international and domestic partners will provide ground-based resources for validating the satellite observations and retrievals. This paper describes the validation effort of Global Precipitation Measurement to provide quantitative estimates on the errors of the GPM satellite retrievals. The GPM validation approach will build upon the research experience of the Tropical Rainfall Measuring Mission (TRMM) retrieval comparisons and its validation program. The GPM ground validation program will employ instrumentation, physical infrastructure, and research capabilities at Supersites located in important meteorological regimes of the globe. NASA will provide two Supersites, one in a tropical oceanic and the other in a mid-latitude continental regime. GPM international partners will provide Supersites for other important regimes. Those objectives or regimes not addressed by Supersites will be covered through focused field experiments. This paper describes the specific errors that GPM ground validation will address, quantify, and relate to the GPM satellite physical retrievals. GPM will attempt to identify the source of errors within retrievals including those of instrument calibration, retrieval physical assumptions, and algorithm applicability. With the identification of error sources, improvements will be made to the respective calibration, assumption, or algorithm. The instrumentation and techniques of the Supersites will be discussed. The GPM core satellite, with its dual-frequency radar and conically scanning radiometer, will provide insight into precipitation drop-size distributions and potentially increased measurement capabilities of light rain and snowfall. The ground validation program will include instrumentation and techniques commensurate with these new measurement capabilities.
Bidwell, Steven W.↗
NASA's Global Precipitation Mission Ground Validation Segment
NASA is designing a Ground Validation Segment (GVS) as one of its contributions to the Global Precipitation Measurement (GPM) mission. The GPM GVS provides an independent means for evaluation, diagnosis, and ultimately improvement of the GPM spaceborne measurements and precipitation products. NASA's GPM GVS concept calls for a combination of direct observations executed within a Multidimensional Observing Volume (MOV) and model-based analyses executed by a Satellite Simulator Model (SSM). The MOV consists of ground-based instruments that measure local surface and atmospheric properties required for GPM validation. The SSM utilizes MOV measurements in a forward numerical model. The goal of the SSM forward modeling is calculation of the following properties: top-of-atmosphere microwave radiative quantities to within sensor noise of those measured by the GPM Core Satellite, precipitation quantities identical to those generated by the standard GPM precipitation retrieval algorithms, and quantitative/objective error estimates of both sets of quantities. At present, the GVS is in the early design stage and various scenarios have been generated to assess how it will be used in the GPM era. The GPM GVS will be operational in the year prior to the launch of the GPM core satellite, which has a launch date scheduled for December 2010.
GVS (GROUND VALIDATION SEGMENT)↗
Graphene-polyelectrolyte multilayer membranes with tunable structure and internal charge
One great advantage of graphene-polyelectrolyte multilayer (GPM) membranes is their tunable structure and internal charge for improved separation performance. In this study, we synthesized GO-dominant GPM membrane with internal negatively-charged domains, polyethyleneimine (PEI)-dominant GPM membrane with internal positively-charged domains and charge-balanced dense/loose GPM membranes by simply adjusting the ionic strength and pH of the GO and PEI solutions used in layer-by-layer membrane synthesis. A combined system of quartz crystal microbalance with dissipation (QCM-D) and ellipsometry was used to analyze the mass deposition, film thickness, and layer density of the GPM membranes. The performance of the GPM membranes were compared in terms of both permeability and selectivity to determine the optimal membrane structure and synthesis strategy. One effective strategy to improve the GPM membrane permeability-selectivity tradeoff is to assemble charge-balanced dense membranes under weak electrostatic interactions. This balanced membrane exhibits the highest MgCl 2 selectivity (~86%). Another effective strategy for improved cation removal is to create PEI-dominant membranes that provide internal positively-charged barrier to enhance cation selectivity without sacrificing water permeability. Finally, these findings shine lights on the development of a systematic approach to push the boundary of permeability-selectivity tradeoff for GPM membranes.
