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Insights on Fukushima Damage Progression based on PCV Inspections and Implications for Decommissioning Data Collection and Code Model Refinement [Slides]

Andrews, Nathan C.; Gauntt, Randall O.

Outline points are: Review what is known from experiments and how codes are modeling phenomena; Materials interactions are very important and key interactions will be identified and discussed; Chronology of damage progression roughly follows in order of increasing melting/liquefaction temperatures; Examine a plausible sequence to explain robotic visual examinations; Highlight MELCOR modeling observations; Highlight potential decommissioning phase data collection needs; and, Knowledge advance is iterative process of reconciling observations with code predictions, improving code models, and comparing to emerging new observations.

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TYPE Other Report YEAR 2018
DOIOSTI

Implementation of a Grid Connected Battery-Inverter Fleet Model

Rosewater, David; Gonzalez, Sigifredo

Batteries are designed to store electrical energy. The increasing variation in time value of energy has driven the use of batteries as controllable distributed energy resources (DER). This is enabled though low-cost power electronic inverters that are able to precisely control charge and discharge. This paper describes the software implementation of an open-source battery inverter fleet models in python. The Sandia BatterylnverterFleet class model can be used by scientists, researchers, and engineers to perform simulations of one or more fleets of similar battery-inverter systems connected to the grid. The program tracks the state- of-charge of the simulated batteries and ensures that they stay within their limits while responding to separately generated service requests to charge or discharge. This can be used to analyze control and coordination, placement and sizing, and many other problems associated with the integration of batteries on the power grid. The development of these models along with their python implementation was funded by the Grid Modernization Laboratory Consortium (GMLC) project 1.4.2. Definitions, Standards and Test Procedures for Grid Services from Devices.

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TYPE SAND Report YEAR 2018
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Survey of DAKOTA's V&V Capabilities in the Simulation of Residual Stresses in a Simple Composite Structure

Nelson, Stacy M.; Hanson, Alexander A.

Process-induced residual stresses occur in composite structures composed of dissimilar materials. As these residual stresses can result in fracture, their consideration when designing composite parts is necessary. However, the experimental determination of residual stresses in prototype parts can be time and cost prohibitive. Alternatively, it is possible for computational tools to predict potential residual stresses. Therefore, a process modeling methodology was developed and implemented into Sandia National Laboratories' SIERRA/SolidMechanics code. This method can be used to predict the process-induced stresses in any composite structure, regardless of material composition or geometric complexity. However, to develop confidence in these predictions, they must be rigorously validated. Specifically, sensitivity studies should be completed to define which model parameters are critical to the residual stress predictions. Then, the uncertainty associated with those critical parameters should be quantified and processed through the model to develop stress-state predictions encompassing the most important sources of physical variability. Numerous sensitivity analysis and uncertainty quantification methods exist, each offering specific strengths and weaknesses. Therefore, the objective of this study is to compare the performance of several accepted sensitivity analysis and uncertainty quantification methods during the manufacturing process simulation of a composite structure. The examined methods include simple sampling techniques as well as more sophisticated surrogate approaches. The computational costs are assessed for each of the examined methods, and the results of the study indicate that the surrogate approaches are the most computationally efficient validation methods and are ideal for future residual stress investigations.

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TYPE SAND Report YEAR 2018
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Discharge Permit-1845 Quarterly Status Report October 2018

