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Design Construction and Operation of a Supercritical Carbon Dioxide (sCO2) Loop for Investigation of Dry Cooling and Natural Circulation Potential for Use in Advanced Small Modular Reactors Utilizing sCO2 Power Conversion Cycles

Middleton, Bobby D.; Rodriguez, Salvador B.; Carlson, Matthew

The second-generation particle size velocity (Parsivel2, Figure 1) disdrometer, or laser disdrometer, referred to as “LDIS” within the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) User Facility, is a modern, laser-based disdrometer designed for comprehensive and reliable measurement of all types of precipitation. LDIS captures detailed information on the size and velocity of individual hydrometeors that fall to the ground, classifying them into a range of 32 categories. These raw measurements are processed by a fast signal processor (provided by the vendor) to calculate various parameters, including precipitation type, amount, intensity, kinetic energy, visibility in the precipitation, and equivalent radar reflectivity. These measurements have served as the primary data set and a valuable reference for a variety of studies, ranging from observational analyses of precipitation processes and climate model evaluations to monitoring or validating radar/satellite retrievals (e.g., Wang et al. 2018, Giangrande et al. 2019, Jackson et al. 2020).

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TYPE SAND Report YEAR 2015
DOIOSTI

Alternatives to the 15% Rule

Broderick, Robert J.; Rylander, Matthew; Reno, Matthew J.; Munoz-Ramos, Karina; Quiroz, Jimmy E.; Smith, Jeff; Rogers, Lindsey; Dugan, Roger; Mather, Barry; Coddington, Michael; Gotseff, Peter; Ding, Fei

The third solicitation of the California Solar Initiative (CSI) Research, Development, Demonstration and Deployment (RD&D) Program established by the California Public Utility Commission (CPUC) is supporting the Electric Power Research Institute (EPRI), National Renewable Energy Laboratory (NREL), and Sandia National Laboratories (SNL) with collaboration from Pacific Gas and Electric (PG&E), Southern California Edison (SCE), and San Diego Gas and Electric (SDG&E), in research to improve the Utility Application Review and Approval process for interconnecting distributed energy resources to the distribution system. Currently this process is the most time - consuming of any step on the path to generating power on the distribution system. This CSI RD&D solicitation three project has completed the tasks of collecting data from the three utilities, clustering feeder characteristic data to attain representative feeders, detailed modeling of 16 representative feeders, analysis of PV impacts to those feeders, refinement of current screening processes, and validation of those suggested refinements. In this report each task is summarized to produce a final summary of all components of the overall project.

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TYPE SAND Report YEAR 2015
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Authentication Without Secrets

Pierson, Lyndon G.; Robertson, Perry J.

This work examines a new approach to authentication, which is the most fundamental security primitive that underpins all cyber security protections. Current Internet authentication techniques require the protection of one or more secret keys along with the integrity protection of the algorithms/computations designed to prove possession of the secret without actually revealing it. Protecting a secret requires physical barriers or encryption with yet another secret key. The reason to strive for "Authentication without Secret Keys" is that protecting secrets (even small ones only kept in a small corner of a component or device) is much harder than protecting the integrity of information that is not secret. Promising methods are examined for authentication of components, data, programs, network transactions, and/or individuals. The successful development of authentication without secret keys will enable far more tractable system security engineering for high exposure, high consequence systems by eliminating the need for brittle protection mechanisms to protect secret keys (such as are now protected in smart cards, etc.). This paper is a re-release of SAND2009-7032 with new figures numerous edits.

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TYPE SAND Report YEAR 2015
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EMR Coupling into Systems: Calibration of the Sandia Reverberation Chamber and Validation of the Single Slot Aperture Gain Model

Jursich, Mark

Electromagnetic threats to weapon systems are always specified in terms of an incident plane wave. Sandia strongly prefers to test electromagnetic susceptibility in a reverberation chamber because a reverberant environment does not allow any potential point of entry to be shadowed. At the same time, a reverberation chamber averages out the directive gain of any points of entry. This would result in an under test of the system. Subsequently, a plane wave correction factor is needed to relate the plane wave and reverberation environments. Warne, et al, at Sandia have developed a theoretical correction factor and a previous attempt to validate it using an anechoic chamber (Higgins & Charley, Electromagnetic Radiation (EMR) Coupling into Complex Systems Aperture Coupling into Canonical Cavities in Reverberant and Anechoic Environments and Model Validation (SAND2007-7391), 2007) was not conclusive. In this current work the theoretical factor has been validated by creating the plane wave environment inside a gigahertz transverse electromagnetic (GTEM) cell instead of an anechoic chamber. The correlation is excellent at all but the lowest frequencies tested. The discrepancy in the low frequency regime is understood in terms of limits on the test capabilities.