42 ENGINEERING↗
IMERG Multi-Satellite Products Across Two Decades
The Version 06 Global Precipitation Measurement (GPM) mission products were completed over the last year, capping five years of development since the launch of the GPM Core Observatory, and covering the joint Tropical Rainfall Measuring Mission (TRMM) and GPM eras with consistently processed algorithms. The U.S. GPM team’s Integrated Multi-satellitE Retrievals for GPM (IMERG) merged precipitation product enforces a consistent intercalibration for all precipitation products computed from individual satellites with the TRMM and GPM Core Observatory sensors as the TRMM- and GPM-era calibrators, respectively, and incorporates monthly surface gauge data in the Final (research) product. Mid-latitude calibrations during the TRMM era necessarily are more approximate because TRMM only covered the latitude band 35°N-S, while GPM covers 65°N-S. Starting in V06, IMERG employs precipitation motion vectors (used to drive the quasi-Lagrangian interpolation, or “morphing”) that are computed by tracking the vertically integrated vapor as analyzed in MERRA2 and GEOS FP. This approach covers the entire globe, expanding coverage beyond the 60°N-S latitude band provided by IR-based vectors in previous versions, although we choose to mask out microwave-based precipitation over snowy/icy surfaces as unreliable. We will provide examples of performance for the V06 IMERG products, including comparison with the long-term record of GPCP and TMPA, showing higher values by about 8% in the latitude band 50°N-S over oceans; diurnal cycle, demonstrating improvement over previous versions; and daily precipitation PDFs for the entire record, showing a shift at the TRMM/GPM boundary, as well as interannual variations. These analyses have important implications for the utility of V06 IMERG data for long-record calculations. Finally, we will review the retirement of the predecessor TMPA multi-satellite dataset.
George J. Huffman↗
Electric Power Generation from Low to Intermediate Temperature Resources
This project was designed to test the concept on the Eland-Lodgepole Field near Dickinson, North Dakota in the Williston Basin. The field is in secondary-recovery water-flood and consists of 12 producing oil wells, 5 water injection wells and one disposal well. Water production at the site averages approximately 320 gallons per minute (20.2 l s-1) and the temperature is 100 ⁰C. Engineers at Ormat estimated power production potential with the existing resource to be approximately 350 kWh. Unfortunately, ownership of the field was transferred from Encore, Inc., to Denbury, Inc., within the first week of the project. After two years of discussion and planning, Denbury decided not to pursue this project due to complications with the site location and its proximity to Patterson Lake. Attempts to find other partners operating in the Williston Basin were unsuccessful. Consequently, we were unable to pursue the primary objective of the project. However, during negations with Denbury and subsequent time spent contacting other potential partners, we focused on objectives 2 and 3 and developed a clear understanding of the potential for co-produced production in the Williston Basin and the best practices for developing similar projects. At least nine water bearing formations with temperatures greater than 90 ⁰C extend over areas of several 10s of km2. The total energy contained in the rock volume of those geothermal aquifers is 283.6 EJ (1 EJ = 1018 J). The total energy contained in the water volume, determined from porosities which range from 2 percent to 8 percent, is 6.8 EJ. The aquifers grouped by 10 ⁰C temperature bins (Table 1) include one or more formations due to the bowl-shape structure of the basin. Table 1. Summary of energy available in geothermal aquifers in the Williston Basin Analysis of overall fluid production from active wells, units, fields and formations in North Dakota showed that few sites co-produce sufficient fluid for significant power production with ORC technology. Average co-produced water for 10,480 wells is 3.2 gallons per minute (gpm). Even excluding the tight formations, Bakken and Three Forks, average co-produced water for the remaining 3,337 is only 5 gpm. The output of the highest producing well is 184 gpm and the average of the top 100 wells is 52 gpm. Due to the depth of the oil producing formations in the Williston Basin, typically 3 km or greater, pumps are operated slowly to prevent watering out thus total fluid production is purposefully maintained at low volumes. There remain potential possibilities for development of geothermal fluids in the Williston Basin. Unitized fields in which water production from several tens of wells is collected at a single site are good possibilities for development. Water production in the unitized