Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “EXPORTS”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Building a Bilingual Google Earth Engine Dashboard to Increase Accessibility to Long-term Time Series Remote Sensing Data for Monitoring Saline System Changes in Chile’s Atacama Desert

Saline systems, consisting of salt flats, ponds, and marshes, provide vital water resources to wildlife and communities in northern Chile’s Atacama Desert, one of the driest regions in the world. Mining is extensive in the Atacama, which contains 30% of the world’s lithium reserves and is abundant in potassium and boron. The groundwater that feeds into salt marshes and ponds is extracted in large volumes for mining operations, limiting the availability of water for ecosystems. However, identifying long-term and large-scale environmental impacts from local lithium mining on the saline systems is limited by region inaccessibility and terrain variability. Open access satellite imagery and cloud computing technology has made studying Atacama saline systems feasible and allowed for collaboration across different agencies and countries. The NASA DEVELOP Program partnered with Chile’s la Universidad de La Serena and Servicio Nacional de Geología y Minería (SERNAGEOMIN) to create the Saline Analysis Tool (SalT) in Google Earth Engine (GEE). SalT is used to analyze the extent and distribution of remote saline systems in the Atacama from 1986 to the present day. The tool filters Landsat 5 Thematic Mapper (TM) and Landsat 8 Operational Land Imager (OLI) data from GEE’s data catalog and creates a single composite image per year for analysis. Additional output analyses include land cover classification, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) raster images that can be displayed on the map interface or exported. The tool can also generate time-lapse videos and charts displaying NDVI, NDWI, and land cover over time. A key feature of the tool is the use of a bilingual graphical user interface to make analysis accessible and customizable to different users’ needs—SalT provides options to select an analysis area, analysis time period, and outputs to display or export. The tool also incorporates new Earth observations as they are added to GEE’s catalog. The ability to easily visualize and analyze long-term remote sensing imagery will enable SERNAGEOMIN and la Universidad de la Serena to continually monitor changes in these saline systems and inform future land management policy.

NASA DEVELOP↗
NASA NTRS2017

Characterization Testing of Lockheed Martin High-Power Micro Pulse Tube Cryocooler

This paper describes the thermal vacuum, microphonics, magnetics, and radiation testing and results of a Lockheed Martin high-power micro pulse tube cryocooler. The thermal performance of the microcooler was measured in vacuum for heat reject temperatures between 185 and 300 K. The cooler was driven with a Chroma 61602 AC power source for input powers ranging from 10 to 60 W and drive frequency between 115 and 140 Hz during thermal performance testing. The optimal drive frequency was dependent on both input power and heat reject temperature. In addition, the microphonics of the cooler were measured with the cooler driven by Iris Technologies LCCE-2 and HP-LCCE drive electronics for input powers ranging from 10 to 60 W and drive frequency between 135 and 145 Hz. The exported forces were strongly dependent on input power while only weakly dependent on the drive frequency. Moreover, the exported force in the compressor axis was minimized by closed loop control with the HP-LCCE. The cooler also survived a 500 krad radiation dose while being continuously operated with 30 W of input power at 220 K heat rejection temperature in vacuum. Finally, the DC and AC magnetic fields around the cooler were measured at various locations.

Rodriguez, Jose I.↗
NASA NTRS2018

Characterization Testing of Lockheed Martin Micro1-2 Cryocoolers Optimized for 220 K Environment

The Mapping Imaging Spectrometer for Europa (MISE) Instrument on the Europa Clipper mission has baselined a Lockheed Martin high-power Micro1-2 pulse tube cryocooler operating at 135 Hz with a 220 K heat rejection temperature. This paper describes the testing and results of two Lockheed Martin Micro1-2 coolers optimized for these conditions. The thermal performance of the microcoolers was measured in vacuum for heat reject temperatures between 220 and 230 K. The coolers were operated with input powers ranging from 5 W to 40 W and drive frequency between 125 Hz and 145 Hz. The optimal drive frequency was strongly dependent on heat reject temperature. In addition, the exported forces and torques of the coolers were measured at 300 K heat rejection for input powers ranging from 5 W to 60 W and drive frequency between 120 Hz and 160 Hz. The exported forces were dependent on both piston amplitude and drive frequency. Moreover, the following were measured on one of the coolers: DC and AC magnetic fields at various locations, the off-state conductance of the pulse tube, and the effect of inclination angle of the pulse tube relative to gravity on the performance of the cooler. Finally, one of the coolers was subjected to random vibration testing.

