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Biosecurity through Public Health System Design

Beyeler, Walter E.; Finley, Patrick D.; Arndt, William; Walser, Alex C.; Mitchell, Michael D.

We applied modeling and simulation to examine the real-world tradeoffs between developingcountry public-health improvement and the need to improve the identification, tracking, and security of agents with bio-weapons potential. Traditionally, the international community has applied facility-focused strategies for improving biosecurity and biosafety. This work examines how system-level assessments and improvements can foster biosecurity and biosafety. We modeled medical laboratory resources and capabilities to identify scenarios where biosurveillance goals are transparently aligned with public health needs, and resource are distributed in a way that maximizes their ability to serve patients while minimizing security a nd safety risks. Our modeling platform simulates key processes involved in healthcare system operation, such as sample collection, transport, and analysis at medical laboratories. The research reported here extends the prior art by provided two key compone nts for comparative performance assessment: a model of patient interaction dynamics, and the capability to perform uncertainty quantification. In addition, we have outlined a process for incorporating quantitative biosecurity and biosafety risk measures. Two test problems were used to exercise these research products examine (a) Systemic effects of technological innovation and (b) Right -sizing of laboratory networks.

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TYPE Other Report YEAR 2016
DOIOSTI

Storm Water Data 10-27-2016 for Upload to State Database

Holland, Robert C.

In the California Industrial General Permit (IGP) 2014-0057-DWQ for storm water monitoring, effective July 1, 2015, there are 21 contaminants that have been assigned NAL (Numeric Action Level) values, both annual and instantaneous. For annual NALs, an exceedance occurs when the average of all analytical results from all samples taken at a facility during a reporting year for a given parameter exceeds an annual NAL value listed in Table 2 of the General Permit. For instantaneous maximum NALs, an exceedance occurs when two or more analytical results from samples taken for any parameter within a reporting year exceed the instantaneous maximum NAL value (for TSS and O&G), or are outside of the instantaneous maximum NAL range (for pH) listed in Table 2. Table 2 is attached here for your review.

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TYPE Other Report YEAR 2016
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IC Post-Doctoral Fellowship Abstract and Bio

Lacey, Randy

Whole cell biosensors (WCBs) utilize an organism’s natural ability to sense and respond to the environment. Through implementation of two different protein engineering methods, I seek to develop a WCB for the detection of important chemical signatures in the environment. I will reengineer the ligand binding profile of proteins known to alter transcription of genes, and I will engineer signal transduction in proteins already known to bind relevant compounds. In both cases, detection of compounds of interest will lead to the production of a measurable fluorescent signal within the organism. These approaches will provide the groundwork for the development of novel chemical sensing technologies that provide a cheap and efficient alternative to traditional methods for detection of compounds.

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TYPE Other Report YEAR 2016
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AE Recorder Characteristics and Development

Partridge, Michael E.; Curtis, Shane; Mcgrogan, David P.

The Anomalous Environment Recorder (AE Recorder) provides a robust data recording capability for multiple high-shock applications including earth penetrators. The AE Recorder, packaged as a 2.4" di ameter cylinder 3" tall, acquires 12 accelerometer, 2 auxiliary, and 6 discrete signal channels at 250k samples / second. Recording depth is 213 seconds plus 75ms of pre-trigger data. The mechanical, electrical, and firmware are described as well as support electro nics designed for the first use of the recorder.

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TYPE SAND Report YEAR 2016
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A new approach to entangling neutral atoms

Biedermann, Grant

Our team has developed a new approach to entangling neutral atoms with a Rydberg-dressed interaction. Entangling neutral atoms is an essential key of quantum technologies such as quantum computation, many-body quantum simulation, and high-precision atomic sensors . The demonstrated Rydberg-dressed protocol involves adiabatically imposing a light shift on the ground state by coupling an excited Rydberg state with a tuned laser field. Using this technique, we have demonstrated a strong and tunable dipole - dipole interaction between two individually trapped atoms with energy shifts of order 1 MHz, which has been challenging to achieve in other protocols . During this program, we experimentally demonstrated Bell-state entanglement and the isomorphism to the Jaynes - Cumming model of a Rydberg-dressed two-atom system. Our theoretical calculations of a CPHASE quantum logic gate and arbitrary Dicke state quantum control in this system encourage further work.

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TYPE SAND Report YEAR 2016
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Foundations for Protecting Renewable-Rich Distribution Systems

Ellis, Abraham; Brahma, Sukumar; Ranade, Satish

High proliferation of Inverter Interfaced Distributed Energy Resources (IIDERs) into the electric distribution grid introduces new challenges to protection of such systems. This is because the existing protection systems are designed with two assumptions: 1) system is single-sourced, resulting in unidirectional fault current, and (2) fault currents are easily detectable due to much higher magnitudes compared to load currents. Due to the fact that most renewables interface with the grid though inverters, and inverters restrict their current output to levels close to the full load currents, both these assumptions are no longer valid - the system becomes multi-sourced, and overcurrent-based protection does not work. The primary scope of this study is to analyze the response of a grid-tied inverter to different faults in the grid, leading to new guidelines on protecting renewable-rich distribution systems.

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TYPE Other Report YEAR 2016
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MELCOR/CONTAIN LMR Implementation Report - FY16 Progress

Bays, Nathan R.; Humphries, Larry L.