fields is greater than 1000 gpm is several areas. A similar possibility occurs where infill-drilling between Bakken and Three Forks horizontal wells has created areas where large volumes of geothermal fluids are available on multi-well pads and in unitized fields. Although the Bakken produces small amounts of water, the water/oil ration is typically less than 1, the oil and water mix produced at the well head can be sent through the heat exchanger on an ORC. It is estimated that several tens of MWh of power could be generated by a distributed system of ORC engines in the areas of high-density drilling in the Bakken Formation. Finally, horizontal drilling in water bearing formations is the other possibility. Several secondary recovery water-flood projects in the basin are producing water above 100 ⁰C at rates of 300 gpm to 850 gpm. Those systems also could produce several tens of MWh of power with ORC technology. Objective 3 of the project was highly successful. The program has produced 5 PhDs, 7 MS, and 3 BS students with theses in geothermal energy. The team has involved 7 faculty in 4 different engineering and science disciplines, ChE, EE, GE, and Geol. The team has produced 26 peer-reviewed papers and 62 presentations at professional meetings. Faculty involved in the program developed five graduate level courses covering different elements in heat flow and geothermal energy that are now offered in the Harold Hamm School of Geology and Geological Engineering. Lessons learned – Keys to developing a successful project;1. Determine target formations; a. Data from oil and gas operators, state oil and gas regulatory agencies, and state geological surveys help to identify producing formations and their properties; 2. Determine the quantity of energy available in the target formations; a. A complete thermal analysis of the basin or region yields the most useful information; b. Critical data include: BHT, heat flow, stratigraphy, lithology, lithological properties, and thermal conductivity, subsurface structure; 3. Determine fluid production potential; a. State oil and gas regulatory agencies, and state geological surveys have data on oil, gas and water production. State Water Commission/Agencies have data on water quality, aquifers, and regulations; b. Consider single horizontal wells, multiple conventional wells, and unitized fields; 4. Calculate energy production capacity of each formation based on different well combination and power plant scenarios. This is a broad overview rather than a site specific analysis; 5. Research and understand the local electrical power industry. Obtain the PPA before committing to the project; 6. Work with the high-level personnel in the oil company partner. Obtain an MOU that addresses all issues in the project including what to expect if the company goes out of business, is bought out, changes management, etc; and 7. Be prepared for project delays.
15 GEOTHERMAL ENERGY↗
Measurement of Global Precipitation
The Global Precipitation Measurement (GPM) Program is an international cooperative effort whose objectives are to (a) obtain increased understanding of rainfall processes, and (b) make frequent rainfall measurements on a global basis. The National Aeronautics and Space Administration (NASA) of the United States and the Japanese Aviation and Exploration Agency (JAXA) have entered into a cooperative agreement for the formulation and development of GPM. This agreement is a continuation of the partnership that developed the highly successful Tropical Rainfall Measuring Mission (TRMM) that was launched in November 1997; this mission continues to provide valuable scientific and meteorological information on rainfall and the associated processes. International collaboration on GPM from other space agencies has been solicited, and discussions regarding their participation are currently in progress. NASA has taken lead responsibility for the planning and formulation of GPM, Key elements of the Program to be provided by NASA include a Core satellite bus instrumented with a multi-channel microwave radiometer, a Ground Validation System and a ground-based Precipitation Processing System (PPS). JAXA will provide a Dual-frequency Precipitation Radar for installation on the Core satellite and launch services. Other United States agencies and international partners may participate in a number of ways, such as providing rainfall measurements obtained from their own national space-borne platforms, providing local rainfall measurements to support the ground validation activities, or providing hardware or launch services for GPM constellation spacecraft. This paper will present an overview of the current planning for the GPM Program, and discuss in more detail the status of the lead author's primary responsibility, development and acquisition of the GPM Microwave Imager.
