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

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At least 37 records · Page 2

Dry and hot: the hydraulic consequences of a climate change-type drought for Amazonian trees

How plants respond physiologically to leaf warming and low water availability may determine how they will perform under future climate change. In 2015-2016 an unprecedented drought occurred across Amazonia with record-breaking high temperatures and low soil moisture, offering a unique opportunity to evaluate the performances of Amazonian trees to a severe climatic event. We quantified the responses of leaf water potential, sap velocity, whole-tree hydraulic conductance (Kwt), turgor loss and xylem embolism, during and after the 2015-2016 El Niño for five canopy-tree species. Leaf/xylem safety margins (SM), sap velocity and Kwt showed a sharp drop during warm periods. SMs were negatively correlated with vapor pressure deficit but had no significant relationship with soil water storage. Based on our calculations of canopy stomatal and xylem resistances, the decrease in sap velocity and Kwt was due to a combination of xylem cavitation, and stomatal closure. Our results suggest extremely warm droughts greatly amplify the degree of trees’ physiological stress and can lead to mortality. Given the extreme nature of the 2015-2016 El Niño and that temperatures are predicted to increase, this work can serve as a case study of the possible impact climate warming can have on tropical trees.

Fontes, Clarissa G.↗

Consequences of Femtosecond Laser Filament Generation Conditions in Standoff Laser Induced Breakdown Spectroscopy

We investigate the role of femtosecond laser focusing conditions on ablation properties and its implications on analytical merits and standoff detection applications. Femtosecond laser pulses can be used for ablation either by tightly focusing or by using filaments generated during its propagation. We evaluated the persistence of atomic, and molecular emission features as well as time evolution of the fundamental properties (temperature and density) of ablation plumes generated using different methods.

laser ablation (LA)↗

Consequences of CCD imperfections for cosmology determined by weak lensing surveys: from laboratory measurements to cosmological parameter bias

Weak gravitational lensing causes subtle changes in the apparent shapes of galaxies due to the bending of light by the gravity of foreground masses. By measuring the shapes of large numbers of galaxies (millions in recent surveys, up to tens of billions in future surveys) we can infer the parameters that determine cosmology. Imperfections in the detectors used to record images of the sky can introduce changes in the apparent shapes of galaxies, which in turn can bias the inferred cosmological parameters. In this paper we consider the effect of two widely discussed sensor imperfections: tree rings, due to impurity gradients that cause transverse electric fields in the charge-coupled devices (CCDs), and pixel size variation, due to periodic CCD fabrication errors. These imperfections can be observed when the detectors are subject to uniform illumination (flat-field images). We develop methods to determine the spurious shear and convergence (due to the imperfections) from the flat-field images. We calculate how the spurious shear when added to the lensing shear will bias the determination of cosmological parameters. We apply our methods to candidate sensors of the Large Synoptic Survey Telescope (LSST) as a timely and important example, analyzing flat-field images recorded with LSST prototype CCDs in the laboratory. We find that tree rings and periodic pixel size variation present in the LSST CCDs will introduce negligible bias to cosmological parameters determined from the lensing power spectrum, specifically w, Ω{sub m}, and σ{sub 8}.

79 ASTRONOMY AND ASTROPHYSICS↗

Examining the Effect of Plume Rise on Radiological Consequences of Nuclear Accidents