This report describes the progress of the CONTAIN - LMR sodium physics and chemistry models to be implemented in MELCOR 2.1. In the past three years , the implementation included the addition of sodium equations of state and sodium properties from two different sources. The first source is based on the previous work done by Idaho National Laboratory by modifying MELCOR to include liquid lithium equation of state as a working fluid to model the nuclear fusion safety research. The second source uses properties generated for the SIMMER code. The implemented modeling has been tested and results are reported in this document. In addition, the CONTAIN - LMR code was derived from an early version of the CONTAIN code, and many physical models that were developed since this early version of CONTAIN are not available in this early code version. Therefore, CONTAIN 2 has been updated with the sodium models in CONTAIN - LMR as CONTAIN2 - LMR, which may be used to provide code-to-code comparison with CONTAIN - LMR and MELCOR when the sodium chemistry models from CONTAIN - LMR have been completed. Both the spray fire and pool fire chemistry routines from CONTAIN - LMR have been integrated into MELCOR 2.1, and debugging and testing are in progress. Because MELCOR only models the equation of state for liquid and gas phases of the coolant, a modeling gap still exists when dealing with experiments or accident conditions that take place when the ambient temperature is below the freezing point of sodium. An alternative method is under investigation to overcome this gap . We are no longer working on the separate branch from the main branch of MELCOR 2.1 since the major modeling of MELCOR 2.1 has been completed. At the current stage, the newly implemented sodium chemistry models will be a part of the main MELCOR release version (MELCOR 2.2). This report will discuss the accomplishments and issues relating to the implementation. Also, we will report on the planned completion of all remaining tasks in the upcoming FY2017, including the atmospheric chemistry model and sodium - concrete interaction model implementation .

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TYPE SAND Report YEAR 2016
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Correlation of Noise Signature to Pulsed Power Events at the HERMES III Accelerator

Lewis, Barbara; Joseph, Nathan; Salazar, J.D.

The HERMES III accelerator, which is located at Sandia National Laboratories' Tech Area IV, is the largest pulsed gamma X-ray source in the world. The accelerator is made up of 20 inductive cavities that are charged to 1 MV each by complex pulsed power circuitry. The firing time of the machine components ranges between the microsecond and nanosecond timescales. This results in a variety of electromagnetic frequencies when the accelerator fires. Testing was done to identify the HERMES electromagnetic noise signal and to map it to the various accelerator trigger events. This report will show the measurement methods used to capture the noise spectrum produced from the machine and correlate this noise signature with machine events.

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TYPE SAND Report YEAR 2016
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Energy Transfer of a Shaped Charge

Milinazzo, Jared J.

A cylinder of explosive with a hollow cavity on one and a detonator at the other is considered a hollow charge. When the explosive is detonated the detonation products form a localized intense force. If the hollow charge is placed near or in contact with a steel plate then the damage to the plate is greater than a solid cylinder of explosive even though there is a greater amount of explosive in the latter charge. The hollow cavity can take almost any geometrical shape with differing amounts of damage associated with each shape. This phenomenon is known in the United States as the Munroe effect.

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TYPE Other Report YEAR 2016
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NSRD-11: Computational Capability to Substantiate DOE-HDBK-3010 Data

Bays, Nathan R.; Brown, Alexander L.; Gelbard, Fred M.; Bignell, John; Pierce, Flint; Voskuilen, Tyler; Rodriguez, Salvador B.; Dingreville, Remi P.M.; Zepper, Ethan T.; Juan, Pierre-Alexandre; San LeSan; Gilkey, Lindsay N.

Safety basis analysts throughout the U.S. Department of Energy (DOE) complex rely heavily on the information provided in the DOE Handbook, DOE - HDBK - 3010, Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, to determine radionuclide source terms. In calculating source terms, analysts tend to use the DOE Handbook's bounding values on airborne release fractions (ARFs) and respirable fractions (RFs) for various categories of insults (representing potential accident release categories). This is typically due to both time constraints and the avoidance of regulatory critique. Unfortunately, these bounding ARFs/RFs represent extremely conservative values. Moreover, they were derived from very limited small-scale bench/laboratory experiments and/or from engineered judgment. Thus, the basis for the data may not be representative of the actual unique accident conditions and configurations being evaluated. The goal of this research is to develop a more accurate and defensible method to determine bounding values for the DOE Handbook using state-of-art multi-physics-based computer codes. This enables us to better understand the fundamental physics and phenomena associated with the types of accidents in the handbook. In this year, this research included improvements of the high-fidelity codes to model particle resuspension and multi-component evaporation for fire scenarios. We also began to model ceramic fragmentation experiments, and to reanalyze the liquid fire and powder release experiments that were done last year. The results show that the added physics better describes the fragmentation phenomena. Thus, this work provides a low-cost method to establish physics-justified safety bounds by taking into account specific geometries and conditions that may not have been previously measured and/or are too costly to perform.

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TYPE SAND Report YEAR 2016
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Pulsed Power and SF6

Mckee, G.R.

The Z Machine began operation in 1985 as the Particle Beam Fusion Accelerator 2 (PBFA-II). It was built as a high voltage driver to generate light ion beams in support of the Inertial Confinement Fusion (ICF) Program. In 1996 PBFA-II was converted to a high current mode to investigate recent advances in imploding wire-array X-ray generation that Sandia scientists had made at the Saturn facility. Sandia planned to split the machine’s time between the high voltage ion beam mode and the high current X-ray generation mode, but the initial tests were so successful the machine was kept in the high current configuration. The machine was renamed the ‘Z Machine’ and scientists developed a number of experimental uses for the extremely high current outputs of Z, including dynamic material studies and the Isentropic Compression Experiments (ICE). In 2007 the Z Machine was refurbished to update machine components, many of which were original to the 1985 PBFA-II configuration. During the refurbishment project new technological improvements were incorporated nearly doubling the output power of the machine without increasing its overall size.

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TYPE Other Report YEAR 2016
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UVI ThunnderBird Cup v2.0 Workshop: Worshop Analysis 2016

Lee, Wellington K.; Morris, Tyler; Chu, Andrew C.; Russ, Joshua; Emerson-Lewis, Michelle

The ThunderBird Cup v2.0 (TBC2) program falls under the Minority Serving Institution Pipeline Program (MSIPP) that aims to establish a world-class workforce development, education and research program that combines the strengths of Historically Black Colleges and Universities (HBCUs) and national laboratories to create a K-20 pipeline of students to participate in cybersecurity and related fields.

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TYPE Other Report YEAR 2016
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ABQ ThunderBird Cup v3.0 Alpha Worksop: Workshop Analysis 2016

Lee, Wellington K.; Gilmore, Katrina; Russ, Joshua; Carter, Aliyah

The ThunderBird Cup v3.0 (TBC3) program falls under the Minority Serving Institution Pipeline Program (MSIPP) that aims to establish a world-class workforce development, education and research program that combines the strengths of Historically Black Colleges and Universities (HBCUs) and national laboratories to create a K-20 pipeline of students to participate in cybersecurity and related fields.

