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FY18 Status Report: SNL Research into Stress Corrosion Cracking of SNF Interim Storage Canisters

Bryan, Charles R.; Schindelholz, Eric J.

This progress report describes work done in FY18 at Sandia National Laboratories (SNL) to assess the localized corrosion performance of container/cask materials used in the interim storage of spent nuclear fuel (SNF). The work focuses on stress corrosion cracking (SCC), the only mechanism by which a through-wall crack could potentially form in a canister outer wall over time intervals that are shorter than possible dry storage times. Work in FY18 continued several studies initiated in FY17 that are aimed at refining the understanding of the chemical and physical environment on canister surfaces, and evaluating the relationship between chemical and physical environment and the form and extent of corrosion that occurs. The SNL canister environment work focused on evaluating the stability of sea-salt deliquescent brines on the heated canister surface; an additional opportunity to analyze dusts sampled from an inservice spent nuclear fuel storage canister also arose. The SNL corrosion work focused predominantly on pitting corrosion, a necessary precursor for SCC, and process of pit-to-crack transition. SNL is collaborating with several university partners to investigate SCC crack growth experimentally, providing guidance for design and interpretation of experiments. The scope of these efforts targets near-marine Independent Spent Fuel Storage Installation environments which are generally considered to be most aggressive for pitting and SCC. Work to define the chemical and physical environment that could develop on storage canister surfaces in near-marine environments included experiments to evaluate the thermal stability of magnesium chloride brines, representative of the first brines to form when sea-salts deliquesce, with the specific goal of understanding and interpreting results of sea-salt and magnesium chloride corrosion experiments carried out under accelerated conditions. The experiments showed that magnesium chloride brines, and by extension, low RH sea-salt deliquescent brines, are not stable at elevated temperatures, losing chloride via degassing of HC1 and conversion to Mg-hydroxychlorides and carbonates. The experiments were carried out on an inert substrate to eliminate the effects of corrosion reactions, simulating brine stabilities in the absence of, or prior to, corrosion. Moreover, analysis of salts recovered from actively corroding metal samples shows that corrosion also supports or drives conversion of magnesium chloride or sea-salt brines to less deliquescent salts. This process has significant implications on corrosion, as the secondary phases are less deliquescent than magnesium chloride; the conversion reaction results in decreases in brine volume, and potentially results in brine dry-out. The deliquescence properties of these reaction products will be a topic of active research in FY19.

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TYPE Other Report YEAR 2018
DOIOSTI

Enhancements to the Munson-Dawson Model for Rock Salt

Reedlunn, Benjamin R.

The Munson-Dawson (MD) constitutive model was originally developed in the 1980's to predict the thermomechanical behavior of rock salt. Since then, it has been used to simulate the evolution of the underground in nuclear waste repositories, mines, and storage caverns for gases and liquids. This report covers three enhancements to the MD model. (1) New transient and steady-state rate terms were added to capture salt's creep behavior at low equivalent stresses (below about 8 MPa). These new terms were calibrated against a series of triaxial compression creep experiments on salt from the Waste Isolation Pilot Plant. (2) The equivalent stress measure was changed from the Tresca stress to the Hosford stress. By varying a single exponent, the Hosford stress can reduce to the Tresca stress, the von Mises stress, or a range of behaviors in-between. This exponent was calibrated against true triaxial compression experiments on salt hollow cylinders. (3) The MD model's numerical implementation was overhauled, adding a line search algorithm to the implicit solution scheme. The new implementation was verified against analytical solutions, and benchmarked against a pre-existing implementation on a room closure simulation. The new implementation pre- dicted virtually identical room closure, yet sped up the simulation by 16x . (The source code of the new implementation is included in an appendix of this report.)

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TYPE SAND Report YEAR 2018
DOIOSTI

Summary paragraphs for recently-awarded DOE-SC projects at Sandia in Quantum Information Science

Muller, Richard P.

Sandia National Laboratories was recently awarded 3 new projects in Quantum Information Science (QIS) by the Department of Energy's Advanced Scientific Computing Research (ASCR) program and 2 new projects in quantum technologies both DOE's Basic Energy Sciences. Two of the ASCR projects are for work in quantum testbeds, while the third is in the area of quantum algorithms. A fourth QIS project was awarded in FY17, also in the area of quantum algorithms.

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TYPE Other Report YEAR 2018
DOIOSTI

Detecing Surface Change Created by an Underground Chemical Explosion Using Fully Polarimetric VideoSAR

Yocky, David A.; West, Roger D.; Riley, Robert; Calloway, Terry M.; Wahl, Daniel E.; Laros, James H.; Bolin, Samuel A.

