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Thermocouples For High Temperature In-Pile Testing

Description: Many advanced nuclear reactor designs require new fuel, cladding and structural materials. Data are needed to characeterize the performance of these new materials in high temperature, oxidizing and radiation conditions. To obtain this data, robust instrumentation is needed htat can survive proposed test conditions. Traditional methods for measuring temperature in-pile degrade at temperatures above 1080 degrees C. Hence, a project was intiated to develop specialized thermocouples for high temperature in-pile applications (see Rempe and Wilkins, 2005). This paper summarizes efforts to develop, fabricate and evaluate these specialized thermocouples.
Date: November 1, 2005
Creator: Rempe, J. L.
Partner: UNT Libraries Government Documents Department

NHI Component Technical Readiness Evaluation System

Description: A decision process for evaluating the technical readiness or maturity of components (i.e., heat exchangers, chemical reactors, valves, etc.) for use by the U.S. DOE Nuclear Hydrogen Initiative is described. This system is used by the DOE NHI to assess individual components in relation to their readiness for pilot-scale and larger-scale deployment and to drive the research and development work needed to attain technical maturity. A description of the evaluation system is provided, and examples are given to illustrate how it is used to assist in component R&D decisions.
Date: September 1, 2007
Creator: Sherman, Steven R.; Wilson, Dane F. & Pawel, Steven J.
Partner: UNT Libraries Government Documents Department

High Temperature Thermocouples For In-pile Applications

Description: Traditional methods for measuring temperature in-pile degrade at temperatures above 1080 degrees C. Hence, a project has been initiated to explore the use of specialized thermocouples that are composed of materials that are able to withstand higher temperature, in-pile test conditions. Results from efforts to develop, fabricate and evaluate the performance of these specialized thermocouples are reported in this paper. Candidate materials were evaluated for their ability to withstand irradiation, to resit material interactions and to remain ductile at high temperatures. In addition, candidate thermocouples were evaluated based on their resolution over the temperature ranges of interest. Results from these evaluations are reported, and additional on-going development activities are summarized.
Date: October 1, 2005
Creator: Rempe, J. L. & Wilkins, S. C.
Partner: UNT Libraries Government Documents Department

Underground Corrosion After 32 Years: A Study of Fate and Transport - Annual Report, June 2004

Description: In 1970, the National Bureau of Standards (NBS), now call National Institute of Standards and Technology (NIST), implemented the most ambitious and comprehensive long-term corrosion behavior test to date for stainless steels in soil environments. Over 32 years have passed since scientists buried 6,324 specimens from stainless steel types, specialty alloys, composite configurations, and multiple material forms and treatment conditions at six distinctive soil-type sites throughout the country. At the start of this research project, more than 190 specimens per site, exceeding a total of 1000 specimens, remained undisturbed, a buried treasure of subsurface scientific data. This research project advocates the completion of the NIST corrosion study along with a thorough examination of the soil and environment surrounding the specimens. The project takes an interdisciplinary research approach that will correlate the complicated interrelationships among metal integrity, corrosion rates, corrosion mechanisms, soil properties, soil microbiology, plant and animal interaction with corrosion products, and fate and transport of metallic ions. The results will provide much-needed data on corrosion rates, underground material degradation, and the behavior of corrosion products in the near-field vadose zone. The data will improve the ability to predict the fate and transport of chemical and radiological contaminants at sites throughout the DOE complex. The research scope is focused on one of the six available sites, Site D, near Wildwood, NJ.
Date: June 1, 2004
Creator: Flitton, Kay Adler
Partner: UNT Libraries Government Documents Department

Atmospheric Pressure Plasma Process And Applications

Description: This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those produced in high intensity arcs, plasma torches, or in high intensity, high frequency discharges. Although nonthermal plasmas are at room temperatures, they are extremely effective in producing activated species, e.g., free radicals and excited state atoms. Thus, both thermal and nonthermal atmosphericpressure plasmas are finding applications in a wide variety of industrial processes, e.g. waste destruction, material recovery, extractive metallurgy, powder synthesis, and energy conversion. A brief discussion of recent plasma technology research and development activities at the Idaho National Laboratory is included.
Date: September 1, 2006
Creator: Kong, Peter C. & Myrtle
Partner: UNT Libraries Government Documents Department