Flaming, Gilbert Mark↗
Controlling Charging and Arcing on a Solar Powered Auroral Orbiting Spacecraft
The Global Precipitation Measurement satellite (GPM) will be launched into a high inclination (65 degree) orbit to monitor rainfall on a global scale. Satellites in high inclination orbits have been shown to charge to high negative potentials, with the possibility of arcing on the solar arrays, when three conditions are met: a drop in plasma density below approximately 10,000 cm(exp -3), an injection of energetic electrons of energy more that 7-10 keV, and passage through darkness. Since all of these conditions are expected to obtain for some of the GPM orbits, charging calculations were done using first the Space Environment and Effects (SEE) Program Interactive Spacecraft Charging Handbook, and secondly the NASA Air-force Spacecraft Charging Analyzer Program (NASCAP-2k). The object of the calculations was to determine if charging was likely for the GPM configuration and materials, and specifically to see if choosing a particular type of thermal white paint would help minimize charging. A detailed NASCAP-2k geometrical model of the GPM spacecraft was built, with such a large number of nodes that it challenged the capability of NASCAP-2k to do the calculations. The results of the calculations were that for worst-case auroral charging conditions, charging to levels on the order of -120 to -230 volts could occur on GPM during night-time, with differential voltages on the solar arrays that might lead to solar array arcing. In sunlit conditions, charging did not exceed -20 V under any conditions. The night-time results were sensitive to the spacecraft surface materials chosen. For non-conducting white paints, the charging was severe, and could continue unabated throughout the passage of GPM through the auroral zone. Somewhat conductive (dissipative) white paints minimized the night-time charging to levels of -120 V or less, and thus were recommended for GPM thermal control. It is shown that the choice of thermal control paints is important to prevent arcing on high inclination orbiting spacecraft solar arrays as well as for GEO satellites, even for solar array designs chosen to minimize arcing.
Ferguson, Dale C.↗
Reaching for 20 Years with the IMERG Multi-Satellite Products
The latest releases of Global Precipitation Measurement (GPM) mission products cap five years of vigorous development cycle since the launch of the GPM Core Observatory, and these now provide datasets that are relatively homogeneous across the joint Tropical Rainfall Measuring Mission (TRMM) and GPM eras. Version 06 of the U.S. GPM team's Integrated Multi-satellitE Retrievals for GPM (IMERG) merged precipitation product enforces a consistent intercalibration for all precipitation products computed from individual satellites with the TRMM and GPM Core Observatory sensors as the TRMM- and GPM era calibrators, respectively, and incorporates monthly surface gauge data. The basic IMERG algorithm now features precipitation motion vectors (used to drive the Lagrangian interpolation, or "morphing") that arecomputed by tracking vertically integrated vapor fields analyzed in MERRA2 and GEOS5. This innovation provides globally complete coverage, expanding IMERG's coverage beyond the 60°N-S latitude band provided by IR-based vectors, although we continue to mask out precipitation over snowy/icy surfaces as unreliable. A second innovation is the Quality Index (QI) data field. The half-hourly QI is taken as the approximate Kalman Filter correlation computed in the morphing calculation.
