Publications

Results 51–100 of 174
Skip to search filters

NSRD-16: Computational Capability to Substantiate DOE-HDBk-3010 Data

Louie, David L.; Bignell, John B.; Le, San L.; Dingreville, Remi P.; Gilkey, Lindsay N.; Gordon, Natalie G.; Fascitelli, Dominic G.

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 from postulated accident scenarios. 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.

More Details

Stability of sea-salt deliquescent brines on heated surfaces of SNF dry storage canisters

International High-Level Radioactive Waste Management 2019, IHLRWM 2019

Bryan, Charles R.; Schindelholz, Eric J.; Knight, Andrew W.; Taylor, Jason M.; Dingreville, Remi P.

For long-term storage, spent nuclear fuel (SNF) is placed in dry storage systems, commonly consisting of welded stainless steel canisters enclosed in ventilated overpacks. Choride-induced stress corrosion cracking (CISCC) of these canisters may occur due to the deliquescence of sea-salt aerosols as the canisters cool. Current experimental and modeling efforts to evaluate canister CISCC assume that the deliquescent brines, once formed, persist on the metal surface, without changing chemical or physical properties. Here we present data that show that magnesium chloride rich-brines, which form first as the canisters cool and sea-salts deliquesce, are not stable at elevated temperatures, degassing HCl and converting to solid carbonates and hydroxychloride phases, thus limiting conditions for corrosion. Moreover, once pitting corrosion begins on the metal surface, oxygen reduction in the cathode region surrounding the pits produces hydroxide ions, increasing the pH under some experimental conditions, leads to precipitation of magnesium hydroxychloride hydrates. Because magnesium carbonates and hydroxychloride hydrates are less deliquescent than magnesium chloride, precipitation of these compounds causes a reduction in the brine volume on the metal surface, potentially limiting the extent of corrosion. If taken to completion, such reactions may lead to brine dry-out, and cessation of corrosion.

More Details

Posters for AA/CE Reception

Kuether, Robert J.; Allensworth, Brooke M.; Backer, Adam B.; Chen, Elton Y.; Dingreville, Remi P.; Forrest, Eric C.; Knepper, Robert; Tappan, Alexander S.; Marquez, Michael P.; Vasiliauskas, Jonathan G.; Rupper, Stephen G.; Grant, Michael J.; Atencio, Lauren C.; Hipple, Tyler J.; Maes, Danae M.; Timlin, Jerilyn A.; Ma, Tian J.; Garcia, Rudy J.; Danford, Forest L.; Patrizi, Laura P.; Galasso, Jennifer G.; Draelos, Timothy J.; Gunda, Thushara G.; Venezuela, Otoniel V.; Brooks, Wesley A.; Anthony, Stephen M.; Carson, Bryan C.; Reeves, Michael J.; Roach, Matthew R.; Maines, Erin M.; Lavin, Judith M.; Whetten, Shaun R.; Swiler, Laura P.

Abstract not provided.

Fundamentals of Pellet-Clad Debonding

Dingreville, Remi P.; Hattar, Khalid M.; Boyle, Timothy J.; Monterrosa, Anthony M.; Barr, Christopher M.; Weck, Philippe F.; Juan, Pierre-Alexandre J.

This project focused on providing a fundamental mechanistic understanding of the complex degra- dation mechanisms associated with Pellet/Clad Debonding (PCD) through the use of a unique suite of novel synthesis of surrogate spent nuclear fuel, in-situ nanoscale experiments on surrogate interfaces, multi-modeling, and characterization of decommissioned commercial spent fuel. The understanding of a broad class of metal/ceramic interfaces degradation studied within this project provided the technical basis related to the safety of high burn-up fuel, a problem of interest to the DOE.

More Details

Density functional analysis of fluorite-structured (Ce, Zr)O2/CeO2 interfaces [Density functional analysis of fluorite-structured (Ce, Zr)O2/CeO2 interfaces: Implications for catalysis and energy applications]

Journal of Physical Chemistry. C

Weck, Philippe F.; Juan, Pierre-Alexandre J.; Dingreville, Remi P.; Kim, Eunja K.

The structures and properties of Ce1–xZrxO2 (x = 0–1) solid solutions, selected Ce1–xZrxO2 surfaces, and Ce1–xZrxO2/CeO2 interfaces were computed within the framework of density functional theory corrected for strong electron correlation (DFT+U). The calculated Debye temperature increases steadily with Zr content in (Ce, Zr)O2 phases, indicating a significant rise in microhardness from CeO2 to ZrO2, without appreciable loss in ductility as the interfacial stoichiometry changes. Surface energy calculations for the low-index CeO2(111) and (110) surfaces show limited sensitivity to strong 4f-electron correlation. The fracture energy of Ce1–xZrxO2(111)/CeO2(111) increases markedly with Zr content, with a significant decrease in energy for thicker Ce1–xZrxO2 films. These findings suggest the crucial role of Zr acting as a binder at the Ce1–xZrxO2/CeO2 interfaces, due to the more covalent character of Zr–O bonds compared to Ce–O. Finally, the impact of surface relaxation upon interface cracking was assessed and found to reach a maximum for Ce0.25Zr0.75O2/CeO2 interfaces.

More Details
Results 51–100 of 174
Results 51–100 of 174