A nuclear accident could cause release of radioactive material outside containment. This material will eventually disperse into the surrounding environment, and could pose a serious threat to public safety, and environment. Mitigation of radiological consequences of such an accident is highly desirable, and since Fukushima accident, there has been a growing focus on nuclear utilities to develop capabilities for this purpose. Undoubtedly, suppression of radioactive material release and dispersion is the primary mean for mitigating radiological consequences nevertheless alternative methods should also be explored to broaden the spectrum of choices for actual circumstances. As we know that, dispersion of radioactive material and subsequent radiological consequences are affected by plume rise. Plume rise is an important factor in determining ground level contamination since it can increase effective release height appreciably provided that effluent discharge speed and temperature is high enough. Under most circumstances, one can expect reduction in radiological consequences due to lower levels of radiation dose and ground contamination in the presence of adequate plume rise. Nevertheless, the effect of plume rise is usually ignored in radiological consequence studies for the sake of conservatism, and lack of information. However, this particular attribute of plume rise interested us to investigate the effect of plume rise in the scope of consequence mitigation and how this advantage could be utilized during an accident progression to minimize the impact of radioactivity release to the environment. In this work, we examine the effect of plume rise on radiological consequences of a nuclear accident for plume rise contributions much larger ({approx}500 m) than usually achievable in normal circumstances. The effect of plume rise on radiological consequences is quantified in this study as decontamination credit (DCC) achievable corresponding to maximum annual dose. This analysis is performed for a number of release heights and atmospheric conditions. We discuss available results in the scope of radiological consequence mitigation, devising a strategy for utilizing plume rise phenomenon with the help of an external propelling device like a jet engine for radiological consequence management. This study is continuation of our efforts for devising systems and strategies to mitigate consequences of radioactivity release accidents like Fukushima. We have proposed several ideas for suppressing/preventing the dispersion of released radioactive material to the environment using offsite equipment.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Criticality Analysis of a Water Distribution System Considering Both Economic Consequences and Hydraulic Loss Using Modern Portfolio Theory

This study introduces an approach using Modern Portfolio Theory (MPT) to consider hydraulic resilience and economic consequence resilience of a water distribution system (WDS) to identify critical assets. ECLIPS (Economic Consequence Linked to Interruption in Providing Service), a way to represent loss of water provision as economic loss, is used to measure economic consequence following a reduction of WDS functionality. The approach is demonstrated using a hypothetical WDS and tested for pipe breakage and replacement scenarios using EPANET hydraulic simulations. First, the correlation between hydraulic resilience and economic consequence resilience was investigated to assess differences between two resilience measures for identifying pipe’s criticality for replacement. The results confirmed the two resilience measures exhibited differing responses (covariance = 0.2), suggesting that use of both would provide complementary insight. Results of the MPT analysis identified the benefits of balancing hydraulic and economic consequence resilience measures to yield lower risk. This study provides a practical approach to incorporate economic consequence into planning, design, and research applications identifying critical WDS assets.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Drinking Water Consequences Tools. A Literature Review

In support of the goals of Department of Homeland Security’s (DHS) National Protection and Programs Directorate and the Federal Emergency Management Agency, the DHS Office of Science and Technology is seeking to develop and/or modify consequence assessment tools to enable drinking water systems owner/operators to estimate the societal and economic consequences of drinking water disruption due to the threats and hazards. This work will expand the breadth of consequence estimation methods and tools using the best-available data describing water distribution infrastructure, owner/assetlevel economic losses, regional-scale economic activity, and health. In addition, this project will deploy the consequence methodology and capability within a Web-based platform. This report is intended to support DHS effort providing a review literature review of existing assessment tools of water and wastewater systems consequences to disruptions. The review includes tools that assess water systems resilience, vulnerability, and risk. This will help to understand gaps and limitations of these tools in order to plan for the development of the next-generation consequences tool for water and waste water systems disruption.

54 ENVIRONMENTAL SCIENCES↗

Low-Probability High-Consequence (LPHC) Failure Events in Geologic Carbon Sequestration Pipelines and Wells: Framework for LPHC Risk Assessment Incorporating Spatial Variability of Risk

