This report describes challenges associated with the hierarchical Bayesian approach to inform model-form uncertainty (MFU) representations, which are parameterized modifications to a mathematical models' governing equations to express uncertainty in form of the equations.
The SNL Sierra Mechanics code suite is designed to enable simulation of complex multiphysics scenarios. The code suite is composed of several specialized applications which can operate either in standalone mode or coupled with each other. Arpeggio is a supported utility that enables loose coupling of the various Sierra Mechanics applications by providing access to Framework services that facilitate the coupling.
IEEE Transactions on Quantum Engineering
IEEE Transactions on Quantum Engineering
Abstract not provided.
This document details the findings from the FY25 RAD-Tech LDRD titled “Radiation Effects on NoC (Network on Chips).” We utilized the Versal FPGA from AMD as an exemplar platform for NoC. We conducted two radiation tests, one at Texas A&M University (TAMU) in June 2025 and another at Lawrence Berkeley National Laboratory (LBNL) in August 2025. These experiments showed that radiation could upset the NoC and that it experiences a variety of failures, that we could detect those upsets,
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Electrical characterization of Al doped SrTiO3 nanoparticles by undergraduate intern Aaron Coll
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This is the level 3 milestone report (M3) for the workpackage SF-25SN01030407 in the Geologic Disposal Safety Assessment (GDSA) program.
This research project investigates the fundamental mechanisms of silicon nitride (SiN) crystallization, aiming to enhance the understanding of this critical material in microelectronics manufacturing. Through a collaborative effort between Sandia National Laboratories, the University of Tennessee, and the University of Florida, we developed a comprehensive framework that integrates experimental techniques, atomistic modeling, meso-scale simulations, and an integrated multi-scale model to capture
Health Physics
The National Nuclear Security Administration (NNSA) seeks to assist and support all partners in the fields of radiobiology, health physics, radiation physics, and related areas to transition from cesium-137 chloride-based technologies that can potentially be used in an act of terrorism to X-ray technologies. The absence of information on experimental procedures, equipment, and irradiation parameters directly and negatively impacts the reproducibility and translatability of a sizable portion of radiation biology studies. It also discourages researchers from adopting new tools that eliminate the risks of a radiological dispersal device.
This project extends the state of the art in formal verification modeling with modules and automatically checkable data-sharing patterns such that component modules can retain their assurance case when composed within a larger system. For users, smaller models make reasoning easier and help to ensure they accurately reflect text specifications. For automated methods, smaller models give exponential benefits for verification algorithm execution time.
This report evaluates leakage behavior from tritium containment vessels under thermal abuse and combined thermal-mechanical abuse conditions to better understand safety implications for releases occurring in a fire scenario. Surrogate gases were used for all tests in this report. Leakage through the valves from thermal pressurization was observed when heating rates >0.8°C/s were sustained to >300°C. Gas plumes were visualized from vessels that were heated above 260°C and then dropped.
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LDRD Small project report
Data
We present a curated, openly accessible dataset of 71 regional meteor events simultaneously recorded by optical and infrasound instrumentation between 2006 and 2011. These events were captured during an observational campaign using the all-sky cameras of the Southern Ontario Meteor Network and the co-located Elginfield Infrasound Array. Each entry provides optical trajectory measurements, infrasound waveforms, and atmospheric specification profiles. The integration of optical and acoustic data enables robust linkage between observed acoustic signals and specific points along meteor trajectories, offering new opportunities to examine shock wave generation, propagation, and energy deposition processes. This release fills a critical observational gap by providing the first validated, openly accessible archive of simultaneous optical–infrasound meteor observations that supports trajectory reconstruction, acoustic propagation modeling, and energy deposition analyses. By making these data openly available in a structured format, this work establishes a durable reference resource that advances reproducibility, fosters cross-disciplinary research, and underpins future developments in meteor physics, atmospheric acoustics, and planetary defense. Dataset: https://doi.org/10.5281/zenodo.15868512. Dataset License: CC-BY-NC
Nanoguide optical waveguides are thermally processed materials based on polymers that have different refractive indices. Scintillating versions of these materials have been under development since 2019 and feature PMMA as the low refractive index constituent and Organic Glass Scintillator-polymer blends as the high index component. Characterization efforts to date have focused on the functional characteristics of nanoguide pertaining to its envisioned use in high-resolution transmission radiogra
The SNL-developed F3M and MAPIT tools have the capability to analyze MC&A approaches for nuclear facilities via facility process flow simulation and statistical tests. Improvements on the application of F3M and MAPIT in simulating a generic TRISO fuel fabrication facility were successfully completed. This modeling framework can support the U.S. DOE and industry stakeholders in developing MC&A approaches for fuel fabrication facilities via demonstration of regulatory compliance.
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This report summarizes accomplishments in the development and maintenance of modeling and simulation tools to support material accountancy of bulk nuclear facilities. In FY25, we added new capabilities to MAPIT (new statistical test, improved error handling), launched the open source F3M modeling library, and added three new facility models to the SSPM-L model library.
A series of experiments where deuterium was released in trace amounts into a room with a fire were performed at Sandia. This report describes the corresponding effort to model the test series using SIERRA/FUEGO. The objective of this modeling effort was to produce a simulation test matrix that can be utilized to help interpret the corresponding experiments and be used to assess the credibility of using the SIERRA/FUEGO simulations as a surrogate for real tritium reaction data.