Science.gov

Sample records for initial coolant temperature

  1. Stagnation region gas film cooling: Effects of dimensionless coolant temperature

    NASA Technical Reports Server (NTRS)

    Bonnice, M. A.; Lecuyer, M. R.

    1983-01-01

    An experimental investigation was conducted to mode the film cooling performance for a turbine vane leading edge using the stagnation region of a cylinder in cross flow. Experiments were conducted with a single row of spanwise angled (25 deg) coolant holes for a range of the coolant blowing ratio and dimensionless coolant temperature with free stream-to-wall temperature ratio approximately 1.7 and Re sub D = 90000. the cylindrical test surface was instrumented with miniature heat flux gages and wall thermocouples to determine the percentage reduction in the Stanton number as a function of the distance downstream from injection (x/d sub 0) and the location between adjacent holes (z/S). Data from local heat flux measurements are presented for injection from a single row located at 5 deg, 22.9 deg, 40.8 deg, from stagnation using a hole spacing ratio of S/d = 5. The film coolant was injected with T sub c T sub w with a dimensionless coolant temperature in the range 1.18 or equal to theta sub c or equal to 1.56. The data for local Stanton Number Reduction (SNR) showed a significant increase in SNR as theta sub c was increased above 1.0.

  2. Analysis of a water-coolant leak into a very high-temperature vitrification chamber.

    SciTech Connect

    Felicione, F. S.

    1998-06-11

    A coolant-leakage incident occurred during non-radioactive operation of the Plasma Hearth Process waste-vitrification development system at Argonne National Laboratory when a stray electric arc ruptured az water-cooling jacket. Rapid evaporation of the coolant that entered the very high-temperature chamber pressurized the normally sub-atmospheric system above ambient pressure for over 13 minutes. Any positive pressurization, and particularly a lengthy one, is a safety concern since this can cause leakage of contaminants from the system. A model of the thermal phenomena that describe coolant/hot-material interactions was developed to better understand the characteristics of this type of incident. The model is described and results for a variety of hypothetical coolant-leak incidents are presented. It is shown that coolant leak rates above a certain threshold will cause coolant to accumulate in the chamber, and evaporation from this pool can maintain positive pressure in the system long after the leak has been stopped. Application of the model resulted in reasonably good agreement with the duration of the pressure measured during the incident. A closed-form analytic solution is shown to be applicable to the initial leak period in which the peak pressures are generated, and is presented and discussed.

  3. Turbine vane coolant flow variations and calculated effects on metal temperatures

    NASA Technical Reports Server (NTRS)

    Yeh, F. C.; Meitner, P. L.; Russell, L. M.

    1975-01-01

    Seventy-two air-cooled turbine vanes were tested to determine coolant flow variations among the vanes. Calculations were made to estimate the effect of measured coolant flow variations on local vane metal temperatures. The calculations were based on the following assumed operating conditions: turbine inlet temperature, 1700 K (2600 F); turbine inlet pressure, 31 N/sq cm (45 psia); coolant inlet temperature, 811 K (1000 F); and total coolant to gas flow ratio, 0.065. Variations of total coolant flow were not large (about 10 percent from the arithmetic mean) for all 72 vanes, but variations in local coolant flows were large. The local coolant flow variations ranged from 8 to 75 percent, and calculated metal temperature variations ranged from 8 to 60 K (15 to 180 F).

  4. Effect of Coolant Temperature and Mass Flow on Film Cooling of Turbine Blades

    NASA Technical Reports Server (NTRS)

    Garg, Vijay K.; Gaugler, Raymond E.

    1997-01-01

    A three-dimensional Navier Stokes code has been used to study the effect of coolant temperature, and coolant to mainstream mass flow ratio on the adiabatic effectiveness of a film-cooled turbine blade. The blade chosen is the VKI rotor with six rows of cooling holes including three rows on the shower head. The mainstream is akin to that under real engine conditions with stagnation temperature = 1900 K and stagnation pressure = 3 MPa. Generally, the adiabatic effectiveness is lower for a higher coolant temperature due to nonlinear effects via the compressibility of air. However, over the suction side of shower-head holes, the effectiveness is higher for a higher coolant temperature than that for a lower coolant temperature when the coolant to mainstream mass flow ratio is 5% or more. For a fixed coolant temperature, the effectiveness passes through a minima on the suction side of shower-head holes as the coolant to mainstream mass flow, ratio increases, while on the pressure side of shower-head holes, the effectiveness decreases with increase in coolant mass flow due to coolant jet lift-off. In all cases, the adiabatic effectiveness is highly three-dimensional.

  5. Measurement of the Coolant Channel Temperatures and Pressures of a Cooled Radial-Inflow Turbine

    NASA Technical Reports Server (NTRS)

    Dicicco, L. Danielle; Nowlin, Brent C.; Tirres, Lizet

    1994-01-01

    Instrumentation has been installed on the surface of a cooled radial-inflow turbine. Thermocouples and miniature integrated sensor pressure transducers were installed to measure steady state coolant temperatures, blade wall temperatures, and coolant pressures. These measurements will eventually be used to determine the heat transfer characteristics of the rotor. This paper will describe the procedures used to install and calibrate the instrumentation and the testing methods followed. A limited amount of data will compare the measured values to the predicted values.

  6. Method of and apparatus for removing silicon from a high temperature sodium coolant

    DOEpatents

    Yunker, Wayne H.; Christiansen, David W.

    1987-01-01

    A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

  7. Method of and apparatus for removing silicon from a high temperature sodium coolant

    DOEpatents

    Yunker, Wayne H.; Christiansen, David W.

    1987-05-05

    A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

  8. Coolant and ambient temperature control for chillerless liquid cooled data centers

    DOEpatents

    Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

    2016-02-02

    Cooling control methods include measuring a temperature of air provided to a plurality of nodes by an air-to-liquid heat exchanger, measuring a temperature of at least one component of the plurality of nodes and finding a maximum component temperature across all such nodes, comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold, and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the plurality of nodes based on the comparisons.

  9. Method of and apparatus for removing silicon from a high temperature sodium coolant

    DOEpatents

    Yunker, W.H.; Christiansen, D.W.

    1983-11-25

    This patent discloses a method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

  10. Effect of coolant flow ejection on aerodynamic performance of low-aspect-ratio vanes. 2: Performance with coolant flow ejection at temperature ratios up to 2

    NASA Technical Reports Server (NTRS)

    Hass, J. E.; Kofskey, M. G.

    1977-01-01

    The aerodynamic performance of a 0.5 aspect ratio turbine vane configuration with coolant flow ejection was experimentally determined in a full annular cascade. The vanes were tested at a nominal mean section ideal critical velocity ratio of 0.890 over a range of primary to coolant total temperature ratio from 1.0 to 2.08 and a range of coolant to primary total pressure ratio from 1.0 to 1.4 which corresponded to coolant flows from 3.0 to 10.7 percent of the primary flow. The variations in primary and thermodynamic efficiency and exit flow conditions with circumferential and radial position were obtained.

  11. Effects of coolant parameters on steady state temperature distribution in phospheric-acid fuel cell electrode

    NASA Technical Reports Server (NTRS)

    Alkasab, K. A.; Abdul-Aziz, A.

    1991-01-01

    The influence of thermophysical properties and flow rate on the steady-state temperature distribution in a phosphoric-acid fuel cell electrode plate was experimentally investigated. An experimental setup that simulates the operating conditions prevailing in a phosphoric-acid fuel cell stack was used. The fuel cell cooling system utilized three types of coolants to remove excess heat generated in the cell electrode and to maintain a reasonably uniform temperature distribution in the electrode plate. The coolants used were water, engine oil, and air. These coolants were circulated at Reynolds number ranging from 1165 to 6165 for water; 3070 to 6864 for air; and 15 to 79 for oil. Experimental results are presented.

  12. In-core coolant flow monitoring of pressurized water reactors using temperature and neutron noise

    SciTech Connect

    Sweeney, F.J.; Upadhyaya, B.R.; Shieh, D.J.

    1984-01-01

    Noise measurements were performed at the Loss-of-Fluid-Test (LOFT) and Sequoyah-1 pressurized water reactors (PWRs) in order to investigate the possibility of inferring in-core coolant velocities from cross-power spectral density (CPSD) phases of core-exit thermocouple and in-core neutron detector signals. These noise measurements were used to investigate the effects of inlet coolant temperature, core flow, reactor power, and random heat transfer fluctuations on the noise-inferred coolant velocities. The effect on the inferred velocities of varying in-core neutron detector and core-exit thermocouple locations was also investigated. Theoretical models of temperature noise were developed, and the results were used to interpret the experimental measurements. Results of these studies indicate that the neutron detector/thermocouple phase is useful for monitoring core flow in PWRs. Results show that the interpretation of the phase between these signals depends on the source of temperature noise, the response times and locations of the sensors, and the neutron dynamics of the reactor. At Sequoyah-1 we found that the in-core neutron detector/core-exit thermocouple phase can be used to infer in-core coolant velocities, provided that the measurements are corrected for the thermocouple response time.

  13. Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles

    SciTech Connect

    Hsu, J.S.; Staunton, M.R.; Starke, M.R.

    2006-09-30

    This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from test data at

  14. Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles

    SciTech Connect

    Staunton, Robert H; Hsu, John S; Starke, Michael R

    2006-09-01

    This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from test data at

  15. Cooling Characteristics of the V-1650-7 Engine. II - Effect of Coolant Conditions on Cylinder Temperatures and Heat Rejection at Several Engine Powers

    NASA Technical Reports Server (NTRS)

    Povolny, John H.; Bogdan, Louis J.; Chelko, Louis J.

    1947-01-01

    An investigation has been conducted on a V-1650-7 engine to determine the cylinder temperatures and the coolant and oil heat rejections over a range of coolant flows (50 to 200 gal/min) and oil inlet temperatures (160 to 2150 F) for two values of coolant outlet temperature (250 deg and 275 F) at each of four power conditions ranging from approximately 1100 to 2000 brake horsepower. Data were obtained for several values of block-outlet pressure at each of the two coolant outlet temperatures. A mixture of 30 percent by volume of ethylene glycol and 70-percent water was used as the coolant. The effect of varying coolant flow, coolant outlet temperature, and coolant outlet pressure over the ranges investigated on cylinder-head temperatures was small (0 deg to 25 F) whereas the effect of increasing the engine power condition from ll00 to 2000 brake horsepower was large (maximum head-temperature increase, 110 F).

  16. Cooled-turbine aerodynamic performance prediction from reduced primary to coolant total-temperature-ratio results

    NASA Technical Reports Server (NTRS)

    Goldman, L. J.

    1976-01-01

    The prediction of the cooled aerodynamic performance, for both stators and turbines, at actual primary to coolant inlet total temperature ratios from the results obtained at a reduced total temperature ratio is described. Theoretical and available experimental results were compared for convection film and transpiration cooled stator vanes and for a film cooled, single stage core turbine. For these tests the total temperature ratio varied from near 1.0 to about 2.7. The agreement between the theoretical and the experimental results was, in general, reasonable.

  17. The high-temperature sodium coolant technology in nuclear power installations for hydrogen power engineering

    NASA Astrophysics Data System (ADS)

    Kozlov, F. A.; Sorokin, A. P.; Alekseev, V. V.; Konovalov, M. A.

    2014-05-01

    In the case of using high-temperature sodium-cooled nuclear power installations for obtaining hydrogen and for other innovative applications (gasification and fluidization of coal, deep petroleum refining, conversion of biomass into liquid fuel, in the chemical industry, metallurgy, food industry, etc.), the sources of hydrogen that enters from the reactor plant tertiary coolant circuit into its secondary coolant circuit have intensity two or three orders of magnitude higher than that of hydrogen sources at a nuclear power plant (NPP) equipped with a BN-600 reactor. Fundamentally new process solutions are proposed for such conditions. The main prerequisite for implementing them is that the hydrogen concentration in sodium coolant is a factor of 100-1000 higher than it is in modern NPPs taken in combination with removal of hydrogen from sodium by subjecting it to vacuum through membranes made of vanadium or niobium. Numerical investigations carried out using a diffusion model showed that, by varying such parameters as fuel rod cladding material, its thickness, and time of operation in developing the fuel rods for high-temperature nuclear power installations (HT NPIs) it is possible to exclude ingress of cesium into sodium through the sealed fuel rod cladding. However, if the fuel rod cladding loses its tightness, operation of the HT NPI with cesium in the sodium will be unavoidable. Under such conditions, measures must be taken for deeply purifying sodium from cesium in order to minimize the diffusion of cesium into the structural materials.

  18. Distributed Raman temperature measurement system for monitoring of nuclear power plant coolant loops

    NASA Astrophysics Data System (ADS)

    Jensen, Fredrik B. H.; Takada, Eiji; Nakazawa, Masaharu; Kakuta, Tsunemi; Yamamoto, Satoshi

    1996-09-01

    A distributed temperature sensor based on Raman scattering in optical fibers has been tested for use as coolant loop monitor in nuclear power plants. Different types of pure- silica-core, polyimide-coated fibers have been subjected to 60Co-gamma-ray and fission-reactor irradiation at varying temperatures. 60Co-gamma-ray irradiations at dose rates from 4.8 kR/h up to 1 MR/h were done. Simultaneous gamma-ray and high temperature experiments up to 300 degrees Celsius have also been performed. The induced loss of the tested fibers was found to saturate with increasing dose at the anti-Stokes and Stokes wavelengths. This feature was then made use of to develop a model for radiation induced loss which was used to make system lifetime predictions. It has also been demonstrated that the induced loss of the optical fibers is favorably affected by high-temperature use. A 10-fold decrease in the radiation- induced loss levels when the system was operated at 300 degrees Celsius was observed, as compared with room- temperature operation. The experiments have shown that with a pure-silica-core, polyimide-coated fiber the temperature sensing capabilities of the RDTS will not be degraded excessively if used at primary coolant loops with an expected upper radiation level of 200 R/hr.

  19. Corrosion of Ferritic Steels in High Temperature Molten Salt Coolants for Nuclear Applications

    SciTech Connect

    Farmer, J; El-Dasher, B; de Caro, M S; Ferreira, J

    2008-11-25

    Corrosion of ferritic steels in high temperature molten fluoride salts may limit the life of advanced reactors, including some hybrid systems that are now under consideration. In some cases, the steel may be protected through galvanic coupling with other less noble materials with special neutronic properties such a beryllium. This paper reports the development of a model for predicting corrosion rates for various ferritic steels, with and without oxide dispersion strengthening, in FLiBe (Li{sub 2}BeF{sub 4}) and FLiNaK (Li-Na-K-F) coolants at temperatures up to 800 C. Mixed potential theory is used to account for the protection of steel by beryllium, Tafel kinetics are used to predict rates of dissolution as a function of temperature and potential, and the thinning of the mass-transfer boundary layer with increasing Reynolds number is accounted for with dimensionless correlations. The model also accounts for the deceleration of corrosion as the coolants become saturated with dissolved chromium and iron. This paper also reports electrochemical impedance spectroscopy of steels at their corrosion potentials in high-temperature molten salt environments, with the complex impedance spectra interpreted in terms of the interfacial charge transfer resistance and capacitance, as well as the electrolyte conductivity. Such in situ measurement techniques provide valuable insight into the degradation of materials under realistic conditions.

  20. Measurement of core coolant flow velocities in PWRs using temperature: neutron noise cross correlation

    SciTech Connect

    Sweeney, F.J.; Upadhyaya, B.R.

    1982-01-01

    To study the relationship between the time delay inferred from this phase angle and core coolant flow velocities, noise measurements were performed at the Loss of Fluid Test Facility (LOFT) reactor and at a commercial PWR. In-core, self-powered neutron detector (SPND) noise at LOFT and ex-core ionization chamber noise at the commercial PWR were cross correlated with core exit temperature noise. Time delays were inferred from the slope of the phase angle versus frequency plots over the frequency range from 0.05 to 2.0 Hz.

  1. Assessment of Candidate Molten Salt Coolants for the Advanced High Temperature Reactor (AHTR)

    SciTech Connect

    Williams, D.F.

    2006-03-24

    The Advanced High-Temperature Reactor (AHTR) is a novel reactor design that utilizes the graphite-matrix high-temperature fuel of helium-cooled reactors, but provides cooling with a high-temperature fluoride salt. For applications at temperatures greater than 900 C the AHTR is also referred to as a Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR). This report provides an assessment of candidate salts proposed as the primary coolant for the AHTR based upon a review of physical properties, nuclear properties, and chemical factors. The physical properties most relevant for coolant service were reviewed. Key chemical factors that influence material compatibility were also analyzed for the purpose of screening salt candidates. Some simple screening factors related to the nuclear properties of salts were also developed. The moderating ratio and neutron-absorption cross-section were compiled for each salt. The short-lived activation products, long-lived transmutation activity, and reactivity coefficients associated with various salt candidates were estimated using a computational model. Table A presents a summary of the properties of the candidate coolant salts. Certain factors in this table, such as melting point, vapor pressure, and nuclear properties, can be viewed as stand-alone parameters for screening candidates. Heat-transfer properties are considered as a group in Sect. 3 in order to evaluate the combined effects of various factors. In the course of this review, it became apparent that the state of the properties database was strong in some areas and weak in others. A qualitative map of the state of the database and predictive capabilities is given in Table B. It is apparent that the property of thermal conductivity has the greatest uncertainty and is the most difficult to measure. The database, with respect to heat capacity, can be improved with modern instruments and modest effort. In general, ''lighter'' (low-Z) salts tend to exhibit better heat

  2. Self-actuated nuclear reactor shutdown system using induction pump to facilitate sensing of core coolant temperature

    DOEpatents

    Sievers, Robert K.; Cooper, Martin H.; Tupper, Robert B.

    1987-01-01

    A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes. The latching mechanism has an inner flow passage extending between and in flow communication with the absorber bundles and the inner flow channel of the top nozzle for accommodating primary coolant flow upwardly through the control assembly. Also, an outer flow passage separate from the inner flow passage extends through the latching mechanism between and in flow communication with the inner duct and the outer flow channel of the top nozzle for accommodating inflow of a portion of the heated coolant from the adjacent fuel assemblies. The latching mechanism contains a magnetic material sensitive to temperature and operable to cause mating or latching together of the components of the latching mechanism when the temperature sensed is below a known temperature and unmating or unlatching thereof when the temperature sensed is above a given temperature. The temperature sensitive magnetic material is positioned in communication with the heated coolant flow through the outer flow passage for directly sensing the temperature thereof. Finally, the pumping means includes a jet induction pump nozzle and diffuser disposed adjacent the bottom nozzle of the control assembly

  3. The international surface temperature initiative

    NASA Astrophysics Data System (ADS)

    Thorne, P. W.; Lawrimore, J. H.; Willett, K. M.; Allan, R.; Chandler, R. E.; Mhanda, A.; de Podesta, M.; Possolo, A.; Revadekar, J.; Rusticucci, M.; Stott, P. A.; Strouse, G. F.; Trewin, B.; Wang, X. L.; Yatagai, A.; Merchant, C.; Merlone, A.; Peterson, T. C.; Scott, E. M.

    2013-09-01

    The aim of International Surface Temperature Initiative is to create an end-to-end process for analysis of air temperature data taken over the land surface of the Earth. The foundation of any analysis is the source data. Land surface air temperature records have traditionally been stored in local, organizational, national and international holdings, some of which have been available digitally but many of which are available solely on paper or as imaged files. Further, economic and geopolitical realities have often precluded open sharing of these data. The necessary first step therefore is to collate readily available holdings and augment these over time either through gaining access to previously unavailable digital data or through data rescue and digitization activities. Next, it must be recognized that these historical measurements were made primarily in support of real-time weather applications where timeliness and coverage are key. At almost every long-term station it is virtually certain that changes in instrumentation, siting or observing practices have occurred. Because none of the historical measures were made in a metrologically traceable manner there is no unambiguous way to retrieve the true climate evolution from the heterogeneous raw data holdings. Therefore it is desirable for multiple independent groups to produce adjusted data sets (so-called homogenized data) to adequately understand the data characteristics and estimate uncertainties. Then it is necessary to benchmark the performance of the contributed algorithms (equivalent to metrological software validation) through development of realistic benchmark datasets. In support of this, a series of successive benchmarking and assessment cycles are envisaged, allowing continual improvement while avoiding over-tuning of algorithms. Finally, a portal is proposed giving access to related data-products, utilizing the assessment results to provide guidance to end-users on which product is the most suited to

  4. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, C.W.

    1994-11-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.

  5. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, Charles W.

    1994-01-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

  6. UO2 and PuO2 utilization in high temperature engineering test reactor with helium coolant

    NASA Astrophysics Data System (ADS)

    Waris, Abdul; Aji, Indarta K.; Novitrian, Pramuditya, Syeilendra; Su'ud, Zaki

    2016-03-01

    High temperature engineering test reactor (HTTR) is one of high temperature gas cooled reactor (HTGR) types which has been developed by Japanese Atomic Energy Research Institute (JAERI). The HTTR is a graphite moderator, helium gas coolant, 30 MW thermal output and 950 °C outlet coolant temperature for high temperature test operation. Original HTTR uses UO2 fuel. In this study, we have evaluated the use of UO2 and PuO2 in form of mixed oxide (MOX) fuel in HTTR. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. The result shows that HTTR can obtain its criticality condition if the enrichment of 235U in loaded fuel is 18.0% or above.

  7. JAEA Studies on High Burnup Fuel Behaviors during Reactivity-Initiated Accident and Loss-of-Coolant Accident

    SciTech Connect

    Fuketa, Toyoshi; Sugiyama, Tomoyuki; Nagase, Fumihisa; Suzuki, Motoe

    2007-07-01

    The objectives of fuel safety research program at Japan Atomic Energy Agency (JAEA) are; to evaluate adequacy of present safety criteria and safety margins; to provide a database for future regulation on higher burnup UO{sub 2} and MOX fuels, new cladding and pellets; and to provide reasonably mechanistic computer codes for regulatory application. The JAEA program is comprised of reactivity-initiated accident (RIA) studies including pulse-irradiation experiments in the NSRR and cladding mechanical tests, loss-of-coolant accident (LOCA) tests including integral thermal shock test and oxidation rate measurement, development and verification of computer codes FEMAXI-6 and RANNS, and so on. In addition to an overview of the fuel safety research at JAEA, most recent progresses in the RIA and LOCA tests programs and the codes development are described and discussed in the paper. (authors)

  8. Development of a coolant channel helium and nitrogen gas ratio sensor for a high temperature gas reactor

    SciTech Connect

    Cadell, S. R.; Woods, B. G.

    2012-07-01

    To measure the changing gas composition of the coolant during a postulated High Temperature Gas Reactor (HTGR) accident, an instrument is needed. This instrument must be compact enough to measure the ratio of the coolant versus the break gas in an individual coolant channel. This instrument must minimally impact the fluid flow and provide for non-direct signal routing to allow minimal disturbance to adjacent channels. The instrument must have a flexible geometry to allow for the measurement of larger volumes such as in the upper or lower plenum of a HTGR. The instrument must be capable of accurately functioning through the full operating temperature and pressure of a HTGR. This instrument is not commercially available, but a literature survey has shown that building off of the present work on Capacitance Sensors and Cross-Capacitors will provide a basis for the development of the desired instrument. One difficulty in developing and instrument to operate at HTGR temperatures is acquiring an electrical conductor that will not melt at 1600 deg. C. This requirement limits the material selection to high temperature ceramics, graphite, and exotic metals. An additional concern for the instrument is properly accounting for the thermal expansion of both the sensing components and the gas being measured. This work covers the basic instrument overview with a thorough discussion of the associated uncertainty in making these measurements. (authors)

  9. Analysis of metal temperature and coolant flow with a thermal-barrier coating on a full-coverage-film-cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.

    1978-01-01

    The potential benefits of combining full-coverage film cooling with a thermal-barrier coating were investigated analytically for sections on the suction and pressure sides a high-temperature, high-pressure turbine vane. Metal and ceramic coating temperatures were calculated as a function of coating thickness and coolant flow. With a thermal-barrier coating, the coolant flows required for the chosen sections were half those of an uncoated design, and the metal outer temperatures were simultaneously reduced by over 111 K (200 F). For comparison, transpiration cooling was also investigated. Full-coverage film cooling of a coated vane required more coolant flow than did transpiration cooling.

  10. Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement

    NASA Technical Reports Server (NTRS)

    Lundin, Bruce T; Povolny, John H; Chelko, Louis J

    1949-01-01

    Data obtained from an extensive investigation of the cooling characteristics of four multicylinder, liquid-cooled engines have been analyzed and a correlation of both the cylinder-head temperatures and the coolant heat rejections with the primary engine and coolant variables was obtained. The method of correlation was previously developed by the NACA from an analysis of the cooling processes involved in a liquid-cooled-engine cylinder and is based on the theory of nonboiling, forced-convection heat transfer. The data correlated included engine power outputs from 275 to 1860 brake horsepower; coolant flows from 50 to 320 gallons per minute; coolants varying in composition from 100 percent water to 97 percent ethylene glycol and 3 percent water; and ranges of engine speed, manifold pressure, carburetor-air temperature, fuel-air ratio, exhaust-gas pressure, ignition timing, and coolant temperature. The effect on engine cooling of scale formation on the coolant passages of the engine and of boiling of the coolant under various operating conditions is also discussed.

  11. Comparison of Calculated and Experimental Temperatures and Coolant Pressure Losses for a Cascade of Small Air-Cooled Turbine Rotor Blades

    NASA Technical Reports Server (NTRS)

    Stepka, Francis S

    1958-01-01

    Average spanwise blade temperatures and cooling-air pressure losses through a small (1.4-in, span, 0.7-in, chord) air-cooled turbine blade were calculated and are compared with experimental nonrotating cascade data. Two methods of calculating the blade spanwise metal temperature distributions are presented. The method which considered the effect of the length-to-diameter ratio of the coolant passage on the blade-to-coolant heat-transfer coefficient and assumed constant coolant properties based on the coolant bulk temperature gave the best agreement with experimental data. The agreement obtained was within 3 percent at the midspan and tip regions of the blade. At the root region of the blade, the agreement was within 3 percent for coolant flows within the turbulent flow regime and within 10 percent for coolant flows in the laminar regime. The calculated and measured cooling-air pressure losses through the blade agreed within 5 percent. Calculated spanwise blade temperatures for assumed turboprop engine operating conditions of 2000 F turbine-inlet gas temperature and flight conditions of 300 knots at a 30,000-foot altitude agreed well with those obtained by the extrapolation of correlated experimental data of a static cascade investigation of these blades.

  12. Assessment of a large break loss of coolant accident scenario requiring operator action to initiate safety injection

    SciTech Connect

    Grendys, R.C.; Nissley, M.E.; Baker, D.C.

    1996-11-01

    As part of the licensing basis for a nuclear power plant, the acceptability of the Emergency Core Cooling Systems (ECCS) following a postulated Loss-of-Coolant Accident (LOCA) as described in the Code of Federal Regulations (CFR), Title 10, Chapter 1, Part 50.46, must be verified. The LOCA analysis is performed with an acceptable ECCS Evaluation Model and results must show compliance with the 10 CFR 50.46 acceptance criteria. Westinghouse Electric Corporation performs Large and Small Break LOCA and LOCA-related analyses to support the licensing basis of various nuclear power plants and also performs evaluations against the licensing basis analyses as required. Occasionally, the need arises for the holder of an operating license of a nuclear power plant to submit a Licensee Event Report (LER) to the US Nuclear Regulatory Commission (USNRC) for any event of the type described in the Code of Federal Regulations, Title 10, Chapter 1, Part 50.73. To support the LER, a Justification for Past Operation (JPO) may be performed to assess the safety consequences and implications of the event based on previous operating conditions. This paper describes the work performed for the Large Break LOCA to assess the impact of an event discovered by Florida Power and Light and reported in LER-94-005-02. For this event, it was determined that under certain circumstances, operator action would have been required to initiate safety injection (SI), thus challenging the acceptability of the ECCS. This event was specifically addressed for the Large Break LOCA by using an advanced thermal hydraulic analysis methodology with realistic input assumptions.

  13. Steam as turbine blade coolant: Experimental data generation

    SciTech Connect

    Wilmsen, B.; Engeda, A.; Lloyd, J.R.

    1995-10-01

    Steam as a coolant is a possible option to cool blades in high temperature gas turbines. However, to quantify steam as a coolant, there exists practically no experimental data. This work deals with an attempt to generate such data and with the design of an experimental setup used for the purpose. Initially, in order to guide the direction of experiments, a preliminary theoretical and empirical prediction of the expected experimental data is performed and is presented here. This initial analysis also compares the coolant properties of steam and air.

  14. FORTRAN program for calculating coolant flow and metal temperatures of a full-coverage-film-cooled vane or blade

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.

    1978-01-01

    A computer program that calculates the coolant flow and the metal temperatures of a full-coverage-film-cooled vane or blade was developed. The analysis was based on compressible, one-dimensional fluid flow and on one-dimensional heat transfer and treats the vane or blade shell as a porous wall. The calculated temperatures are average values for the shell outer-surface area associated with each film-cooling hole row. A thermal-barrier coating may be specified on the shell outer surface, and centrifugal effects can be included for blade calculations. The program is written in FORTRAN 4 and is operational on a UNIVAC 1100/42 computer. The method of analysis, the program input, the program output, and two sample problems are provided.

  15. Shock Initiation of Energetic Materials at Different Initial Temperatures

    SciTech Connect

    Urtiew, P A; Tarver, C M

    2005-01-14

    Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 (92.5 % triaminotrinitrobenzene (TATB) with 7.5 % Kel-F binder) and LX-04 (85 % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15 % Viton binder) at several initial temperatures.

  16. Metal temperatures and coolant flow in a wire cloth transpiration cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Gladden, H. J.

    1975-01-01

    An experimental heat transfer investigation was conducted on an air-cooled turbine vane made from wire-wound cloth material and supported by a central strut. Vane temperature data obtained are compared with temperature data from two full-coverage film-cooled vanes made of different laminated construction. Measured porous-airfoil temperatures are compared with predicted temperatures.

  17. Cooling Characteristics of the V-1650-7 Engine. 1; Coolant-Flow Distribution, Cylinder Temperatures, and Heat Rejections at Typical Operating Conditions

    NASA Technical Reports Server (NTRS)

    Povolny, John H.; Bogdan, Louis J.

    1947-01-01

    An investigation was conducted to determine the coolant-flow distribu tion, the cylinder temperatures, and the heat rejections of the V-165 0-7 engine . The tests were run a t several power levels varying from minimum fuel consumption to war emergency power and at each power l evel the coolant flows corresponded to the extremes of those likely t o be encountered in typical airplane installations, A mixture of 30-p ercent ethylene glycol and 70-percent water was used as the coolant. The temperature of each cylinder was measured between the exhaust val ves, between the intake valves, in the center of the head, on the exh aust-valve guide, at the top of the barrel on the exhaust side, and o n each exhaust spark-plug gasket. For an increase in engine power fro m 628 to approximately 1700 brake horsepower the average temperature for the cylinder heads between the exhaust valves increased from 437 deg to 517 deg F, the engine coolant heat rejection increased from 12 ,600 to 22,700 Btu. per minute, the oil heat rejection increased from 1030 to 4600 Btu per minute, and the aftercooler-coolant heat reject ion increased from 450 to 3500 Btu -per minute.

  18. Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems

    SciTech Connect

    Meisner, Gregory P

    2013-10-08

    Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

  19. Hepatic radiofrequency ablation with internally cooled probes: effect of coolant temperature on lesion size.

    PubMed

    Haemmerich, Dieter; Chachati, Louay; Wright, Andrew S; Mahvi, David M; Lee, Fred T; Webster, John G

    2003-04-01

    Radiofrequency (RF) ablation is a minimally invasive method for treatment of primary and metastatic liver tumors. One of the currently commercially available devices employs an internally cooled 17-gauge needle probe. Within the probe, cool water is circulated during ablation, which cools tissue close to the probe resulting in larger lesions. We evaluated the effect of different cooling water temperatures on lesion size. We created a finite-element method model, simulated 12 min impedance-controlled ablation and determined temperature distribution for three water temperatures. Lesion diameters in the model were 33.8, 33.4, and 32.8 mm for water temperatures of 5 degrees C, 15 degrees C, and 25 degrees C, respectively. We solved a simplified model geometry analytically and present dependence of lesion diameter on cooling temperature. We further performed ex vivo experiments in fresh bovine liver. We created four lesions for each water temperature, with the same water temperatures as used in the finite-element method (FEM) model. Average lesion diameters were 28.3, 30, and 29.5 mm for water temperatures of 5 degrees C, 15 degrees C, and 25 degrees C, respectively. Water temperature did not have a significant effect on lesion size in the ex vivo experiments (p = 0.76), the FEM model, and the analytical solution. PMID:12723061

  20. The Effect of Saline Coolant on Temperature Levels during Decortication with a Midas Rex: An in Vitro Model Using Sheep Cervical Vertebrae.

    PubMed

    Livingston, Asher; Wang, Tian; Christou, Chris; Pelletier, Matthew H; Walsh, William R

    2015-01-01

    Decortication of bone with a high-speed burr in the absence of coolant may lead to local thermal necrosis and decreased healing ability, which may negatively impact clinical outcome. Little data are available on the impact of applying a coolant during the burring process. This study aims to establish an in vitro model to quantitatively assess peak temperatures during endplate preparation with a high-speed burr. Six sheep cervical vertebrae were dissected and mounted. Both end plates were used to give a total of 12 sites. Two thermocouples were inserted into each vertebra, 2 mm below the end plate surface and a thermal camera set up to measure surface temperature. A 3 mm high-pneumatic speed burr (Midas Rex, Medtronic, Fort Worth, TX, USA) was used to decorticate the bone in a side to side sweeping pattern, using a matchstick burr (M-8/9MH30) with light pressure. This procedure was repeated while dripping saline onto the burr and bone. Data were compared between groups using a Student's t-test. Application of coolant at the bone-burr interface during decortication resulted in a significant decrease in final temperature. Without coolant, maximum temperatures 2 mm from the surface were not sufficient to cause thermal osteonecrosis, although peak surface temperatures would cause local damage. The use of a high-speed burr provides a quick and an effective method of vertebral end plate preparation. Thermal damage to the bone can be minimized through the use of light pressure and saline coolant. This has implications for any bone preparation performed with a high-speed burr. PMID:26284253

  1. The Effect of Saline Coolant on Temperature Levels during Decortication with a Midas Rex: An in Vitro Model Using Sheep Cervical Vertebrae

    PubMed Central

    Livingston, Asher; Wang, Tian; Christou, Chris; Pelletier, Matthew H.; Walsh, William R.

    2015-01-01

    Decortication of bone with a high-speed burr in the absence of coolant may lead to local thermal necrosis and decreased healing ability, which may negatively impact clinical outcome. Little data are available on the impact of applying a coolant during the burring process. This study aims to establish an in vitro model to quantitatively assess peak temperatures during endplate preparation with a high-speed burr. Six sheep cervical vertebrae were dissected and mounted. Both end plates were used to give a total of 12 sites. Two thermocouples were inserted into each vertebra, 2 mm below the end plate surface and a thermal camera set up to measure surface temperature. A 3 mm high-pneumatic speed burr (Midas Rex, Medtronic, Fort Worth, TX, USA) was used to decorticate the bone in a side to side sweeping pattern, using a matchstick burr (M-8/9MH30) with light pressure. This procedure was repeated while dripping saline onto the burr and bone. Data were compared between groups using a Student’s t-test. Application of coolant at the bone–burr interface during decortication resulted in a significant decrease in final temperature. Without coolant, maximum temperatures 2 mm from the surface were not sufficient to cause thermal osteonecrosis, although peak surface temperatures would cause local damage. The use of a high-speed burr provides a quick and an effective method of vertebral end plate preparation. Thermal damage to the bone can be minimized through the use of light pressure and saline coolant. This has implications for any bone preparation performed with a high-speed burr. PMID:26284253

  2. A fracture mechanics approach for estimating fatigue crack initiation in carbon and low-alloy steels in LWR coolant environments

    SciTech Connect

    Park, H. B.; Chopra, O. K.

    2000-04-10

    A fracture mechanics approach for elastic-plastic materials has been used to evaluate the effects of light water reactor (LWR) coolant environments on the fatigue lives of carbon and low-alloy steels. The fatigue life of such steel, defined as the number of cycles required to form an engineering-size crack, i.e., 3-mm deep, is considered to be composed of the growth of (a) microstructurally small cracks and (b) mechanically small cracks. The growth of the latter was characterized in terms of {Delta}J and crack growth rate (da/dN) data in air and LWR environments; in water, the growth rates from long crack tests had to be decreased to match the rates from fatigue S-N data. The growth of microstructurally small cracks was expressed by a modified Hobson relationship in air and by a slip dissolution/oxidation model in water. The crack length for transition from a microstructurally small crack to a mechanically small crack was based on studies on small crack growth. The estimated fatigue S-N curves show good agreement with the experimental data for these steels in air and water environments. At low strain amplitudes, the predicted lives in water can be significantly lower than the experimental values.

  3. Coolant line hydrometer

    SciTech Connect

    Barber, M.D.; Kipp, W.G.

    1987-03-17

    This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein individually as a function of the specific gravity of the coolant. The coolant receiving chamber means includes a closure cap which when connected to the tubular fitting forms a coolant receiving chamber, retaining means for retaining the indicating float elements within the coolant receiving chamber, a viewing window member of a substantially clear material through which the float elements can be visually observed within the coolant receiving chamber means, and air venturi means located within the coolant receiving chamber means for automatically removing air which may collect within the coolant chamber means.

  4. In-core coolant velocity measurements in a pressurized water reactor using temperature-neutron noise cross correlation

    SciTech Connect

    Sweeney, F.J.

    1984-01-01

    Noise signals from an in-core, movable, neutron flux-mapping detector and a core-exit thermocouple at the Sequoyah-1 plant were cross correlated in order to investigate the feasibility of inferring in-core coolant flow velocities. If feasible, this technique might provide a cost effective way to detect local in-core flow blockages or to verify fuel assembly thermal-hydraulic performance. Previous ex-core neutron detector/core-exit thermocouple cross correlations at Sequoyah-1, indicated that, while coolant velocity measurements appeared to be feasible, the inferred velocities required correction for the relatively slow (approx.0.7-s) thermocouple time response. Furthermore, the effect on the inferred velocity due to the spatial averaging of the 1.8-m-long ex-core detector was not known. Noise measurements were therefore performed using a smaller neutron detector (0.48-cm diam by 5.33-cm long fission chamber), and a technique was developed to correct the inferred coolant velocities for the thermocouple response time.

  5. Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core

    SciTech Connect

    Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M.

    2012-07-01

    The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

  6. Preliminary Study on Utilization of Carbon Dioxide as a Coolant of High Temperature Engineering Test Reactor with MOX and Minor Actinides Fuel

    SciTech Connect

    Fauzia, A. F.; Waris, A.; Novitrian

    2010-06-22

    High temperature engineering test reactor (HTTR) is an uranium oxide (UO2) fuel, graphite moderator and helium gas-cooled reactor with 30 MW in thermal output and outlet coolant temperature of 950 deg. C. Instead of using helium gas, we have utilized carbon dioxide as a coolant in the present study. Beside that, uranium and plutonium oxide (mixed oxide, MOX) and minor actinides have been employed as a new fuel type of HTTR. Utilization of plutonium and minor actinide is one of the support system to non-proliferation issue in the nuclear development. The enrichment for uranium oxide has been varied of 6-20% with plutonium and minor actinides concentration of 10%. In this study, burnup period is 1100 days. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. Reactor core calculation was done by using CITATION module. The result shows that HTTR can achieve its criticality condition with 14% of {sup 235}U enrichment.

  7. Measuring flow and pressure of lithium coolant under developmental testing of a high-temperature cooling system of a space nuclear power plant

    NASA Astrophysics Data System (ADS)

    Sobolev, V. Ya.; Sinyavsky, V. V.

    2014-12-01

    Sub-megawatt space NPP use lithium as a coolant and niobium alloy as a structural material. In order to refine the lithium-niobium technology of the material and design engineering, lithium-niobium loops were worked out in RSC Energia, and they were tested at a working temperature of lithium equal to 1070-1300 K. In order to measure the lithium flow and pressure, special gauges were developed, which made possible the calibration and checkout of the loops without their dismantling. The paper describes the architecture of the electromagnetic flowmeter and the electromagnetic vibrating-wire pressure transducer (gauge) for lithium coolant in the nuclear power plant cooling systems. The operating principles of these meters are presented. Flowmeters have been developed for channel diameters ranging from 10 to 100 mm, which are capable of measuring lithium flows in the range of 0.1 to 30 L/s with the error of 3% for design calibration and 1% for volume graduation. The temperature error of the pressure transducers does not exceed 0.4% per 100 K; the nonlinearity and hysteresis of the calibration curve do not exceed 0.3 and 0.4%, respectively. The transducer applications are illustrated by the examples of results obtained from tests on the NPP module mockup and heat pipes of a radiation cooler.

  8. Preliminary Study on Utilization of Carbon Dioxide as a Coolant of High Temperature Engineering Test Reactor with MOX and Minor Actinides Fuel

    NASA Astrophysics Data System (ADS)

    Fauzia, A. F.; Waris, A.; Novitrian

    2010-06-01

    High temperature engineering test reactor (HTTR) is an uranium oxide (UO2) fuel, graphite moderator and helium gas-cooled reactor with 30 MW in thermal output and outlet coolant temperature of 950° C. Instead of using helium gas, we have utilized carbon dioxide as a coolant in the present study. Beside that, uranium and plutonium oxide (mixed oxide, MOX) and minor actinides have been employed as a new fuel type of HTTR. Utilization of plutonium and minor actinide is one of the support system to non-proliferation issue in the nuclear development. The enrichment for uranium oxide has been varied of 6-20% with plutonium and minor actinides concentration of 10%. In this study, burnup period is 1100 days. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. Reactor core calculation was done by using CITATION module. The result shows that HTTR can achieve its criticality condition with 14% of 235 U enrichment.

  9. Experimental investigations of heat transfer and temperature fields in models simulating fuel assemblies used in the core of a nuclear reactor with a liquid heavy-metal coolant

    NASA Astrophysics Data System (ADS)

    Belyaev, I. A.; Genin, L. G.; Krylov, S. G.; Novikov, A. O.; Razuvanov, N. G.; Sviridov, V. G.

    2015-09-01

    The aim of this experimental investigation is to obtain information on the temperature fields and heat transfer coefficients during flow of liquid-metal coolant in models simulating an elementary cell in the core of a liquid heavy metal cooled fast-neutron reactor. Two design versions for spacing fuel rods in the reactor core were considered. In the first version, the fuel rods were spaced apart from one another using helical wire wound on the fuel rod external surface, and in the second version spacer grids were used for the same purpose. The experiments were carried out on the mercury loop available at the Moscow Power Engineering Institute National Research University's Chair of Engineering Thermal Physics. Two experimental sections simulating an elementary cell for each of the fuel rod spacing versions were fabricated. The temperature fields were investigated using a dedicated hinged probe that allows temperature to be measured at any point of the studied channel cross section. The heat-transfer coefficients were determined using the wall temperature values obtained at the moment when the probe thermocouple tail end touched the channel wall. Such method of determining the wall temperature makes it possible to alleviate errors that are unavoidable in case of measuring the wall temperature using thermocouples placed in slots milled in the wall. In carrying out the experiments, an automated system of scientific research was applied, which allows a large body of data to be obtained within a short period of time. The experimental investigations in the first test section were carried out at Re = 8700, and in the second one, at five values of Reynolds number. Information about temperature fields was obtained by statistically processing the array of sampled probe thermocouple indications at 300 points in the experimental channel cross section. Reach material has been obtained for verifying the codes used for calculating velocity and temperature fields in channels with

  10. Exploratory Investigation of Transpiration Cooling of a 40 deg Double Wedge using Nitrogen and Helium as Coolants at Stagnation Temperatures from 1,295 deg F to 2,910 deg F

    NASA Technical Reports Server (NTRS)

    Rashis, Bernard

    1961-01-01

    An investigation of transpiration cooling has been conducted in the preflight jet of the Langley Pilotless Aircraft Research Station at Wallops Island, Va. The model consisted of a double wedge of 40 deg included angle having a porous stainless-steel specimen inserted flush with the top surface of the wedge. The tests were conducted at a free-stream Mach number of 2.0 for stagnation temperatures ranging from 1,295 F to 2,910 F. Nitrogen and helium were used as coolants and tests were conducted for values ranging from approximately 0.03 to 0.30 percent of the local weight flow rate. The data for both the nitrogen and helium coolants indicated greater cooling effectiveness than that predicted by theory and were in good agreement with the results for an 8 deg cone tested at a stagnation temperature of 600 F. The results indicate that the helium coolant, for the same amount of heat-transfer reduction, requires only about one-fourth to one-fifth the coolant flow weight as the nitrogen coolant.

  11. Preliminary studies of coolant by-pass flows in a prismatic very high temperature reactor using computational fluid dynamics

    SciTech Connect

    Hiroyuki Sato; Richard Johnson; Richard Schultz

    2009-09-01

    Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass flow in the reactor core.

  12. Effects of coolant temperature and pump power on the power output of solar-pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Thompson, George A.; Yogev, Amnon; Reich, A.; Oron, Moshe

    1992-11-01

    The temperature dependence of solar-pumped solid state lasers of Nd:YAG and two types of Nd:Cr:GSGG was studied over the temperature range of +30 to -60 C in a quasi-CW mode. All lasers had higher output powers at -40 C. The Nd:Cr:GSGG laser with a chromium concentration of 2.5 at. pct produced 70 W of power at -40 C, quasi-CW. If extrapolated to true CW operation this is equivalent to 350 W. The temperature dependence of the laser performance is attributed to changes in both the stimulated emission cross section and the resonator configuration.

  13. Purification of liquid metal systems with sodium coolant from oxygen using getters

    NASA Astrophysics Data System (ADS)

    Kozlov, F. A.; Konovalov, M. A.; Sorokin, A. P.

    2016-05-01

    For increasing the safety and economic parameters of nuclear power stations (NPSs) with sodium coolant, it was decided to install all systems contacting radioactive sodium, including purification systems of circuit I, in the reactor vessel. The performance and capacity of cold traps (CTs) (conventional element of coolant purification systems) in these conditions are limited by their volume. It was proposed to use hot traps (HTs) in circuit I for coolant purification from oxygen. It was demonstrated that, at rated parameters of the installation when the temperature of the coolant streamlining the getter (gas absorber) is equal to 550°C, the hot trap can provide the required coolant purity. In shutdown modes at 250-300°C, the performance of the hot trap is reduced by four orders of magnitude. Possible HT operation regimes for shutdown modes and while reaching rated parameters were proposed and analyzed. Basic attention was paid to purification modes at power rise after commissioning and accidental contamination of the coolant when the initial oxygen concentration in it reached 25 mln-1. It was demonstrated that the efficiency of purification systems can be increased using HTs with the getter in the form of a foil or granules. The possibility of implementing the "fast purification" mode in which the coolant is purified simultaneously with passing over from the shutdown mode to the rated parameters was substantiated.

  14. Machine coolant waste reduction by optimizing coolant life. Project summary

    SciTech Connect

    Pallansch, J.

    1995-08-01

    The project was designed to study the following: A specific water-soluble coolant (Blasocut 2000 Universal) in use with a variety of machines, tools, and materials; Coolant maintenance practices associated with three types of machines; Health effects of use and handling of recycled coolant; Handling practices for chips and waste coolant; Chip/coolant separation; and Oil/water separation.

  15. Temperature-dependent shock initiation of LX-17 explosive

    SciTech Connect

    Lee, R.S.; Chau, H.H.; Druce, R.L.; Moua, K.

    1995-02-01

    LX-17 samples, heated to temperatures up to 250 C, were impacted by 3 to 10-mm-wide, 50.8-mm-long strips of 0.13-mm-thick Kapton polyimide film at velocities up to 7.7 km/s. The Kapton strips were laminated onto a thin aluminum bridge foil and were launched to the desired velocity by discharging a capacitor bank through the foil, causing the foil to explode. The LX-17 samples were confined in a steel holder and heated in an oven to the desired temperature. After the capacitor bank was charged, the LX-17 sample in its steel holder was remotely drawn out of the oven on rails and positioned over the bridge-foil/Kapton-strip laminate. When the sample was in position, the bank was discharged, launching the Kapton strip against the LX-17 surface. The shock initiation threshold was measured for 3, 7, and 10-mm-wide strips at room temperature, 200 C and 250 C. The authors found a significant reduction in the velocity threshold and in the critical area for initiation when the samples were heated. The authors compare the results with the earlier data of Bloom, who measured the initiation threshold of LX-17 over the density range 1.8--1.91 g/cm{sup 3} at room temperature and {minus}54 C. LX-17 has a large coefficient of thermal expansion, as reported by Urtiew, et al., which reduces its density significantly t elevated temperatures. They find that the change of shock initiation threshold with temperature is consistent with the change in sample density, using the relation between threshold and density reported by Bloom.

  16. NUCLEAR REACTOR COOLANT

    DOEpatents

    Colichman, E.L.

    1959-10-20

    The formation of new reactor coolants which suppress polymerization resulting from pyrolytic and radiation decomposition is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to about 5% of beryllium or magnesium dispersed in the hydrocarbon.

  17. NUCLEAR REACTOR COOLANT

    DOEpatents

    Colichman, E.L.

    1959-10-20

    The formation of new reactor coolants which suppress polymerization resulting from pyrolitic and radiation decomposition is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to about 10% of an alkall metal dispersed in the hydrocarbon.

  18. Assessment of the Use of Nitrogen Trifluoride for Purifying Coolant and Heat Transfer Salts in the Fluoride Salt-Cooled High-Temperature Reactor

    SciTech Connect

    Scheele, Randall D.; Casella, Andrew M.

    2010-09-28

    This report provides an assessment of the use of nitrogen trifluoride for removing oxide and water-caused contaminants in the fluoride salts that will be used as coolants in a molten salt cooled reactor.

  19. Computing Flows Of Coolants In Turbomachines

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.

    1994-01-01

    Coolant Passage Flow (CPF) computer code developed to predict accurately coolant flow and heat transfer inside turbomachinery cooling passages (either radial or axial blading). Computes flow in one-inlet/one-outlet passage of any shape. Calculates rate of flow of coolant, temperature, pressure, velocity, and heat-transfer coefficients along passage. Integrates one-dimensional momentum and energy equations along defined flow path, taking into account change in area, addition or subtraction of mass, pumping, friction, and transfer of heat. Written in FORTRAN IV.

  20. The effect of fuel thermal conductivity on the behavior of LWR cores during loss-of-coolant accidents

    SciTech Connect

    Terrani, Kurt A.; Wang, Dean; Ott, Larry J.; Montgomery, Robert O.

    2014-05-01

    The effect of variation in thermal conductivity of light water reactor fuel elements on core response during loss-of-coolant accident scenarios is examined. Initially, a simplified numerical analysis is utilized to determine the time scales associated with dissipation of stored energy from the fuel into the coolant once the fission reaction is stopped. The analysis is then followed by full reactor system thermal-hydraulics analysis of a typical boiling and pressurized water reactor subjected to a large break loss-of-coolant accident scenario using the TRACE code. Accordingly, sensitivity analyses to examine the effect of an increase in fuel thermal conductivity, up to 500%, on fuel temperature evolution during these transients are performed. Given the major differences in thermal-hydraulics design aspects of boiling and pressurized water reactors, different fuel and temperature responses during the simulated loss-of-coolant transients are observed.

  1. Flow boiling test of GDP replacement coolants

    SciTech Connect

    Park, S.H.

    1995-08-01

    The tests were part of the CFC replacement program to identify and test alternate coolants to replace CFC-114 being used in the uranium enrichment plants at Paducah and Portsmouth. The coolants tested, C{sub 4}F{sub 10} and C{sub 4}F{sub 8}, were selected based on their compatibility with the uranium hexafluoride process gas and how well the boiling temperature and vapor pressure matched that of CFC-114. However, the heat of vaporization of both coolants is lower than that of CFC-114 requiring larger coolant mass flow than CFC-114 to remove the same amount of heat. The vapor pressure of these coolants is higher than CFC-114 within the cascade operational range, and each coolant can be used as a replacement coolant with some limitation at 3,300 hp operation. The results of the CFC-114/C{sub 4}F{sub 10} mixture tests show boiling heat transfer coefficient degraded to a minimum value with about 25% C{sub 4}F{sub 10} weight mixture in CFC-114 and the degree of degradation is about 20% from that of CFC-114 boiling heat transfer coefficient. This report consists of the final reports from Cudo Technologies, Ltd.

  2. MACHINE COOLANT WASTE REDUCTION BY OPTIMIZING COOLANT LIFE

    EPA Science Inventory

    Machine shops use coolants to improve the life and function of machine tools. hese coolants become contaminated with oils with use, and this contamination can lead to growth of anaerobic bacteria and shortened coolant life. his project investigated methods to extend coolant life ...

  3. The DARPA manufacturing initiative in high temperature superconductivity

    SciTech Connect

    Adams, K.R. )

    1989-01-01

    The Defense Advanced Research Projects Agency (DARPA) has a very aggressive Technology Base program in high temperature superconductivity. This program is expected to provide the basis for a specialized set of military products - passive microwave and millimeter wave devices - within the next three years. In order to get these high leverage products into military systems, a manufacturing base must be developed for HTSC components. A plan for DARPA in HTSC manufacturing is directly coupled with the ongoing DARPA materials and device oriented R and D program. In essence, this plan recommends a three phased effort: 1. Phase I (two years); Fund companies through R and D contracts for specialized HTSC components; prepare a detailed plan and develop an HTSC consortium. 2. Phase II (six years): Establish an HTSC Sematech initiative for electronic applications, including active devices. 3. Phase III (optional): Continue the HTSC Sematech with emphasis on high power applications.

  4. Lead Coolant Test Facility Development Workshop

    SciTech Connect

    Paul A. Demkowicz

    2005-06-01

    A workshop was held at the Idaho National Laboratory on May 25, 2005, to discuss the development of a next generation lead or lead-alloy coolant test facility. Attendees included representatives from the Generation IV lead-cooled fast reactor (LFR) program, Advanced Fuel Cycle Initiative, and several universities. Several participants gave presentations on coolant technology, existing experimental facilities for lead and lead-alloy research, the current LFR design concept, and a design by Argonne National Laboratory for an integral heavy liquid metal test facility. Discussions were focused on the critical research and development requirements for deployment of an LFR demonstration test reactor, the experimental scope of the proposed coolant test facility, a review of the Argonne National Laboratory test facility design, and a brief assessment of the necessary path forward and schedule for the initial stages of this development project. This report provides a summary of the presentations and roundtable discussions.

  5. Radiant energy receiver having improved coolant flow control means

    DOEpatents

    Hinterberger, H.

    1980-10-29

    An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.

  6. Environmentally Friendly Coolant System

    SciTech Connect

    David Jackson Principal Investigator

    2011-11-08

    Energy reduction through the use of the EFCS is most improved by increasing machining productivity. Throughout testing, nearly all machining operations demonstrated less land wear on the tooling when using the EFCS which results in increased tool life. These increases in tool life advance into increased productivity. Increasing productivity reduces cycle times and therefore reduces energy consumption. The average energy savings by using the EFCS in these machining operations with these materials is 9%. The advantage for end milling stays with flood coolant by about 6.6% due to its use of a low pressure pump. Face milling and drilling are both about 17.5% less energy consumption with the EFCS than flood coolant. One additional result of using the EFCS is improved surface finish. Certain machining operations using the EFCS result in a smoother surface finish. Applications where finishing operations are required will be able to take advantage of the improved finish by reducing the time or possibly eliminating completely one or more finishing steps and thereby reduce their energy consumption. Some machining operations on specific materials do not show advantages for the EFCS when compared to flood coolants. More information about these processes will be presented later in the report. A key point to remember though, is that even with equivalent results, the EFCS is replacing petroleum based coolants whose production produces GHG emissions and create unsafe work environments.

  7. A Heated Tube Facility for Rocket Coolant Channel Research

    NASA Technical Reports Server (NTRS)

    Green, James M.; Pease, Gary M.; Meyer, Michael L.

    1995-01-01

    The capabilities of a heated tube facility used for testing rocket engine coolant channels at the NASA Lewis Research Center are presented. The facility uses high current, low voltage power supplies to resistively heat a test section to outer wall temperatures as high as 730 C (1350 F). Liquid or gaseous nitrogen, gaseous helium, or combustible liquids can be used as the test section coolant. The test section is enclosed in a vacuum chamber to minimize heat loss to the surrounding system. Test section geometry, size, and material; coolant properties; and heating levels can be varied to generate heat transfer and coolant performance data bases.

  8. Automatic coolant flow control device for a nuclear reactor assembly

    DOEpatents

    Hutter, E.