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TYPE SAND Report YEAR 2015
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Thermal-Hydrology Simulations of Disposal of High-Level Radioactive Waste in a Single Deep Borehole

Hadgu, Teklu; Stein, Emily; Hardin, Ernest; Freeze, Geoffrey; Hammond, Glenn E.

Simulations of thermal-hydrology were carried out for the emplacement of spent nuclear fuel canisters and cesium and strontium capsules using the PFLOTRAN simulator. For the cesium and strontium capsules the analysis looked at disposal options such as different disposal configurations and surface aging of waste to reduce thermal effects. The simulations studied temperature and fluid flux in the vicinity of the borehole. Simulation results include temperature and vertical flux profiles around the borehole at selected depths. Of particular importance are peak temperature increases, and fluxes at the top of the disposal zone. Simulations of cesium and strontium capsule disposal predict that surface aging and/or emplacement of the waste at the top of the disposal zone reduces thermal effects and vertical fluid fluxes. Smaller waste canisters emplaced over a longer disposal zone create the smallest thermal effect and vertical fluid fluxes no matter the age of the waste or depth of emplacement.

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TYPE SAND Report YEAR 2015
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High Fidelity Simulations of Large-Scale Wireless Networks

Onunkwo, Uzoma

The worldwide proliferation of wireless connected devices continues to accelerate. There are 10s of billions of wireless links across the planet with an additional explosion of new wireless usage anticipated as the Internet of Things develops. Wireless technologies do not only provide convenience for mobile applications, but are also extremely cost-effective to deploy. Thus, this trend towards wireless connectivity will only continue and Sandia must develop the necessary simulation technology to proactively analyze the associated emerging vulnerabilities. Wireless networks are marked by mobility and proximity-based connectivity. The de facto standard for exploratory studies of wireless networks is discrete event simulations (DES). However, the simulation of large-scale wireless networks is extremely difficult due to prohibitively large turnaround time. A path forward is to expedite simulations with parallel discrete event simulation (PDES) techniques. The mobility and distance-based connectivity associated with wireless simulations, however, typically doom PDES and fail to scale (e.g., OPNET and ns-3 simulators). We propose a PDES-based tool aimed at reducing the communication overhead between processors. The proposed solution will use light-weight processes to dynamically distribute computation workload while mitigating communication overhead associated with synchronizations. This work is vital to the analytics and validation capabilities of simulation and emulation at Sandia. We have years of experience in Sandia’s simulation and emulation projects (e.g., MINIMEGA and FIREWHEEL). Sandia’s current highly-regarded capabilities in large-scale emulations have focused on wired networks, where two assumptions prevent scalable wireless studies: (a) the connections between objects are mostly static and (b) the nodes have fixed locations.

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TYPE Other Report YEAR 2015
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High Fidelity Simulations of Large-Scale Wireless Networks (Plus-Up)

Onunkwo, Uzoma

Sandia has built a strong reputation in scalable network simulation and emulation for cyber security studies to protect our nation’s critical information infrastructures. Georgia Tech has preeminent reputation in academia for excellence in scalable discrete event simulations, with strong emphasis on simulating cyber networks. Many of the experts in this field, such as Dr. Richard Fujimoto, Dr. George Riley, and Dr. Chris Carothers, have strong affiliations with Georgia Tech. The collaborative relationship that we intend to immediately pursue is in high fidelity simulations of practical large-scale wireless networks using ns-3 simulator via Dr. George Riley. This project will have mutual benefits in bolstering both institutions’ expertise and reputation in the field of scalable simulation for cyber-security studies. This project promises to address high fidelity simulations of large-scale wireless networks. This proposed collaboration is directly in line with Georgia Tech’s goals for developing and expanding the Communications Systems Center, the Georgia Tech Broadband Institute, and Georgia Tech Information Security Center along with its yearly Emerging Cyber Threats Report. At Sandia, this work benefits the defense systems and assessment area with promise for large-scale assessment of cyber security needs and vulnerabilities of our nation’s critical cyber infrastructures exposed to wireless communications.