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TYPE Other Report YEAR 2016
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Laser Rewelding of 304L Stainless Steel

Maguire, Michael C.; Rodelas, Jeffrey

Laser welding of 304L stainless steel during component fabrication has been found to alter the chemical composition of the steel due to material evaporation. During repair or rework, or during potential reuse/ rewelding of certain components, the potential exists to alter the composition to the extent that the material becomes prone to solidification cracking. This work aims to characterize the extent of this susceptibility in order to make informed decisions regarding rewelding practice and base metal chemistry allowances.

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TYPE Other Report YEAR 2016
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The Design Fabrication Installation & Evaluation of the Balance Probe Monitor for Large Centrifuges at a National Laboratory Facility

Gallegos, Jonathan M.

Balance Probe Monitors were designed, fabricated, installed, and evaluated at Sandia National Laboratories (SNL) for the 22,600 g kg (50,000 g lb) direct drive electromotor driven large centrifuges. These centrifuges provide a high onset/decay rate g environment. The Balance Probe Monitor is physically located near a centrifuge’s Capacitance Probe, a crucial sensor for the centrifuge’s sustainability. The Balance Probe Monitor will validate operability of the centrifuge. Most importantly, it is used for triggering a kill switch under the condition that the centrifuge displacement value exceeds allowed tolerances. During operational conditions, the Capacitance Probe continuously detects the structural displacement of the centrifuge and an adjoining AccuMeasure 9000 translates this displacement into an output voltage.

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TYPE Other Report YEAR 2016
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Analysis of 2016 Occurrence Reports Involving Electrical Energy

Wright, Paul C.; Tryon, Arthur E.

The 04100 Center Director requested an analysis of 2016 occurrence reports (ORs) involving electrical energy be performed to facilitate learning through use of performance assurance methodologies. Preliminarily, 11 reportable events were identified for review; however, this population was updated to 12 during the review. Appendix 1 includes the analysis protocol and a listing of the ORs reviewed. The Team completed its review at the end of October 2016. At that time, causal analysis and associated corrective action information was available for eight events. Elements of this analysis included determining the following: common weaknesses that contributed to electrical events; the quality of causal analysis products with the goal of providing sustainable long-term corrective actions; and how learning from issues, causes, and corrective actions from prior similar events is incorporated into causal analyses for today’s events. As used in this report, the term “trends” was used as a catalyst to determine categories of events for deeper analysis. The content of ORs is important. The information in an OR for a past event can be useful in addressing today’s issues because it provides information on systemic issues that were found and past actions addressing those issues. The effectiveness of those actions as viewed from today’s vantage point is useful input to the determination of corrective actions for current problems. Additionally, as a means of communication to DOE and NNSA, ORs provide a measure of Sandia’s maturity in understanding problems and their solutions.

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TYPE SAND Report YEAR 2016
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An Overview of Chain of Custody Options for LETTERPRESS

Smartt, Heidi A.

This purpose of this document is to provide an overview of Chain of Custody (CoC) technology options that could be made available for the LETTERPRESS exercise as part of the Quad Working Group. The Quad Working Group comprises five sub-working groups (Management, Protocol, Simulation, Technology, and Training) with members from the U.S., U.K., Norway, and Sweden having the goal of providing a repeatable, realistic arms control exercise (dubbed LETTERPRESS) to be executed in representative facilities and using non-proliferative but representative treaty items. The Technology Working Group is responsible for supporting the technology requirements of the LETTERPRESS exercise and as such the technologies presented here are possible options to meet those requirements.

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TYPE Other Report YEAR 2016
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Shock-isolation material selection for electronic packages in hard-target environment

Stotts, Jarrett E.

High velocity munitions and kinetic penetrators experience monumental external forces, impulses, and accelerations. The hard target environment is immensely taxing on sophisticated electronic components and recorders designed to retrieve valuable data related to the systems performance and characteristics in the periods of flight, impact, and post-impact. Such electronic systems have upper limits of overall shock intensity which, if exceeded, will either shorten the operating life of the parts or risk destruction resulting in loss of both the data and the principal value of the recorder. The focus of this project was to refine the categorization of leading material types for encapsulation and passive shock isolation and implement them in a method useable for a wide variety of environments. Namely, a design methodology capable of being tailored to the specific impact conditions to maximize the lively hood of sensitive electronics and the information recorded. The results of the study concluded that the materials observed under consistent dynamic high strain rate tests, which include Conathane® EN-4/9, Slygard®-184, and Stycast™-2651, behaved well in certain aspects of energy transmission and shock when considering the frequency environment or package coupled with the isolation material’s application. Key points about the implementation of the materials in extreme shock environments is discussed with the connection to energy analysis, loss attributes, and pulse transmissibility modeling. However, attempts to model the materials solely based on energy transmissibility in the frequency domain using only external experimental data and simplified boundary conditions was not found to be consistent with that acquired from the pressure bar experiments. Further work will include the addition of further material experimentation of the encapsulants in other frequency and temperature states, confined and pre-load boundary states, and composite constructions.

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TYPE Thesis or Dissertation YEAR 2016
OSTI

Selenite sorption by carbonate substituted apatite

Environmental Pollution

Moore, Robert C.; Rigali, Mark J.; Brady, Patrick V.; Stewart, Thomas A.

The sorption of selenite, SeO32−, by carbonate substituted hydroxylapatite was investigated using batch kinetic and equilibrium experiments. The carbonate substituted hydroxylapatite was prepared by a precipitation method and characterized by SEM, XRD, FT-IR, TGA, BET and solubility measurements. The material is poorly crystalline, contains approximately 9.4% carbonate by weight and has a surface area of 210.2 m2/g. Uptake of selenite by the carbonated hydroxylapatite was approximately an order of magnitude higher than the uptake by uncarbonated hydroxylapatite reported in the literature. Distribution coefficients, Kd, determined for the carbonated apatite in this work ranged from approximately 4200 to over 14,000 L/kg. A comparison of the results from kinetic experiments performed in this work and literature kinetic data indicates the carbonated apatite synthesized in this study sorbed selenite 23 times faster than uncarbonated hydroxylapatite based on values normalized to the surface area of each material. The results indicate carbonated apatite is a potential candidate for use as a sorbent for pump-and-treat technologies, soil amendments or for use in permeable reactive barriers for the remediation of selenium contaminated sediments and groundwaters.

