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Fukushima Daiichi Unit 1 Uncertainty Analysis-Exploration of Core Melt Progression Uncertain Parameters-Volume II

Denman, Matthew R.; Brooks, Dusty M.

Sandia National Laboratories (SNL) has conducted an uncertainty analysis (UA) on the Fukushima Daiichi unit (1F1) accident progression with the MELCOR code. Volume I of the 1F1 UA discusses the physical modeling details and time history results of the UA. Volume II of the 1F1 UA discusses the statistical viewpoint. The model used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). The goal of this work was to perform a focused evaluation of uncertainty in core damage progression behavior and its effect on key figures-ofmerit (e.g., hydrogen production, fraction of intact fuel, vessel lower head failure) and in doing so assess the applicability of traditional sensitivity analysis techniques.

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TYPE SAND Report YEAR 2015
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NetMOD Version 2.0 Mathematical Framework

Merchant, Bion J.

NetMOD (Network Monitoring for Optimal Detection) is a Java-based software package for conducting simulation of seismic, hydroacoustic and infrasonic networks. Network simulations have long been used to study network resilience to station outages and to determine where additional stations are needed to reduce monitoring thresholds. NetMOD makes use of geophysical models to determine the source characteristics, signal attenuation along the path between the source and station, and the performance and noise properties of the station. These geophysical models are combined to simulate the relative amplitudes of signal and noise that are observed at each of the stations. From these signal-to-noise ratios (SNR), the probabilities of signal detection at each station and event detection across the network of stations can be computed given a detection threshold. The purpose of this document is to clearly and comprehensively present the mathematical framework used by NetMOD, the software package developed by Sandia National Laboratories to assess the monitoring capability of ground-based sensor networks. Many of the NetMOD equations used for simulations are inherited from the NetSim network capability assessment package developed in the late 1980s by SAIC (Sereno et al., 1990).

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TYPE SAND Report YEAR 2015
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NetMOD Version 2.0 Parameters

Merchant, Bion J.

NetMOD (Network Monitoring for Optimal Detection) is a Java-based software package for conducting simulation of seismic, hydroacoustic and infrasonic networks. Network simulations have long been used to study network resilience to station outages and to determine where additional stations are needed to reduce monitoring thresholds. NetMOD makes use of geophysical models to determine the source characteristics, signal attenuation along the path between the source and station, and the performance and noise properties of the station. These geophysical models are combined to simulate the relative amplitudes of signal and noise that are observed at each of the stations. From these signal-to-noise ratios (SNR), the probability of detection can be computed given a detection threshold. This document describes the parameters that are used to configure the NetMOD tool and the input and output parameters that make up the simulation definitions.

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TYPE SAND Report YEAR 2015
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MELCOR Computer Code Manuals Volume 1: Primer and Users' Guide

Humphries, Larry L.; Figueroa Faria, Victor G.; Young, Michael F.; Foulk, James W.; Reynolds, John

MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. MELCOR is being developed at Sandia National Laboratories for the U.S. Nuclear Regulatory Commission as a second-generation plant risk assessment tool and the successor to the Source Term Code Package. A broad spectrum of severe accident phenomena in both boiling and pressurized water reactors is treated in MELCOR in a unified framework. These include thermal-hydraulic response in the reactor coolant system, reactor cavity, containment, and confinement buildings; core heatup, degradation, and relocation; core-concrete attack; hydrogen production, transport, and combustion; fission product release and transport behavior. Current uses of MELCOR include estimation of severe accident source terms and their sensitivities and uncertainties in a variety of applications.

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TYPE Other Report YEAR 2015
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MELCOR Computer Code Manuals

Humphries, Larry L.; Figueroa Faria, Victor G.; Young, Michael F.; Foulk, James W.; Reynolds, John

MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. MELCOR is being developed at Sandia National Laboratories for the U.S. Nuclear Regulatory Commission as a second-generation plant risk assessment tool and the successor to the Source Term Code Package. A broad spectrum of severe accident phenomena in both boiling and pressurized water reactors is treated in MELCOR in a unified framework. These include thermal-hydraulic response in the reactor coolant system, reactor cavity, containment, and confinement buildings; core heatup, degradation, and relocation; core-concrete attack; hydrogen production, transport, and combustion; fission product release and transport behavior. Current uses of MELCOR include estimation of severe accident source terms and their sensitivities and uncertainties in a variety of applications.