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TYPE Other Report YEAR 2015
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Methodology for assessing the safety of Hydrogen Systems: HyRAM 1.0 technical reference manual

Groth, Katrina M.; Hecht, Ethan S.; Reynolds, John

The HyRAM software toolkit provides a basis for conducting quantitative risk assessment and consequence modeling for hydrogen infrastructure and transportation systems. HyRAM is designed to facilitate the use of state-of-the-art science and engineering models to conduct robust, repeatable assessments of hydrogen safety, hazards, and risk. HyRAM is envisioned as a unifying platform combining validated, analytical models of hydrogen behavior, a standardized, transparent QRA approach, and engineering models and generic data for hydrogen installations. HyRAM is being developed at Sandia National Laboratories for the U. S. Department of Energy to increase access to technical data about hydrogen safety and to enable the use of that data to support development and revision of national and international codes and standards. This document provides a description of the methodology and models contained in the HyRAM version 1.0. HyRAM 1.0 includes generic probabilities for hydrogen equipment failures, probabilistic models for the impact of heat flux on humans and structures, and computationally and experimentally validated analytical and first order models of hydrogen release and flame physics. HyRAM 1.0 integrates deterministic and probabilistic models for quantifying accident scenarios, predicting physical effects, and characterizing hydrogen hazards (thermal effects from jet fires, overpressure effects from deflagrations), and assessing impact on people and structures. HyRAM is a prototype software in active development and thus the models and data may change. This report will be updated at appropriate developmental intervals.

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TYPE SAND Report YEAR 2015
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A Best Practice for Developing Availability Guarantee Language in Photovoltaic (PV) O&M Agreements

Klise, Geoffrey T.; Balfour, John

This document outlines the foundation for developing language that can be utilized in an Equipment Availability Guarantee, typically included in an O&M services agreement between a PV system or plant owner and an O&M services provider, or operator. Many of the current PV O&M service agreement Availability Guarantees are based on contracts used for traditional power generation, which create challenges for owners and operators due to the variable nature of grid-tied photovoltaic generating technologies. This report documents language used in early PV availability guarantees and presents best practices and equations that can be used to more openly communicate how the reliability of the PV system and plant equipment can be expressed in an availability guarantee. This work will improve the bankability of PV systems by providing greater transparency into the equipment reliability state to all parties involved in an O&M services contract.

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TYPE SAND Report YEAR 2015
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On Radar Resolution in Coherent Change Detection

Bickel, Douglas L.

It is commonly observed that resolution plays a role in coherent change detection. Although this is the case, the relationship of the resolution in coherent change detection is not yet defined . In this document, we present an analytical method of evaluating this relationship using detection theory. Specifically we examine the effect of resolution on receiver operating characteristic curves for coherent change detection.

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TYPE SAND Report YEAR 2015
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Climate Induced Spillover and Implications for U.S. Security

Tidwell, Vincent C.; Naugle, Asmeret B.; Backus, George A.; Lott, Kathryn M.; Keller, Elizabeth; Kobos, Peter; Villa, Daniel L.

