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At least 829 records · Page 46

Dual phase magnetic material component and method of forming

A magnetic component having intermixed first and second regions, and a method of preparing that magnetic component are disclosed. The first region includes a magnetic phase and the second region includes a non-magnetic phase. The method includes mechanically masking pre-selected sections of a surface portion of the component by using a nitrogen stop-off material and heat-treating the component in a nitrogen-rich atmosphere at a temperature greater than about 900.degree. C. Both the first and second regions are substantially free of carbon, or contain only limited amounts of carbon; and the second region includes greater than about 0.1 weight % of nitrogen.

36 MATERIALS SCIENCE↗

Hot gas path component

Various embodiments of the disclosure include a turbomachine component. and methods of forming such a component. Some embodiments include a turbomachine component including: a first portion including at least one of a stainless steel or an alloy steel; and a second portion joined with the first portion, the second portion including a nickel alloy including an arced cooling feature extending therethrough, the second portion having a thermal expansion coefficient substantially similar to a thermal expansion coefficient of the first portion, wherein the arced cooling feature is located within the second portion to direct a portion of a coolant to a leakage area of the turbomachine component.

42 ENGINEERING↗

Mitigating component performance variation

Apparatus and methods may provide for characterizing a plurality of similar components of a distributed computing system based on a maximum safe operation level associated with each component and storing characterization data in a database and allocating non-uniform power to each similar component based at least in part on the characterization data in the database to substantially equalize performance of the components.

97 MATHEMATICS AND COMPUTING↗

Defect screening method for electronic circuits and circuit components using power spectrum anaylysis

A method involving the non-destructive testing of a sample electrical or electronic device is provided. The method includes measuring a power spectrum of the device and performing a Principal Component Analysis on the power spectrum, thereby to obtain a set of principal components of the power spectrum. The method further includes selecting a subset consisting of some of the principal components, and comparing the subset to stored reference data that include representations in terms of principal components of one or more reference populations of devices. Based at least partly on the comparison, the sample device is classified relative to the reference populations.

Tangyunyong, Paiboon↗

Dual phase magnetic material component and method of forming

A magnetic component having intermixed first and second regions, and a method of preparing that magnetic component are disclosed. The first region includes a magnetic phase and the second region includes a non-magnetic phase. The method includes mechanically masking pre-selected sections of a surface portion of the component by using a nitrogen stop-off material and heat-treating the component in a nitrogen-rich atmosphere at a temperature greater than about 900.degree. C. Both the first and second regions are substantially free of carbon, or contain only limited amounts of carbon; and the second region includes greater than about 0.1 weight % of nitrogen.

Dial, Laura Cerully↗

Hot gas path component and methods of manufacture

Various embodiments of the disclosure include a turbomachine component. and methods of forming such a component. Some embodiments include a turbomachine component including: a first portion including at least one of a stainless steel or an alloy steel; and a second portion joined with the first portion, the second portion including a nickel alloy including an arced cooling feature extending therethrough, the second portion having a thermal expansion coefficient substantially similar to a thermal expansion coefficient of the first portion, wherein the arced cooling feature is located within the second portion to direct a portion of a coolant to a leakage area of the turbomachine component.

36 MATERIALS SCIENCE↗

Method for separating components using solids producing multi-stage direct and indirect-contact exchange

A process for forming a solid product or products is disclosed. The process is provided with n desublimating exchangers. An exchanger E1 being associated with a first exchanger and an exchanger En being associated with an nth exchanger, n representing the number of exchangers. The n exchangers comprise at least one direct-contact exchanger comprising a contact fluid. A process fluid is passed through the n exchangers in order from E1 through En. The process fluid comprises a product component or components. The solid product or products form from the product component or components in the plurality of exchangers by desublimation. The solid product or products are separated from the process fluid. In this manner, a solid product or products is formed.

36 MATERIALS SCIENCE↗

Component removal from a gas stream

In a first aspect, the disclosure provides a method for removing a component from a gas stream. A carrier gas stream is cooled by direct contact with a dehydrating solution stream. The dehydrating solution stream removes a portion of water present in the carrier gas stream and produces a dry gas stream and a wet solution stream. A portion of the component is removed from the dry gas stream by direct contact with a cold contact liquid stream. A depleted gas stream and a slurry stream are produced. Removing the portion of the component may include desublimating, freezing, condensing, depositing, or a combination thereof of the portion of the component out of the dry gas stream as a solid product. The slurry stream may include the solid product and a contact liquid. The solid product is separated from the contact liquid, producing a substantially pure solid product stream and the cold contact liquid stream.