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TYPE Other Report YEAR 2015
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Can symmetry transitions of complex fields enable 3-d control of fluid vorticity?

Martin, James E.; Solis, Kyle J.

Methods of inducing vigorous noncontact fluid flow are important to technologies involving heat and mass transfer and fluid mixing, since they eliminate the need for moving parts, pipes and seals, all of which compromise system reliability. Unfortunately, traditional noncontact flow methods are few, and have limitations of their own. We have discovered two classes of fields that can induce fluid vorticity without requiring either gravity or a thermal gradient. The first class we call Symmetry-Breaking Rational Fields. These are triaxial fields comprised of three orthogonal components, two ac and one dc. The second class is Rational Triad Fields, which differ in that all three components are alternating. In this report we quantify the induced vorticity for a wide variety of fields and consider symmetry transitions between these field types. These transitions give rise to orbiting vorticity vectors, a technology for non-contact, non-stationary fluid mixing.

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TYPE SAND Report YEAR 2015
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Photovoltaic System Modeling: Uncertainty and Sensitivity Analyses

Hansen, Clifford; Martin, Curtis E.

We report an uncertainty and sensitivity analysis for modeling AC energy from photovoltaic systems. Output from a PV system is predicted by a sequence of models. We quantify uncertainty in the output of each model using empirical distributions of each model’s residuals. We propagate uncertainty through the sequence of models by sampling these distributions to obtain an empirical distribution of a PV system’s output. We consider models that: (1) translate measured global horizontal, direct and global diffuse irradiance to plane-of-array irradiance; (2) estimate effective irradiance; (3) predict cell temperature; (4) estimate DC voltage, current and power; (5) reduce DC power for losses due to inefficient maximum power point tracking or mismatch among modules; and (6) convert DC to AC power. Our analysis considers a notional PV system comprising an array of FirstSolar FS-387 modules and a 250 kW AC inverter; we use measured irradiance and weather at Albuquerque, NM. We found the uncertainty in PV system output to be relatively small, on the order of 1% for daily energy. We found that uncertainty in the models for POA irradiance and effective irradiance to be the dominant contributors to uncertainty in predicted daily energy. Our analysis indicates that efforts to reduce the uncertainty in PV system output predictions may yield the greatest improvements by focusing on the POA and effective irradiance models.

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TYPE SAND Report YEAR 2015
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Selecting RMF Controls for National Security Systems

Witzke, Edward L.

In 2014, the United States Department of Defense started transitioning the way it performs risk management and accreditation of information systems to a process entitled Risk Management Framework for DoD Information Technology or RMF for DoD IT. There are many more security and privacy controls (and control enhancements) from which to select in RMF, than there were in the previous Information Assurance process. This report is an attempt to clarify the way security controls and enhancements are selected. After a brief overview and comparison of RMF for DoD IT with the previously used process, this report looks at the determination of systems as National Security Systems (NSS). Once deemed to be an NSS, this report addresses the categorization of the information system with respect to impact levels of the various security objectives and the selection of an initial baseline of controls. Next, the report describes tailoring the controls through the use of overlays and scoping considerations. Finally, the report discusses organization-defined values for tuning the security controls to the needs of the information system.

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TYPE SAND Report YEAR 2015
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Deep Borehole Emplacement Mode Hazard Analysis (Rev. 1)

Sevougian, Stephen D.

This report outlines a methodology and provides resource information for the Deep Borehole Emplacement Mode Hazard Analysis (DBEMHA). The main purpose is identify the accident hazards and accident event sequences associated with the two emplacement mode options (wireline or drillstring), to outline a methodology for computing accident probabilities and frequencies, and to point to available databases on the nature and frequency of accidents typically associated with standard borehole drilling and nuclear handling operations.

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TYPE SAND Report YEAR 2015
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Causal Analysis For Occurrence Report: OR NA-SS-SNL-2000-2015-0005 Unexpected Type of Failure of Thermal Battery

Forbes, Elizabeth H.

On 6/26/2015 at approximately 1445 in 894/136, a pulse thermal battery (approximately the size of a commercial size C cell) experienced an unexpected failure following an electrical performance test that is routinely conducted on thermal batteries. A dedicated tester for this operation was used and it ran the test until the nominal 28-volt output of the battery had dropped to 5 volts, usually indicative of the battery being spent and safe enough to move. The failure occurred while a test operator was transferring the battery from the testing primary containment box to another primary containment box within the same room; initial indications are that the battery experienced an over-pressurization failure which led to the battery's base plate being expelled and the operator receiving a non-recordable injury (bruising to the palm of the hand) from the pressure of the expulsion. The operator was wearing the prescribed PPE (safety glasses and high temperature glove) and was handling the battery appropriately with an open, flat hand. Pictures of the scene are below.