    1984-01-27

    A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

  9. Development of Figure of Merits (FOMs) for Intermediate Coolant Characterization and Selection

    SciTech Connect

    Eung Soo Kim; Piyush Sabharwall; Nolan Anderson

    2011-06-01

    This paper focuses on characterization of several coolant performances in the IHTL. There are lots of choices available for the IHTL coolants; gases, liquid metals, molten salts, and etc. Traditionally, the selection of coolants is highly dependent on engineer's experience and decisions. In this decision, the following parameters are generally considered: melting point, vapor pressure, density, thermal conductivity, heat capacity, viscosity, and coolant chemistry. The followings are general thermal-hydraulic requirements for the coolant in the IHTL: (1) High heat transfer performance - The IHTL coolant should exhibit high heat transfer performance to achieve high efficiency and economics; (2) Low pumping power - The IHTL coolant requires low pumping power to improve economics through less stringent pump requirements; (3) Low amount of coolant volume - The IHTL coolant requires less coolant volume for better economics; (4) Low amount of structural materials - The IHTL coolant requires less structural material volume for better economics; (5) Low heat loss - The IHTL requires less heat loss for high efficiency; and (6) Low temperature drop - The IHTL should allow less temperature drop for high efficiency. Typically, heat transfer coolants are selected based on various fluid properties such as melting point, vapor pressure, density, thermal conductivity, heat capacity, viscosity, and coolant chemistry. However, the selection process & results are highly dependent on the engineer's personal experience and skills. In the coolant selection, if a certain coolant shows superior properties with respect to the others, the decision will be very straightforward. However, generally, each coolant material exhibits good characteristics for some properties but poor for the others. Therefore, it will be very useful to have some figures of merits (FOMs), which can represent and quantify various coolant thermal performances in the system of interest. The study summarized in this

  10. Reactor coolant pump flywheel

    SciTech Connect

    Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph

    2013-11-26

    A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

  11. Method for removing cesium from a nuclear reactor coolant

    DOEpatents

    Colburn, Richard P.

    1986-01-01

    A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium

  12. 14 CFR 23.1063 - Coolant tank tests.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... greater, plus the maximum working pressure of the system; and (b) For a tank with a nonmetallic liner the... specimen liner must be conducted with the coolant at operating temperature. Induction System...

  13. 14 CFR 23.1063 - Coolant tank tests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... greater, plus the maximum working pressure of the system; and (b) For a tank with a nonmetallic liner the... specimen liner must be conducted with the coolant at operating temperature. Induction System...

  14. 14 CFR 23.1063 - Coolant tank tests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... greater, plus the maximum working pressure of the system; and (b) For a tank with a nonmetallic liner the... specimen liner must be conducted with the coolant at operating temperature. Induction System...

  15. 14 CFR 23.1063 - Coolant tank tests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... greater, plus the maximum working pressure of the system; and (b) For a tank with a nonmetallic liner the... specimen liner must be conducted with the coolant at operating temperature. Induction System...

  16. 14 CFR 23.1063 - Coolant tank tests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... greater, plus the maximum working pressure of the system; and (b) For a tank with a nonmetallic liner the... specimen liner must be conducted with the coolant at operating temperature. Induction System...

  17. Load following capability of CANDLE reactor by adjusting coolant operation condition

    SciTech Connect

    Sekimoto, Hiroshi; Nakayama, Sinsuke

    2012-06-06

    The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and {sup 208}Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

  18. Load following capability of CANDLE reactor by adjusting coolant operation condition

    NASA Astrophysics Data System (ADS)

    Sekimoto, Hiroshi; Nakayama, Sinsuke

    2012-06-01

    The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and 208Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

  19. Effect of initial temperature on water aggregation at a cold surface.

    PubMed

    Kier, Lemont B; Cheng, Chao-Kun

    2013-01-01

    Cellular automata models of water at two initial temperatures were created. Each model was exposed to a freezing surface. The formation of fully bonded water cells, f(4), was observed over time, beginning with a model of initially warm water and with initially cool water. The warm water formed more f(4) cells earlier than the initially cool water. A high percentage of f(4) cells is interpreted as the formation of ice. This is a model of the Mpemba effect. A description of the initial states for these two temperatures is offered in explanation of this effect. PMID:23341213

  20. Circulation within the primary system at TMI-2 with lowered coolant level and at atmospheric conditions

    SciTech Connect

    Baston, V.F.; Hofstetter, K.J.; Malinauskas, A.P.

    1985-06-01

    Experiments were performed with the Three Mile Island reactor coolant system open to the atmosphere and the coolant lowered to a level above the fuel (a condition required for defueling) to ascertain the extent of coolant mixing. A principal concern for coolant decontamination during defueling is the radionuclides released and their distribution within the primary system. Analyses of radionuclide, temperature, and dissolved oxygen data taken during these experiments confirm mixing in the primary system under forced coolant flow conditions with only minimal mixing occurring during static periods.

  1. Coolant passage heat transfer with rotation

    NASA Astrophysics Data System (ADS)

    Hajek, T. J.; Wagner, J.; Johnson, B. V.

    1986-10-01

    In current and advanced gas turbine engines, increased speeds, pressures and temperatures are used to reduce specific fuel consumption and increase thrust/weight ratios. Hence, the turbine airfoils are subjected to increased heat loads escalating the cooling requirements to satisfy life goals. The efficient use of cooling air requires that the details of local geometry and flow conditions be adequately modeled to predict local heat loads and the corresponding heat transfer coefficients. The objective of this program is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

  2. Proposed reactor coolant density monitor

    SciTech Connect

    Mackley, A.D.

    1986-01-01

    Until now there has been no feasible method of monitoring coolant density in the environment of an operating reactor core. By analysis of output from self-powered neutron detectors (SPNDs) in the core of the Loss of Fluid Test (LOFT) Reactor, the author has successfully estimated local coolant densities under post-scram conditions during a large break loss of coolant transient. The model used for estimation is not fully explained by published principles on the interaction of gamma rays with SPNDs. However, based on the success of the model, the author proposes employing self powered gamma detectors (SPGDs) to monitor reactor coolant density and discusses areas of experimental work to establish the best conditions for this application. 9 refs., 12 figs.

  3. Large break loss-of-coolant accident analyses for the high flux isotope reactor

    SciTech Connect

    Taleyarkhan, R.P. )

    1989-01-01

    The US Department of Energy's High Flux Isotope Reactor (HFIR) was analyzed to evaluate it's response to a spectrum of loss-of-coolant accidents (LOCAs) with potential for leading to core damage. The MELCOR severe accident analysis code (version 1.7.1) was used to evaluate the overall dynamic response of HFIR. Before conducting LOCA analyses, the steady-state thermal-hydraulic parameters evaluated by MELCOR for various loop sections were verified against steady-state operating data. Thereafter, HFIR depressurization tests were simulated to evaluate the system pressure change for a given depletion in coolant inventory. Interesting and important safety-related phenomena were observed. The current analyses (which should be considered preliminary) that occur over a period from 1 to 3 seconds do not lead to core wide fuel melting. Core fluid flashing during the initial rapid depressurization does cause fuel temperature excursions due to adiabatic-like heatup. 3 refs., 4 figs.

  4. Small-break loss-of-coolant accidents in the updated PIUS 600 advanced reactor design

    SciTech Connect

    Boyack, B.E.; Steiner, J.L.; Harmony, S.C.

    1995-09-01

    The PIUS advanced reactor is a 640-MWe pressurized water reactor developed by Asea Brown Boveri (ABB). A unique feature of the PIUS concept is the absence of mechanical control and shutdown rods. Reactivity is normally controlled by coolant boron concentration and the temperature of the moderator coolant. ABB submitted the PIUS design to the US Nuclear Regulatory Commission (NRC) for preapplication review, and Los Alamos supported the NRC`s review effort. Baseline analyses of small-break initiators at two locations were performed with the system neutronic and thermal-hydraulic analysis code TRAC-PF1/MOD2. In addition, sensitivity studies were performed to explore the robustness of the PIUS concept to severe off-normal conditions having a very low probability of occurrence.

  5. Estimation of Surface Heat Flux and Surface Temperature during Inverse Heat Conduction under Varying Spray Parameters and Sample Initial Temperature

    PubMed Central

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa. PMID:24977219

  6. Estimation of surface heat flux and surface temperature during inverse heat conduction under varying spray parameters and sample initial temperature.

    PubMed

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong; Zubair, Muhammad

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m(2) was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa. PMID:24977219

  7. Treatment of mixed waste coolant

    SciTech Connect

    Kidd, S.; Bowers, J.S.

    1995-09-01

    The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meetings the sanitary sewer discharge limits and subsequent Land Disposal REstriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered {open_quotes}Best Demonstrated Available Technologies,{close_quotes} or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a mutiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.

  8. Treatment of mixed waste coolant

    SciTech Connect

    Kidd, S.; Bowers, J.S.

    1995-02-01

    The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meeting the sanitary sewer discharge limits and subsequent Land Disposal Restriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered Best Demonstrated Available Technologies, or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a multiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.

  9. 1996 Coolant Flow Management Workshop

    NASA Technical Reports Server (NTRS)

    Hippensteele, Steven A. (Editor)

    1997-01-01

    The following compilation of documents includes a list of the 66 attendees, a copy of the viewgraphs presented, and a summary of the discussions held after each session at the 1996 Coolant Flow Management Workshop held at the Ohio Aerospace Institute, adjacent to the NASA Lewis Research Center, Cleveland, Ohio on December 12-13, 1996. The workshop was organized by H. Joseph Gladden and Steven A. Hippensteele of NASA Lewis Research Center. Participants in this workshop included Coolant Flow Management team members from NASA Lewis, their support service contractors, the turbine engine companies, and the universities. The participants were involved with research projects, contracts and grants relating to: (1) details of turbine internal passages, (2) computational film cooling capabilities, and (3) the effects of heat transfer on both sides. The purpose of the workshop was to assemble the team members, along with others who work in gas turbine cooling research, to discuss needed research and recommend approaches that can be incorporated into the Center's Coolant Flow Management program. The workshop was divided into three sessions: (1) Internal Coolant Passage Presentations, (2) Film Cooling Presentations, and (3) Coolant Flow Integration and Optimization. Following each session there was a group discussion period.

  10. Method for removing cesium from a nuclear reactor coolant

    DOEpatents

    Colburn, R.P.

    1983-08-10

    A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium inventory thereof further into the carbon matrix while simultaneously redispersing a portion into the regeneration system for absorption at a reduced temperature by the secondary trap.

  11. Coolant-side heat-transfer rates for a hydrogen-oxygen rocket and a new technique for data correlation

    NASA Technical Reports Server (NTRS)

    Schacht, R. L.; Quentmeyer, R. J.

    1973-01-01

    An experimental investigation was conducted to determine the coolant-side, heat transfer coefficients for a liquid cooled, hydrogen-oxygen rocket thrust chamber. Heat transfer rates were determined from measurements of local hot gas wall temperature, local coolant temperature, and local coolant pressure. A correlation incorporating an integration technique for the transport properties needed near the pseudocritical temperature of liquid hydrogen gives a satisfactory prediction of hot gas wall temperatures.

  12. COOLANT STABILIZED WITH KETONE

    DOEpatents

    Burr, J.G.; Strong, J.D.

    1961-11-21

    sion). U. S. Patent 3,009.88l. Nov. 2l, l06l. A method is given for inhibiting radiolytic damage to a polyphenyl composition undergoing nuclear irradiation, the polyphenyl composition initially consisting essentially of polyphenyls having 2 to 4 phenyl rings. The method comprises adding approximately 5 mole% anthraquinone to the polyphenyl composition. (AEC)

  13. Long life coolant pump technology

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Design concepts were investigated to improve space system coolant pump technology to be suitable for mission durations of two years and greater. These design concepts included an improved bearing system for the pump rotating elements, consisting of pressurized conical bearings. This design was satisfactorily endurance tested as was a new prototype pump built using various other improved design concepts. Based upon an overall assessment of the results of the program it is concluded that reliable coolant pumps can be designed for three year space missions.

  14. Evaluation of engine coolants under flow boiling conditions

    SciTech Connect

    McAssey, E.V. Jr.; Stinson, C.; Gollin, M.

    1995-12-31

    An experimental program has been conducted to evaluate the heat transfer performance of two engine coolant mixtures, propylene-glycol/water and ethylene-glycol/water. In each mixture, the concentration was 50-50 by volume. Performance in this situation is defined as the ability to maintain a lower surface temperature for a given flux. The heat transfer regimes considered covered the range from single phase forced convection through saturated flow boiling. Results show that both coolants perform satisfactorily. However, in single phase convection, ethylene-glycol/water is slightly more effective. Conversely, for sub-cooled nucleate boiling and saturated boiling, propylene-glycol/water results in slightly lower metal temperatures.

  15. Degradation of soil fumigants as affected by initial concentration and temperature.

    PubMed

    Ma, Q L; Gan, J; Papiernik, S K; Becker, J O; Yates, S R

    2001-01-01

    Soil fumigation using shank injection creates high fumigant concentration gradients in soil from the injection point to the soil surface. A temperature gradient also exists along the soil profile. We studied the degradation of methyl isothiocyanate (MITC) and 1,3-dichloropropene (1,3-D) in an Arlington sandy loam (coarse-loamy, mixed, thermic Haplic Durixeralf) at four temperatures and four initial concentrations. We then tested the applicability of first-order, half-order, and second-order kinetics, and the Michaelis-Menten model for describing fumigant degradation as affected by temperature and initial concentration. Overall, none of the models adequately described the degradation of MITC and 1,3-D isomers over the range of the initial concentrations. First-order and half-order kinetics adequately described the degradation of MITC and 1,3-D isomers at each initial concentration, with the correlation coefficients greater than 0.78 (r2> 0.78). However, the derived rate constant was dependent on the initial concentration. The first-order rate constants varied between 6 and 10x for MITC for the concentration range of 3 to 140 mg kg(-1), and between 1.5 and 4x for 1,3-D isomers for the concentration range of 0.6 to 60 mg kg(-1), depending on temperature. For the same initial concentration range, the variation in the half-order rate constants was between 1.4 and 1.7x for MITC and between 3.1 and 6.1x for 1,3-D isomers, depending on temperature. Second-order kinetics and the Michaelis-Menten model did not satisfactorily describe the degradation at all initial concentrations. The degradation of MITC and 1,3-D was primarily biodegradation, which was affected by temperature between 20 and 40 degrees C, following the Arrhenius equation (r2 > 0.74). PMID:11476506

  16. Initial hydrogen detonation data from the High-Temperature Combustion Facility

    SciTech Connect

    Ginsberg, T.; Ciccarelli, G.; Boccio, J.

    1994-12-31

    The Brookhaven National Laboratory High-Temperature Combustion Facility (HTCF) is described and data from initial hydrogen detonation experiments are presented. Initial phase of the inherent detonability experimental program is described. Test gases thus far tested are hydrogen-air mixtures at one atmosphere initial pressure and temperatures 300K-650K. Detonation pressure, wave speed, and detonation cell size were measured. Data were consistent with earlier SSDA (small-scale development apparatus) test results. HTCF results confirm the conclusion from the SSDA program that the gas temperature decreases the cell size and, therefore, increases the sensitivity of mixtures to detonation. Data from the larger HTCF test vessel, however, also demonstrates that the effect of increased scale is to extend the range of detonable mixtures to lower concentration.

  17. Initial Operation of the High Temperature Electrolysis Integrated Laboratory Scale Experiment at INL

    SciTech Connect

    C. M. Stoots; J. E. O'Brien; K. G. Condie; J. S. Herring; J. J. Hartvigsen

    2008-06-01

    An integrated laboratory scale, 15 kW high-temperature electrolysis facility has been developed at the Idaho National Laboratory under the U.S. Department of Energy Nuclear Hydrogen Initiative. Initial operation of this facility resulted in over 400 hours of operation with an average hydrogen production rate of approximately 0.9 Nm3/hr. The integrated laboratory scale facility is designed to address larger-scale issues such as thermal management (feed-stock heating, high-temperature gas handling), multiple-stack hot-zone design, multiple-stack electrical configurations, and other “integral” issues. This paper documents the initial operation of the ILS, with experimental details about heat-up, initial stack performance, as well as long-term operation and stack degradation.

  18. Vertical reactor coolant pump instabilities

    NASA Technical Reports Server (NTRS)

    Jones, R. M.

    1985-01-01

    The investigation conducted at the Tennessee Valley Authority's Sequoyah Nuclear Power Plant to determine and correct increasing vibrations in the vertical reactor coolant pumps is described. Diagnostic procedures to determine the vibration causes and evaluate the corrective measures taken are also described.

  19. Effect of initial temperature and concentration of catalyst in polyeugenol production

    NASA Astrophysics Data System (ADS)

    Widayat, Fatuchrohman, Alviano; Gustiasih, Ellen

    2015-12-01

    Objective of this research to study influencing of sulfuric acid concentration and initials temperature on polymerization of eugenol. Eugenol is the largest compound in the clove oil that used as raw material. Eugenol was polymerized laboratory scale. Polymerization processing conducted in reactor at 30 minutes. Polyeugenol was obtained in polymerization was conducted at temperature 40°C and ratio eugenol to sulfuric acid 1:15 mole. This research was pbtained the highest yield 81.49%. However, the weight would be increase in according with increasing of initial temperature. The polymerization in temperature 50°C with 1:1.5 mole ratio has the heaviest molecule weight; 47,530.76 gr/mole.

  20. Effect of initial temperature and concentration of catalyst in polyeugenol production

    SciTech Connect

    Widayat

    2015-12-29

    Objective of this research to study influencing of sulfuric acid concentration and initials temperature on polymerization of eugenol. Eugenol is the largest compound in the clove oil that used as raw material. Eugenol was polymerized laboratory scale. Polymerization processing conducted in reactor at 30 minutes. Polyeugenol was obtained in polymerization was conducted at temperature 40°C and ratio eugenol to sulfuric acid 1:15 mole. This research was pbtained the highest yield 81.49%. However, the weight would be increase in according with increasing of initial temperature. The polymerization in temperature 50°C with 1:1.5 mole ratio has the heaviest molecule weight; 47,530.76 gr/mole.

  1. CFD modeling of turbulent duct flows for coolant channel analysis

    NASA Astrophysics Data System (ADS)

    Ungewitter, Ronald J.; Chan, Daniel C.

    1993-07-01

    The design of modern liquid rocket engines requires the analysis of chamber coolant channels to maximize the heat transfer while minimizing the coolant flow. Coolant channels often do not remain at a constant cross section or at uniform curvature. New designs require higher aspect ratio coolant channels than previously used. To broaden the analysis capability and to complement standard analysis tools an investigation on the accuracy of CFD predictions for coolant channel flow has been initiated. Validation of CFD capabilities for coolant channel analysis will enhance the capabilities for optimizing design parameters without resorting to extensive experimental testing. The eventual goal is to use CFD to determine the flow fields of unique coolant channel designs and therefore determine critical heat transfer coefficients. In this presentation the accuracy of a particular CFD code is evaluated for turbulent flows. The first part of the presentation is a comparison of numerical results to existing cold flow data for square curved ducts (NASA CR-3367, 'Measurements of Laminar and Turbulent Flow in a Curved Duct with Thin Inlet Boundary Layers'). The results of this comparison show good agreement with the relatively coarse experimental data. The second part of the presentation compares two cases of higher aspect ratio channels (AR=2.5,10) to show changes in axial and secondary flow strength. These cases match experimental work presently in progress and will be used for future validation. The comparison shows increased secondary flow strength of the higher aspect ratio case due to the change in radius of curvature. The presentation includes a test case with a heated wall to demonstrate the program's capability. The presentation concludes with an outline of the procedure used to validate the CFD code for future design analysis.

  2. Code System to Calculate Reactor Coolant System Leak Rate.

    SciTech Connect

    Bell, Pat

    1999-10-19

    Version 00 RCSLK9 was developed to analyze the leak tightness of the primary coolant system for any pressurized water reactor (PWR). From given system conditions, water levels in tanks, and certain system design parameters, RCSLK9 calculates the loss of water from the reactor coolant system (RCS) and the increase of water in the leakage collection system during an arbitrary time interval. The program determines the system leak rates and displays or prints a report of the results. During the initial application to a specific reactor, RCSLK9 creates a file of system parameters and saves it for future use.

  3. Code System to Calculate Reactor Coolant System Leak Rate.

    Energy Science and Technology Software Center (ESTSC)

    1999-10-19

    Version 00 RCSLK9 was developed to analyze the leak tightness of the primary coolant system for any pressurized water reactor (PWR). From given system conditions, water levels in tanks, and certain system design parameters, RCSLK9 calculates the loss of water from the reactor coolant system (RCS) and the increase of water in the leakage collection system during an arbitrary time interval. The program determines the system leak rates and displays or prints a report ofmore » the results. During the initial application to a specific reactor, RCSLK9 creates a file of system parameters and saves it for future use.« less

  4. Data center coolant switch

    SciTech Connect

    Iyengar, Madhusudan K.; Parida, Pritish R.; Schultz, Mark D.

    2015-10-06

    A data center cooling system is operated in a first mode; it has an indoor portion wherein heat is absorbed from components in the data center, and an outdoor heat exchanger portion wherein outside air is used to cool a first heat transfer fluid (e.g., water) present in at least the outdoor heat exchanger portion of the cooling system during the first mode. The first heat transfer fluid is a relatively high performance heat transfer fluid (as compared to the second fluid), and has a first heat transfer fluid freezing point. A determination is made that an appropriate time has been reached to switch from the first mode to a second mode. Based on this determination, the outdoor heat exchanger portion of the data cooling system is switched to a second heat transfer fluid, which is a relatively low performance heat transfer fluid, as compared to the first heat transfer fluid. It has a second heat transfer fluid freezing point lower than the first heat transfer fluid freezing point, and the second heat transfer fluid freezing point is sufficiently low to operate without freezing when the outdoor air temperature drops below a first predetermined relationship with the first heat transfer fluid freezing point.

  5. Nickel sulfide formation at low temperature: initial precipitates, solubility and transformation products

    EPA Science Inventory

    The formation of nickel sulfides has been examined experimentally over the temperature range from 25 to 60°C. At all conditions studied, hexagonal (α-NiS) was the initial precipitate from solution containing Ni2+ and dissolved sulfide. The formation of millerite (β- NiS, rhombo...

  6. A Knoevenagel Initiated Annulation Reaction Using Room Temperature or Microwave Conditions

    ERIC Educational Resources Information Center

    Cook, A. Gilbert

    2007-01-01

    An experiment is presented that has the student execute a Knoevenagel initiated annulation reaction. The reaction can be carried out either through use of a microwave reactor or by allowing the mixture to stand at room temperature for two days. The student is then challenged to identify the reaction product through a guided prelab exercise of the…

  7. A method for measuring cooling air flow in base coolant passages of rotating turbine blades

    NASA Technical Reports Server (NTRS)

    Liebert, C. H.; Pollack, F. G.

    1975-01-01

    Method accurately determines actual coolant mass flow rate in cooling passages of rotating turbine blades. Total and static pressures are measured in blade base coolant passages. Mass flow rates are calculated from these measurements of pressure, measured temperature and known area.

  8. Optimizing Production of Superconducting Bulk YBCO Crystals: Effects of Initial Temperature and Growth Time

    NASA Astrophysics Data System (ADS)

    Jolley, Erin; Shea, Connor; Hunting, Janet; Sullivan, M. C.

    We present our work on increasing both pinning force and critical temperature of bulk YBCO superconducting crystals. We optimized temperature profiles for growing bulk YBaCuO superconductors by varying (a) temperature and (b) growth time. We synthesize the precursor materials, superconducting Y1Ba2Cu3O7 (Y-123) and non-superconducting Y2Ba1Cu1O5 (Y-211), and mix the two in a 1:0.4 molar ratio before beginning melt textured growth. We heat the mixture to a temperature above the melting point of Y-123 but below the melting point of Y-211, where it is held until the Y-123 melts and the Y-211 impurities disperse in the mixture. The mixture is then quickly cooled to an initial temperature (a) near the peritectic point, and is then slowly cooled for 30-100 hours (b) to allow steady growth of large domain Y-123 crystals. We will discuss the effects of different initial temperatures near the peritectic point and growth times on the pinning force and critical temperature of these samples. This work was supported by NSF Grant DMR-1305637, and made use of the Cornell Center for Materials Research Shared Facilities which are supported through the NSF MRSEC program (Grant DMR-1120296).

  9. Fracture mechanics evaluation for at typical PWR primary coolant pipe

    SciTech Connect

    Tanaka, T.; Shimizu, S.; Ogata, Y.

    1997-04-01

    For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

  10. Initial conditioning of polymer eelectrolyte membrane fuel cell by temperature and potential cycling.

    PubMed

    Bezmalinović, Dario; Radošević, Jagoda; Barbir, Frano

    2015-01-01

    Polymer electrolyte membrane fuel cells need initial conditioning, activation or break-in the first time they are operated after being assembled. During this period performance of the fuel cell improves until it reaches its nominal performance. The exact mechanism of this initial conditioning is not completely understood, but it is assumed that during the conditioning process the polymer membrane, as well as the polymer in the catalyst layer, get humidified, and the number of active catalyst sites increases. Activation procedure proposed here consists of temperature and potential cycling. Temperature cycling is a new approach for the conditioning and the idea is to rapidly cool the running cell at some point to allow the membrane to equilibrate with condensed water which should result in higher intake of water within the membrane. The results show that proposed procedure is better or at least comparable to some conventional procedures for the initial conditioning. PMID:25830963

  11. Initiation Temperature for Runaway Tri-n-Butyl Phosphate/Nitric Acid Reaction

    SciTech Connect

    Rudisill, T.S.

    2000-11-28

    During a review of the H-Canyon authorization basis, Defense Nuclear Facility Safety Board (DNFSB) staff members questioned the margin of safety associated with a postulated tri-n-butyl phosphate (TBP)/nitric acid runaway reaction due to the inadvertent heating of a canyon tank containing greater than 3000 lbs (1362 kg) of TBP. The margin of safety was partially based on experiments and calculations performed by the Actinide Technology Section (ATS) to support deletion of indication of tank agitation as a Safety Class System. In the technical basis for deletion of this system, ATS personnel conservatively calculated the equilibrium temperature distribution of a canyon tank containing TBP and nitric acid layers which were inadvertently heated by a steam jet left on following a transfer. The maximum calculated temperature (128 degrees C) was compared to the minimum initiation temperature for a runaway reaction (greater than 130 degrees C) documented by experimental work in the mid 195 0s. In this work, the initiation temperature as a function of nitric acid concentration was measured for 0 and 20 wt percent dissolved solids. The DNFSB staff members were concerned that data for 0 wt percent dissolved solids were not conservative given the facts that data for 20 wt percent dissolved solids show initiation temperatures at or below 130 degrees C and H-Canyon solutions normally contained a small amount of dissolved solids.

  12. Haematite natural crystals: non-linear initial susceptibility at low temperature

    NASA Astrophysics Data System (ADS)

    Guerrero-Suarez, S.; Martín-Hernández, F.

    2016-06-01

    Several works have reported that haematite has non-linear initial susceptibility at room temperature, like pyrrhotite or titanomagnetite, but there is no explanation for the observed behaviours yet. This study sets out to determine which physical property (grain size, foreign cations content and domain walls displacements) controls the initial susceptibility. The performed measurements include microprobe analysis to determine magnetic phases different to haematite; initial susceptibility (300 K); hysteresis loops, SIRM and backfield curves at 77 and 300 K to calculate magnetic parameters and minor loops at 77 K, to analyse initial susceptibility and magnetization behaviours below Morin transition. The magnetic moment study at low temperature is completed with measurements of zero field cooled-field cooled and AC susceptibility in a range from 5 to 300 K. The minor loops show that the non-linearity of initial susceptibility is closely related to Barkhausen jumps. Because of initial magnetic susceptibility is controlled by domain structure it is difficult to establish a mathematical model to separate magnetic subfabrics in haematite-bearing rocks.

  13. The influence of initial temperature on flame acceleration and deflagration-to-detonation transition

    SciTech Connect

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.

    1996-07-01

    The influence of initial mixture temperature on deflagration-to-detonation transition (DDT) has been investigated experimentally. The experiments were carried out in a 27-cm-inner diameter, 21.3-meter-long heated detonation tube, which was equipped with periodic orifice plates to promote flame acceleration. Hydrogen-air-steam mixtures were tested at a range of temperatures up to 650K and at an initial pressure of 0.1 MPa. In most cases, the limiting hydrogen mole fraction which resulted in transition to detonation corresponded to the mixture whose detonation cell size, {lambda}, was approximately equal to the inner diameter of the orifice plate, d (e.g., d/{lambda}{approximately}1). The only exception was in dry hydrogen-air mixtures at 650K where the DDT limit was observed to be 11 percent hydrogen, corresponding to a value of d/{lambda} equal to 5.5. For a 10.5 percent hydrogen mixture at 650K, the flame accelerated to a maximum velocity of about 120 m/s and then decelerated to below 2 m/s. This observation indicates that the d/{lambda} = 1 DDT limit criterion provides a necessary condition but not a sufficient one for the onset of DDT in obstacle-laden ducts. In this particular case, the mixture initial condition (i.e., temperature) resulted in the inability of the mixture to sustain flame acceleration to the point where DDT could occur. It was also observed that the distance required for the flame to accelerate to the onset of detonation was a function of both the hydrogen mole fraction and the mixture initial temperature. For example, decreasing the hydrogen mole fraction or increasing the initial mixture temperature resulted in longer transition distances.

  14. Temperature comparison of initial, middle and final point of polypropylene friction stir welded

    NASA Astrophysics Data System (ADS)

    Kusharjanta, Bambang; Raharjo, Wahyu P.; Triyono

    2016-03-01

    Friction Stir Welding is known as a new solid state joining process. This process is applied in thermoplastic polymers material recently. One of member thermoplastic polymer is polypropylene. Polypropylene sheet 6 mm thick was friction stir welded with a cone cut steel pin. Tool rotation, travelling speed, and plunge depth, as welding parameters were 620 rpm, 7.3 mm/minutes and 0.02 mm respectively. Temperature at the initial, middle, and final point of advance side working piece were measured and compared. Measurement were done by thermocouple and recorded by data acquisition. Based on this research, it is concluded that temperature at the initial, middle and final point of friction stir welding process are different. The highest temperature peak reach at the middle point on the advance side which affects face bending strength.

  15. Transpiration cooling using air as a coolant

    SciTech Connect

    Kikkawa, Shinzo; Senda, Mamoru; Sakagushi, Katsuji; Shibutani, Hideki )

    1993-02-01

    Transpiration cooling is one of the most effective techniques for protecting a surface exposed to a high-temperature gas stream. In the present paper, the transpiration cooling effectiveness was measured under steady state. Air as a coolant was transpired from the surface of a porous plate exposed to hot gas stream, and the transpiration rate was varied in the range of 0.001 [approximately] 0.006. The transpiration cooling effectiveness was evaluated by measuring the temperature of the upper surface of the plate. Also, a theoretical study was performed and it was clarified that the effectiveness increases with increasing transpiration rate and heat-transfer coefficient of the upper surface. Further, the effectiveness was expressed as a function of the blowing parameter only. The agreement between the experimental results and theoretical ones was satisfactory.

  16. Influence of Cooling Water Temperature and Initial Heat Temperature of Bar On Heat Stress at the Bottom of V-shaped Notch

    NASA Astrophysics Data System (ADS)

    Zhang, Lijun; Zhao, Shengdun

    2008-11-01

    The finite element software, ANSYS, was applied to build the analyzed model of the slotted 20 steel bar. Influences of cooling water temperature and initial heat temperature of the bar on the heat stress near V-shaped notch tip were investigated in detail. The simulation results show that the initial heat temperature of the bar has a remarkable influence on the heat stress and the influence of the cooling water temperature can be neglected to some extent. The reasonable values of the initial heat temperature of the bar and the cooling water temperature are also obtained.

  17. Reactor coolant seal testing under station blackout conditions

    SciTech Connect

    Marsi, J.A.

    1988-01-01

    Failures of reactor coolant pump (RCP) seals that could result in a significant loss-of-coolant inventory are of current concern to the US Nuclear Regulatory Commission. Particular attention is being focused on seal behavior during station blackout conditions, when failure of on-site emergency diesel generators occurs simultaneously with loss of all off-site alternating current power. Under these conditions, both seal injection flow and component cooling water flow are lost, and the RCP seals are exposed to full reactor coolant temperature. Overheating of elastomeric components and flashing of coolant across the sealing faces can cause unacceptably high leakage rates, with potential catastrophic consequences. A test program has been conducted that subjects full-scale seal cartridges to typical pressurized water reactor (PWR) coolant system steady-state and transient operation conditions including associated dynamic shaft motions. A special test segment was developed to evaluate seal operation under station blackout conditions. The test program successfully mirrored the severity of an actual loss-of-seal cooling water event under station blackout conditions, and the Byron Jackson{reg sign} N-9000 seal cartridge maintained its integrity.

  18. Protein synthesis during the initial phase of the temperature-induced bleaching response in Euglena gracilis

    SciTech Connect

    Ortiz, W. )

    1990-05-01

    Growing cultures of photoheterotrophic Euglena gracilis experience an increase in chlorophyll accumulation during the initial phase of the temperature-induced bleaching response suggesting an increase in the synthesis of plastid components at the bleaching temperature of 33{degree}C. A primary goal of this work was to establish whether an increase in the synthesis of plastid proteins accompanies the observed increase in chlorophyll accumulation. In vivo pulse-labeling experiments with ({sup 35}S)sodium sulfate were carried out with cells grown at room temperature or at 33{degree}C. The synthesis of a number of plastid polypeptides of nucleocytoplasmic origin, including some presumably novel polypeptides, increased in cultures treated for 15 hours at 33{degree}C. In contrast, while synthesis of thylakoid proteins by the plastid protein synthesis machinery decreased modestly, synthesis of the large subunit of the enzyme ribulosebisphosphate carboxylase was strongly affected at the elevated temperature. Synthesis of novel plastid-encoded polypeptides was not induced at the bleaching temperature. It is concluded that protein synthesis in plastids declines during the initial phase of the temperature response in Euglena despite an overall increase in cellular protein synthesis and an increase in chlorophyll accumulation per cell.

  19. Vapor pressures of mixtures of CFC-114 with the potential replacement coolants C{sub 4}F{sub 10} and c-C{sub 4}F{sub 8}

    SciTech Connect

    Trowbridge, L.D.; Otey, M.G.

    1994-09-01

    The U.S. Enrichment Corporation`s production of isotopically enriched uranium depends solely on two plants which utilize the gaseous diffusion process. This process uses large quantities of CFC-114 as an evaporative coolant. CFC-114, however, will be phased out of production at the end of 1995 due to its potential to deplete stratospheric ozone. A search has been underway for substitutes for a number of years. The initial search (1988-89) for an ozone-friendly, commercially available, chemically compatible substitute yielded two candidates, FC-c318 (c-C{sub 4}F{sub 8}) and FC-3110 (C{sub 4}F{sub 10}). The intended mode of replacing coolant was to stage the new coolant into independent subsystems of the plants, so that some systems would continue to operate on CFC-114, and an increasing number would operate on the new coolant. During that changeover process, the possibility of coolant mixing arises in variety of scenarios. This work was intended to generate sufficient experimental information to be able to predict the vapor pressure of coolant mixtures over the range of operating conditions likely to be found in the diffusion plants. Specifically, vapor pressures were measured over the temperature range 322 to 355 K (120{degrees}F to 180{degrees}F) and over the full range of mole fractions for binary mixtures of CFC-114 with FC-3110, and of CFC-114 with FC-c318.

  20. Effects of initial temperature and tempering medium on thermal tempering of dental porcelains.

    PubMed

    Hojjatie, B; Anusavice, K J

    1993-03-01

    The objective of this study was to test the hypothesis that quenching of porcelain in silicone oil rather than in compressed air will significantly increase the flexure strength by reducing the potential for crack formation during transient cooling. A secondary hypothesis to be tested is that the initial tempering temperature can be reduced significantly below the porcelain maturing temperature of 982 degrees C but well above Tg without a decrease in strength. Opaque-body porcelain disks, 16 mm in diameter and 2 mm in thickness, with a thermal contraction mismatch (delta alpha) of -1.5, 0, and +3.2 ppm/degrees C were tempered from initial temperatures of 650, 750, 850, and 982 degrees C in silicone oil with kinematic viscosities of 50, 1000, and 5000 centistokes. Porcelain disks were also subjected to three cooling procedures in air: slow cooling in a furnace (SC), free convective cooling in a laboratory bench (FC), and tempering (T) by blasting the surface of body porcelain with air. The crack size induced by a Vickers microhardness indenter was measured within one minute after crack development. For determination of the influence of initial cooling temperature on biaxial flexure strength, six body porcelain disks (delta alpha = 0) were tempered in air from initial temperatures of 650, 750, 850, and 982 degrees C. The mean crack size of specimens tempered in oil was significantly smaller (p < or = 0.001) than that of specimens that were slowly-cooled or fast-cooled in air for all thermal contraction mismatch cases.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8450115

  1. Analysis of automobile radiator performance with ethylene glycol/water and propylene glycol/water coolants

    SciTech Connect

    Gollin, M.; Bjork, D.

    1996-12-31

    The heat transfer and hydraulic performance of the following coolants was examined in five automobile radiators in a wind tunnel: 100% water; 100% propylene glycol; 70/30 propylene glycol/water (volume); 50/50 propylene glycol/water (volume); 70/30 ethylene glycol/water (volume); 50/50 ethylene glycol water (volume). The results of these studies are presented to demonstrate the relative performance of these coolant mixtures in terms of heat transfer, coolant pressure drop and radiator effectiveness for a range of coolant and air flowrates. It is concluded that the most effective of the coolants in transferring heat in the test radiators was water, followed by 50/50 ethylene glycol/water, 50/50 propylene glycol/water, 70/30 ethylene glycol/water, 70/30 propylene glycol and, finally, 100% propylene glycol. There will be a negligible differences between the performance of a radiator using a 50/50 propylene glycol/water coolant and a 50/50 ethylene glycol/water coolant. It is estimated that, with 50/50 propylene glycol coolant replacing 50/50 ethylene glycol/water, the temperature of the coolant throughout the cooling loop will increase by approximately 5%. The effect that the flow regime (fully turbulent/transition/laminar) has upon the performance of a given radiator/coolant combination was found to be significant. The design of the coolant passages in radiators can affect the onset of fully turbulent flow in the coolant passages in a radiator.

  2. Effect of initial core temperature on hyperthermic hyperventilation during prolonged submaximal exercise in the heat.

    PubMed

    Tsuji, Bun; Honda, Yasushi; Fujii, Naoto; Kondo, Narihiko; Nishiyasu, Takeshi

    2012-01-01

    We investigated whether a core temperature threshold for hyperthermic hyperventilation is seen during prolonged submaximal exercise in the heat when core temperature before the exercise is reduced and whether the evoked hyperventilatory response is affected by altering the initial core temperature. Ten male subjects performed three exercise trials at 50% of peak oxygen uptake in the heat (37°C and 50% relative humidity) after altering their initial esophageal temperature (T(es)). Initial T(es) was manipulated by immersion for 25 min in water at 18°C (Precooling), 35°C (Control), or 40°C (Preheating). T(es) after the water immersion was significantly higher in the Preheating trial (37.5 ± 0.3°C) and lower in the Precooling trial (36.1 ± 0.3°C) than in the Control trial (36.9 ± 0.3°C). In the Precooling trial, minute ventilation (Ve) showed little change until T(es) reached 37.1 ± 0.4°C. Above this core temperature threshold, Ve increased linearly in proportion to increasing T(es). In the Control trial, Ve increased as T(es) increased from 37.0°C to 38.6°C after the onset of exercise. In the Preheating trial, Ve increased from the initially elevated levels of T(es) (from 37.6 to 38.6°C) and Ve. The sensitivity of Ve to increasing T(es) above the threshold for hyperventilation (the slope of the T(es)-Ve relation) did not significantly vary across trials (Precooling trial = 10.6 ± 5.9, Control trial = 8.7 ± 5.1, and Preheating trial = 9.2 ± 6.9 L·min(-1)·°C(-1)). These results suggest that during prolonged submaximal exercise at a constant workload in humans, there is a clear core temperature threshold for hyperthermic hyperventilation and that the evoked hyperventilatory response is unaffected by altering initial core temperature. PMID:21957164

  3. Deformation and failure of bulk metallic glasses under different initial temperatures

    NASA Astrophysics Data System (ADS)

    Li, J. C.; Chen, X. W.; Huang, F. L.

    2015-09-01

    Based on the coupled thermo-mechanical model, a constitutive model for bulk metallic glasses (BMGs), which is generalized to the multi-axial stress state and considers the effects of free volume, heat and hydrostatic stress, has been modified in the present paper. Besides, a failure criterion of critical free volume concentration is introduced based on the coalescence mechanism of free volume. The constitutive model as well as the failure criterion is implemented into the LS-DYNA commercial software by user material subroutine (UMAT). Then FEM simulations for different initial material temperatures are conducted and the evolutions of material parameter as well as corresponding macroscopic mechanical behaviour of material are analyzed. Relative analysis shows that the initial material temperature significantly affects the deformation and failure of material.

  4. Hematite natural crystals: non-linear initial susceptibility at low temperature

    NASA Astrophysics Data System (ADS)

    Guerrero Suarez, S.; Martín-Hernández, F.

    2016-04-01

    Several works have reported that hematite has non-linear initial susceptibility at room temperature, like pyrrhotite or titanomagnetite, but there is no explanation for the observed behaviours yet. This study sets out to determine which physical property (grain-size, foreign cations content, domain walls displacements) controls the initial susceptibility. The performed measurements include microprobe analysis to determine magnetic phases different to hematite; initial susceptibility (300 K); hysteresis loops, SIRM and backfield curves at 77 K and 300 K to calculate magnetic parameters and minor loops at 77 K, to analyze initial susceptiblity and magnetization behaviours below Morin transition. The magnetic moment study at low temperatura is completed with measurements of Zero Field Cooled- Field Cooled (ZFC-FC) and AC-susceptibility in a range from 5-300 K. The minor loops show that the non-linearity of initial susceptibility is closely related to Barkhausen jumps. Because of initial magnetic susceptibility is controlled by domain structure it is difficult to establish a mathematical model to separate magnetic subfabrics in hematite-bearing rocks.

  5. The effect of initial temperature on flame acceleration and deflagration-to-detonation transition phenomenon

    SciTech Connect

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.; Finfrock, C.; Gerlach, L.; Tagawa, H.; Malliakos, A.

    1998-05-01

    The High-Temperature Combustion Facility at BNL was used to conduct deflagration-to-detonation transition (DDT) experiments. Periodic orifice plates were installed inside the entire length of the detonation tube in order to promote flame acceleration. The orifice plates are 27.3-cm-outer diameter, which is equivalent to the inner diameter of the tube, and 20.6-cm-inner diameter. The detonation tube length is 21.3-meters long, and the spacing of the orifice plates is one tube diameter. A standard automobile diesel engine glow plug was used to ignite the test mixture at one end of the tube. Hydrogen-air-steam mixtures were tested at a range of temperatures up to 650K and at an initial pressure of 0.1 MPa. In most cases, the limiting hydrogen mole fraction which resulted in DDT corresponded to the mixture whose detonation cell size, {lambda}, was equal to the inner diameter of the orifice plate, d (e.g., d/{lambda}=1). The only exception was in the dry hydrogen-air mixtures at 650K where the DDT limit was observed to be 11 percent hydrogen, corresponding to a value of d/{lambda} equal to 5.5. For a 10.5 percent hydrogen mixture at 650K, the flame accelerated to a maximum velocity of about 120 mIs and then decelerated to below 2 mIs. By maintaining the first 6.1 meters of the vessel at the ignition end at 400K, and the rest of the vessel at 650K, the DDT limit was reduced to 9.5 percent hydrogen (d/{lambda}=4.2). This observation indicates that the d/{lambda}=1 DDT limit criteria provides a necessary condition but not a sufficient one for the onset of DDT in obstacle laden ducts. In this particular case, the mixture initial condition (i.e., temperature) resulted in the inability of the mixture to sustain flame acceleration to the point where DDT could occur. It was also observed that the distance required for the flame to accelerate to the point of detonation initiation, referred to as the run-up distance, was found to be a function of both the hydrogen mole fraction

  6. Turbulent Dispersion of Film Coolant in a Turbine Vane Cascade

    NASA Astrophysics Data System (ADS)

    Yapa, Sayuri; Elkins, Christopher; Eaton, John

    2012-11-01

    Gas turbine engines operate at peak temperatures in excess of the material limits because the high pressure turbine nozzles and buckets are film cooled. The nozzle vanes of the first stage turbine use the most cooling air because they are exposed directly to the high temperature combustor exhaust. Existing turbine analysis assumes a uniform temperature at the rotor inlet. However, the coolant does not mix completely with the mainstream flow before impinging on the turbine rotor, and the coolant streaks create variations in temperature along the leading edge of the downstream turbine blades. 3D velocity and concentration measurements are made using magnetic resonance (MR) imaging techniques to study turbulent mixing in a realistic film-cooled nozzle vane cascade. A scalar mixing analogy for thermal diffusion is used in which a chemical contaminant plays the role of temperature. In a typical experiment, the mainstream flow is water and the film coolant is a copper sulfate solution. The concentration of copper sulfate measured anywhere in the flow is a surrogate for normalized temperature. The turbulent scalar diffusivity in the scalar transport equation can be estimated from the MR data and used to improve computational fluid dynamics models. Army Research Office.

  7. Transcriptome Analysis of the Initial Stage of Acute WSSV Infection Caused by Temperature Change

    PubMed Central

    Sun, Yumiao; Li, Fuhua; Sun, Zheng; Zhang, Xiaojun; Li, Shihao; Zhang, Chengsong; Xiang, Jianhai

    2014-01-01

    White spot syndrome virus (WSSV) is the most devastating virosis threatening the shrimp culture industry worldwide. Variations of environmental factors in shrimp culture ponds usually lead to the outbreak of white spot syndrome (WSS). In order to know the molecular mechanisms of WSS outbreak induced by temperature variation and the biological changes of the host at the initial stage of WSSV acute infection, RNA-Seq technology was used to analyze the differentially expressed genes (DEGs) in shrimp with a certain amount of WSSV cultured at 18°C and shrimp whose culture temperature were raised to 25°C. To analyze whether the expression changes of the DEGs were due to temperature rising or WSSV proliferation, the expression of selected DEGs was analyzed by real-time PCR with another shrimp group, namely Group T, as control. Group T didn’t suffer WSSV infection but was subjected to temperature rising in parallel. At the initial stage of WSSV acute infection, DEGs related to energy production were up-regulated, whereas most DEGs related to cell cycle and positive regulation of cell death and were down-regulated. Triose phosphate isomerase, enolase and alcohol dehydrogenase involved in glycosis were up-regulated, while pyruvate dehydrogenase, citrate synthase and isocitrate dehydrogenase with NAD as the coenzyme involved in TCA pathway were down-regulated. Also genes involved in host DNA replication, including DNA primase, DNA topoisomerase and DNA polymerase showed down-regulated expression. Several interesting genes including crustin genes, acting binding or inhibiting protein genes, a disintegrin and metalloproteinase domain-containing protein 9 (ADAM9) gene and a GRP 78 gene were also analyzed. Understanding the interactions between hosts and WSSV at the initial stage of acute infection will not only help to get a deep insight into the pathogenesis of WSSV but also provide clues for therapies. PMID:24595043

  8. Effect of Initial Mixture Temperature on Flame Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L

    1952-01-01

    Flame speeds based on the outer edge of the shadow cast by the laminar Bunsen cone were determined as functions of composition for methane-air mixtures at initial mixture temperatures ranging from -132 degrees to 342 degrees c and for propane-air and ethylene-air mixtures at initial mixture temperatures ranging from -73 degrees to 344 degrees c. The data showed that maximum flame speed increased with temperature at an increasing rate. The percentage change in flame speed with change in initial temperature for the three fuels followed the decreasing order, methane, propane, and ethylene. Empirical equations were determined for maximum flame speed as a function of initial temperature over the temperature range covered for each fuel. The observed effect of temperature on flame speed for each of the fuels was reasonably well predicted by either the thermal theory as presented by Semenov or the square-root law of Tanford and Pease.

  9. INHIBITING THE POLYMERIZATION OF NUCLEAR COOLANTS

    DOEpatents

    Colichman, E.L.

    1959-10-20

    >The formation of new reactor coolants which contain an additive tbat suppresses polymerization of the primary dissoclation free radical products of the pyrolytic and radiation decomposition of the organic coolants is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to 5% of a powdered metal hydride chosen from the group consisting of the group IIA and IVA dispersed in the hydrocarbon.

  10. Organic coolant for ARIES-III

    SciTech Connect

    Sze, D.K. ); Sviatoslavsky, I.; Sawan, M. ); Gierszewski, P. ); Hollies, R. ); Sharafat, S. ); Herring, S. )

    1991-04-01

    ARIES-III is a D-He{sub 3} reactor design study. It is found that the organic coolant is well suited for the D-He{sub 3} reactor. This paper discusses the unique features of the D-He{sub 3} reactor, and the reason that the organic coolant is compatible with those features. The problems associated with the organic coolant are also discussed. 8 refs., 2 figs., 6 tabs.

  11. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

    PubMed Central

    Bang, W.; Albright, B. J.; Bradley, P. A.; Vold, E. L.; Boettger, J. C.; Fernández, J. C.

    2016-01-01

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly with temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. These simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement. PMID:27405664

  12. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

    NASA Astrophysics Data System (ADS)

    Bang, W.; Albright, B. J.; Bradley, P. A.; Vold, E. L.; Boettger, J. C.; Fernández, J. C.

    2016-07-01

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly with temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. These simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.

  13. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

    DOE PAGESBeta

    Bang, Woosuk; Albright, Brian James; Bradley, Paul Andrew; Vold, Erik Lehman; Boettger, Jonathan Carl; Fernández, Juan Carlos

    2016-07-12

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly withmore » temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. In conclusion, these simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.« less

  14. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter.

    PubMed

    Bang, W; Albright, B J; Bradley, P A; Vold, E L; Boettger, J C; Fernández, J C

    2016-01-01

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1-100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly with temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. These simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement. PMID:27405664

  15. Prototypic Thermal-Hydraulic Experiment in NRU to Simulate Loss-of-Coolant Accidents

    SciTech Connect

    Mohr, C. L.; Hesson, G. M.; Russcher, G. E.; Marsh, R. K.; King, L. L.; Wildung, N. J.; Rausch, W. N.; Bennett, W. D.

    1981-04-01

    Quick-look test results are reported for the initial test series of the Loss-of-Coolant Accident (LOCA) Simulation in the National Research Universal {NRU) test program, conducted by Pacific Northwest Laboratory (PNL) for the U.S. Nuclear Regulatory Commission (NRC). This test was devoted to evaluating the thermal-hydraulic characteristics of a full-length light water reactor (LWR) fuel bundle during the heatup, reflood, and quench phases of a LOCA. Experimental results from 28 tests cover reflood rates of 0.74 in./sec to 11 in./sec and delay times to initiate reflood of 3 sec to 66 sec. The results indicate that current analysis methods can predict peak temperatures within 10% and measured quench times for the bundle were significantly less than predicted. For reflood rates of 1 in./sec where long quench times were predicted (>2000 sec}, measured quench times of 200 sec were found.

  16. Engine coolant compatibility with the nonmetals found in automotive cooling systems

    SciTech Connect

    Greaney, J.P.; Smith, R.A.

    1999-08-01

    High temperature, short term immersion testing was used to determine the impact of propylene and ethylene glycol base coolants on the physical properties of a variety of elastomeric and thermoplastic materials found in automotive cooling systems. The materials tested are typically used in cooling system hoses, radiator end tanks, and water pump seals. Traditional phosphate or borate-buffered silicated coolants as well as extended-life organic acid formulations were included. A modified ASTM protocol was used to carry out the testing both in the laboratory and at an independent testing facility. Post-test fluid chemistry including an analysis of any solids which may have formed is also reported. Coolant impact on elastomer integrity as well as elastomer-induced changes in fluid chemistry were found to be independent of the coolant`s glycol base.

  17. Role of initial state and final quench temperature on aging properties in phase-ordering kinetics

    NASA Astrophysics Data System (ADS)

    Corberi, Federico; Villavicencio-Sanchez, Rodrigo

    2016-05-01

    We study numerically the two-dimensional Ising model with nonconserved dynamics quenched from an initial equilibrium state at the temperature Ti≥Tc to a final temperature Tf below the critical one. By considering processes initiating both from a disordered state at infinite temperature Ti=∞ and from the critical configurations at Ti=Tc and spanning the range of final temperatures Tf∈[0 ,Tc[ we elucidate the role played by Ti and Tf on the aging properties and, in particular, on the behavior of the autocorrelation C and of the integrated response function χ . Our results show that for any choice of Tf, while the autocorrelation function exponent λC takes a markedly different value for Ti=∞ [λC(Ti=∞ ) ≃5 /4 ] or Ti=Tc [λC(Ti=Tc) ≃1 /8 ] the response function exponents are unchanged. Supported by the outcome of the analytical solution of the solvable spherical model we interpret this fact as due to the different contributions provided to autocorrelation and response by the large-scale properties of the system. As changing Tf is considered, although this is expected to play no role in the large-scale and long-time properties of the system, we show important effects on the quantitative behavior of χ . In particular, data for quenches to Tf=0 are consistent with a value of the response function exponent λχ=1/2 λC(Ti=∞ ) =5 /8 different from the one [λχ∈(0.5 -0.56 ) ] found in a wealth of previous numerical determinations in quenches to finite final temperatures. This is interpreted as due to important preasymptotic corrections associated to Tf>0 .

  18. Temperature and initial curvature effects in low-density panel flutter

    NASA Technical Reports Server (NTRS)

    Resende, Hugo B.

    1992-01-01

    The panel flutter phenomenon is studied assuming free-molecule flow. This kind of analysis is relevant in the case of hypersonic flight vehicles traveling at high altitudes, especially in the leeward portion of the vehicle. In these conditions the aerodynamic shear can be expected to be considerably larger than the pressure at a given point, so that the effects of such a loading are incorporated into the structural model. Both the pressure and shear loadings are functions of the panel temperature, which can lead to great variations on the location of the stability boundaries for parametric studies. Different locations can, however, be 'collapsed' onto one another by using as ordinate an appropriately normalized dynamic pressure parameter. This procedure works better for higher values of the panel temperature for a fixed undisturbed flow temperature. Finally, the behavior of the system is studied when the panel has some initial curvature. This leads to the conclusion that it may be unrealistic to try to distinguish between a parabolic or sinusoidal initial shape.

  19. Controlling the velocity of jumping nanodroplets via their initial shape and temperature

    SciTech Connect

    Fuentes-Cabrera, Miguel A; Rhodes, Bradley H; Baskes, Mike I.; Terrones Maldonado, Humberto; Fowlkes, Jason Davidson; Simpson, Michael L; Rack, Philip D

    2011-01-01

    Controlling the movement of nanoscale objects is a significant goal of nanotechnology. Dewetting-induced ejection of nanodroplets could provide another means of achieving that goal. Molecular dynamics simulations were used to investigate the dewetting-induced ejection of nanoscale liquid copper nanostructures that were deposited on a graphitic substrate. Nanostructures in the shape of a circle, square, equilateral, and isosceles triangle dewet and form nanodroplets that are ejected from the substrate with a velocity that depends on the initial shape and temperature. The dependence of the ejected velocity on shape is ascribed to the temporal asymmetry of the mass coalescence during the droplet formation; the dependence on temperature is ascribed to changes in the density and viscosity. The results suggest that dewetting induced by nanosecond laser pulses could be used to control the velocity of ejected nanodroplets.

  20. Combustion and pressure wave interaction in enclosed mixtures initiated by temperature nonuniformities

    SciTech Connect

    Weber, H.J.; Mack, A.; Roth, P. . Inst. fuer Verbrennung und Gasdynamik)

    1994-06-01

    The dynamics of one-dimensional combustion waves originating from hot-spot ignition was studied numerically by solving the corresponding conservation equations for mass, species, energy, and momentum. The mathematical model included a multispecies transport model and a detailed reaction mechanism. The numerical solution of the time-dependent conservation equations was based on the method of lines and on a dynamic adaptive grid technique. Due to the stiffness of the resulting system of ordinary differential equations, the BDF-code DASSL was used to integrate the equations. The results of the simulations show that the interaction of combustion and pressure wave can lead to deflagration to detonation transition. Depending on the temperature levels and the shape of the temperature nonuniformity, ordinary flame propagation, deflagration to detonation transition or to deflagration waves, depending on the initial conditions.

  1. Controlling the Velocity of Jumping Nanodroplets Via Their Initial Shape and Temperature

    SciTech Connect

    Kent, Paul R

    2011-01-01

    Controlling the movement of nanoscale objects is a significant goal of nanotechnology. Dewetting-induced ejection of nanodroplets could provide another means of achieving that goal. Molecular dynamics simulations were used to investigate the dewetting-induced ejection of nanoscale liquid copper nanostructures that were deposited on a graphitic substrate. Nanostructures in the shape of a circle, square, equilateral, and isosceles triangle dewet and form nanodroplets that are ejected from the substrate with a velocity that depends on the initial shape and temperature. The dependence of the ejected velocity on shape is ascribed to the temporal asymmetry of the mass coalescence during the droplet formation; the dependence on temperature is ascribed to changes in the density and viscosity. The results suggest that dewetting induced by nanosecond laser pulses could be used to control the velocity of ejected nanodroplets.