Li, Jun

Trichloroethene (TCE) and nitrate have been identified as constituents of concern in groundwater at the Sandia National Laboratories, New Mexico (SNL/NM) Technical Area (TA)-V Groundwater (TAVG) Area of Concern (AOC) based on detections above the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) in samples collected from monitoring wells. The EPA MCLs and the State of New Mexico drinking water standards for TCE and nitrate are 5 micrograms per liter and 10 milligrams per liter (as nitrogen), respectively. A phased Treatability Study/Interim Measure (TS/IM) of in-situ bioremediation (ISB) is being implemented to evaluate the effectiveness of ISB as a potential technology to treat the groundwater contamination at the TAVG AOC (New Mexico Environment Department [NMED] April 2016). The NMED Hazardous Waste Bureau (HWB) approved the Revised Treatability Study Work Plan (TSWP) (SNL/NM March 2016) in May 2016 (NMED May 2016). The SNL/NM Environmental Restoration Operations personnel are responsible for implementing the TS/IM of ISB at TAVG AOC in accordance with the Revised TSWP. Per the Revised TSWP, up to three injection wells (TAV-INJ1, TAV-INJ2, and TAV-INJ3) would be installed at TA-V in the vicinity of the highest contaminant concentrations detected in groundwater at monitoring wells LWDS-MW1, TAV-MW6, and TAV-MW10. The injection wells would be used to gravity-inject substrate solution and biodegradation bacteria to groundwater. The substrate solution consists of an inert tracer as well as essential food and nutrients for biostimulation. The substrate solution would be prepared in aboveground tanks. The TS/IM would be conducted in two phases: Phase I includes a pilot test followed by full-scale injection at the first injection well (TAV-INJ1); Phase II includes full-scale injections at the second and third injection wells (TAV-INJ2 and TAV-INJ3). The NMED Ground Water Quality Bureau (GWQB) requires a groundwater Discharge Permit (DP) for the operation of injection wells. NMED GWQB issued the DP-1845 to the U.S. Department of Energy/National Nuclear Security Administration (DOE/NNSA) for the SNL/NM TA-V Treatability Study injection wells on May 26, 2017 (NMED May 2017). The DP-1845 term started on May 30, 2017 and ends on May 30, 2022. Attachment A provides a copy of DP-1845. This quarterly report provides responses to DP-1845 Operating Conditions Terms and Conditions #3 through #8 and Monitoring and Reporting Terms and Conditions #10 through #17 for the April 1 to June 30, 2018 reporting period. The other Terms and Conditions are NMED statements of fact and do not require a response.

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TYPE Other Report YEAR 2018
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Comparing Binary-Swap Algorithms for Odd Factors of Processes

2018 IEEE 8th Symposium on Large Data Analysis and Visualization, LDAV 2018

Moreland, Kenneth D.

A key component of most large-scale rendering systems is a parallel image compositing algorithm, and the most commonly used compositing algorithms are binary swap and its variants. Although shown to be very efficient, one of the classic limitations of binary swap is that it only works on a number of processes that is a perfect power of 2. Multiple variations of binary swap have been independently introduced to overcome this limitation and handle process counts that have factors that are not 2. To date, few of these approaches have been directly compared against each other, making it unclear which approach is best. This paper presents a fresh implementation of each of these methods using a common software framework to make them directly comparable. These methods to run binary swap with odd factors are directly compared. The results show that some simple compositing approaches work as well or better than more complex algorithms that are more difficult to implement.

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TYPE Conference Poster YEAR 2018
DOIOSTIScopus

Development of Elastic Recoil Detection Technique for Quantifying Light Isotope Concentrations in Irradiated TPBAR Materials

Doyle, B.L.; Foulk, James W.; Hattar, Khalid M.; Muntifering, Brittany R.

The National Nuclear Security Administration's Tritium Sustainment Program is responsible for the design, development, demonstration, testing, analysis, and characterization of tritium-producing burnable absorber rods (TPBARs) and their components, in addition to producing tritium for the nation's strategic stockpile. The FY18 call for proposals included the specific basic science research topic, "Demonstration and evaluation of advanced characterization methods, particularly for quantifying the concentration of light isotopes (1H, 2H, and 4He, 6Li, and 7Li) in metal or ceramic matrices". A project IWO-389859 was awarded to the Ion Beam Lab (IBL) at Sandia-NM in FY18. This reports the success we had in developing and demonstrating such a method: 42 MeV Si+ 7 from the IBL' s Tandem was used to recoil these light isotopes into special detectors that separated all these isotopes by simultaneously measuring the energy and stopping power of these reoils. This technique, called Heavy Ion - Elastic Recoil Detection or HI-ERD, accurately measured the enriched 6 Li/Li-total of 0.246 +- 0.016, compared to the known value of 0.239. The isotopes 1H, 2H, 4He, 6Li and 7Li were also measured. (page intentionally left blank)

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TYPE SAND Report YEAR 2018
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Supporting the Nation's Electric Interconnections through Integration of Water into their Long-Term Transmission Planning

Tidwell, Vincent C.; Macknick, Jordan; Voisin, Nathalie; Kuiper, Jim

Water is a critical resource in the production of electric power. The purpose of this plan is to extend support to the nation's three electric interconnections toward integrating water issues into their long-range transmission planning. This continued support is at the request of the interconnections. The proposed program leverages prior support as well as that of other similarly focused efforts funded across the Department of Energy (DOE). The effort will utilize a project team lead by Sandia National Laboratories and supported by Argonne National Laboratory, National Renewable Energy Laboratory, and Pacific Northwest National Laboratory. The activities recorded here are meant to provide a menu of potential projects that could be implemented as available resources permit.