Sandia National Laboratories (SNL) flew its Facility for Advanced RF and Algorithm Development (FARAD) X-Band (9.6 GHz center frequency), fully-polarimetric synthetic aperture radar (PolSAR) in VideoSAR-mode to collect complex-valued SAR imagery before, during, and after the fifth and sixth Source Physics Experiment's (SPE-5 and SPE-6) underground explosion. The results from the fifth Source Physics Experiment (SPE-5) used single-polarimetric VideoSAR data while SPE-6 used single and fully-polarimetric VideoSAR data. We show that SAR can provide surface change products indicative of disturbances caused by the underground chemical explosions. These are surface coherence measures, Po1SAR change signatures, and differential interferometric SAR (InSAR) height change.

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TYPE Other Report YEAR 2018
DOIOSTI

Challenges in Eye Tracking for Dynamic User-Driven Workflows

McNamara, Laura A.; Divis, Kristin; Morrow, James D.; Chen, Maximillian G.; Perkins, David

This three-year Laboratory Directed Research and Development (LDRD) project aimed at developing a developed prototype data collection system and analysis techniques to enable the measurement and analysis of user-driven dynamic workflows. Over 3 years, our team developed software, algorithms, and analysis technique to explore the feasibility of capturing and automatically associating eye tracking data with geospatial content, in a user-directed, dynamic visual search task. Although this was a small LDRD, we demonstrated the feasibility of automatically capturing, associating, and expressing gaze events in terms of geospatial image coordinates, even as the human "analyst" is given complete freedom to manipulate the stimulus image during a visual search task. This report describes the problem under examination, our approach, the techniques and software we developed, key achievements, ideas that did not work as we had hoped, and unsolved problems we hope to tackle in future projects.

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TYPE SAND Report YEAR 2018
DOIOSTI

FY19 Annual Report Advanced Light-Duty SI Engine Fuels Research

Sjoberg, Carl M.G.

This project furthers the science-base needed by industry stakeholder to co-evolve the next generations of highly efficient DISI engines and new gasoline-type fuels. Here, the research emphasis is on lean operation, which can provide high efficiency, using fuels that also support traditional non-dilute stoichiometric operation for peak load and power. Lean operation induces challenges with ignition stability, slow flame propagation and low combustion efficiency. Therefore, techniques that can overcome these challenges are studied. Specifically, fuel stratification is used to ensure ignition and completeness of combustion, but this technique has soot- and NOx- emissions challenges. For ultra-lean well-mixed operation, turbulent deflagration can be combined with controlled end-gas autoignition to render mixed-mode combustion for sufficiently fast heat release. However, such mixed-mode combustion requires appropriate autoignition reactivity, motivating fuel studies of autoignition under lean conditions.

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TYPE Other Report YEAR 2018
DOIOSTI

Industrial Internet-of-Things & Data Analytics for Nuclear Power & Safeguards

Farley, David R.; Negus, Mitch G.; Slaybaugh, Rachel N.

Data analytics applied to nuclear power operations and nuclear safeguards is in a nascent state, yet some significant initial efforts are being undertaken by industry and academia. This report highlights our findings as to the current state-of-the-art of such efforts, in particular considering the Industrial Internet-of-Things aspect of this work, as well as an investigation into the utility of machine learning tools being developed for other industries. Blockchain applications were also studied. A consideration was undertaken into how to apply data analytics and machine learning to nuclear power and safeguards within the realm of Probabilistic Risk Assessments (PRAs), predictive maintenance & edge analytics, and proprietary data sharing.

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TYPE SAND Report YEAR 2018
DOIOSTI

Progress toward a compact high-efficiency neutron scatter camera

Brown, Joshua A.; Brubaker, Erik B.; Cabrera-Palmer, Belkis C.; Druetzler, Andy; Elam, Jeff; Febbraro, Michael; Feng, Patrick L.; Folsom, Micah; Goldblum, Bethany; Hausladen, Paul; Kaneshige, Nate; Laplace, Thibault; Learned, John; Mane, Anil; Marleau, Peter M.; Mattingly, John; Mishra, Mudit; Nishimura, Kurtis; Steele, John T.; Sweany, Melinda; Ziock, Klaus

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

MELCOR Modeling of Non-LWR Systems Draft Report for the Nuclear Regulatory Commission