  2. Corrosion of structural materials by lead-based reactor coolants.

    SciTech Connect

    Abraham, D. P.; Leibowitz, L.; Maroni, V. A.; McDeavitt, S. M.; Raraz, A. G.

    2000-11-16

    Advanced nuclear reactor design has, in recent years, focused increasingly on the use of heavy-liquid-metal coolants, such as lead and lead-bismuth eutectic. Similarly, programs on accelerator-based transmutation systems have also considered the use of such coolants. Russian experience with heavy-metal coolants for nuclear reactors has lent credence to the validity of this approach. Of significant concern is the compatibility of structural materials with these coolants. We have used a thermal convection-based test method to allow exposure of candidate materials to molten lead and lead-bismuth flowing under a temperature gradient. The gradient was deemed essential in evaluating the behavior of the test materials in that should preferential dissolution of components of the test material occur we would expect dissolution in the hotter regions and deposition in the colder regions, thus promoting material transport. Results from the interactions of a Si-rich mild steel alloy, AISI S5, and a ferritic-martensitic stainless steel, HT-9, with the molten lead-bismuth are presented.

  3. Coolant Design System for Liquid Propellant Aerospike Engines

    NASA Astrophysics Data System (ADS)

    McConnell, Miranda; Branam, Richard

    2015-11-01

    Liquid propellant rocket engines burn at incredibly high temperatures making it difficult to design an effective coolant system. These particular engines prove to be extremely useful by powering the rocket with a variable thrust that is ideal for space travel. When combined with aerospike engine nozzles, which provide maximum thrust efficiency, this class of rockets offers a promising future for rocketry. In order to troubleshoot the problems that high combustion chamber temperatures pose, this research took a computational approach to heat analysis. Chambers milled into the combustion chamber walls, lined by a copper cover, were tested for their efficiency in cooling the hot copper wall. Various aspect ratios and coolants were explored for the maximum wall temperature by developing our own MATLAB code. The code uses a nodal temperature analysis with conduction and convection equations and assumes no internal heat generation. This heat transfer research will show oxygen is a better coolant than water, and higher aspect ratios are less efficient at cooling. This project funded by NSF REU Grant 1358991.

  4. Equation of state and initial temperature of quark gluon plasma at RHIC

    NASA Astrophysics Data System (ADS)

    Csanád, Máté; Májer, Imre

    2012-08-01

    In gold-gold collisions of the Relativistic Heavy Ion Collider a perfect fluid of strongly interacting quark gluon plasma (sQGP) is created. The time evolution of this fluid can be described by hydrodynamical models. After an expansion, hadrons are created during the freeze-out period. Their distribution reveals information about the final state. To investigate the time evolution one needs to analyze penetrating probes: e.g. direct photon observations. In this paper we analyze a 1+3 dimensional solution of relativistic hydrodynamics. We calculate momentum distribution, azimuthal asymmetry and momentum correlations of direct photons. Based on earlier fits to hadronic spectra, we compare photon calculations to measurements to determine the equations of state and the initial temperature of sQGP. We find that the initial temperature in the center of the fireball is 507±12 MeV, while for the sound speed we get c s=0.36±0.02. We also estimate a systematic error of these results. We find that the measured azimuthal asymmetry is also compatible with this model. We also predict a photon source that is significantly larger in the out direction than in the side direction.

  5. Equation of state and initial temperature of quark gluon plasma at RHIC

    NASA Astrophysics Data System (ADS)

    Csanád, Máté; Májer, Imre

    2012-08-01

    In gold-gold collisions of the Relativistic Heavy Ion Collider a perfect fluid of strongly interacting quark gluon plasma (sQGP) is created. The time evolution of this fluid can be described by hydrodynamical models. After an expansion, hadrons are created during the freeze-out period. Their distribution reveals information about the final state. To investigate the time evolution one needs to analyze penetrating probes: e.g. direct photon observations. In this paper we analyze a 1+3 dimensional solution of relativistic hydrodynamics. We calculate momentum distribution, azimuthal asymmetry and momentum correlations of direct photons. Based on earlier fits to hadronic spectra, we compare photon calculations to measurements to determine the equations of state and the initial temperature of sQGP. We find that the initial temperature in the center of the fireball is 507±12 MeV, while for the sound speed we get c s =0.36±0.02. We also estimate a systematic error of these results. We find that the measured azimuthal asymmetry is also compatible with this model. We also predict a photon source that is significantly larger in the out direction than in the side direction.

  6. Numerical simulation of PWR response to a small break LOCA (loss-of-coolant accident) with reactor coolant pumps operating

    SciTech Connect

    Adams, J.P.; Dobbe, C.A.; Bayless, P.D.

    1986-01-01

    Calculations have been made of the response of pressurized water reactors (PWRs) during a small-break, loss-of-coolant accident with the reactor coolant pumps (RCPs) operating. This study was conducted, as part of a comprehensive project, to assess the relationship between measurable RCP parameters, such as motor power or current, and fluid density, both local (at the RCP inlet) and global (average reactor coolant system). Additionally, the efficacy of using these RCP parameters, together with fluid temperature, to identify an off-nominal transient as either a LOCA, a heatup transient, or a cooldown transient and to follow recovery from the transient was assessed. The RELAP4 and RELAP5 computer codes were used with three independent sets of RCP, two-phase degradation multipliers. These multipliers were based on data obtained in two-phase flow conditions for the Semiscale, LOFT, and Creare/Combustion Engineering (CE)/Electric Power Research Institute (EPRI) pumps, respectively. Two reference PWRs were used in this study: Zion, a four-loop, 1100-MWe, Westinghouse plant operated by Commonwealth Edison Co. in Zion, Illinois and Bellefonte, a two-by-four loop, 1213 MWe, Babcock and Wilcox designed plant being built by the Tennessee Valley Authority in Scottsboro, Alabama. The results from this study showed that RCP operation resulted in an approximately homogeneous reactor coolant system and that this result was independent of reference plant, computer code, or two-phase RCP head degradation multiplier used in the calculation.

  7. Cleaning of uranium vs machine coolant formulations

    SciTech Connect

    Cristy, S.S.; Byrd, V.R.; Simandl, R.F.

    1984-10-01

    This study compares methods for cleaning uranium chips and the residues left on chips from alternate machine coolants based on propylene glycol-water mixtures with either borax, ammonium tetraborate, or triethanolamine tetraborate added as a nuclear poison. Residues left on uranium surfaces machined with perchloroethylene-mineral oil coolant and on surfaces machined with the borax-containing alternate coolant were also compared. In comparing machined surfaces, greater chlorine contamination was found on the surface of the perchloroethylene-mineral oil machined surfaces, but slightly greater oxidation was found on the surfaces machined with the alternate borax-containing coolant. Overall, the differences were small and a change to the alternate coolant does not appear to constitute a significant threat to the integrity of machined uranium parts.

  8. Solar receiver protection means and method for loss of coolant flow

    DOEpatents

    Glasgow, L.E.

    1980-11-24

    An apparatus and method are disclosed for preventing a solar receiver utilizing a flowing coolant liquid for removing heat energy therefrom from overheating after a loss of coolant flow. Solar energy is directed to the solar receiver by a plurality of reflectors which rotate so that they direct solar energy to the receiver as the earth rotates. The apparatus disclosed includes a first storage tank for containing a first predetermined volume of the coolant and a first predetermined volume of gas at a first predetermined pressure. The first storage tank includes an inlet and outlet through which the coolant can enter and exit. The apparatus also includes a second storage tank for containing a second predetermined volume of the coolant and a second predetermined volume of the gas at a second predetermined pressure, the second storage tank having an inlet through which the coolant can enter. The first and second storage tanks are in fluid communication with each other through the solar receiver. The first and second predetermined coolant volumes, the first and second gas volumes, and the first and second predetermined pressures are chosen so that a predetermined volume of the coolant liquid at a predetermined rate profile will flow from the first storage tank through the solar receiver and into the second storage tank. Thus, in the event of a power failure so that coolant flow ceases and the solar reflectors stop rotating, a flow rate maintained by the pressure differential between the first and second storage tanks will be sufficient to maintain the coolant in the receiver below a predetermined upper temperature until the solar reflectors become defocused with respect to the solar receiver due to the earth's rotation.

  9. Solar receiver protection means and method for loss of coolant flow

    DOEpatents

    Glasgow, Lyle E.

    1983-01-01

    An apparatus and method for preventing a solar receiver (12) utilizing a flowing coolant liquid for removing heat energy therefrom from overheating after a loss of coolant flow. Solar energy is directed to the solar receiver (12) by a plurality of reflectors (16) which rotate so that they direct solar energy to the receiver (12) as the earth rotates. The apparatus disclosed includes a first storage tank (30) for containing a first predetermined volume of the coolant and a first predetermined volume of gas at a first predetermined pressure. The first storage tank (30) includes an inlet and outlet through which the coolant can enter and exit. The apparatus also includes a second storage tank (34) for containing a second predetermined volume of the coolant and a second predetermined volume of the gas at a second predetermined pressure, the second storage tank (34) having an inlet through which the coolant can enter. The first and second storage tanks (30) and (34) are in fluid communication with each other through the solar receiver (12). The first and second predetermined coolant volumes, the first and second gas volumes, and the first and second predetermined pressures are chosen so that a predetermined volume of the coolant liquid at a predetermined rate profile will flow from the first storage tank (30) through the solar receiver (12) and into the second storage tank (34). Thus, in the event of a power failure so that coolant flow ceases and the solar reflectors (16) stop rotating, a flow rate maintained by the pressure differential between the first and second storage tanks (30) and (34) will be sufficient to maintain the coolant in the receiver (12) below a predetermined upper temperature until the solar reflectors (16) become defocused with respect to the solar receiver (12) due to the earth's rotation.

  10. Micromechanical modeling of temperature-dependent initiation fracture toughness in advanced aluminum alloys

    SciTech Connect

    Haynes, M.J.; Somerday, B.P.; Gangloff, R.P.; Lach, C.L.

    1997-12-31

    The temperature dependence of the plane-strain initiation fracture toughness (K{sub JICi}) is modeled micromechanically for a variety of advanced aluminum alloys that fail by microvoid processes. Materials include precipitation-hardened ingot metallurgy, spray formed, submicron-grain-size powder metallurgy, and metal-matrix composite alloys. A critical-plastic-strain-controlled model, employing tensile yield strength, elastic modulus, work hardening, and reduction of area measurements, successfully predicts K{sub JICi} versus temperature for eight alloys, providing a strong confirmation of this approach. Modeling shows that K{sub JICi} is controlled by the interplay between the temperature dependencies of the intrinsic failure locus {bar {var_epsilon}}{sub f}{sup p}({sigma}{sub m}/{sigma}{sub fl}) and the crack-tip stress/strain fields governed by alloy flow properties. Uncertainties in {bar {var_epsilon}}{sub f}{sup p}({sigma}{sub m}/{sigma}{sub fl}), as well as the critical distance (volume) for crack-tip damage evolution, hinder absolute predictions of K{sub JICi}. Critical distance (calculated from the model) correlates with the nearest-neighbor spacing of void-nucleating particles and with the extent of primary void growth determined from quantitative fractography. These correlations suggest a means to predict absolute plane-strain fracture toughness.

  11. Heat-transfer dynamics during cryogen spray cooling of substrate at different initial temperatures.

    PubMed

    Jia, Wangcun; Aguilar, Guillermo; Wang, Guo-Xiang; Nelson, J Stuart

    2004-12-01

    Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatologic therapy. However, the dominant mechanisms of heat transfer during the transient cooling process are incompletely understood. The objective of this study is to elucidate the physics of CSC by measuring the effect of initial substrate temperature (T0) on cooling dynamics. Cryogen was delivered by a straight-tube nozzle onto a skin phantom. A fast-response thermocouple was used to record the phantom temperature changes before, during and after the cryogen spray. Surface heat fluxes (q") and heat-transfer coefficients (h) were computed using an inverse heat conduction algorithm. The maximum surface heat flux (q"max) was observed to increase with T0. The surface temperature corresponding to q"max also increased with T0 but the latter has no significant effect on h. It is concluded that heat transfer between the cryogen spray and skin phantom remains in the nucleate boiling region even if T0 is 80 degrees C. PMID:15656278

  12. Effect of Initial Temperature Treatment on Phytochemicals and Antioxidant Activity of Azadirachta indica A. Juss.

    PubMed

    Vats, Sharad

    2016-02-01

    The present study was undertaken to evaluate the effect of initial temperature treatment on phytochemical and antioxidant potential of commercially important plant Azadirachta indica A. Juss. The leaves were differentially treated after harvest at temperatures 4, -20, and 110 °C and at room temperature, separately. It was found that a quick drying process at 110 °C followed by air-drying helped in maximum retention of bioactive compounds and antioxidant activity, which was significantly higher than other processing methods. Correlation analysis revealed that total phenolic content (TPC) and total flavonoid content (TFC) can be a measure to assess the antioxidant potential using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays. Nitric oxide scavenging assay (NOSA) was insignificantly related to DPPH and FRAP. Also, FRAP and DPPH can be a predictive assay for each other, but not with NOSA. Thus, a quick drying process at 110 °C using an oven can be a cost-effective venture, especially in developing countries, for retaining the nutritive value and antioxidant activity of A. indica. PMID:26467740

  13. INITIAL RESULTS FROM INVESTIGATIONS TO ENHANCE THE PERFORMANCE OF HIGH TEMPERATURE IRRADIATION-RESISTANT THERMOCOUPLES

    SciTech Connect

    Crepeau, John; Rempe, Joy; Wilkins, S. Curtis; Knudson, Darrell L.; Condie, Keith G.; Daw, Joshua

    2007-04-01

    New fuel, cladding, and structural materials offer the potential for safer and more economic energy from existing reactor and advanced nuclear reactor designs. However, insufficient data are available to characterize these materials in high temperature, radiation conditions. To evaluate candidate material performance, robust instrumentation is needed that can survive these conditions. However, traditional thermocouples either drift due to degradation at high temperatures (above 1100 °C) or due to transmutation of thermocouple components. Thermocouples are needed which can withstand both high temperature and high radiation environments. To address this instrumentation need, the Idaho National Laboratory (INL) recently developed the design and evaluated the performance of a high temperature radiation-resistant thermocouple that contains commercially-available alloys of molybdenum and niobium (Rempe, 2006). Candidate thermocouple component materials were first identified based on their ability to withstand high temperature and radiation. Then, components were selected based on data obtained from materials interaction tests, ductility investigations, and resolution evaluations. Results from long duration (over 4000 hours) tests at high temperatures (up to 1400 °C) and thermal cycling tests demonstrate the stability and reliability of the INL-developed design. Tests in INL’s Advanced Test Reactor (ATR) are underway to demonstrate the in-pile performance of these thermocouples. However, several options have been identified that could further enhance the lifetime and reliability of the INL-developed thermocouples, allowing their use in higher temperature applications (up to at least 1700 °C). A joint University of Idaho (UI) and INL University Nuclear Energy Research Initiative (UNERI) is underway to investigate these options and ultimately, provide recommendations for an enhanced thermocouple design. This paper presents preliminary results from this UI/INL effort

  14. How does low temperature coupled with different pressures affect initiation mechanisms and subsequent decompositions in nitramine explosive HMX?

    PubMed

    Wu, Qiong; Xiong, Guolin; Zhu, Weihua; Xiao, Heming

    2015-09-21

    We have performed ab initio molecular dynamics simulations to study coupling effects of temperature (534-873 K) and pressure (1-20 GPa) on the initiation mechanisms and subsequent chemical decompositions of nitramine explosive 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). A new initiation decomposition mechanism of HMX was found to be the unimolecular C-H bond breaking, and this mechanism was independent of the coupling effects of different temperatures and pressures. The formed hydrogen radicals could promote subsequent decompositions of HMX. Subsequent decompositions were very sensitive to the pressure at low temperatures (534 and 608 K), while the temperature became the foremost factor that affected the decomposition at a high temperature (873 K) instead of the pressure. Our study may provide a new insight into understanding the coupling effects of the temperature and pressure on the initiation decomposition mechanisms of nitramine explosives. PMID:26264421

  15. SCC Initiation in Alloy 600 Heat Affected Zones Exposed to High Temperature Water

    SciTech Connect

    E Richey; DS Morton; RA Etien; GA Young; RB Bucinell

    2006-11-03

    Studies have shown that grain boundary chromium carbides improve the stress corrosion cracking (SCC) resistance of nickel based alloys exposed to high temperature, high purity water. However, thermal cycles from welding can significantly alter the microstructure of the base material near the fusion line. In particular, the heat of welding can solutionize grain boundary carbides and produce locally high residual stresses and strains, reducing the SCC resistance of the Alloy 600 type material in the heat affected zone (HAZ). Testing has shown that the SCC growth rate in Alloy 600 heat affected zone samples can be {approx}30x faster than observed in the Alloy 600 base material under identical testing conditions due to fewer intergranular chromium rich carbides and increased plastic strain in the HAZ [1, 2]. Stress corrosion crack initiation tests were conducted on Alloy 600 HAZ samples at 360 C in hydrogenated, deaerated water to determine if these microstructural differences significantly affect the SCC initiation resistance of Alloy 600 heat affected zones compared to the Alloy 600 base material. Alloy 600 to EN82H to Alloy 600 heat-affected-zone (HAZ) specimens where fabricated from an Alloy 600 to Alloy 600 narrow groove weld with EN82H filler metal. The approximate middle third of the specimen gauge region was EN82H such that each specimen had two HAZ regions. Tests were conducted with in-situ monitored smooth tensile specimens under a constant load, and a direct current electric potential drop was used for in-situ detection of SCC. Test results suggest that the SCC initiation resistance of Alloy 600 and its weld metal follows the following order: EN82H > Alloy 600 HAZ > Alloy 600. The high SCC initiation resistance observed to date in Alloy 600 heat affected zones compared to wrought Alloy 600 is unexpected based on the microstructure of HAZ versus wrought material and based on prior SCC growth rate studies. The observed behavior for the HAZ specimens is likely

  16. Study of ozone-initiated limonene reaction products by low temperature plasma ionization mass spectrometry.

    PubMed

    Nørgaard, Asger W; Vibenholt, Anni; Benassi, Mario; Clausen, Per Axel; Wolkoff, Peder

    2013-07-01

    Limonene and its ozone-initiated reaction products were investigated in situ by low temperature plasma (LTP) ionization quadrupole time-of-flight (QTOF) mass spectrometry. Helium was used as discharge gas and the protruding plasma generated ~850 ppb ozone in front of the glass tube by reaction with the ambient oxygen. Limonene applied to filter paper was placed in front of the LTP afterglow and the MS inlet. Instantly, a wide range of reaction products appeared, ranging from m/z 139 to ca. 1000 in the positive mode and m/z 115 to ca. 600 in the negative mode. Key monomeric oxidation products including levulinic acid, 4-acetyl-1-methylcyclohexene, limonene oxide, 3-isopropenyl-6-oxo-heptanal, and the secondary ozonide of limonene could be identified by collision-induced dissociation. Oligomeric products ranged from the nonoxidized dimer of limonene (C20H30) and up to the hexamer with 10 oxygen atoms (C60H90O10). The use of LTP for in situ ozonolysis and ionization represents a new and versatile approach for the assessment of ozone-initiated terpene chemistry. PMID:23666602

  17. Study of Ozone-Initiated Limonene Reaction Products by Low Temperature Plasma Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Nørgaard, Asger W.; Vibenholt, Anni; Benassi, Mario; Clausen, Per Axel; Wolkoff, Peder

    2013-07-01

    Limonene and its ozone-initiated reaction products were investigated in situ by low temperature plasma (LTP) ionization quadrupole time-of-flight (QTOF) mass spectrometry. Helium was used as discharge gas and the protruding plasma generated ~850 ppb ozone in front of the glass tube by reaction with the ambient oxygen. Limonene applied to filter paper was placed in front of the LTP afterglow and the MS inlet. Instantly, a wide range of reaction products appeared, ranging from m/ z 139 to ca. 1000 in the positive mode and m/ z 115 to ca. 600 in the negative mode. Key monomeric oxidation products including levulinic acid, 4-acetyl-1-methylcyclohexene, limonene oxide, 3-isopropenyl-6-oxo-heptanal, and the secondary ozonide of limonene could be identified by collision-induced dissociation. Oligomeric products ranged from the nonoxidized dimer of limonene (C20H30) and up to the hexamer with 10 oxygen atoms (C60H90O10). The use of LTP for in situ ozonolysis and ionization represents a new and versatile approach for the assessment of ozone-initiated terpene chemistry.

  18. Bi-coolant flat plate solar collector

    NASA Astrophysics Data System (ADS)

    Chon, W. Y.; Green, L. L.

    The feasibility study of a flat plate solar collector which heats air and water concurrently or separately was carried out. Air flows above the collector absorber plate, while water flows in tubes soldered or brazed beneath the plate. The collector efficiencies computed for the flow of both air and water are compared with those for the flow of a single coolant. The results show that the bi-coolant collector efficiency computed for the entire year in Buffalo, New York is higher than the single-coolant collector efficiency, although the efficiency of the water collector is higher during the warmer months.

  19. Coolant mass flow equalizer for nuclear fuel

    DOEpatents

    Betten, Paul R.

    1978-01-01

    The coolant mass flow distribution in a liquid metal cooled reactor is enhanced by restricting flow in sub-channels defined in part by the peripheral fuel elements of a fuel assembly. This flow restriction, which results in more coolant flow in interior sub-channels, is achieved through the use of a corrugated liner positioned between the bundle of fuel elements and the inner wall of the fuel assembly coolant duct. The corrugated liner is expandable to accommodate irradiation induced growth of fuel assembly components.

  20. Overall reaction concept in premixed, laminar, steady-state flames. II. Initial temperatures and pressures. Final technical report

    SciTech Connect

    Coffee, T.P.; Kotlar, A.J.; Miller, M.S.

    1984-11-01

    In a previous report, the adequacy of the overall reaction model for premixed, laminar, one-dimensional, steady-state flames was examined. The single-reaction model gave quite accurate results for burning velocity. The temperature and heat-release profiles were also generally accurate. The accuracy of the major-species profiles varied from fair to good. However, the optimal overall kinetic parameters varied with the equivalence ratio. In this report, the adequacy of an overall reaction model for premixed, laminar, one-dimensional, steady-state flames is examined for variations in initial temperature and pressure. The single reaction model gives quite accurate results for burning velocity; temperature and heat-release profiles are also generally accurate; major-species profiles are reproduced with fair to good accuracy. The optimal overall parameters change with initial temperature and pressure. However, a single set of parameters are found to be accurate over a limited range of initial temperatures and pressures.

  1. Adaptation of Extremophilic Proteins with Temperature and Pressure: Evidence from Initiation Factor 6.

    PubMed

    Calligari, Paolo A; Calandrini, Vania; Ollivier, Jacques; Artero, Jean-Baptiste; Härtlein, Michael; Johnson, Mark; Kneller, Gerald R

    2015-06-25

    In this work, we study dynamical properties of an extremophilic protein, Initiation Factor 6 (IF6), produced by the archeabacterium Methanocaldococcus jannascii, which thrives close to deep-sea hydrothermal vents where temperatures reach 80 °C and the pressure is up to 750 bar. Molecular dynamics simulations (MD) and quasi-elastic neutron scattering (QENS) measurements give new insights into the dynamical properties of this protein with respect to its eukaryotic and mesophilic homologue. Results obtained by MD are supported by QENS data and are interpreted within the framework of a fractional Brownian dynamics model for the characterization of protein relaxation dynamics. IF6 from M. jannaschii at high temperature and pressure shares similar flexibility with its eukaryotic homologue from S. cerevisieae under ambient conditions. This work shows for the first time, to our knowledge, that the very common pattern of corresponding states for thermophilic protein adaptation can be extended to thermo-barophilic proteins. A detailed analysis of dynamic properties and of local structural fluctuations reveals a complex pattern for "corresponding" structural flexibilities. In particular, in the case of IF6, the latter seems to be strongly related to the entropic contribution given by an additional, C-terminal, 20 amino-acid tail which is evolutionary conserved in all mesophilic IF6s. PMID:25996652

  2. Void formation during early stages of passivation: Initial oxidation of iron nanoparticles at room temperature

    NASA Astrophysics Data System (ADS)

    Wang, C. M.; Baer, D. R.; Thomas, L. E.; Amonette, J. E.; Antony, Jiji; Qiang, You; Duscher, G.

    2005-11-01

    The examination of nanoparticles allows study of some processes and mechanisms that are not as easily observed for films or other types of studies in which sample preparation artifacts have been the cause of some uncertainties. Microstructure of iron nanoparticles passivated with iron oxide shell was studied using high-resolution transmission electron microscopy and high-angle annular dark-field imaging in aberration-corrected scanning transmission electron microscopy. Voids were readily observed on both small single-crystal α-Fe nanoparticles formed in a sputtering process and the more complex particles created by reduction of an oxide by hydrogen. Although the formation of hollow spheres of nanoparticles has been engineered for Co at higher temperatures [Y. Yin, R. M. Riou, C. K. Erdonmez, S. Hughes, G. A. Somorjari, and A. P. Alivisatos, Science 304, 711 (2004)], they occur for iron at room temperature and provide insight into the initial oxidation processes of iron. There exists a critical size of ~8 nm for which the iron has been fully oxidized, leading to a hollow iron-oxide nanoparticle. For particles larger than the critical size, an iron/iron-oxide core-shell structure was formed and voids reside at the interface between the oxide shell and the iron core. The present observation provides new insight for tailoring of metal/metal-oxide core-shell structured nanoparticles for applications related to optics, magnetism, and nanoelectronics.

  3. Homogenisation algorithm skill testing with synthetic global benchmarks for the International Surface Temperature Initiative

    NASA Astrophysics Data System (ADS)

    Willet, Katherine; Venema, Victor; Williams, Claude; Aguilar, Enric; joliffe, Ian; Alexander, Lisa; Vincent, Lucie; Lund, Robert; Menne, Matt; Thorne, Peter; Auchmann, Renate; Warren, Rachel; Bronniman, Stefan; Thorarinsdotir, Thordis; Easterbrook, Steve; Gallagher, Colin; Lopardo, Giuseppina; Hausfather, Zeke; Berry, David

    2015-04-01

    Our surface temperature data are good enough to give us confidence that the world has warmed since 1880. However, they are not perfect - we cannot be precise in the amount of warming for the globe and especially for small regions or specific locations. Inhomogeneity (non-climate changes to the station record) is a major problem. While progress in detection of, and adjustment for inhomogeneities is continually advancing, monitoring effectiveness on large networks and gauging respective improvements in climate data quality is non-trivial. There is currently no internationally recognised means of robustly assessing the effectiveness of homogenisation methods on real data - and thus, the inhomogeneity uncertainty in those data. Here I present the work of the International Surface Temperature Initiative (ISTI; www.surfacetemperatures.org) Benchmarking working group. The aim is to quantify homogenisation algorithm skill on the global scale against realistic benchmarks. This involves the creation of synthetic worlds of surface temperature data, deliberate contamination of these with known errors and then assessment of the ability of homogenisation algorithms to detect and remove these errors. The ultimate aim is threefold: quantifying uncertainties in surface temperature data; enabling more meaningful product intercomparison; and improving homogenisation methods. There are five components work: 1. Create 30000 synthetic benchmark stations that look and feel like the real global temperature network, but do not contain any inhomogeneities: analog clean-worlds. 2. Design a set of error models which mimic the main types of inhomogeneities found in practice, and combined them with the analog clean-worlds to give analog error-worlds. 3. Engage with dataset creators to run their homogenisation algorithms blind on the analog error-world stations as they have done with the real data. 4. Design an assessment framework to gauge the degree to which analog error-worlds are returned to

  4. Copper-triazole interaction and coolant inhibitor depletion

    SciTech Connect

    Bartley, L.S.; Fritz, P.O.; Pellet, R.J.; Taylor, S.A.; Van de Ven, P.

    1999-08-01

    To a large extent, the depletion of tolyltriazole (TTZ) observed in several field tests may be attributed to the formation of a protective copper-triazole layer. Laboratory aging studies, shown to correlate with field experience, reveal that copper-TTZ layer formation depletes coolant TTZ levels in a fashion analogous to changes observed in the field. XPS and TPD-MS characterization of the complex formed indicates a strong chemical bond between copper and the adsorbed TTZ which can be desorbed thermally only at elevated temperatures. Electrochemical polarization experiments indicate that the layer provides good copper protection even when TTZ is absent from the coolant phase. Examination of copper cooling system components obtained after extensive field use reveals the presence of a similar protective layer.

  5. About the Influence of the initial Atmosphere on the Earth's Temperature Distribution during it's Accumulation

    NASA Astrophysics Data System (ADS)

    Khachay, Y.; Anfilogov, V.; Antipin, A.

    2012-04-01

    We suggested a new model for accumulation of planets of the Earth's group [1], which is based on the contemporary results of geochemical analyses, which allow to obtain the concentrations of short living radioactive isotopes of 26Al in the matter of the pre planet cloud [2]. With use of that data new estimations of temperature distribution into the growing planetary pre planetary bodies into the Earth's nebular zone had been obtained. For the further Earth's temperature evolution, as it had been showed by the results of numerical modeling, the main role belongs to the temperature distribution in the forming Earth's core and the existence of a dense and transparent atmosphere. The shadow influence of the initial atmosphere had been researched in the paper [3]. We shall give the main consideration to these problems in that paper. It had been shown in [1], that on the earliest accumulation stage the heat release by the decay of 26Al it is sufficient for forming a central melted area and solid relatively thin mainly silicate upper envelope in the pre planetary body, with dimensions, larger than (50-100) km. The impact velocities on that stage are yet not large, therefore by the bodies impact with these or near dimensions liquid and mainly iron their parts merge, but the masses of the pre planetary bodies are not sufficient to gravitational keeping of silicate parts of the cold solid envelope. On that stage they remain into the nebular zone of the proto planet and the mechanism of matter differentiation for the future core and mantle reservoirs realizes. The process takes place yet in small bodies and is in time to finish during less than 10 million years. The next forming of the core and mantle structure continues according to all known estimations about 100 million years. Because of the merging of inner liquid parts of impacting bodies occur due to inelastic impact, the main part of potential energy transforms into heat. That continues up to that time when the iron

  6. Temperature dependence of habituation of the initial responses to cold-water immersion.

    PubMed

    Tipton, M J; Golden, F S; Higenbottam, C; Mekjavic, I B; Eglin, C M

    1998-08-01

    The initial responses to cold-water immersion, evoked by stimulation of peripheral cold receptors, include tachycardia, a reflex inspiratory gasp and uncontrollable hyperventilation. When immersed naked, the maximum responses are initiated in water at 10 degrees C, with smaller responses being observed following immersion in water at 15 degrees C. Habituation of the initial responses can be achieved following repeated immersions, but the specificity of this response with regard to water temperature is not known. Thirteen healthy male volunteers were divided into a control (C) group (n = 5) and a habituation (H) group (n = 8). Each subject undertook two 3-min head-out immersions in water at 10 degrees C wearing swimming trunks. These immersions took place at a corresponding time of day with 4 days separating the two immersions. In the intervening period the C group were not exposed to cold water, while the H group undertook another six, 3-min, head-out immersions in water at 15 degrees C. Respiratory rate (fR), inspiratory minute volume (VI) and heart rate (fH) were measured continuously throughout each immersion. Following repeated immersions in water at 15 degrees C, the fR, VI and fH responses of the H group over the first 30 s of immersion were reduced (P < 0.01) from 33.3 breaths x min(-1), 50.5 l x min(-1) and 114 beats x min(-1) respectively, to 19.8 breaths x min(-1) 26.41 x min(-1) and 98 beats x min(-1), respectively. In water at 10 degrees C these responses were reduced (P < 0.01) from 47.3 breaths x min(-1), 67.61 x min(-1) and 128 beats x min(-1) to 24.0 breaths x min(-1), 29.5 l x min(-1) and 109 beats x min(-1), respectively over a corresponding period of immersion. Similar reductions were observed during the last 2.5 min of immersions. The initial responses of the C group were unchanged. It is concluded that habituation of the cold shock response can be achieved by immersion in warmer water than that for which protection is required. This suggests

  7. Coolant passage heat transfer with rotation

    NASA Astrophysics Data System (ADS)

    Hajek, T. J.; Higgins, A. W.

    1985-10-01

    The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques, and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

  8. Mixed convective/dynamic roll vortices and their effects on initial wind and temperature profiles

    NASA Technical Reports Server (NTRS)

    Haack, Tracy; Shirer, Hampton N.

    1991-01-01

    The onset and development of both dynamically and convectively forced boundary layer rolls are studied with linear and nonlinear analyses of a truncated spectral model of shallow Boussinesq flow. Emphasis is given here on the energetics of the dominant roll modes, on the magnitudes of the roll-induced modifications of the initial basic state wind and temperature profiles, and on the sensitivity of the linear stability results to the use of modified profiles as basic states. It is demonstrated that the roll circulations can produce substantial changes to the cross-roll component of the initial wind profile and that significant changes in orientation angle estimates can result from use of a roll-modified profile in the stability analysis. These results demonstrate that roll contributions must be removed from observed background wind profiles before using them to investigate the mechanisms underlying actual secondary flows in the boundary layer. The model is developed quite generally to accept arbitrary basic state wind profiles as dynamic forcing. An Ekman profile is chosen here merely to provide a means for easy comparison with other theoretical boundary layer studies; the ultimate application of the model is to study observed boundary layer profiles. Results of the analytic stability analysis are validated by comparing them with results from a larger linear model. For an appropriate Ekman depth, a complete set of transition curves is given in forcing parameter space for roll modes driven both thermally and dynamically. Preferred orientation angles, horizontal wavelengths and propagation frequencies, as well as energetics and wind profile modifications, are all shown to agree rather well with results from studies on Ekman layers as well as with studies on near-neutral and convective atmospheric boundary layers.

  9. Initial Water Content and Temperature Effects on Electrokinetic Removal of Aluminium in Drinking Water Sludge

    NASA Astrophysics Data System (ADS)

    Cherifi, M.; Hazourli, S.; Ziati, M.

    2009-11-01

    Electrokinetics is a developping technology that is intended to separate and extract heavy metals, radionuclides, and organic contaminants from saturated or unsaturated soils, sludges and sediments, and groundwater. The goal of electrokinetic remediation is to effect the migration of subsurface contaminants in an imposed electric field. This technique is known as electrokinetic remediation, electroreclamation, electrochemical decontamination, electrorestoration, electromigration or electrochemical soil processing. Electrokinetics involves the installation of electrodes into the subsurface surrounding the contaminated region. After the electrodes are in place, a low electrical potential is applied across the anode(s) (positively charged electrode) and the cathode(s) (negatively charged electrode). As a result of the electrical gradient, different physico-chemical reactions occur and contaminant transport occurs due to various mechanisms within the soil and groundwater. Generally, for the migration to be significant, the contaminants should be in a soluble form. If they are not soluble, they need to be desorbed, dissolved, and/or solubilized into the pore solution before they can be adequately transported from the soil to an electrode wells/reservoirs. Different types of contaminants have been investigated and research has been conducted to optimize the electrokinetic variables. The present study was undertaken to systematically investigate the effect of initial sludge water content, and heating on the electrokinetic remediation of alumium-contaminated sludge. A total of four laboratory experiments were conducted using drinking water sludge. The first two tests studied the effect of variation of initial sludge water content under an ambient temperature, and the last two tests studied the effect of heating on electrokinetic remediation under conditions of both constant saturation and applied voltage.

  10. Flame Speeds of Methane-Air, Propane-Air, and Ethylene-Air Mixtures at Low Initial Temperatures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L; Heimel, Sheldon

    1952-01-01

    Flame speeds were determined for methane-air, propane-air, and ethylene-air mixtures at -73 C and for methane-air mixtures at -132 C. The data extend the curves of maximum flame speed against initial mixture temperature previously established for the range from room temperature to 344 C. Empirical equations for maximum flame speed u(cm/ sec) as a function of initial mixture temperature T(sub O) were determined to be as follows: for methane, for T(sub O) from 141 to 615 K, u = 8 + 0.000160 T(sub O)(exp 2.11); for propane, for T(sub O) from 200 to 616 K, u = 10 + 0.000342 T(sub O)(exp 2.00); for ethylene, for T(sub O) from 200 to 617 K, u = 10 + 0.00259 T(sub O)(exp 1.74). Relative flame speeds at low initial temperatures were predicted within approximately 20 percent by either the thermal theory as presented by Semenov or by the diffusion theory of Tanford and Pease. The same order was found previously for high initial temperatures. The low-temperature data were also found to extend the linear correlations between maximum flame speed and calculated equilibrium active-radical concentrations, which were established by the previously reported high-temperature data.

  11. Dynamic Fracture Initiation Toughness at Elevated Temperatures With Application to the New Generation of Titanium Aluminide Alloys. Chapter 8

    NASA Technical Reports Server (NTRS)

    Shazly, Mostafa; Prakash, Vikas; Draper, Susan; Shukla, Arun (Editor)

    2006-01-01

    Recently, a new generation of titanium aluminide alloy, named Gamma-Met PX, has been developed with better rolling and post-rolling characteristics. I'revious work on this alloy has shown the material to have higher strengths at room and elevated temperatures when compared with other gamma titanium aluminides. In particular, this new alloy has shown increased ductility at elevated temperatures under both quasi-static and high strain rate uniaxial compressive loading. However, its high strain rate tensile ductility at room and elevated temperatures is limited to approx. 1%. In the present chapter, results of a study to investigate the effects of loading rate and test temperature on the dynamic fracture initiation toughness in Gamma-Met PX are presented. Modified split Hopkinson pressure bar was used along with high-speed photography to determine the crack initiation time. Three-point bend dynamic fracture experiments were conducted at impact speeds of approx. 1 m/s and tests temperatures of up-to 1200 C. The results show that thc dynamic fracture initiation toughness decreases with increasing test temperatures beyond 600 C. Furthermore, thc effect of long time high temperature air exposure on the fracture toughness was investigated. The dynamic fracture initiation toughness was found to decrease with increasing exposure time. The reasons behind this drop are analyzed and discussed.

  12. Computer code for predicting coolant flow and heat transfer in turbomachinery

    NASA Technical Reports Server (NTRS)

    Meitner, Peter L.

    1990-01-01

    A computer code was developed to analyze any turbomachinery coolant flow path geometry that consist of a single flow passage with a unique inlet and exit. Flow can be bled off for tip-cap impingement cooling, and a flow bypass can be specified in which coolant flow is taken off at one point in the flow channel and reintroduced at a point farther downstream in the same channel. The user may either choose the coolant flow rate or let the program determine the flow rate from specified inlet and exit conditions. The computer code integrates the 1-D momentum and energy equations along a defined flow path and calculates the coolant's flow rate, temperature, pressure, and velocity and the heat transfer coefficients along the passage. The equations account for area change, mass addition or subtraction, pumping, friction, and heat transfer.

  13. A Case Study Of Applying Infrared Thermography To Identify A Coolant Leak In A Municipal Ice Skating Rink

    NASA Astrophysics Data System (ADS)

    Wallace, Jay R.

    1989-03-01

    This paper deals with the application of infrared imaging radiometry as a diagnostic inspection tool for locating a concealed leak in the refrigeration system supplying glycol coolant to the arena floor of an ice skating rink in a municipal coliseum facility. Scanning approximately 10 miles of black iron tubing embedded in the arena floor resulted in locating a leak within the supply/return side of the system. A secondary disclosure was a restriction to normal coolant flow in some delivery loops caused by sludge build-up. Specific inspection procedures were established to enhance temperature differentials suitable for good thermal imaging. One procedure utilized the temperature and pressure of the city water supply; a second the availability of 130F hot water from the facility's boiler system; and a third the building's own internal ambient temperature. Destructive testing and other data collection equipment confirmed the thermographic findings revealing a section of corrosion damaged pipe. Repair and flushing of the system was quickly completed with a minimum of construction costs and inconvenience. No financial losses were incurred due to the interruption of scheduled revenue events. Probable cause for the shutdown condition was attributed to a flawed installation decision made 15 years earlier during the initial construction stage.

  14. Composition of incipient passivating layers on heat-rejecting aluminum in carboxylate- and silicate-inhibited coolants: Correlation with ASTM D 4340 weight losses

    SciTech Connect

    Wagner, F.T.; Moylan, T.E.; Simko, S.J.; Militello, M.C.

    1999-08-01

    X-ray photoelectron spectroscopy identified compositional differences between passivating layers initially formed in carboxylated coolants, in silicated coolants, and in a mixture thereof on well-controlled 319 aluminum surfaces under heat-rejecting conditions. The layer formed in silicated coolant was primarily silica, while that in carboxylated coolant was primarily hydrated alumina. Competition between inhibitor packages when carboxylated coolant was contaminated from the start with low levels of silicated coolant produced films which were not simply patchwise mixtures of the pure-coolant film types. The surface analytical results aid the interpretation of subtle differences in weight losses under the ASTM Standard Test Method for Corrosion of Cast Aluminum Alloys in Engine Coolants Under Heat-Rejecting Conditions (D 4340) in carboxylated versus silicated coolants that became more pronounced when testing was carried out at a vehicle-like 50% coolant concentration. Results from time-resolved D4340 measurements and from a two-step cleaning procedure further contribute towards proper evaluation of D4340 weight losses in the different coolant types.

  15. Nuclear reactor loss of coolant protection system

    SciTech Connect

    Loose, R.A.

    1986-03-18

    A pressurized water reactor system is described of a nuclear power plant having a water storage tank for providing emergency coolant water and means provided external to the containment vessel, for use in the event of a primary loss of coolant situation, to circulate emergency water as a coolant by withdrawal through a wall of the containment vessel and return the same back through the wall of the containment vessel and passing the water through a heat exchange means prior to use as a coolant for the reactor core. The improvement described here consists of: an enslosure, the interior of which is sealed to the atmosphere, positioned adjacent to and exterior of a wall of the containment vessel; an inlet conduit, enclosed within a sealed outer casing, communicating between the interior of the containment vessel and the interior of the enclosure; an exhaust conduit, enclosed within a sealed outer casing, communicating between the interior of the enclosure and the interior of the containment vessel; a rupture disc on the inlet conduit within the enclosure, such that failure of the exhaust conduit within the enclosure will produce an increase of the pressure within the enclosure and above a predetermined pressure will fracture the rupture disc, and will circulate the coolant within the enclosure; and means within the interior of the enclosure for pumping coolant from the interior of the containment vessel through the inlet conduit, and back to the interior of the containment vessel through the exhaust conduit; whereby if either of the conduits should fail, coolant will be collected within the enclosure and sealed to the atmosphere.

  16. Viscosity of alumina nanoparticles dispersed in car engine coolant

    SciTech Connect

    Kole, Madhusree; Dey, T.K.

    2010-09-15

    The present paper, describes our experimental results on the viscosity of the nanofluid prepared by dispersing alumina nanoparticles (<50 nm) in commercial car coolant. The nanofluid prepared with calculated amount of oleic acid (surfactant) was tested to be stable for more than 80 days. The viscosity of the nanofluids is measured both as a function of alumina volume fraction and temperature between 10 and 50 C. While the pure base fluid display Newtonian behavior over the measured temperature, it transforms to a non-Newtonian fluid with addition of a small amount of alumina nanoparticles. Our results show that viscosity of the nanofluid increases with increasing nanoparticle concentration and decreases with increase in temperature. Most of the frequently used classical models severely under predict the measured viscosity. Volume fraction dependence of the nanofluid viscosity, however, is predicted fairly well on the basis of a recently reported theoretical model for nanofluids that takes into account the effect of Brownian motion of nanoparticles in the nanofluid. The temperature dependence of the viscosity of engine coolant based alumina nanofluids obeys the empirical correlation of the type: log ({mu}{sub nf}) = A exp(BT), proposed earlier by Namburu et al. (author)

  17. Time-temperature analysis of damage initiation and growth in composite laminates

    SciTech Connect

    Negesh, S.

    1992-01-01

    Polymer-based composites are used in aerospace structures due to their high strength to weight ratio. However polymers also exhibit time-dependent behavior and this behavior may in turn be affected by high temperature and humid environments. Long-term effects manifest themselves in the form of loss of stiffness and/or strength. And, in this regard, the contributing factors could stem from the time-dependent material behavior as well as the accumulation of damages in time. Clearly, generic methodology is needed which addresses the fundamental issues caused by both of the contributing factors. The objective of the present study is to investigate the time-dependent damage initiation and growth behavior associated with the various sublaminate damage modes in polymer-based composites. A quasi-three dimensional finite element procedure is first developed based on the linear theory of viscoelasticity for simulating sublaminate damages in composite laminates. Specifically the unidirectional plies of the laminate are represented by a set of linear anisotropic, viscoelastic constitutive relations. Damage modes in the forms of transverse cracks, delamination of fiber-wise splitting are incorporated in the analysis by means of appropriately evolving local boundary conditions. Calculation of the stress fields and fracture parameters such as the strain energy release rates (G) and the stress intensity factors (K) associated with the different modes of damage and a different stages of evolution are also made a part of the routine. Numerical solutions are obtained by a convolution as well as a quasi-elastic technique. To illustrate the applicability of the numerical routine, the problem of fiber-wise splitting is chosen. Since fiber-wise splitting is a mixed-mode type of failure, an appropriate mixed-mode fracture criterion is needed for predicting its onset and growth.

  18. Molecular Design for Cryogenic Magnetic Coolants.

    PubMed

    Liu, Jun-Liang; Chen, Yan-Cong; Tong, Ming-Liang

    2016-04-01

    The area of molecular magnetic coolants has developed rapidly in recent years. A large number of competitive candidates have been reported, with the cooling performances chasing each other. In this account, four explicit strategies, namely, increasing ground-state spin, reducing magnetic anisotropy, weakening magnetic interactions, and lowering the molecular weight, are proposed from the theoretical viewpoint towards improving the magnetocaloric effect (MCE). According to this guidance, these successful strategies are discussed to pursue excellent magnetic coolants. This is accompanied by a discussion of the representative examples reported by our group. The magnetic entropy change increases from one compound to another, which in the most pronounced cases is suggestive of being the largest MCE in magnetic coolants. PMID:26929130

  19. Evidence for cumulative temperature as an initiating and terminating factor in downstream migratory behavior of Atlantic salmon (Salmo salar) smolts

    USGS Publications Warehouse

    Zydlewski, G.B.; Haro, A.; McCormick, S.D.

    2005-01-01

    Temperature control of Atlantic salmon (Salmo salar) smolt migration was tested using a novel technique allowing nearly continuous monitoring of behavior with complete control over environmental conditions. Parr and presmolts were implanted with passive integrated transponder tags, placed in simulated streams, and monitored for upstream and downstream movements. Beginning 18 April, temperature was increased 1??C every third day (advanced), fourth day (ambient), and tenth day (delayed). Smolt downstream movements were initially low, peaked in mid-May, and subsequently declined under all conditions. Parr downstream movements were significantly lower than those of smolts in all treatments (0.8 ?? 0.5 movement??day-1 versus 26.5 ?? 4.5 movements??day-1, mean ?? SE) and showed no increase. At delayed temperatures, smolts sustained downstream movements through July; those under ambient and advanced conditions ceased activity by mid-June. Initiation and termination of downstream movements occurred at significantly different temperatures but at the same number of degree-days in all treatments. Physiological changes associated with smolting (gill Na+,K +-ATPase activity and plasma thyroxine) were coincident with behavioral changes. This is the first evidence of a behavioral component to the smolt window. We found that temperature experience over time is more relevant to initiation and termination of downstream movement than a temperature threshold. ?? 2005 NRC Canada.

  20. Vegetable oils: liquid coolants for solar heating and cooling applications

    SciTech Connect

    Ingley, H A

    1980-02-01

    It has been proposed that vegetable oils, renewable byproducts of agriculture processes, be investigated for possible use as liquid coolants. The major thrust of the project was to investigate several thermophysical properties of the four vegetable oils selected. Vapor pressures, specific heat, viscosity, density, and thermal conductivity were determined over a range of temperatures for corn, soybean, peanut, and cottonseed oil. ASTM standard methods were used for these determinations. In addition, chemical analyses were performed on samples of each oil. The samples were collected before and after each experiment so that any changes in composition could be noted. The tests included iodine number, fatty acid, and moisture content determination. (MHR)

  1. TACT1- TRANSIENT THERMAL ANALYSIS OF A COOLED TURBINE BLADE OR VANE EQUIPPED WITH A COOLANT INSERT

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1994-01-01

    As turbine-engine core operating conditions become more severe, designers must develop more effective means of cooling blades and vanes. In order to design reliable, cooled turbine blades, advanced transient thermal calculation techniques are required. The TACT1 computer program was developed to perform transient and steady-state heat-transfer and coolant-flow analyses for cooled blades, given the outside hot-gas boundary condition, the coolant inlet conditions, the geometry of the blade shell, and the cooling configuration. TACT1 can analyze turbine blades, or vanes, equipped with a central coolant-plenum insert from which coolant-air impinges on the inner surface of the blade shell. Coolant-side heat-transfer coefficients are calculated with the heat transfer mode at each station being user specified as either impingement with crossflow, forced convection channel flow, or forced convection over pin fins. A limited capability to handle film cooling is also available in the program. The TACT1 program solves for the blade temperature distribution using a transient energy equation for each node. The nodal energy balances are linearized, one-dimensional, heat-conduction equations which are applied at the wall-outer-surface node, at the junction of the cladding and the metal node, and at the wall-inner-surface node. At the mid-metal node a linear, three-dimensional, heat-conduction equation is used. Similarly, the coolant pressure distribution is determined by solving the set of transfer momentum equations for the one-dimensional flow between adjacent fluid nodes. In the coolant channel, energy and momentum equations for one-dimensional compressible flow, including friction and heat transfer, are used for the elemental channel length between two coolant nodes. The TACT1 program first obtains a steady-state solution using iterative calculations to obtain convergence of stable temperatures, pressures, coolant-flow split, and overall coolant mass balance. Transient

  2. Reduction of the Livestock Ammonia Emission under the Changing Temperature during the Initial Manure Nitrogen Biomineralization

    PubMed Central

    Bagdonienė, Indrė; Baležentienė, Ligita

    2013-01-01

    Experimental data were applied for the modelling optimal cowshed temperature environment in laboratory test bench by a mass-flow method. The principal factor affecting exponent growth of ammonia emission was increasing air and manure surface temperature. With the manure temperature increasing from 4°C to 30°C, growth in the ammonia emission grew fourfold, that is, from 102 to 430 mg m−2h−1. Especial risk emerges when temperature exceeds 20°C: an increase in temperature of 1°C contributes to the intensity of ammonia emission by 17 mg m−2h−1. The temperatures of air and manure surface as well as those of its layers are important when analysing emission processes from manure. Indeed, it affects the processes occurring on the manure surface, namely, dehydration and crust formation. To reduce ammonia emission from cowshed, it is important to optimize the inner temperature control and to manage air circulation, especially at higher temperatures, preventing the warm ambient air from blowing direct to manure. Decrease in mean annual temperature of 1°C would reduce the annual ammonia emission by some 5.0%. The air temperature range varied between −15°C and 30°C in barns. The highest mean annual temperature (14.6°C) and ammonia emission (218 mg m−2h−1) were observed in the semideep cowshed. PMID:24453912

  3. On-Line Coolant Chemistry Analysis

    SciTech Connect

    LM Bachman

    2006-07-19

    Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.

  4. Coolant monitoring apparatus for nuclear reactors

    DOEpatents

    Tokarz, Richard D.

    1983-01-01

    A system for monitoring coolant conditions within a pressurized vessel. A length of tubing extends outward from the vessel from an open end containing a first line restriction at the location to be monitored. The flowing fluid is cooled and condensed before passing through a second line restriction. Measurement of pressure drop at the second line restriction gives an indication of fluid condition at the first line restriction. Multiple lengths of tubing with open ends at incremental elevations can measure coolant level within the vessel.

  5. Emergency cooling analysis for the loss of coolant malfunction

    NASA Technical Reports Server (NTRS)

    Peoples, J. A.

    1972-01-01

    This report examines the dynamic response of a conceptual space power fast-spectrum lithium cooled reactor to the loss of coolant malfunction and several emergency cooling concepts. The results show that, following the loss of primary coolant, the peak temperatures of the center most 73 fuel elements can range from 2556 K to the region of the fuel melting point of 3122 K within 3600 seconds after the start of the accident. Two types of emergency aftercooling concepts were examined: (1) full core open loop cooling and (2) partial core closed loop cooling. The full core open loop concept is a one pass method of supplying lithium to the 247 fuel pins. This method can maintain fuel temperature below the 1611 K transient damage limit but requires a sizable 22,680-kilogram auxiliary lithium supply. The second concept utilizes a redundant internal closed loop to supply lithium to only the central area of each hexagonal fuel array. By using this method and supplying lithium to only the triflute region, fuel temperatures can be held well below the transient damage limit.

  6. Alternative Approaches to Land Initialization for Seasonal Precipitation and Temperature Forecasts

    NASA Technical Reports Server (NTRS)

    Koster, Randal; Suarez, Max; Liu, Ping; Jambor, Urszula

    2004-01-01

    The seasonal prediction system of the NASA Global Modeling and Assimilation Office is used to generate ensembles of summer forecasts utilizing realistic soil moisture initialization. To derive the realistic land states, we drive offline the system's land model with realistic meteorological forcing over the period 1979-1993 (in cooperation with the Global Land Data Assimilation System project at GSFC) and then extract the state variables' values on the chosen forecast start dates. A parallel series of forecast ensembles is performed with a random (though climatologically consistent) set of land initial conditions; by comparing the two sets of ensembles, we can isolate the impact of land initialization on forecast skill from that of the imposed SSTs. The base initialization experiment is supplemented with several forecast ensembles that use alternative initialization techniques. One ensemble addresses the impact of minimizing climate drift in the system through the scaling of the initial conditions, and another is designed to isolate the importance of the precipitation signal from that of all other signals in the antecedent offline forcing. A third ensemble includes a more realistic initialization of the atmosphere along with the land initialization. The impact of each variation on forecast skill is quantified.

  7. Initial and apparent temperatures of finite nuclear systems - a quantum statistical thermodynamics study.

    NASA Astrophysics Data System (ADS)

    Majka; Staszel, P.; Natowitz, J. B.; Cibor, J.; Hagel, K.; Li, J.; Mdeiwayeh, N.; Wada, R.; Zhao, Y.

    1996-10-01

    Quantum statistical thermodynamics has been used to calculate the number of available states and their occupation for fermions and bosons at temperature, T_in, of finite nuclear sytems. An apparent temperature of these systems, T_app, has been calculated from double yield ratios of two isotope pairs. The importance of employing the quantum statistics when high densities and/or low temperatures are involved is shown. However, at high temperatures and low densities, the system behaves as a Maxwell-Boltzmann gas. Sequental decays of fragments from excited states influence the double yield ratio observable, causing problems with the temperature extraction. The model has been applied to study the high temperature branch of the "caloric curve".

  8. Axi-symmetric generalized thermoelastic diffusion problem with two-temperature and initial stress under fractional order heat conduction

    NASA Astrophysics Data System (ADS)

    Deswal, Sunita; Kalkal, Kapil Kumar; Sheoran, Sandeep Singh

    2016-09-01

    A mathematical model of fractional order two-temperature generalized thermoelasticity with diffusion and initial stress is proposed to analyze the transient wave phenomenon in an infinite thermoelastic half-space. The governing equations are derived in cylindrical coordinates for a two dimensional axi-symmetric problem. The analytical solution is procured by employing the Laplace and Hankel transforms for time and space variables respectively. The solutions are investigated in detail for a time dependent heat source. By using numerical inversion method of integral transforms, we obtain the solutions for displacement, stress, temperature and diffusion fields in physical domain. Computations are carried out for copper material and displayed graphically. The effect of fractional order parameter, two-temperature parameter, diffusion, initial stress and time on the different thermoelastic and diffusion fields is analyzed on the basis of analytical and numerical results. Some special cases have also been deduced from the present investigation.

  9. Naphthalene degradation in seawater by UV irradiation: the effects of fluence rate, salinity, temperature and initial concentration.

    PubMed

    Jing, Liang; Chen, Bing; Zhang, Baiyu; Zheng, Jisi; Liu, Bo

    2014-04-15

    A large amount of oil pollution at sea is produced by the operational discharge of oily wastewater. The removal of polycyclic aromatic hydrocarbons (PAHs) from such sources using UV irradiation has become attractive, yet the photolysis mechanism in seawater has remained unclear. This study examines the photodegradation kinetics of naphthalene in natural seawater through a full factorial design of experiments (DOE). The effects of fluence rate, salinity, temperature and initial concentration are investigated. Results show that fluence rate, temperature and the interaction between temperature and initial concentration are the most influential factors. An increase in fluence rate can linearly promote the photodegradation process. Salinity increasingly impedes the removal of naphthalene because of the existence of free-radical scavengers and photon competitors. The results will help understand the photolysis mechanism of PAHs and develop more effective methods for treating oily seawater generated from offshore industries. PMID:24576392

  10. The development of theoretical relationships between some handling parameters (setting time and setting temperature), composition (relative amounts of initiator and activator) and ambient temperature for acrylic bone cement.