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TYPE Other Report YEAR 2018
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Review of Authentication Strategies and Trends for Distributed Energy Resources (DERs)

Lai, Christine F.; Cordeiro, Patricia G.

In this study we review literature on machine to machine (M2M) authentication and encryption pertaining to communication with grid-attached power inverters. We regard security recommendations from NIST, constrained device recommendations from CoAP, as well as influences from the existing markets. We will not focus on passwordless or multifactor schemes of user authentication, the handover/roaming authentication of mobile systems, or the group authentication of WiMAX/LTE communications. The de-facto standards for authentication and encryption are certificate-based public key cryptography and AES, respectively. While certificate-based public key cryptography is widely adopted, certificate management is seen as an Achilles heel of public key infrastructure (PKI). State of the art authentication system research includes work on certificateless authentication; however, much work in the areas of privacy preservation, efficient or lightweight systems continue to be based in public key methods. We will see efforts such as bilinear pairing, aggregate message authentication codes, one-time signatures, and Merkle trees surface and resurface with improved authentication approaches. Though research continues to produce new encryption schemes, AES prevails as a viable choice, as it can be implemented across a variety of resource constrained devices. Other lightweight encryption algorithms often employ the same fundamental addition-rotation-xor operations as AES while achieving higher efficiency, but at steep tradeoffs to security. Despite mathematical proofs of the security of cryptographic algorithms, in practice the greatest weaknesses continue to be incurred during implementation. Security researchers will find edge cases and bugs that allow unintentional behavior. In the following sections, accepted methodologies of authentication and encryption are discussed. Due diligence for securing M2M communications requires consideration during planning, design, implementation and product lifetime, as opposed to a set-it and forget-it policy. Best practices can be gleaned from published successes and failures, with no single end-all, be-all detailed solution.

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TYPE Other Report YEAR 2018
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ER Consolidated Quarterly Report: January-March 2018

Cochran, John R.

This Sandia National Laboratories, New Mexico Environmental Restoration Operations (ER) Consolidated Quarterly Report (ER Quarterly Report) fulfills all quarterly reporting requirements set forth in the Compliance Order on Consent. Table 1-2 lists the 12 sites in the corrective action process. This ER Quarterly Report presents activities and data as follows: SECTION I: Environmental Restoration Operations Consolidated Quarterly Report, April — June 2018. SECTION II: Perchlorate Screening Quarterly Groundwater Monitoring Report, April — June 2018. SECTION III: Technical Area (TA)-V In-Situ Bioremediation Treatability Study Pilot Test Results.

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TYPE Other Report YEAR 2018
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Building 1090 Modifications Lessons Learned

Allen, Mark B.

The purpose of this document is to capture and disseminate lessons learned from the Sandia National Laboratories (SNL) Building 1090 modification project that took place from 2013 to 2018. The following sections summarize the drivers, issues encountered and lessons learned at each phase in the project.

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TYPE Other Report YEAR 2018
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Modelling Charged Defects in Non-Cubic Semiconductors for Radiation Effects Studies in Next Generation Materials

Schultz, Peter A.

This final report summarizes the results of the Laboratory Directed Research and Development (LDRD) Project Number 212587 entitled "Modeling Charged Defects in Non-Cubic Semiconductors for Radiation Effects Studies in Next Generation Electronic Materials" . The goal of this project was to extend a predictive capability for modeling defect level energies using first principle density functional theory methods (e.g., for radiation effects assessments) to semiconductors with non-cubic crystal structures. Computational methods that proved accurate for predicting defect levels in standard cubic semiconductors, were found to have shortcomings when applied to the lowered symmetry structures prevalent in next generation electronic materials such as SiC, GaN, and Ga203, stemming from an error in the treatment of the electrostatic boundary conditions. I describe methods to generalized the local moment countercharge (LMCC) scheme to position a charge in bulk supercell calculations of charged defects, circumventing the problem of measuring a dipole in a periodically replicated bulk calculation.