42 ENGINEERING↗

Development of scalable design optimization parameters for bi-component protective systems

Bi-component protection-systems need to withstand a variety of extreme loading conditions such as high-velocity projectile impact to shock and blast mitigation. The large number of parameters at each stage of bi-component protection system design process results in a near-infinite number of possible variables for optimization. The aim of this project is to identify the scaling laws linking material and geometric scales of the problem to the final impact performance, further including the effects of wave propagation/interaction and inter-component bonding. Specifically, the impact dynamics for different optimal projectile/target density ratios and relative component mass fractions are quantified for bonded ceramic/titanium alloy systems. The impact behavior such as wave mechanics and damage propagation within the target system is characterized and quantified via digital image correlation or via x-ray phase-contrast imaging.

36 MATERIALS SCIENCE↗

Establishment of technical basis to implement accident tolerant fuels and component to existing LWRs

Fuel cladding, channel box, and control rod designed with new materials and concepts have been developed in Japan for increasing accident tolerance of Light Water Reactors (LWRs). Fundamental data have been mainly accumulated from the viewpoint of material technology. In order to create the technical basis for the practical use of the accident tolerant fuels (ATFs) and the other components in LWRs, a program sponsored and organized by the Ministry of Economy, Trade and Industry (METI) of Japan has been initiated. Main candidate materials of the ATFs and components in Japan are silicon carbide (SiC), stainless steel including oxide-dispersion strengthened (ODS) FeCrAl alloys, and tri-structural-isotropic (TRISO) fuel. First of all, current status of development of the candidates was investigated using information released from inside and outside Japan. Based on the results of the investigation, technology readiness of the candidates was evaluated and the attribute guide was created to clarify technical subjects for the practical use as the core components of the existing LWRs. For that purpose, a technology readiness table was reviewed in terms of fuel rod design, production and quality management, core and plant design, safety evaluation for design basis accident and severe accident, safety evaluation for transport and storage, establishment of treatment and disposal technologies, and development of standards and criteria, with 9 readiness levels. Considering the reviewed technology readiness table and the additionally evaluated influence of implementation of the new materials, a map of remaining subjects for research/development (Attribute guide) was prepared. Finally, a research plan was drafted for design and fabrication towards implementation of ATFs and components to the existing LWRs. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Evaluation of Nonmetallic Components in the Hanford Waste Transfer System - 17287

Nonmetallic materials are currently being used in the United States Department of Energy's Hanford Site Tank Farm waste transfer system. These materials include the inner primary hoses in the hose-in-hose transfer lines (HIHTLs), Garlock{sup R} gaskets, ethylene propylene diene monomer (EPDM) O-rings. These materials are exposed to a number of stressors and the synergistic effects are not well understood. Florida International University (FIU) engineers have developed an experimental test loop to determine how the nonmetallic materials react to both individual and simultaneous stressors. The initial phase of testing includes exposure of coupons and components to caustic material at various temperatures for varying lengths of time. The coupons are manufactured from EPDM and Garlock{sup R} sheets and will be used to evaluate changes in material data from baseline data. Components (inner hoses, O-rings and gaskets) will also be used to determine the effects from an environment similar to its operational environment. The test loop utilizes a 25% NAOH solution as the fluid and can accommodate eighteen component assemblies, each consisting of one EPDM HIHTL, EPDM O-ring and Garlock{sup R} gasket. There are three assembly aging sets, one for each temperature (37.78 deg. C, 54.44 deg. C and 79.44 deg. C) and each set contains six assemblies; three for each of the two time periods (6 months and 1 year). Prior to aging, a sample set of the components had baseline mechanical properties tested and a sample set of the coupons had baseline material properties determined as per ASTM standards. After the aging is completed the mechanical and material properties of the aged samples will be measured and compared with the bass-line data to obtain an understanding of the synergistic effects of the two stressors. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Longevity of geo-synthetic cover components - 15450