If Carbon dioxide Capture and Storage (CCS) is to be effective in mitigating climate change, it will need to be carried out on a very large scale. This will involve many thousands of miles of dedicated high-pressure pipelines in order to transport many millions of tonnes of CO 2 annually, with the CO 2 delivered to many thousands of wells that will inject the CO 2 underground. The new CCS infrastructure could rival in size the current U.S. upstream natural gas pipeline and well infrastructure. This new infrastructure entails hazards for life, health, animals, the environment, and natural resources. Pipelines are known to rupture due to corrosion, from external forces such as impacts by vehicles or digging equipment, by defects in construction, or from the failure of valves and seals. Similarly, wells are vulnerable to catastrophic failure due to corrosion, cement degradation, or operational mistakes. While most accidents involving pipelines and wells will be minor, there is the inevitable possibility of accidents with very high consequences, especially to public health. The most important consequence of concern is CO 2 release to the environment in concentrations sufficient to cause death by asphyxiation to nearby populations. Such accidents are thought to be very unlikely, but of course they cannot be excluded, even if major engineering effort is devoted (as it will be) to keeping their probability low and their consequences minimized. This project has developed a methodology for analyzing the risks of these rare but high-consequence accidents, using a step-by-step probabilistic methodology. A key difference between risks for pipelines and wells is that the former are spatially distributed along the pipe whereas the latter are confined to the vicinity of the well. Otherwise, the methodology we develop for risk assessment of pipeline and well failures is similar and provides an analysis both of the annual probabilities of accident sequences of concern and of their consequences, and crucially the methodology provides insights into what measures might be taken to mitigate those accident sequences identified as of concern. Mitigating strategies could address reducing the likelihood of an accident sequence of concern, or reducing the consequences, or some combination. The methodology elucidates both local and integrated risks along the pipeline or at the well providing information useful to decision makers at various levels including local (e.g., property owners and town councils), regional (e.g., county and state representatives), and national levels (federal regulators and corporate proponents).

54 ENVIRONMENTAL SCIENCES↗

Chemical Consequence Analysis and Atmospheric Dispersion Coefficients under DOE-STD-3009-2014 Nuclear Safety Analysis

During preparation of non-reactor nuclear facility documented safety analyses (DSAs), chemical consequence analysis is an important contributor to correctly identifying and classifying nuclear safety controls. The Department of Energy (DOE) recently-issued DOE-STD-3009-2014, which increases the focus on chemical hazards within non-reactor nuclear facilities, and imposes additional requirements. Chemical consequence analysis can be significantly more complicated than radiological consequence analysis. Specifically, atmospheric dispersion factors used in chemical consequence analysis must consider several additional factors, such as the energy of the release, buoyancy, and initial chemical concentration. This paper describes the overall requirements of chemical consequence analysis under DOE-STD- 3009-2014, and provides specific guidance for determining an applicable atmospheric dispersion coefficient for use in chemical consequence analysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Consequence analyses of sabotage-induced radiological releases in high-temperature helium-cooled prismatic microreactors

Here, this study analyzes the radiological dose consequences of sabotage-induced accidents at three high-temperature helium-cooled prismatic microreactors (HTPMs) with thermal power ratings of 1, 10, and 50 MWt. Each HTPM employs uranium oxycarbide tristructural isotropic fuel enriched to 19.75 wt% high-assay low-enriched uranium. Simulations were conducted to estimate reactor core inventory at the point of fuel discharge––when the effective multiplication factor reduced to less than 1––representing peak radionuclide inventory. Postulated sabotage scenarios leading to reactor shutdown were analyzed at two intervals: immediately post-shutdown (0 h) and 3 days after shutdown using the SCALE code for radionuclide inventories and the RASCAL tool for dose consequences. Results show that although HTPMs benefit from inherent safety features and robust fuel design, radiological consequences scale with reactor power because of increased source term inventories. Smaller microreactors exhibited proportionally lower dose consequences. To support the economic and regulatory feasibility of microreactor deployment, this study emphasizes the value of a risk-informed, performance-based approach, as supported by regulations like 10 CFR Parts 100 and 53 in the United States. Microreactor developers should perform site-specific assessments of potential sabotage or low-probability, high-consequence events, especially when considering minimal on-site or full off-site emergency response.