Rodriguez, J.I.↗
DOE OSTI2015

Valuation-Based Framework for Considering Distributed Generation Photovoltaic Tariff Design: Preprint

While an export tariff is only one element of a larger regulatory framework for distributed generation, we choose to focus on tariff design because of the significant impact this program design component has on the various flows of value among power sector stakeholders. In that context, this paper is organized into a series of steps that can be taken during the design of a DGPV export tariff design. To that end this paper outlines a holistic, high-level approach to the complex undertaking of DGPV tariff design, the crux of which is an iterative cost-benefit analysis process. We propose a multi-step progression that aims to promote transparent, focused, and informed dialogue on CBA study methodologies and assumptions. When studies are completed, the long-run marginal avoided cost of the DGPV program should be compared against the costs imposed on utilities and non-participating customers, recognizing that these can be defined differently depending on program objectives. The results of this comparison can then be weighed against other program objectives to formulate tariff options. Potential changes to tariff structures can be iteratively fed back into established analytical tools to inform further discussions.

14 SOLAR ENERGY↗
DOE OSTI2014

PNNL Strategic Goods Testbed: A Data Library for Illicit Nuclear Trafficking

Pacific Northwest National Laboratory (PNNL) has put significant effort into nonproliferation activities as an institution, both in terms of the classical nuclear material focused approach and in the examination of other strategic goods necessary to implement a nuclear program. To assist in these efforts, several projects in the Analysis in Motion (AIM) and Signature Discovery (SDI) Initiatives at PNNL are developing machine learning methodology for human-computer interaction in real time environments to assist analysts in this domain. All of these technical projects require access to data – whether it is in terms of detector data, shipping records, financial information, company relations, or other communications. The first question that mathematical and computational researchers come up with when asked to build analyst assist or automated tools is “What does the data look like? ” They become frustrated when basic questions like this can not be easily answered and this can have the effect of pushing researchers away from the nuclear trafficking domain, especially in strategic commodity and export control areas where data sets can not easily be generated through standard experimental techniques. For small projects that are building a proof of concept for their methodology, obtaining this data can be arduous and expensive. To relieve the burden of data collection from these projects and grow a lab-wide capability, the Strategic Goods Testbed Team has taken over data collection and placed subscriptions and access to flat data files in a centralized location so that all projects can benefit from these items. We have collected shipping data in the form of PIERS records, judicial information about export control cases, NAC data on the nuclear fuel industry, and financial data from Dun and Bradstreet and our data sets are continuing to expand. With a single access agreement, researchers in data-mining and other fields can utilize all of the records that have been downloaded, make requests through subscription services, and interact with other researchers through our interface. Our testbed team provides more than a simply static repository by working with researchers to refine their data needs and insure data quality as well as quantity. We are currently working with laboratory and initiative specific management to examine effective ways for continuing data growth and sustainability.

data capability↗
DOE OSTI2012

Pan Genome of the Phytoplankton Emiliania Underpins its Global Distribution

Coccolithophores have influenced the global climate for over 200 million years1. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems2. They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering themvisible fromspace3.Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO 2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO 2 production or uptake, sequestration and export to the deep ocean4. Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate thatE. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

SimulatorToFMU v0.1

SimulatorToFMU is a software package written in Python which allows users to export a memoryless Python-driven simulation program or script as a Functional Mock-up Unit (FMU) for model exchange or co-simulation.In CyDER (Cyber Physical Co-simulation Platform for Distributed Energy Resources in Smart Grids), SimulatorToFMU will allow exporting OPAL-RT as an FMU. This will enable OPAL-RT to be linked to CYMDIST and GridDyn FMUs through a standardized open source interface.

