Publications

Results 64801–65000 of 96,771

Search results

Jump to search filters

Fully integrated safeguards and security for reprocessing plant monitoring

Cipiti, Benjamin B.; Duran, Felicia A.; Middleton, Bobby M.; Key, Rebecca K.

Nuclear fuel reprocessing plants contain a wealth of plant monitoring data including material measurements, process monitoring, administrative procedures, and physical protection elements. Future facilities are moving in the direction of highly-integrated plant monitoring systems that make efficient use of the plant data to improve monitoring and reduce costs. The Separations and Safeguards Performance Model (SSPM) is an analysis tool that is used for modeling advanced monitoring systems and to determine system response under diversion scenarios. This report both describes the architecture for such a future monitoring system and present results under various diversion scenarios. Improvements made in the past year include the development of statistical tests for detecting material loss, the integration of material balance alarms to improve physical protection, and the integration of administrative procedures. The SSPM has been used to demonstrate how advanced instrumentation (as developed in the Material Protection, Accounting, and Control Technologies campaign) can benefit the overall safeguards system as well as how all instrumentation is tied into the physical protection system. This concept has the potential to greatly improve the probability of detection for both abrupt and protracted diversion of nuclear material.

More Details
TYPE SAND Report YEAR 2011
DOIOSTI

Confined cooperative self-assembly and synthesis of optically and electrically active nanostructures : final LDRD report

Coker, Eric N.; Huang, Jian Y.; Rodriguez, M.A.

In this project, we developed a confined cooperative self-assembly process to synthesize one-dimensional (1D) j-aggregates including nanowires and nanorods with controlled diameters and aspect ratios. The facile and versatile aqueous solution process assimilates photo-active macrocyclic building blocks inside surfactant micelles, forming stable single-crystalline high surface area nanoporous frameworks with well-defined external morphology defined by the building block packing. Characterizations using TEM, SEM, XRD, N{sub 2} and NO sorption isotherms, TGA, UV-vis spectroscopy, and fluorescence imaging and spectroscopy indicate that the j-aggregate nanostructures are monodisperse and may further assemble into hierarchical arrays with multi-modal functional pores. The nanostructures exhibit enhanced and collective optical properties over the individual chromophores. This project was a small footprint research effort which, nonetheless, produced significant progress towards both the stated goal as well as unanticipated research directions.

More Details
TYPE SAND Report YEAR 2011
DOIOSTI

Room temperature detector array technology for the terahertz to far-infrared

Shaner, Eric A.; Wright, Jeremy B.; Kadlec, Emil A.; Shaw, Michael S.; Lentine, Anthony L.; Rakich, Peter T.; Camacho, Ryan C.

Thermal detection has made extensive progress in the last 40 years, however, the speed and detectivity can still be improved. The advancement of silicon photonic microring resonators has made them intriguing for detection devices due to their small size and high quality factors. Implementing silicon photonic microring or microdisk resonators as a means of a thermal detector gives rise to higher speed and detectivity, as well as lower noise compared to conventional devices with electrical readouts. This LDRD effort explored the design and measurements of silicon photonic microdisk resonators used for thermal detection. The characteristic values, consisting of the thermal time constant ({tau} {approx} 2 ms) and noise equivalent power were measured and found to surpass the performance of the best microbolometers. Furthermore the detectivity was found to be D{sub {lambda}} = 2.47 x 10{sup 8} cm {center_dot} {radical}Hz/W at 10.6 {mu}m which is comparable to commercial detectors. Subsequent design modifications should increase the detectivity by another order of magnitude. Thermal detection in the terahertz (THz) remains underdeveloped, opening a door for new innovative technologies such as metamaterial enhanced detectors. This project also explored the use of metamaterials in conjunction with a cantilever design for detection in the THz region and demonstrated the use of metamaterials as custom thin film absorbers for thermal detection. While much work remains to integrate these technologies into a unified platform, the early stages of research show promising futures for use in thermal detection.

More Details
TYPE SAND Report YEAR 2011
DOIOSTI

Augmented cognition tool for rapid military decision making

Vineyard, Craig M.; Verzi, Stephen J.; Taylor, Shawn E.; Dubicka, Irene D.; Bernard, Michael L.

This report describes the laboratory directed research and development work to model relevant areas of the brain that associate multi-modal information for long-term storage for the purpose of creating a more effective, and more automated, association mechanism to support rapid decision making. Using the biology and functionality of the hippocampus as an analogy or inspiration, we have developed an artificial neural network architecture to associate k-tuples (paired associates) of multimodal input records. The architecture is composed of coupled unimodal self-organizing neural modules that learn generalizations of unimodal components of the input record. Cross modal associations, stored as a higher-order tensor, are learned incrementally as these generalizations form. Graph algorithms are then applied to the tensor to extract multi-modal association networks formed during learning. Doing so yields a novel approach to data mining for knowledge discovery. This report describes the neurobiological inspiration, architecture, and operational characteristics of our model, and also provides a real world terrorist network example to illustrate the model's functionality.

More Details
TYPE SAND Report YEAR 2011
DOIOSTI

Refinery burner simulation design architecture summary

Pollock, Guylaine M.; McDonald, Michael J.; Halbgewachs, Ronald D.

This report describes the architectural design for a high fidelity simulation of a refinery and refinery burner, including demonstrations of impacts to the refinery if errors occur during the refinery process. The refinery burner model and simulation are a part of the capabilities within the Sandia National Laboratories Virtual Control System Environment (VCSE). Three components comprise the simulation: HMIs developed with commercial SCADA software, a PLC controller, and visualization software. All of these components run on different machines. This design, documented after the simulation development, incorporates aspects not traditionally seen in an architectural design, but that were utilized in this particular demonstration development. Key to the success of this model development and presented in this report are the concepts of the multiple aspects of model design and development that must be considered to capture the necessary model representation fidelity of the physical systems.

More Details
TYPE SAND Report YEAR 2011
DOIOSTI

SNL software manual for the ACS Data Analytics Project

Stearley, Jon S.; Robinson, David G.; Hooper, Russell H.; Stickland, Michael S.; McLendon, William C.; Williams, Aaron S.; Rodrigues, Arun

In the ACS Data Analytics Project (also known as 'YumYum'), a supercomputer is modeled as a graph of components and dependencies, jobs and faults are simulated, and component fault rates are estimated using the graph structure and job pass/fail outcomes. This report documents the successful completion of all SNL deliverables and tasks, describes the software written by SNL for the project, and presents the data it generates. Readers should understand what the software tools are, how they fit together, and how to use them to reproduce the presented data and additional experiments as desired. The SNL YumYum tools provide the novel simulation and inference capabilities desired by ACS. SNL also developed and implemented a new algorithm, which provides faster estimates, at finer component granularity, on arbitrary directed acyclic graphs.

More Details
TYPE SAND Report YEAR 2011
DOIOSTI
Results 64801–65000 of 96,771
Results 64801–65000 of 96,771