Critical Heat Flux In Inclined Rectangular Narrow Long Channel

Description: In the TMI-2 accident, the lower part of the reactor pressure vessel had been overheated and then rather rapidly cooled down, as was later identified in a vessel investigation project. This accounted for the possibility of gap cooling feasibility. For this reason, several investigations were performed to determine the critical heat flux (CHF) from the standpoint of invessel retention. The experiments are conducted to investigate the general boiling phenomena, and the triggering mechanism for the CHF in a narrow gap using a 5 x 105 mm2 crevice type heater assembly and de-mineralized water. The test parameters include the gap size of 5 mm, and the surface orientation angles from the downward facing position (180o) to the vertical position (90o). The orientation angle affects the bubble layer and escape from the narrow gap. The CHF is less than that in a shorter channel, compared with the previous experiments having a heated length of 35 mmin the copper test section.
Date: May 1, 2005
Creator: Rempe, J. L.; Noh, S. W.; Kim, Y. H.; Suh, K. Y.; F.B.Cheung & Kim, S. B.
Partner: UNT Libraries Government Documents Department

Engineering Analysis of Intermediate Loop and Process Heat Exchanger Requirements to Include Configuration Analysis and Materials Needs

Description: The need to locate advanced hydrogen production facilities a finite distance away from a nuclear power source necessitates the need for an intermediate heat transport loop (IHTL). This IHTL must not only efficiently transport energy over distances up to 500 meters but must also be capable of operating at high temperatures (>850oC) for many years. High temperature, long term operation raises concerns of material strength, creep resistance and general material stability (corrosion resistance). IHTL design is currently in the initial stages. Many questions remain to be answered before intelligent design can begin. The report begins to look at some of the issues surrounding the main components of an IHTL. Specifically, a stress analysis of a compact heat exchanger design under expected operating conditions is reported. Also the results of a thermal analysis performed on two ITHL pipe configurations for different heat transport fluids are presented. The configurations consist of separate hot supply and cold return legs as well as annular design in which the hot fluid is carried in an inner pipe and the cold return fluids travels in the opposite direction in the annular space around the hot pipe. The effects of insulation configurations on pipe configuration performance are also reported. Finally, a simple analysis of two different process heat exchanger designs, one a tube in shell type and the other a compact or microchannel reactor are evaluated in light of catalyst requirements. Important insights into the critical areas of research and development are gained from these analyses, guiding the direction of future areas of research.
Date: September 1, 2005
Creator: Lillo, T.M.; Williamson, R.L.; Reed, T.R.; Davis, C.B. & Ginosar, D.M.
Partner: UNT Libraries Government Documents Department

Natural Convection Heat Transfer Experiment in a Hemispherical Pool

Description: Natural convection plays an important role in determining the thermal load from molten core accumulated in the reactor vessel lower head during a severe accident. Several numerical and experimental programs were conducted to study the heat transfer in the molten pool. Previous investigations were mostly related to the rectangular and semicircular pools. Except for COPO, UCLA, ACOPO, and BALI, previous investigations suffer from inadequate representation of high modified Rayleigh number (Ra') in the hemispherical pool that may be formed in the reactor core and lower plenum. Thus, experimental work is conducted utilizing SIGMA SP (Simulant Internal Gravitated Material Apparatus Spherical Pool) producing high Ra' turbulent natural convection in a hemispherical pool up to 5.3 x ~1011. The heating method has already been tested in SIGMA CP (Circular Pool). Six thin cable-type heaters, each with a diameter of 6 mm, are employed to simulate internal heating in the pool. They are uniformly distributed in the hemispherical pool to supply a maximum of 7.8 kW power to the pool. SIGMA SP has the inner and outer diameters of 500 mm and 520 mm, respectively. The upper flat plate and the curved wall of pool, with a 10 mm thick stainless steel plate, are cooled by a regulated water loop. A water-cooling system is used to maintain the temperature of water surrounding the test section nearly constant with time. This study focuses on quantifying the directional heat losses, angular heat flux distribution, and temperature distribution inside the molten pool.
Date: May 19, 2005
Creator: Rempe, J. L.; Lee, S. D.; Son, H. M.; Suh, K. Y.; F.B.Cheung & Kim, S. B.
Partner: UNT Libraries Government Documents Department