Huffman, George J.↗
Climatology of Global Precipitation Measurement Mission Precipitation Regimes and Implications for Global Estimates of Vertical Winds
The Global Precipitation Measurement (GPM) mission Validation Network (VN) framework leverages over 118 ground-based polarimetric Doppler radars to validate a large subset of precipitation measurements and retrievals from the GPM Dual-frequency Precipitation Radar (DPR). Recently, GPM DPR reflectivity profiles within the VN have been classified according to their convective regime using unsupervised machine learning techniques. The archetypal regimes are stratiform, convective, mixed stratiform-convective (e.g., transition regions), and “other” (e.g., peripheral regions of light precipitation). Subcategories within these four primary regimes vary according to the characteristic depth of included reflectivity profiles, resulting in 12 main GPM DPR precipitation profile categories. Polarimetry of ground-based Doppler radars in the VN offers additional insights into the types of precipitation, while pairs of radars positioned near each other enable retrieval of vertical winds via dual-Doppler analysis. Geometrically matched to the DPR reflectivity profiles in the GPM VN, these ground-based data and retrievals contribute more detailed characterization of the distinct kinematic and microphysical structures associated with each of the 12 DPR precipitation regimes. DPR reflectivity profiles linked with wind in the VN are restricted to GPM overpasses of proximal radar pairs that allow dual-Doppler analysis. Although a limited subset of DPR profiles in the VN are matched with vertical motion, agreement between the reflectivity structures paired with wind data and those of the greater DPR dataset in the VN suggest that estimates of vertical motion may be inferred in regions without ground-based measurements. We present a climatology of the 12 convective regimes identified within the DPR VN dataset as well as early efforts to estimate the kinematic and microphysical structures of precipitation profiles within the greater GPM DPR dataset by applying machine learning techniques. Precipitation data paired with global estimates of vertical winds from these efforts offer early insight to and support upcoming missions to retrieve convective mass flux, including the Investigation of Convective Updrafts (INCUS) in the Tropics and the global Atmosphere Observing System (AOS).
Precipitation↗
Conversion of METL Diagnostic Flowmeters to Permanent Magnet Based Electromagnetic Flowmeters
The Mechanisms Engineering Test Loop (METL) uses three flowmeters to monitor sodium circulation through the main loop, the Cold Trap leg, and the Plugging Meter leg. When constructed, the Cold Trap flowmeter (CTFM) and Plugging Meter flowmeter (PMFM) were equipped with permanent magnets and Hall Sensors. By October of 2019, during normal operations, both the CTFM and PMFM failed, producing either erroneous or zero signals. Repairs to the flowmeters were attempted in January of 2020 but failed to resolve the issues. Therefore, starting in March of 2021, a plan was developed to convert the installed flowmeters to more robust permanent magnet based electromagnetic flowmeters (EMFMs). The Cold Trap EMFM (CT EMFM) and Plugging Meter EMFM (PM EMFM) were fully installed by August of 2021. Initial testing and commissioning were completed in November of 2021. Finally, the first calibration runs were finished in March of 2022. This report discusses the design, conversion, and calibration of the as-built CTFM and PMFM to robust permanent magnet based EMFMs. During the design phase, theoretical models were used to estimate the signal output and required magnet sizes. Then, the CTFM and PMFM were disassembled and converted to EMFMs. After commissioning, the CT EMFM and PM EMFM were calibrated using a ‘Time Transfer Procedure’ carried out with METL Expansion Vessels and Test Vessel Two. The accuracy of the calibration was estimated through an uncertainty analysis. Finally, the report describes some lessons learned for future flowmeter conversions and follow-up work. In total, both METL EMFM’s met the desired performance targets. Testing data showed that the METL EMFMs provide a output signal of roughly 2 mV at 1 GPM and 250 °C. During calibration, flowrates between 0.7 GPM and 2.4 GPM were achieved. In this flow range, calibration coefficients of 0.485 and 0.935 were measured as with errors ranging from 15-5% and 16-5% for the CT EMFM and PM EMFM, respectively. Above 1.5 GPM, the error was assumed to be about 5% for both METL EMFMs. Several points will be considered for future follow-up work on the METL EMFM’s. First, the signal noise issues in the PM EMFM will be addressed. It is likely the source of the noise is due to some stray EMF from a heater. Secondly, the NdFeB magnets will be replaced with a grade that has a Curie temperature above 80 °C. For example, a few grades of NeFeB magnets have Curie temperatures which exceed 150 °C and some SmCo magnets have Curie temperatures as high as 500 °C. Third, more calibration runs will be completed in the range of 0.5-2.5 GPM. This will further improve the accuracy of the calibration coefficient. Fourth, calibration runs will be completed up to 5 GPM. This requires a larger pressure relief valve to be installed on the Expansion Vessel and Test Vessel 2, as well as a revised calibration procedure. Lastly, calibration runs will be completed to account for cold spots in the system, which reduced the inlet temperature of the METL EMFMs. Overall, these points will improve the calibration coefficients derived in this work and also improve the performance of the METL EMFMs.