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TYPE Other Report YEAR 2015
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Sulphur Extraction at Bryan Mound

Kirby, Carolyn L.; Lord, Anna S.

The Bryan Mound caprock was subjected to extensive sulphur mining prior to the development of the Strategic Petroleum Reserve. Undoubtedly, the mining has modified the caprock integrity. Cavern wells at Bryan Mound have been subject to a host of well integrity concerns with many likely compromised by the cavernous caprock, surrounding corrosive environment (H2SO4), and associated elevated residual temperatures all of which are a product of the mining activities. The intent of this study was to understand the sulphur mining process and how the mining has affected the stability of the caprock and how the compromised caprock has influenced the integrity of the cavern wells. After an extensive search to collect pertinent information through state agencies, literature searches, and the Sandia SPR library, a better understanding of the caprock can be inferred from the knowledge gained. Specifically, the discovery of the original ore reserve map goes a long way towards modeling caprock stability. In addition the gained knowledge of sulphur mining – subsidence, superheated corrosive waters, and caprock collapse - helps to better predict the post mining effects on wellbore integrity.

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TYPE SAND Report YEAR 2015
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Determining Reduced Order Models for Optimal Stochastic Reduced Order Models

Bonney, Matthew S.; Brake, M.R.W.

The use of parameterized reduced order models(PROMs) within the stochastic reduced order model (SROM) framework is a logical progression for both methods. In this report, five different parameterized reduced order models are selected and critiqued against the other models along with truth model for the example of the Brake-Reuss beam. The models are: a Taylor series using finite difference, a proper orthogonal decomposition of the the output, a Craig-Bampton representation of the model, a method that uses Hyper-Dual numbers to determine the sensitivities, and a Meta-Model method that uses the Hyper-Dual results and constructs a polynomial curve to better represent the output data. The methods are compared against a parameter sweep and a distribution propagation where the first four statistical moments are used as a comparison. Each method produces very accurate results with the Craig-Bampton reduction having the least accurate results. The models are also compared based on time requirements for the evaluation of each model where the Meta- Model requires the least amount of time for computation by a significant amount. Each of the five models provided accurate results in a reasonable time frame. The determination of which model to use is dependent on the availability of the high-fidelity model and how many evaluations can be performed. Analysis of the output distribution is examined by using a large Monte-Carlo simulation along with a reduced simulation using Latin Hypercube and the stochastic reduced order model sampling technique. Both techniques produced accurate results. The stochastic reduced order modeling technique produced less error when compared to an exhaustive sampling for the majority of methods.

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TYPE SAND Report YEAR 2015
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Chemically Etched Silicon Nanowires as Anodes for Lithium-Ion Batteries

Height, Hannah E.

This study focused on silicon as a high capacity replacement anode for Lithium-ion batteries. The challenge of silicon is that it expands ~270% upon lithium insertion which causes particles of silicon to fracture, causing the capacity to fade rapidly. To account for this expansion chemically etched silicon nanowires from the University of Maine were studied as anodes. They were built into electrochemical half-cells and cycled continuously to measure the capacity and capacity fade.

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TYPE Other Report YEAR 2015
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International scientific collaboration: the Gulf Nuclear Energy Infrastructure Institute

APS FIP Newsletter

Mohagheghi, Amir H.; Williams, Adam D.; Beeley, Phillip A.; Solodov, Alexander

The Gulf Nuclear Energy Infrastructure Institute (GNEII) was established collaboratively by Sandia National Laboratories, Texas A&M University, and the United Arab Emirates’ (UAE’s) Khalifa University of Science, Technology and Research in 2011 to provide a regional mechanism for developing responsible nuclear energy infrastructure. By combining education and research, GNEII helps increase knowledge and expertise about nuclear energy infrastructure—including safety, safeguards, and security—among Gulf and Middle East professionals working in regional nuclear-power programs. GNEII has been recognized by the White House as a major achievement in enhanced science and technology partnerships with the developing world.

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TYPE Journal Article YEAR 2015
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Results 46601–46800 of 99,299
Results 46601–46800 of 99,299