Nouidui, Thierry↗
DOE OSTI2020

GIS Visualization of Transportation Energy Consumption

Transportation is witnessing unprecedented transformation, where emerging technologies are disrupting the way we travel. Be it sharing economy, or micro-mobility, the landscape of urban transportation is undergoing a much-needed paradigm shift. In order to capture and model these shifts, researchers need to be agile in their studies of the current and future transportation landscape. The need for agility in turn calls for sophisticated, intuitive, and reliable means to visualize and share transportation data. Travel is inherently spatial, so methods of visualizing transportation information should also be rooted in spatial analysis. Geographic Information Systems (GIS) are the premier technological framework to analyze and display spatial data. GIS tools have been used in the past to depict flow of vehicles, and display of network conditions (speed, congestion, etc.). However, in an ever-changing technological landscape, spanning advancements in vehicle as well as information systems, depicting vehicle flows falls short of providing a comprehensive picture of the impact these advancements have on travel related energy consumption. To address this issue, this research effort presents a web-based mapping application to visualize how travel related energy flows across a city. The application is being developed by National Renewable Energy Laboratory researchers to integrate various transportation energy consumption models within a GIS schema. This has the goal of enabling rapid analysis of energy impacts of the dramatically evolving transportation environment. The application is being developed using a Python framework for ArcGIS Online. Using road network data from the City of Columbus, Ohio and traffic data from CATT Laboratory's Regional Integrated Transportation Information System, transportation energy consumption will be modeled at a macro level. The application aims to provide highly accurate data while still maintaining the flexibility needed to adapt the model when new technologies arise. The methodology presented through this effort is expected to provide insights into how light-duty vehicles use energy on a large scale based on the road network they use. The application will also provide data exports to enable sharing and collaboration. " need for agility in turn calls for sophisticated, intuitive, and reliable means to visualize and share transportation data. Travel is inherently spatial, so methods of visualizing transportation information should also be rooted in spatial analysis. Geographic Information Systems (GIS) are the premier technological framework to analyze and display spatial data. GIS tools have been used in the past to depict flow of vehicles, and display of network conditions (speed, congestion, etc.). However, in an ever-changing technological landscape, spanning advancements in vehicle as well as information systems, depicting vehicle flows falls short of providing a comprehensive picture of the impact these advancements have on travel related energy consumption. To address this issue, this research effort presents a web-based mapping application to visualize how travel related energy flows across a city. The application is being developed by National Renewable Energy Laboratory researchers to integrate various transportation energy consumption models within a GIS schema. This has the goal of enabling rapid analysis of energy impacts of the dramatically evolving transportation environment. The application is being developed using a Python framework for ArcGIS Online. Using road network data from the City of Columbus, Ohio and traffic data from CATT Laboratory's Regional Integrated Transportation Information System, transportation energy consumption will be modeled at a macro level. The application aims to provide highly accurate data while still maintaining the flexibility needed to adapt the model when new technologies arise. The methodology presented through this effort is expected to provide insights into how light-duty vehicles use energy on a large scale based on the road network they use. The application will also provide data exports to enable sharing and collaboration.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2022

OpenPATH and Itinerum Integration: A Case Study of Merging Open-Source Projects: Preprint

Throughout the transportation sector, multiple mobility tracking platforms have been developed independently, in parallel, with similar use cases and infrastructure. Maintaining such platforms on an individual level can result in duplicated effort. Innovation within the field could be slowed by the limited resource of people working on extremely similar projects. We provide a case study in how such platforms can be combined with low effort and provide an example in the mobility domain of what the resulting integration points, modules and ownership may look like. OpenPATH (formerly e-mission) and Itinerum are two examples of similar independently developed human mobility tracking platforms that extend beyond standard traffic data collection. Due to the open source nature of the projects, members from both teams decided to merge the functionality, thereby only hosting a single data collection process and limiting maintenance of separate intake platforms. On the front-end, specific questionnaire functionality from Itinerum, mainly the ability to display and return questions and results focused on sociodemographic attributes, was integrated into the OpenPATH user interface. On the back-end, an export pipeline stage was created to transport collected data back to the Itinerum database. Upon completion, the OpenPATH application retained its original functionality while adding the ability to export data for future data sharing and creating an avenue to incorporate Itinerum hosted questions and answers. Itinerum benefits from the rich feature set and infrastructure of OpenPATH without losing needed elements such as the questionnaire component. This case study, within the transportation sector, illustrates the various configurations in which open source software can be developed, maintained and deployed.

ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2012

OSRP Source Repatriations-Case Studies: Brazil, Ecuador, Uruguay

The Global Threat Reduction Initiative's (GTRI) Offsite Source Recovery Project (OSRP) began recovering excess and unwanted radioactive sealed sources (sources) in 1999. As of February 2012, the project had recovered over 30,000 sources totaling over 820,000 Ci. OSRP grew out of early efforts at Los Alamos National Laboratory (LANL) to recover disused excess Plutonium- 239 (Pu-239) sources that were distributed in the 1960's and 1970's under the Atoms for Peace Program. Source recovery was initially considered a waste management activity. However, after the 9/11 terrorist attacks, the interagency community began to recognize that excess and unwanted radioactive sealed sources pose a national security threat, particularly those that lack a disposition path. After OSRP's transfer to the U.S. National Nuclear Security Administration (NNSA) to be part of GTRI, its mission was expanded to include all disused sealed sources that might require national security consideration. Recognizing the transnational threat posed by porous borders and the ubiquitous nature of sources, GTRI/OSRP repatriates U.S. origin sources based on threat reduction prioritization criteria. For example, several recent challenging source repatriation missions have been conducted by GTRI/OSRP in South America. These include the repatriation of a significant amount of Cs-137 and other isotopes from Brazil; re-packaging of conditioned Ra-226 sources in Ecuador for future repatriation; and, multilateral cooperation in the consolidation and export of Canadian, US, and Indian Co-60/Cs-137 sources from Uruguay. In addition, cooperation with regulators and private source owners in other countries presents opportunities for GTRI/OSRP to exchange best practices for managing disused sources. These positive experiences often result in long-term cooperation and information sharing with key foreign counterparts. International source recovery operations are essential to the preservation of U.S. national security interests. They are also mutually beneficial for fostering positive relationships with other governments and private industry, and demonstrate that responsible end-of-life options are given to legacy U.S.-origin sources in other countries. GTRI/OSRP does not take back sources that have a viable path for commercial disposal. Most US origin sources were sold commercially and were not provided by the US government. Below is a synopsis of cooperative efforts with Brazil, Ecuador, and Uruguay. Bilateral and multilateral efforts have been successful in removing hundreds of U.S.origin sealed radioactive sources from Latin American countries to the U.S. As many disused sources remain in the region, and since repatriation is not always an option, GTRI will continue to work with those countries to ensure that these sources are stored securely for the long-term. Successful Latin America operations should serve as a model for other regional cooperation in the repatriation of sealed sources, encouraging other source exporting countries to implement similar programs. Securing and removing sources, both domestically and internationally, is crucial to strengthening the life-cycle management of radioactive sources worldwide. Such efforts not only prevent these materials from being used maliciously, but also address public health and safety concerns, and under-gird the IAEA Code of Conduct on the Safety and Security of Radioactive Sources. (authors)