    PubMed

    Milner, Richard

    2004-02-15

    Commercially available acrylic bone cements are two-component systems based on the polymerization of methyl methacrylate around poly(methyl methacrylate) particles. When benzoyl peroxide (BPO), which is the initiator, in the powder component meets accelerator (N,N-dimethyl-p-toluidine (DMpT)) in the liquid component, radicals are produced, initiating the polymerization. This solidifies the cement. In this work, kinetic expressions have been developed that describe the relationship between bone cement setting time on the one hand, and BPO and DMpT concentrations on the other. Changes in setting time with ambient temperature follow a complex relationship, because both the polymerization process (initiation, propagation, and termination) and the swelling and dissolution of the polymer particles contribute to setting. The contribution of polymer swelling and dissolution to the setting process was determined by developing a relationship between the doughing time, which is substantially independent of DMpT or BPO concentrations, and ambient temperature. A value of 64 kJ mol(-1) was found for the activation energy for this process. An activation energy for the overall setting process of 68 kJ mol(-1) was determined from setting-time measurements over several ambient temperatures. This indicates that the sensitivity of setting time to temperature depends more on swelling and dissolution than on the polymerization process. PMID:14737766

  11. NGNP Reactor Coolant Chemistry Control Study

    SciTech Connect

    Brian Castle

    2010-11-01

    The main focus of this paper is to identify the most desirable ranges of impurity levels in the primary coolant to optimize component life in the primary circuit of the Next Generation Nuclear Plant (NGNP), which will either be a prismatic block or pebble bed reactor.

  12. Rapid electrochemical screening of engine coolants. Correlation of electrochemical potentiometric measurements with ASTM D 1384 glassware corrosion test

    SciTech Connect

    Doucet, G.P.; Jackson, J.M.; Kriegel, O.A.; Passwater, D.K.; Prieto, N.E.

    1999-08-01

    Engine coolants are typically subjected to comprehensive performance evaluations that involve multiple laboratory and field tests. These tests can take several weeks to conduct and can be expensive. The tests can involve everything from preliminary chemical screening to long term fleet tests. An important test conducted at the beginning of coolant formula development to screen the corrosion performance of engine coolants is described in ASTM D 1384. If the coolant formula passes the test, it is then subjected to more rigorous testing. Conducting the test described in ASTM D 1384 takes two weeks, and determining the coolant corrosion performance under several test parameters can takes resources and time that users seldom have. Therefore, it is very desirable to have tests that can be used for rapid screening and quality assurance of coolants. The purpose of this study was to conduct electrochemical tests that can ultimately be used for quick initial screening of engine coolants. The specific intent of the electrochemical tests is to use ASTM D 1384 as a model and to attempt to duplicate its results. Implementation of the electrochemical tests could accelerate the process of selecting promising coolant formulas and reduce coolant evaluation time and cost. Various electrochemical tests were conducted to determine the corrosion performance of several engine coolant formulas. The test results were compared to those obtained from the ASTM D 1384 test. These tests were conducted on the same metal specimens and under similar conditions as those used in the ASTM D 1384 test. The electrochemical tests included the determination of open circuit potential (OCP) for the various metal specimens, anodic and cathodic polarization curves for the various metal specimens, corrosion rate for metal specimens involved in a galvanic triad, and critical pitting potential (CPP) for aluminum (pitting of aluminum engine components and cooling systems is a cause for concern). The details for

  13. Analysis of loss-of-coolant and loss-of-flow accidents in the first wall cooling system of NET/ITER

    NASA Astrophysics Data System (ADS)

    Komen, E. M. J.; Koning, H.

    1994-03-01

    This paper presents the thermal-hydraulic analysis of potential accidents in the first wall cooling system of the Next European Torus or the International Thermonuclear Experimental Reactor. Three ex-vessel loss-of-coolant accidents, two in-vessel loss-of-coolant accidents, and three loss-of-flow accidents have been analyzed using the thermal-hydraulic system analysis code RELAP5/MOD3. The analyses deal with the transient thermal-hydraulic behavior inside the cooling systems and the temperature development inside the nuclear components during these accidents. The analysis of the different accident scenarios has been performed without operation of emergency cooling systems. The results of the analyses indicate that a loss of forced coolant flow through the first wall rapidly causes dryout in the first wall cooling pipes. Following dryout, melting in the first wall starts within about 130 s in case of ongoing plasma burning. In case of large break LOCAs and ongoing plasma burning, melting in the first wall starts about 90 s after accident initiation.

  14. Use of a temperature-initiated passive cooling system (TIPACS) for the modular high-temperature gas-cooled reactor cavity cooling system (RCCS)

    SciTech Connect

    Forsberg, C.W.; Conklin, J.; Reich, W.J.

    1994-04-01

    A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS`s heat-removal capabilities. Section 5 analyzes the operation of the temperature-control mechanism that determines under what conditions the TIPACS rejects heat to the environment. Section 6 addresses other design and operational issues. Section 7 identifies uncertainties, and Section 8 provides conclusions. The appendixes provide the detailed data and models used in the analysis.

  15. Design criteria for Waste Coolant Processing Facility and preliminary proposal 722 for Waste Coolant Processing Facility

    SciTech Connect

    Not Available

    1991-09-27

    This document contains the design criteria to be used by the architect-engineer (A-E) in the performance of Titles 1 and 2 design for the construction of a facility to treat the biodegradable, water soluble, waste machine coolant generated at the Y-12 plant. The purpose of this facility is to reduce the organic loading of coolants prior to final treatment at the proposed West Tank Farm Treatment Facility.

  16. Surface Treatment to Improve Corrosion Resistance in Lead-Alloy Coolants

    SciTech Connect

    Todd R. Allen; Kumar Sridharan; McLean T. Machut; Lizhen Tan

    2007-08-29

    One of the six proposed advanced reactor designs of the Generation IV Initiative, the Leadcooled Fast Reactor (LFR) possesses many characteristics that make it a desirable candidate for future nuclear energy production and responsible actinide management. These characteristics include favorable heat transfer, fluid dynamics, and neutronic performance compared to other candidate coolants. However, the use of a heavy liquid metal coolant presents a challenge for reactor designers in regards to reliable structural and fuel cladding materials in both a highly corrosive high temperature liquid metal and an intense radiation fieldi. Flow corrosion studies at the University of Wisconsin have examined the corrosion performance of candidate materials for application in the LFR concept as well as the viability of various surface treatments to improve the materials’ compatibility. To date this research has included several focus areas, which include the formulation of an understanding of corrosion mechanisms and the examination of the effects of chemical and mechanical surface modifications on the materials’ performance in liquid lead-bismuth by experimental testing in Los Alamos National Laboratory’s DELTA Loop, as well as comparison of experimental findings to numerical and physical models for long term corrosion prediction. This report will first review the literature and introduce the experiments and data that will be used to benchmark theoretical calculations. The experimental results will be followed by a brief review of the underlying theory and methodology for the physical and theoretical models. Finally, the results of theoretical calculations as well as experimentally obtained benchmarks and comparisons to the literature are presented.

  17. Evaluation of secondary coolant control design alternatives and their effects on heat removal performance

    SciTech Connect

    Khayat, M.I.; Anderson, J.; Battle, R.; March-Leuba, J.

    1994-03-01

    This report documents a series of calculations that evaluate the performance of the core-inlet temperature controller under different transient conditions and design options. The present analyses show that the core-inlet temperature can be controlled at {approx}45{degrees}C under all transient conditions analyzed using the controller design described in the conceptual design report, which includes variable-speed secondary coolant pumps and variable-speed cooling tower fans. This study also shows that a constant-speed secondary pump would be sufficient to maintain core-inlet temperature <45{degrees}C if this temperature is allowed to drop below the set point during some demanding transients, such as normal startup. The use of secondary loop hot coolant to warm the reactor building was also evaluated; however, optimization of the secondary hot-leg temperature can only be achieved by trading off control of the primary side core-inlet temperature.

  18. Temperature-dependent remote control of polarization and coherence intensity with sender's pure initial state

    NASA Astrophysics Data System (ADS)

    Fel'dman, E. B.; Kuznetsova, E. I.; Zenchuk, A. I.

    2016-06-01

    We study the remote creation of the polarization and intensity of the first-order coherence (or coherence intensity) in long spin-1/2 chains with one-qubit sender and receiver. Therewith we use a physically motivated initial condition with the pure state of the sender and the thermodynamical equilibrium state of the other nodes. The main part of the creatable region is a one-to-one map of the initial state (control) parameters, except the small subregion twice covered by the control parameters, which appears owing to the chosen initial state. The polarization and coherence intensity behave differently in the state creation process. In particular, the coherence intensity cannot reach any significant value unless the polarization is large in long chains (unlike the short ones), but the opposite is not true. The coherence intensity vanishes with an increase in the chain length, while the polarization (by absolute value) is not sensitive to this parameter. We represent several characteristics of the creatable polarization and coherence intensity and describe their relation to the parameters of the initial state. The link to the eigenvalue-eigenvector parametrization of the receiver's state space is given.

  19. Temperature-dependent remote control of polarization and coherence intensity with sender's pure initial state

    NASA Astrophysics Data System (ADS)

    Fel'dman, E. B.; Kuznetsova, E. I.; Zenchuk, A. I.

    2016-03-01

    We study the remote creation of the polarization and intensity of the first-order coherence (or coherence intensity) in long spin-1/2 chains with one-qubit sender and receiver. Therewith we use a physically motivated initial condition with the pure state of the sender and the thermodynamical equilibrium state of the other nodes. The main part of the creatable region is a one-to-one map of the initial state (control) parameters, except the small subregion twice covered by the control parameters, which appears owing to the chosen initial state. The polarization and coherence intensity behave differently in the state creation process. In particular, the coherence intensity cannot reach any significant value unless the polarization is large in long chains (unlike the short ones), but the opposite is not true. The coherence intensity vanishes with an increase in the chain length, while the polarization (by absolute value) is not sensitive to this parameter. We represent several characteristics of the creatable polarization and coherence intensity and describe their relation to the parameters of the initial state. The link to the eigenvalue-eigenvector parametrization of the receiver's state space is given.

  20. Brief summary of the evolution of high-temperature creep-fatigue life prediction models for crack initiation

    NASA Technical Reports Server (NTRS)

    Halford, Gary R.

    1993-01-01

    The evolution of high-temperature, creep-fatigue, life-prediction methods used for cyclic crack initiation is traced from inception in the late 1940's. The methods reviewed are material models as opposed to structural life prediction models. Material life models are used by both structural durability analysts and by material scientists. The latter use micromechanistic models as guidance to improve a material's crack initiation resistance. Nearly one hundred approaches and their variations have been proposed to date. This proliferation poses a problem in deciding which method is most appropriate for a given application. Approaches were identified as being combinations of thirteen different classifications. This review is intended to aid both developers and users of high-temperature fatigue life prediction methods by providing a background from which choices can be made. The need for high-temperature, fatigue-life prediction methods followed immediately on the heels of the development of large, costly, high-technology industrial and aerospace equipment immediately following the second world war. Major advances were made in the design and manufacture of high-temperature, high-pressure boilers and steam turbines, nuclear reactors, high-temperature forming dies, high-performance poppet valves, aeronautical gas turbine engines, reusable rocket engines, etc. These advances could no longer be accomplished simply by trial and error using the 'build-em and bust-em' approach. Development lead times were too great and costs too prohibitive to retain such an approach. Analytic assessments of anticipated performance, cost, and durability were introduced to cut costs and shorten lead times. The analytic tools were quite primitive at first and out of necessity evolved in parallel with hardware development. After forty years more descriptive, more accurate, and more efficient analytic tools are being developed. These include thermal-structural finite element and boundary element

  1. Brief summary of the evolution of high-temperature creep-fatigue life prediction models for crack initiation

    NASA Astrophysics Data System (ADS)

    Halford, Gary R.

    1993-10-01

    The evolution of high-temperature, creep-fatigue, life-prediction methods used for cyclic crack initiation is traced from inception in the late 1940's. The methods reviewed are material models as opposed to structural life prediction models. Material life models are used by both structural durability analysts and by material scientists. The latter use micromechanistic models as guidance to improve a material's crack initiation resistance. Nearly one hundred approaches and their variations have been proposed to date. This proliferation poses a problem in deciding which method is most appropriate for a given application. Approaches were identified as being combinations of thirteen different classifications. This review is intended to aid both developers and users of high-temperature fatigue life prediction methods by providing a background from which choices can be made. The need for high-temperature, fatigue-life prediction methods followed immediately on the heels of the development of large, costly, high-technology industrial and aerospace equipment immediately following the second world war. Major advances were made in the design and manufacture of high-temperature, high-pressure boilers and steam turbines, nuclear reactors, high-temperature forming dies, high-performance poppet valves, aeronautical gas turbine engines, reusable rocket engines, etc. These advances could no longer be accomplished simply by trial and error using the 'build-em and bust-em' approach. Development lead times were too great and costs too prohibitive to retain such an approach. Analytic assessments of anticipated performance, cost, and durability were introduced to cut costs and shorten lead times. The analytic tools were quite primitive at first and out of necessity evolved in parallel with hardware development. After forty years more descriptive, more accurate, and more efficient analytic tools are being developed. These include thermal-structural finite element and boundary element

  2. Temperature-dependent shock initiation of TATB-based high explosives

    SciTech Connect

    Dallman, J.C.; Wackerle, J.

    1993-10-01

    The effects of temperature on the shock sensitivity of two TATB formulations PBX 9502 and LX-17 are studied over the temperature range {minus}54{degrees}C to 252{degrees}C. The shock Hugoniot curves over this same temperature range are developed. Thermal expansion properties and porosities are used to help determine the mechanisms of thermal sensitization. Impact sensitivities over the range from ambient to 300{degrees}C are reported. Analyses of these results imply that thermal sensitization is the result of purely chemical kinetics enhancement and intracrystalline hot-spot growth. Additional results on the ambient shock sensitivity of PBX 9502 and LX-17 following thermal cycling to 252{degrees}C and back to ambient is presented.

  3. Low temperature protects mammalian cells from apoptosis initiated by various stimuli in vitro

    SciTech Connect

    Sakurai, Toshiharu; Itoh, Katsuhiko; Liu Yu; Higashitsuji, Hiroaki; Sumitomo, Yasuhiko; Sakamaki, Kazuhiro; Fujita, Jun . E-mail: jfujita@virus.kyoto-u.ac.jp

    2005-10-01

    Mild hypothermia shows protective effects on patients with brain damage and cardiac arrest. To elucidate the molecular mechanisms underlying these effects, we examined the effects of low temperature (32 deg. C) on cells exposed to a variety of stress in vitro. We found that 32 deg. C suppressed induction of apoptosis by cytotoxic stimuli such as adriamycin, etoposide, thapsigargin, NaCl, H{sub 2}O{sub 2}, and anti-Fas antibody. In adriamycin-treated BALB/3T3 cells, the down-shift in temperature from 37 deg. C to 32 deg. C increased the Bcl-xL protein level and decreased the mRNA level of Puma and mitochondrial translocation of Bax, suppressing caspase-9-mediated apoptosis. Furthermore, the protein level and stability of p53 were decreased, and its nuclear export was increased concomitant with Mdm2 mRNA upregulation. The low temperature effect was not observed in p53 {sup -/-}/Mdm2 {sup -/-} mouse embryonic fibroblasts, suggesting that the effect is mediated by suppression of the p53 pathway. In contrast, while thapsigargin-induced apoptosis was suppressed by the low temperature, no effect on the p53 protein level was observed. Furthermore, the survival rate of p53 {sup -/-}/Mdm2 {sup -/-} cells exposed to thapsigargin was increased when cultured at 32 deg. C compared with 37 deg. C. In conclusion, mild hypothermia protects cells from a variety of stress by p53-dependent and p53-independent mechanisms.

  4. Adhesive for polyester films cures at room temperature, has high initial tack

    NASA Technical Reports Server (NTRS)

    Christian, C. M.; Fust, G. W.; Welchel, C. J.

    1966-01-01

    Quick room-temperature-cure adhesive bonds polyester-insulated flat electrical cables to metal surfaces and various other substrates. The bond strength of the adhesive may be considerably increased by first applying a commercially available polyamide primer to the polyester film.

  5. Inverse design of coolant flow passage shapes with partially fixed internal geometries

    NASA Astrophysics Data System (ADS)

    Kennon, S. R.; Dulikravich, G. S.

    1985-03-01

    A method has been developed for the design and analysis of complex coolant flow passage shapes in internally cooled turbine engines. The method is particularly applicable to turbine airfoil cascade inverse design but may also be applied to the design of other nonadiabatic boundaries such as missile cone tips and internal combustion engine cylinder. The method makes it possible to specify and fix the temperature or the heat flux at the turbine airfoil outer surface, together with the desired temperature at the coolant/blade interfaces. Coupled with an appropriate flow solver and stress analysis code, the method provides accurate estimates of the blade surface temperature and heat flux distribution in the coolant passage. A first order panel method is used to solve the Laplace equations for steady heat conduction within the solid portions of the hollow blade. In order to illustrate the efficiency of the method, numerical results are presented for the case of a turbine airfoil having three coolant holes. The discretized temperature contours for the inner and outer parts of the blade are illustrated in graphic form.

  6. Loss-of-coolant accident experiment at the AVR gas-cooled reactor

    SciTech Connect

    Cleveland, J.; Krueger, K.; Kernforschungsanlage Juelich G.m.b.H. . Arbeitsgemeinschaft Versuchsreaktor)

    1989-01-01

    Loss-of-coolant is one of the most severe accidents for a nuclear power plant. To demonstrate inherent safety characteristics incorporated into small High-Temperature Gas Cooled Reactor (HTGR) designs, loss-of-coolant accident (LOCA) simulation tests have been conducted with the German pebble-bed High-Temperature Reactor AVR. The AVR is the only nuclear power plant ever to have been intentionally subjected to LOCA conditions. The LOCA test was planned to create conditions that would exist if a rapid LOCA occurred with the reactor operating at full power. The tests demonstrated this reactor's safe response to an accident in which the coolant escapes from the reactor core and no emergency system is available to provide coolant flow to the core. The test is of special interest because it demonstrates the inherent safety features incorporated into modular HTGR designs. The main LOCA test lasted for 5 d. After the test began, core temperatures increased for {approximately}13 h and then gradually and continually decreased as the rate of heat dissipation from the core exceeded accident levels of decay power. Throughout the test, temperatures remained below limiting values for the core and other reactor components. 3 refs., 9 figs., 1 tab.

  7. Loss-of-coolant accident experiment at the AVR (Arbeitsgemeinschaft Versuchsreaktor) gas-cooled reactor

    SciTech Connect

    Krueger, K. ); Cleveland, J. )

    1989-11-01

    Loss of coolant is one of the most severe accidents for a nuclear power plant. To demonstrate inherent safety characteristics incorporated into modular gas-cooled reactor designs, loss-of-coolant accident (LOCA) simulation tests were conducted with the 15-MW(electric), 46-MW(thermal), pebble-bed, high-temperature Arbeitsgemeinschaft Versuchsreaktor (AVR) in the Federal Republic of Germany (FRG). This is the only nuclear power plant ever to have been intentionally subjected to LOCa conditions. Oak Ridge National Laboratory participation in the preparation and conduct of the tests was carried out within the U.S./FRG Agreement for Cooperation in Gas-Cooled Reactor Development.

  8. Study of coolant activation and dose rates with flow rate and power perturbations in pool-type research reactors

    SciTech Connect

    Mirza, N.M.; Mirza, S.M.; Ahmad, N. )

    1991-12-01

    This paper reports on a computer code using the multigroup diffusion theory based LEOPARD and ODMUG programs that has been developed to calculate the activity in the coolant leaving the core of a pool-type research reactor. Using this code, the dose rates at various locations along the coolant path with varying coolant flow rate and reactor power perturbations are determined. A flow rate decrease from 1000 to 145 m{sup 3}/h is considered. The results indicate that a flow rate decrease leads to an increase in the coolant outlet temperature, which affects the neutron group constants and hence the group fluxes. The activity in the coolant leaving the core increases with flow rate decrease. However, at the inlet of the holdup tank, the total dose rate first increases, then passes through a maximum at {approximately} 500 m{sup 3}/h, and finally decreases with flow rate decrease. The activity at the outlet of the holdup tank is mainly due to {sup 24}Na and {sup 56}Mn, and it increases by {approximately} 2% when the flow rate decreases from 1000 to 145 m{sup 3}/h. In an accidental power rise at constant flow rate, the activity in the coolant increases, and the dose rates at all the points along the coolant path show a slight nonlinear rise as the reactor power density increases.

  9. New Configurations of Micro Plate-Fin Heat Sink to Reduce Coolant Pumping Power

    NASA Astrophysics Data System (ADS)

    Rezania, A.; Rosendahl, L. A.

    2012-06-01

    The thermal resistance of heat exchangers has a strong influence on the electric power produced by a thermoelectric generator (TEG). In this work, a real TEG device is applied to three configurations of micro plate-fin heat sink. The distance between certain microchannels is varied to find the optimum heat sink configuration. The particular focus of this study is to reduce the coolant mass flow rate by considering the thermal resistances of the heat sinks and, thereby, to reduce the coolant pumping power in the system. The three-dimensional governing equations for the fluid flow and the heat transfer are solved using the finite-volume method for a wide range of pressure drop laminar flows along the heat sink. The temperature and the mass flow rate distribution in the heat sink are discussed. The results, which are in good agreement with previous computational studies, show that using suggested heat sink configurations reduces the coolant pumping power in the system.

  10. Modelling of heat transfer in composite bodies reinforced with tubes with incompressible liquid coolant moving in laminar regime

    NASA Astrophysics Data System (ADS)

    Yankovskii, A. P.

    2015-01-01

    The equations were obtained for description of heat transfer in composite bodies with reinforcement with a set of smooth tubes with pumping of incompressible liquid coolant. The appropriate boundary-value problem of heat transfer was formulated with the following qualitative analysis. The steady temperature fields in cylindrical shells with spiral-shaped tube reinforcement (with liquid coolant flow) were simulated. The influence on the temperature fields from the side of reinforcement geometry parameters, flow direction and velocity, tubes cross sections was studied. It was found that these characteristics allow significant variation of temperature field in its gradients within the composite item: this open ways for effective control of temperature fields.

  11. Initial stages of gold adsorption on silicon stepped surface at elevated temperatures

    SciTech Connect

    Kosolobov, S. S. Song, Se Ahn; Rodyakina, E. E.; Latyshev, A. V.

    2007-04-15

    Experimental study performed by ultrahigh vacuum reflection electron microscopy and atomic force microscopy reveals step instability on Si(111) surface during gold deposition at elevated temperatures (higher than 900 deg. C). Our results show that transformations of regular atomic steps into the system of step bunches and vice versa depend on the gold coverage and direction of the electrical current heating the sample. The mechanism and conditions of the surface morphology transformations are discussed.

  12. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-08-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  13. Carrier interactions and porosity initiated reversal of temperature dependence of thermal conduction in nanoscale tin films

    SciTech Connect

    Kaul, Pankaj B.; Prakash, Vikas

    2014-01-14

    Recently, tin has been identified as an attractive electrode material for energy storage/conversion technologies. Tin thin films have also been utilized as an important constituent of thermal interface materials in thermal management applications. In this regards, in the present paper, we investigate thermal conductivity of two nanoscale tin films, (i) with thickness 500 ± 50 nm and 0.45% porosity and (ii) with thickness 100 ± 20 nm and 12.21% porosity. Thermal transport in these films is characterized over the temperature range from 40 K–310 K, using a three-omega method for multilayer configurations. The experimental results are compared with analytical predictions obtained by considering both phonon and electron contributions to heat conduction as described by existing frequency-dependent phenomenological models and BvK dispersion for phonons. The thermal conductivity of the thicker tin film (500 nm) is measured to be 46.2 W/m-K at 300 K and is observed to increase with reduced temperatures; the mechanisms for thermal transport are understood to be governed by strong phonon-electron interactions in addition to the normal phonon-phonon interactions within the temperature range 160 K–300 K. In the case of the tin thin film with 100 nm thickness, porosity and electron-boundary scattering supersede carrier interactions, and a reversal in the thermal conductivity trend with reduced temperatures is observed; the thermal conductivity falls to 1.83 W/m-K at 40 K from its room temperature value of 36.1 W/m-K. In order to interpret the experimental results, we utilize the existing analytical models that account for contributions of electron-boundary scattering using the Mayadas-Shatzkes and Fuchs-Sondheimer models for the thin and thick films, respectively. Moreover, the effects of porosity on carrier transport are included using a previous treatment based on phonon radiative transport involving frequency-dependent mean free paths

  14. Effect of initial gamma prime size on the elevated temperature creep properties of single crystal nickel base superalloys

    NASA Technical Reports Server (NTRS)

    Nathal, M. V.

    1987-01-01

    The influence of initial gamma-prime size and shape on the high-temperature creep properties of two single-crystal Ni-base superalloys was investigated. The two alloys were chosen to represent different magnitudes of gamma/gamma-prime lattice mismatch. A range of initial microstructures was produced by various quenching and aging treatments. Creep-rupture testing at 1000 C was performed under stresses where gamma-prime directionally coarsens to form gamma/gamma-prime lamellae in the early portion of the creep life. Both alloys exhibited a peak in creep resistance as a function of initial gamma-prime size. The peak corresponded to an initial microstructure consisting of cuboidal precipitates aligned along 001 line directions. These aligned cuboidal gamma-prime particles directionally coarsened into a relatively perfect lamellar gamma/gamma-prime structure in the early stages of creep, whereas the more irregularly shaped and distributed gamma-prime particles in both under- and overaged material formed more irregular lamellae with more imperfections. The alloy with a lower magnitude of mismatch was less sensitive to initial gamma-prime size and shape.

  15. Evaluation of engine coolant recycling processes: Part 2

    SciTech Connect

    Bradley, W.H.

    1999-08-01

    Engine coolant recycling continues to provide solutions to both economic and environmental challenges often faced with the disposal of used engine coolant. General Motors` Service Technology Group (STG), in a continuing effort to validate the general practice of recycling engine coolants, has conducted an in-depth study on the capabilities of recycled coolants. Various recycling processes ranging from complex forms of fractional distillation to simple filtration were evaluated in this study to best represent the current state of coolant recycling technology. This study incorporates both lab and (limited) fleet testing to determine the performance capabilities of the recycled coolants tested. While the results suggest the need for additional studies in this area, they reveal the true capabilities of all types of engine coolant recycling technologies.

  16. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    SciTech Connect

    Su'ud, Zaki; Anshari, Rio

    2012-06-06

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  17. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Su'ud, Zaki; Anshari, Rio

    2012-06-01

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  18. Investigating Liquid CO2 as a Coolant for a MTSA Heat Exchanger Design

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Padilla, Sebastian; Powers, Aaron; Iacomini, Christie

    2009-01-01

    Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO 2) control for a future Portable Life Support System (PLSS), as well as water recycling. CO 2 removal and rejection is accomplished by driving a sorbent through a temperature swing of approximately 210 K to 280 K . The sorbent is cooled to these sub-freezing temperatures by a Sublimating Heat Exchanger (SHX) with liquid coolant expanded to sublimation temperatures. Water is the baseline coolant available on the moon, and if used, provides a competitive solution to the current baseline PLSS schematic. Liquid CO2 (LCO2) is another non-cryogenic coolant readily available from Martian resources which can be produced and stored using relatively low power and minimal infrastructure. LCO 2 expands from high pressure liquid (5800 kPa) to Mars ambient (0.8 kPa) to produce a gas / solid mixture at temperatures as low as 156 K. Analysis and experimental work are presented to investigate factors that drive the design of a heat exchanger to effectively use this sink. Emphasis is given to enabling efficient use of the CO 2 cooling potential and mitigation of heat exchanger clogging due to solid formation. Minimizing mass and size as well as coolant delivery are also considered. The analysis and experimental work is specifically performed in an MTSA-like application to enable higher fidelity modeling for future optimization of a SHX design. In doing so, the work also demonstrates principles and concepts so that the design can be further optimized later in integrated applications (including Lunar application where water might be a choice of coolant).

  19. Temperature-Sensitive Divisionless Mutant of Bacillus subtilis Defective in the Initiation of Septation

    PubMed Central

    Breakefield, Xandra O.; Landman, Otto E.

    1973-01-01

    A temperature-sensitive divisionless mutant of Bacillus subtilis 168, tms-12, is shown to be defective in an early step in septum formation at the restrictive temperature. The nature of this defect has been studied by comparing the growth and composition of mutant and wild-type (tms-12+) cells at the restrictive (48 C) and permissive (34 C) temperatures. At 48 C, tms-12 cells grow as nonseptate, multinucleate filaments. Filamentation does not appear to be a result of alterations in properties of the cell wall, since the ratio of mucopeptide to teichoic acid, the autolytic activity, and the ability of the walls to protect cells against osmotic shock are comparable in tms-12 filaments and tms-12+ bacilli grown at 48 C. Synthesis of deoxyribonucleic acid and the segregation of nucleoids also proceed normally during filamentation. The synthesis of membrane, however, is delayed during filamentation of tms-12. No gross alterations were observed in the protein or lipid composition of membranes isolated from mutant filaments. Septum formation resumes when filaments are returned to 34 C and appears to be associated with an increased synthesis of membrane. The occurrence of septa was monitored both by microscopic observation of cross walls and by assays of the number of viable protoplasts released from bacillary filaments upon removal of the cell wall. Septation recovery can be blocked by inhibitors of ribonucleic acid and protein synthesis added during, but not after, the first 7 min of recovery at 34 C. By contrast, inhibition of deoxyribonucleic synthesis does not block recovery. Images PMID:4570614

  20. TACT 1: A computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 2. Programmers manual

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1979-01-01

    A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled axial flow turbine blade or vane with an impingement insert is described. Coolant-side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in a chordwise direction and is discharged through the trailing edge and through film cooling holes. The ability of the program to handle film cooling is limited by the internal flow model. Input to the program includes a description of the blade geometry, coolant-supply conditions, outside thermal boundary conditions, and wheel speed. The blade wall can have two layers of different materials, such as a ceramic thermal barrier coating over a metallic substrate. Program output includes the temperature at each node, the coolant pressures and flow rates, and the coolant-side heat transfer coefficients.

  1. Characterization of an urban-rural CO 2 /temperature gradient and associated changes in initial plant productivity during secondary succession

    SciTech Connect

    Ziska, L. H.; Bunce, J. A.; Goins, E. W.

    2004-05-01

    To examine the impact of climate change on vegetative productivity, we exposed fallow agricultural soil to an in situ temperature and CO2 gradient between urban, suburban and rural areas in 2002. Along the gradient, average daytime CO2 concentration increased by 21% and maximum (daytime) and minimum (nighttime) daily temperatures increased by 1.6 and 3.3°C, respectively in an urban relative to a rural location. Consistent location differences in soil temperature were also ascertained. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented. The urban-induced environmental changes that were observed were consistent with most short-term (~50 year) global change scenarios regarding CO2 concentration and air temperature. Productivity, determined as final above-ground biomass, and maximum plant height were positively affected by daytime and soil temperatures as well as enhanced [CO2], increasing 60 and 115% for the suburban and urban sites, respectively, relative to the rural site. While long-term data are needed, these initial results suggest that urban environments may act as a reasonable surrogate for investigating future climatic change in vegetative communities.

  2. Low-temperature combustion chemistry of biofuels: pathways in the initial low-temperature (550 K-750 K) oxidation chemistry of isopentanol.

    PubMed

    Welz, Oliver; Zádor, Judit; Savee, John D; Ng, Martin Y; Meloni, Giovanni; Fernandes, Ravi X; Sheps, Leonid; Simmons, Blake A; Lee, Taek Soon; Osborn, David L; Taatjes, Craig A

    2012-03-01

    The branched C(5) alcohol isopentanol (3-methylbutan-1-ol) has shown promise as a potential biofuel both because of new advanced biochemical routes for its production and because of its combustion characteristics, in particular as a fuel for homogeneous-charge compression ignition (HCCI) or related strategies. In the present work, the fundamental autoignition chemistry of isopentanol is investigated by using the technique of pulsed-photolytic Cl-initiated oxidation and by analyzing the reacting mixture by time-resolved tunable synchrotron photoionization mass spectrometry in low-pressure (8 Torr) experiments in the 550-750 K temperature range. The mass-spectrometric experiments reveal a rich chemistry for the initial steps of isopentanol oxidation and give new insight into the low-temperature oxidation mechanism of medium-chain alcohols. Formation of isopentanal (3-methylbutanal) and unsaturated alcohols (including enols) associated with HO(2) production was observed. Cyclic ether channels are not observed, although such channels dominate OH formation in alkane oxidation. Rather, products are observed that correspond to formation of OH viaβ-C-C bond fission pathways of QOOH species derived from β- and γ-hydroxyisopentylperoxy (RO(2)) radicals. In these pathways, internal hydrogen abstraction in the RO(2)⇄ QOOH isomerization reaction takes place from either the -OH group or the C-H bond in α-position to the -OH group. These pathways should be broadly characteristic for longer-chain alcohol oxidation. Isomer-resolved branching ratios are deduced, showing evolution of the main products from 550 to 750 K, which can be qualitatively explained by the dominance of RO(2) chemistry at lower temperature and hydroxyisopentyl decomposition at higher temperature. PMID:22286869

  3. Crack initiation behavior of neutron irradiated model and commercial stainless steels in high temperature water

    NASA Astrophysics Data System (ADS)

    Stephenson, Kale J.; Was, Gary S.

    2014-01-01

    The objective of this study was to isolate key factors affecting the irradiation-assisted stress corrosion cracking (IASCC) susceptibility of eleven neutron-irradiated austenitic stainless steel alloys. Four commercial purity and seven high purity stainless steels were fabricated with specific changes in composition and microstructure, and irradiated in a fast reactor spectrum at 320 °C to doses between 4.4 and 47.5 dpa. Constant extension rate tensile (CERT) tests were performed in normal water chemistry (NWC), hydrogen water chemistry (HWC), or primary water (PW) environments to isolate the effects of environment, elemental solute addition, alloy purity, alloy heat, alloy type, cold work, and irradiation dose. The irradiated alloys showed a wide variation in IASCC susceptibility, as measured by the relative changes in mechanical properties and crack morphology. Cracking susceptibility measured by %IG was enhanced in oxidizing environments, although testing in the lowest potential environment caused an increase in surface crack density. Alloys containing solute addition of Ni or Ni + Cr exhibited no IASCC. Susceptibility was reduced in materials cold worked prior to irradiation, and increased with increasing irradiation dose. Irradiation-induced hardening was accounted for by the dislocation loop microstructure, however no relation between crack initiation and radiation hardening was found.

  4. Interactive initialization of heat flux parameters for numerical models using satellite temperature measurements. [Kansas and Indiana

    NASA Technical Reports Server (NTRS)

    Carlson, T. N. (Principal Investigator)

    1982-01-01

    A method for obtaining patterns of moisture availability (and net evaporation) from satellite infrared measurements employs Carlson's boundary layer model and a variety of image processing routines executed by a minicomputer. To test the method with regard to regional scale moisture analyses, two case studies were chosen because of the availability of HCMM data and because of the presence of a large horizontal gradient in antecedent precipitation and crp moisture index. Results show some correlation in both cases between antecedent precipitation and derived moisture availability. Apparently, regional-scale moisture availability patterns can be determined with some degree of fidelity but the values themselves may be useful only in the relative sense and significant to within plus or minus one category of dryness over a range of 4 or 5 categories between absolutely dry and field saturation. Preliminary results suggest that the derived moisture values correlate best with longer-term precipitation totals, suggesting that the infrared temperatures respond more sensitively to a relatively deep substrate layer.

  5. Cryogenic-coolant He-4-superconductor interaction

    NASA Technical Reports Server (NTRS)

    Caspi, S.; Lee, J. Y.; Kim, Y. I.; Allen, R. J.; Frederking, T. H. K.

    1978-01-01

    The thermodynamic and thermal interaction between a type 2 composite alloy and cryo-coolant He4 was studied with emphasis on post quench phenomena of formvar coated conductors. The latter were investigated using a heater simulation technique. Overall heat transfer coefficients were evaluated for the quench onset point. Heat flux densities were determined for phenomena of thermal switching between a peak and a recovery value. The study covered near saturated liquid, pressurized He4, both above and below the lambda transition, and above and below the thermodynamic critical pressure. In addition, friction coefficients for relative motion between formvar insulated conductors were determined.

  6. Secondary coolant circuit for nuclear-reactors

    SciTech Connect

    Brachet, A.

    1981-10-06

    A secondary coolant circuit for a nuclear-reactor of the liquid metal cooled type is described. The circuit comprises at least one intermediate exchanger mounted in the vessel of said reactor, Also included is a steam-generator for the exchange of calories between the secondary liquid-metal flowing through said secondary circuit and water-steam, at least one pump for circulating said secondary sodium and one tank for storing said secondary liquid-metal andrecovering those products generated by a possible liquid-metal-water reaction in said steam-generator.

  7. Nuclear fuel assembly with coolant conducting tube

    SciTech Connect

    Dunlap, T. G.; Cearley, J. E.; Jameson, W. G. Jr.; Mefford, C. R.; Nelson, H. L.

    1983-12-13

    In a nuclear fuel assembly having a coolant conducting or water tube which also retains the spacers in axial position, the fuel rods experience greater axial growth with exposure than the water tube creating a risk that the water tube might become disengaged from the supporting tie plates. An arrangement for preventing such disengagement is described including lengthened end plug shanks for the water tube, a protective boss surrounding the lower end plug shank to protect it from flow induced vibration, a conical seat for the lower end plug and an arrangement for limiting upward movement of the water tube.

  8. Fleet test evaluation of fully formulated heavy-duty coolant technology maintained with a delayed-release filter compared with coolant inhibited with a nitrited organic acid technology: An interim report

    SciTech Connect

    Aroyan, S.S.; Eaton, E.R.

    1999-08-01

    This paper is a controlled extended service interval (ESI) study of the comparative behaviors of a nitrite/borate/low-silicate, low total dissolved solids (TDS) coolant maintained with delayed-release filters, and an organic acid inhibited coolant technology in heavy-duty engines. It reports both laboratory and fleet test data from 66 trucks, powered with different makes of heavy-duty diesel engines. The engines were cooled with three different types of inhibitors and two different glycol base (ethylene glycol and propylene glycol) coolants for an initial period exceeding two years and 500,000 km (300,000 miles). The data reported include chemical depletion rates, periodic coolant chemical analyses, and engine/cooling system reliability experience. The ongoing test will continue for approximately five years and a 1.6 million km (1 million miles) duration. Thirteen trucks were retained as controls, operating with ASTM D 4985 specification (GM-6038 type) coolant maintained with a standard ASTM D 57542 supplemental coolant additive (SCA). Engines produced by Caterpillar, Detroit Diesel Corp., Cummins Engine Co., and Mack Trucks are included in the test mix.

  9. Lead Coolant Test Facility Systems Design, Thermal Hydraulic Analysis and Cost Estimate

    SciTech Connect

    Soli Khericha; Edwin Harvego; John Svoboda; Ryan Dalling

    2012-01-01

    The Idaho National Laboratory prepared a preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed: (1) Develop and Demonstrate Feasibility of Submerged Heat Exchanger; (2) Develop and Demonstrate Open-lattice Flow in Electrically Heated Core; (3) Develop and Demonstrate Chemistry Control; (4) Demonstrate Safe Operation; and (5) Provision for Future Testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimate. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.

  10. Nanosecond laser-induced damage at different initial temperatures of Ta{sub 2}O{sub 5} films prepared by dual ion beam sputtering

    SciTech Connect

    Xu, Cheng Jia, Jiaojiao; Fan, Heliang; Qiang, Yinghuai; Liu, Jiongtian; Yang, Di; Hu, Guohang; Li, Dawei

    2014-08-07

    Ta{sub 2}O{sub 5} films were deposited by dual ion beam sputtering method. The nanosecond laser-induced damage threshold (LIDT) at different initial temperatures and time of the films was investigated by an in situ high temperature laser-induced damage testing platform. It was shown that, when the initial temperature increased from 298 K to 383 K, the LIDT at 1064 nm and 12 ns significantly decreased by nearly 14%. Then the LIDT at 1064 nm and 12 ns decreased slower with the same temperature increment. Different damage morphologies were found at different initial temperatures. At low initial temperatures, it was the defects-isolated damage while at high initial temperatures it was the defects-combined damage. The theoretical calculations based on the defect-induced damage model revealed that both the significant increase of the highest temperature and the duration contributed to the different damage morphologies. With the initial temperature being increased, the thermal-stress coupling damage mechanism transformed gradually to the thermal dominant damage mechanism.

  11. Sensitivity of high-temperature weather to initial soil moisture: a case study with the WRF model

    NASA Astrophysics Data System (ADS)

    Zeng, X.-M.; Wang, B.; Zhang, Y.; Song, S.; Huang, X.; Zheng, Y.; Chen, C.; Wang, G.

    2014-05-01

    Using the Weather Research and Forecasting model (WRF), we investigate the sensitivity of simulated short-range high-temperature weather to initial soil moisture for the East China extremely hot event in late July 2003 via a succession of 24 h simulations. The initial soil moisture (SMOIS) in the Noah land surface scheme is prescribed for five groups of designed simulations, i.e., relative to the control run (CTL), SMOIS is changed by -25, -50, +25 and +50% in the DRY25, DRY50, WET25 and WET50 groups, respectively, with ten 24 h-long integrations performed in each group. We focus on above-35 °C (standard of so-called "high-temperature" event in China) 2 m surface air temperature (SAT) at 06:00 UTC (roughly 12:00 LT in the study domain) to analyze the occurrence of the high-temperature event. Ten-day mean results show that the 06:00 UTC SAT (SAT06) is sensitive to the SMOIS change, i.e., SAT06 exhibits an apparent rising with the SMOIS decrease (e.g., compared with CTL, DRY25 results in a 1 °C SAT06 rising in general over land surface of East China), areas with above-35 °C SAT06 are most affected, and the simulations are found to be more sensitive to the SMOIS decrease than to the SMOIS increase, suggesting that hot weather can be amplified under low soil moisture conditions. With regard to the mechanism of influencing the extreme high SAT06, sensible heat flux shows to directly heat the lower atmosphere, latent heat flux is found to be more sensitive to the SMOIS change and results in the overall increase of surface net radiation due to the increased greenhouse effect (e.g., with the SMOIS increase of 25% from DRY25 to CTL, the ten-day mean net radiation is increased by 5 W m-2), and a negative (positive) feedback is found between regional atmospheric circulation and air temperature in the lower atmosphere (mid-troposphere) due to the unique dynamic nature of the western Pacific subtropical high. Using a method based on an analogous temperature relationship, a

  12. Initial stages of growth and the influence of temperature during chemical vapor deposition of sp{sup 2}-BN films

    SciTech Connect

    Chubarov, Mikhail; Pedersen, Henrik; Högberg, Hans; Henry, Anne; Czigány, Zsolt

    2015-11-15

    Knowledge of the structural evolution of thin films, starting by the initial stages of growth, is important to control the quality and properties of the film. The authors present a study on the initial stages of growth and the temperature influence on the structural evolution of sp{sup 2} hybridized boron nitride (BN) thin films during chemical vapor deposition (CVD) with triethyl boron and ammonia as precursors. Nucleation of hexagonal BN (h-BN) occurs at 1200 °C on α-Al{sub 2}O{sub 3} with an AlN buffer layer (AlN/α-Al{sub 2}O{sub 3}). At 1500 °C, h-BN grows with a layer-by-layer growth mode on AlN/α-Al{sub 2}O{sub 3} up to ∼4 nm after which the film structure changes to rhombohedral BN (r-BN). Then, r-BN growth proceeds with a mixed layer-by-layer and island growth mode. h-BN does not grow on 6H-SiC substrates; instead, r-BN nucleates and grows directly with a mixed layer-by-layer and island growth mode. These differences may be caused by differences in substrate surface temperature due to different thermal conductivities of the substrate materials. These results add to the understanding of the growth process of sp{sup 2}-BN employing CVD.

  13. Fabrication and Characterization of a Porous Silicon Drug Delivery System with an Initiated Chemical Vapor Deposition Temperature-Responsive Coating.

    PubMed

    McInnes, Steven J P; Szili, Endre J; Al-Bataineh, Sameer A; Vasani, Roshan B; Xu, Jingjing; Alf, Mahriah E; Gleason, Karen K; Short, Robert D; Voelcker, Nicolas H

    2016-01-12

    This paper reports on the fabrication of a pSi-based drug delivery system, functionalized with an initiated chemical vapor deposition (iCVD) polymer film, for the sustainable and temperature-dependent delivery of drugs. The devices were prepared by loading biodegradable porous silicon (pSi) with a fluorescent anticancer drug camptothecin (CPT) and coating the surface with temperature-responsive poly(N-isopropylacrylamide-co-diethylene glycol divinyl ether) (pNIPAM-co-DEGDVE) or non-stimulus-responsive poly(aminostyrene) (pAS) via iCVD. CPT released from the uncoated oxidized pSi control with a burst release fashion (∼21 nmol/(cm(2) h)), and this was almost identical at temperatures both above (37 °C) and below (25 °C) the lower critical solution temperature (LCST) of the switchable polymer used, pNIPAM-co-DEGDVE (28.5 °C). In comparison, the burst release rate from the pSi-pNIPAM-co-DEGDVE sample was substantially slower at 6.12 and 9.19 nmol/(cm(2) h) at 25 and 37 °C, respectively. The final amount of CPT released over 16 h was 10% higher at 37 °C compared to 25 °C for pSi coated with pNIPAM-co-DEGDVE (46.29% vs 35.67%), indicating that this material can be used to deliver drugs on-demand at elevated temperatures. pSi coated with pAS also displayed sustainable drug delivery profiles, but these were independent of the release temperature. These data show that sustainable and temperature-responsive delivery systems can be produced by functionalization of pSi with iCVD polymer films. Benefits of the iCVD approach include the application of the iCVD coating after drug loading without causing degradation of the drug commonly caused by exposure to factors such as solvents or high temperatures. Importantly, the iCVD process is applicable to a wide array of surfaces as the process is independent of the surface chemistry and pore size of the nanoporous matrix being coated. PMID:26654169

  14. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    SciTech Connect

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; Violi, Angela; Taatjes, Craig A.

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  15. Sensitivity of high-temperature weather to initial soil moisture: a case study using the WRF model

    NASA Astrophysics Data System (ADS)

    Zeng, X.-M.; Wang, B.; Zhang, Y.; Song, S.; Huang, X.; Zheng, Y.; Chen, C.; Wang, G.

    2014-09-01

    Using a succession of 24 h Weather Research and Forecasting model (WRF) simulations, we investigate the sensitivity to initial soil moisture of a short-range high-temperature weather event that occurred in late July 2003 in East China. The initial soil moisture (SMOIS) in the Noah land surface scheme is adjusted (relative to the control run, CTL) for four groups of simulations: DRY25 (-25%), DRY50 (-50%), WET25 (+25%) and WET50 (+50%). Ten 24 h integrations are performed in each group. We focus on 2 m surface air temperature (SAT) greater than 35 °C (the threshold of "high-temperature" events in China) at 06:00 UTC (roughly 14:00 LT in the study domain) to analyse the occurrence of the high-temperature event. The 10-day mean results show that the 06:00 UTC SAT (SAT06) is sensitive to the SMOIS change; specifically, SAT06 exhibits an apparent increase with the SMOIS decrease (e.g. compared with CTL, DRY25 generally results in a 1 °C SAT06 increase over the land surface of East China), areas with 35 °C or higher SAT06 are the most affected, and the simulations are more sensitive to the SMOIS decrease than to the SMOIS increase, which suggests that hot weather can be amplified under low soil moisture conditions. Regarding the mechanism underlying the extremely high SAT06, sensible heat flux has been shown to directly heat the lower atmosphere, and latent heat flux has been found to be more sensitive to the SMOIS change, resulting in an overall increase in surface net radiation due to the increased greenhouse effect (e.g. with the SMOIS increase from DRY25 to CTL, the 10-day mean net radiation increases by 5 W m-2). Additionally, due to the unique and dynamic nature of the western Pacific subtropical high, negative feedback occurs between the regional atmospheric circulation and the air temperature in the lower atmosphere while positive feedback occurs in the mid-troposphere. Using a method based on an analogous temperature relationship, a detailed analysis of the

  16. Analysis of coolant flow and heat transfer in the SSME HPOTP Number 4 bearing assembly

    NASA Technical Reports Server (NTRS)

    Owens, S. F.; Costes, N. C.

    1990-01-01

    The PHOENICS code has been applied to simulate the flow of liquid oxygen through the number 4 ball bearing assembly of the Space Shuttle Main Engine High-Pressure Oxidizer Turbopump. The Body-Fitted Coordinate system capability of PHOENICS was utilized to create a geometrically accurate model. Effects accounted for by the model include the rotation rate of the calculation domain, viscous heating in the liquid oxygen and two-phase effects due to LOX boiling. A separation program was used to account for conduction within a ball bearing element which was coupled with the PHOENICS flow and heat transfer analysis. Solutions have been obtained for the velocity and temperature fields within the LOX coolant and the temperature within the ball element. The predicted ball temperatures indicate that the coolant is boiling in the region near the ball surface.

  17. Large break loss of coolant severe accident sequences at the HFIR (High Flux Isotope Reactor)

    SciTech Connect

    Simpson, D.B.; Greene, S.R.

    1990-01-01

    An assessment of many potential HFIR severe accident phenomena was conducted during the HFIR design effort, and many severe accident mitigating features were designed into the plant. These evaluation typically incorporated a bounding'' or highly conservative analysis approach and employed tools and techniques representative of the state of knowledge in the mid-1960s. Recently, programs to address severe accident issues were initiated at the Oak Ridge National Laboratory (ORNL) to support the HFIR probabilistic risk assessment (PRA) and equipment qualification and accident management studies. This paper presents the results of environment condition calculations conducted to evaluate a response of HFIR's heat exchanger cell environment to a double-ended rupture of a 0.25 m diameter coolant loop downstream of the circulating pump and check valve. The confinement calculations were performed using an atmospheric fission product source for the heat exchanger cell consistent with, but more conservative than that stipulated in Regulatory Guide 1.89. The results of the calculations indicate that the heat exchanger cell atmospheric temperature peaks at 377 K 225 seconds into the transient and then begins decreasing at approximately 1.7 K per minute. 8 refs., 5 figs.

  18. Aging and loss-of-coolant accident (LOCA) testing of electrical connections

    SciTech Connect

    Nelson, C.F.

    1998-01-01

    This report presents the results of an experimental program to determine the aging and loss-of-coolant accident (LOCA) behavior of electrical connections in order to obtain an initial scoping of their performance. Ten types of connections commonly used in nuclear power plants were tested. These included 3 types of conduit seals, 2 types of cable-to-device connectors, 3 types of cable-to-cable connectors, and 2 types of in-line splices. The connections were aged for 6 months under simultaneous thermal (99 C) and radiation (46 Gy/hr) conditions. A simulated LOCA consisting of sequential high dose-rate irradiation (3 kGy/hr) and high-temperature steam exposures followed the aging. Connection functionality was monitored using insulation resistance measurements during the aging and LOCA exposures. Because only 5 of the 10 connection types passed a post-LOCA, submerged dielectric withstand test, further detailed investigation of electrical connections and the effects of cable jacket integrity on the cable-connection system is warranted.

  19. Plasma-initiated rehydrogenation of amorphous silicon to increase the temperature processing window of silicon heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Shi, Jianwei; Boccard, Mathieu; Holman, Zachary

    2016-07-01

    The dehydrogenation of intrinsic hydrogenated amorphous silicon (a-Si:H) at temperatures above approximately 300 °C degrades its ability to passivate silicon wafer surfaces. This limits the temperature of post-passivation processing steps during the fabrication of advanced silicon heterojunction or silicon-based tandem solar cells. We demonstrate that a hydrogen plasma can rehydrogenate intrinsic a-Si:H passivation layers that have been dehydrogenated by annealing. The hydrogen plasma treatment fully restores the effective carrier lifetime to several milliseconds in textured crystalline silicon wafers coated with 8-nm-thick intrinsic a-Si:H layers after annealing at temperatures of up to 450 °C. Plasma-initiated rehydrogenation also translates to complete solar cells: A silicon heterojunction solar cell subjected to annealing at 450 °C (following intrinsic a-Si:H deposition) had an open-circuit voltage of less than 600 mV, but an identical cell that received hydrogen plasma treatment reached a voltage of over 710 mV and an efficiency of over 19%.

  20. Flibe use in fusion reactors -- An initial safety assessment

    SciTech Connect

    Cadwallader, L.C.; Longhurst, G.R.

    1999-03-01

    This report is an initial effort to identify and evaluate safety issues associated with the use of Flibe (LiF-BeF{sub 2}) as a molten salt coolant for nuclear fusion power plant applications. Flibe experience in the Molten Salt Reactor Experiment is briefly reviewed. Safety issues identified include chemical toxicity, radiological issues resulting from neutron activation, and the operational concerns of handling a high temperature coolant. Beryllium compounds and fluorine pose be toxicological concerns. Some controls to protect workers are discussed. Since Flibe has been handled safely in other applications, its hazards appear to be manageable. Some safety issues that require further study are pointed out. Flibe salt interaction with strong magnetic fields should be investigated. Evolution of Flibe constituents and activation products at high temperature (i.e., will Fluorine release as a gas or remain in the molten salt) is an issue. Aerosol and tritium release from a Flibe spill requires study, as does neutronics analysis to characterize radiological doses. Tritium migration from Flibe into the cooling system is also a safety concern. Investigation of these issues will help determine the extent to which Flibe shows promise as a fusion power plant coolant or plasma-facing material.

  1. Flibe Use in Fusion Reactors - An Initial Safety Assessment

    SciTech Connect

    Cadwallader, Lee Charles; Longhurst, Glen Reed

    1999-04-01

    This report is an initial effort to identify and evaluate safety issues associated with the use of Flibe (LiF-BeF2) as a molten salt coolant for nuclear fusion power plant applications. Flibe experience in the Molten Salt Reactor Experiment is briefly reviewed. Safety issues identified include chemical toxicity, radiological issues resulting from neutron activation, and the operational concerns of handling a high temperature coolant. Beryllium compounds and fluorine pose be toxicological concerns. Some controls to protect workers are discussed. Since Flibe has been handled safely in other applications, its hazards appear to be manageable. Some safety issues that require further study are pointed out. Flibe salt interaction with strong magnetic fields should be investigated. Evolution of Flibe constituents and activation products at high temperature (i.e., will Fluorine release as a gas or remain in the molten salt) is an issue. Aerosol and tritium release from a Flibe spill requires study, as does neutronics analysis to characterize radiological doses. Tritium migration from Flibe into the cooling system is also a safety concern. Investigation of these issues will help determine the extent to which Flibe shows promise as a fusion power plant coolant or plasma-facing material.

  2. Effect of glycol-based coolants on the suppression and recovery of platinum fuel cell electrocatalysts

    NASA Astrophysics Data System (ADS)

    Garsany, Yannick; Dutta, Sreya; Swider-Lyons, Karen E.

    2012-10-01

    We use cyclic and rotating disk electrode voltammetry to study glycol-based coolant formulations to show that individual constituents have either negligible or significant poisoning effects on the nanoscale Pt/carbon catalysts used in proton exchange membrane fuel cells. The base fluid in all these coolants is glycol (1, 3 propanediol), commercially available in a BioGlycol coolant formulation with an ethoxylated nonylphenol surfactant, and azole- and polyol-based non-ionic corrosion inhibitors. Exposure of a Pt/Vulcan carbon electrode to glycol-water or glycol-water-surfactant mixtures causes the loss of Pt electrochemical surface area (ECSA), but the Pt ECSA is fully recovered in clean electrolyte. Only mixtures with the azole corrosion inhibitor cause irreversible losses to the Pt ECSA and oxygen reduction reaction (ORR) activity. The Pt ECSA and ORR activity can only be recovered to within 70% of its initial values after aggressive voltammetric cycling to 1.50 V after azole poisoning. When poisoned with a glycol mixture containing the polyol corrosion inhibitor instead, the Pt ECSA and ORR activity is completely recovered by exposure to a clean electrolyte. The results suggest that prior to incorporation in a fuel cell, voltammetric evaluation of the constituents of coolant formulations is worthwhile.

  3. An Improved Design for Air Removal from Aerospace Fluid Loop Coolant Systems

    NASA Technical Reports Server (NTRS)

    Ritchie, Stephen M. C.; Holladay, Jon B.; Holt, J. Mike; Clark, Dallas W.

    2003-01-01

    Aerospace applications with requirements for large capacity heat removal (launch vehicles, platforms, payloads, etc.) typically utilize a liquid coolant fluid as a transport media to increase efficiency and flexibility in the vehicle design. An issue with these systems however, is susceptibility to the presence of noncondensable gas (NCG) or air. The presence of air in a coolant loop can have numerous negative consequences, including loss of centrifugal pump prime, interference with sensor readings, inhibition of heat transfer, and coolant blockage to remote systems. Hardware ground processing to remove this air is also cumbersome and time consuming which continuously drives recurring costs. Current systems for maintaining the system free of air are tailored and have demonstrated only moderate success. An obvious solution to these problems is the development and advancement of a passive gas removal device, or gas trap, that would be installed in the flight cooling system simplifying the initial coolant fill procedure and also maintaining the system during operations. The proposed device would utilize commercially available membranes thus increasing reliability and reducing cost while also addressing both current and anticipated applications. In addition, it maintains current pressure drop, water loss, and size restrictions while increasing tolerance for pressure increases due to gas build-up in the trap.