Consequence↗

Addressing Consequence within Operational Risk (O.T. Gagnon III) 9-18-2024

Addressing Consequence within Operational Risk: Why threats and security are just not that important! When dealing with cyber or physical risk within any critical infrastructure (CI) environment, don’t concern yourself with vulnerabilities and threats, at least not at first! Also, don’t be overly fixated on “securing the systems” within the organization. The endeavor of tackling operational risk focused on consequences in any critical infrastructure environment to include the complex Aviation ecosystem is challenging even for the most resourced entity but can be advanced though a simplified approach: identifying, binning, and prioritizing the infrastructure environment. While no two entities within a single element of the 16 critical infrastructure sectors are exactly alike when it comes to risk, there is a basic process to move toward a greater understanding of operational risk through becoming more informed about the infrastructure environment in which the entity exists. The process starts with bringing internal and external stakeholders and subject matter experts together to analyze key areas such as Information Technology (IT) and Operational Technology (OT) components and points of convergence, analyzing internal and external cyber and physical dependencies, accounting for explosive growth in devices and wireless technology, and leveraging the contributions of people inside and outside the operational environment. Attaining a common understanding of the infrastructure environment as part of addressing consequences within operational risk is not easy to do or resource light, but the process outlined provides the framework to further any entity’s efforts in this space. When it comes to cyber risks, before an organization can consider vulnerabilities within and threats to its operations, it must first have a solid understanding of the consequences existing inside its infrastructure environment. Idaho National Lab’s Consequence-Driven, Cyber-Informed Engineering is offered as an example of this approach to effective and efficient cyber risk mitigation.

99 GENERAL AND MISCELLANEOUS↗

Economic Consequence Analysis of Disasters: The ECAT Software Tool

This study develops a methodology for rapidly obtaining approximate estimates of the economic consequences from numerous natural, man-made and technological threats. This software tool is intended for use by various decision makers and analysts to obtain estimates rapidly. It is programmed in Excel and Visual Basic for Applications (VBA) to facilitate its use. This tool is called E-CAT (Economic Consequence Analysis Tool) and accounts for the cumulative direct and indirect impacts (including resilience and behavioral factors that significantly affect base estimates) on the U.S. economy. E-CAT is intended to be a major step toward advancing the current state of economic consequence analysis (ECA) and also contributing to and developing interest in further research into complex but rapid turnaround approaches. The essence of the methodology involves running numerous simulations in a computable general equilibrium (CGE) model for each threat, yielding synthetic data for the estimation of a single regression equation based on the identification of key explanatory variables (threat characteristics and background conditions). This transforms the results of a complex model, which is beyond the reach of most users, into a "reduced form" model that is readily comprehensible. Functionality has been built into E-CAT so that its users can switch various consequence categories on and off in order to create customized profiles of economic consequences of numerous risk events. E-CAT incorporates uncertainty on both the input and output side in the course of the analysis.

Environmental Economics↗

Criticality Consequence Analysis Roadmap for Spent Nuclear Fuel Canister in a Repository

This report discusses an initial criticality consequence analysis approach of commercial spent fuel canisters in a repository that will be developed to support a performance assessment (PA) of a repository with criticality events. A repository PA with criticality events may be needed to support direct disposal of currently loaded dual-purpose canisters. The ultimate goal is to develop a criticality consequence analysis model that can interface with any repository PA model. The criticality consequence analysis approach describes multi-physics coupling between neutronics, thermal hydraulics, and mechanics analysis codes. This report also discusses the sensitivity and uncertainty analysis approach for quantifying conservatism in the criticality consequence outcomes, as well as a defensible multi-physics validation approach to support any future licensing effort. This criticality consequence analysis approach will be refined in the future to support specific regulatory frameworks for a specific repository PA if needed.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Radiological Consequences of Hydrogen Explosions in Vessels and Piping at the WTP

