Publications

Results 27201–27400 of 96,771

Search results

Jump to search filters

Role of refractory inclusions in the radiation-induced microstructure of APMT

Journal of Nuclear Materials

Zhang, Dalong; Briggs, Samuel B.; Field, Kevin G.

Kanthal APMT is a promising FeCrAl-based alloy for accident-tolerant fuel cladding because of its excellent high-temperature oxidation resistance. In this study, powder metallurgy Kanthal APMT alloy, neutron irradiated to 1.8 dpa at nominally 382 °C, was characterized. On-zone STEM imaging revealed that radiation-induced dislocation loops with Burgers vectors of a/2〈111〉 or a〈100〉 and black dots tended to agglomerate in the vicinity of refractory inclusions. The densities and sizes of these loops decreased with distance from the inclusion-matrix interfaces. In addition, high-resolution energy-dispersive X-ray spectroscopy mapping was used to determine the inclusions to be either yttrium- or silicon-rich, as well as to detect the radial distribution of radiation-enhanced α′ phase near these inclusions. A high density of randomly distributed Cr-rich α′ phase was found, regardless of the presence of inclusions. Results from this study provide insights into how microstructural features can locally tailor the radiation-induced defects in FeCrAl-based alloys.

More Details
TYPE Journal Article YEAR 2018
DOIOSTIScopus

Industrial Control Systems: Cyber Security Risk Candidate Methods Analysis

Dawson, Lon A.; Lamb, Christopher L.; Carbajal, Armida J.

In recognition of their mission and in response to continuously evolving cyber threats against nuclear facilities, Department of Energy - Nuclear Energy (DOE-NE) is building the Nuclear Energy Cyber security Research, Development, and Demonstration (RD&D) Program, which includes a cyber risk management thrust. This report supports the cyber risk management thrust objective which is to deliver "Standardized methodologies for credible risk-based identification, evaluation and prioritization of digital components." In a previous task, the Sandia National Laboratories (SNL) team presented evaluation criteria and a survey to review methods to determine the most suitable techniques. In this task we will identify and evaluate a series of candidate methodologies. In this report, 10 distinct methodologies are evaluated. The overall goal of this effort was to identify the current range of risk analysis techniques that were currently available, and how they could be applied, with an focus on industrial control systems (ICS). Overall, most of the techniques identified did fall into accepted risk analysis practices, though they generally addressed only one step of the multi-step risk management process. A few addressed multiple steps, but generally their treatment was superficial. This study revealed that the current state of security risk analysis in digital control systems was not comprehensive and did not support a science-based evaluation. The papers surveyed did use mathematical formulation to describe the addressed problems, and tied the models to some kind of experimental or experiential evidence as support. Most of the papers, however, did not use a rigorous approach to experimentally support the proposed models, nor did they have enough evidence supporting the efficacy of the models to statistically analyze model impact. Both of these issues stem from the difficulty and expense associated with collecting experimental data in this domain.

More Details
TYPE SAND Report YEAR 2018
DOIOSTI
Results 27201–27400 of 96,771
Results 27201–27400 of 96,771