  4. Analysis of Loss-of-Coolant Accidents in the NBSR

    SciTech Connect

    Baek J. S.; Cheng L.; Diamond, D.

    2014-05-23

    This report documents calculations of the fuel cladding temperature during loss-of-coolant accidents in the NBSR. The probability of a pipe failure is small and procedures exist to minimize the loss of water and assure emergency cooling water flows into the reactor core during such an event. Analysis in the past has shown that the emergency cooling water would provide adequate cooling if the water filled the flow channels within the fuel elements. The present analysis is to determine if there is adequate cooling if the water drains from the flow channels. Based on photographs of how the emergency water flows into the fuel elements from the distribution pan, it can be assumed that this water does not distribute uniformly across the flow channels but rather results in a liquid film flowing downward on the inside of one of the side plates in each fuel element and only wets the edges of the fuel plates. An analysis of guillotine breaks shows the cladding temperature remains below the blister temperature in fuel plates in the upper section of the fuel element. In the lower section, the fuel plates are also cooled by water outside the element that is present due to the hold-up pan and temperatures are lower than in the upper section. For small breaks, the simulation results show that the fuel elements are always cooled on the outside even in the upper section and the cladding temperature cannot be higher than the blister temperature. The above results are predicated on assumptions that are examined in the study to see their influence on fuel temperature.

  5. Investigation of heat transfer in zirconium potassium perchlorate at low temperature: A study of the failure mechanism of the NASA standard initiator

    NASA Technical Reports Server (NTRS)

    Varghese, Philip L.

    1989-01-01

    The objective of this work was to study the reasons for the failure of pyrotechnic initiators at very low temperatures (10 to 100 K). A two-dimensional model of the NASA standard initiator was constructed to model heat transfer from the electrically heated stainless steel bridgewire to the zirconium potassium perchlorate explosive charge and the alumina charge cup. Temperature dependent properties were used in the model to simulate initiator performance over a wide range of initial temperatures (10 to 500 K). A search of the thermophysical property data base showed that pure alumina has a very high thermal conductivity at low temperatures. It had been assumed to act as a thermal insulator in all previous analyses. Rapid heat transfer from the bridgewire to the alumina at low initial temperatures was shown to cause failure of the initiators if the wire did not also make good contact with the zirconium potassium perchlorate charge. The mode is able to reproduce the results of the tests that had been conducted to investigate the cause for failure. It also provides an explanation for previously puzzling results and suggests simple design changes that will increase reliability at very low initial temperatures.

  6. Performance of the Extravehicular Mobility Unit (EMU) Airlock Coolant Loop Remediation (A/L CLR) Hardware - Final

    NASA Technical Reports Server (NTRS)

    Steele, John W.; Rector, Tony; Gazda, Daniel; Lewis, John

    2011-01-01

    An EMU water processing kit (Airlock Coolant Loop Recovery -- A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. A conservative duty cycle and set of use parameters for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. Several initiatives were undertaken to optimize the duty cycle and use parameters of the hardware. Examination of post-flight samples and EMU Coolant Loop hardware provided invaluable information on the performance of the A/L CLR and has allowed for an optimization of the process. The intent of this paper is to detail the evolution of the A/L CLR hardware, efforts to optimize the duty cycle and use parameters, and the final recommendations for implementation in the post-Shuttle retirement era.

  7. Three-dimensional turbulent-mixing-length modeling for discrete-hole coolant injection into a crossflow

    NASA Technical Reports Server (NTRS)

    Wang, C. R.; Papell, S. S.

    1983-01-01

    Three dimensional mixing length models of a flow field immediately downstream of coolant injection through a discrete circular hole at a 30 deg angle into a crossflow were derived from the measurements of turbulence intensity. To verify their effectiveness, the models were used to estimate the anisotropic turbulent effects in a simplified theoretical and numerical analysis to compute the velocity and temperature fields. With small coolant injection mass flow rate and constant surface temperature, numerical results of the local crossflow streamwise velocity component and surface heat transfer rate are consistent with the velocity measurement and the surface film cooling effectiveness distributions reported in previous studies.

  8. Loss-of-coolant accident experiment at the AVR gas-cooled reactor

    SciTech Connect

    Krueger, K. ); Cleveland, J. )

    1990-01-01

    A landmark safety test has been conducted at the AVR-reactor, a high-temperature gas-cooled reactor (HTGR) in the Federal Republic of Germany owned by the Arbeitsgemeinschaft Versuchsreaktor, AVR in Juelich. The 46-MW(t), 15-MW(e) AVR reactor was subjected to a simulated loss-of-coolant accident (LOCA), a very severe occurrence in which the coolant escapes from the reactor core and no emergency system provides coolant flow to the core. The test, which demonstrated the inherently safe response of this reactor to a LOCA, marked the first time ever that a reactor has been intentionally subjected to loss-of-coolant conditions without emergency cooling. Oak Ridge National Laboratory (ORNL) and General Atomics participated in the test by working with AVR staff by jointly performing the analyses needed to obtain the license to conduct the test and by performing post test analyses. This participation was carried out under the cooperative AVR Subprogram which is conducted within the US/FRG Agreement for Cooperation in Gas-Cooled Reactor Development. 7 figs.

  9. Desensitization of over tip leakage in an axial turbine rotor by tip surface coolant injection

    NASA Astrophysics Data System (ADS)

    Rao, Nikhil Molahally

    Mechanical energy extraction in axial flow turbine rotors occurs through a change in angular momentum of the working fluid. The gap between the turbine rotor and the stationary casing is referred to as the tip gap. High pressure turbine blades are typically un-shrouded and pressure driven flow through the tip gap is termed as over tip leakage. Over tip leakage reduces efficiency of the turbine stage and also causes thermal distress to blade tip surfaces. The gap height typically increases over the operational life of a turbine, leading to increased efficiency drop. The thermal load on the tip surface also increases with increasing gap height and is exacerbated by the radial transport of high temperature fluid found in the core of the combustor exit flow. Thus over tip leakage not only decreases stage efficiency, but also constrains it by limiting the maximum cycle temperature. Reducing the sensitivity of turbine performance to the effects of the tip gap is termed Tip Desensitization. An experimental investigation of tip desensitization through coolant injection from a tip surface trench was conducted in a large scale, low speed, rotating research turbine facility. Five out of twenty nine rotor blades, referred to as cooled blades, are provided with coolant injection at four locations, at 61%, 71%, 81%, and 91% blade tip axial chord length. At each of the first three locations the coolant jets are directed towards the blade pressure-side, while coolant is exhausted radially at the last location. The sensitivity of total pressure defect, due to over tip leakage, to tip gap height is reduced by both coolant injection and roughening of the casing surface. The total pressure defect due to the large gap height of 1.40% blade height is reduced to levels comparable to the defect due to a gap height of 0.72% blade height. The strong total pressure gradient that characterizes the leakage vortex due to the gap height of 1.40% blade height is considerably diminished by both

  10. An analytical study of the effect of coolant flow variables on the kinetic energy output of a cooled turbine blade flow

    NASA Technical Reports Server (NTRS)

    Prust, H. W., Jr.

    1971-01-01

    The results of an analytical study to determine the effect of changes in the amount, velocity, injection location, injection angle, and temperature of coolant flow on blade row performance are presented. The results show that the change in output of a cooled turbine blade row relative to the specific output of the uncooled blade row can be positive, negative, or zero. Comparisons between the analytical results and experimental results for four different cases of coolant discharge, all at a coolant temperature ratio of unity, show good agreement for three cases and rather poor agreement for the other. To further test the validity of the method, more experimental data is needed, particularly at different coolant temperature ratios.

  11. Parametric study on maximum transportable distance and cost for thermal energy transportation using various coolants

    SciTech Connect

    Su-Jong Yoon; Piyush Sabharwall

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.

  12. Preparation, conduct, and experimental results of the AVR loss-of-coolant accident simulation test

    SciTech Connect

    Kruger, K.; Bergerfurth, A.; Burger, S.; Pohl, P.; Wimmers, M. ); Cleveland, J.C. )

    1991-02-01

    A loss-of-coolant accident (LOCA) is one of the most severe accidents for a nuclear power plant. To demonstrate inherent safety characteristics incorporated into small high-temperature gas-cooled reactor (HTGR) design, LOCA simulation tests have been conducted at the Arbeitsgemeinschaft Versuchsreaktor (AVR), the German pebble-bed-high-temperature reactor plant. The AVR is the only nuclear power plant ever to have been intentionally subjected to LOCA conditions without emergency cooling. This paper presents the planning and licensing activities including pretest predictions performed for the LOCA test are described, and the conduct of the test and experimental results. The LOCA test was planned to create conditions that would exist if a rapid LOCA occurred with the reactor operating at full power. The test demonstrated this reactor's safe response to an accident in which the coolant escapes from the reactor core and no emergency system is available to provide coolant flow to the core. The test is of special interest because it demonstrates the inherent safety features incorporated into optimized modular HTGR designs. The main LOCA test lasted for 5 days. After the test began, core temperatures increased for {approx}13 h and then gradually and continually decreased as the rate of heat dissipation from the core exceeded the simulated decay power. Throughout the test, temperatures remained below limiting values for the core and other reactor components.

  13. Assessment of Thermal and Hydrodynamic Fragmentation in Molten Fuel Coolant Interaction With Simulant System

    SciTech Connect

    Narayanan, K.S.; Das, S.K.; Jasmin Sudha, A.; Rao, E.H.V.M.; Lydia, G.; Murthy, S.S.; Kumareshan, M.; Harvey, J.; Kasinathan, N.; Rajan, M.

    2006-07-01

    In the Safety analysis of Fast Breeder Reactor, assessment of Molten Fuel Coolant Interaction (MFCI) assumes importance for two aspects, namely the characterization of the debris and severity of pressure pulses generation. An attempt has been made to investigate the debris generation characteristics with molten Woods Metal (Alloy of Bi 50% Pb 25% Sn 12.5% and Cd 12.5% and melting point of 346 K) - Water simulant system. Liquid Woods metal and liquid Uranium dioxide physical properties (Density, Surface tension and Kinematic viscosity) are similar. Experimental studies were conducted for various melt temperatures covering non - boiling, convective boiling and film boiling regimes of water, to assess the debris generation resulting from both hydrodynamic and thermal interaction. Woods metal was heated to the desired temperature and poured through a hot funnel having a nozzle of 8 mm release diameter into a water column of height up to 140 cm. Experiments were repeated for different coolant temperature and melt inventory up to 5 kg. The melt entry velocity was determined from video recordings. The debris is analyzed on the basis of interface temperature, Rayleigh-Taylor and Kelvin - Helmholtz instabilities. It is observed that Kelvin-Helmholtz instability is the dominant fragmentation phenomena. Contribution due to coolant boiling resulted in more debris generation in the size less than 4 mm. (authors)

  14. Testing of organic acids in engine coolants

    SciTech Connect

    Weir, T.W.

    1999-08-01

    The effectiveness of 30 organic acids as inhibitors in engine coolants is reported. Tests include glassware corrosion of coupled and uncoupled metals. FORD galvanostatic and cyclic polarization electrochemistry for aluminum pitting, and reserve alkalinity (RA) measurements. Details of each test are discussed as well as some general conclusions. For example, benzoic acid inhibits coupled metals well but is ineffective on cast iron when uncoupled. In benzoic acid inhibits coupled metals well but is ineffective on cast iron when uncoupled. In general, the organic acids provide little RA when titrated to a pH of 5.5, titration to a pH of 4.5 can result in precipitation of the acid. Trends with respect to acid chain length are reported also.

  15. Power module assemblies with staggered coolant channels

    DOEpatents

    Herron, Nicholas Hayden; Mann, Brooks S; Korich, Mark D

    2013-07-16

    A manifold is provided for supporting a power module assembly with a plurality of power modules. The manifold includes a first manifold section. The first face of the first manifold section is configured to receive the first power module, and the second face of the first manifold section defines a first cavity with a first baseplate thermally coupled to the first power module. The first face of the second manifold section is configured to receive the second power module, and the second face of the second manifold section defines a second cavity with a second baseplate thermally coupled to the second power module. The second face of the first manifold section and the second face of the second manifold section are coupled together such that the first cavity and the second cavity form a coolant channel. The first cavity is at least partially staggered with respect to second cavity.

  16. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    DOE PAGESBeta

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; et al

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperaturemore » over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.« less

  17. High pressure coolant effect on PVD coated inserts during end milling of Ti-6AL-4V

    NASA Astrophysics Data System (ADS)

    Sridharan, Arvind

    Titanium alloys are being employed extensively in engineering and aerospace applications for their high strength to weight ratio, mechanical strength and ability to withstand high temperatures. Out of the different alloys of titanium available, the most commonly used alloy is Ti-6Al-4V. It is also called `Grade-5 titanium alloy' or 'α+β titanium alloy'. High speed machining of titanium alloys generates high temperatures in the cutting zone, promoting accelerated tool wear and reducing the efficiency in metal cutting. Consequently, the ability of the coolant to remove heat from the cutting zone plays an increasingly important role in the economics of the process as well as on the life of tool inserts. With the introduction of thru-tool coolant delivery, the coolant can now be delivered directly at the point of machining without having to flood the area of machining. This research tries to address the effects that high pressure and thru-tool coolant has on insert wear while end milling Ti-6Al-4V. The parameters used in this study are speed, feed, axial depth of cut, radial depth of cut and coolant pressure. A structured design of experiments along with a central composite design approach is used to determine the main effects of coolant pressure and its interactions with the remaining parameters. The results show that, within the parameters of this experiment, coolant pressure was not a significant main effect. However, pressure seems to react positively with feed rate. Contributions from this research can be used to recommend settings of the cutting factors in order to obtain the minimal tool wear.

  18. 73. View of line of stainless steel coolant storage tanks ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. View of line of stainless steel coolant storage tanks for bi-sodium sulfate/water coolant solution at first floor of transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  19. Effects of rotation on coolant passage heat transfer. Volume 1: Coolant passages with smooth walls

    NASA Technical Reports Server (NTRS)

    Hajek, T. J.; Wagner, J. H.; Johnson, B. V.; Higgins, A. W.; Steuber, G. D.

    1991-01-01

    An experimental program was conducted to investigate heat transfer and pressure loss characteristics of rotating multipass passages, for configurations and dimensions typical of modern turbine blades. The immediate objective was the generation of a data base of heat transfer and pressure loss data required to develop heat transfer correlations and to assess computational fluid dynamic techniques for rotating coolant passages. Experiments were conducted in a smooth wall large scale heat transfer model.

  20. Test plan for high-burnup fuel cladding behavior under loss-of- coolant accident conditions

    SciTech Connect

    Chung, H.M.; Neimark, L.A.; Kassner, T.F.

    1996-10-01

    Excessive oxidation, hydriding, and extensive irradiation damage occur in high-burnup fuel cladding, and as result, mechanical properties of high-burnup fuels are degraded significantly. This may influence the current fuel cladding failure limits for loss-of- coolant-accident (LOCA) situations, which are based on fuel cladding behavior for zero burnup. To avoid cladding fragmentation and fuel dispersal during a LOCA, 10 CFR 50.46 requires that peak cladding temperature shall not exceed 1204 degrees C (2200 degrees F) and that total oxidation of the fuel cladding nowhere exceeds 0.17 times total cladding thickness before oxidation. Because of the concern, a new experimental program to investigate high-burnup fuel cladding behavior under LOCA situations has been initiated under the sponsorship of the U.S. Nuclear Regulatory Commission. A hot-cell test plan to investigate single-rod behavior under simulated LOCA conditions is described in this paper. In the meantime, industry fuel design and operating conditions are expected to undergo further changes as more advanced cladding materials are developed. Under these circumstances, mechanical properties of high-burnup fuel cladding require further investigation so that results from studies on LOCA, reactivity- initiated-accident (RIA), operational transient, and power-ramping situations, can be extrapolated to modified or advanced cladding materials and altered irradiation conditions without repeating major integral experiments in test reactors. To provide the applicable data base and mechanistic understanding, tests will be conducted to determine dynamic and static fracture toughness and tensile properties. Background and rationale for selecting the specific mechanical properties tests are also described.

  1. The heat transfer characteristic of the reactor coolant pump canned motor

    NASA Astrophysics Data System (ADS)

    Gu, X. Y.; Xu, R.; Tao, G.; Yang, Y. L.; Wang, D. Z.

    2016-05-01

    This paper deals with the heat transfer characteristic of the reactor coolant pump canned motor. The cooling of the canned motor is an important issue for the design of the pump. In order to analyze the heat transfer characteristic of the canned motor, firstly the electromagnetic field of the canned motor is calculated with finite element method, and the magnetic resistance loss is gotten, then the heat distribution of the canned motor is obtained based on the electromagnetic field, finally the flow field and temperature field of the canned motor is calculated with CFD methods. The calculation indicates that the highest temperature and highest temperature rising are both occurred at the end winding.

  2. Numerical model of the hydrodynamics of the Black Sea and the Sea of Azov with variational initialization of temperature and salinity

    NASA Astrophysics Data System (ADS)

    Zalesny, V. B.; Gusev, A. V.; Moshonkin, S. N.

    2013-11-01

    A numerical primitive-equation model of the hydrodynamics of the Black Sea and the Sea of Azov in σ-coordinates is proposed. The model has a resolution of ˜4 × 4 km in horizontal coordinates with 40-σ levels in the vertical and includes the four-dimensional variational initialization of temperature and salinity fields. A numerical initialization algorithm combines splitting methods and adjoint equations. Flow, temperature, sea level, and salinity fields driven by atmospheric forcing are calculated for the year 2008. The calculations are made in a variational initialization — prediction regime. Temperature and salinity fields are initialized at the end of each month. The optimality system includes forward and adjoint transport-diffusion equations for heat and salt that are linearized on the assimilation interval. Results of three numerical experiments with different sets of assimilated data in comparison with the prediction obtained from the forward model are discussed.

  3. Lead Coolant Test Facility Technical and Functional Requirements, Conceptual Design, Cost and Construction Schedule

    SciTech Connect

    Soli T. Khericha

    2006-09-01

    This report presents preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic. Based on review of current world lead or lead-bismuth test facilities and research need listed in the Generation IV Roadmap, five broad areas of requirements of basis are identified: Develop and Demonstrate Prototype Lead/Lead-Bismuth Liquid Metal Flow Loop Develop and Demonstrate Feasibility of Submerged Heat Exchanger Develop and Demonstrate Open-lattice Flow in Electrically Heated Core Develop and Demonstrate Chemistry Control Demonstrate Safe Operation and Provision for Future Testing. These five broad areas are divided into twenty-one (21) specific requirements ranging from coolant temperature to design lifetime. An overview of project engineering requirements, design requirements, QA and environmental requirements are also presented. The purpose of this T&FRs is to focus the lead fast reactor community domestically on the requirements for the next unique state of the art test facility. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 420oC. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M. It is also estimated that the facility will require two years to be constructed and ready for operation.

  4. ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project

    NASA Technical Reports Server (NTRS)

    Morrison, Russell H.; Holt, Mike

    2005-01-01

    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate buffer concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. The remediation steps include changes in the coolant chemistry specification, development of a suite of new antimicrobial additives, and development of devices for the removal of nickel and phosphate ions from the coolant. This paper presents an overview of the anomalies, their known and suspected system effects, their causes, and the actions being taken to remediate the coolant.

  5. Reclamation and disposal of water-based machining coolants

    SciTech Connect

    Taylor, P.A.

    1982-01-01

    The Oak Ridge Y-12 Plant, which is operated by the Union Carbide Corporation, Nuclear Division for the Department of Energy under US government contract W-7405-eng-26, currently uses about 10{sup 6} L/yr (260,000 gal/yr) of water-based coolants in its machining operations. These coolants are disposed of in a 110,000-L (29,000-gal) activated sludge reactor. The reactor has oxidized an average of 38.6 kg of total organic carbon (TOC) per day with an overall efficiency of 90%. The predominant bacteria in the reactor have been identified once each year for the past three years. Six primary types of water-based coolants are currently used in the machine shops. In order to reduce the coolant usage rate, efforts are being made to introduce one universal coolant into the shops. By using a biocide to limit bacterial deterioration and using a filter and centrifuge system to remove dirt and tramp oils from the coolant, the coolant discard rate can be greatly reduced. 1 tab.

  6. Estimating Loss-of-Coolant Accident Frequencies for the Standardized Plant Analysis Risk Models

    SciTech Connect

    S. A. Eide; D. M. Rasmuson; C. L. Atwood

    2008-09-01

    The U.S. Nuclear Regulatory Commission maintains a set of risk models covering the U.S. commercial nuclear power plants. These standardized plant analysis risk (SPAR) models include several loss-of-coolant accident (LOCA) initiating events such as small (SLOCA), medium (MLOCA), and large (LLOCA). All of these events involve a loss of coolant inventory from the reactor coolant system. In order to maintain a level of consistency across these models, initiating event frequencies generally are based on plant-type average performance, where the plant types are boiling water reactors and pressurized water reactors. For certain risk analyses, these plant-type initiating event frequencies may be replaced by plant-specific estimates. Frequencies for SPAR LOCA initiating events previously were based on results presented in NUREG/CR-5750, but the newest models use results documented in NUREG/CR-6928. The estimates in NUREG/CR-6928 are based on historical data from the initiating events database for pressurized water reactor SLOCA or an interpretation of results presented in the draft version of NUREG-1829. The information in NUREG-1829 can be used several ways, resulting in different estimates for the various LOCA frequencies. Various ways NUREG-1829 information can be used to estimate LOCA frequencies were investigated and this paper presents two methods for the SPAR model standard inputs, which differ from the method used in NUREG/CR-6928. In addition, results obtained from NUREG-1829 are compared with actual operating experience as contained in the initiating events database.

  7. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D.; Turknett, Jerry C.; Smith, Alvin

    1989-01-01

    The effects of enhancement devices on flow boiling heat transfer in circular coolant channels, which are heated over a fraction of their perimeters, are studied. The variations were examined in both the mean and local (axial, and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls. Improvements were initiated in the present data reduction analysis. These efforts should lead to the development of heat transfer correlations which include effects of single side heat flux and enhancement device configuration. It is hoped that a stage will be set for the study of heat transfer and pressure drop in single sided heated systems under zero gravity conditions.

  8. Reactor coolant pump monitoring and diagnostic system

    SciTech Connect

    Singer, R.M.; Gross, K.C.; Walsh, M. ); Humenik, K.E. )

    1990-01-01

    In order to reliably and safely operate a nuclear power plant, it is necessary to continuously monitor the performance of numerous subsystems to confirm that the plant state is within its prescribed limits. An important function of a properly designed monitoring system is the detection of incipient faults in all subsystems (with the avoidance of false alarms) coupled with an information system that provides the operators with fault diagnosis, prognosis of fault progression and recommended (either automatic or prescriptive) corrective action. In this paper, such a system is described that has been applied to reactor coolant pumps. This system includes a sensitive pattern-recognition technique based upon the sequential probability ratio test (SPRT) that detects incipient faults from validated signals, an expert system embodying knowledge bases on pump and sensor performance, extensive hypertext files containing operating and emergency procedures as well as pump and sensor information and a graphical interface providing the operator with easily perceived information on the location and character of the fault as well as recommended corrective action. This system is in the prototype stage and is currently being validated utilizing data from a liquid-metal cooled fast reactor (EBR-II). 3 refs., 4 figs.

  9. Corrosion problems with aqueous coolants, final report

    SciTech Connect

    Diegle, R B; Beavers, J A; Clifford, J E

    1980-04-11

    The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

  10. The development of Sn-Li coolant/breeding material for APEX/ALPS applications.

    SciTech Connect

    Sze, D.-K.

    1999-07-08

    A Sn-Li alloy has been identified to be a coolant/breeding material for D-T fusion applications. The key feature of this material is its very low vapor pressure, which will be very useful for free surface concepts employed in APEX, ALPS and inertial confinement fission. The vapor is dominated by lithium, which has very low Z. Initial assessment of the material indicates acceptable tritium breeding capability, high thermal conductivity, expected low tritium volubility, and expected low chemical reactivities with water and air. Some key concerns are the high activation and material compatibility issues. The initial assessment of this material, for fission applications, is presented in this paper.

  11. Longer life for glyco-based stationary engine coolants

    SciTech Connect

    Hohlfeld, R.

    1996-07-01

    Large, stationary diesel engines used to compress natural gas that is to be transported down pipelines generate a great deal of heat. Unless this heat is dissipated efficiently, it will eventually cause an expensive breakdown. Whether the coolant uses ethylene glycol or propylene glycol, the two major causes of glycol degradation are heat and oxidation. The paper discusses inhibitors that enhance coolant service life and presents a comprehensive list of do`s and don`ts for users to gain a 20-year coolant life.

  12. Turbomachine injection nozzle including a coolant delivery system

    DOEpatents

    Zuo, Baifang

    2012-02-14

    An injection nozzle for a turbomachine includes a main body having a first end portion that extends to a second end portion defining an exterior wall having an outer surface. A plurality of fluid delivery tubes extend through the main body. Each of the plurality of fluid delivery tubes includes a first fluid inlet for receiving a first fluid, a second fluid inlet for receiving a second fluid and an outlet. The injection nozzle further includes a coolant delivery system arranged within the main body. The coolant delivery system guides a coolant along at least one of a portion of the exterior wall and around the plurality of fluid delivery tubes.

  13. Modeling Reactor Coolant Systems Thermal-Hydraulic Transients

    Energy Science and Technology Software Center (ESTSC)

    1999-10-05

    RELAP5/MOD3.2* is used to model reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents and operational transients such as anticipated transients without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits simulating a variety of thermal-hydraulic systems. Control system and secondary system components are included to allow modeling of themore » plant controls, turbines, condensers, and secondary feedwater systems.« less

  14. The impact of radiolytic yield on the calculated ECP in PWR primary coolant circuits

    NASA Astrophysics Data System (ADS)

    Urquidi-Macdonald, Mirna; Pitt, Jonathan; Macdonald, Digby D.

    2007-05-01

    A code, PWR-ECP, comprising chemistry, radiolysis, and mixed potential models has been developed to calculate radiolytic species concentrations and the corrosion potential of structural components at closely spaced points around the primary coolant circuits of pressurized water reactors (PWRs). The pH( T) of the coolant is calculated at each point of the primary-loop using a chemistry model for the B(OH) 3 + LiOH system. Although the chemistry/radiolysis/mixed potential code has the ability to calculate the transient reactor response, only the reactor steady state condition (normal operation) is discussed in this paper. The radiolysis model is a modified version of the code previously developed by Macdonald and coworkers to model the radiochemistry and corrosion properties of boiling water reactor primary coolant circuits. In the present work, the PWR-ECP code is used to explore the sensitivity of the calculated electrochemical corrosion potential (ECP) to the set of radiolytic yield data adopted; in this case, one set had been developed from ambient temperature experiments and another set reported elevated temperatures data. The calculations show that the calculated ECP is sensitive to the adopted values for the radiolytic yields.

  15. Modeling Cladding-Coolant Heat Transfer of High-Burnup Fuel During RIA

    SciTech Connect

    Wenfeng Liu; Kazimi, Mujid S.

    2006-07-01

    This paper describes a model for the cladding-coolant heat transfer of high burnup fuel during a Reactivity Initiated Accident (RIA) which is implemented in the fuel performance code FRAPTRAN 1.2. The minimum stable film boiling temperature, affected by the subcooling and the clad oxidation, is modeled by a modified Henry correlation. This accounts for the effects of thermal properties of the cladding surface on the transient temperature drop during liquid-solid contact. The transition boiling regime is described as the interpolation of the heat flux between two anchor points on the boiling curve: the Critical Heat Flux (CHF) and minimum stable film boiling. The CHF correlation is based on the Zuber hydrodynamic model multiplied by a subcooling factor. Frederking correlation is chosen to model the film boiling regime. The heat conduction through the oxide layer of the cladding surface of high burnup fuel is calculated by solving heat conduction equations with thermal properties of zirconia taken from MATPRO. This model is validated in the FRAPTRAN code for test cases of both high burnup and fresh test fuel rods including the burnup level (0--56 MW d/kg), peak fuel enthalpy deposit (70--190 cal/g), degree of subcooling (0--80 deg. C), and extent of oxidation (0--25 micron). The modified code demonstrates the capability of differentiating between the departure from nucleate boiling (DNB) and none-DNB cases. The predicted peak cladding temperature (PCT) and duration of DNB achieves generally good agreement with the experimental data. It is found that the cladding surface oxidation of high burnup fuel causes an early rewetting of cladding or suppresses DNB due to two factors: 1) Thick zirconia layer may delay the heat conducted to the surface while keeping the surface heat transfer in the most effective nucleate boiling regime. 2) The transient liquid-solid contact resulting from vapor breaking down would cause a lower interface temperature for an oxidized surface

  16. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D.

    1991-01-01

    Future space exploration and commercialization will require more efficient heat rejection systems. For the required heat transfer rates, such systems must use advanced heat transfer techniques. Forced two phase flow boiling heat transfer with enhancements falls in this category. However, moderate to high quality two phase systems tend to require higher pressure losses. This report is divided into two major parts: (1) Multidimensional wall temperature measurement and heat transfer enhancement for top heated horizontal channels with flow boiling; and (2) Improved analytical heat transfer data reduction for a single side heated coolant channel. Part 1 summarizes over forty experiments which involve both single phase convection and flow boiling in a horizontal channel heated externally from the top side. Part 2 contains parametric dimensionless curves with parameters such as the coolant channel radius ratio, the Biot number, and the circumferential coordinate.

  17. Copper-based micro-channel cooler reliably operated using solutions of distilled-water and ethanol as a coolant

    NASA Astrophysics Data System (ADS)

    Chin, A. K.; Nelson, A.; Chin, R. H.; Bertaska, R.; Jacob, J. H.

    2015-03-01

    Copper-based micro-channel coolers (Cu-MCC) are the lowest thermal-resistance heat-sinks for high-power laserdiode (LD) bars. Presently, the resistivity, pH and oxygen content of the de-ionized water coolant, must be actively controlled to minimize cooler failure by corrosion and electro-corrosion. Additionally, the water must be constantly exposed to ultraviolet radiation to limit the growth of micro-organisms that may clog the micro-channels. In this study, we report the reliable, care-free operation of LD-bars attached to Cu-MCCs, using a solution of distilledwater and ethanol as the coolant. This coolant meets the storage requirements of Mil-Std 810G, e.g. exposure to a storage temperature as low as -51°C and no growth of micro-organisms during passive storage.

  18. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    SciTech Connect

    Siamidis, John; Mason, Lee

    2006-01-20

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS{sub O}pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  19. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    NASA Technical Reports Server (NTRS)

    Siamidis, John; Mason, Lee S.

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  20. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Siamidis, John

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H20 for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  1. Tables of thermodynamic properties of helium magnet coolant. Revision A

    SciTech Connect

    McAshan, M.

    1992-07-01

    The most complete treatment of the thermodynamic properties of helium at the present time is the monograph by McCarty: ``Thermodynamic Properties of Helium 4 from 2 to 1500 K at Pressures to 10{sup 8} Pa``, Robert D. McCarty, Journal of Physical and Chemical Reference Data, Vol. 2, page 923--1040 (1973). In this work the complete range of data on helium is examined and the P-V-T surface is described by an equation of state consisting of three functions P(r,T) covering different regions together with rules for making the transition from one region to another. From this thermodynamic compilation together with correlations of the transport properties of helium was published the well-known NBS Technical Note: ``Thermophysical Properties of Helium 4 from 2 to 1500 K with pressures to 1000 Atmospheres``, Robert D. McCarty, US Department of Commerce, National Bureau of Standards Technical Note 631 (1972). This is the standard reference for helium cryogenics. The NBS 631 tables cover a wide range of temperature and pressure, and as a consequence, the number of points tabulated in the region of the single phase coolant for the SSC magnets are relatively few. The present work sets out to cover the range of interest in more detail in a way that is consistent with NBS 631. This new table is essentially identical to the older one and can be used as an auxiliary to it.

  2. Tables of thermodynamic properties of helium magnet coolant

    SciTech Connect

    McAshan, M.

    1992-07-01

    The most complete treatment of the thermodynamic properties of helium at the present time is the monograph by McCarty: Thermodynamic Properties of Helium 4 from 2 to 1500 K at Pressures to 10{sup 8} Pa'', Robert D. McCarty, Journal of Physical and Chemical Reference Data, Vol. 2, page 923--1040 (1973). In this work the complete range of data on helium is examined and the P-V-T surface is described by an equation of state consisting of three functions P(r,T) covering different regions together with rules for making the transition from one region to another. From this thermodynamic compilation together with correlations of the transport properties of helium was published the well-known NBS Technical Note: Thermophysical Properties of Helium 4 from 2 to 1500 K with pressures to 1000 Atmospheres'', Robert D. McCarty, US Department of Commerce, National Bureau of Standards Technical Note 631 (1972). This is the standard reference for helium cryogenics. The NBS 631 tables cover a wide range of temperature and pressure, and as a consequence, the number of points tabulated in the region of the single phase coolant for the SSC magnets are relatively few. The present work sets out to cover the range of interest in more detail in a way that is consistent with NBS 631. This new table is essentially identical to the older one and can be used as an auxiliary to it.

  3. Tables of thermodynamic properties of helium magnet coolant, revision A

    NASA Astrophysics Data System (ADS)

    McAshan, M.

    1992-07-01

    The most complete treatment of the thermodynamic properties of helium at the present time is the monograph by McCarty: 'Thermodynamic Properties of Helium 4 from 2 to 1500 K at Pressures to 10(exp 8) Pa', Robert D. McCarty, Journal of Physical and Chemical Reference Data, Vol. 2, page 923-1040 (1973). In this work the complete range of data on helium is examined and the P-V-T surface is described by an equation of state consisting of three functions P(r,T) covering different regions together with rules for making the transition from one region to another. From this thermodynamic compilation together with correlations of the transport properties of helium was published the well-known NBS Technical Note: 'Thermophysical Properties of Helium 4 from 2 to 1500 K with pressures to 1000 Atmospheres', Robert D. McCarty, US Department of Commerce, National Bureau of Standards Technical Note 631 (1972). This is the standard reference for helium cryogenics. The NBS 631 tables cover a wide range of temperature and pressure, and as a consequence, the number of points tabulated in the region of the single phase coolant for the SSC magnets are relatively few. The present work sets out to cover the range of interest in more detail in a way that is consistent with NBS 631. This new table is essentially identical to the older one and can be used as an auxiliary to it.

  4. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive engine coolants at a New Jersey Department of Transportation garage. he specific recycling units evaluated are based on the technologies of filtration and distilla...

  5. Transient two-phase performance of LOFT reactor coolant pumps

    SciTech Connect

    Chen, T.H.; Modro, S.M.

    1983-01-01

    Performance characteristics of Loss-of-Fluid Test (LOFT) reactor coolant pumps under transient two-phase flow conditions were obtained based on the analysis of two large and small break loss-of-coolant experiments conducted at the LOFT facility. Emphasis is placed on the evaluation of the transient two-phase flow effects on the LOFT reactor coolant pump performance during the first quadrant operation. The measured pump characteristics are presented as functions of pump void fraction which was determined based on the measured density. The calculated pump characteristics such as pump head, torque (or hydraulic torque), and efficiency are also determined as functions of pump void fractions. The importance of accurate modeling of the reactor coolant pump performance under two-phase conditions is addressed. The analytical pump model, currently used in most reactor analysis codes to predict transient two-phase pump behavior, is assessed.

  6. INVESTIGATION OF CLEANER TECHNOLOGIES TO MINIMIZE AUTOMOTIVE COOLANT WASTES

    EPA Science Inventory

    The US Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction and econo...

  7. Effects of rotation on coolant passage heat transfer. Volume 2: Coolant passages with trips normal and skewed to the flow

    NASA Technical Reports Server (NTRS)

    Johnson, B. V.; Wagner, J. H.; Steuber, G. D.

    1993-01-01

    An experimental program was conducted to investigate heat transfer and pressure loss characteristics of rotating multipass passages, for configurations and dimensions typical of modem turbine blades. This experimental program is one part of the NASA Hot Section Technology (HOST) Initiative, which has as its overall objective the development and verification of improved analysis methods that will form the basis for a design system that will produce turbine components with improved durability. The objective of this program was the generation of a data base of heat transfer and pressure loss data required to develop heat transfer correlations and to assess computational fluid dynamic techniques for rotating coolant passages. The experimental work was broken down into two phases. Phase 1 consists of experiments conducted in a smooth wall large scale heat transfer model. A detailed discussion of these results was presented in volume 1 of a NASA Report. In Phase 2 the large scale model was modified to investigate the effects of skewed and normal passage turbulators. The results of Phase 2 along with comparison to Phase 1 is the subject of this Volume 2 NASA Report.

  8. Neutronic and Physical Characteristics of an Accelerator Driven System with a Lead-208 Coolant

    SciTech Connect

    Khorasanov, Georgy L.; Ivonov, Anatoly P.; Blokhin, Anatoly I.

    2006-07-01

    In the paper a possibility of using a lead isotope, pure Pb-208, as a coolant for a subcritical core of 80 MW thermal capacity of the PDS-XADS type facility is considered. Calculations of neutronic characteristics were performed using Monte Carlo technique. The following initial data were chosen: an annular core with a target, as a neutron source, at its centre; the core coolant -- Pb-208 (100%); a fuel -- a mix of mono nitrides of depleted uranium and power plutonium with a small share of neptunium and americium; the target coolant -- a modified lead and bismuth eutectic, Pb-208(80%)-Bi(20%); proton beam energy -- 600 MeV; effective multiplication factor of the core under operation -- K{sub eff} = 0.97; thermal capacity of the core -- N = 80 MW. From calculations performed it follows that in using Pb-208 as the core coolant the necessary intensity of the external source of neutrons to deliver 80 MW thermal capacity is equal to S = 2.29-10{sup 17} n/s that corresponds to proton beam current I{sub p} = 2.8 mA and beam capacity P{sub p} 1.68 MW. In using natural lead instead of Pb-208 as the core coolant, effective multiplication factor of the core in normal operating regime falls down to the value equal to K{sub eff} = 0.95. In these conditions multiplication of external neutrons in the core and thermal capacity of the subcritical core are below nominal by 1.55 times. For achievement the rated core power N=80 MW it is required on {approx}20-30% to increase the fuel loading and volume of the core, or by 1.55 times to increase intensity of the external source of neutrons. In the last case, the required parameters of the neutron source and of the corresponding proton beam are following: intensity of the neutron source S = 3.55 10{sup 17} n/s., beam current I{sub p} = 4.32 mA, beam capacity P{sub p} 2.59 MW. To exploit the accelerator with the reduced proton beam current it will be required about 56 tons of Pb-208, as a minimum, for the core coolant. Charges for its

  9. Optimized Coolant-Flow Diverter For Increased Bearing Life

    NASA Technical Reports Server (NTRS)

    Subbaraman, Maria R.; Butner, Myles F.

    1995-01-01

    Coolant-flow diverter for rolling-element bearings in cryogenic turbopump designed to enhance cooling power of flow in contact with bearings and thereby reduce bearing wear. Delivers jets of coolant as close as possible to hot spots at points of contact between balls and race. Also imparts swirl that enhances beneficial pumping effect. Used with success in end ball bearing of high-pressure-oxidizer turbopump.

  10. Hydrodynamics of large-scale fuel-coolant interactions. [LMFBR

    SciTech Connect

    Baines, M.; Board, S.J.; Buttery, N.E.

    1980-06-01

    The analogy between thermal reactive and chemical reactive flows suggests that all propagating thermal explosions have a detonation-like (i.e., shock) structure. A vapor detonation model, which allows for thermal disequilibrium in the coolant, is developed. It is suggested that similar nonequilibrium effects may limit the efficiency of UO/sub 2/-sodium system, however, because of high conductivity of the coolant. 34 refs.

  11. Investigation of cleaner technologies to minimize automotive coolant wastes

    SciTech Connect

    Randall, P.M.

    1993-01-01

    The U.S. Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction, and economic issues. In addition, the authors examined the potential for substituting propylene glycol for ethylene glycol based engine coolant formulations. (Copyright (c) 1993 Butterworth-Heinemann Ltd.)

  12. Comparison of Lead-Bismuth and Lead as Coolants for Accelerator Driven Systems

    SciTech Connect

    Bianchi, F.; Mattioda, F.; Meloni, P.

    2002-07-01

    In the framework of the Italian research program TRASCO (TRAsmutazione SCOrie, namely transmutation of radioactive wastes) and of the European research program PDS-XADS (Preliminary Design Study on an eXperimental Accelerator Driven System) the feasibility and operability of gas or liquid metal cooled accelerator driven system prototypes are currently under investigation. Initially the attention of the thermal-hydraulics group of ENEA research centre in Bologna has been focussed toward a lead-bismuth cooled subcritical system under natural or enhanced natural circulation according to the prototype design proposed. The interest in using lead as a coolant, which is characterized by a higher melting point, is explained by the need to increase the plant efficiency for the economic competitiveness, though the higher temperatures pose some technological problems. Moreover, the amount of activation products should result significantly lower. Of course the results obtained and the experience gained analysing the dynamical behaviour of the lead-bismuth cooled system cannot be directly transferred to lead cooled systems. This paper aims at presenting a preliminary comparison of lead-bismuth and lead in a simplified liquid metal cooled subcritical system, mainly from the thermal-hydraulics and system dynamics points of view. By means of the modified RELAP5 version, the dynamical behavior of a lead-bismuth or lead cooled system, which is intended to be a quite accurate representation of the Italian accelerator driven prototype XADS, has been studied. Although a more exhaustive comparison should take into account the necessarily different structural characteristics of lead-bismuth and lead cooled systems, the neutronic feedback on reactor power and also the slightly different neutronic properties of lead-bismuth and lead, the purely thermal-hydraulic analysis presented in this paper has shown that the dynamical behaviour of the XADS does not differ noticeable when lead is used

  13. Probabilistic assessment of decoupling loss-of-coolant accident and earthquake in nuclear power plant design

    SciTech Connect

    Lu, S.C.; Harris, D.O.

    1981-01-01

    This paper describes a research project conducted at Lawrence Livermore National Laboratory to establish a technical basis for reassessing the requirement of combining large loss-of-coolant-accident (LOCA) and earthquake loads in nuclear power plant design. A large LOCA is defined herein as a double-ended guillotine break of the primary reactor coolant loop piping (the hot leg, cold leg, and crossover) of a pressureized water reactor (PWR). A systematic probability approach has been employed to estimate the probability of a large LOCA directly and indirectly induced by earthquakes. The probability of a LOCA directly induced by earthquakes was assessed by a numerical simulation of pipe rupture of a reactor coolant system. The simulation employed a deterministic fracture mechanics model which dictates the fatigue growth of pre-existing cracks in the pipe. The simulation accounts for the stochastic nature of input elements such as the initial crack size distribution, the crack occurrence rate, crack and leak detection probabilities as functions of crack size, plant transient occurrence rates, the seismic hazard, stress histories, and crack growth model parameters. Effects on final results due to variation an uncertainty of input elements were assessed by a limited sensitivity study. Results of the simulation indicate that the probability of a double-ended guillotine break, either with or without an earthquake, is very small (on the orer of 10/sup -12/). The probability of a leak was found to be several orders of magnitudes greater than that of a complete break.

  14. Evaluation of SCC test methods for Inconel 600 in low temperature aqueous solutions

    SciTech Connect

    Newman, R.C.; Roberge, R.; Bandy, R.

    1982-04-01

    In late 1981, widespread leakage was encountered in Alloy 600 steam-generator tubing at the Three Mile Island Unit 1 nuclear power plant. The phenomenon was identified as low-temperature intergranular stress-corrosion cracking (SCC) initiated from the inner surfaces of the tubes exposed to the primary coolant. A testing program was initiated to examine the material and environmental factors relevant to these failures, which were found to be associated with sensitization of the material and contamination of the coolant by air and sodium thiosulfate. The test solutions contained 1.3% boric acid with various additions of sulfur compounds and lithium hydroxide. Constant extension rate testing was used as the primary tool to examine environmental effects such as the inhibition of cracking by lithium hydroxide. Important effects of crack-initiation frequency on the specimen potential (and therefore crack velocity) are demonstrated.

  15. Additional requirements for leak-before-break application to primary coolant piping in Belgium

    SciTech Connect

    Roussel, G.

    1997-04-01

    Leak-Before-Break (LBB) technology has not been applied in the first design of the seven Pressurized Water Reactors the Belgian utility is currently operating. The design basis of these plants required to consider the dynamic effects associated with the ruptures to be postulated in the high energy piping. The application of the LBB technology to the existing plants has been recently approved by the Belgian Safety Authorities but with a limitation to the primary coolant loop. LBB analysis has been initiated for the Doel 3 and Tihange 2 plants to allow the withdrawal of some of the reactor coolant pump snubbers at both plants and not reinstall some of the restraints after steam generator replacement at Doel 3. LBB analysis was also found beneficial to demonstrate the acceptability of the primary components and piping to the new conditions resulting from power uprating and stretch-out operation. LBB analysis has been subsequently performed on the primary coolant loop of the Tihange I plant and is currently being performed for the Doel 4 plant. Application of the LBB to the primary coolant loop is based in Belgium on the U.S. Nuclear Regulatory Commission requirements. However the Belgian Safety Authorities required some additional analyses and put some restrictions on the benefits of the LBB analysis to maintain the global safety of the plant at a sufficient level. This paper develops the main steps of the safety evaluation performed by the Belgian Safety Authorities for accepting the application of the LBB technology to existing plants and summarizes the requirements asked for in addition to the U.S. Nuclear Regulatory Commission rules.

  16. Assessment of fiber optic sensors for aging monitoring of industrial liquid coolants

    NASA Astrophysics Data System (ADS)

    Riziotis, Christos; El Sachat, Alexandros; Markos, Christos; Velanas, Pantelis; Meristoudi, Anastasia; Papadopoulos, Aggelos

    2015-03-01

    Lately the demand for in situ and real time monitoring of industrial assets and processes has been dramatically increased. Although numerous sensing techniques have been proposed, only a small fraction can operate efficiently under harsh industrial environments. In this work the operational properties of a proposed photonic based chemical sensing scheme, capable to monitor the ageing process and the quality characteristics of coolants and lubricants in industrial heavy machinery for metal finishing processes is presented. The full spectroscopic characterization of different coolant liquids revealed that the ageing process is connected closely to the acidity/ pH value of coolants, despite the fact that the ageing process is quite complicated, affected by a number of environmental parameters such as the temperature, humidity and development of hazardous biological content as for example fungi. Efficient and low cost optical fiber sensors based on pH sensitive thin overlayers, are proposed and employed for the ageing monitoring. Active sol-gel based materials produced with various pH indicators like cresol red, bromophenol blue and chorophenol red in tetraethylorthosilicate (TEOS), were used for the production of those thin film sensitive layers deposited on polymer's and silica's large core and highly multimoded optical fibers. The optical characteristics, sensing performance and environmental robustness of those optical sensors are presented, extracting useful conclusions towards their use in industrial applications.

  17. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D., Sr.; Smith, Alvin

    1990-01-01

    The use of flow boiling for thermal energy transport is intended to provide an alternative for accommodating higher heat fluxes in commercial space systems. The objectives are to: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls, spiral fins, or both spiral fins and a twisted tape; (2) examine the effects of channel diameter and subcooling; and (3) develop an improved reduction analysis and/or suggest possible heat transfer correlation of the present data. Freon-11 is the working fluid. Two-dimensional (circumferential and axial) wall temperature distributions were measured for coolant channels with the above noted internal geometries. The flow regimes which are being studied are: (1) single phase; (2) subcooled flow boiling; and (3) stratified flow boiling. The inside diameter of all test sections is near 1.0 cm. Cicumferentially averaged heat transfer coefficients at several axial locations were obtained for selected coolant channels for a mass velocity of 210 kg/sq m s, an exit pressure of 0.19 MPa (absolute), and an inlet subcooling of 20.8 C. Overall (averaged over the entire channel) heat transfer coefficients were compared for the above channel geometries. This comparison showed that the channel with large pitch spiral fins had higher heat transfer coefficients at all power levels.

  18. Effects of LWR coolant environments on fatigue design curves of carbon and low-alloy steels

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1998-03-01

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the code specify fatigue design curves for structural materials. While effects of reactor coolant environments are not explicitly addressed by the design curves, test data indicate that the Code fatigue curves may not always be adequate in coolant environments. This report summarizes work performed by Argonne National Laboratory on fatigue of carbon and low-alloy steels in light water reactor (LWR) environments. The existing fatigue S-N data have been evaluated to establish the effects of various material and loading variables such as steel type, dissolved oxygen level, strain range, strain rate, temperature, orientation, and sulfur content on the fatigue life of these steels. Statistical models have been developed for estimating the fatigue S-N curves as a function of material, loading, and environmental variables. The results have been used to estimate the probability of fatigue cracking of reactor components. The different methods for incorporating the effects of LWR coolant environments on the ASME Code fatigue design curves are presented.

  19. Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket

    DOEpatents

    Christiansen, D.W.; Schively, D.P.

    1982-01-19

    The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  20. Fuel, Structural Material and Coolant for an Advanced Fast Micro-Reactor

    NASA Astrophysics Data System (ADS)

    Do Nascimento, J. A.; Duimarães, L. N. F.; Ono, S.

    The use of nuclear reactors in space, seabed or other Earth hostile environment in the future is a vision that some Brazilian nuclear researchers share. Currently, the USA, a leader in space exploration, has as long-term objectives the establishment of a permanent Moon base and to launch a manned mission to Mars. A nuclear micro-reactor is the power source chosen to provide energy for life support, electricity for systems, in these missions. A strategy to develop an advanced micro-reactor technologies may consider the current fast reactor technologies as back-up and the development of advanced fuel, structural and coolant materials. The next generation reactors (GEN-IV) for terrestrial applications will operate with high output temperature to allow advanced conversion cycle, such as Brayton, and hydrogen production, among others. The development of an advanced fast micro-reactor may create a synergy between the GEN-IV and space reactor technologies. Considering a set of basic requirements and materials properties this paper discusses the choice of advanced fuel, structural and coolant materials for a fast micro-reactor. The chosen candidate materials are: nitride, oxide as back-up, for fuel, lead, tin and gallium for coolant, ferritic MA-ODS and Mo alloys for core structures. The next step will be the neutronic and burnup evaluation of core concepts with this set of materials.

  1. Sealing of a shrouded rotor-stator system with pre-swirl coolant

    NASA Astrophysics Data System (ADS)

    El-Oun, Z. B.; Neller, P. H.; Turner, A. B.

    1987-05-01

    Experimental results for a modeled gas turbine rotor-stator system using both preswirled blade coolant and radially outward flowing disc coolant are presented. Although the preswirled coolant flow is found to have little effect on the pressure distribution below the preswirl nozzles, it is shown that considerable contamination of the preswirled coolant by the frictionally heated disc coolant can occur. A clear pressure inversion effect was found when coolant was provided by the preswirl nozzles alone, while the pressure under the rim seal increased with increasing rotational speed. Blade coolant flow increases the sealing flow requirement, except at the lowest flow rates.

  2. Evaluation of prompt nucleation of bubbles in annular fuel elements during the initial depressurization transient of a DEGB LOCA

    SciTech Connect

    Smith, A.C.

    1997-06-01

    In the first moments following the pipe break, of a DEGB LOCA, the depressurization wave is postulated to propagate rapidly through the system, in the manner of an acoustic or water hammer wave. this is immediately followed by a (reflected) repressurization wave, as the flow of coolant through the break is established. The pressure history is then dictated by the flow from the break and the ability of the pressurizer, pumps and accumulators to supply coolant. The initial sudden drop in pressure may result in the system pressure falling below the saturation pressure of the coolant. This could, in turn, result in bubble formation. Such immediate vapor formation (prompt nucleation of bubbles), in the period before the repressurization wave restores the system pressure to a level above the saturation pressure might initiate flow instability. Such an interruption in flow would allow the fuel tube clad temperature to increase rapidly. Depending on the duration of the flow interruption, the reactor might not be able to survive the initial moments of DEGB LOCA. It has generally been that this phenomenon would not actually occur in an operating reactor. The purpose of this investigation is to evaluate the possibility of occurrence of bubble formation as a result of initial depressurization. 7 refs., 6 figs.

  3. Apparatus for controlling coolant level in a liquid-metal-cooled nuclear reactor

    DOEpatents

    Jones, Robert D.

    1978-01-01

    A liquid-metal-cooled fast-breeder reactor which has a thermal liner spaced inwardly of the pressure vessel and includes means for passing bypass coolant through the annulus between the thermal liner and the pressure vessel to insulate the pressure vessel from hot outlet coolant includes control ports in the thermal liner a short distance below the normal operating coolant level in the reactor and an overflow nozzle in the pressure vessel below the control ports connected to an overflow line including a portion at an elevation such that overflow coolant flow is established when the coolant level in the reactor is above the top of the coolant ports. When no makeup coolant is added, bypass flow is inwardly through the control ports and there is no overflow; when makeup coolant is being added, coolant flow through the overflow line will maintain the coolant level.

  4. Influence of coolant pH on corrosion of 6061 aluminum under reactor heat transfer conditions

    SciTech Connect

    Pawel, S.J.; Felde, D.K.; Pawel, R.E.

    1995-10-01

    To support the design of the Advanced Neutron Source (ANS), an experimental program was conducted wherein aluminum alloy specimens were exposed at high heat fluxes to high-velocity aqueous coolants in a corrosion test loop. The aluminum alloys selected for exposure were candidate fuel cladding materials, and the loop system was constructed to emulate the primary coolant system for the proposed ANS reactor. One major result of this program has been the generation of an experimental database defining oxide film growth on 6061 aluminum alloy cladding. Additionally, a data correlation was developed from the database to permit the prediction of film growth for any reasonable thermal-hydraulic excursion. This capability was utilized effectively during the conceptual design stages of the reactor. During the course of this research, it became clear that the kinetics of film growth on the aluminum alloy specimens were sensitively dependent on the chemistry of the aqueous coolant and that relatively small deviations from the intended pH 5 operational level resulted in unexpectedly large changes in the corrosion behavior. Examination of the kinetic influences and the details of the film morphology suggested that a mechanism involving mass transport from other parts of the test loop was involved. Such a mechanism would also be expected to be active in the operating reactor. This report emphasizes the results of experiments that best illustrate the influence of the nonthermal-hydraulic parameters on film growth and presents data to show that comparatively small variations in pH near 5.0 invoke a sensitive response. Simply, for operation in the temperature and heat flux range appropriate for the ANS studies, coolant pH levels from 4.5 to 4.9 produced significantly less film growth than those from pH 5.1 to 6. A mechanism for this behavior based on the concept of treating the entire loop as an active corrosion system is presented.

  5. Integrative effect of drought and low temperature on litchi (Litchi chinensis Sonn.) floral initiation revealed by dynamic genome-wide transcriptome analysis.

    PubMed

    Shen, Jiyuan; Xiao, Qiusheng; Qiu, Haiji; Chen, Chengjie; Chen, Houbin

    2016-01-01

    Floral induction in litchi is influenced by multiple environment cues including temperature and soil water condition. In the present study, we determined that a combined treatment consisting of 14-day drought imposed prior to exposure to 35-day low temperature (T3) significantly promoted litchi flowering relative to the low temperature alone (T2), suggesting an integrative effect of drought and low temperature on litchi floral initiation. Analysis of transcriptomic changes in leaves from different treatments showed that 2,198 and 4,407 unigenes were differentially expressed in response to drought and low temperature, respectively. 1,227 of these unigenes were expressed in response to both treatments, implying an interaction of drought and low temperature on expression of genes involved in litchi floral initiation. Additionally, 932 unigenes were consistently differentially expressed during floral induction between T2 and T3 plants, which potentially accounts for the difference of flowering time. Thirty-eight transcription factors out of these 932 unigenes were identified as hub genes with central roles in regulation of litchi floral induction. The expression of litchi homologs of well-known flowering genes was also investigated, and one Flowering Locus T (FT) homolog may play a crucial role in litchi flowering in responses to drought and low temperature. PMID:27557749

  6. Integrative effect of drought and low temperature on litchi (Litchi chinensis Sonn.) floral initiation revealed by dynamic genome-wide transcriptome analysis

    PubMed Central

    Shen, Jiyuan; Xiao, Qiusheng; Qiu, Haiji; Chen, Chengjie; Chen, Houbin

    2016-01-01

    Floral induction in litchi is influenced by multiple environment cues including temperature and soil water condition. In the present study, we determined that a combined treatment consisting of 14-day drought imposed prior to exposure to 35-day low temperature (T3) significantly promoted litchi flowering relative to the low temperature alone (T2), suggesting an integrative effect of drought and low temperature on litchi floral initiation. Analysis of transcriptomic changes in leaves from different treatments showed that 2,198 and 4,407 unigenes were differentially expressed in response to drought and low temperature, respectively. 1,227 of these unigenes were expressed in response to both treatments, implying an interaction of drought and low temperature on expression of genes involved in litchi floral initiation. Additionally, 932 unigenes were consistently differentially expressed during floral induction between T2 and T3 plants, which potentially accounts for the difference of flowering time. Thirty-eight transcription factors out of these 932 unigenes were identified as hub genes with central roles in regulation of litchi floral induction. The expression of litchi homologs of well-known flowering genes was also investigated, and one Flowering Locus T (FT) homolog may play a crucial role in litchi flowering in responses to drought and low temperature. PMID:27557749

  7. Numerical Simulation of Non-Rotating and Rotating Coolant Channel Flow Fields. Part 1

    NASA Technical Reports Server (NTRS)

    Rigby, David L.