Hydrogen (along with other gases) is generated in process vessels and other components at the Hanford Waste Treatment and Immobilization Plant (WTP) due to the radiolysis of water and to the radiolysis and thermolysis of organics in WTP radioactive process wastes. In the absence of controls, the hydrogen may accumulate until a flammable or explosive concentration is reached. Once a buildup has occurred, ignition of the hydrogen causes an explosion that creates radioactive aerosols that could escape the confinement boundary and be released to the environment. Such a release could cause significant radiological exposures to a public receptor at the site boundary and to a co-located worker (CLW/) in the yard areas outside the physical facilities. Hydrogen explosion events therefore require evaluation as to the potential magnitude of their consequences. The WTP methodology for the evaluation of the potential radiological consequences due to hydrogen explosions in vessels and piping is a conservative approach that is defensible from a regulatory standpoint yet only results in the need for Safety controls for the most highly radioactive process vessels (generally those containing waste with significant quantities of solids). For WTP vessels with waste not containing significant quantities of solids, radiological dose consequences are sufficiently low such that neither Safety Class controls for the public receptor nor Safety Significant controls for the CLW are required. Similarly, the dose consequences for hydrogen explosions in piping and ancillary vessels are all very low to both receptors, again indicating that no Safety Class or Safety Significant controls are required. The WTP vessel and piping hydrogen explosion calculations are dependent on vessel and pipe sizes, hydrogen generation rates, operational requirements, and waste stream properties such as solids content, radioisotope concentration, and slurry density. Consequently, the WTP-specific results discussed above cannot be extrapolated directly to other facilities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Consequence-driven cyber-informed engineering (CCE)

The Idaho National Lab (INL) is leading a high-impact, national security-level initiative to reprioritize the way the nation looks at high-consequence risk within the industrial control systems (ICS) environment of the country’s most critical infrastructure and other national assets. The Consequence-driven Cyber-informed Engineering (CCE) effort provides both private and public organizations with the steps required to examine their own environments for high-impact events/risks; identify implementation of key devices and components that facilitate that risk; illuminate specific, plausible cyber attack paths to manipulate these devices; and develop concrete mitigations, protections, and tripwires to address the high-consequence risk. The ultimate goal of the CCE effort is to help organizations take the steps necessary to thwart cyber attacks from even top-tier, highly resourced adversaries that would result in a catastrophic physical effect. CCE participants are encouraged to work collaboratively with each other and with key U.S. Government (USG) contributors to establish a coalition, maximizing the positive effect of lessons-learned and further contributing to the protection of critical infrastructure and other national assets.

97 MATHEMATICS AND COMPUTING↗

Preventive Rad/Nuc Detection Equipment Categorization for Consequence Management

The overall objective of this project is to research, evaluate, and test first responder preventive radiological/nuclear detection equipment (PRND) to provide state and local agencies with guidance on how to best use this equipment for response after a radiological/nuclear release or detonation. While the equipment being tested in this effort has been specifically designed for detection and interdiction operations, the fleet of PRND equipment can help fill critical needs for radiological instrumentation should a consequence management response take place. This effort will provide scientific guidance on the best way to deploy and operate this class of equipment for consequence management missions. With the support of the US Department of Homeland Security’s (DHS) Domestic Nuclear Detection Office (DNDO), PRND equipment has been placed into service at federal, state, and local agencies throughout the nation. If the equipment capability and limitations are taken into account, this large inventory can be repurposed to support the emergency response in the aftermath of a radiological of nuclear event. This report evaluates PRND equipment to define key categories of equipment and the types of missions they can be used for. This is important because there are over 100 different types of PRND equipment, often with significantly different capabilities with respect to the consequence management mission. The current DNDO draft NIMS PRND equipment types were used as a foundation and expanded, when necessary, to address key characteristics important for the consequence mission. Table 1 provides a summary of the PRND instrument categories developed for this effort. Also included on the table are some common response mission detection equipment categories that will be used for capability comparisons.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