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TYPE Journal Article YEAR 2016
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Cofactor engineering of ketol-acid reductoisomerase (IlvC) and alcohol dehydrogenase (YqhD) improves the fusel alcohol yield in algal protein anaerobic fermentation

Algal Research

Wu, Weihua W.; Davis, Ryan W.; Tran-Gyamfi, Mary

The feasibility of converting algal protein to mixed alcohols has recently been demonstrated with an engineered E. coli strain, enabling comprehensive utilization of the biomass for biofuel applications. However, the yield and titers of mixed alcohol production must be improved for market adoption. A major limiting factor for achieving the necessary yield and titer improvements is cofactor imbalance during the fermentation of algal protein. To resolve this problem, a directed evolution approach was applied to modify the cofactor specificity of two key enzymes (IlvC and YqhD) from NADPH to NADH in the mixed alcohol metabolic pathway. Using high throughput screening, more than 20 YqhD mutants were identified to show activity on NADH as a cofactor. Of these 20 mutants, the four highest activity YqhD mutants were selected for combination with two IlvC mutants, both accepting NADH as a redox cofactor, for modification of the protein conversion strain. The combination of the IlvC and YqhD mutants yielded a refined E. coli strain, subtype AY3, with increased fusel alcohol yield of ~ 60% compared to wild type under anaerobic fermentation on amino acid mixtures. When applied to real algal protein hydrolysates, the strain AY3 produced 100% and 38% more total mixed alcohols than the wild type strain on two different algal hydrolysates, respectively. The results indicate that cofactor engineering is a promising approach to improve the feasibility of bioconversion of algal protein into mixed alcohols as advanced biofuels.

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TYPE Journal Article YEAR 2016
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Solubility constants of hydroxyl sodalite at elevated temperatures evaluated from hydrothermal experiments: Applications to nuclear waste isolation

Applied Geochemistry

Xiong, Yongliang

In this study, solubility constants of hydroxyl sodalite (ideal formula, Na8[Al6Si6O24][OH]2·3H2O) from 25 °C to 100 °C are obtained by applying a high temperature Al—Si Pitzer model to evaluate solubility data on hydroxyl sodalite in high ionic strength solutions at elevated temperatures. A validation test comparing model-independent experimental data to model predictions demonstrates that the solubility values produced by the model are in excellent agreement with the experimental data. The equilibrium constants obtained in this study have a wide range of applications, including synthesis of hydroxyl sodalite, de-silication in the Bayer process for extraction of alumina, and the performance of proposed sodalite waste forms in geological repositories in various lithologies including salt formations. The thermodynamic calculations based on the equilibrium constants obtained in this work indicate that the solubility products in terms of mΣAl×mΣSi for hydroxyl sodalite are very low (e.g., ∼10–13 [mol·kg–1]2 at 100 °C) in brines characteristic of salt formations, implying that sodalite waste forms would perform very well in repositories located in salt formations. The information regarding the solubility behavior of hydroxyl sodalite obtained in this study provides guidance to investigate the performance of other pure end-members of sodalite such as chloride- and iodide-sodalite, which may be of interest for geological repositories in various media.

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TYPE Journal Article YEAR 2016
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High-flux plasma exposure of ultra-fine grain tungsten

International Journal of Refractory Metals and Hard Materials

Kolasinski, Robert; Buchenauer, D.A.; Doerner, R.P.; Fang, Z.Z.; Ren, C.; Oya, Y.; Michibayashi, K.; Friddle, Raymond W.; Mills, Bernice E.

In this work, we examine the response of an ultra-fine grained (UFG) tungsten material to high-flux deuterium plasma exposure. UFG tungsten has received considerable interest as a possible plasma-facing material in magnetic confinement fusion devices, in large part because of its improved resistance to neutron damage. However, optimization of the material in this manner may lead to trade-offs in other properties. We address two aspects of the problem in this work: (a) how high-flux plasmas modify the structure of the exposed surface, and (b) how hydrogen isotopes become trapped within the material. The specific UFG tungsten considered here contains 100 nm-width Ti dispersoids (1 wt%) that limit the growth of the W grains to a median size of 960 nm. Metal impurities (Fe, Cr) as well as O were identified within the dispersoids; these species were absent from the W matrix. To simulate relevant particle bombardment conditions, we exposed specimens of the W-Ti material to low energy (100 eV), high-flux (> 1022 m− 2 s− 1) deuterium plasmas in the PISCES-A facility at the University of California, San Diego. To explore different temperature-dependent trapping mechanisms, we considered a range of exposure temperatures between 200 °C and 500 °C. For comparison, we also exposed reference specimens of conventional powder metallurgy warm-rolled and ITER-grade tungsten at 300 °C. Post-mortem focused ion beam profiling and atomic force microscopy of the UFG tungsten revealed no evidence of near-surface bubbles containing high pressure D2 gas, a common surface degradation mechanism associated with plasma exposure. Thermal desorption spectrometry indicated moderately higher trapping of D in the material compared with the reference specimens, though still within the spread of values for different tungsten grades found in the literature database. For the criteria considered here, these results do not indicate any significant obstacles to the potential use of UFG tungsten as a plasma-facing material, although further experimental work is needed to assess material response to transient events and high plasma fluence.

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TYPE Journal Article YEAR 2016
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Ray Effect Mitigation Through Reference Frame Rotation

Journal of Heat Transfer

Tencer, John T.

The discrete ordinates method is a popular and versatile technique for solving the radiative transport equation, a major drawback of which is the presence of ray effects. Mitigation of ray effects can yield significantly more accurate results and enhanced numerical stability for combined mode codes. When ray effects are present, the solution is seen to be highly dependent upon the relative orientation of the geometry and the global reference frame. This is an undesirable property. A novel ray effect mitigation technique of averaging the computed solution for various reference frame orientations is proposed.