    2000-01-01

    Future generations of ultra high bypass-ratio jet engines will require far higher pressure ratios and operating temperatures than those of current engines. For the foreseeable future, engine materials will not be able to withstand the high temperatures without some form of cooling. In particular the turbine blades, which are under high thermal as well as mechanical loads, must be cooled. Cooling of turbine blades is achieved by bleeding air from the compressor stage of the engine through complicated internal passages in the turbine blades (internal cooling, including jet-impingement cooling) and by bleeding small amounts of air into the boundary layer of the external flow through small discrete holes on the surface of the blade (film cooling and transpiration cooling). The cooling must be done using a minimum amount of air or any increases in efficiency gained through higher operating temperature will be lost due to added load on the compressor stage. Turbine cooling schemes have traditionally been based on extensive empirical data bases, quasi-one-dimensional computational fluid dynamics (CFD) analysis, and trial and error. With improved capabilities of CFD, these traditional methods can be augmented by full three-dimensional simulations of the coolant flow to predict in detail the heat transfer and metal temperatures. Several aspects of turbine coolant flows make such application of CFD difficult, thus a highly effective CFD methodology must be used. First, high resolution of the flow field is required to attain the needed accuracy for heat transfer predictions, making highly efficient flow solvers essential for such computations. Second, the geometries of the flow passages are complicated but must be modeled accurately in order to capture all important details of the flow. This makes grid generation and grid quality important issues. Finally, since coolant flows are turbulent and separated the effects of turbulence must be modeled with a low Reynolds number

  8. Temperature controller for a fluid cooled garment

    NASA Technical Reports Server (NTRS)

    Chambers, A. B.; Blackaby, J. R.; Billingham, J. (Inventor)

    1973-01-01

    An automatic controller for controlling the inlet temperature of the coolant to a fluid cooled garment without requiring skin sensors is described. Temperature is controlled by the wearer's evaporative water loss rate.

  9. Nuclear criticality safety assessment of the proposed CFC replacement coolants

    SciTech Connect

    Jordan, W.C.; Dyer, H.R.

    1993-12-01

    The neutron multiplication characteristics of refrigerant-114 (R-114) and proposed replacement coolants perfluorobutane (C{sub 4}F{sub 10}) and cycloperfluorobutane C{sub 4}F{sub 8}) have been compared by evaluating the infinite media multiplication factors of UF{sub 6}/H/coolant systems and by replacement calculations considering a 10-MW freezer/sublimer. The results of these comparisons demonstrate that R-114 is a neutron absorber, due to its chlorine content, and that the alternative fluorocarbon coolants are neutron moderators. Estimates of critical spherical geometries considering mixtures of UF{sub 6}/HF/C{sub 4}F{sub 10} indicate that the flourocarbon-moderated systems are large compared with water-moderated systems. The freezer/sublimer calculations indicate that the alternative coolants are more reactive than R-114, but that the reactivity remains significantly below the condition of water in the tubes, which was a limiting condition. Based on these results, the alternative coolants appear to be acceptable; however, several follow-up tasks have been recommended, and additional evaluation will be required on an individual equipment basis.

  10. Coolant mixing and distribution in a transparent reactor model

    SciTech Connect

    Fanning, M.W.; Haury, G.; Pflug, L.; Rothe, P.H.

    1983-11-01

    Following a small break loss-of-coolant accident in a pressurized water reactor, coolant water may be injected at high pressure to help cool the core. This paper reports the results of tests which determined the mixing and distribution of the coolant in a 1/5-scale transparent model of the reactor. The model components included the reactor vessel, cold leg pipe, pump, and loop seal with steam generator and hot leg simulators completing the flow loop. Tests were conducted for a no-refill condition with constant liquid inventory in the facility and zero flow of the primary water. Salt water, dyed red was used for the coolant water to create prototypical density differences in this atmospheric facility. Steady state fluid distribution was determined from flow and density measurements and complete mass balances. Interpretation of the quantitative results was aided by extensive flow visualization studies which include still photographs and motion picture films for all tests. The test parameters included the fluid density ratio, the flow rate of coolant water, and the flow rate of primary water injected in the vessel downcomer to simulate a natural circulation flow through vent valves between the reactor core and the downcomer. Four locations of the small break were tested.

  11. Diesel engine coolant analysis, new application for established instrumentation

    SciTech Connect

    Anderson, D.P.; Lukas, M.; Lynch, B.K.

    1998-09-01

    Rotating disk electrode (RDE) arc emission spectrometers are used in many commercial, industrial and military laboratories throughout the world to analyze millions of oil and fuel samples each year. In fact, RDE spectrometers have been used exclusively for oil and fuel analysis for so long, that most practitioners have probably forgotten that when RDE spectrometers were first introduced more than 40 years ago, they were also routinely used for aqueous samples. This paper describes recent work to calibrate and modify RDE arc emission spectrometers for the analysis of engine coolant samples; a mixture of approximately 50% water and 50% glycol. The technique has been shown to be effective for the analysis of wear metals, contamination and supplemental coolant additives in ethylene and propylene glycol. A comparison of results for coolant samples measured by both inductively coupled plasma (ICP) and RDE spectrometers will be presented. The data correlates extremely well on new and relatively clean coolants. However, not surprisingly, RDE results are sometimes higher for samples containing particles larger than a few micrometers. This paper suggests that RDE spectrometers are appropriate, and sometimes preferred, for most types of coolants and certain types of aqueous samples. Actual field data is be presented to support the arguments.

  12. Mechanism and estimation of fatigue crack initiation in austenitic stainless steels in LWR environments.

    SciTech Connect

    Chopra, O. K.; Energy Technology

    2002-08-01

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the Code specify fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. This report provides an overview of fatigue crack initiation in austenitic stainless steels in LWR coolant environments. The existing fatigue {var_epsilon}-N data have been evaluated to establish the effects of key material, loading, and environmental parameters (such as steel type, strain range, strain rate, temperature, dissolved-oxygen level in water, and flow rate) on the fatigue lives of these steels. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for austenitic stainless steels as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are presented. The influence of reactor environments on the mechanism of fatigue crack initiation in these steels is also discussed.

  13. Transcription of fractionated mammalian chromatin by mammalian ribonucleic acid polymerase. Demonstration of temperature-dependent rifampicin-resistant initiation sites in euchromatin deoxyribonucleic acid

    PubMed Central

    Chesterton, C. James; Coupar, Barbara E. H.; Butterworth, Peter H. W.

    1974-01-01

    The chromatin fractionation method of Frenster et al. (1963) as modified by Leake et al. (1972) was used to prepare fragments of euchromatin from rat liver nuclei. These remain soluble in 5mm-MgCl2, and contain DNA of maximum mol.wt. 1×106–2×106. The fragments were separated from condensable chromatin on a sucrose gradient. Euchromatin contains endogenous DNA-dependent RNA polymerase, and most of the nascent RNA labelled in vivo or in vitro. Euchromatin fragments allow initiation of transcription by added purified rat liver form-B RNA polymerase and contain temperature-dependent rifampicin-resistant initiation sites for the form-B enzyme. These findings indicate that transcription of the euchromatin regions of interphase chromosomes is not initiated in condensed chromatin, but is initiated within the euchromatin stretches. Condensable chromatin also contains most of these activities, but is not associated with nascent RNA. PMID:4464858

  14. Cladding embrittlement during postulated loss-of-coolant accidents.

    SciTech Connect

    Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division

    2008-07-31

    The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.

  15. Temperature-dependent orientation study of the initial growth of pentacene on amorphous SiO2 by molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Zeng, Yuanqi; Tao, Bo; Chen, Jiankui; Yin, Zhouping

    2015-11-01

    Temperature-dependent molecular orientations in the initial growth processes of pentacene on amorphous SiO2 surface with different substrate temperatures have been investigated using molecular dynamics simulations. As the substrate temperature ranges from 270 K to 600 K, there exists a transition behavior for pentacene cluster from the normal-oriented, ordered configuration to the lateral-oriented, disordered one as measured by the decreased average orientation angle and order parameter, showing the significant effect of the substrate temperature on the molecular orientation. The transition behavior is related to the strength relationship between molecule-molecule interactions and molecule-substrate interactions. During the optimal temperature range between 300 K and 350 K, the pentacene molecules tend to form the normal-oriented, well-ordered cluster driven by the dominant molecule-molecule interactions, which is affected by the substrate temperature in a greater degree than the molecule-substrate interactions. When the temperature is lower than 300 K, the ordering of pentacene cluster becomes a little worse. A higher substrate temperature results in the lateral orientation with the weakening of the molecule-molecule interactions. Then the further intensification of molecular thermal motion gradually makes the molecules separate from the cluster or the substrate surface, resulting in the appearance of the undesirable separated configuration.

  16. Actively controlling coolant-cooled cold plate configuration

    SciTech Connect

    Chainer, Timothy J.; Parida, Pritish R.

    2015-07-28

    A method is provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The method includes: monitoring a variable associated with at least one of the coolant-cooled cold plate or one or more electronic components being cooled by the cold plate; and dynamically varying, based on the monitored variable, a physical configuration of the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the one or more electronic components, and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the coolant-cooled cold plate, the positioning of which may be adjusted based on the monitored variable.

  17. Initial estimates of the temperature and fractional areas of fires at the World Trade Center Disaster from AVIRIS

    NASA Technical Reports Server (NTRS)

    Green, R. O.; Clark, R. N.; Boardman, J.; Pavri, B.; Sarture, C.

    2003-01-01

    This paper reports the measurements, algorithms, analyses, and results of the fire temperature and fractional area determinations with AVIRIS calibrated spectra at the World Trade Center site in September 2001.

  18. Magnet safety and stability related coolant states: critical fluid dynamics at peak flux

    NASA Astrophysics Data System (ADS)

    Ravikumar, K. V.; Carandang, R. M.; Frederking, T. H. K.

    The stability of superconducting magnets is endangered under certain distinct conditions of the fluid serving as magnet coolant. A severe compromising of safety takes place at the peak heat flux of nucleate boiling. Progress in analysing first order phase transitions for cryoliquids and room temperature liquids, in the presence of heat flow, has led to better understanding of the parameters related to vapour bubble phenomena. The present work addresses the consequences arising from bubble frequency results, including model calculations for the effective masses of the saturated fluids involved in the two-phase transport at the peak flux.

  19. Spectrophotometric Procedure for Fast Reactor Advanced Coolant Manufacture Control

    NASA Astrophysics Data System (ADS)

    Andrienko, O. S.; Egorov, N. B.; Zherin, I. I.; Indyk, D. V.

    2016-01-01

    The paper describes a spectrophotometric procedure for fast reactor advanced coolant manufacture control. The molar absorption coefficient of dimethyllead dibromide with dithizone was defined as equal to 68864 ± 795 l·mole-1·cm-1, limit of detection as equal to 0.583 · 10-6 g/ml. The spectrophotometric procedure application range was found to be equal to 37.88 - 196.3 g. of dimethyllead dibromide in the sample. The procedure was used within the framework of the development of the method of synthesis of the advanced coolant for fast reactors.

  20. Functional csdA is needed for effective adaptation and initiation of growth of Clostridium botulinum ATCC 3502 at suboptimal temperature.

    PubMed

    Söderholm, Henna; Derman, Yağmur; Lindström, Miia; Korkeala, Hannu

    2015-09-01

    The activity of RNA helicase csdA (cbo2802) after temperature downshift was compared to its activity at optimal growth temperature, and the effect of sense and antisense oriented insertional inactivation of cbo2802 on the growth of ATCC 3502 at suboptimal temperature was evaluated. The relative cbo2802 transcript level was significantly induced for 30min to 5h after cold shock. In contrast, a significant decrease in the relative transcript level of cbo2802 was observed within the same time frame at 37°C. Inactivation of cbo2802 led to an extensive delay in initiation of exponential growth at 20°C but not at 37°C. In addition, the mean minimum growth temperatures of the mutant strains were higher than those of the wild-type strain. During a 24-hour incubation at 37°C, all strains were motile, whereas at 20°C the mutant strains showed severely impaired motility compared to the wild-type strain. This study shows that a functional csdA is needed for effective adaptation and initiation of growth and motility of Clostridium botulinum ATCC 3502 at suboptimal temperature. PMID:26057109

  1. Impact of temperature on the ratio of initial emittable concentration to total concentration for formaldehyde in building materials: theoretical correlation and validation.

    PubMed

    Huang, Shaodan; Xiong, Jianyin; Zhang, Yinping

    2015-02-01

    The initial emittable concentration (Cm,0) is a key parameter characterizing the emission behaviors of formaldehyde from building materials, which is highly dependent on temperature but has seldom been studied. Our previous study found that Cm,0 is much less than the total concentration (C0,total, used for labeling material in many standards) of formaldehyde. Because Cm,0 and not C0,total directly determines the actual emission behaviors, we need to determine the relationship between Cm,0 and C0,total so as to use Cm,0 as a more appropriate labeling index. By applying statistical physics theory, this paper derives a novel correlation between the emittable ratio (Cm,0/C0,total) and temperature. This correlation shows that the logarithm of the emittable ratio multiplied by power of 0.5 of temperature is linearly related to the reciprocal of temperature. Emissions tests for formaldehyde from a type of medium density fiberboard over the temperature range of 25.0-80.0 °C were performed to validate the correlation. Experimental results indicated that Cm,0 (or emittable ratio) increased significantly with increasing temperature, this increase being 14-fold from 25.0 to 80.0 °C. The correlation prediction agreed well with experiments, demonstrating its effectiveness in characterizing physical emissions. This study will be helpful for predicting/controlling the emission characteristics of pollutants at various temperatures. PMID:25563933

  2. Initial evaluation of profiles of temperature, water vapor, and cloud liquid water from a new microwave profiling radiometer.

    SciTech Connect

    Liljegren, J. C.; Lesht, B. M.; Clothiaux, E. E.; Kato, S.

    2000-11-01

    To measure the vertical profiles of temperature and water vapor that are essential for modeling atmospheric processes, the Atmospheric Radiation Measurement (ARM) Program of the U. S. Department of Energy launches approximately 2600 radiosondes each year from its Southern Great Plains (SGP) facilities in Oklahoma and Kansas, USA. The annual cost of this effort exceeds $500,000 in materials and labor. Despite the expense, these soundings have a coarse temporal resolution and reporting interval compared with model time steps. In contrast, the radiation measurements used for model evaluations have temporal resolutions and reporting intervals of a few minutes at most. Conversely, radiosondes have a much higher vertical spatial resolution than most models can use. Modelers generally reduce the vertical resolution of the soundings by averaging over the vertical layers of the model. Recently, Radiometries Corporation (Boulder, Colorado, USA) developed a 12-channel, ground-based microwave radiometer capable of providing continuous, real-time vertical profiles of temperature, water vapor, and limited-resolution cloud liquid water from the surface to 10 km in nearly all weather conditions. The microwave radiometer profiler (MWRP) offers a much finer temporal resolution and reporting interval (about 10 minutes) than the radiosonde but a coarser vertical resolution that may be more appropriate for models. Profiles of temperature, water vapor, and cloud liquid water are obtained at 47 levels: from 0 to 1 km above ground level at 100-m intervals and from 1 to 10 km at 250-m intervals. The profiles are derived from the measured brightness temperatures with neural network retrieval. In Figure 1, profiles of temperature, water vapor, and cloud liquid water for 10 May 2000 are presented as time-height plots. MWRP profiles coincident with the 11:31 UTC (05:31 local) and 23:47 UTC (17:47 local) soundings for 10 May are presented in Figures 2 and 3, respectively. These profiles

  3. A passively-safe fusion reactor blanket with helium coolant and steel structure

    SciTech Connect

    Crosswait, K.M.

    1994-04-01

    Helium is attractive for use as a fusion blanket coolant for a number of reasons. It is neutronically and chemically inert, nonmagnetic, and will not change phase during any off-normal or accident condition. A significant disadvantage of helium, however, is its low density and volumetric heat capacity. This disadvantage manifests itself most clearly during undercooling accident conditions such as a loss of coolant accident (LOCA) or a loss of flow accident (LOFA). This thesis describes a new helium-cooled tritium breeding blanket concept which performs significantly better during such accidents than current designs. The proposed blanket uses reduced-activation ferritic steel as a structural material and is designed for neutron wall loads exceeding 4 MW/m{sup 2}. The proposed geometry is based on the nested-shell concept developed by Wong, but some novel features are used to reduce the severity of the first wall temperature excursion. These features include the following: (1) A ``beryllium-joint`` concept is introduced, which allows solid beryllium slabs to be used as a thermal conduction path from the first wall to the cooler portions of the blanket. The joint concept allows for significant swelling of the beryllium (10 percent or more) without developing large stresses in the blanket structure. (2) Natural circulation of the coolant in the water-cooled shield is used to maintain shield temperatures below 100 degrees C, thus maintaining a heat sink close to the blanket during the accident. This ensures the long-term passive safety of the blanket.

  4. Carbon partitioning and the impact of starch deficiency on the initial response of Arabidopsis to chilling temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Specific metabolites and RNA transcripts were measured in Arabidopsis thaliana leaves in response to chilling temperatures. During the first 24 h of cold treatment eight soluble carbohydrates increased 9.4 fold on average during cold treatment. Except for maltose and raffinose carbohydrate accumul...

  5. NMP and O2 as Radical Initiator: Trifluoromethylation of Alkenes to Tertiary β-Trifluoromethyl Alcohols at Room Temperature.

    PubMed

    Liu, Chao; Lu, Qingquan; Huang, Zhiyuan; Zhang, Jian; Liao, Fan; Peng, Pan; Lei, Aiwen

    2015-12-18

    A novel strategy was developed to trigger ·CF3 by using in situ generated peroxide in NMP under O2 or air as the radical initiator. Radical trifluoromethylation of alkenes was achieved toward tertiary β-trifluoromethyl alcohols. Various tertiary β-trifluoromethyl alcohols can be synthesized in good yields without extra oxidants or transition metal catalysts. Preliminary mechanistic investigation revealed that O2 diffusion can influence the reaction rate. PMID:26649920

  6. AUTOMOTIVE AND HEAVY-DUTY ENGINE COOLANT RECYCLING BY FILTRATION

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction and economic issues involved in recycling automotive and heavy-duty engine coolants. he specific recycling units evaluated are a fleet-size unit and a portable unit, both based on the technology of chemical filtration...

  7. PIPING FOR COOLANT WATER IS INSTALLED INSIDE REACTOR STRUCTURE PRIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PIPING FOR COOLANT WATER IS INSTALLED INSIDE REACTOR STRUCTURE PRIOR TO EMBEDMENT IN CONCRETE. HIGHER PIPE IS INLET; THE OTHER, THE OUTLET LOOP. INLET PIPE WILL CONNECT TO TOP SECTION OF REACTOR VESSEL. INL NEGATIVE NO. 1287. Unknown Photographer, 1/18/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. Coolant Characteristics and Control in Direct Chill Casting

    SciTech Connect

    2001-10-01

    This project focuses on understanding the fundamentals of coolant behavior and developing strategies to control the cooling rate of DC casting of aluminum ingots. Project partners will conduct a fundamental study to identify various parameters affecting critical heat flux and boiling transition and evaluate the effects of various additives (impurity particulates, sodium and calcium salts, carbonates, bicarbonates, surfactants, etc.).

  9. Coolants with selective optical filtering characteristics for ruby laser applications

    NASA Technical Reports Server (NTRS)

    Mc Devitt, F. R.; Rasquin, J. R.

    1968-01-01

    Coolant-filtering medium developed consists of a solution of copper sulfate in a 4-1 volumetric mixture of ethanol and methanol. This solution should be a useful addition to ruby laser systems, particularily in large pulse or Q switching applications.

  10. Integral coolant channels supply made by melt-out method

    NASA Technical Reports Server (NTRS)

    Escher, W. J. D.

    1964-01-01

    Melt-out method of constructing strong, pressure-tight fluid coolant channels for chambers is accomplished by cementing pins to the surface and by depositing a melt-out material on the surface followed by two layers of epoxy-resin impregnated glass fibers. The structure is heated to melt out the low-melting alloy.

  11. Fuels, Lubricants, and Coolants. FOS: Fundamentals of Service.

    ERIC Educational Resources Information Center

    John Deere Co., Moline, IL.

    This manual on fuels, lubricants, and coolants is one of a series of power mechanics tests and visual aids on automotive and off-the-road agricultural and construction equipment. Materials present basic information with illustrations for use by vocational students and teachers as well as shop servicemen and laymen. Focusing on fuels, the first of…

  12. AUTOMOTIVE AND HEAVY-DUTY ENGINE COOLANT RECYCLING BY DISTILLATION

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants for a facility such as the New Jersey Department of Transportation garage in Ewing, New Jersey. he specific recycling evaluated is b...

  13. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

  14. 37. Upper level, chromate tanks (formerly provided coolant to missile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. Upper level, chromate tanks (formerly provided coolant to missile guidance section, retractor cables for lock pin in front of ladder at left - Ellsworth Air Force Base, Delta Flight, Launch Facility, On County Road T512, south of Exit 116 off I-90, Interior, Jackson County, SD

  15. Antimony tartrate corrosion inhibitive composition for coolant systems

    SciTech Connect

    Payerle, N.E.

    1987-08-11

    An automobile coolant concentrate is described comprising (a) a liquid polyhydric alcohol chosen from the group consisting of ethylene glycol, propylene glycol, diethylene glycol and mixtures thereof, and (b) corrosion inhibitors in a corrosion inhibitory amount with respect to corrosion of lead-containing solders, the corrosion inhibitors comprising (i) an alkali metal antimony tartrate, and (ii) an azole compound.

  16. Thermal explosions resulting from fuel-coolant interactions

    SciTech Connect

    Bartusiak, R.D.; Caram, H.S.

    1988-08-01

    High-speed photographic data and pressure traces of thermal explosions from the contact of single drops of ion oxide with water were analyzed according to models describing underwater chemical explosion and cavitation bubbles. The objective was to develop a simple method for analyzing the microscale hydrodynamics of fuel-coolant interactions (FCI). For a given external pressure and liquid density essentially all the features of the radial motion of the explosion bubble, including the total energy release, are uniquely determined by a single parameter - the bubble period. Nearly all of the heat transfer from fuel to coolant occurs during the 10/sup -5/ to 10/sup -4/ sec timespan of coolant vapor film collapse during which the fuel fragments. The features of the resulting explosion bubble are not significantly affected by the degree of heat transfer from vapor to coolant liquid and the bubble can be modeled as an empty cavity. The method developed during this study should facilitate investigations on FCI by simplifying the analyses of thermal explosion data. Further attention can be given to experiments on the effects of fuel parameters, e.g., surface tension and viscosity, on fragmentation, heat transfer, and explosive yield.

  17. INVESTIGATION OF CLEANER TECHNOLOGIES TO MINIMIZE AUTOMOTIVE COOLANT WASTES

    EPA Science Inventory

    The U.S. Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. hese evaluations addressed the product quality, waste reduction, and eco...

  18. Directly connected heat exchanger tube section and coolant-cooled structure

    DOEpatents

    Chainer, Timothy J; Coico, Patrick A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E

    2014-04-01

    A cooling apparatus for an electronics rack is provided which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures and a tube. The heat exchanger, which is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of distinct, coolant-carrying tube sections, each tube section having a coolant inlet and a coolant outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.

  19. Experimental interaction of magma and “dirty” coolants

    NASA Astrophysics Data System (ADS)

    Schipper, C. Ian; White, James D. L.; Zimanowski, Bernd; Büttner, Ralf; Sonder, Ingo; Schmid, Andrea

    2011-03-01

    The presence of water at volcanic vents can have dramatic effects on fragmentation and eruption dynamics, but little is known about how the presence of particulate matter in external water will further alter eruptions. Volcanic edifices are inherently “dirty” places, where particulate matter of multiple origins and grainsizes typically abounds. We present the results of experiments designed to simulate non-explosive interactions between molten basalt and various “coolants,” ranging from homogeneous suspensions of 0 to 30 mass% bentonite clay in pure water, to heterogeneous and/or stratified suspensions including bentonite, sand, synthetic glass beads and/or naturally-sorted pumice. Four types of data are used to characterise the interactions: (1) visual/video observations; (2) grainsize and morphology of resulting particles; (3) heat-transfer data from a network of eight thermocouples; and (4) acoustic data from three force sensors. In homogeneous coolants with <~10% bentonite, heat transfer is by convection, and the melt is efficiently fragmented into blocky particles through multiple thermal granulation events which produce associated acoustic signals. For all coolants with >~20% sediment, heat transfer is by forced convection and conduction, and thermal granulation is less efficient, resulting in fewer blocky particles, larger grainsizes, and weaker acoustic signals. Many particles are droplet-shaped or/and “vesicular,” containing bubbles filled with coolant. Both of these particle types indicate significant hydrodynamic magma-coolant mingling, and many of them are rewelded into compound particles. The addition of coarse material to heterogeneous suspensions further slows heat transfer thus reducing thermal granulation, and variable interlocking of large particles prevents efficient hydrodynamic mingling. This results primarily in rewelded melt piles and inefficient distribution of melt and heat throughout the coolant volume. Our results indicate

  20. Initial proof-of-principle for near room temperature Xe and Kr separation from air with MOFs

    SciTech Connect

    Thallapally, Praveen K.; Strachan, Denis M.

    2012-06-06

    Materials were developed and tested in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Separations and Waste Forms Campaign. Specifically, materials are being developed for the removal of Xenon and krypton from gaseous products of nuclear fuel reprocessing unit operations. During FY 2012, Three Metal organic framework (MOF) structures were investigated in greater detail for the removal and storage of Xe and Kr from air at room temperature. Our breakthrough measurements on Nickel based MOF could capture and separate parts per million levels of Xe from Air (40 ppm Kr, 78% N2, 21% O2, 0.9% Ar, 0.03% CO2). Similarly, the selectivity can be changed from Xe > Kr to Xe < Kr simply by changing the temperature in another MOF. Also for the first time we estimated the cost of the metal organic frameworks in bulk.

  1. Fluid Pressure and Temperature Response at the Nankai Trough Megasplay Fault: Initial Results of the SmartPlug Borehole Observatory

    NASA Astrophysics Data System (ADS)

    Hammerschmidt, S.; Kopf, A.; Expedition 332 Scientists, T.

    2011-12-01

    The SmartPlug is the first borehole observatory in the IODP Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE). It was installed at Site C0010 where it penetrates one of the shallow branches of the Megasplay fault to obtain pressure and temperature data from the fault and from a hydrostatic reference section. Here, a 15 months-lasting pore pressure and temperature record collected by the SmartPlug was evaluated. The main objective was to clarify the origin of transients in the data and its possible relationship to natural processes such as earthquakes, tectonic deformation or splay fault activity, as well as storms or low-pressure weather systems. After pressure and temperature data were processed properly, comparisons were made using seismic data from the Japanese F-Net and Hi-Net, theoretical travel time calculations provided by the USGS as well as earthquake lists from the ISC. Additionally, meteorological data provided by the JMA and the U.S. COAPS as well as theoretical travel time calculations for tsunamis from the U.S. NGDC were used. It can be shown that pulse-like pressure transients are related to regional/teleseismic earthquakes, originating mainly from the "Pacific Ring of Fire", from various depths and with diverse focal mechanisms. Approaching seismic waves of at least one regional earthquake led to a significant drop in the formation pressure, which is interpreted as a seismic wave-induced increase in permeability. The arrival of Rayleigh waves caused amplification of the borehole pressure, probably due to induced fluid flow. Tremor-like pressure transients are interpreted to be microseism, which is, based on pressure transient characteristics, triggered by storms or low-pressure weather systems on the open ocean. Approaching tsunamis look similar but caused longer period oscillations in the pressure record. Mainly in the seafloor pressure data distinct peaks are visible, some of which look similar to distinct peaks in the temperature data

  2. Coolant pressure and airflow distribution in a strut-supported transpiration-cooled vane for a gas turbine engine

    NASA Technical Reports Server (NTRS)

    Kaufman, A.; Poferl, D. J.; Richards, H. T.

    1972-01-01

    An analysis to predict pressure and flow distribution in a strut-supported wire-cloth vane was developed. Results were compared with experimental data obtained from room-temperature airflow tests conducted over a range of vane inlet airflow rates from 10.7 to 40.4 g/sec (0.0235 to 0.0890 lb/sec). The analytical method yielded reasonably accurate predictions of vane coolant flow rate and pressure distribution.

  3. Fabrication and evaluation of temperature responsive molecularly imprinted sorbents based on surface of yeast via surface-initiated AGET ATRP

    NASA Astrophysics Data System (ADS)

    Pan, Jianming; Hang, Hui; Li, Xiuxiu; Zhu, Wenjing; Meng, Minjia; Dai, Xiaohui; Dai, Jiangdong; Yan, Yongsheng

    2013-12-01

    Temperature responsive molecularly imprinted polymers (T-MIPs) were prepared based on the surface of yeast by electron transfer atom transfer radical polymerization (AGET ATRP). The as-prepared T-MIPs were charcterized by FT-IR, SEM, TGA and elemental analysis, which indicated that T-MIPs exhibited thermal stability and composed of temperature responsive imprinted layer. Then T-MIPs were evaluated as sorbents to selectively recognise and release cefalexin (CFX) molecules. The results suggested binding properties of T-MIPs were related to the testing temperature. The maximum adsorption capacity of T-MIPs at 303 K was 59.4 mg g-1, and the maximum release proportion for T-MIPs at 293 K in water for 24 h was 71.08%. The selective recognition experiments demonstrated high affinity and selectivity of T-MIPs towards CFX over competitive compounds, and the specific recognition of binding sites may be based on the distinct size, structure and functional group to the template molecules.

  4. Effect of temperature on the initial stages of oxidation of γ-Al4Cu9(110)

    NASA Astrophysics Data System (ADS)

    Wardé, M.; Ledieu, J.; de Weerd, M.-C.; Fournée, V.; Barthés-Labrousse, M.-G.

    2015-08-01

    Combined X-ray photoemission spectroscopy and low energy electron diffraction investigations have been performed to study the influence of temperature on the first stages of oxidation of the (1 1 0) surface of γ-Al4Cu9 complex metallic alloy in the pressure range 2-6 × 10-7 mbar. The oxidation mechanism is driven by aluminium segregation. At 115 K, a pure aluminium oxide film is formed, which does not present any long range order. Cusbnd O bonds are never observed. The lower oxidation kinetics compared to that previously observed at room temperature is due to blocking of the oxygen dissociation and/or a decrease in the aluminium segregation. However, aluminium segregation is still observed, even for this very low temperature, due to the low energy value of the activation energy for aluminium diffusion in γ-Al4Cu9 (0.65 ± 0.12 eV) which is related to the presence of two vacancies in the crystal structure. At 925 K, fast aluminium segregation and possible oxygen diffusion into the bulk leads to the formation of domains or clusters of γ-like alumina either on top of or, more likely, below the surface.

  5. An Experimental Investigation and Correlation of the Heat Reduction to Nonporous Surfaces Behind a Porous Leading Edge Through Which Coolant is Ejected

    NASA Technical Reports Server (NTRS)

    Witte, William G.; Rashis, Bernard

    1960-01-01

    A configuration of a wing segment having constant chord thickness, 0 deg. sweep, a porous steel semicircular leading edge, and solid Inconel surfaces was tested in a Mach number 2.0 ethlyene-heated high-temperature air jet. Measurements were made of the wing surface temperatures at chordwise stations for several rates of helium flow through the porous leading edge. The investigation was conducted at stagnation temperatures ranging from 500 F to 2,400 F, at Reynolds numbers per foot ranging from 0.3 x 10(exp 7) to 1.2 x 10(exp 7), and at angles of attack of 0, +/- 5, and +/- 15 deg. The results indicated that the reduction of wing surface temperatures with respect to their values for no coolant flow, depended on the helium coolant flow rates and the distance behind the area of injection. The results were correlated in terms of the wall cooling parameter and the coolant flow-rate parameter, where the nondimensional flow rate was referenced to the cooled area up to the downstream position. For the same coolant flow rate, lower surface temperatures are achieved with a porous-wall cooling system. However, since flow-rate requirements decrease with increasing allowable surface temperatures, the higher allowable wall temperatures of the solid wall as compared to the structurally weaker porous wall- sharply reduce the flow-rate requirements of a downstream cooling system. Thus, for certain flight conditions it is possible to compensate for the lower efficiency of the downstream or solid-wall cooling system. For example, a downstream cooling system using solid walls that must be maintained at 1,800 F would require less coolant for Mach numbers up to 5.5 than would a porous-wall cooling system for which the walls must be maintained at temperatures less than or equal to 9000 F.

  6. LOSS-OF-COOLANT ACIDENT SIMULATIONS IN THE NATIONAL RESEARCH UNIVERSAL REACTOR

    SciTech Connect

    Bennett, W D; Goodman, R L; Heaberlin, S W; Hesson, G M; Nealley, C; Kirg, L L; Marshall, R K; McNair, G W; Meitzler, W D; Neally, G W; Parchen, L J; Pilger, J P; Rausch, W N; Russcher, G E; Schreiber, R E; Wildung, N J; Wilson, C L

    1981-02-01

    Pressurized water reactor loss-of-coolant accident (LOCA) phenomena are being simulated with a series of experiments in the U-2 loop of the National Research Universal Reactor at Chalk River, Ontario, Canada. The first of these experiments includes up to 45 parametric thermal-hydraulic tests to establish the relationship among the reflood delay time of emergency coolant, the reflooding rate, and the resultant fuel rod cladding peak temperature. Subsequent experiments establish the fuel rod failure characteristics at selected peak cladding temperatures. Fuel rod cladding pressurization simulates high burnup fission gas pressure levels of modern PWRs. This document contains both an experiment overview of the LOCA simulation program and a review of the safety analyses performed by Pacific Northwest Laboratory (PNL) to define the expected operating conditions as well as to evaluate the worst case operating conditions. The primary intent of this document is to supply safety information required by the Chalk River Nuclear Laboratories (CRNL), to establish readiness to proceed from one test phase to the next and to establish the overall safety of the experiment. A hazards review summarizes safety issues, normal operation and three worst case accidents that have been addressed during the development of the experiment plan.

  7. Modular Porous Plate Sublimator /MPPS/ requires only water supply for coolant

    NASA Technical Reports Server (NTRS)

    Rathbun, R. J.

    1966-01-01

    Modular porous plate sublimators, provided for each location where heat must be dissipated, conserve the battery power of a space vehicle by eliminating the coolant pump. The sublimator requires only a water supply for coolant.

  8. Local heat transfer in internally cooled turbine airfoil leading edge regions. I - Impingement cooling without film coolant extraction. II - Impingement cooling with film coolant extraction

    NASA Astrophysics Data System (ADS)

    Bunker, R. S.; Metzger, D. E.

    The highly localized internal heat transfer characteristics of large-scale models of impingement-cooled turbine blade leading edge regions presently studied derives its cooling from a single line of equally-spaced multiple jets aimed at the leading-edge apex, and exiting the leading-edge region in the opposite or chordwise direction. Detailed two-dimensional local surface Nusselt number distributions have been obtained with temperature-indicating coatings. Results indicate generally increasing heat transfer with the 0.6 power of jet Reynolds number. In the second part of this study, in which the same cooling process is used in conjunction with the extraction of the coolant fluid, the results obtained indicate that heat transfer is primarily dependent on jet Reynolds number, with smaller influences from the flow-extraction rate.

  9. Development of Safety Analysis Codes and Experimental Validation for a Very High Temperature Gas-Cooled Reactor

    SciTech Connect

    Chang, H. Oh, PhD; Cliff Davis; Richard Moore

    2004-11-01

    The very high temperature gas-cooled reactors (VHTGRs) are those concepts that have average coolant temperatures above 900 degrees C or operational fuel temperatures above 1250 degrees C. These concepts provide the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation and nuclear hydrogen generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperatures to support process heat applications, such as desalination and cogeneration, the VHTGR's higher temperatures are suitable for particular applications such as thermochemical hydrogen production. However, the high temperature operation can be detrimental to safety following a loss-of-coolant accident (LOCA) initiated by pipe breaks caused by seismic or other events. Following the loss of coolant through the break and coolant depressurization, air from the containment will enter the core by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structures and fuel. The oxidation will release heat and accelerate the heatup of the reactor core. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. The Idaho National Engineering and Environmental Laboratory (INEEL) has investigated this event for the past three years for the HTGR. However, the computer codes used, and in fact none of the world's computer codes, have been sufficiently developed and validated to reliably predict this event. New code development, improvement of the existing codes, and experimental validation are imperative to narrow the uncertaninty in the predictions of this type of accident. The objectives of this Korean/United States collaboration are to develop advanced computational methods for VHTGR safety analysis codes and to validate these computer codes.

  10. Visualizing Coolant Flow in Sodium Reactor Subassemblies

    SciTech Connect

    2010-01-01

    Uniformity of temperature controls peak power output. Interchannel cross-flow is the principal cross-assembly energy transport mechanism. The areas of fastest flow all occur at the exterior of the assembly. Further, the fast moving region winds around the assembly in a continuous swath. This Nek5000 simulation uses an unstructured mesh with over one billion grid points, resulting in five billion degrees of freedom per time slice. High speed patches of turbulence due to vertex shedding downstream of the wires persist for about a quarter of the wire-wrap periodic length. Credits: Science: Paul Fisher and Aleks Obabko, Argonne National Laboratory
 Visualization: Hank Childs and Janet Jacobsen, Lawrence Berkeley National Laboratory

 This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Dept. of Energy under contract DE-AC02-06CH11357. This research was sponsored by the Department of Energy's Office of Nuclear Energy's NEAMS program.

  11. Effects of realistic land surface initializations on subseasonal to seasonal soil moisture and temperature predictability in North America and in changing climate simulated by CCSM4

    NASA Astrophysics Data System (ADS)

    Kumar, Sanjiv; Dirmeyer, Paul A.; Lawrence, David M.; DelSole, Timothy; Altshuler, Eric L.; Cash, Benjamin A.; Fennessy, Michael J.; Guo, Zhichang; Kinter, James L.; Straus, David M.

    2014-12-01

    Fully coupled global climate model experiments are performed using the Community Climate System Model version 4.0 (CCSM4) for preindustrial, present, and future climate to study the effects of realistic land surface initializations on subseasonal to seasonal climate forecasts. Model forecasts are verified against model control simulations (perfect model experiments), thus overcoming to some extent issues of uncertainties in the observations and/or model parameterizations. Findings suggest that realistic land surface initialization is important for climate predictability at subseasonal to seasonal time scales. We found the highest predictability for soil moisture, followed by evapotranspiration, temperature, and precipitation. The predictability is highest for the 16 to 30 days forecast period, and it progressively decreases for the second and third month forecasts. We found significant changes in the spatial distributions of temperature predictability in the present and future climate compared to the preindustrial climate, although the spatial average changes for North America were rather small (<10%). To attribute the potential cause of changes in land-driven temperature predictability, they are correlated with the changes in land related climate metrics. The changes in temperature predictability are positively (0.40), and negatively (-0.35) correlated with the changes in nonrainy days evaporative fraction, and changes in dryness index respectively. From this result, the hypothesis arises that wetter conditions favor higher land-driven temperature predictability in North America. We tested the hypothesis by rearranging the predictability experiment ensembles and found support for the hypothesis in the midlatitude regions and short-term forecasts (16 to 30 days).

  12. Effect of Boron Addition and Initial Heat-Treatment Temperature on Microstructure and Mechanical Properties of Modified 9Cr-1Mo Steels Under Different Heat-Treatment Conditions

    NASA Astrophysics Data System (ADS)

    Das, C. R.; Albert, S. K.; Bhaduri, A. K.; Murty, B. S.

    2013-05-01

    The effect of initial heat treatment on microstructure and mechanical properties of boron-free and boron-containing modified 9Cr-1Mo steel (P91 and P91B, respectively) has been studied under different heat-treatment conditions. The prior austenite grains evolved in P91 steel, having different prior austenite grain sizes, were found to be similar in size after heat treatment in the range of 1073 K to 1448 K (800 °C to 1175 °C) for 5 minutes. The microstructural evolution in P91B steel having different prior austenite grain sizes appeared to be uniform when subjected to different heat-treatment temperatures with the prior austenite grain size being similar to that of initial grain size. Lath martensite was observed in P91B steel after all heat treatments. On the other hand, lath martensite was observed in P91 steel only when subjected to high-temperature heat treatment, whereas subgrain/substructure as well as coarse precipitates were observed after a lower temperature heat treatment. Large differences in the hardness/strength values between different microstructures corresponding to coarse-grained heat-affected zone (CGHAZ) and intercritical HAZ (ICHAZ) of P91 steel weldment were due to the distinct difference in these microstructures. The difference in hardness/strength values between the CGHAZ and ICHAZ was found to be insignificant in P91B steel under similar heat-treatment conditions.

  13. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Acceptance criteria for reactor coolant system venting... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high point vents for the reactor coolant system, for the reactor vessel head, and for other systems...

  14. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Acceptance criteria for reactor coolant system venting... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high point vents for the reactor coolant system, for the reactor vessel head, and for other systems...

  15. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Acceptance criteria for reactor coolant system venting... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high point vents for the reactor coolant system, for the reactor vessel head, and for other systems...

  16. Directly connected heat exchanger tube section and coolant-cooled structure

    DOEpatents

    Chainer, Timothy J.; Coico, Patrick A.; Graybill, David P.; Iyengar, Madhusudan K.; Kamath, Vinod; Kochuparambil, Bejoy J.; Schmidt, Roger R.; Steinke, Mark E.

    2015-09-15

    A method is provided for fabricating a cooling apparatus for cooling an electronics rack, which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures, and a tube. The heat exchanger is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of coolant-carrying tube sections, each tube section having a coolant inlet and outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.

  17. New Hydrophilic, Composite Membranes for Air Removal from Water Coolant Systems

    NASA Technical Reports Server (NTRS)

    Ritchie, Stephen M. C.; Luo, Qiang; Curtis, Salina S.; Holladay, Jon B.; Clark, Dallas W.

    2004-01-01

    Liquid coolants are commonly used as thermal transport media to increase efficiency and flexibility in aerospace vehicle design. The introduction of gas bubbles into the coolant can have negative consequences, including: loss of centrifugal pump prime, irregular sensor readings, and blockage of coolant flow to remote systems. One solution to mitigate these problems is the development of a passive gas removal device, or gas trap, installed in the flight cooling system. In this study, a new hydrophilic, composite membrane has been developed for passage of the coolant fluid and retention of gas bubbles. The trapped bubbles are subsequently vented from the system by a thin, hydrophobic, microporous membrane. The original design for this work employed a homogeneous membrane that was susceptible to fouling and pore plugging. Spare gas traps of this variety have degraded during storage, and recreation of the membranes has been complicated due to problems with polymer duplication and property variations in the final membranes. In this work, replacements have been developed based on deposition of a hydrophilic polymer on the bore-side of a porous polyethylene (PE) tube. The tube provides excellent chemical and mechanical stability, and the hydrophilic layer provides retention of gas bubbles. Preliminary results have shown that intimate contact is required between the deposited layer and the substrate to overcome material differences. This has been accomplished by presoaking the membrane tube in the solvent to raise its surface energy. Polymer solutions of various concentrations have been used to promote penetration of the polymer layer into the porous substrate and to control separation layer thickness. The resulting composite membranes have shown repeatable decrease in nitrogen permeability, which is indicative of a decrease in membrane pore size. Studies with water permeation have yielded similar results. We have observed some swelling of the added polymer layer, which

  18. Grafting of Poly(methyl methacrylate) Brushes from Magnetite Nanoparticles Using a Phosphonic Acid Based Initiator by Ambient Temperature Atom Transfer Radical Polymerization (ATATRP)

    PubMed Central

    2008-01-01

    Poly(methyl methacrylate) in the brush form is grown from the surface of magnetite nanoparticles by ambient temperature atom transfer radical polymerization (ATATRP) using a phosphonic acid based initiator. The surface initiator was prepared by the reaction of ethylene glycol with 2-bromoisobutyrl bromide, followed by the reaction with phosphorus oxychloride and hydrolysis. This initiator is anchored to magnetite nanoparticles via physisorption. The ATATRP of methyl methacrylate was carried out in the presence of CuBr/PMDETA complex, without a sacrificial initiator, and the grafting density is found to be as high as 0.90 molecules/nm2. The organic–inorganic hybrid material thus prepared shows exceptional stability in organic solvents unlike unfunctionalized magnetite nanoparticles which tend to flocculate. The polymer brushes of various number average molecular weights were prepared and the molecular weight was determined using size exclusion chromatography, after degrafting the polymer from the magnetite core. Thermogravimetric analysis, X-ray photoelectron spectra and diffused reflection FT-IR were used to confirm the grafting reaction.

  19. A review of the effects of coolant environments on the fatigue life of LWR structural materials.

    SciTech Connect

    Chopra, O. K.; Shack, W. J.

    2009-04-01

    The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code specifies design curves for the fatigue life of structural materials in nuclear power plants. However, the effects of light water reactor (LWR) coolant environments were not explicitly considered in the development of the design curves. The existing fatigue-strain-versus-life ({var_epsilon}-N) data indicate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. Under certain environmental and loading conditions, fatigue lives in water relative to those in air can be a factor of 15 lower for austenitic stainless steels and a factor of {approx}30 lower for carbon and low-alloy steels. This paper reviews the current technical basis for the understanding of the fatigue of piping and pressure vessel steels in LWR environments. The existing fatigue {var_epsilon}-N data have been evaluated to identify the various material, environmental, and loading parameters that influence fatigue crack initiation and to establish the effects of key parameters on the fatigue life of these steels. Statistical models are presented for estimating fatigue life as a function of material, loading, and environmental conditions. An environmental fatigue correction factor for incorporating the effects of LWR environments into ASME Code fatigue evaluations is described. This paper also presents a critical review of the ASME Code fatigue design margins of 2 on stress (or strain) and 20 on life and assesses the possible conservatism in the current choice of design margins.

  20. Improvised source of water coolant for ultrasonic scaler: an appropriate technology in underserved communities.

    PubMed

    Ibiyemi, Olushola; Taiwo, Juliana O; Oke, Gbemisola A

    2012-10-01

    Traditionally dental plaque, calculus and stains have been removed by scaling and polishing manually with hand instruments such as curettes, chisels, hoes and scalers. However, ultrasonic scaling is becoming the preferred method of initial periodontal treatment and maintenance, due to improved patient and operator comfort. Ultrasonic scaling can be performed effectively using pipe-borne water as coolant. However, such a water supply is unavailable in many rural dental clinics, especially in underserved communities in Nigeria. This article reports on an improvised source of water coolant, designed and fabricated to make modern, easy and effective plaque control available to people in communities where there is no pipe-borne water. The device will improve operator efficiency in tooth cleaning and patient compliance with treatment. Due to its simple design but effective function, the device is ideal for use in Nigeria's primary healthcare delivery program, offering enhanced preventive and curative services to remote, rural and semi-urban populations. In doing so oral health can be improved with a reduction in the incidence of oral diseases. PMID:23276120

  1. Methods for incorporating effects of LWR coolant environment into ASME code fatigue evaluations.

    SciTech Connect

    Chopra, O. K.

    1999-04-15

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Appendix I to Section HI of the Code specifies design fatigue curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of LWR environments on the fatigue resistance of carbon and low-alloy steels and austenitic stainless steels (SSs). Under certain loading and environmental conditions, fatigue lives of carbon and low-alloy steels can be a factor of {approx}70 lower in an LWR environment than in air. These results raise the issue of whether the design fatigue curves in Section III are appropriate for the intended purpose. This paper presents the two methods that have been proposed for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations. The mechanisms of fatigue crack initiation in carbon and low-alloy steels and austenitic SSs in LWR environments are discussed.

  2. Component evaluation for intersystem loss-of-coolant accidents in advanced light water reactors

    SciTech Connect

    Ware, A.G.

    1994-07-01

    Using the methodology outlined in NUREG/CR-5603 this report evaluates (on a probabilistic basis) design rules for components in ALWRs that could be subjected to intersystem loss-of-coolant accidents (ISLOCAs). The methodology is intended for piping elements, flange connections, on-line pumps and valves, and heat exchangers. The NRC has directed that the design rules be evaluated for BWR pressures of 7.04 MPa (1025 psig), PWR pressures of 15.4 MPa (2235 psig), and 177{degrees}C (350{degrees}F), and has established a goal of 90% probability that system rupture will not occur during an ISLOCA event. The results of the calculations in this report show that components designed for a pressure of 0.4 of the reactor coolant system operating pressure will satisfy the NRC survival goal in most cases. Specific recommendations for component strengths for BWR and PWR applications are made in the report. A peer review panel of nationally recognized experts was selected to review and critique the initial results of this program.

  3. Investigation into the Mpemba Effect: Variation in the Freezing Time of Water Dependent on Initial Temperature and Purity

    NASA Astrophysics Data System (ADS)

    Thvedt, Ingrid; Roseberry, Martha; Lehman, Susan

    2009-03-01

    The observation that hot water sometimes appears to freeze more quickly than cold water, known as the Mpemba effect, has generated vigorous debate. Prior research [1] into the Mpemba effect has resulted in conflicting results, due to a variety of observation techniques, multiple definitions of freezing, and different water treatments. To clarify the previous results, we have tested multiple types of water and improved the sample monitoring. During cooling and freezing, each 50 g water sample is continually monitored by three thermistors at different depths. Samples of tap, distilled, and nanopure water were heated, heated and cooled, or boiled before being frozen. We monitor the time to reach freezing, the duration of freezing, and the total time to reach -7^oC. We observe the Mpemba effect most consistently in the length of the freezing transition in tap water. Observations of temperature variation during freezing will also be presented. [1] See the review by M. Jeng, Am.J.Phys. 74 514 (2006).

  4. Experiment Operations Plan for a Loss-of-Coolant Accident Simulation in the National Research Universal Reactor Materials Tests 1 and 2

    SciTech Connect

    Russcher, G. E.; Wilson, C. L.; Marshall, R, K.; King, L. L.; Parchen, L. J.; Pilger, J. P.; Hesson, G. M.; Mohr, C. L.

    1981-09-01

    A loss of Coolant Accident (LOCA) simulation program is evaluating the thermal-hydraulic and mechanical effects of LOCA conditions on pressurized water reactor test fuel bundles. This experiment operation plan for the second and third experiments of the program will provide peak fuel cladding temperatures of up to 1172K (1650{degree}F) and 1061K (1450{degree}) respectively. for a long enough time to cause test fuel cladding deformation and rupture in both. Reflood coolant delay times and the reflooding rates for the experiments were selected from thermal-hydraulic data measured in the National Research Universal (NRU) reactor facilities and test train assembly during the first experiment.

  5. Health physics aspects of processing EBR-I coolant

    SciTech Connect

    Burke, L.L.; Thalgott, J.O.; Poston, J.W. Jr.

    1998-12-31

    The sodium-potassium reactor coolant removed from the Experimental Breeder Reactor Number One after a partial reactor core meltdown had been stored at the Idaho National Engineering and Environmental Laboratory for 40 years. The State of Idaho considered this waste the most hazardous waste stored in the state and required its processing. The reactor coolant was processed in three phases. The first phase converted the alkali metal into a liquid sodium-potassium hydroxide. The second phase converted this caustic to a liquid sodium-potassium carbonate. The third phase solidified the sodium-potassium carbonate into a form acceptable for land disposal. Health physics aspects and dose received during each phase of the processing are discussed.

  6. Glycol coolants improve heat transfer and corrosion control

    SciTech Connect

    Holfield, R.

    1995-03-01

    Various liquids from plain water to exotic fluids have been used as coolants in large stationary diesel engines that drive compressors on natural gas pipeline distribution systems. Although water is an efficient heat transfer medium, its drawbacks of freezing at {minus}32 F and boiling at 212 F seriously limit its usefulness. Special glycol-based heat transfer fluids are available and refined specifically for long-term needs of gas compressor engines. Appropriate corrosion inhibitors have been formulated for metallurgy and operating conditions encountered with these engines. Propylene glycol was developed as an alternative for use in environmentally sensitive areas. Glycol-based fluids must be specifically inhibited for industrial applications because uninhibited or improperly inhibited coolants can seriously damage reciprocating engines.

  7. Three dimensional calculations of the primary coolant flow in a 900 MW PWR vessel. Steady state and transient computations

    SciTech Connect

    Martin, A.; Alvarez, D.; Cases, F.

    1996-06-01

    After the Tchernobyl accident a working group was created to analyze the French PWR Safety with a respect to potential risk of reactivity accident. Potentially risky situations are those which can lead to heterogeneous boron concentration or temperature of the primary coolant fluid. This paper reports a Research and Development action based on numerical simulations and experiments on the primary coolant temperature or boron mixing capabilities in a PWR vessel. New numerical results obtained with the thermal hydraulic Finite Element (FE) Code N3S are presented. In these calculations the FE mesh takes into account the geometry of the lower plenum plates and columns. Two configurations have been investigated The first one is a steady state fluid flow mixing case. The reactor is cooled by free convection and the three loops, balanced in mass flow rate, are in operation. The second is a free boron plug transient case. It is related to the mixing of a clear plug injected in the vessel when a primary coolant pump starts-up. Two clear plug volumes have been investigated (3 and 8 m{sup 3}). Comparisons between these new numerical results and the data previously obtained (see Alvarez et al., 1992, Alvarez, Martin and Schneider, 1994) are presented in this paper.

  8. Death of enterohemorrhagic Escherichia coli O157:H7 in real mayonnaise and reduced-calorie mayonnaise dressing as influenced by initial population and storage temperature.

    PubMed Central

    Hathcox, A K; Beuchat, L R; Doyle, M P

    1995-01-01

    This study was undertaken to determine the survivability of low-density populations (10(0) and 10(2) CFU/g) of enterohemorrhagic Escherichia coli O157:H7 inoculated into real mayonnaise and reduced-calorie mayonnaise dressing and stored at 20 and 30 degrees C, temperatures within the range used for normal commercial mayonnaise distribution and storage. Inactivation patterns at 5 degrees C and inactivation of high-inoculum populations (10(6) CFU/g) were also determined. The pathogen did not grow in either mayonnaise formulation, regardless of the inoculum level or storage temperature. Increases in storage temperature from 5 to 20 degrees C and from 20 to 30 degrees C resulted in dramatic increases in the rate of inactivation. Populations of E. coli O157:H7 in the reduced-calorie and real formulations inoculated with a population of 0.23 to 0.29 log10 CFU/g and held at 30 degrees C were reduced to undetectable levels within 1 and 2 days, respectively; viable cells were not detected after 1 day at 20 degrees C. In mayonnaise containing an initial population of 2.23 log10 CFU/g, viable cells were not detected after 4 days at 30 degrees C or 7 days at 20 degrees C; tolerance was greater in real mayonnaise than in reduced-calorie mayonnaise dressing stored at 5 degrees C. The tolerance of E. coli O157:H7 inoculated at the highest population density (6.23 log 10 CFU/g) was less in reduced-calorie mayonnaise dressing than in real mayonnaise at all storage temperatures. In reduced-calorie mayonnaise dressing and real mayonnaise initially containing 2.23 log10 CFU/g, levels were undetectable after 28 and 58 days at 5 degrees C, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8534084

  9. EXPERIMENT OPERATIONS PLAN FOR A LOSS-OF-COOLANT ACCIDENT SIMULATION IN THE NATIONAL RESEARCH UNIVERSAL REACTOR

    SciTech Connect

    Russcher, G. E.; Cannon, L. W.; Goodman, R. L.; Hesson, G. M.; King, L. L.; McDuffie, P. N.; Marshall, R. K.; Nealley, C.; Pilger, J. P.; Mohr, C. L.

    1981-04-01

    Pressurized water reactor loss-of-coolant accident phenomena are being simulated with a series of experiments in the U-2 loop of the National Research Universal Reactor at Chalk River, Ontario, Canada. The first of these experiments includes up to 45 parametric thermal-hydraulic tests to establish the relationship between the reflood delay time of emergency coolant, the reflooding rate, and the resultant fuel rod cladding peak temperature. This document contains both experiment proposal and assembly proposal information. The intent of this document is to supply information required by the Chalk River Nuclear Laboratories (CRNL), and to identify the planned procedures and data that will be used both to establish readiness to proceed from one test phase to the next and to operate the experiment. Operating control settings and limits are provided for both experimenter systems and CRNL systems. A hazards review summarizes safety issues that have been addressed during the development of the experiment plan.