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2016

Remote Retrieval, Disruption and Processing of Legacy Nuclear Waste - 16179

The UK National Nuclear Laboratory (NNL) is currently undertaking, in conjunction with Sellafield Ltd, a series of high profile trials of robotic equipment on a full scale test facility at their Workington Laboratory in England. These trials are designed to underpin and substantiate the processes proposed for the remote retrieval, disruption and processing of legacy Miscellaneous Beta Gamma Waste (MBGW) from a number of different donor plants on the Sellafield site, including some of the older fuel storage ponds and storage silos. These processes will be conducted inside the new Box Encapsulation Plant (BEP) which is due to be commissioned at Sellafield by 2020. These processes will subsequently enable Sellafield Ltd to safely recover legacy Intermediate Level Waste (ILW) from the older storage facilities on site and process it into a safer form which is more suitable for long term storage and then ultimately final disposal in a Geological Disposal Facility. As part of this legacy waste processing within the BEP plant, MBGW waste items will have to be remotely removed from a variety of different types of import skips. This waste will then be transferred, using robots, into the export container, which is a 3 m{sup 3} box liner, where the processed waste will be flood grouted to produce an encapsulated waste package. As part of this processing, any MBGW items consisting of sealed containers will have to be remotely disrupted before being grout encapsulated. This disruption is in order to (a) release any trapped liquors or gases from the containers and (b) ensure full grout infiltration of the container contents, thus minimising the amount of free liquors and voids within the final waste product. The NNL are conducting this technical work to confirm the viability of the proposed concept, processes and equipment. The developed solution consists of a linear layout of processing equipment with a pair of heavy duty, standard industrial, 'commercially off the shelf' (COTS) robots positioned around a Waste Handling Table. These robots have a 500 kg payload capacity and are operated remotely to handle all of the various types of MBGW waste, including the heavy and bulky items. The robots can be operated in manual tele-operation mode as well as pre-programmed automatic mode and have a range of primary and secondary tooling in order to perform the waste processing and disruption tasks as well as undertake general house-keeping and cleaning duties within the cell. The main tools include two types of hydraulic grab for the main waste recovery and handling tasks and a hydraulic shear for the waste disruption activities, but a number of other tools have also been designed and built for ancillary activities, such as a set of general purpose gripper jaws, drilling tool, bolt removal tool, pump tool, spray tool and a number of different housekeeping tools etc. The robot trials were started in November 2014, and have attracted a significant degree of high level stakeholder interest, including the UK Nuclear Decommissioning Authority (NDA), Office for Nuclear Regulation (ONR), Environment Agency (EA) and Radioactive Waste Management Limited (RWML) witnessing a number of the critical demonstration trials. Robots of the type selected are readily available, robust, reliable and easy to use. The trials have been very successful in proving the retrieval, processing and disruption operations, reducing the burden in the legacy waste facilities. Utilising robots to perform these tasks will lower the probability of producing non-compliant waste packages. In addition the robots can increase the consolidation of incoming waste skips into outgoing 3 m{sup 3} box liners, significantly increasing packing efficiencies and reducing the overall number of export containers produced thus lowering the decommissioning and waste storage/disposal costs. The trials have also enabled an assessment of the optimum way to operate the robots, as well as their reliability and maintainability issues. Engineering work associated with recovering failed robots and removing them from a typical Sellafield plant environment and then subsequently replacing them with functioning robots has also been undertaken and further work is now planned. The success of the trials, completed safely to a very challenging timescale, has enabled the use of robots in BEP to be endorsed as a viable option by the key stakeholders. Following a robust decision making process, this was a clear cut decision. The technical development and testing of the robot technology is currently continuing in order to investigate areas such as robot reliability, failure recoveries, human factors, ease of waste identification, optimisation of throughput rates, nuclearisation modifications etc. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Climatic Controls on Residual Contaminants Under Sustainable Remediation - 18699

We investigate the impact of climate change on residual contaminants in soil and groundwater under sustainable remediation. We illustrate seven climate change scenarios which mimic shifts in the precipitation regime as well as the failure of the source-zone cap. We evaluate different performance metrics including contaminant concentrations at multiple wells and export to a creek. The approach is demonstrated by simulating the tritium plume migration at the Savannah River Site F-Area, USA. The cap integrity is critical not only to reduce the well concentrations and export but also to reduce the uncertainty associated with the climatic variability. Sampling or in situ monitoring near the source zone is important for the early detection of plume mobility changes. Realistic hydrological models are necessary to evaluate the trade-offs (mobility vs dilution)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Hydrological Controls on Residual Contaminants Under Sustainable Remediation - 19287

This paper investigates the impact of natural aquifer's recharge shifts induced by precipitation changes on residual contaminants located in soil and groundwater, subject to sustainable remediation techniques. We illustrate five climate change scenarios which mimic shifts in the natural recharge regime. We evaluate the impact on different performance metrics that include contaminant concentrations at observation wells and contaminant export to a creek. The approach is demonstrated by simulating the tritium plume migration within a U.S. Department of Energy's nuclear reservations: the Savannah River Site F-Area. Results show that increasing the aquifers' recharge initially causes a decrease in the well concentrations due to dilution, and subsequently an increase due to the mobilization of contaminants from the vadose zone. As the recharge shift increases, the peak concentration is higher and may occur at an earlier stage. The mobilized contaminants reach the wells or control planes several years or decades later than the precipitation events thus monitoring near the source zone is important for early detecting mobilized contaminants. Moreover, we observe that, even when the well concentrations are significantly affected, the export at the control planes may not be affected by shifts in the natural recharge regime therefore the risk of downgradient population may be under control even under significant hydrological changes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Towards Vendor and Operating System Independence of USB-based portable multi-channel analyzers