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TYPE Journal Article YEAR 2016
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Metal-organic frameworks for thermoelectric energy-conversion applications

MRS Bulletin

Talin, Albert A.; Jones, Reese E.

Motivated by low cost, low toxicity, mechanical flexibility, and conformability over complex shapes, organic semiconductors are currently being actively investigated as thermoelectric (TE) materials to replace the costly, brittle, and non-eco-friendly inorganic TEs for near-ambient-temperature applications. Metal-organic frameworks (MOFs) share many of the attractive features of organic polymers, including solution processability and low thermal conductivity. A potential advantage of MOFs and MOFs with guest molecules (Guest@MOFs) is their synthetic and structural versatility, which allows both the electronic and geometric structure to be tuned through the choice of metal, ligand, and guest molecules. This could solve the long-standing challenge of finding stable, high-TE-performance n-type organic semiconductors, as well as promote high charge mobility via the long-range crystalline order inherent in these materials. In this article, we review recent advances in the synthesis of MOF and Guest@MOF TEs and discuss how the Seebeck coefficient, electrical conductivity, and thermal conductivity could be tuned to further optimize TE performance.

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TYPE Journal Article YEAR 2016
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POF-Darts: Geometric adaptive sampling for probability of failure

Reliability Engineering and System Safety

Ebeida, Mohamed S.; Mitchell, Scott A.; Swiler, Laura P.; Romero, Vicente J.; Rushdi, Ahmad A.

We introduce a novel technique, POF-Darts, to estimate the Probability Of Failure based on random disk-packing in the uncertain parameter space. POF-Darts uses hyperplane sampling to explore the unexplored part of the uncertain space. We use the function evaluation at a sample point to determine whether it belongs to failure or non-failure regions, and surround it with a protection sphere region to avoid clustering. We decompose the domain into Voronoi cells around the function evaluations as seeds and choose the radius of the protection sphere depending on the local Lipschitz continuity. As sampling proceeds, regions uncovered with spheres will shrink, improving the estimation accuracy. After exhausting the function evaluation budget, we build a surrogate model using the function evaluations associated with the sample points and estimate the probability of failure by exhaustive sampling of that surrogate. In comparison to other similar methods, our algorithm has the advantages of decoupling the sampling step from the surrogate construction one, the ability to reach target POF values with fewer samples, and the capability of estimating the number and locations of disconnected failure regions, not just the POF value. We present various examples to demonstrate the efficiency of our novel approach.

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TYPE Journal Article YEAR 2016
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Modeling the measured effect of a nitroplasticizer (BDNPA/F) on cookoff of a plastic bonded explosive (PBX 9501)

Combustion and Flame

Hobbs, Michael L.; Kaneshige, Michael J.; Erikson, William W.

We have used a modified version of the Sandia Instrumented Thermal Ignition (SITI) experiment to develop a pressure-dependent, five-step ignition model for a plastic bonded explosive (PBX 9501) consisting of 95 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine (HMX), 2.5 wt% Estane® 5703 (a polyurethane thermoplastic), and 2.5 wt% of a nitroplasticizer (NP): BDNPA/F, a 50/50 wt% eutectic mixture bis(2,2-dinitropropyl)-acetal (BDNPA) and bis(2,2-dinitropropyl)-formal (BDNPF). The five steps include desorption of water, decomposition of the NP to form NO2, reaction of the NO2 with Estane® and HMX, and decomposition of HMX. The model was fit using our experiments and successfully validated with experiments from five other laboratories with scales ranging from about 2 g to more than 2.5 kg of PBX. Our experimental variables included density, confinement, free gas volume, and temperature. We measured internal temperatures, confinement pressure, and ignition time. In some of our experiments, we used a borescope to visually observe the decomposing PBX. Our observations included the endothermic β–δ phase change of the HMX, a small exothermic temperature excursion in low-density unconfined experiments, and runaway ignition. We hypothesize that the temperature excursion in these low density experiments was associated with the NP decomposing exothermically within the PBX sample. This reactant-limited temperature excursion was not observed with our thermocouples in the high-density experiments. For these experiments, we believe the binder diffused to the edges of our high density samples and decomposed next to the highly conductive wall as confirmed by our borescope images.

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TYPE Journal Article YEAR 2016
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Application of the coincidence counting technique to DD neutron spectrometry data at the NIF, OMEGA, and Z

Review of Scientific Instruments

Jones, Brent M.; Lahmann, B.; Milanese, L.M.; Han, W.; Gatu Johnson, M.; Seguin, F.H.; Frenje, J.A.; Petrasso, R.D.; Hahn, K.D.

A compact neutron spectrometer, based on a CH foil for the production of recoil protons and CR-39 detection, is being developed for the measurements of the DD-neutron spectrum at the NIF, OMEGA, and Z facilities. As a CR-39 detector will be used in the spectrometer, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). To reject the background to the required level for measurements of the down-scattered and primary DD-neutron components in the spectrum, the Coincidence Counting Technique (CCT) must be applied to the data. Using a piece of CR-39 exposed to 2.5-MeV protons at the MIT HEDP accelerator facility and DD-neutrons at Z, a significant improvement of a DD-neutron signal-to-background level has been demonstrated for the first time using the CCT. These results are in excellent agreement with previous work applied to DT neutrons.

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TYPE Journal Article YEAR 2016
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Photovoltaic Frequency-Watt Curve Design for Frequency Regulation and Fast Contingency Reserves

IEEE Journal of Photovoltaics

Johnson, Jay

When renewable energy resources are installed in electricity grids, they typically increase generation variability and displace thermal generator control action and inertia. Grid operators combat these emerging challenges with advanced distributed energy resource (DER) functions to support frequency and provide voltage regulation and protection mechanisms. This paper focuses on providing frequency reserves using autonomous IEC TR 61850-90-7 pointwise frequency-watt (FW) functions that adjust DER active power as a function of measured grid frequency. The importance of incorporating FW functions into a fleet of photovoltaic (PV) systems is demonstrated in simulation. Effects of FW curve design, including curtailment, deadband, and droop, were analyzed against performance metrics using Latin hypercube sampling for 20%, 70%, and 120% PV penetration scenarios on the Hawaiian island of Lanai. Finally, to understand the financial implications of FW functions to utilities, a performance function was defined based on monetary costs attributable to curtailed PV production, load shedding, and generator wear. An optimization wrapper was then created to find the best FW function curve for each penetration level. It was found that in all cases, the utility would save money by implementing appropriate FW functions.