Beeny, Bradley A.; Humphries, Larry

This report provides an overview of technical issues and design features relevant to advanced reactors and reviews MELCOR's current readiness for modeling accidents in such reactor types. This report describes advanced reactor physics models currently available or under development, and gauges the level of effort required to develop new models and capabilities applicable to assessing advanced reactor safety issues. Finally, this report reviews the available database that can be used in verification and validation of new models. Four general advanced reactor types are considered in this report: 1) High Temperature Gas-Cooled Reactor (HTGR); 2) Sodium Fast Reactor (SFR); 3) Molten Salt Reactor (MSR); 4) Fluoride Salt-Cooled High Temperature Reactor (FHR)

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TYPE SAND Report YEAR 2018
DOIOSTI

Terry Turbopump Expanded Operating Band Full-Scale Integral Long-Term Low-Pressure Experiments — Preliminary Test Plan

Osborn, Douglas M.; Solom, Matthew A.

This document details the milestone approach to define the true operating limitations (margins) of the Terry turbopump systems used in the nuclear industry for Milestone 5 (full-scale integral long-term low-pressure operations) efforts. The overall multinational-sponsored program creates the technical basis to: (1) reduce and defer additional utility costs, (2) simplify plant operations, and (3) provide a better understanding of the true margin which could reduce overall risk of operations.

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TYPE SAND Report YEAR 2018
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Thickness scaling of pyroelectric response in thin ferroelectric Hf 1-xZr xO2 films

Applied Physics Letters

Smith, Sean S.; Henry, Michael D.; Brumbach, Michael T.; Rodriguez, Mark A.; Ihlefeld, Jon F.

In this study, the scaling of polarization and pyroelectric response across a thickness series (5–20 nm) of Hf0.58Zr0.42O2 films with TaN electrodes was characterized. Reduction in thickness from 20 nm to 5 nm resulted in a decreased remanent polarization from 17 to 2.8 μC cm-2. Accompanying the decreased remanent polarization was an increased absolute pyroelectric coefficient, from 30 to 58 μC m-2 K-1. The pyroelectric response of the 5 nm film was unstable and decreased logarithmically with time, while that of 10 nm and thicker films was stable over a time scale of >300 h at room temperature. Finally, the sign of the pyroelectric response was irreversible with differing polarity of poling bias for the 5 nm thick film, indicating that the enhanced pyroelectric response was of electret origins, whereas the pyroelectric response in thicker films was consistent with a crystallographic origin.

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TYPE Journal Article YEAR 2018
DOIOSTI

Uncovering signatures of preheat performance in MagLIF experiments using stimulated Raman and Brillouin backscatter spectra

Fein, Jeffrey R.; Bliss, David E.; Geissel, Matthias G.; Harvey-Thompson, Adam J.; Awe, Thomas J.; Ampleford, David A.; Glinsky, Michael E.; Laros, James H.; Harding, Eric H.; Macrunnels, K.A.; Patel, Sonal P.; Ruiz, Daniel E.; Scoglietti, Daniel S.; Smith, Ian C.; Weis, Matthew R.; Peterson, Kara J.

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

Application Note: Mixed Signal Simulation with Xyce™

Sholander, Peter E.; Schiek, Richard S.

This application note describes how the Xyce circuit simulator can be coupled with external simulators via either a Python-based interface that leverages the Python ctypes foreign function library or via the Verilog Procedural Interface (VPI). It also documents the usage of these interfaces on RHEL6 and RHEL7, with Python 2.6 or 2.7. These interfaces are still under development and may change in the future. So, a key purpose of this application note is to solicit feedback on these interfaces from both internal Sandia Xyce users and other performers on the DARPA Posh Open Source Hardware (POSH) program.

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TYPE SAND Report YEAR 2018
DOIOSTI

Acoustic Chamber Characterization

O'Brien, Edward O.; Kypta, Timothy K.; Stanford, Joshua S.; Tran, Hy D.

The basis of this project was to characterize the various uncertainty contributors of an acoustic chamber. The acoustic chamber will be used to calibrate and characterize infrasound sensors used in the field in the frequency range of 0.001 Hz to 4 Hz. The components characterized include the internal volume of the chamber, the piston area of the speaker creating the dynamic sound wave, the environmental stabilization of the chamber and the chamber's leak rate. Also, the resonant frequency of the chamber was evaluated and found to be far outside the frequency band of interest.

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TYPE SAND Report YEAR 2018
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Results 25001–25200 of 96,771
Results 25001–25200 of 96,771