The nuclear measurements group is called on to develop portable, user friendly systems that performs at, or near, laboratory standards. These systems typically consist of a detector and a USB-based multi-channel analyzer. An ORTEC digi-Base is an example of a USB-based portable multi-channel analyzer with 14-pin photomultiplier tube base for gamma-ray spectroscopy applications with NaI(Tl) and other scintillation detectors. Operating system independence - we want to be able to develop applications that are 'future-proof' and can run on the best hardware for the job: desktop, laptop, tablet, phone, or embedded device. To do that we need our software to be operating system independent. Hardware vendor independence - to use the most appropriate equipment for the job, while still maintaining our rapid method development, we would like our software that uses this equipment to be independent of the specific vendor or model of the hardware. To do that we need a common interface to each vendor's equipment (high voltage, gain, start, stop, clear, etc.) In prior work, we were able to use an existing library to communicate with an ORTEC digi-base via Linux and Android. However the application developed did not have a user friendly front-end. Part of this work was to develop a simple user interface to control the settings of the hardware from Android. While OS independence is the final goal, another goal is standardized software for user-application development. For current purposes those standard systems are Windows 7, Windows 10, and Python 3. Our next step was to develop a common software interface between a front-end user interface and back-end hardware communication software. This was done using Python's Ctypes library. Ctypes is a foreign function library for Python. It provides C compatible data types, and allows calling functions in DLLs or shared libraries. It can be used to wrap these libraries in pure Python. Ctypes exports the cdll, and Windows windll and oledll objects, for loading dynamic link libraries. You load libraries by accessing them as attributes of these objects. cdll loads libraries which export functions using the standard cdecl calling convention. The first steps of developing the common software interface have been done. Once the software interface has been developed the next goal will be to develop hardware specific back-end software that way rapid user facing software can be developed using equipment that is 'on-hand' and once finished prototyping, the 'best' hardware can be chosen for the specific implementation.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Optimization design of helium circulator diffuser in HTR-PM - 18488

Circulator is very important in HTR-PM. It needs to supply enough pressure rise to circulate cooled helium in the primary loop of HTR-PM to bring heat out. Its pressure rise requirement is the highest among the worldwide circulators. Diffuser is one main component to produce pressure rise for circulator. And the most particular for HTR-PM is that the helium must flow out from two round tubes after flowing through the diffuser, which is very different from other circulators. This special export structure increases flow loss and decreases diffuser efficiency. So it is necessary to optimize diffuser to satisfy high pressure rise requirement of HTR-PM circulator with the special export structure. Four geometrical variables of diffuser have been studied and optimized. Based on the flow and performance analysis, the optimum structure was chosen. Then the detailed simulation was done by combining it with impeller to obtain performance characteristics of the whole circulator. Finally, the simulation results were compared with experimental results. It was obtained that simulation pressure rise was 201 kPa and experimental result was 210 kPa, which verified that optimization design of diffuser was effective. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

GPU Acceleration of Kernel Density Estimators in Monte Carlo Neutron Transport Simulations

Kernel Density Estimators (KDEs) have recently been explored for use in Monte Carlo radiation transport simulations as an alternative to histogram tallies for capturing spatially-resolved quantities such as neutron flux and reaction rates. Histogram tallies suffer from large uncertainties when detailed spatial resolution of the quantity of interest is required; increasing the resolution of the underlying mesh increases the uncertainty in each histogram bin. KDEs obtain estimates of underlying densities on user-defined points, with the uncertainty at those points being independent of the spatial resolution desired since collisions and particle-track segments are allowed to contribute to the score at multiple tally points. Thus, KDEs show potential for obtaining estimates of a smoother spatially-resolved with reduced variance when compared to a histogram. However, this ability that enables KDEs to obtain lower uncertainties per particle history is more computationally expensive than using a traditional histogram bins on a structured mesh. While KDEs are capable of producing lower tally uncertainties compared to histogram binning for a given number of histories, their increased computational cost may make them less efficient. Even so, it is possible to reduce this additional cost by exporting the KDE tally routines onto Graphics Processing Units (GPUs). GPUs are commonly found on high-performance computing machines as a means of increasing performance without adding additional compute nodes. While it is difficult for existing Monte Carlo radiation transport codes to take advantage of GPUs without rewriting large portions of the code, it is possible to leverage GPUs through heterogeneous computing. This work uses a modified version of OpenMC and exports the KDE tally routines onto a GPU to obtain problem-dependent speedups ranging between 1.6 and 5.0 for the problem studied in this paper. While this methodology is applied to KDEs, the same ideas can be applied to other computationally expensive vectorizable portions of Monte Carlo algorithms. (authors)