  10. An Analysis of an Automatic Coolant Bypass in the International Space Station Node 2 Internal Active Thermal Control System

    NASA Technical Reports Server (NTRS)

    Clanton, Stephen E.; Holt, James M.; Turner, Larry D. (Technical Monitor)

    2001-01-01

    A challenging part of International Space Station (ISS) thermal control design is the ability to incorporate design changes into an integrated system without negatively impacting performance. The challenge presents itself in that the typical ISS Internal Active Thermal Control System (IATCS) consists of an integrated hardware/software system that provides active coolant resources to a variety of users. Software algorithms control the IATCS to specific temperatures, flow rates, and pressure differentials in order to meet the user-defined requirements. What may seem to be small design changes imposed on the system may in fact result in system instability or the temporary inability to meet user requirements. The purpose of this paper is to provide a brief description of the solution process and analyses used to implement one such design change that required the incorporation of an automatic coolant bypass in the ISS Node 2 element.

  11. Expert system for online surveillance of nuclear reactor coolant pumps

    DOEpatents

    Gross, Kenny C.; Singer, Ralph M.; Humenik, Keith E.

    1993-01-01

    An expert system for online surveillance of nuclear reactor coolant pumps. This system provides a means for early detection of pump or sensor degradation. Degradation is determined through the use of a statistical analysis technique, sequential probability ratio test, applied to information from several sensors which are responsive to differing physical parameters. The results of sequential testing of the data provide the operator with an early warning of possible sensor or pump failure.

  12. Experimental investigations of thermal interaction between corium and coolants

    NASA Astrophysics Data System (ADS)

    Zagorul'ko, Yu. I.; Zhmurin, V. G.; Volov, A. N.; Kovalev, Yu. P.

    2008-03-01

    We present a generalized analysis of the experimental results from investigations of thermal interaction in corium simulators (melts of thermite mixtures U + Mo3 and Zr + Fe2O3)-coolant (Na and H2O) systems. We also present the results from experimental assessments of the kinematic characteristics pertinent to the displacement of materials during the thermal interaction process and the coefficients for conversion of the corium thermal energy into mechanical work.

  13. 92. View of transmitter building no. 102 first floor coolant ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    92. View of transmitter building no. 102 first floor coolant process water tanks (sodium bisulfate solution), stainless steel, for electronic systems cooling in transmitter and MIP rooms. RCA Services Company 29 September, 1960, official photograph BMEWS Project by unknown photograph, Photographic Services, Riverton, NJ, BMEWS, clear as negative no. A-1226 - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  14. Crack stability analysis of low alloy steel primary coolant pipe

    SciTech Connect

    Tanaka, T.; Kameyama, M.; Urabe, Y.

    1997-04-01

    At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel than for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.

  15. Acceptance criteria for reactor coolant pumps and valves

    SciTech Connect

    Gupta, N.K.; Miller, R.F.; Sindelar, R.L.

    1993-05-01

    Each of the six primary coolant loop systems of the Savannah River Site (SRS) production reactors contains one reactor coolant pump, one PUMP suction side motor operated valve, and other smaller valves. The pumps me double suction, double volute, and radially split type pumps. The valves are different size shutoff and control valves rated from ANSI B16.5 construction class 150 to class 300. The reactor coolant system components, also known as the process water system (PWS), are classified as nuclear Safety Class I components. These components were constructed in the 1950`s in accordance with the then prevailing industry practices. No uniform construction codes were used for design and analysis of these components. However, no pressure boundary failures or bolting failures have ever been recorded throughout their operating history. Over the years, the in-service inspection (ISI) was limited to visual inspection of the pressure boundaries, and surface and volumetric examination of the pressure retaining bolts. Efforts are now underway to implement ISI requirements similar to the ASME Section XI requirements for pumps and valves. This report discusses the new ISI requirements which also call for volumetric examination of the pump casing and valve body welds.

  16. Study of Compatibility of Stainless Steel Weld Joints with Liquid Sodium-Potassium Coolants for Fission Surface Power Reactors for Lunar and Space Applications

    SciTech Connect

    Grossbeck, Martin; Qualls, Louis

    2015-07-31

    To make a manned mission to the surface of the moon or to Mars with any significant residence time, the power requirements will make a nuclear reactor the most feasible source of energy. To prepare for such a mission, NASA has teamed with the DOE to develop Fission Surface Power technology with the goal of developing viable options. The Fission Surface Power System (FSPS) recommended as the initial baseline design includes a liquid metal reactor and primary coolant system that transfers heat to two intermediate liquid metal heat transfer loops. Each intermediate loop transfers heat to two Stirling heat exchangers that each power two Stirling converters. Both the primary and the intermediate loops will use sodium-potassium (NaK) as the liquid metal coolant, and the primary loop will operate at temperatures exceeding 600°C. The alloy selected for the heat exchangers and piping is AISI Type 316L stainless steel. The extensive experience with NaK in breeder reactor programs and with earlier space reactors for unmanned missions lends considerable confidence in using NaK as a coolant in contact with stainless steel alloys. However, the microstructure, chemical segregation, and stress state of a weld leads to the potential for corrosion and cracking. Such failures have been experienced in NaK systems that have operated for times less than the eight year goal for the FSPS. For this reason, it was necessary to evaluate candidate weld techniques and expose welds to high-temperature, flowing NaK in a closed, closely controlled system. The goal of this project was to determine the optimum weld configuration for a NaK system that will withstand service for eight years under FSPS conditions. Since the most difficult weld to make and to evaluate is the tube to tube sheet weld in the intermediate heat exchangers, it was the focus of this research. A pumped loop of flowing NaK was fabricated for exposure of candidate weld specimens at temperatures of 600°C, the expected

  17. The calculational modeling of impurity mass transfer in NPP circuits with liquid metal coolant

    NASA Astrophysics Data System (ADS)

    Alexeev, V.; Kozlov, F.; Kumaev, V.; Orlova, E.; Klimanova, Yu; Torbenkova, I.

    2008-02-01

    The authors create three levels of models (one-dimensional, two-dimensional and three-dimensional) for estimation of impurity mass transfer in sodium circuits units as well as applicable computational programs. In the one-dimensional model the flow path elements are simulated by annular channels. The Lagrange coordinate system is used in the mathematical description of processes in channels. The two-dimensional model is based on the porous body approximation and enables one to simulate global spatial distributions of coolant flow velocity fields, coolant and fuel rods temperatures, and concentration distribution of transferred substances. The mathematical description of passive multicomponent impurity transfer is carried out using the system of the differential equations with sources and impurity diffusion, written for each component. The equations are solved by the finite-difference method. The developed version of the three-dimensional code is based on a general approach of the spatial three-dimensional description of thermal-hydraulic and mass-transfer processes in fuel rod bundles. The determining system of finite-difference equations of hydrodynamics and heat exchange is obtained using the control volume approach. As a result of the performed calculations, valuable data on corrosion products transfer in the primary circuit of the BN-600 reactor are obtained.

  18. Gas production and behavior in the coolant of the SP-100 Space Nuclear Power System

    SciTech Connect

    McGhee, J.M.

    1989-08-01

    The radiologic generation and subsequent behavior of helium gas in the lithium coolant of SP-100 class space nuclear power reactors was investigated analytically in a two part study. Part One of the study consisted of a calculation of coolant radiologic helium gas production rates in a SP-100 class reactor using the discrete ordinates code TWODANT. Cross sections were developed from ENDF/B-V data via the MATXS6s master cross section library. Cross sections were self shielded assuming one homogeneous core region, and doppler broadened to 1300 K using the cross section preparation code TRANSX. Calculations were performed using an S{sub 4}/P{sub 1} approximation and 80 neutron energy groups. Part Two of the study consisted of a theoretical investigation into the behavior of helium gas in the primary loop of lithium cooled space reactors. The SP-100 space power system was used as a representative of such a system. Topics investigated included: (1) heterogeneous and homogeneous nucleation; (2) bubble growth/collapse by diffusion, mechanical temperature/pressure effects, and coalescence; and, (3) the effects on bubble distribution of microgravity, magnetic fields, and inertially induced buoyancy. 104 refs., 78 figs., 28 tabs.

  19. Gas production and behavior in the coolant of the SP-100 space nuclear power system

    NASA Astrophysics Data System (ADS)

    McGhee, John Morton

    1989-08-01

    The radiologic generation and subsequent behavior of helium gas in the lithium coolant of SP-100 class space nuclear power reactors was investigated analytically in a two part study. Part One of the study consisted of a calculation of coolant radiologic helium gas production rates in a SP-100 class reactor using the discrete ordinates code TWODANT. Cross sections were developed from ENDF/B-V data via the MATXS6s master cross section library. Cross sections were self shielded assuming one homogeneous core region, and Doppler broadened to 1300 K using the cross section preparation code TRANSX. Calculations were performed using an S sub 4/P sub 1 approximation and 80 neutron energy groups. Part Two of the study consisted of a theoretical investigation into the behavior of helium gas in the primary loop of lithium cooled space reactors. The SP-100 space power system was used as a representative of such a system. Topics investigated included: (1) heterogeneous and homogeneous nucleation; (2) bubble growth/collapse by diffusion, mechanical temperature/pressure effects, and coalescence; and, (3) the effects on bubble distribution of microgravity, magnetic fields, and inertially induced buoyancy.

  20. Coral bleaching and mortality on artificial and natural reefs in Maldives in 1998, sea surface temperature anomalies and initial recovery.

    PubMed

    Edwards, A J; Clark, S; Zahir, H; Rajasuriya, A; Naseer, A; Rubens, J

    2001-01-01

    The bleaching and subsequent mortality of branching and massive corals on artificial and natural reefs in the central atolls of Maldives in 1998 are examined with respect to sea surface temperature (SST) anomalies. SST normally peaks in April-May in Maldives. The UK Meteorological Office's Global sea-Ice and SST data set version 2.3 b shows that in 1998 monthly mean SST was 1.2-4 S.D. above the 1950-1999 average during the warmest months (March-June), with the greatest anomaly in May of +2.1 degrees C. Bleaching was first reported in mid-April and was severe from late April to mid-May with some recovery evident by late-May. At least 98% of branching corals (Acroporidae, Pocilloporidae) on artificial structures deployed on a reef flat in 1990 died whereas the majority of massive corals (Poritidae, Faviidae, Agariciidae) survived the bleaching. The pre-bleaching coral community on the artificial reefs in 1994 was 95% branching corals and 5% massives (n = 1589); the post-bleaching community was 3% branching corals and 97% massives (n = 248). Significant reductions in live coral cover were seen at all natural reefs surveyed in the central atolls, with average live coral cover decreasing from about 42% to 2%, a 20-fold reduction from pre-bleaching levels. A survey of recruitment of juvenile corals to the artificial structures 10 months after the bleaching event showed that 67% of recruits (> or = 0.5 cm diameter) were acroporids and pocilloporids and 33% were from massive families (n = 202) compared to 94% and 6%, respectively, in 1990-1994 (n = 3136). Similar post-bleaching dominance of recruitment by branching corals was seen on nearby natural reef (78% acroporids and pocilloporids; 22% massives). A linear regression of April mean monthly SST against year was highly significant (p < 0.001) and suggests a rise of 0.16 degree C per decade. If this trend continues, by 2030 mean April SST in the central atolls will normally exceed the anomaly level at which corals appear

  1. Thermionic converter temperature controller

    DOEpatents

    Shaner, Benjamin J.; Wolf, Joseph H.; Johnson, Robert G. R.

    2001-04-24

    A method and apparatus for controlling the temperature of a thermionic reactor over a wide range of operating power, including a thermionic reactor having a plurality of integral cesium reservoirs, a honeycomb material disposed about the reactor which has a plurality of separated cavities, a solid sheath disposed about the honeycomb material and having an opening therein communicating with the honeycomb material and cavities thereof, and a shell disposed about the sheath for creating a coolant annulus therewith so that the coolant in the annulus may fill the cavities and permit nucleate boiling during the operation of the reactor.

  2. Chlorine atom-initiated low-temperature oxidation of prenol and isoprenol: The effect of C=C double bonds on the peroxy radical chemistry in alcohol oxidation

    DOE PAGESBeta

    Welz, Oliver; Savee, John D.; Osborn, David L.; Taatjes, Craig A.

    2014-07-04

    The chlorine atom-initiated oxidation of two unsaturated primary C5 alcohols, prenol (3-methyl-2-buten-1-ol, (CH3)2CCHCH2OH) and isoprenol (3-methyl-3-buten-1-ol, CH2C(CH3)CH2CH2OH), is studied at 550 K and low pressure (8 Torr). The time- and isomer-resolved formation of products is probed with multiplexed photoionization mass spectrometry (MPIMS) using tunable vacuum ultraviolet ionizing synchrotron radiation. The peroxy radical chemistry of the unsaturated alcohols appears much less rich than that of saturated C4 and C5 alcohols. The main products observed are the corresponding unsaturated aldehydes – prenal (3-methyl-2-butenal) from prenol oxidation and isoprenal (3-methyl-3-butenal) from isoprenol oxidation. No significant products arising from QOOH chemistry are observed. Thesemore » results can be qualitatively explained by the formation of resonance stabilized allylic radicals via H-abstraction in the Cl + prenol and Cl + isoprenol initiation reactions. The loss of resonance stabilization upon O2 addition causes the energies of the intermediate wells, saddle points, and products to increase relative to the energy of the initial radicals and O2. These energetic shifts make most product channels observed in the peroxy radical chemistry of saturated alcohols inaccessible for these unsaturated alcohols. The experimental findings are underpinned by quantum-chemical calculations for stationary points on the potential energy surfaces for the reactions of the initial radicals with O2. Under our conditions, the dominant channels in prenol and isoprenol oxidation are the chain-terminating HO2-forming channels arising from radicals, in which the unpaired electron and the –OH group are on the same carbon atom, with stable prenal and isoprenal co-products, respectively. These results suggest that the presence of C=C double bonds in alcohols will reduce low-temperature reactivity during autoignition.« less

  3. Failure probability of PWR reactor coolant loop piping. [Double-ended guillotine break

    SciTech Connect

    Lo, T.; Woo, H.H.; Holman, G.S.; Chou, C.K.

    1984-02-01

    This paper describes the results of assessments performed on the PWR coolant loop piping of Westinghouse and Combustion Engineering plants. For direct double-ended guillotine break (DEGB), consideration was given to crack existence probability, initial crack size distribution, hydrostatic proof test, preservice inspection, leak detection probability, crack growth characteristics, and failure criteria based on the net section stress failure and tearing modulus stability concept. For indirect DEGB, fragilities of major component supports were estimated. The system level fragility was then calculated based on the Boolean expression involving these fragilities. Indirect DEGB due to seismic effects was calculated by convolving the system level fragility and the seismic hazard curve. The results indicate that the probability of occurrence of both direct and indirect DEGB is extremely small, thus, postulation of DEGB in design should be eliminated and replaced by more realistic criteria.

  4. The role of mantle temperature and lithospheric thickness during initial oceanic crust production: numerical modelling constraints from the southern South Atlantic

    NASA Astrophysics Data System (ADS)

    Taposeea, C.; Armitage, J. J.; Collier, J.

    2015-12-01

    Evidence from seaward dipping reflector distributions has recently suggested that segmentation plays a major role in the pattern of volcanism during breakup, particularly in the South Atlantic. At a larger scale, variations in mantle temperature and lithosphere thickness can enhance or reduce volcanism. To understand what generates along strike variation of volcanism at conjugate margins, we measure the thickness of earliest oceanic crust in the South Atlantic, south of the Walvis and Rio Grande ridges. We use data from 29 published wide-angle and multichannel seismic profiles and at least 14 unpublished multichannel seismic profiles. A strong linear trend between initial oceanic crustal thickness and distance from hotspot centres, defined as the commencement of Walvis and Rio Grande ridges, with a regression coefficient of 0.7, is observed. At 450km south of the Walvis Ridge, earliest oceanic crustal thickness is found to be 11.7km. This reduces to 7.0km in the south at a distance of 1,420km. Such a linear trend suggests rift segmentation plays a secondary role on volcanism during breakup. To explore the cause of this trend, we use a 2D numerical model of extension capable of predicting the volume and composition of melt generated by decompressional melting during extension to steady state seafloor spreading. We explore the effect of both mantle temperature and lithosphere thickness on melt production with a thermal anomaly (hot layer) 100km thick located below the lithosphere with an excess temperature of 50-200°C, and lithospheric thickness ranging from 125-140km, covering the thickness range estimated from tomographic studies. By focusing on a set of key seismic profiles, we show a reduction in hot layer temperature is needed in order to match observed oceanic crustal thickness, even when the effect of north to south variations in lithosphere thickness are included. This model implies that the observed oceanic thickness requires the influence of a hot layer up

  5. Development of Safety Analysis Codes and Experimental Validation for a Very High Temperature Gas-Cooled Reactor - FY-05 Annual Report

    SciTech Connect

    Chang Oh

    2005-09-01

    The very high temperature gas-cooled reactors (VHTGRs) are those concepts that have average coolant temperatures above 9000C or operational fuel temperatures above 12500C. These concepts provide the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation and nuclear hydrogen generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperatures to support process heat applications, such as desalination and cogeneration, the VHTGR’s higher temperatures are suitable for particular applications such as thermochemical hydrogen production. However, the high temperature operation can be detrimental to safety following a loss-of-coolant accident (LOCA) initiated by pipe breaks caused by seismic or other events. Following the loss of coolant through the break and coolant depressurization, air from the containment will enter the core by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structures and fuel. The oxidation will release heat and accelerate the heatup of the reactor core. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. The Idaho National Laboratory (INL) has investigated this event for the past three years for the HTGR. However, the computer codes used, and in fact none of the world’s computer codes, have been sufficiently developed and validated to reliably predict this event. New code development, improvement of the existing codes, and experimental validation are imperative to narrow the uncertainty in the predictions of this type of accident. The objectives of this Korean/United States collaboration are to develop advanced computational methods for VHTGR safety analysis codes and to validate these computer codes.

  6. The temperature sensitivity of heterotrophic respiration controls initial conditions and soil carbon resilience to global warming in CMIP5 models (Invited)

    NASA Astrophysics Data System (ADS)

    Exbrayat, J.; Pitman, A. J.; Abramowitz, G.

    2013-12-01

    In recent years, biogeochemical models have been implemented in the land component of global circulation models to investigate the interactions between the global terrestrial carbon cycle, anthropogenic CO2 emissions and global warming. These models are now the state-of-the-art tools used in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and the Intergovernmental Panel on Climate Change fifth Assessment Report (IPCC AR5). Usually, in each grid cell microbial decomposition and routing of soil organic matter between pools of different turn-over time is modelled as a first-order kinetics controlled by a pool-specific residence time. It is adjusted by response functions to environmental conditions and then applied to the pool size. One result of this methodology is a six-fold range (~500 to 3,000 Pg C) variation in total soil carbon simulated at the end of the CMIP5 historical simulations (1850 - 2005). Resolving why this range exists is crucial to understanding the large CMIP5 ensemble spread in projected land-atmosphere fluxes. In this talk, we show that the present CMIP5 range is already established in 1850. We demonstrate that it is an artefact of the representation of microbial decomposition during model initialization under constant pre-industrial atmospheric CO2. We then use a simple model representative of the first-order parameterization of heterotrophic respiration (Rh) that is driven by primary productivity and soil temperature data from a representative global climate model. Our setup is able to reproduce the CMIP5 range in initial conditions by changing one parameter and the formulation of the temperature sensitivity of Rh. Further, we show that the global response of soil carbon during historical simulations and 21st century projections under the Representative Concentration Pathway 8.5 strongly depends on initial conditions in both our simple model and CMIP5 simulations. This can switch soils from a net sink to a net source of

  7. Development and Application of the Reactor Coolant On-Line Leakage Evaluation Model for Pressurized Water Reactors

    SciTech Connect

    Liang, Thomas K.S.; Hung, H.-J.; Chang, C.-J.

    2001-12-15

    With the consideration of mass unbalance, coolant shrinking, and compressibility, a model for reactor coolant leakage evaluation has been developed to quantify on-line the system leakage rate with conventional system measurements, regardless of where the leak occurs. This model has been derived from the system of total continuity, and it divides the reactor coolant system (RCS) into two regions, namely, the saturated and subcooled regions. The pressurizer is considered as a saturated region, and the remaining part of the RCS is regarded as a subcooled region. Taking the on-line measurements of the RCS including the RCS pressure, temperature, pressurizer water level, and charging and letdown flow rates, this model can directly evaluate on-line the RCS leakage rate. It is noted that this model is applicable only if the RCS remains subcooled. To verify the applicability of this model, data generated by RELAP5/MOD3 simulation and experimental measurements from the Institute of Nuclear Energy Research, Taiwan, Integral System Test Facility were adopted to assess this model. With further on-line verification against the Maanshan training simulator, this model was finally delivered to the Maanshan nuclear power plant (a three-looped Westinghouse pressurized water reactor) to assist the operator training and on-line evaluation of the RCS leakage rate. The smallest amount of leak flow that can be detected by the ROCK model is 3 gal/min.

  8. Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape

    NASA Technical Reports Server (NTRS)

    Smith, Alvin; Boyd, Ronald D., Sr.

    1989-01-01

    An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.

  9. Heat transfer characteristics for some coolant additives used for water cooled engines

    SciTech Connect

    Abou-Ziyan, H.Z.; Helali, A.H.B.

    1996-12-31

    Engine coolants contain certain additives to prevent engine overheating or coolant freezing in cold environments. Coolants, also, contain corrosion and rust inhibitors, among other additives. As most engines are using engine cooling solutions, it is of interest to evaluate the effect of engine coolants on the boiling heat transfer coefficient. This has its direct impact on radiator size and environment. This paper describes the apparatus and the measurement techniques. Also, it presents the obtained boiling heat transfer results at different parameters. Three types of engine coolants and their mixtures in distilled water are evaluated, under sub-cooled and saturated boiling conditions. A profound effect of the presence of additives in the coolant, on heat transfer, was clear since changes of heat transfer for different coolants were likely to occur. The results showed that up to 180% improvement of boiling heat transfer coefficient is experienced with some types of coolants. However, at certain concentrations other coolants provide deterioration or not enhancement in the boiling heat transfer characteristics. This investigation proved that there are limitations, which are to be taken into consideration, for the composition of engine coolants in different environments. In warm climates, ethylene glycol should be kept at the minimum concentration required for dissolving other components, whereas borax is beneficial to the enhancement of the heat transfer characteristics.

  10. Development and performance of a large-scale, transonic turbine blade cascade facility for aerodynamic studies of merging coolant-mainstream flows

    NASA Astrophysics Data System (ADS)

    Al-Sayeh, Amjad Isaaf

    1998-11-01

    , flow direction, total temperature and heavy gas concentration. Initial data are presented to demonstrate the range of the attainable operating parameters. The facility contains a number of adjustable components: the effects of these adjustments has been explored on pressure (Mach number) distributions in the approach duct, the exhaust duct and on the blades themselves. Boundary layer profiles have been determined in the approach duct for different inlet Mach numbers. The approach flow was affected by adjustments of the bleed system configuration. Shadowgraphs (still photos and video tapes) were taken that show clean, well-defined blade trailing edge shock patterns conforming to expectations. Good periodicity was demonstrated at subsonic speeds. At supersonic speeds the suction surface Mach number distributions, near the trailing edges, were found to be very sensitive to the angular setting and porosity of the nearby tailboard. The porous tailboards were effective in attenuating reflections of shocks incident on them. Solid tailboards (obtained by covering the perforated surface with tape) produced bifurcated Mach reflections. (Abstract shortened by UMI.)

  11. TRAC large-break loss-of-coolant accident analysis for the AP600 design

    SciTech Connect

    Lime, J.F.; Boyack, B.E.

    1994-02-01

    This report discusses a TRAC model of the Westinghouse AP600 advanced reactor design which has been developed for analyzing large-break loss-of-coolant accident (LBLOCA) transients. A preliminary LBLOCA calculation of a 80% cold-leg break has been performed with TRAC-PF1/MOD2. The 80% break size was calculated by Westinghouse to be the most severe large-break size. The LBLOCA transient was calculated to 92 s. Peak clad temperatures (PCT) were well below the Appendix K limit of 1478 K (2200{degrees}F). Transient event times and PCT for the TRAC calculation were in reasonable agreement with those calculated by Westinghouse using their WCOBRA/TRAC code.

  12. Oxidation of SiC cladding under Loss of Coolant Accident (LOCA) conditions in LWRs

    SciTech Connect

    Lee, Y.; Yue, C.; Arnold, R. P.; McKrell, T. J.; Kazimi, M. S.

    2012-07-01

    An experimental assessment of Silicon Carbide (SiC) cladding oxidation rate in steam under conditions representative of Loss of Coolant Accidents (LOCA) in light water reactors (LWRs) was conducted. SiC oxidation tests were performed with monolithic alpha phase tubular samples in a vertical quartz tube at a steam temperature of 1140 deg. C and steam velocity range of 1 to 10 m/sec, at atmospheric pressure. Linear weight loss of SiC samples due to boundary layer controlled reaction of silica scale (SiO{sub 2} volatilization) was experimentally observed. The weight loss rate increased with increasing steam flow rate. Over the range of test conditions, SiC oxidation rates were shown to be about 3 orders of magnitude lower than the oxidation rates of zircaloy 4. A SiC volatilization correlation for developing laminar flow in a vertical channel is formulated. (authors)

  13. Fuel rod mechanical deformation during the PBF/LOFT lead rod loss-of-coolant experiments

    SciTech Connect

    Varacalle, Jr., D. J.; MacDonald, P. E.; Shiozawa, S.; Driskell, W. E.

    1980-01-01

    Results of four PBF/LOFT Lead Rod (LLR) sequential blowdown tests conducted in the Power Burst Facility (PBF) are presented. Each test employed four separately shrouded fuel rods. The primary objective of the test series was to evaluate the extent of mechanical deformation that would be expected to occur to low pressure (0.1 MPa), light water reactor design fuel rods when subjected to a series of double ended cold leg break loss-of-coolant accident (LOCA) tests, and to determine whether subjecting these deformed fuel rods to subsequent testing would result in rod failure. The extent of mechanical deformation (buckling, collapse, or waisting of the cladding) was evaluated by comparison of cladding temperature and system pressure measurements with out-of-pile experimental data, and by posttest visual examinations and cladding diametral measurements.

  14. Liquid Cooling of Tractive Lithium Ion Batteries Pack with Nanofluids Coolant.

    PubMed

    Li, Yang; Xie, Huaqing; Yu, Wei; Li, Jing

    2015-04-01

    The heat generated from tractive lithium ion batteries during discharge-charge process has great impacts on the performances of tractive lithium ion batteries pack. How to solve the thermal abuse in tractive lithium ion batteries pack becomes more and more urgent and important for future development of electrical vehicles. In this work, TiO2, ZnO and diamond nanofluids are prepared and utilized as coolants in indirect liquid cooling of tractive lithium ion batteries pack. The results show that nanofluids present superior cooling performance to that of pure fluids and the diamond nanofluid presents relatively excellent cooling abilities than that of TiO2 and ZnO nanofluids. During discharge process, the temperature distribution of batteries in batteries pack is uniform and stable, due to steady heat dissipation by indirect liquid cooling. It is expected that nanofluids could be considered as a potential alternative for indirect liquid cooling in electrical vehicles. PMID:26353564

  15. Discrete element method study of fuel relocation and dispersal during loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Govers, K.; Verwerft, M.

    2016-09-01

    The fuel fragmentation, relocation and dispersal (FFRD) during LOCA transients today retain the attention of the nuclear safety community. The fine fragmentation observed at high burnup may, indeed, affect the Emergency Core Cooling System performance: accumulation of fuel debris in the cladding ballooned zone leads to a redistribution of the temperature profile, while dispersal of debris might lead to coolant blockage or to debris circulation through the primary circuit. This work presents a contribution, by discrete element method, towards a mechanistic description of the various stages of FFRD. The fuel fragments are described as a set of interacting particles, behaving as a granular medium. The model shows qualitative and quantitative agreement with experimental observations, such as the packing efficiency in the balloon, which is shown to stabilize at about 55%. The model is then applied to study fuel dispersal, for which experimental parametric studies are both difficult and expensive.

  16. Temperature-Compensated Sapphire Microwave Resonator

    NASA Technical Reports Server (NTRS)

    Dick, G. John; Santiago, David G.

    1996-01-01

    Sapphire-dielectric-ring microwave resonator operating in "whispering-gallery" electromagnetic mode features differential-thermal-expansion design providing temperature compensation for ultrahigh frequency stability. Designed to minimize frequency fluctuations caused by temperature fluctuations at normal temperature equal to or even somewhat greater than temperature of liquid nitrogen. Ancillary equipment needed for operation smaller and less expensive, and liquid nitrogen used as coolant.

  17. Internal cooling of a lithium-ion battery using electrolyte as coolant through microchannels embedded inside the electrodes

    NASA Astrophysics Data System (ADS)

    Mohammadian, Shahabeddin K.; He, Ya-Ling; Zhang, Yuwen

    2015-10-01

    Two and three dimensional transient thermal analysis of a prismatic Li-ion cell has been carried out to compare internal and external cooling methods for thermal management of Lithium Ion (Li-ion) battery packs. Water and liquid electrolyte have been utilized as coolants for external and internal cooling, respectively. The effects of the methods on decreasing the temperature inside the battery and also temperature uniformity were investigated. The results showed that at the same pumping power, using internal cooling not only decreases the bulk temperature inside the battery more than external cooling, but also decreases the standard deviation of the temperature field inside the battery significantly. Finally, using internal cooling decreases the intersection angle between the velocity vector and the temperature gradient which according to field synergy principle (FSP) causes to increase the convection heat transfer.

  18. Cryogenic-coolant He4-superconductor dynamic and static interactions

    NASA Technical Reports Server (NTRS)

    Caspi, S.; Chuang, C.; Kim, Y. I.; Allen, R. J.; Frederking, T. H. E.

    1980-01-01

    A composite superconducting material (NbTi-Cu) was evaluated with emphasis on post quench solid cooling interaction regimes. The quasi-steady runs confirm the existence of a thermodynamic limiting thickness for insulating coatings. Two distinctly different post quench regimes of coated composites are shown to relate to the limiting thickness. Only one regime,, from quench onset to the peak value, revealed favorable coolant states, in particular in He2. Transient recovery shows favorable recovery times from this post quench regime (not drastically different from bare conductors) for both single coated specimens and a coated conductor bundle.

  19. System Study: High-Pressure Coolant Injection 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-01-31

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 25 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  20. System Study: High-Pressure Coolant Injection 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 25 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  1. System Study: High-Pressure Coolant Injection 1998-2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  2. Proposal of New Water Electrode Method Used for Short-time Testing Method of Water Treeing and Consideration on Temperature Effects of Water Tree Initiation and Propagation

    NASA Astrophysics Data System (ADS)

    Uehara, Hiroaki; Kudo, Katsutoshi; Ishikawa, Yoshihiro; Kanekawa, Teruo; Tsuboi, Yuichi; Ushiwata, Kodai; Yoshimitsu, Tetsuo

    Water treeing occurs when ac voltage is applied to electrical insulation system such as those in power cables and power apparatus. From a practical viewpoint, research on water treeing has been mostly performed under high-frequency ac voltage application. However, power cables and power apparatuses are also used under dc voltage application owing to progress in inverter technology. The inverter drive of a rotating electrical machine has spread and expanded for global warming prevention and maintenance improvement. An underwater motor is used in the water. In an underwater motor driven by the voltage of an inverter, it is necessary to consider the water treeing of motor insulation and connected cable insulation with a drive board. Thus far, the water electrode method that utilizes an ac voltage of high frequency has been used in conducting the accelerating experimental method of water treeing for a long time. On the other hand, an inverter with surge voltage generates an equivalent ac frequency by the application of a multifrequency pulse voltage similar to a pulse width modulation (PWM) control wave. Therefore, there is a possibility of committing a mistake in real-machine reliability evaluation because the initiation and propagation mechanisms are different from those in the case of a real-machine even if we can reproduce water treeing by increasing the basic frequency. In this paper, we investigated the new water electrode method and the temperature effects on water tree initiation and propagation. Furthermore, we compared the experimental results between 500Hz and 50Hz by using the new water electrode method from the view point of temperature.

  3. TACT1, a computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 1. Users manual

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1978-01-01

    A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled, axial flow turbine blade or vane with an impingement insert is described. Coolant side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in a chordwise direction and is discharged through the trailing edge and through film cooling holes. The ability of the program to handle film cooling is limited by the internal flow model. Sample problems, with tables of input and output, are included in the report. Input to the program includes a description of the blade geometry, coolant supply conditions, outside thermal boundary conditions, and wheel speed. The blade wall can have two layers of different materials, such as a ceramic thermal barrier coating over a metallic substrate. Program output includes the temperature at each node, the coolant pressures and flow rates, and the inside heat-transfer coefficients.

  4. Analysis of loss-of-coolant accident for a fast-spectrum lithium-cooled nuclear reactor for space-power applications

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Petrik, E. J.; Kieffer, A. W.

    1972-01-01

    A two-dimensional, transient, heat-transfer analysis was made to determine the temperature response in the core of a conceptual space-power nuclear reactor following a total loss of reactor coolant. With loss of coolant from the reactor, the controlling mode of heat transfer is thermal radiation. In one of the schemes considered for removing decay heat from the core, it was assumed that the 4 pi shield which surrounds the core acts as a constant-temperature sink (temperature, 700 K) for absorption of thermal radiation from the core. Results based on this scheme of heat removal show that melting of fuel in the core is possible only when the emissivity of the heat-radiating surfaces in the core is less than about 0.40. In another scheme for removing the afterheat, the core centerline fuel pin was replaced by a redundant, constant temperature, coolant channel. Based on an emissivity of 0.20 for all material surfaces in the core, the calculated maximum fuel temperature for this scheme of heat removal was 2840 K, or about 90 K less than the melting temperature of the UN fuel.

  5. Correlations of norbornenyl crosslinked polyimide resin structures with resin thermo-oxidative stability, resin glass transition temperature and composite initial mechanical properties

    NASA Technical Reports Server (NTRS)

    Alston, William B.

    1988-01-01

    PMR (polymerization of monomeric reactants) methodology was used to prepare 70 different polyimide oligomeric resins and 30 different unidirectional graphite fiber/polyimide composites. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on resin thermo-oxidative stability and glass transition temperature (Tg) of the cured/postcured resins. A linear correlation of decreasing 316 C resin weight loss/surface area versus (1) decreasing aliphatic content, or (2) increasing benzylic/aliphatic content stoichiometry ratio over a wide range of resin compositions was observed. An almost linear correlation of Tg versus molecular distance between the crosslinks was also observed. An attempt was made to correlate Tg with initial composite mechanical properties (flexural strength and interlaminar shear strength). However, the scatter in mechanical strength data prevented obtaining a clear correlation. Instead, only a range of composite mechanical properties was obtained at 25, 288, and 316 C. Perhaps more importantly, what did become apparent during the correlation study was (1) the PMR methodology could be used to prepare composites from resins containing a wide variety of monomer modifications, (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins formulated exhibited satisfactory processing flow, and (3) that PMR resins exhibited predictable rates of 316 C weight loss/surface area based on their benzylic/aliphatic stoichiometery ratio.

  6. Cooperative effects of different temperatures and pressures on the initial and subsequent decomposition reactions of the nitrogen-rich energetic crystal 3,3'-dinitroamino-4,4'-azoxyfurazan.

    PubMed

    Wu, Qiong; Zhu, Weihua; Xiao, Heming

    2016-03-14

    We performed ab initio molecular dynamics simulations to study the initiation mechanisms and subsequent chemical decomposition reactions of the nitrogen-rich furazan explosive 3,3'-dinitroamino-4,4'-azoxyfurazan (DNAAF) at low temperatures (363-963 K) coupled with different pressures (1-5 GPa). Two different initial decomposition mechanisms which are dependent on the temperature and pressure were found: bimolecular intermolecular hydrogen transfer and unimolecular N-NO2 bond breaking. The subsequent decomposition reactions are sensitive to both the temperature and the pressure. The pressure could accelerate or decelerate the decomposition of DNAAF, while the temperature can change the effect of the pressure on the decomposition. Our study may provide new insights into the initial mechanisms and subsequent decomposition of furazan explosives at low temperatures coupled with different pressures in atomic detail. PMID:26882964

  7. Aerodynamic effect of coolant ejection in the rear part of transonic rotor blades

    NASA Astrophysics Data System (ADS)

    Kost, F. H.; Holmes, A. T.

    1985-09-01

    An investigation of transonic turbine blades designed by Rolls-Royce/Bristol concerning the aerodynamic penalties of coolant flow for two alternative cooling configurations is discussed. Rolls-Royce designed a blade with a thick trailing edge where the coolant is ejected through slots in the trailing edge and a second blade with a thin trailing edge where coolant is ejected through a row of holes on the pressure side and a row of holes on the suction side. Tests were performed in a plane cascade wind tunnel. The results indicate the sensitivity of the blade performance to cooling configuration and coolant flow rate. By combining measured data from blade surface and wake traverses it was possible to separate the various loss mechanisms. Therefore, the separate losses due to the momentum of the coolant, change of base pressure, and change of blade friction could be determined quantitatively as a function of coolant flow rate.

  8. Optimization of the water chemistry of the primary coolant at nuclear power plants with VVER

    SciTech Connect

    Barmin, L. F.; Kruglova, T. K.; Sinitsyn, V. P.

    2005-01-15

    Results of the use of automatic hydrogen-content meter for controlling the parameter of 'hydrogen' in the primary coolant circuit of the Kola nuclear power plant are presented. It is shown that the correlation between the 'hydrogen' parameter in the coolant and the 'hydrazine' parameter in the makeup water can be used for controlling the water chemistry of the primary coolant system, which should make it possible to optimize the water chemistry at different power levels.

  9. Chlorine atom-initiated low-temperature oxidation of prenol and isoprenol: The effect of C=C double bonds on the peroxy radical chemistry in alcohol oxidation

    SciTech Connect

    Welz, Oliver; Savee, John D.; Osborn, David L.; Taatjes, Craig A.

    2014-07-04

    The chlorine atom-initiated oxidation of two unsaturated primary C5 alcohols, prenol (3-methyl-2-buten-1-ol, (CH3)2CCHCH2OH) and isoprenol (3-methyl-3-buten-1-ol, CH2C(CH3)CH2CH2OH), is studied at 550 K and low pressure (8 Torr). The time- and isomer-resolved formation of products is probed with multiplexed photoionization mass spectrometry (MPIMS) using tunable vacuum ultraviolet ionizing synchrotron radiation. The peroxy radical chemistry of the unsaturated alcohols appears much less rich than that of saturated C4 and C5 alcohols. The main products observed are the corresponding unsaturated aldehydes – prenal (3-methyl-2-butenal) from prenol oxidation and isoprenal (3-methyl-3-butenal) from isoprenol oxidation. No significant products arising from QOOH chemistry are observed. These results can be qualitatively explained by the formation of resonance stabilized allylic radicals via H-abstraction in the Cl + prenol and Cl + isoprenol initiation reactions. The loss of resonance stabilization upon O2 addition causes the energies of the intermediate wells, saddle points, and products to increase relative to the energy of the initial radicals and O2. These energetic shifts make most product channels observed in the peroxy radical chemistry of saturated alcohols inaccessible for these unsaturated alcohols. The experimental findings are underpinned by quantum-chemical calculations for stationary points on the potential energy surfaces for the reactions of the initial radicals with O2. Under our conditions, the dominant channels in prenol and isoprenol oxidation are the chain-terminating HO2-forming channels arising from radicals, in which the unpaired electron and the –OH group are on the same carbon atom, with stable prenal and isoprenal co-products, respectively. These results suggest that the presence of C=C double bonds in alcohols will reduce

  10. Development of mobile, on-site engine coolant recycling utilizing reverse-osmosis technology

    SciTech Connect

    Kughn, W.; Eaton, E.R.

    1999-08-01

    This paper presents the history of the development of self-contained, mobile, high-volume, engine coolant recycling by reverse osmosis (R/O). It explains the motivations, created by government regulatory agencies, to minimize the liability of waste generators who produce waste engine coolant by providing an engine coolant recycling service at the customer`s location. Recycling the used engine coolant at the point of origin minimizes the generators` exposure to documentation requirements, liability, and financial burdens by greatly reducing the volume of used coolant that must be hauled from the generator`s property. It describes the inherent difficulties of recycling such a highly contaminated, inconsistent input stream, such as used engine coolant, by reverse osmosis. The paper reports how the difficulties were addressed, and documents the state of the art in mobile R/O technology. Reverse osmosis provides a purified intermediate fluid that is reinhibited for use in automotive cooling systems. The paper offers a review of experiences in various automotive applications, including light-duty, medium-duty and heavy-duty vehicles operating on many types of fuel. The authors conclude that mobile embodiments of R/O coolant recycling technology provide finished coolants that perform equivalently to new coolants as demonstrated by their ability to protect vehicles from freezing, corrosion damage, and other cooling system related problems.

  11. Generation of an empirical soil moisture initialization and its potential impact on subseasonal forecasting skill of continental precipitation and air temperature

    NASA Astrophysics Data System (ADS)

    Boisserie, Marie

    The goal of this dissertation research is to produce empirical soil moisture initial conditions (soil moisture analysis) and investigate its impact on the short-term (2 weeks) to subseasonal (2 months) forecasting skill of 2-m air temperature and precipitation. Because of soil moisture has a long memory and plays a role in controlling the surface water and energy budget, an accurate soil moisture analysis is today widely recognized as having the potential to increase summertime climate forecasting skill. However, because of a lack of global observations of soil moisture, there has been no scientific consensus on the importance of the contribution of a soil moisture initialization as close to the truth as possible to climate forecasting skill. In this study, the initial conditions are generated using a Precipitation Assimilation Reanalysis (PAR) technique to produce a soil moisture analysis. This technique consists mainly of nudging precipitation in the atmosphere component of a land-atmosphere model by adjusting the vertical air humidity profile based on the difference between the rate of the model-derived precipitation rate and the observed rate. The unique aspects of the PAR technique are the following: (1) based on the PAR technique, the soil moisture analysis is generated using a coupled land-atmosphere forecast model; therefore, no bias between the initial conditions and the forecast model (spinup problem) is encountered; and (2) the PAR technique is physically consistent; the surface and radiative fluxes remains in conjunction with the soil moisture analysis. To our knowledge, there has been no attempt to use a physically consistent soil moisture land assimilation system into a land-atmosphere model in a coupled mode. The effect of the PAR technique on the model soil moisture estimates is evaluated using the Global Soil Wetness Project Phase 2 (GSWP-2) multimodel analysis product (used as a proxy for global soil moisture observations) and actual in

  12. Hot and deep: Rock record of subduction initiation and exhumation of high-temperature, high-pressure metamorphic rocks, Feather River ultramafic belt, California

    NASA Astrophysics Data System (ADS)

    Smart, Christopher M.; Wakabayashi, John

    2009-12-01

    Studies of a 10 to 300-m-thick unit of high-grade metamorphic rock ("external schists") that crops out along the western border of the Feather River ultramafic belt (FRB), northern California, yield new insights into subduction initiation and ophiolite emplacement processes. The high-temperature ( T) foliation of the external schists dip moderately to steeply eastward beneath the ultramafic rocks of the FRB, a 150-km-long slab of suboceanic upper mantle and the high- T fabric shows a tops-to-the-west (FRB-side-up) sense of shear. The structurally highest external schists record peak metamorphic conditions of 650-760 °C at 1.3-2.2 GPa. In contrast, sheeted dikes of the Devil's Gate ophiolite that overlie the ultramafic rocks yield metamorphic conditions of 710-730 °C at about 0.3-0.7 GPa. A km-scale lens of amphibolite within ultramafic rocks yields somewhat lower pressures than the structurally highest external schist, as do the structurally lower rocks within the external schists. Significant exhumation of the external schists relative to the structurally overlying ophiolitic rocks occurred along at least two major zones and the most significant exhumation was accommodated at least 1.5 km structurally above the ultramafic-external schist contact. Based on available geochronology, intraoceanic subduction may have initiated at approximately 240 Ma, and exposure of the external schist occurred prior to the deposition of rocks in the structurally highest part of the Calaveras Complex (minimum 177 Ma), a subduction complex that structurally underlies the external schists. High- T metamorphism of the Devil's Gate ophiolite may have resulted from partial (failed) ridge subduction.

  13. Low Temperature Chlorine-Initiated Oxidation of Small-Chain Methyl Esters: Quantification of Chain-Terminating HO2-Elimination Channels.

    PubMed

    Muller, Giel; Scheer, Adam; Osborn, David L; Taatjes, Craig A; Meloni, Giovanni

    2016-03-17

    Cl-initiated oxidation reactions of three small-chain methyl esters, methyl propanoate (CH3CH2COOCH3; MP), methyl butanoate (CH3CH2CH2COOCH3; MB), and methyl valerate (CH3CH2CH2CH2COOCH3; MV), are studied at 1 or 8 Torr and 550 and 650 K. Products are monitored as a function of mass, time, and photoionization energy using multiplexed photoionization mass spectrometry coupled to tunable synchrotron photoionization radiation. Pulsed photolysis of molecular chlorine is the source of Cl radicals, which remove an H atom from the ester, forming a free radical. In each case, after addition of O2 to the initial radicals, chain-terminating HO2-elimination reactions are observed to be important. Branching ratios among competing HO2-elimination channels are determined via absolute photoionization spectra of the unsaturated methyl ester coproducts. At 550 K, HO2-elimination is observed to be selective, resulting in nearly exclusive production of the conjugated methyl ester coproducts, methyl propenoate, methyl-2-butenoate, and methyl-2-pentenoate, respectively. However, in MV, upon raising the temperature to 650 K, other HO2-elimination pathways are observed that yield methyl-3-pentenoate and methyl-4-pentenoate. In each methyl ester oxidation reaction, a peak is observed at a mass consistent with cyclic ether formation, indicating chain-propagating OH loss/ring formation pathways via QOOH intermediates. Evidence is observed for the participation of resonance-stabilized QOOH in the most prominent cyclic ether pathways. Stationary point energies for HO2-elimination pathways and select cyclic ether formation channels are calculated at the CBS-QB3 level of theory and assist in the assignment of reaction pathways and final products. PMID:26910881

  14. Sensitivity studies of loss-of-coolant accidents in the Savannah River production reactors

    SciTech Connect

    Edwards, J.N.; Motley, F.E.; Morgan, M.M.; Knight, T.D.; Fischer, S.R. )

    1990-01-01

    Loss-of-coolant accident (LOCA) analyses were completed using the Transient Reactor Analysis Code (TRAC) to support the U.S. Department of Energy efforts to restart the production reactors located at the Savannah River Site. The break location and pump operation after the LOCA were the parameters varied for these sensitivity studies. Three location of double-ended guillotine break were studied: plenum inlet, pump suction, and pump discharge. Three pump operation scenarios were also studied: continued operation of both ac and dc pumps, tripping of the ac motor at 2 s after the LOCA, and tripping of the ac motor at 200 s after the LOCA. The production reactors use low pressure and temperature heavy water as the process fluid. The reactor has a moderator tank that contains the fuel channels. Above the moderator tank is an upper plenum that distributes the heavy water to each fuel assembly. The heavy water flows down through the fuel channels and into the moderator tank. From the tank, the water is pumped back to the upper plenum through six loops. Each loop contains a pump and two heat exchangers. Four of the loops have an emergency core coolant system (ECCS) connection. This TRAC model has been benchmarked extensively against data taken in the actual reactors or in prototypical models of the components of the reactors. The calculations were completed using a version of TRAC-PF1/MOD 2 that was updated to include heavy water properties and other changes that are specific to the production reactors.

  15. Scaling and design analyses of a scaled-down, high-temperature test facility for experimental investigation of the initial stages of a VHTR air-ingress accident

    SciTech Connect

    Arcilesi, David J.; Ham, Tae Kyu; Kim, In Hun; Sun, Xiaodong; Christensen, Richard N.; Oh, Chang H.

    2015-07-01

    A critical event in the safety analysis of the very high-temperature gas-cooled reactor (VHTR) is an air-ingress accident. This accident is initiated, in its worst case scenario, by a double-ended guillotine break of the coaxial cross vessel, which leads to a rapid reactor vessel depressurization. In a VHTR, the reactor vessel is located within a reactor cavity that is filled with air during normal operating conditions. Following the vessel depressurization, the dominant mode of ingress of an air–helium mixture into the reactor vessel will either be molecular diffusion or density-driven stratified flow. The mode of ingress is hypothesized to depend largely on the break conditions of the cross vessel. Since the time scales of these two ingress phenomena differ by orders of magnitude, it is imperative to understand under which conditions each of these mechanisms will dominate in the air ingress process. Computer models have been developed to analyze this type of accident scenario. There are, however, limited experimental data available to understand the phenomenology of the air-ingress accident and to validate these models. Therefore, there is a need to design and construct a scaled-down experimental test facility to simulate the air-ingress accident scenarios and to collect experimental data. The current paper focuses on the analyses performed for the design and operation of a 1/8th geometric scale (by height and diameter), high-temperature test facility. A geometric scaling analysis for the VHTR, a time scale analysis of the air-ingress phenomenon, a transient depressurization analysis of the reactor vessel, a hydraulic similarity analysis of the test facility, a heat transfer characterization of the hot plenum, a power scaling analysis for the reactor system, and a design analysis of the containment vessel are discussed.

  16. Temperature dependence of the yields of methacrolein and methyl vinyl ketone from the OH-initiated oxidation of isoprene under NOx free conditions

    NASA Astrophysics Data System (ADS)

    Navarro, M. A.; Dusanter, S.; Stevens, P. S.; Hites, R. A.

    2010-12-01

    Isoprene, the dominant biogenic hydrocarbon emitted into the atmosphere by deciduous trees, can contribute significantly to the production of tropospheric ozone and secondary organic aerosols due to its high reactivity with oxidants. It is therefore important to correctly describe its oxidation chemistry in models of atmospheric chemistry. However, recent measurements of HOx (OH + HO2) radicals in forest environments show serious discrepancies with modeled concentrations, bringing into question our understanding of the atmospheric chemistry of isoprene and other reactive biogenic compounds. A previous study conducted in our group on the OH-initiated oxidation of isoprene under NOx free conditions indicated that the yields of methacrolein (MAC) and methyl vinyl ketone (MVK) are dependent on the ratio of HO2-to-isoprene-based peroxy radicals (ISORO2). It is likely due to a competition between ISORO2 self- and cross-reactions that leads to the formation of the primary products, with reactions between these peroxy radicals and HO2 which can lead to the formation of peroxides. This presentation will expand the scope of the abovementioned study by investigating the temperature dependence of the yields of MAC and MVK in the range 30-70°C. We will present results from experiments conducted using a small UV-irradiated reaction chamber coupled to an on-line mass spectrometer. In addition, we will compare the measured yields to that predicted by the Master Chemical Mechanism (MCM), including recently proposed radical recycling reactions, to determine whether current models of atmospheric chemistry provide a complete description for the formation of these primary products as a function of temperature.

  17. Zero waste machine coolant management strategy at Los Alamos National Laboratory

    SciTech Connect

    Carlson, B.; Algarra, F.; Wilburn, D.

    1998-12-01

    Machine coolants are used in machining equipment including lathes, grinders, saws and drills. The purpose of coolants is to wash away machinery debris in the form of metal fines, lubricate, and disperse heat between the part and the machine tool. An effective coolant prolongs tool life and protects against part rejection, commonly due to scoring or scorching. Traditionally, coolants have a very short effective life in the machine, often times being disposed of as frequently as once per week. The cause of coolant degradation is primarily due to the effects of bacteria, which thrive in the organic rich coolant environment. Bacteria in this environment reproduce at a logarithmic rate, destroying the coolant desirable aspects and causing potential worker health risks associated with the use of biocides to control the bacteria. The strategy described in this paper has effectively controlled bacterial activity without the use of biocides, avoided disposal of a hazardous waste, and has extend ed coolant life indefinitely. The Machine Coolant Management Strategy employed a combination of filtration, heavy lubricating oil removal, and aeration, which maintained the coolant peak performance without the use of biocides. In FY96, the Laboratory generated and disposed of 19,880 kg of coolants from 9 separate sites at a cost of $145K. The single largest generator was the main machine shop producing an average 14,000 kg annually. However, in FY97, the waste generation for the main machine shop dropped to 4,000 kg after the implementation of the zero waste strategy. It is expected that this value will be further reduced in FY98.

  18. Zero Waste Machine Coolant Management Strategy at Los Alamos National Laboratory

    SciTech Connect

    Carlson, B.; Algarra, F.; Wilburn, D.

    1998-06-01

    Machine coolants are used in machining equipment including lathes, grinders, saws and drills. The purpose of coolants is to wash away machinery debris in the form of metal fines, lubricate, and disperse heat between the part and the machine tool. An effective coolant prolongs tool life and protects against part rejection, commonly due to scoring or scorching. Traditionally, coolants have a very short effective life in the machine, often times being disposed of as frequently as once per week. The cause of coolant degradation is primarily due to the effects of bacteria, which thrive in the organic rich coolant environment. Bacteria in this environment reproduce at a logarithmic rate, destroying the coolant desirable aspects and causing potential worker health risks associated with the use of biocides to control the bacteria. The strategy described in this paper has effectively controlled bacterial activity without the use of biocides, avoided disposal of a hazardous waste, and has extend ed coolant life indefinitely. The Machine Coolant Management Strategy employed a combination of filtration, heavy lubricating oil removal, and aeration, which maintained the coolant peak performance without the use of biocides. In FY96, the Laboratory generated and disposed of 19,880 kg of coolants from 9 separate sites at a cost of $145K. The single largest generator was the main machine shop producing an average 14,000 kg annually. However, in FY97, the waste generation for the main machine shop dropped to 4,000 kg after the implementation of the zero waste strategy. It is expected that this value will be further reduced in FY98.

  19. Robotic inspection of PWR coolant pump casing welds

    SciTech Connect

    Pratt, W.R.; Alford, J.W.; Davis, J.B.

    1997-12-01

    As of January 1, 1995, the Swedish Nuclear Inspectorate began requiring more thorough inspections of cast stainless-steel components in nuclear power plants, including pressurized water reactor (PWR) reactor coolant pump (RCP) casings. The examination requirements are established by fracture mechanics analyses of component weldments and demonstrated test system detection capabilities. This may include full volumetric inspection or some portion thereof. Ringhals station is a four-unit nuclear power plant, owned and operated by the Swedish State Power Board, Vattenfall. Unit 1 is a boiling water reactor. Units 2, 3, and 4 are Westinghouse-designed PWRs, ranging in size from 795 to 925 MW. The RCP casings at the PWR units are made of cast stainless steel and contain four circumferential welds that require inspection. Due to the thickness of the casings at the weld locations and configuration and surface conditions on the outside diameter of the casings, remote inspection from the inside diameter of the pump casing was mandated.

  20. Actively controlling coolant-cooled cold plate configuration

    DOEpatents

    Chainer, Timothy J.; Parida, Pritish R.

    2016-04-26

    Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.

  1. Leak rate analysis of the Westinghouse Reactor Coolant Pump

    SciTech Connect

    Boardman, T.; Jeanmougin, N.; Lofaro, R.; Prevost, J.

    1985-07-01

    An independent analysis was performed by ETEC to determine what the seal leakage rates would be for the Westinghouse Reactor Coolant Pump (RCP) during a postulated station blackout resulting from loss of ac electric power. The object of the study was to determine leakage rates for the following conditions: Case 1: All three seals function. Case 2: No. 1 seal fails open while Nos. 2 and 3 seals function. Case 3: All three seals fail open. The ETEC analysis confirmed Westinghouse calculations on RCP seal performance for the conditions investigated. The leak rates predicted by ETEC were slightly lower than those predicted by Westinghouse for each of the three cases as summarized below. Case 1: ETEC predicted 19.6 gpm, Westinghouse predicted 21.1 gpm. Case 2: ETEC predicted 64.7 gpm, Westinghouse predicted 75.6 gpm. Case 3: ETEC predicted 422 gpm, Westinghouse predicted 480 gpm. 3 refs., 22 figs., 6 tabs.

  2. Loss of coolant analysis for the tower shielding reactor 2

    SciTech Connect

    Radcliff, T.D.; Williams, P.T.

    1990-06-01

    The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs.

  3. Fusion Blanket Coolant Section Criteria, Methodology, and Results

    SciTech Connect

    DeMuth, J. A.; Meier, W. R.; Jolodosky, A.; Frantoni, M.; Reyes, S.

    2015-10-02

    The focus of this LDRD was to explore potential Li alloys that would meet the tritium breeding and blanket cooling requirements but with reduced chemical reactivity, while maintaining the other attractive features of pure Li breeder/coolant. In other fusion approaches (magnetic fusion energy or MFE), 17Li- 83Pb alloy is used leveraging Pb’s ability to maintain high TBR while lowering the levels of lithium in the system. Unfortunately this alloy has a number of potential draw-backs. Due to the high Pb content, this alloy suffers from very high average density, low tritium solubility, low system energy, and produces undesirable activation products in particular polonium. The criteria considered in the selection of a tritium breeding alloy are described in the following section.