42 ENGINEERING↗
A Process for Producing Highly Wettable Aluminum 6061 Surfaces Compatible with Hydrazine
NASA's Global Precipitation Measurement (GPM) mission is an ongoing Goddard Space Flight Center (GSFC) project whose basic objective is to improve global precipitation measurements. The space-based portion of the mission architecture consists of a primary or core spacecraft and a constellation of NASA and contributed spacecrafts. The efforts described in this paper refer to the core spacecraft (hereafter referred to as simply GPM) which is to be fabricated at GSFC. It has been decided that the GPM spacecraft is to be a "design-for-demise-spacecraft." This requirement resulted in the need for a propellant tank that would also demise or ablate to an appropriate degree upon re-entry. Composite overwrapped aluminum lined propellant tanks with aluminum propellant management devices (PMD) were shown by analyses to demise and thus became the baseline configuration for GPM. As part of the GPM tank development effort, long term compatibility and wettability testing with hydrazine was performed on Al6061 and 2219 coupons fabricated and cleaned by conventional processes. Long term compatibility was confirmed. However, the wettability of the aluminum as measured by contact angle produced higher than desired angles (greater than 30 deg.) with excessive scatter. The availability of PMD materials exhibiting consistently low contact angles aids in the design of simple PMDs. Two efforts performed by Angeles Crest Engineering and funded by GSFC were undertaken to reduce the risk of using aluminum for the GPM PMD. The goal of the first effort was to develop a cleaning or treatment process to produce consistently low contact angles. The goal of the second effort was to prove via testing that the processed aluminum would retain compatibility with hydrazine and retain low contact angle after long term exposure to hydrazine. Both goals were achieved. This paper describes both efforts and the results achieved.
Moore, N. R.↗
NASA’s Global Precipitation Measurement Mission: Leveraging Stakeholder Engagement & Applications Activities to Inform Decision-making
The application of satellite precipitation estimates from NASA’s Global Precipitation Measurement (GPM) Mission for decision-making has been a focus for the mission since launch. As a result, GPM data have enabled a range of applications that address societal needs, including water resource management, crop forecasting, ecological monitoring, disaster response, public health, aviation, weather forecasting, and climate modeling, among others. GPM applications activities have continued to focus on user engagement through in person trainings and interviews, workshops, webinars, and educational outreach activities. The goals of these efforts are to synthesize community data needs in order to effectively support and enable decision-making across agencies, academia and the global community. While these efforts have helped the GPM mission establish a large stakeholder community that encompasses federal and state partners, academic institutions, nd private and nonprofit companies, there remains difficulties associated with accessing, processing, and applying the data to support or enable applications. In this article, we present GPM applications strategies and approaches used to enhance the applications value of GPM data, and most importantly, demonstrate how these efforts have and can inform different decision-making contexts. This work also provides a discussion on key lessons learned from the user community and how this information can be utilized to help better support and shape applications approaches for future NASA Earth Science missions.