Geo-synthetics form many of the key components in modern landfill cell and final cover designs. Models for the long-term performance assessment of systems incorporating these components have traditionally relied on a small number of standard assumptions originally developed to address the needs of the Resource Conservation and Recovery Act (RCRA) Subtitle D solid waste industry. These past estimates demonstrated that, even under a series of highly conservative factors, the longevity of these components far exceeds the requirements for typical solid waste facilities. Traditionally, the interpretation of the geo-synthetic degradation research has been deterministic as opposed to probabilistic, often due to the relative scarcity of degradation data for particular formulations and environmental conditions. Long-term studies of the mechanical and chemical properties of geo-synthetics subjected to accelerated aging processes have been conducted in an attempt to better quantify their longevity to address applications where performance may be required for 1,000 years or more. Of the many cover system geo-synthetic components, geo-membranes appear to have the most significant impact on the long-term performance of cover systems. Based on available long-term aging studies, a series of property degradation curves and their corresponding model parameters are available for geo-membranes. A strong area of need in the performance assessment of shallow disposal facilities is how to connect these research findings with inputs to probabilistic models. Significantly, factors affecting geo-membrane performance, such as geo-membrane thickness, anti-oxidant package, molecular weight, oxygen exposure, and drainage, can be adjusted and re-engineered using a proposed approach to meet specific performance targets. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Erosion and corrosion analysis of waste transfer components in the POR104 valve box at Hanford - 15715

At the United States Department of Energy Hanford Site in Richland, Washington, waste is being transferred to storage tanks in preparation for treatment at the Waste Treatment and Immobilization Plant. Regulatory committees have concerns regarding the structural integrity of the waste transfer components being used. Washington River Protection Solutions (WRPS) has employed a Fitness-for-Service program, which is a multi-disciplinary engineering approach that is used to determine if equipment is fit to remain in operation for a specified projected period. An approach to monitor aging equipment is to take thickness measurements of components when feasible, to evaluate if there is any appreciable degradation in the integrity of the components. The thickness measurements can be used to determine if erosion or corrosion is occurring and predict the remaining lifespan of the components. These predictions can also be used to develop design modifications for new piping and pipe jumpers. Analysis of thickness measurements have been conducted on four floor nozzles in the POR104 valve box located in the C-Tank Farm at Hanford. The data for the floor nozzles of the valve box does not show signs of wear, but there are variations in thicknesses which are likely due to manufacturing processes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Design and Construction of a Loess-Cement Cushion as an Integral Component of an SL-LILW Repository - 16077

The Bulgarian State Enterprise for Radioactive Waste Management (SERAW) is planning the construction of a near-surface repository for short-lived low and intermediate level radioactive waste, the National Disposal Facility (NDF), adjacent to the Kozloduy Nuclear Power Plant (KNPP). The NDF will be constructed as a reinforced concrete vault-type repository system, where prefabricated cubic waste packages (2 m on a side) will be emplaced in large reinforced concrete disposal cells. Waste emplacement operations will be conducted in three phases over a total of 60 years of operations. After the last waste packages have been disposed, an engineered multilayer cover will be installed over the site to further isolate the waste from the accessible environment. The Radiana Site where the NDF will be constructed is a sloping area located between the second and sixth loess terraces above the River Danube with elevations ranging from approximately +40 m to elevation +95 m. The unsaturated zone at the location selected for waste disposal ranges from 13 m to 16 m in thickness. After construction, the unsaturated zone will consist of a 5 m thick, engineered loess-cement cushion installed over naturally occurring Pliocene clays and sandy clayey sediments of the Brusarci Formation with a thickness above the top of groundwater ranging from 8 m to 11 m. The loess-cement cushion is a key component of the 'engineered fill' barrier as identified in the Intermediate Safety Assessment Report (ISAR) for the NDF. This barrier consists of engineered fill both below the disposal cells, i.e., the loess-cement cushion, and above the disposal cells, i.e. the final multilayer cover to be installed at closure of the facility. The loess-cement cushion component of this barrier will act to provide a geo-technically stable foundation for the disposal system. In addition, the barrier will raise the base of the disposal cells and increases the unsaturated zone thickness above the top of the groundwater table, as well as to serve as a chemical barrier that will act to sorb radionuclides thereby retarding their migration to the underlying groundwater. In addition to its assigned barrier functions the loess cement cushion also houses key embedded components required as part of the overall NDF safety concept, including systems necessary for operational and post-closure performance monitoring as well as the support foundation structures required for the mobile roofs, which are designed to handle and protect the waste during emplacement operations. The post-closure monitoring period, i.e., the period of institutional control, is given by as 300 years. While similar although less massive cushions have been previously constructed as foundations for various structures at the KNPP, the loess-cement cushion planned for construction at the NDF including the embedded structures will represent a first of its kind construction in terms of both its physical dimensioning as well as its requirements for long-term performance. This paper describes the design of the cushion, its functions and its construction as planned for the NDF as an integral component of the site safety concept. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Assessment of dynamic PRA techniques with industry average component performance data - 208