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TYPE Journal Article YEAR 2016
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On the consistency between nearest-neighbor peridynamic discretizations and discretized classical elasticity models

Computer Methods in Applied Mechanics and Engineering

Seleson, Pablo; Du, Qiang; Parks, Michael L.

The peridynamic theory of solid mechanics is a nonlocal reformulation of the classical continuum mechanics theory. At the continuum level, it has been demonstrated that classical (local) elasticity is a special case of peridynamics. Such a connection between these theories has not been extensively explored at the discrete level. This paper investigates the consistency between nearest-neighbor discretizations of linear elastic peridynamic models and finite difference discretizations of the Navier–Cauchy equation of classical elasticity. Although nearest-neighbor discretizations in peridynamics have been numerically observed to present grid-dependent crack paths or spurious microcracks, this paper focuses on a different, analytical aspect of such discretizations. We demonstrate that, even in the absence of cracks, such discretizations may be problematic unless a proper selection of weights is used. Specifically, we demonstrate that using the standard meshfree approach in peridynamics, nearest-neighbor discretizations do not reduce, in general, to discretizations of corresponding classical models. We study nodal-based quadratures for the discretization of peridynamic models, and we derive quadrature weights that result in consistency between nearest-neighbor discretizations of peridynamic models and discretized classical models. The quadrature weights that lead to such consistency are, however, model-/discretization-dependent. We motivate the choice of those quadrature weights through a quadratic approximation of displacement fields. The stability of nearest-neighbor peridynamic schemes is demonstrated through a Fourier mode analysis. Finally, an approach based on a normalization of peridynamic constitutive constants at the discrete level is explored. This approach results in the desired consistency for one-dimensional models, but does not work in higher dimensions. The results of the work presented in this paper suggest that even though nearest-neighbor discretizations should be avoided in peridynamic simulations involving cracks, such discretizations are viable, for example for verification or validation purposes, in problems characterized by smooth deformations. Moreover, we demonstrate that better quadrature rules in peridynamics can be obtained based on the functional form of solutions.

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TYPE Journal Article YEAR 2016
DOIOSTIScopus

Method for measuring the unbinding energy of strongly-bound membrane-associated proteins

Biochimica et Biophysica Acta - Biomembranes

Kent, Michael S.; La Bauve, Elisa; Vernon, Briana C.; Ye, Dongmei Y.; Rogers, David M.; Mayes, Cathryn M.; Carson, Bryan; Rempe, Susan B.; Zheng, Aihua; Kielian, Margaret; Shreve, Andrew P.

We describe a new method to measure the activation energy for unbinding (enthalpy ΔH*u and free energy ΔG*u) of a strongly-bound membrane-associated protein from a lipid membrane. It is based on measuring the rate of release of a liposome-bound protein during centrifugation on a sucrose gradient as a function of time and temperature. The method is used to determine ΔH*u and ΔG*u for the soluble dengue virus envelope protein (sE) strongly bound to 80:20 POPC:POPG liposomes at pH 5.5. ΔH*u is determined from the Arrhenius equation whereas ΔG*u is determined by fitting the data to a model based on mean first passage time for escape from a potential well. The binding free energy ΔGb of sE was also measured at the same pH for the initial, predominantly reversible, phase of binding to a 70:30 PC:PG lipid bilayer. The unbinding free energy (20 ± 3 kcal/mol, 20% PG) was found to be roughly three times the binding energy per monomer, (7.8 ± 0.3 kcal/mol for 30% PG, or est. 7.0 kcal/mol for 20% PG). This is consistent with data showing that free sE is a monomer at pH 5.5, but assembles into trimers after associating with membranes. This new method to determine unbinding energies should be useful to understand better the complex interactions of integral monotopic proteins and strongly-bound peripheral membrane proteins with lipid membranes.

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TYPE Journal Article YEAR 2016
DOIDOIOSTIOSTIScopusScopus

Collective non-perturbative coupling of 2D electrons with high-quality-factor terahertz cavity photons

Nature Physics

Qi, Z.; Lou, Minhan; Li, Xinwei; Reno, John L.; Pan, Wei; Watson, John D.; Manfra, Michael J.; Kono, Junichiro

The collective interaction of electrons with light in a high-quality-factor cavity is expected to reveal new quantum phenomena and find applications in quantum-enabled technologies. However, combining a long electronic coherence time, a large dipole moment, and a high quality-factor has proved difficult. Here, we achieved these conditions simultaneously in a two-dimensional electron gas in a high-quality-factor terahertz cavity in a magnetic field. The vacuum Rabi splitting of cyclotron resonance exhibited a square-root dependence on the electron density, evidencing collective interaction. This splitting extended even where the detuning is larger than the resonance frequency. Furthermore, we observed a peak shift due to the normally negligible diamagnetic term in the Hamiltonian. Finally, the high-quality-factor cavity suppressed superradiant cyclotron resonance decay, revealing a narrow intrinsic linewidth of 5.6 GHz. High-quality-factor terahertz cavities will enable new experiments bridging the traditional disciplines of condensed-matter physics and cavity-based quantum optics.

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TYPE Journal Article YEAR 2016
DOIOSTIScopus

Unified Nusselt- and Sherwood-number correlations in axisymmetric finite-gap stagnation and rotating-disk flows

International Journal of Heat and Mass Transfer

Coltrin, Michael E.; Kee, Robert J.

This paper develops a unified analysis of stagnation flow heat and mass transport, considering both semi-infinite domains and finite gaps, with and without rotation of the stagnation surface. An important objective is to derive Nusselt- and Sherwood-number correlations that represent heat and mass transport at the stagnation surface. The approach is based on computationally solving the governing conservation equations in similarity form as a boundary-value problem. The formulation considers ideal gases and incompressible fluids. The correlated results depend on fluid properties in terms of Prandtl, Schmidt, and Damköhler numbers. Heterogeneous chemistry at the stagnation surface is represented as a single first-order reaction. A composite Reynolds number represents the combination of stagnation flows with and without stagnation-surface rotation.