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TYPE SAND Report YEAR 2018
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Advances in Geologic Disposal Safety Assessment and an Unsaturated Alluvium Reference Case

Mariner, Paul; Stein, Emily; Cunningham, Leigh; Frederick, Jennifer M.; Hammond, Glenn E.; Lowry, Thomas S.; Basurto, Eduardo

The Spent Fuel and Waste Science and Technology (SFWST) Campaign of the U.S. Depat ment of Energy (DOE) Office of Nuclear Energy (NE), Office of Fuel Cycle Technology (OFCT) is conducting research and development (R&D) on geologic disposal of spent nuclear fuel (SNF) and high level nuclear waste (HLW). Two high priorities for SFWST disposal R&D are design concept development and disposal system modeling (DOE 2011, Table 6). These priorities are directly addressed in the SFWST Geologic Disposal Safety Assessment (GDSA) work package, which is charged with developing a disposal system modeling and analysis capability for evaluating disposal system performance for nuclear waste in geologic media. This report describes specific GDSA activities in fiscal year 2018 (FY 2018) toward the development of GDSA Framework, an enhanced disposal system modeling and analysis capability for geologic disposal of nuclear waste. GDSA Framework employs the PFLOTRAN thermal-hydrologic-chemical multiphysics code (Hammond et al. 2011a; Lichtner and Hammond 2012) and the Dakota uncertainty sampling and propagation code (Adams et al. 2012; Adams et al. 2013). Each code is designed for massivelyparallel processing in a high-performance computing (HPC) environment. Multi-physics representations in PFLOTRAN are used to simulate various coupled processes including heat flow, fluid flow, waste dissolution, radionuclide release, radionuclide decay and ingrowth, precipitation and dissolution of secondary phases, and radionuclide transport through engineered barriers and natural geologic barriers to the biosphere. Dakota is used to generate sets of representative realizations and to analyze parameter sensitivity.

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TYPE Other Report YEAR 2018
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Complexity and Simplicity: Putting Complexity Science in Perspective

Ackermann, Mark R.; Hayden, Nancy K.; Jones, Wendell

As technical systems and social problems in modern society become ever more complex, many organizations are turning to what is commonly termed complexity science to find solutions. The problem many organizations face is that they frequently have no clear idea what they are trying to accomplish, no in-depth understanding of the nature, size and dimension of their problem, and only a limited understanding of what theoretical approaches and off-the-shelf analysis tools exist or are applicable to their particular problem. This paper examines the larger topic of complexity science, providing insight, and helping to place its promises in perspective.

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TYPE SAND Report YEAR 2018
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An Update to the SWiFT V27 Reference Model

Kelley, Christopher L.; White, Jonathan

A revised Sandia V27 reference model is provided for use with the wind turbine analysis code, FAST, incorporating refined parameters based on blade geometry measurements and performance data collected during the 2017 wake steering campaign at the Scaled Wind Farm Technology (SWiFT) site. The chord, twist, and airfoil section shapes were measured at five span locations on the blades of wind turbine WTGb1. The V27 AeroDyn file was updated with values equal to the measured chord and twist. The measured airfoil shapes deviated over the aft half of the chord compared to the original blade model NACA profiles. Differences in trailing edge camber were converted to an equivalent trailing edge flap effect calculated with thin airfoil theory. These mod- ified airfoil polars were updated in the V27 FAST model. The tip-speed-ratio and root bending moment were measured experimentally in the wake steering campaign at SWiFT on wind turbine WTGa1. The torque constant and collective pitch of the model were tuned so that the model output tip-speed-ratio and thrust, root bending moment matched the experiment across all wind speeds in region 2 operation with minimum error.

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TYPE SAND Report YEAR 2018
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Summary Update on the Feasibility of Direct Disposal of SNF in Existing DPCs

Hardin, Ernest

This report is the deliverable M2SF-18SN010305026 FY18 Summary Update on the Feasibility of Direct Disposal of SNF in Existing DPCs. It reports on work done throughout fiscal year (FY) 2018, on work planned at the beginning of that FY, consisting of R&D activities for: 1) injectable fillers that could be used in dual-purpose canisters to prevent postclosure criticality in a geologic repository, and 2) as-loaded DPC data gathering and criticality. The work reported here was performed by Sandia National Laboratories and Oak Ridge National Laboratory. Appropriate attribution to source documents is provided in the text, tables, and figures below. Additional R&D on direct disposal of existing DPCs was planned and funded in mid-FY, and the associated reporting is separate from this milestone. Additional discussion of that new scope and how it implements findings from an independent expert review of the fillers R&D program (Section 10) is provided in the Summary (Section 11).