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2017

Open Source Release of NJOY2016 and NJOY21

NJOY has been the standard for nuclear data processing for many decades. NJOY is a comprehensive computer code used to produce point-wise and multigroup nuclear data application libraries from cross sections and related quantities obtained from evaluated nuclear data in the Evaluated Nuclear Data Format (ENDF). NJOY was first publicly released in 1977 and distributed by what is now the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory and the National Energy Software Center (NESC) at Argonne National Laboratory. From that time until the release of NJOY2012, NJOY has been distributed by RSICC and made available to researchers outside the United States by agreements between RSICC and the NEA Databank. NJOY2012 was distributed by the Feynman Center at Los Alamos National Laboratory which did not have agreements with the NEA Databank, thus making it more difficult for non US citizens to obtain copies of NJOY2012. Furthermore, NJOY has had export control restrictions preventing some researchers from obtaining NJOY at all. Two new versions of NJOY have been released, NJOY2016 and NJOY21, in January of 2017. Both NJOY2016 and NJOY21 have been released with no export control restrictions and are distributed with an open-source license. This is a big departure from previous releases and impacts not only who has access to NJOY, but also how updates are made available to users and how collaboration is facilitated among interested developers. In addition to distributing NJOY2016 and NJOY21 with an open-source license, these two new versions provide new capabilities for NJOY which will maintain NJOY as the standard for nuclear data processing into the foreseeable future. We report in this summary about the changes that come with these two new versions of NJOY and how this impacts the users and long-time contributors to NJOY.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Improving and Automating Building Model Data Exchange

There are many instances throughout a project’s lifecycle where there arises a need for quick and accurate risk assessment of building designs. For example, an unexpected design change during construction may necessitate structural engineers to perform a seismic risk assessment on analytical models of the updated building design using high fidelity structural analysis software, such as ANSYS or Abaqus. However, the efficiency of such workflows often depends upon the interoperability of architectural design software and structural analysis software. When the quality of this interoperability is lacking or even non-existent, the efficiency of virtual engineering workflows is hampered, which increases project costs. A McGraw Hill industry survey of professional users of Building Information Modeling (BIM) technologies found that there is high demand for BIM interoperability for structural analysis, but that the value/difficulty ratio is currently too low for practical use. There have been efforts by the academic community to facilitate model data exchange between the architectural design and structural analysis domains, but such solutions have not been widely adopted by industry, face technical challenges, and oftentimes are limited in applicability for users of various BIM software. Therefore, INL is developing capabilities to improve, automate, and generalize model data exchange between architectural BIM software (e.g., Revit) and structural analysis software (e.g., SAP2000, ANSYS). The goal is to help expedite and automate as much of the pre-processing step for creating analytical models in finite element analysis software as reasonably as possible. Such a "BIM-to-FEA" conversion tool should provide direct benefit to end-users through accuracy, automation, quick turn-around, and wide applicability. To generalize the application of this BIM-to-FEA conversion tool and increase its useability among the many different commercial BIM software currently used by industry, the program is being developed with the concept of openBIM. OpenBIM is the application of non-proprietary, open data standards that allow for BIM model data exchange in a format that is accessible, retainable, and useable for all users. The most widely used open, non-proprietary data exchange format for BIM is the Industry Foundation Classes (IFC) schema. IFC is developed by buildingSMART international and is ISO certified (ISO 16739-1:2018). The BIM-to-FEA conversion tool is being developed for compatibility with typical commercial building designs of steel framed structures. The tool is currently capable of importing architectural BIM data of framed building structures, recognizing and extracting the aspects of the model that are required for structural analysis, adjusting the connectivity of frame members, and finally exporting to an analytical model stored in the IFC format. The exported IFC analytical model can then be imported into various openBIM compliant software, such as SAP2000. Such capabilities have already been tested on commercial software, as shown above, and continue to be improved. Work is underway to test the conversion on various commercial BIM software, develop a user-friendly interface, incorporate the program into the broader DeepLynx data warehouse project being developed by INL, and to eventually open-source the tool for the benefit of the community. Future development of the tool envisions the ability for efficient iterative risk assessment of generative building designs, all within a workflow utilizing open-source tools. One such open-source tool will be MOOSE, an advanced finite element analysis tool developed at INL. The conversion tool will also branch out from typical commercial building designs and will aim to incorporate nuclear construction. The aim will be to convert both structural and non-structural components of nuclear facilities, such as curved concrete containment structures and piping systems, respectively.

97 MATHEMATICS AND COMPUTING↗