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TYPE Journal Article YEAR 2016
DOIOSTIScopus

Potential seal bypass and caprock storage produced by deformation-band-to-opening-mode-fracture transition at the reservoir/caprock interface

Geofluids

Raduha, S.; Butler, D.; Mozley, P.S.; Person, M.; Evans, J.; Heath, Jason E.; Dewers, T.A.; Stauffer, P.H.; Gable, C.W.; Kelkar, S.

We examined the potential impact on CO2 transport of zones of deformation bands in reservoir rock that transition to opening-mode fractures within overlying caprock. Sedimentological and petrophysical measurements were collected along an approximately 5 m × 5 m outcrop of the Slick Rock and Earthy Members of the Entrada Sandstone on the eastern flank of the San Rafael Swell, Utah, USA. Measured deformation band permeability (2 mD) within the reservoir facies is about three orders of magnitude lower than the host sandstone. Average permeability of the caprock facies (0.0005 mD) is about seven orders of magnitude lower than the host sandstone. Aperture-based permeability estimates of the opening-mode caprock fractures are high (3.3 × 107 mD). High-resolution CO2–H2O transport models incorporate these permeability data at the millimeter scale. We varied fault properties at the reservoir/caprock interface between open fractures and deformation bands as part of a sensitivity study. Numerical modeling results suggest that zones of deformation bands within the reservoir strongly compartmentalize reservoir pressures largely blocking lateral, cross-fault flow of supercritical CO2. Significant vertical CO2 transport into the caprock occurred in some scenarios along opening-mode fractures. The magnitude of this vertical CO2 transport depends on the small-scale geometry of the contact between the opening-mode fracture and the zone of deformation bands, as well as the degree to which fractures penetrate caprock. The presence of relatively permeable units within the caprock allows storage of significant volumes of CO2, particularly when the fracture network does not extend all the way through the caprock.

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TYPE Journal Article YEAR 2016
DOIOSTIScopusDOIOSTIScopus

Using Muons to Image the Subsurface

Bonal, Nedra; Cashion, Avery T.; Cieslewski, Grzegorz; Dorsey, Daniel J.; Foris, Adam J.; Miller, Timothy J.; Roberts, Barry L.; Su, Jiann-Cherng; Dreesen, Wendi; Green, J.A.; Schwellenbach, David

Muons are subatomic particles that can penetrate the earth’s crust several kilometers and may be useful for subsurface characterization. The absorption rate of muons depends on the density of the materials through which they pass. Muons are more sensitive to density variation than other phenomena, including gravity, making them beneficial for subsurface investigation. Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and the detector, much like a CAT scan. Currently, muon tomography can resolve features to the sub-meter scale.

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TYPE SAND Report YEAR 2016
DOIOSTI

3AMP Interim Characteristics and Development Report

Partridge, Michael E.

The 3AMP Interim penetrator instrumentation data recorder replaces the original 3AMP design that became unavailable due to sunset electronic components. The revised design meets or exceeds the capabilities of the original design. The 3AMP Interim records six analog channels at 75k samples per second, with a recording time of 581 milliseconds. The 3AMP was designed for sub-scale penetrator tests, but found application in a variety of testing where an extremely robust acceleration recorder was required. This report describes the 3AMP Interim design including schematics and firmware, plus the user interface software used to configure the device as well as extract data post-test.

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TYPE SAND Report YEAR 2016
DOIOSTI

Coarse-Grained Reactive Molecular Dynamics Simulations of Heterogeneities in Shocked Energetic Materials (LDRD Final Report)

Thompson, Aidan P.

This report summarizes the result of LDRD project 16-0161, titled "Coarse-Grained Re- active Molecular Dynamics Simulations of Heterogeneities in Shocked Energetic Materials." The purpose of the project was to develop a coarse-grained reactive molecular dynamics capability in LAMMPS enabling simulations of initiation in energetic materials comparable in accuracy to what is currently possible using large-scale reactive molecular dynamics, but with greatly reduced computational cost. The starting point for this work was the reactive dissipative particle dynamics (DPD) approach, which has been implemented as the new USER-DPD package in LAMMPS by researchers at Army Research Laboratory. Using modified versions of the examples provided with the new package, we examined the computational efficiency of the method, as well as its ability to model energy release in energetic materials. We observed that the Shardlow splitting method provides a great speed and accuracy advantage over conventional velocity Verlet time integration. We observed that the generic model of an energetic material provided with the USER-DPD package exhibited incomplete reaction under constant volume conditions. This was caused by quenching of the internal temperature of the molecules due to a rapid build-up of repulsive interactions between product gas components under constant volume conditions. Under constant pressure conditions, complete reaction was observed, as volume expansion prevented the buildup of strong repulsive interactions. Finally, a more realistic model calibrated to reproduce the equation of state of the RDX molecular crystal was examined. This model exhibited much less quenching of the internal temperature under constant volume conditions and reacted very rapidly under constant pressure conditions.

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TYPE SAND Report YEAR 2016
DOIOSTI

Critical point calculations of BSE and SiO2

Cochrane, Kyle

Included in this memo are the final values for the BSE and SiO2 critical points. VASP 5.3.3 was used to calculate the values in each table. Standard methodology is to continue equilibrating the simulation until the block averaged standard deviation is less than 1%. However, due to the simulation sizes in these simulations, the average standard deviation of the BSE pressure is 5% (ranging between 2% and 7%, which is much higher than the usual under 1% considered acceptable) and the SiO2 pressure is 6% with the lower density error bars being significantly larger than the highest density. The critical point is chosen where the dP/dρ >= 0 for an entire isotherm but is often difficult to distinguish because of the noise along each isotherm. As such, the actual values of the critical points are found by “best guess”. Further computer simulations creating a more pressure values along each isotherm would help but time constraints preclude this. Similarly, the ability to calculate pressures at lower densities that are currently feasible with VASP would also make determination of the critical point easier.