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TYPE Other Report YEAR 2018
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SIERRA Multimechanics Module: Aria User Manual - Version 4.50

Author, No

Aria is a Galerkin finite element based program for solving coupled-physics problems described by systems of PDEs and is capable of solving nonlinear, implicit, transient and direct-to-steady state problems in two and three dimensions on parallel architectures. The suite of physics currently supported by Aria includes thermal energy transport, species transport, and electrostatics as well as generalized scalar, vector and tensor transport equations. Additionally, Aria includes support for manufacturing process fows via the incompressible Navier-Stokes equations specialized to a low Reynolds number ( Re < 1 ) regime. Enhanced modeling support of manufacturing processing is made possible through use of either arbitrary Lagrangian- Eulerian (ALE) and level set based free and moving boundary tracking in conjunction with quasi-static nonlinear elastic solid mechanics for mesh control. Coupled physics problems are solved in several ways including fully-coupled Newton's method with analytic or numerical sensitivities, fully-coupled Newton- Krylov methods and a loosely-coupled nonlinear iteration about subsets of the system that are solved using combinations of the aforementioned methods. Error estimation, uniform and dynamic h-adaptivity and dynamic load balancing are some of Aria's more advanced capabilities.

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TYPE SAND Report YEAR 2018
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SIERRA Low Mach Module: Fuego User Manual - Version 4.50

Author, No

The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the core architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.

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TYPE SAND Report YEAR 2018
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SIERRA Multimechanics Module: Aria Thermal Theory Manual - Version 4.50

Author, No

This document describes the theoretical foundation of thermal analysis in Sierra Mechanics. The SIERRA Multimechanics Module: Aria, henceforth referred to as Aria for brevity, was developed at Sandia National Laboratories under the ASC program, and approximates linear and nonlinear continuum models of heat transfer. Aria uses the SIERRA Framework, which provides data management services commonly required by computational mechanics software, and facilitates the development of coupled, multi-mechanics applications for massively parallel computers. The mathematical models in Aria are based heavily on those of COYOTE, a well-established thermal analysis program that was also developed at Sandia and its ASC code predecessor, Calore. Aria, Calore and COYOTE share a significant body of numerical methods, which are described in detail by Reddy and Gartling. Throughout this document, the terms software and implementation are synonymous with the Aria thermal-fluid analysis computer program. Whether one uses Aria to perform heat transfer analysis, or in developing a new capability for the Aria application, this document provides the information needed understand the existing numerical algorithm implementations. Justification for the fundamental assumptions of heat transfer, nor derivation of the energy conservation equations are included in this document. For a more thorough theoretical background, one is referred to one of the many available textbooks, e.g. Another reference, which is freely available in downloadable electronic form, is Lienhard and Lienhard.

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TYPE SAND Report YEAR 2018
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SIERRA Low Mach Module: Fuego Theory Manual - Version 4.50

Author, No

The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASC fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the core architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.

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TYPE SAND Report YEAR 2018
DOIOSTI

SIERRA/Aero User Manual - Version 4.50

Author, No

SIERRA/Aero is a compressible fluid dynamics program intended to solve a wide variety compressible fluid flows including transonic and hypersonic problems. This document describes the commands for assembling a fluid model for analysis with this module, henceforth referred to simply as Aero for brevity. Aero is an application developed using the SIERRA Toolkit (STK). The intent of STK is to provide a set of tools for handling common tasks that programmers encounter when developing a code for numerical simulation. For example, components of STK provide field allocation and management, and parallel input/output of field and mesh data. These services also allow the development of coupled mechanics analysis software for a massively parallel computing environment. In the definitions of the commands that follow, the term Real_Max denotes the largest floating point value that can be represented on a given computer. Int_Max is the largest such integer value.

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TYPE SAND Report YEAR 2018
DOIOSTI

Facilities & Infrastructure Five-Year Investment Plan

Billie, Gepetta S.

The Facilities & Infrastructure (F&I) Five-Year Investment Plan (Five-Year Plan) presents a framework to acquire, maintain, modify, and dispose real property assets with indirect and direct-funded investments to sustain and modernize Sandia's F&I portfolio. This plan begins with a description of the principles used to guide decision-making for indirect-funded investments followed by a high—level view of F&I investments planned in the near— and mid—terms to meet emerging F&I needs required to support current and future mission work across Sandia's campuses.