Satellite precipitation↗
Managing an Aging Pump-and-Treat Groundwater Remediation System at the Fernald Preserve - 19557
The Fernald Preserve, Ohio, Site underwent restoration and remediation under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). With the exception of the Great Miami Aquifer, the CERCLA remediation was declared physically complete on October 29, 2006, and the site was turned over to the US Department of Energy Office of Legacy Management for long-term care and maintenance. The Record of Decision under CERCLA specifies a concentration-based cleanup that requires the extraction and treatment of Great Miami Aquifer groundwater above Final Remediation Levels (FRLs) until the full, beneficial use potential of the aquifer is achieved, including use as a drinking water source. The area of the aquifer targeted for remediation is 126.5 hectares (312.70 acres). The groundwater pumping remediation was designed by modeling cleanup with the Variable Saturated Analysis Model in 3 Dimensions (VAM-3D) modeling code, developed by Hydrogeologic Inc. The original design called for 23 extraction wells operating at 379 liters per minute (lpm) (100 gallons per minute [gpm]) to 1135 lpm (300 gpm) each for a system total of 18,073 lpm (4775 gpm). In 2014, the system was optimized down to 20 extraction wells operating at 379 to 1893 lpm each for a system total of 19,180 lpm (5075 gpm). To date, pumping has been an effective remediation technology for the aquifer. At the end of 2017, the area of the aquifer remaining above FRLs was down to 38.2 hectares (94.4 acres). From August 1993 through December 2017 (24 years), 6235 kilograms (kg) (13,733 pounds) of uranium were removed from the aquifer by the pumping of 1.74 x 10{sup 11} liters (46.2 billion gallons) of water. Since 2010, treatment of groundwater to achieve regulatory discharge limits at the Great Miami River has not been needed on a routine basis. The ongoing remediation is now essentially a pumping operation, and this water does not require treatment. Metrics reported in the annual Site Environmental Report for the groundwater remediation indicate that, based on the model-predicted estimate of the mass of uranium that needs to be removed from the aquifer to achieve a concentration-based cleanup, the cleanup is approximately 86% - 87% complete. Current model predictions indicate that pumping will need to continue an additional 16 years (until 2035) in some of the wells. During the additional 16 years, it is estimated that approximately 1012 kg (2231 pounds) of uranium will be removed from the aquifer. System pumping rates are designed to decrease over the course of the remaining 16 years, dropping down to a system total of 11,638 lpm (3075 gpm) in 2022 and a system total of 4163 lpm (1100 gpm) in 2033. Even with the designed decreases in pumping rates, it is estimated that approximately 1 x 10{sup 11} liters (26.6 billion gallons) of water will be pumped from the aquifer to remove 1012 kg (2231 pounds) of uranium. This indicates that the remaining 16 years of operation will be much less efficient than the first 24 years. Decreasing efficiency is common for pumping operations. The worst-case scenario is that decreasing concentration trends stabilize above the cleanup FRLs and remediation goals are never achieved. Performance assessments of the pumping remedy will need to be routinely conducted to determine if pumping should be discontinued, if it should be continued but optimized, or if the pumping technology can be supplemented with a different technology that will improve the outcome of the remediation and make the operation more efficient and successful. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Advanced magnetic suspensions for vibration isolation and fast-attitude control of space-based generic pointing mounts
Advanced magnetic suspension for vibration isolation and fast-attitude control of space-based generic pointing mounts (GPM) is presented in the form of viewgraphs. The following subject areas are covered: design criteria for GPM; GPM system features; GPM performance characteristics; GPM functional block diagram; and other applications for generic magnetic suspension technologies.
Bosley, Robert W.↗
The Global Precipitation Mission
The Global Precipitation Mission (GPM), expected to begin around 2006, is a follow-up to the Tropical Rainfall Measuring Mission (TRMM). Unlike TRMM, which primarily samples the tropics, GPM will sample both the tropics and mid-latitudes. The primary, or core, satellite will be a single, enhanced TRMM satellite that can quantify the 3-D spatial distributions of precipitation and its associated latent heat release. The core satellite will be complemented by a constellation of very small and inexpensive drones with passive microwave instruments that will sample the rainfall with sufficient frequency to be not only of climate interest, but also have local, short-term impacts by providing global rainfall coverage at approx. 3 h intervals. The data is expected to have substantial impact upon quantitative precipitation estimation/forecasting and data assimilation into global and mesoscale numerical models. Based upon previous studies of rainfall data assimilation, GPM is expected to lead to significant improvements in forecasts of extratropical and tropical cyclones. For example, GPM rainfall data can provide improved initialization of frontal systems over the Pacific and Atlantic Oceans. The purpose of this talk is to provide information about GPM to the USWRP (U.S. Weather Research Program) community and to discuss impacts on quantitative precipitation estimation/forecasting and data assimilation.
Braun, Scott↗