In the nuclear industry, risk monitors are intended to provide a point-in-time estimate of the system risk given the current plant configuration. Current risk monitors are limited in that they do not properly take into account the deteriorating states of plant equipment, which are unit-specific. Current approaches to computing risk monitors use probabilistic risk assessment (PRA) techniques, but the assessment is typically a snapshot in time. Living PRA models attempt to address limitations of traditional PRA models in a limited sense by including temporary changes in plant and system configurations. However, information on plant component condition is not considered. This often leaves risk monitors using living PRA models incapable of conducting evaluations with dynamic degradation scenarios evolving over time. There is a need to develop enabling approaches to solidify risk monitors to provide time- and condition-dependent risk by integrating traditional PRA models with condition monitoring and prognostic techniques. This paper presents an estimation of system risk evolution over time by integrating plant risk monitoring data with dynamic PRA methods that incorporate aging and degradation. Several online, nondestructive approaches have been developed for diagnosing plant component conditions in the nuclear industry, i.e., using a condition indication index, vibration analysis, current signatures, and operational history . In this work, the component performance measures at U.S. commercial nuclear power plants are incorporated within the dynamic PRA methodologies to provide better estimates of the probability of failures. Aging and degradation are modeled within the Level 1 PRA framework, are applied to several failure modes of pumps, and can be extended to a range of components, namely, valves, generators, batteries, and pipes. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Data analysis for valve leak detection of nuclear power plant safety critical components - 336

A nuclear plant consists of several safety-related components. These safety-related components are tested periodically in order to verify their functionality when they are called upon to perform. The data acquired during periodic testing provides information about possible degradation of the equipment or device under test. This research is focused on leak monitoring techniques to provide diagnostic information on the determination of valve aging and degradation. Several commercially available valve diagnostic-monitoring methods are evaluated, especially for the techniques based on measurements of acoustic emission, and accelerometer. The check valve is one of typical components being extensively used in safety systems of nuclear power plants. The failures of check valves have resulted in significant maintenance efforts, on occasion, have resulted in water hammer, over-pressurization of low-pressure systems, and damage to flow system components. In this paper, acoustic emission signals due to leak from check valves with artificial leakage and worn parts are investigated both analytically and experimentally. The results of advanced signal processing and de-noising techniques also have been identified. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Industry analytics to optimize time based maintenance for I and C components - 363

Using Industry Analytics to optimize time based maintenance for I and C components allows a nuclear site to increase cost efficiency without impacting equipment reliability. Reductions in frequency or deletions for non-value based Preventive Maintenance (PM) improves cost efficiency by decreasing man-hours, parts costs, and planning costs of that PM; while maintenance performed too frequently can induce maintenance related failures. Benchmarking Industry PM Performance and Equipment Failure data allows sites to efficiently optimize time based maintenance frequencies. Equipment Failure history identifies gaps in maintenance frequencies as well maintenance-induced failures. Overlapping the PM frequency from a site with Industry PM Performance identifies opportunities to justify cost savings by reducing the PM frequency. The opportunities are then validated by the site's living PM program to ensure that the site can support the extension. This paper will discuss an Industry analytical technique used for maintenance frequency reductions. The major aspects evaluated under the technique are validation of the Industry data, review of the component's history and comparison of additional information. Industry data from 180 sites is used as a benchmark to identify opportunities for PM frequency extension on like-for-like components based on manufacturer/model and application. The component history composed of preventive maintenance feedback history and corrective maintenance history is reviewed to determine if the frequency can be extended without adversely affecting equipment reliability. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Hydrogen Equipment Enclosure Risk Reduction through Earlier Detection of Component Failures

Hydrogen component reliability and the hazard associated with failure rates is a critical area of research for the successful implementation and growth of hydrogen technology across the globe. The research team has partnered to quantify system risk reduction through earlier detection of hydrogen component failures. A model of hydrogen dispersion in a hydrogen equipment enclosure has been developed utilizing experimentally quantified hydrogen component leak rates as inputs. This model provides insight into the impact of hydrogen safety sensors and ventilation on the flammable mass within a hydrogen equipment enclosure. This model also demonstrates the change in safety sensor response time due to detector placement under various leak scenarios. The team looks to improve overall hydrogen system safety through an improved understanding of hydrogen component reliability and risk mitigation methods. This collaboration fits under the work program of IEA Hydrogen Task 43 Subtask E Hydrogen System Safety.

CFD↗