Developing nations incur a greater risk to climate change than the developed world due to poorly managed human/natural resources, unreliable infrastructure and brittle governing/economic institutions. These vulnerabilities often give rise to a climate induced “domino effect” of reduced natural resource production-leading to economic hardship, social unrest, and humanitarian crises. Integral to this cascading set of events is increased human migration, leading to the “spillover” of impacts to adjoining areas with even broader impact on global markets and security. Given the complexity of factors influencing human migration and the resultant spill-over effect, quantitative tools are needed to aid policy analysis. Toward this need, a series of migration models were developed along with a system dynamics model of the spillover effect. The migration decision models were structured according to two interacting paths, one that captured long-term “chronic” impacts related to protracted deteriorating quality of life and a second focused on short-term “acute” impacts of disaster and/or conflict. Chronic migration dynamics were modeled for two different cases; one that looked only at emigration but at a national level for the entire world; and a second that looked at both emigration and immigration but focused on a single nation. Model parameterization for each of the migration models was accomplished through regression analysis using decadal data spanning the period 1960-2010. A similar approach was taken with acute migration dynamics except regression analysis utilized annual data sets limited to a shorter time horizon (2001-2013). The system dynamics spillover model was organized around two broad modules, one simulating the decision dynamics of migration and a second module that treats the changing environmental conditions that influence the migration decision. The environmental module informs the migration decision, endogenously simulating interactions/changes in the economy, labor, population, conflict, water, and food. A regional model focused on Mali in western Africa was used as a test case to demonstrate the efficacy of the model.

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TYPE SAND Report YEAR 2015
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Dynamic Analytical Capability to Better Understand and Anticipate Extremist Shifts Within Populations under Authoritarian Regimes

Bernard, Michael

The purpose of this work is to create a generalizable data- and theory-supported capability to better understand and anticipate (with quantifiable uncertainty): 1) how the dynamics of allegiance formations between various groups and society are impacted by active conflict and by third-party interventions and 2) how/why extremist allegiances co-evolve over time due to changing geopolitical, sociocultural, and military conditions.

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TYPE Other Report YEAR 2015
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Test Plan for the Boiling Water Reactor Dry Cask Simulator

Durbin, S.; Lindgren, Eric

The thermal performance of commercial nuclear spent fuel dry storage casks are evaluated through detailed numerical analysis . These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full sized casks or smaller cask analogs are widely recognized as vital for validating these models. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask in part by increasing the efficiency of internal conduction pathways and by increasing the internal convection through greater canister helium pressure. These same vertical, canistered cask systems rely on ventilation between the canister and the overpack to convect heat away from the canister to the environment for both above and below-ground configurations. While several testing programs have been previously conducted, these earlier validation attempts did not capture the effects of elevated helium pressures or accurately portray the external convection of above-ground and below-ground canistered dry cask systems. The purpose of the investigation described in this report is to produce a data set that can be used to test the validity of the assumptions associated with the calculations presently used to determine steady-state cladding temperatures in modern vertical, canistered dry cask systems. The BWR cask simulator (BCS) has been designed in detail for both the above-ground and below-ground venting configurations. The pressure vessel representing the canister has been designed, fabricated, and pressure tested for a maximum allowable pressure (MAWP) rating of 24 bar at 400 deg C. An existing electrically heated but otherwise prototypic BWR Incoloy-clad test assembly is being deployed inside of a representative storage basket and cylindrical pressure vessel that represents the canister. The symmetric single assembly geometry with well-controlled boundary conditions simplifies interpretation of results. Various configurations of outer concentric ducting will be used to mimic conditions for above and below-ground storage configurations of vertical, dry cask systems with canisters. Radial and axial temperature profiles will be measured for a wide range of decay power and helium cask pressures. Of particular interest is the evaluation of the effect of increased helium pressure on allowable heat load and the effect of simulated wind on a simplified below ground vent configuration. While incorporating the best available information, this test plan is subject to changes due to improved understanding from modeling or from as-built deviations to designs. As-built conditions and actual procedures will be documented in the final test report.

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TYPE SAND Report YEAR 2015
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Exploring magnetized liner inertial fusion with a semi-analytic model

Mcbride, Ryan; Slutz, Stephen A.; Sinars, Daniel; Vesey, Roger A.; Gomez, Matthew R.; Sefkow, Adam B.; Hansen, Stephanie B.; Cochrane, Kyle; Schmit, Paul; Knapp, P.F.; Geissel, Matthias; Harvey-Thompson, Adam J.; Jennings, Christopher A.; Martin, Matthew R.; Awe, Thomas J.; Rovang, Dean C.; Lamppa, Derek C.; Peterson, K.J.; Rochau, G.A.; Porter, John L.; Stygar, William A.; Cuneo, Michael E.

Abstract not provided.

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TYPE Conference Poster YEAR 2015
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Results 45201–45300 of 99,299
Results 45201–45300 of 99,299