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TYPE Other Report YEAR 2018
DOIOSTI

Water Resource Assessment in the New Mexico Permian Basin

Lowry, Thomas S.; Schuhen, Michael D.; Lofton, Owen; La Jenkins, Tonya N.; Johnson, Patricia B.; Powers, Dennis W.; Bowman, Dale

Advancements in directional drilling and well completion technologies have resulted in an exponential growth in the use of hydraulic fracturing for oil and gas extraction. Within the New Mexico Permian Basin, water demand to complete each hydraulically fractured well is estimated to average 7.3 acre-feet (2.4 million gallons), resulting in an increase to the regional water demand of over 5000 acre-feet per year. This rising demand is creating concern for the regions ability to meet the demand in a manner that fulfills BLM's role of protecting human health and the environment while sustainably meeting the needs of various of water users in the region. This report documents a study that establishes a water-level and chemistry baseline and develops a modeling tool to aid the BLM in understanding the regional water supply dynamics under different management, policy, and growth scenarios and to pre-emptively identify risks to water sustainability.

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TYPE SAND Report YEAR 2018
DOIOSTI

Final Project Report: PV Stakeholder Engagement Initiatives

Stein, Joshua; Lavrova, Olga

The key objectives of this project were to increase meaningful stakeholder engagement in photovoltaic performance modeling and reliability areas. We did this by hosting six workshop over the past three years, giving conference and workshop presentations and contributing to technical standards committees. Our efforts have made positive contributions by increasing the sharing of information and best practices and by creating and sustaining a technical community in PV Performance Modeling. This community has worked together over the past three years and has improved its practice and decreased performance modeling uncertainties.

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TYPE Other Report YEAR 2018
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Final Project Report: Performance Models and Standards for Bifacial PV Module Technologies

Stein, Joshua

This project has three main objectives: (1) to field and collect performance data from bifacial PV systems and share this information with the stakeholder community; (2) to develop and validate bifacial performance models and deployment guides that will allow users to accurately predict and assess the use of bifacial PV as compared with monofacial technologies and (3) to help develop international power rating standards for bifacial PV modules.

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TYPE Other Report YEAR 2018
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Evaluation of Used Fuel Disposition in Clay-Bearing Rock

Jove-Colon, Carlos F.; Payne, Clay; Knight, A.W.; Ho, Tuan A.; Rutqvist, Jonny; Kim, Kunwi; Xu, Hao; Guglielmi, Yves; Birkholzer, Jens; Caporuscio, Florie; Sauer, Kirsten B.; Rock, M.J.; Houser, L.M.; Jerden, James; Gattu, Vineeth K.; Ebert, William

The DOE R&D program under the Spent Fuel Waste Science Technology (SFWST) campaign has made key progress in modeling and experimental approaches towards the characterization of chemical and physical phenomena that could impact the long-term safety assessment of nuclear waste disposition in deep clay/shale/argillaceous rock. Interactional collaboration activities such as heater tests, particularly postmortem sample recovery and analysis, have elucidated important information regarding changes in engineered barrier system (EBS) material exposed to years of thermal loads. Chemical and structural analyses of bentonite material from such tests has been key to the characterization of thermal effects affecting clay composition, sorption behavior, and swelling. These are crucial to evaluating the nature and extent of bentonite barrier sacrificial zones in the EBS during the thermal period. Thermal, hydrologic, and chemical data collected from heater tests and laboratory experiments has been used in the development and validation of THMC simulators to model near-field coupled processes affecting engineered and natural barrier materials, particularly during the thermal period. This information leads to the development of simulation approaches (e.g., continuum vs. discrete) to tackle issues related to flow and transport depending on the nature of the host-rock and EBS design concept. This report describes R&D efforts on disposal in argillaceous geologic media through developments of coupled THMC process models, hydrothermal experiments and characterization of clay/metal barrier material interactions, and spent fuel and canister material degradation. Currently, the THM modeling focus is on heater test experiments in argillite rock and gas migration in bentonite as part of international collaboration activities at underground research laboratories (URLs). In addition, field testing at an URL involves probing of fault movement and characterization of fault permeability changes. Analyses of barrier samples (bentonite) from heater tests at URLs provide compositional and structural data to evaluate changes in clay swelling and thermal behavior with distance from the heater surface. Development of a spent fuel degradation model coupled with canister corrosion effects has been centered towards its integration with Generic Disposal System Analysis (GDSA) to describe source term behavior. As in previous milestone deliverables, this report is structured according to various national laboratory contributions describing R&D activities applicable to clay/shale/argillite media.