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TYPE Other Report YEAR 2016
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Measures and Metrics Report for Corporate Procedures (Q4 FY2016)

Wright, Emily D.; Deike, Kraig P.; Mccandless-Mcphee, Carrie; Portillos, Stefanie

This quarterly summary report addresses measures and metrics as they pertain to risk, evaluation, and corrective action records in the Assurance Information System (AIS). This quarterly report is the product of a combined effort by the Risk, Assessments, and Take Action procedure subject matter experts (SMEs) to analyze the available data, primarily data from the AIS corporate application. The purpose of this report is to monitor implementation and identify improvement opportunities.

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TYPE Other Report YEAR 2016
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Using and Developing Novel Data Analytics for Digitalized Microstructures. Draft

Castillo, Andrew R.; Mitchell, John A.; Bond, Stephen D.

The primary goal of this work is to develop and implement analytic methods for quantitative analysis of microstructure. These analytic methods are demonstrated on microstructures generated by the Sandia kinAic Monte Carlo code SPPARKS. This report documents progress to that end as well as incremental work towards larger aspirations of making process-structure-property connections for complex processes such as welding and additive manufacturing.

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TYPE SAND Report YEAR 2016
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Modeling Shock-Driven Reaction in Low-Density Non-energetic polymeric materials

Brundage, Aaron; Alexander, Charles S.; Reinhart, William D.

Shock experiments on low density polyurethane foams reveal evidence of reaction at low impact pressures. However, these reaction thresholds are not evident over the low pressures reported for historical Hugoniot data of highly distended polyurethane at densities below 0.1 g/cc. To fill this gap, impact data for PMDI foam with a density of 0.087 g/cc were acquired for model validation. An equation of state (EOS) was developed to predict the shock response of these highly distended materials over the full range of impact conditions representing compaction of the inert material, low-pressure decomposition, and compression of the reaction products. A tabular SESAME EOS of the reaction products was generated using the JCZS database in the TIGER equilibrium code. In particular, the Arrhenius Burn EOS, a two-state model which transitions from an unreacted to a reacted state using Arrhenius kinetics, as implemented in the shock physics code CTH, was modified to include a statistical distribution of states. Hence, a single EOS is presented that predicts the onset to reaction due to shock loading in PMDI-based polyurethane foams. This methodology was also used to predict the anomalous compaction of PMDI foams over published data sets from 0.087 to 0.87 g/cc, and solid Polyurethane at a theoretical maximum density (TMD) of 1.264 g/cc. Likewise, similar modeling techniques were used to predict the performance of SX-358 foam, an RTV-based stress cushion material at a nominal density of 0.41 g/cc, and the matrix material, with properties similar to Sylgard, at 1.1 g/cc. At the start of this study, data were only available at a single impact condition below the threshold for reaction; hence, the decomposition of this material at higher pressures was revealed as a significant finding of this work. The decomposition of SX-358 at higher impact pressures to product species including solid, liquid, and gaseous molecules was estimated with thermochemical equilibrium calculations using TIGER. with thermochemical equilibrium calculations using TIGER. This modeling approach, developed for PMDI foam, was shown to predict gas gun data, acquired as part of this study, up to pressures of 14 GPa. Furthermore, additional phase transitions were predicted in the product species under shock compression. To date, this study is the first known to the authors that demonstrates and successfully predicts the decomposition of these low-density polymer-based foams using a single model applicable to a broad range of impact loading conditions.

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TYPE Other Report YEAR 2016
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Annular Core Research Reactor High Bay Neutron Energy Spectrum Measurements

Kaiser, Krista I.; Martin, Lonnie E.; Mclean, Thomas D.

The Annular Core Research Reactor (ACRR) recently underwent a multi-department effort to characterize the neutron energy leakage spectra in the reactor High Bay for multiple shielding configurations. The ACRR Operations Department identified and obtained a Rotating Neutron Spectrometer (ROSPEC) from Los Alamos National Laboratories (LANL) for obtaining neutron energy spectra. Spectra were obtained in the following facility configurations; Fuel Ringed External Cavity, Version II (FREC-II) decoupled with the standard FREC shield plug installed with the following operational permutations: the 4-inch central cavity (CC) shield plug removed in both a free-field (FF) and 44(3y (Blead-boron (LB-44) bucket neutron modifier configuration, fully shielded CC plug FF condition, neutron radiography collimator aperture settings 250:1, 125:1, and 65:1, FREC-II coupled with both the lightweight (2T1) and standard shield plug configurations. The ROSPEC spectrum results were unfolded, evaluated and weighted using the International Commission on Radiation Protection (ICRP) 103 neutron radiation weighting factors to obtain a ratio amongst the different shielding configurations at the ACRR. Results of the collected spectra confirm that the predominant neutron energy range in the High Bay area is less than or equal to 250 keV.

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TYPE SAND Report YEAR 2016
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Identifying Barriers and Pathways to Success for Renewable Energy Development on American Indian Lands

Energy Policy

Necefer, Len E.; Jones, Thomas E.

American Indian tribes possess lands rich with renewable energy (RE) resources. Tribes have great potential and need to develop these resources, yet face a host of barriers that continue to impede development. Understanding these challenges as well as the pathways that can be taken to overcome them may facilitate more economic development to meet community needs and better position tribes to play a role in securing a low-carbon energy future for the United States. This paper presents the results of an expert elicitation of 24 tribal energy experts from federal, tribal, academic, and private industry backgrounds to identify barriers and opportunities for federally recognized tribes in the lower 48 states. Experts identified a number of unique challenges facing tribes including financing and funding, infrastructure, tribal leadership and staff, state-level influence, and partnerships. Cultural factors were seen only to be of concern with large-scale development. Tribal sovereignty is a significant motivation for RE development and has yet to be fully realized. Cultural considerations are critical to the success of future projects; smaller residential and community-scale projects may be a better fit. Improving partnerships between tribes and the private sector can increase RE deployment and overcome historical distrust. States can have a double-ended influence on projects within tribal lands through taxation.

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TYPE Journal Article YEAR 2016
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