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TYPE Other Report YEAR 2018
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An Example of Counter-Adversarial Community Detection Analysis

Kegelmeyer, William P.; Wendt, Jeremy; Pinar, Ali P.

Community detection is often used to understand the nature of a network. However, there may exist an adversarial member of the network who wishes to evade that understanding. We analyze one such specific situation, quantifying the efficacy of certain attacks against a particular analytic use of community detection and providing a preliminary assessment of a possible defense.

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TYPE SAND Report YEAR 2018
DOIOSTI

Evaluation of Engineered Barrier Systems in the Disposition of Spent Nuclear Fuel

Matteo, Edward N.; Hadgu, Teklu; Zheng, Liange; Xu, Hao; Fox, Patricia; Nico, Peter; Birkholzer, Jens; Caporuscio, Florie A.; Sauer, Kirsten B.; Rock, M.J.; Houser, L.M.

This document is a summary of the R&D activities associated with the Engineered Barrier Systems Work Package. Multiple facets of Engineered Barrier Systems (EBS) research were examined in the course of FY18 activities. This report is focused on delivering an update on the status and progress of modelling tools and experimental methods, both of which are essential to understanding and predicting long-term repository performance as part of the safety case. Specifically, the work described herein aims to improve understanding of EBS component evolution and interactions. Utlimately, the EBS Work Package is working towards producing process models for distinct processes that can either be incorporated into performance assessment (PA), or provide critical information for implementing better constraints on barrier performance The main objective of this work is that the models being developed and refined will either be implemented directly into the Generic Disposal System Analysis platform (GDSA), or can otherwise be indirectly linked to the performance assessment by providing improved bounding conditions. In either the case, the expectation is that validated modelling tools will be developed that provide critical input to the safety case. This report covers a range of topics — modelling topics include: thermal-hydrologic-mechanical-chemical coupling (THMC) in buffer materials, comparisons of modelling approaches to optimize computational efficiency, thermal analysis for EBS/repository design, benchmarking of thermal analysis tools, and a preliminary study of buffer re-saturation processes. Experimental work reported, includes: chemical evolution and sorption behavior of clay-based buffer materials and high-pressure, high temperature studies of EBS material interactions. The work leverages international collaborations to ensure that the DOE program is active and abreast of the latest advances in nuclear waste disposal. This includes participation in the HotBENT Field Test, aimed at understanding near-field effects on EBS materials at temperatures above 100 °C, and the analysis of data and characterization of samples from the FEBEX Field Test. Both the FEBEX and HotBENT Field Tests utilize/utilized the Grimsel Test Site in Switzerland, which is situated in a granite host rock. These tests offer the opportunity to understand near field evolution of bentonite buffer at in situ conditions for either a relatively long timescale (18 years for FEBEX) or temperature above 100 °C (HotBENT). Overall, this report provides in depth descriptions of tools and capabilities to investigate nearfield performance of EBS materials (esp. bentonite buffer), as well as tools for drift-scale thermal and thermal-hydrologic analysis critical to EBS and repository design. For a more detailed description of work contained herein, please see Section 10 ("Conclusions") of this document.

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TYPE Other Report YEAR 2018
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Spectral Methods in Time-dependent Data Analysis

Kumar, Akshat

We aim to create a new model for time-dependent data analysis, named dynamical learning, that integrates data-driven manifold learning techniques with operator-theoretic methods from dynamical systems theory. This approach has the potential to deliver more efficient methods for analyzing time-dependent data, such as video streams, by naturally separating out the temporal and spatial features of the data. We aim to apply the newly developed methods to video surveillance data related to Sandia mission applications, and particularly focus on the problems of image segmentation and object tracking. This project ended early due to the departure of the PI from Sandia about 18 months into the project. Therefore, this document reports on partial progress towards the initial goals of the project. In addition, this document reports on part of the work conducted during the project; see the Appendix for a summary of all the work conducted during the 18 months.

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TYPE SAND Report YEAR 2018
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Results 27201–27400 of 99,299
Results 27201–27400 of 99,299