  4. Electrochemical pitting evaluation of aluminium alloy 7075 in machining coolant

    SciTech Connect

    Stanaland, V.A.; Dillon, J.J.

    1984-08-24

    The corrosion rate of aluminum alloy 7075 in Trim Sol with a Tris-Nitro biocide addition is satisfactory. Both deaeration and increasing the nitrite addition decreased the stability of the passive film. Chloride contamination below 500 ppM does not cause pitting corrosion of aluminum alloy 7075 in the Trim Sol environment. The limit for chloride contamination is between 500 and 1000 ppM. The potentiodynamic, fast-scan-rate technique is satisfactory for evaluating the pitting tendency of the aluminum alloy 7075 in a Trim Sol environment. Consequently, the potentiodynamic, fast-scan-rate technique is recommended for use in conjunction with reverse scans to evaluate the quality of in-use machining coolants, that are suspected of causing contamination.

  5. The aerodynamic effects of wheelspace coolant injection into the mainstream flow of a high pressure gas turbine

    NASA Astrophysics Data System (ADS)

    McLean, Christopher Elliot

    Modern gas turbine engines operate with mainstream gas temperatures exceeding 1450°C in the high-pressure turbine stage. Unlike turbine blades, rotor disks and other internal components are not designed to withstand the extreme temperatures found in mainstream flow. In modern gas turbines, cooling air is pumped into the wheelspace cavities to prevent mainstream gas ingestion and then exits through a seal between the rotor and the nozzle guide vane (NGV) thereby mixing with the mainstream flow. The primary purpose for the wheelspace cooling air is the cooling of the turbine wheelspace. However, secondary effects arise from the mixing of the spent cooling air with the mainstream flow. The exiting cooling air is mixed with the hot mainstream flow effecting the aerodynamic and performance characteristics of the turbine stage. The physics underlying this mixing process and its effects on stage performance are not yet fully understood. The relative aerodynamic and performance effects associated with rotor - NGV gap coolant injections were investigated in the Axial Flow Turbine Research Facility (AFTRF) of the Center for Gas Turbines and Power of The Pennsylvania State University. This study quantifies the secondary effects of the coolant injection on the aerodynamic and performance character of the turbines main stream flow for root injection, radial cooling, and impingement cooling. Measurement and analysis of the cooling effects were performed in both stationary and rotational frames of reference. The AFTRF is unique in its ability to perform long duration cooling measurements in the stationary and rotating frames. The effects of wheelspace coolant mixing with the mainstream flow on total-to-total efficiency, energy transport, three dimensional velocity field, and loading coefficient were investigated. Overall, it was found that a small quantity (1%) of cooling air can have significant effects on the performance character and exit conditions of the high pressure stage

  6. Enhanced production of direct photons in Au + Au collisions at square root(S(NN)) = 200 GeV and implications for the initial temperature.

    PubMed

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Al-Jamel, A; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bickley, A A; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chang, B S; Charvet, J-L; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Das, K; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Eyser, K O; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Forestier, B; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fung, S-Y; Fusayasu, T; Gadrat, S; Garishvili, I; Gastineau, F; Germain, M; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-A; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hagiwara, M N; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; Heuser, J M; He, X; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hur, M G; Ichihara, T; Imai, K; Inaba, M; Inoue, Y; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Kawagishi, T; Kawall, D; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kroon, P J; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y-S; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Lim, H; Liska, T; Litvinenko, A; Liu, M X; Li, X; Li, X H; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mao, Y; Masek, L; Masui, H; Matathias, F; McCain, M C; McCumber, M; McGaughey, P L; Miake, Y; Mikes, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mishra, M; Mitchell, J T; Mitrovski, M; Morreale, A; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Norman, B E; Nyanin, A S; Nystrand, J; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, H; Okada, K; Oka, M; Omiwade, O O; Oskarsson, A; Otterlund, I; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakata, H; Samsonov, V; Sato, H D; Sato, S; Sawada, S; Seele, J; Seidl, R; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Slunecka, M; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Thomas, T L; Togawa, M; Toia, A; Tojo, J; Tomásek, L; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tuli, S K; Tydesjö, H; Tyurin, N; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vertesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zimányi, J; Zolin, L

    2010-04-01

    The production of e+ e- pairs for m(e+ e-)<0.3 GeV/c2 and 1initial temperatures ranging from T(init) approximately 300-600 MeV at times of approximately 0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at approximately 170 MeV. PMID:20481877

  7. Enhanced Production of Direct Photons in Au+Au Collisions at {radical}(s{sub NN})=200 GeV and Implications for the Initial Temperature

    SciTech Connect

    Adare, A.; Bickley, A. A.; Ellinghaus, F.; Kelly, S.; Kinney, E.; Nagle, J. L.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Bjorndal, M. T.; Chi, C. Y.; Cole, B. A.; D'Enterria, D.

    2010-04-02

    The production of e{sup +}e{sup -} pairs for m{sub e}{sup +}{sub e}{sup -}<0.3 GeV/c{sup 2} and 1initial temperatures ranging from T{sub init{approx}}300-600 MeV at times of {approx}0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at {approx}170 MeV.

  8. Performance of the Extravehicular Mobility Unit (EMU): Airlock Coolant Loop Recovery (A/L CLR) Hardware - Phase II

    NASA Technical Reports Server (NTRS)

    Steele, John; Rector, tony; Gazda, Daniel; Lewis, John

    2009-01-01

    An EMU water processing kit (Airlock Coolant Loop Recovery A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. Conservative schedules for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. The examination of postflight samples and EMU hardware in November of 2006 indicated that the A/L CLR kits were functioning well and had excess capacity that would allow a relaxation of the initially conservative schedules of use and component life. A relaxed use schedule and list of component lives was implemented thereafter. Since the adoption of the relaxed A/L CLR schedules of use and component lives, several A/L CLR kit components, transport loop water samples and sensitive EMU transport loop components have been examined to gage the impact of the relaxed requirements. The intent of this paper is to summarize the findings of that evaluation, and to outline updated schedules for A/L CLR use and component life.

  9. Investigation of an anion exchange resin for cleanup of a coolant used to machine nuclear materials

    SciTech Connect

    Hinton, E.R. Jr.; Tucker, H.L.; Asbury, W.L.

    1986-01-01

    This article describes the interaction of Dowex SBR-P, which is a strongly basic anion exchange resin, with ions found in a used machining coolant. The coolant is used in machining enriched uranium and contains uranium, chloride, nitrite, borate ions, water, and propylene glycol.

  10. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Acceptance criteria for reactor coolant system venting systems. 50.46a Section 50.46a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Standards for Licenses, Certifications, and Regulatory Approvals § 50.46a Acceptance criteria for reactor coolant...

  11. Using automatic particle counting to monitor aluminum cold mill coolant{copyright}

    SciTech Connect

    Adkins, D.L.

    1995-08-01

    A comprehensive program of testing and evaluation of aluminum cold rolling coolant conditions has been conducted using an automatic particle counting instrument. The project had three objectives. First, there was a need to know at what level of coolant particle contamination is surface cleanliness of an aluminum sheet affected during the rolling process. Secondly, is application of particle counting technology a reliable tool for troubleshooting coolant filtration systems and finally, what are the advantages of analyzing rolling coolants for contamination levels? A testing program was designed and performed over a two-year period. The test results revealed that mineral seal and synthetic-type coolants can begin to affect aluminum sheet surface cleanliness levels when particle sizes greater than five microns are in excess of 10,000 particles power 100 milliliters of rolling coolant. After performing over 3,000 separate tests, it was very clean that particle count levels are direct indicators of how well a filtration facility is performing. Through the application of particle counting, a number of conditions in coolant filtration facilities can be readily detected. Such items as defective filter valving, torn or fractured filter cloth, damaged filter parts, improper equipment operation and many other factors will directly impact the operation of aluminum cold rolling coolant filters. 11 figs.

  12. Some peculiarities of checking the Topaz-2 system coolant filling quality

    SciTech Connect

    Ogloblin, B.G.; Svishchev, A.M.; Shalaev, A.I.

    1996-03-01

    This paper contains the analysis of validity of methods used for checking the Topaz-2 system coolant filling quality by a metering tank according to the mathematical model developed. A number of criteria is proposed for detecting occluded gas in the coolant loop. {copyright} {ital 1996 American Institute of Physics.}

  13. Coolant flows in prismatic fuel and particle bed nuclear reactors for rocket applications

    NASA Astrophysics Data System (ADS)

    Bohachevsky, Ihor O.

    1993-01-01

    Semiempirical expressions for pressure losses in prismatic and particle bed reactors for nuclear propulsion are combined with the geometric characteristics of core configurations and coolant flow patterns. The results are used to illustrate a limitation on the coolant velocity and to develop a unified approach to a quantitative comparison of merits and demerits of different reactor core concepts intended for space applications.

  14. Blade-to-coolant heat-transfer results and operating data from a natural-convection water-cooled single-stage turbine

    NASA Technical Reports Server (NTRS)

    Diaguila, Anthony J; Freche, John C

    1951-01-01

    Blade-to-coolant heat-transfer data and operating data were obtained with a natural-convection water-cooled turbine over range of turbine speeds and inlet-gas temperatures. The convective coefficients were correlated by the general relation for natural-convection heat transfer. The turbine data were displaced from a theoretical equation for natural convection heat transfer in the turbulent region and from natural-convection data obtained with vertical cylinders and plates; possible disruption of natural convection circulation within the blade coolant passages was thus indicated. Comparison of non dimensional temperature-ratio parameters for the blade leading edge, midchord, and trailing edge indicated that the blade cooling effectiveness is greatest at the midchord and least at the trailing edge.

  15. Investigations of ice formation in the Space Shuttle Main Engine 0209 main injector coolant cavity

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Charklwick, D. M.

    1991-01-01

    Severe main combustion chamber wall and main injector baffle element deterioration occurred during tests of Space Shuttle Main Engine 0209. One of the possible causes considered is ice formation and blockage of coolant to these components, resulting from the mixing of leaking hot turbine exhaust gas (hydrogen rich steam) and hydrogen coolant in the injector coolant cavity. The plausibility of ice blockage is investigated through simple mixing calculations for hot gas and hydrogen, investigation of condensation and water droplet formation, calculation of the freezing times for droplets, and the prediction of ice layer thicknesses. It is concluded that condensation and droplet formation can occur, and small water droplets that form can freeze very quickly when in contact with the cold coolant cavity surfaces. Copnservative analysis predicts, however, that the maximum thickness of the ice layers formed is too small to result in significant blockage of the coolant flow.

  16. Electrochemical behaviour of stainless steel in PWR primary coolant conditions: Effects of radiolysis

    NASA Astrophysics Data System (ADS)

    Muzeau, Benoist; Perrin, Stéphane; Corbel, Catherine; Simon, Dominique; Feron, Damien

    2011-12-01

    Few data are available in the literature on the role of the water radiolysis on the corrosion of stainless steel core components in PWR operating conditions (300 °C, 155 bar). The present approach uses a high energy proton beam to control the production of radiolytic species at the interface between a stainless steel sample and water in a high temperature and high pressure (HP-HT) electrochemical cell working in the range 25 °C/1 bar-300 °C/90 bar. The cell is designed to record the free corrosion potential of the AISI 316L/water interface mounted in line with a cyclotron delivering the proton beam. The evolution of the potential is compared before, during and after the proton irradiation. The first results are obtained with an aqueous solution containing boron, lithium and dissolved hydrogen, as in PWR primary coolant circuit. The stainless steel/water interfaces are irradiated between 25 °C and 300 °C with protons emerging at 22 MeV at the interface. The flux is varied by five orders of magnitude, from 6.6 × 10 11 to 6.6 × 10 15 H + m -2 s -1. The evolution of the free corrosion potential is highly dependent on the temperature and/or pressure. For a given temperature and pressure, it evolves with the flux and the ageing of the AISI 316L/water interfaces. An important role of the temperature of irradiation on the electrochemical response was observed. These results give a better understanding of the role of radiolysis on stainless steel corrosion in high temperature conditions.

  17. Characterization of uranium surfaces machined with aqueous propylene glycol-borax or perchloroethylene-mineral oil coolants

    SciTech Connect

    Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.; Richards, H.L.; Seals, R.D.; Byrd, V.R.

    1986-12-31

    The use of perchloroethylene (perc) as an ingredient in coolants for machining enriched uranium at the Oak Ridge Y-12 Plant has been discontinued because of environmental concerns. A new coolant was substituted in December 1985, which consists of an aqueous solution of propylene glycol with borax (sodium tetraborate) added as a nuclear poison and with a nitrite added as a corrosion inhibitor. Uranium surfaces machined using the two coolants were compared with respects to residual contamination, corrosion or corrosion potential, and with the aqueous propylene glycol-borax coolant was found to be better than that of enriched uranium machined with the perc-mineral oil coolant. The boron residues on the final-finished parts machined with the borax-containing coolant were not sufficient to cause problems in further processing. All evidence indicated that the enriched uranium surfaces machined with the borax-containing coolant will be as satisfactory as those machined with the perc coolant.

  18. Simulating experimental investigation on the safety of nuclear heating reactor in loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Xu, Zhanjie

    1996-12-01

    The 5MW low temperature nuclear heating reactor (NHR-5) is a new and advanced type of nuclear reactor developed by Institute of Nuclear Energy Technology (INET) of Tsinghua University of China in 1989. Its main loop is a thermal-hydraulic system with natural circulation. This paper studies the safety of NHR under the condition of loss-of-coolant accidents (LOCAs) by means of simulant experiments. First, the background and necessity of the experiments are presented, then the experimental system, including the thermal-hydraulic system and the data collection system, and similarity criteria are introduced. Up to now, the discharge experiments with the residual heating power (20% rated heating power) have been carried out on the experimental system. The system parameters including circulation flow rate, system pressure, system temperature, void fraction, discharge mass and so on have been recorded and analyzed. Based on the results of the experiments, the conclusions are shown as follos: on the whole, the reactor is safe under the condition of LOCAs, but the thermal vacillations resulting from the vibration of the circulation flow rate are disadvantageous to the internal parts of the reactor core.

  19. Excited Oxidized-Carbon Nanodots Induced by Ozone from Low-Temperature Plasma to Initiate Strong Chemiluminescence for Fast Discrimination of Metal Ions.

    PubMed

    Long, Zi; Fang, De-Cai; Ren, Hong; Ouyang, Jin; He, Lixin; Na, Na

    2016-08-01

    Carbon nanodots (C-dots) are recently well examined due to the emissions with color-tuning and nonblinking properties, while more studies are still needed for the appropriate understanding and application of distinct emissions. In this work, we found the emission of chemiluminescence (CL) by introducing low-temperature plasma (LTP) into C-dots solutions without any reagent added, whose intensity was affected by the presence of different metal ions. Based on both experimental data and theoretical calculations, we found with the ozonation by ozone from LTP, excited oxidized-C-dots would be generated with the addition of ozone onto the conjugated double bonds of C-dots, and these excited species could directly initiate strong CL combining with the deactivation of excited species to the ground state. Significantly, the cross-reactive CL signals were obtained from different kinds of C-dots with the presence of different metal ions. Therefore, a new sensor array (electronic tongue) composed of five different C-dots was designed for fast discrimination of metal ions, which achieved the accurate discrimination of 13 kinds of metal ions in pure water and real samples. It exhibited good reproducibility and sensitivity, which can be used for the quantitative analysis of metal ions such as showing a linear range from 4 × 10(-7) to 6 × 10(-5) mol·L(-1) (R(2) > 0.99) for Fe(3+) with a detection limit of 2.5 × 10(-7) mol·L(-1). This work not only provides a novel finding of CL from C-dots revealing explicit relationship between structures and CL properties, but also realizes the fast discrimination of metal ions, showing potentials in environmental monitoring and quality identifications. PMID:27376407

  20. Facility Configuration Study of the High Temperature Gas-Cooled Reactor Component Test Facility

    SciTech Connect

    S. L. Austad; L. E. Guillen; D. S. Ferguson; B. L. Blakely; D. M. Pace; D. Lopez; J. D. Zolynski; B. L. Cowley; V. J. Balls; E.A. Harvego, P.E.; C.W. McKnight, P.E.; R.S. Stewart; B.D. Christensen

    2008-04-01

    A test facility, referred to as the High Temperature Gas-Cooled Reactor Component Test Facility or CTF, will be sited at Idaho National Laboratory for the purposes of supporting development of high temperature gas thermal-hydraulic technologies (helium, helium-Nitrogen, CO2, etc.) as applied in heat transport and heat transfer applications in High Temperature Gas-Cooled Reactors. Such applications include, but are not limited to: primary coolant; secondary coolant; intermediate, secondary, and tertiary heat transfer; and demonstration of processes requiring high temperatures such as hydrogen production. The facility will initially support completion of the Next Generation Nuclear Plant. It will secondarily be open for use by the full range of suppliers, end-users, facilitators, government laboratories, and others in the domestic and international community supporting the development and application of High Temperature Gas-Cooled Reactor technology. This pre-conceptual facility configuration study, which forms the basis for a cost estimate to support CTF scoping and planning, accomplishes the following objectives: • Identifies pre-conceptual design requirements • Develops test loop equipment schematics and layout • Identifies space allocations for each of the facility functions, as required • Develops a pre-conceptual site layout including transportation, parking and support structures, and railway systems • Identifies pre-conceptual utility and support system needs • Establishes pre-conceptual electrical one-line drawings and schedule for development of power needs.

  1. Flow in serpentine coolant passages with trip strips

    NASA Technical Reports Server (NTRS)

    Tse, D. G.-N.

    1995-01-01

    Under the subject contract, an effort is being conducted at Scientific Research Associates, Inc. (SRA) to obtain flow field measurements in the coolant passage of a rotating turbine blade with ribbed walls, both in the stationary and rotating frames. The data obtained will be used for validation of computational tools and assessment of turbine blade cooling strategies. The configuration of the turbine blade passage model is given, and the measuring plane locations are given. The model has a four-pass passage with three 180 turns. This geometry was chosen to allow analyses of the velocity measurements corresponding to the heat transfer results obtained by Wagner. Two passes of the passage have a rectangular cross-section of 1.0 in x 0.5 in. Another two passes have a square cross-section of 0.5 in x 0.5 in. Trips with a streamwise pitch to trip height (P/e) = 5 and trip height to coolant passage width (e/Z) = 0.1, were machined along the leading and trailing walls. These dimensions are typical of those used in turbine blade coolant passages. The trips on these walls are staggered by the half-pitch. The trips are skewed at +/- 45 deg, and this allows the effect of trip orientation to be examined. Experiments will be conducted with flow entering the model through the 1.0 in x 0.5 in rectangular passage (Configuration C) and the 0.5 in x 0. 5 in square passage (Configuration D) to examine the effect of passage aspect ratio. Velocity measurements were obtained with a Reynolds number (Re) of 25,000, based on the hydraulic diameter of and bulk mean velocity in the half inch square passage. The coordinate system used in presenting the results for configurations C and D, respectively, is shown. The first, second and third passes of the passage will be referred to as the first, second and third passages, respectively, in later discussion. Streamwise distance (x) from the entrance is normalized by the hydraulic diameter (D). Vertical (y) and tangential (z) distances are

  2. Temperature-time distribution and thermal stresses on the RTG fins and shell during water cooling

    NASA Technical Reports Server (NTRS)

    Turner, R. H.

    1983-01-01

    Radioisotope thermoelectric generator (RTG) packages designed for space missions generally do not require active cooling. However, the heat they generate cannot remain inside of the launch vehicle bay and requires active removal. Therefore, before the Shuttle bay door is closed, the RTG coolant tubes attached to the heat rejection fins must be filled with water, which will circulate and remove most of the heat from the cargo bay. There is concern that charging a system at initial temperature around 200 C with water at 24 C can cause unacceptable thermal stresses in the RTG shell and fins. A computer model is developed to estimate the transient temperature distribution resulting from such charging. The thermal stresses resulting from the temperature gradients do not exceed the elastic deformation limit for the material. Since the simplified mathematical model for thermal stresses tends to overestimate stresses, it is concluded that the RTG can be cooled by introducing water at 24 C to the initially hot fin coolant tubes while the RTG is in the Shuttle cargo bay.

  3. Radiogenic lead with dominant content of {sup 208}Pb: New coolant and neutron moderator for innovative nuclear reactors

    SciTech Connect

    Shmelev, A. N.; Kulikov, G. G.; Kryuchkov, E. F.; Apse, V. A.; Kulikov, E. G.

    2012-07-01

    The advantages of radiogenic lead with dominant content of {sup 208}Pb as a reactor coolant with respect to natural lead are caused by unique nuclear properties of {sup 208}Pb which is a double-magic nucleus with closed proton and neutron shells. This results in significantly lower micro cross section and resonance integral of radiative neutron capture by {sup 208}Pb than those for numerous light neutron moderators. The extremely weak ability of {sup 208}Pb to absorb neutrons results in the following effects. Firstly, neutron moderating factor (ratio of scattering to capture cross sections) is larger than that for graphite and light water. Secondly, age and diffusion length of thermal neutrons are larger than those for graphite, light and heavy water. Thirdly, neutron lifetime in {sup 208}Pb is comparable with that for graphite, beryllium and heavy water what could be important for safe reactor operation. The paper presents some results obtained in neutronics and thermal-hydraulics evaluations of the benefits from the use of radiogenic lead with dominant content of {sup 208}Pb instead of natural lead as a coolant of fast breeder reactors. The paper demonstrates that substitution of radiogenic lead for natural lead can offer the following benefits for operation of fast breeder reactors. Firstly, improvement of the reactor safety thanks to the better values of coolant temperature reactivity coefficient and, secondly, improvement of some thermal-hydraulic reactor parameters. Radiogenic lead can be extracted from thorium sludge without isotope separation as {sup 208}Pb is a final isotope in the decay chain of {sup 232}Th. (authors)

  4. Polymer electrolyte membrane fuel cell performance degradation by coolant leakage and recovery

    NASA Astrophysics Data System (ADS)

    Jung, Ju Hae; Kim, Se Hoon; Hur, Seung Hyun; Joo, Sang Hoon; Choi, Won Mook; Kim, Junbom

    2013-03-01

    Coolant leakage leads to decrease in performance during the operation of electric vehicles which make use of polymer electrolyte membrane fuel cells (PEMFC). This study examines the effects of various coolant leak conditions in 3-cell stack and single cell. The experimental results show that an irreversible reduction in performance occurs after coolant injection into the anode side of the stack. Poisoning of carbon monoxide (CO) on the platinum (Pt) catalyst is caused by electro-oxidation reaction of EG. Water cleaning is selected because CO poisoning is desorbed to reaction with water molecules. Performance is quickly reduced when the interval between coolant injections is short. Performance reduction is indicated by the experimental results for the gas diffusion layer (GDL) and the membrane electrode assembly (MEA). It shows that performance of the MEA with the GDL exposed to coolant decreased, but it is recovered after water cleaning. In contrast, results for performance of the MEA exposed to coolant for long time could not be reversed after water cleaning. Therefore, we propose that performance degradation of coolant leak on the Pt catalyst surface and GDL can be recovered by the water cleaning simply without disassembly of stack.

  5. Integrity of the reactor coolant boundary of the European pressurized water reactor (EPR)

    SciTech Connect

    Goetsch, D.; Bieniussa, K.; Schulz, H.; Jalouneix, J.

    1997-04-01

    This paper is an abstract of the work performed in the frame of the development of the IPSN/GRS approach in view of the EPR conceptual safety features. EPR is a pressurized water reactor which will be based on the experience gained by utilities and designers in France and in Germany. The reactor coolant boundary of a PWR includes the reactor pressure vessel (RPV), those parts of the steam generators (SGs) which contain primary coolant, the pressurizer (PSR), the reactor coolant pumps (RCPs), the main coolant lines (MCLs) with their branches as well as the other connecting pipes and all branching pipes including the second isolation valves. The present work covering the integrity of the reactor coolant boundary is mainly restricted to the integrity of the main coolant lines (MCLs) and reflects the design requirements for the main components of the reactor coolant boundary. In the following the conceptual aspects, i.e. design, manufacture, construction and operation, will be assessed. A main aspect is the definition of break postulates regarding overall safety implications.

  6. Selection of an Alternate Biocide for the ISS Internal Thermal Control System Coolant, Phase 2

    NASA Technical Reports Server (NTRS)

    Wilson, Mark E.; Cole, Harold; Weir, Natalee; Oehler, Bill; Steele, John; Varsik, Jerry; Lukens, Clark

    2004-01-01

    The ISS (International Space Station) ITCS (Internal Thermal Control System) includes two internal coolant loops that utilize an aqueous based coolant for heat transfer. A silver salt biocide had previously been utilized as an additive in the coolant formulation to control the growth and proliferation of microorganisms within the coolant loops. Ground-based and in-flight testing demonstrated that the silver salt was rapidly depleted, and did not act as an effective long-term biocide. Efforts to select an optimal alternate biocide for the ITCS coolant application have been underway and are now in the final stages. An extensive evaluation of biocides was conducted to down-select to several candidates for test trials and was reported on previously. Criteria for that down-select included: the need for safe, non-intrusive implementation and operation in a functioning system; the ability to control existing planktonic and biofilm residing microorganisms; a negligible impact on system-wetted materials of construction; and a negligible reactivity with existing coolant additives. Candidate testing to provide data for the selection of an optimal alternate biocide is now in the final stages. That testing has included rapid biocide effectiveness screening using Biolog MT2 plates to determine minimum inhibitory concentration (amount that will inhibit visible growth of microorganisms), time kill studies to determine the exposure time required to completely eliminate organism growth, materials compatibility exposure evaluations, coolant compatibility studies, and bench-top simulated coolant testing. This paper reports the current status of the effort to select an alternate biocide for the ISS ITCS coolant. The results of various test results to select the optimal candidate are presented.

  7. Cracked shaft detection on large vertical nuclear reactor coolant pump

    NASA Technical Reports Server (NTRS)

    Jenkins, L. S.

    1985-01-01

    Due to difficulty and radiation exposure associated with examination of the internals of large commercial nuclear reactor coolant pumps, it is necessary to be able to diagnose the cause of an excessive vibration problem quickly without resorting to extensive trial and error efforts. Consequently, it is necessary to make maximum use of all available data to develop a consistent theory which locates the problem area in the machine. This type of approach was taken at Three Mile Island, Unit #1, in February 1984 to identify and locate the cause of a continuously climbing vibration level of the pump shaft. The data gathered necessitated some in-depth knowledge of the pump internals to provide proper interpretation and avoid misleading conclusions. Therefore, the raw data included more than just the vibration characteristics. Pertinent details of the data gathered is shown and is necessary and sufficient to show that the cause of the observed vibration problem could logically only be a cracked pump shaft in the shaft overhang below the pump bearing.

  8. Numerical study: Iron corrosion-resistance in lead-bismuth eutectic coolant by molecular dynamics method

    SciTech Connect

    Arkundato, Artoto; Su'ud, Zaki; Abdullah, Mikrajuddin; Widayani,; Celino, Massimo

    2012-06-06

    In this present work, we report numerical results of iron (cladding) corrosion study in interaction with lead-bismuth eutectic coolant of advanced nuclear reactors. The goal of this work is to study how the oxygen can be used to reduce the corrosion rate of cladding. The molecular dynamics method was applied to simulate corrosion process. By evaluating the diffusion coefficients, RDF functions, MSD curves of the iron and also observed the crystal structure of iron before and after oxygen injection to the coolant then we concluded that a significant and effective reduction can be achieved by issuing about 2% number of oxygen atoms to lead-bismuth eutectic coolant.

  9. Analysis of an AP600 intermediate-size loss-of-coolant accident

    SciTech Connect

    Boyack, B.E.; Lime, J.F.

    1995-04-01

    A postulated double-ended guillotine break of an AP600 direct-vessel-injection line has been analyzed. This event is characterized as an intermediate-break loss-of-coolant accident. Most of the insights regarding the response of the AP600 safety systems to the postulated accident are derived from calculations performed with the TRAC-PF1/MOD2 code. However, complementary insights derived from a scaled experiment conducted in the ROSA facility, as well as insights based upon calculations by other codes, are also presented. Based upon the calculated and experimental results, the AP600 will not experience a core heat up and will reach a safe shutdown state using only safety-class equipment. Only the early part of the long-term cooling period initiated by In-containment Refueling Water Storage Tank injection was evaluated. Thus, the observation that the core is continuously cooled should be verified for the later phase of the long-term cooling period when sump injection and containment cooling processes are important.

  10. Analysis of an AP600 intermediate-size loss-of-coolant accident

    SciTech Connect

    Boyack, B.E.; Lime, J.F.

    1995-09-01

    A postulated double-ended guillotine break of an AP600 direct-vessel-injection line has been analyzed. This event is characterized as an intermediate-break loss-of-coolant accident. Most of the insights regarding the response of the AP600 safety systems to the postulated accident are derived from calculations preformed with the TRAC-PF1/MOD2 code. However, complementary insights derived from a scaled experiment conducted in the ROSA facility, as well as insights based upon calculations by other codes, are also presented. Based upon the calculated and experimental results, the AP600 will not experience a core heat up and will reach a safe shutdown state using only safety-class equipment. Only the early part of the long-term cooling period initiated by In-containment Refueling Water Storage Tank injection was evaluated. Thus, the observation that the core is continuously cooled should be verified for the later phase of the long-term cooling period when sump injection and containment cooling processes are important.

  11. Preliminary requirements for a Fluoride Salt-Cooled High-Temperature Test Reactor (FHTR)

    SciTech Connect

    Massie, M.; Forsberg, C.; Forget, B.; Hu, L. W.

    2012-07-01

    A Fluoride Salt-Cooled High-Temperature Test Reactor (FHTR) design is being developed at MIT to provide the first demonstration and test of a salt-cooled reactor using high-temperature fuel. The first step is to define the requirements. The top level requirements are (1) provide the confidence that a larger demonstration reactor is warranted and (2) develop the necessary data for a larger-scale reactor. Because requirements will drive the design of the FHTR, a significant effort is being undertaken to define requirements and understand the tradeoffs that will be required for a practical design. The preliminary requirements include specifications for design parameters and necessary tests of major reactor systems. Testing requirements include demonstration of components, systems, and procedures for refueling, instrumentation, salt temperature control to avoid coolant freezing, salt chemistry and volume control, tritium monitoring and control, and in-service inspection. Safety tests include thermal hydraulics, neutronics - including intrinsic core shutdown mechanisms such as Doppler feedback - and decay heat removal systems. Materials and coolant testing includes fuels (including mechanical wear and fatigue) and system corrosion behavior. Preliminary analysis indicates a thermal power output below 30 MW, an initial core using pebble-bed or prismatic-block fuel, peak outlet temperatures of at least 700 deg. C, and use of FLi{sup 7}Be ({sup 7}LiF-BeF{sub 2}) coolant. The option to change-out the reactor core, fuel type, and major components is being investigated. While the FHTR will be used for materials testing, its primary mission is as a reactor system performance test to enable the design and licensing of a FHR demonstration power reactor. (authors)

  12. Crack initiation in smooth fatigue specimens of austenitic stainless steel in light water reactor environments.

    SciTech Connect

    Chopra, O. K.; Smith, J. L.

    1999-04-08

    The fatigue design curves for structural materials specified in Section III of the ASME Boiler and Pressure Vessel Code are based on tests of smooth polished specimens at room temperature in air. The effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves; however, recent test data illustrate the detrimental effects of LWR coolant environments on the fatigue resistance of austenitic stainless steels (SSs). Certain loading and environmental conditions have led to test specimen fatigue lives that are significantly shorter than those obtained in air. Results of fatigue tests that examine the influence of reactor environments on crack initiation and crack growth of austenitic SSs are presented. Block loading was used to mark the fracture surface to determine crack length as a function of fatigue cycles in water environments, Crack lengths were measured by scanning electron microscopy. The mechanism for decreased fatigue life in LWR environments is discussed, and crack growth rates in the smooth fatigue specimens are compared with existing data from studies of crack growth rates.

  13. An analysis method for multistage transonic turbines with coolant mass flow addition

    SciTech Connect

    Mildner, F.; Gallus, H.E.

    1998-10-01

    The subject of this paper is a numerical method for the calculation of the transonic flow field of multistage turbines, taking high coolant flow into account. To reduce the processing time, a throughflow method based on the principles of Wu is used for the hub-to-tip calculation. The flow field is obtained by an iterative solution between a three-dimensional inviscid hyperbolic time-dependent algorithm with an implicit finite volume method for the blade-to-blade calculations using C-meshes and a single representative meridional S{sub 2m}-stream surface. Along the 2{sub 2m}-plane with respect to nonorthogonal curvilinear coordinates, the stream function equation governing fluid flow is established. The cooling air inflow inside the blade passage forbids the assumption of a constant mass flow along the main stream direction. To consider the change of the aerodynamic and thermodynamic behavior, a cooling air model was developed and implemented in the algorithm, which allows the mixing of radially arbitrarily distributed cooling air in the trailing edge section of each blade row. The viscous effects and the influence of cooling air mixing are considered by the use of selected loss correlations for profile, tip leakage, secondary flow and mixing losses in the S{sub 2m}-plane in terms of entropy. The method is applied to the four-stage high-temperature gas turbine Siemens KWU V84.3. The numerical results obtained are in good agreement with the experimental data.

  14. Interaction study between MOX fuel and eutectic lead-bismuth coolant

    NASA Astrophysics Data System (ADS)

    Vigier, Jean-François; Popa, Karin; Tyrpekl, Vaclav; Gardeur, Sébastien; Freis, Daniel; Somers, Joseph

    2015-12-01

    In the frame of the MYRRHA reactor project, the interaction between fuel pellets and the reactor coolant is essential for safety evaluations, e.g. in case of a pin breach. Therefore, interaction tests between uranium-plutonium mixed oxide (MOX) pellets and molten lead bismuth eutectic (LBE) have been performed and three parameters were studied, namely the interaction temperature (500 °C and 800 °C), the oxygen content in LBE and the stoichiometry of the MOX (U0.7Pu0.3O2-x and U0.7Pu0.3O2.00). After 50 h of interaction in closed containers, the pellet integrity was preserved in all cases. Whatever the conditions, neither interaction compounds (crystalline or amorphous) nor lead and bismuth diffusion into the surface regions of the MOX pellets has been detected. In most of the conditions, actinide releases into LBE were very limited (in the range of 0.01-0.15 mg), with a homogeneous release of the different actinides present in the MOX. Detected values were significantly higher in the 800 °C and low LBE oxygen content tests for both U0.7Pu0.3O2-x and U0.7Pu0.3O2.00, with 1-2 mg of actinide released in these conditions.

  15. Sodium coolant purification systems for a nuclear power station equipped with a BN-1200 reactor

    NASA Astrophysics Data System (ADS)

    Alekseev, V. V.; Kovalev, Yu. P.; Kalyakin, S. G.; Kozlov, F. A.; Kumaev, V. Ya.; Kondrat'ev, A. S.; Matyukhin, V. V.; Pirogov, E. P.; Sergeev, G. P.; Sorokin, A. P.; Torbenkova, I. Yu.

    2013-05-01

    Both traditional coolant purification methods (by means of traps and sorbents for removing cesium), the use of which supported successful operation of nuclear power installations equipped with fast-neutron reactors with a sodium coolant, and the possibility of removing oxygen from sodium through the use of hot traps are analyzed in substantiating the purification system for a nuclear power station equipped with a BN-1200 reactor. It is shown that a cold trap built into the reactor vessel must be a mandatory component of the reactor plant primary coolant circuit's purification system. The use of hot traps allows oxygen to be removed from the sodium coolant down to permissible concentrations when the nuclear power station operates in its rated mode. The main lines of works aimed at improving the performance characteristics of cold traps are suggested based on the results of performed investigations.

  16. Hot-Gas-Slide and Coolant-Side Heat Transfer in Liquid Rocket Engine Combustors

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Luong, Van

    1994-01-01

    The objectives of this article are to develop a multidisciplinary, computational methodology to predict the hot-gas-side and coolant-side heat transfer in film cooling assisted, regeneratively cooled liquid rocket engine combustors, and to use it in parametric studies to recommend optimized design of the coolant channels for a developmental combustor. An integrated numerical model which incorporates computational fluid dynamics (CFD) for the hot-gas thermal environment, and thermal analysis for the liner and coolant channels, was developed. This integrated CFD/thermal model was validated by comparing predicted heat fluxes with those of hot-firing test and industrial design methods for a 40-k calorimeter thrust chamber and the Space Shuttle Main Engine main combustion chamber. Parametric studies were performed for the advanced main combustion chamber to find a strategy for a proposed coolant channel design.

  17. Thermal transfer structures coupling electronics card(s) to coolant-cooled structure(s)

    DOEpatents

    David, Milnes P; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Parida, Pritish R; Schmidt, Roger R

    2014-12-16

    Cooling apparatuses and coolant-cooled electronic systems are provided which include thermal transfer structures configured to engage with a spring force one or more electronics cards with docking of the electronics card(s) within a respective socket(s) of the electronic system. A thermal transfer structure of the cooling apparatus includes a thermal spreader having a first thermal conduction surface, and a thermally conductive spring assembly coupled to the conduction surface of the thermal spreader and positioned and configured to reside between and physically couple a first surface of an electronics card to the first surface of the thermal spreader with docking of the electronics card within a socket of the electronic system. The thermal transfer structure is, in one embodiment, metallurgically bonded to a coolant-cooled structure and facilitates transfer of heat from the electronics card to coolant flowing through the coolant-cooled structure.

  18. 120. COOLANT LINES TO SIS HEAT EXCHANGER No.1 IN AUXILIARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    120. COOLANT LINES TO SIS HEAT EXCHANGER No.1 IN AUXILIARY CHAMBER, NOVEMBER 1, 1976 - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  19. The experience in handling of lead-bismuth coolant contaminated by Polonium-210

    SciTech Connect

    Pankratov, D.V.; Gromov, B.F.; Solodjankin, M.A.

    1993-12-31

    During exploitation of lead-bismuth cooled reactors a wide experience in handling of radioactive coolant containing polonium has been gained. By 1990 total time of this reactor operation has reached approximately 60 reactor years.

  20. Initial Changes in the Transcriptome of Euphorbia esula Seeds Induced to Germinate with a Combination of Constant and Diurnal Alternating Temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated transcriptome changes in Euphorbia esula (leafy spurge) seeds with a focus on the effect of constant and diurnal fluctuating temperature on dormancy and germination. Leafy spurge seeds do not germinate when incubated for 21 days at 20°C constant temperatures, but nearly 30% germinate...

  1. Reactor coolant pump testing using motor current signatures analysis

    SciTech Connect

    Burstein, N.; Bellamy, J.

    1996-12-01

    This paper describes reactor coolant pump motor testing carried out at Florida Power Corporation`s Crystal River plant using Framatome Technologies` new EMPATH (Electric Motor Performance Analysis and Trending Hardware) system. EMPATH{trademark} uses an improved form of Motor Current Signature Analysis (MCSA), technology, originally developed at Oak Ridge National Laboratories, for detecting deterioration in the rotors of AC induction motors. Motor Current Signature Analysis (MCSA) is a monitoring tool for motor driven equipment that provides a non-intrusive means for detecting the presence of mechanical and electrical abnormalities in the motor and the driven equipment. The base technology was developed at the Oak Ridge National Laboratory as a means for determining the affects of aging and service wear specifically on motor-operated valves used in nuclear power plant safety systems, but it is applicable to a broad range of electric machinery. MCSA is based on the recognition that an electric motor (ac or dc) driving a mechanical load acts as an efficient and permanently available transducer by sensing mechanical load variations, large and small, long-term and rapid, and converting them into variations in the induced current generated in the motor windings. The motor current variations, resulting from changes in load caused by gears, pulleys, friction, bearings, and other conditions that may change over the life of the motor, are carried by the electrical cables powering the motor and are extracted at any convenient location along the motor lead. These variations modulate the 60 Hz carrier frequency and appear as sidebands in the spectral plot.

  2. Correct numerical simulation of a two-phase coolant

    NASA Astrophysics Data System (ADS)

    Kroshilin, A. E.; Kroshilin, V. E.

    2016-02-01

    Different models used in calculating flows of a two-phase coolant are analyzed. A system of differential equations describing the flow is presented; the hyperbolicity and stability of stationary solutions of the system is studied. The correctness of the Cauchy problem is considered. The models' ability to describe the following flows is analyzed: stable bubble and gas-droplet flows; stable flow with a level such that the bubble and gas-droplet flows are observed under and above it, respectively; and propagation of a perturbation of the phase concentration for the bubble and gas-droplet media. The solution of the problem about the breakdown of an arbitrary discontinuity has been constructed. Characteristic times of the development of an instability at different parameters of the flow are presented. Conditions at which the instability does not make it possible to perform the calculation are determined. The Riemann invariants for the nonlinear problem under consideration have been constructed. Numerical calculations have been performed for different conditions. The influence of viscosity on the structure of the discontinuity front is studied. Advantages of divergent equations are demonstrated. It is proven that a model used in almost all known investigating thermohydraulic programs, both in Russia and abroad, has significant disadvantages; in particular, it can lead to unstable solutions, which makes it necessary to introduce smoothing mechanisms and a very small step for describing regimes with a level. This does not allow one to use efficient numerical schemes for calculating the flow of two-phase currents. A possible model free from the abovementioned disadvantages is proposed.

  3. Loss-of-coolant accident analyses of the Advanced Neutron Source Reactor

    SciTech Connect

    Chen, N.C.J.; Yoder, G.L. ); Wendel, M.W. )

    1991-01-01

    Currently in the conceptual design stage, the Advanced Neutron Source Reactor (ANSR) will operate at a high heat flux, a high mass flux, an a high degree of coolant subcooling. Loss-of-coolant accident (LOCA) analyses using RELAP5 have been performed as part of an early evaluation of ANSR safety issues. This paper discusses the RELAP5 ANSR conceptual design system model and preliminary LOCA simulation results. Some previous studies were conducted for the preconceptual design. 12 refs., 7 figs.

  4. Influence of coolant tube curvature on film cooling effectiveness as detected by infrared imagery

    NASA Technical Reports Server (NTRS)

    Papell, S. S.; Graham, R. W.; Cageao, R. P.

    1979-01-01

    Thermal film cooling footprints observed by infrared imagery from straight, curved, and looped coolant tube geometries are compared. It was hypothesized that the differences in secondary flow and in the turbulence structure of flow through these three tubes should influence the mixing properties between the coolant and the main stream. A flow visualization tunnel, an infrared camera and detector, and a Hilsch tube were employed to test the hypothesis.

  5. Cooling of Gas Turbines. 3; Analysis of Rotor and Blade Temperatures in Liquid-Cooled Gas Turbines

    NASA Technical Reports Server (NTRS)

    Brown, W. Byron; Livingood, John N. B.

    1947-01-01

    A theoretical analysis of the radial temperature distribution through the rotor and constant cross sectional area blades near the coolant passages of liquid cooled gas turbines was made. The analysis was applied to obtain the rotor and blade temperatures of a specific turbine using a gas flow of 55 pounds per second, a coolant flow of 6.42 pounds per second, and an average coolant temperature of 200 degrees F. The effect of using kerosene, water, and ethylene glycol was determined. The effect of varying blade length and coolant passage lengths with water as the coolant was also determined. The effective gas temperature was varied from 2000 degrees to 5000 degrees F in each investigation.

  6. Impact of the propylene glycol-water-borax coolant on material recovery operations

    SciTech Connect

    Duerksen, W.K.; Taylor, P.A.

    1983-05-01

    The reaction of the propylene glycol-water-borax coolant with nitric acid has now been studied in some detail. This document is intended to provide a summary of the results. Findings are summarized under nine headings. Tests have also been conducted to determine if the new coolant would have any adverse effects on the uranium recycle systems. Experiments were scientifically designed after observation of the production operations so that accurate response to the immediate production concerns could be provided. Conclusions from these studies are: formation of glycol nitrates is very improbable; the reaction of concentrated (70%) nitric acid with pure propylene glycol is very violent and hazardous; dilution of the nitric acid-glycol mixture causes a drastic decrease in the rate and intensity of the reaction; the mechanism of the nitric acid propylene glycol reaction is autocatalytic in nitrous acid; no reaction is observed between coolant and 30% nitric acid unless the solution is heated; the coolant reacts fairly vigorously with 55% nitric acid after a concentration-dependent induction time; experiments showed that the dissolution of uranium chips that had been soaked in coolant proceeded at about the same rate as if the chips had not previously contacted glycol; thermodynamic calculations show that the enthalpy change (heat liberated) by the reaction of nitric acid (30%) with propylene glycol is smaller than if the same amount of nitric acid reacted with uranium. Each of these conclusions is briefly discussed. The effect of new coolant on uranium recycle operations is then briefly discussed.

  7. Modeling electrodeposition of charged nanoparticles onto fuel cell coolant flow channel walls

    NASA Astrophysics Data System (ADS)

    Cheng, J.-T.

    2008-10-01

    To cool down the stack system in polymer electrolyte fuel cells (PEFCs), a coolant is needed that must be electrically nonconductive. In the specialized coolant that is modeled by us, charged nanoparticles are added into the flow to neutralize the ion contamination that otherwise gradually degrades the coolant until shunt currents become significant. A computational fluid dynamics (CFD) physicochemical model of the multiphase coolant flow with charged nanoparticles has been formulated and coded using COMSOL Multiphysics and MEMS. Electrochemistry, fluid mechanics, steric stabilization, and heat transfer are coupled in this model. For nanoparticles in the fluid, electrokinetic force, electrical double layer (EDL) force, hydrodynamic force, and buoyancy force have been taken into account for the prediction of the electrodeposition rate onto channel walls. The overall goal of the model is to provide a fundamental first principles-based design tool for a specialized coolant to enable operations in a fuel cell stack for 2-3 years without the need for frequent replacement or filtering of the coolant.

  8. ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project -2006 Update

    NASA Technical Reports Server (NTRS)

    Morrison, Russell H.; Holt, Mike

    2006-01-01

    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. This paper presents a status of the coolant stability over the past year as well as results from destructive analyses of hardware removed from the on-orbit system and the current approach to coolant remediation.

  9. High Pressure Coolant Injection (HPCI) System Risk-Based Inspection Guide for Browns Ferry Nuclear Power Station

    SciTech Connect

    Wong, S.; DiBiasio, A.; Gunther, W.

    1993-09-01

    The High Pressure Coolant Injection (HPCI) system has been examined from a risk perspective. A System Risk-Based Inspection Guide (S-RIG) has been developed as an aid to HPCI system inspections at the Browns Ferry Nuclear Power Plant, Units 1, 2 and 3. The role of. the HPCI system in mitigating accidents is discussed in this S-RIG, along with insights on identified risk-based failure modes which could prevent proper operation of the system. The S-RIG provides a review of industry-wide operating experience, including plant-specific illustrative examples to augment the PRA and operational considerations in identifying a catalogue of basic PRA failure modes for the HPCI system. It is designed to be used as a reference for routine inspections, self-initiated safety system functional inspections (SSFIs), and the evaluation of risk significance of component failures at the nuclear power plant.

  10. Evaluation of SCC test methods for Inconel 600 in low-temperature aqueous solutions

    SciTech Connect

    Newman, R.C.; Roberge, R.; Bandy, R.

    1984-01-01

    In late 1981, widespread leakage was encountered in Alloy 66 steam generator tubing at the Three Mile Island Unit 1 nuclear power plant. The phenomenon was identified as low-temperature intergranular stress-corrosion cracking (SCC) initiated from the inner surfaces of the tubes exposed to the primary coolant. A testing program was initiated to examine the material and environmental factors relevant to these failures, which were found to be associated with sensitization of the material and contamination of the coolant by air and sodium thiosulfate. The test solutions contained 1.3% boric acid with various additions of sulfur compounds and lithium hydroxide. Constant extension rate testing was used as the primary tool to examine environmental effects such as the inhibition of cracking by lithium hydroxide. Important effects of crack initiation, and the effects of further environmental additions were monitored by following the load decay at constant total strain. This procedure generally resulted in a different ranking of the environments. U-bend tests showed that the ranking of different sulfur-containing environments was also highly dependent on the metal heat treatment.

  11. A numerical study of the temperature field in a cooled radial turbine rotor

    NASA Technical Reports Server (NTRS)

    Hamed, A.; Baskharone, E.; Tabakoff, W.

    1977-01-01

    The three dimensional temperature distribution in the cooled rotor of a radial inflow turbine is determined numerically using the finite element method. Through this approach, the complicated geometries of the hot rotor and coolant passage surfaces are handled easily, and the temperatures are determined without loss of accuracy at these convective boundaries. Different cooling techniques with given coolant to primary flow ratios are investigated, and the corresponding rotor temperature fields are presented for comparison.

  12. Investigations of coolant stratification and temperature pulsations in nuclear power installations

    NASA Astrophysics Data System (ADS)

    Zaryugin, D. G.; Kolyakin, S. G.; Opanasenko, A. N.; Sorokin, A. P.

    2013-03-01

    Specific features of stratified flows are considered taking fast-neutron reactors as an example, the possibilities of scale-wise simulation of such flows are discussed, and some results obtained from experimental and numerical investigations of flows in mixing chambers and pipelines are presented. The mixing of sodium jets in the upper chamber at the outlet from the fast-neutron reactor core is analyzed.

  13. Probability of pipe fracture in the primary coolant loop of a PWR plant. Volume 6: failure mode analysis. Final report

    SciTech Connect

    Streit, R.D.

    1981-09-01

    Material properties and failure criteria were evaluated to assess the requirements for double-ended guillotine break in the primary coolant loop of the Zion Unit 1 pressurized water reactor. The properties of the 316 stainless steel piping materials were obtained from the literature. Statistical distributions of both the tensile and fracture properties at room and operating temperatures were developed. Yield and ultimate strength tensile properties were combined to estimate the material flow strength. The flow strength and fracture properties were used in the various failure models analyzed. Linear-elastic, elastic-plastic, and fully plastic fracture models were compared, and the governing fracture criterion was determined. For the particular case studied, the fully plastic flow requirement was found to be the controlling fracture criterion leading to a double-ended guillotine pipe break.

  14. Hydrothermal corrosion of SiC in LWR coolant environments in the absence of irradiation

    NASA Astrophysics Data System (ADS)

    Terrani, K. A.; Yang, Y.; Kim, Y.-J.; Rebak, R.; Meyer, H. M.; Gerczak, T. J.

    2015-10-01

    Assessment of the thermodynamics of SiC corrosion under light water reactor coolant environments suggests that silica formation is always expected in the range of applicable pH and potential. Autoclave testing of SiC-based materials in the absence of ionizing radiation was performed. The kinetics data from these tests, when compared with kinetics of silica dissolution in water and post-exposure characterization of SiC samples, suggest that oxidation of SiC to form silica is the rate-limiting step for recession of SiC in high temperature water. Oxygen activity in water was determined to play an important role in SiC recession kinetics. A simplified model of a power loop shows the effect of silica dissolution from the hot region (resembling fuel) and deposition in the cold regions.

  15. Thermal criteria to compare fast reactors coolants for the intermediate loop

    SciTech Connect

    Saez, Manuel; Rodriguez, Gilles

    2007-07-01

    Fast Breeder Reactors (FBR) are typically using a liquid metal as the primary coolant. Up to now, sodium is the referenced coolant for all large-scale FBR, but lead and sodium-potassium alloy have both also been used successfully for smaller rigs. The French Atomic Energy Commission (CEA) has an extensive experience and significant expertise in Sodium cooled Fast Reactors (SFR) over the past 40 years of R and D and feedback experiments. Some improvements are needed on the SFR to meet the Generation IV goals, and in particular the safety and the reliability through the intermediate loop coolant. As sodium reacts exo-thermically with air and water and to eliminate the drawback of the water-sodium interaction when a steam generator tube is ruptured, CEA is involved in a substantial effort in order to investigate the interest to use an alternative coolant than sodium in the intermediate loop. This paper presents the main thermal criteria to compare Fast Reactors coolants for the intermediate loop under natural and forced convection. Neutronics considerations are not taken into account for the intermediate loop coolant. Transport, transfer and energetic criteria are analysed in the field of turbulent flows. Criteria are applied to the following potential coolant candidates: sodium, lithium, tin, bismuth, lead, lead-bismuth alloy, lead-lithium alloy, gallium, indium, potassium and sodium-potassium alloy. According to this thermal analysis, the gallium as heat transfer agent for the intermediate loop is considered as a promising candidate. For the discussion of the applicability of the gallium as heat transfer agent for the intermediate loop, a limited thermal hydraulic pre-sizing of a steam generator is undertaken using simple engineering methods implemented in COPERNIC code, a CEA tool dedicated to reactor systems pre-sizing. (authors)

  16. Experimental investigation on the chemical precipitation generation under the loss of coolant accident of nuclear power plants

    SciTech Connect

    Kim, C. H.; Sung, J. J.; Chung, Y. W.

    2012-07-01

    The PWR containment buildings are designed to facilitate core cooling in the event of a Loss of Coolant Accident (LOCA). The cooling process requires water discharged from the break and containment spray to be collected in a sump for recirculation. The containment sump contains screens to protect the components of the Emergency Core Cooling System (ECCS) and Containment Spray System (CSS) from debris. Since the containment materials may dissolve or corrode when exposed to the reactor coolant and spray solutions, various chemical precipitations can be generated in a post-LOCA environment. These chemical precipitations may become another source of debris loading to be considered in sump screen performance and downstream effects. In this study, new experimental methodology to predict the type and quantity of chemical precipitations has been developed. To generate the plant-specific chemical precipitation in a post-LOCA environment, the plant specific chemical condition of the recirculation sump during post-LOCA is simulated with the experimental reactor for the chemical effect. The plant-specific containment materials are used in the present experiment such as glass fibers, concrete blocks, aluminum specimens, and chemical reagent - boric acid, spray additives or buffering chemicals (sodium hydroxide, Tri-Sodium Phosphate (TSP), or others). The inside temperature of the reactor is controlled to simulate the plant-specific temperature profile of the recirculation sump. The total amount of aluminum released from aluminum specimens is evaluated by ICP-AES analysis to determine the amount of AlOOH and NaAlSi{sub 3}O{sub 8} which induce very adverse effect on the head loss across the sump screens. The amount of these precipitations generated in the present experimental study is compared with the results of WCAP-16530-NP-A. (authors)

  17. Temperature-sensitive initiation and elongation of adenovirus DNA replication in vitro with nuclear extracts from H5ts36-, H5ts149-, and H5ts125-infected HeLa cells.

    PubMed Central

    van Bergen, B G; van der Vliet, P C

    1983-01-01

    Adenovirus DNA replication was studied in vitro in nuclear extracts prepared from HeLa cells infected at the permissive temperature with H5ts125, H5ts36, or H5ts149, three DNA-negative mutants belonging to two different complementation groups. At the restrictive temperature, H5ts125 extracts, containing a thermolabile 72-kilodalton DNA-binding protein, enable the formation of an initiation complex between the 82-kilodalton terminal protein precursor (pTP) and dCTP, but further elongation of this complex is inhibited. Wild-type DNA-binding protein or a 47-kilodalton chymotryptic DNA-binding fragment can complement the mutant protein in the elongation reaction. No difference in heat inactivation was observed between wild-type extracts and H5ts36 or H5ts149 extracts when the replication of terminal XbaI fragments of adenovirus type 5 DNA-terminal protein complex was studied. In contrast, the formation of a pTP-dCMP initiation complex, as well as the partial elongation reaction up to nucleotide 26, were consistently more temperature sensitive in mutant extracts. The results suggest that the H5ts36/H5ts149 gene product is required for initiation of adenovirus type 5 DNA replication and that the 72-kilodalton DNA-binding protein functions early in elongation. Images PMID:6302326

  18. Probability of failure in BWR reactor coolant piping: Volume 1, Summary report

    SciTech Connect

    Holman, G.S.; Chou, C.K.

    1989-03-01

    This report summarizes a probabilistic reliability evaluation of BWR reactor coolant piping performed for the US Nuclear Regulatory Commission (NRC) by the Lawrence Livermore National Laboratory (LLNL). In this evaluation, LLNL estimated the probability of a double-ended guillotine break (DEGB) in the main steam, feedwater, and recirculation loop piping of a representative Mark I BWR plant. Two causes of pipe break were considered: crack growth at welded joints, and the earthquake-induced failure of supports for piping and components. A probabilistic fracture mechanics model, including intergranular stress corrosion cracking (IGSCC) in Types 304 and 316NG stainless steels, was used to estimate the probability of crack-induced pipe break. The probability of pipe break indirectly caused by support failure was estimated by applying reliability techniques to supports for ''heavy components'' such as the reactor pressure vessel, as well as to conventional pipe supports such as spring hangers and snubbers. Our probabilistic fracture mechanics evaluation found that the probability of crack-induced DEGB in main steam, feedwater and, if IGSCC is not a factor, recirculation piping is very low. In ISGCC-susceptible Type 304SS piping, stress corrosion dominates the probability of DEGB due mainly to cracks that initiate during the first few years of plant life; replacing Type 304 piping with IGSCC-resistant Type 316NG lowers DEGB probabilities by several orders of magnitude. We also found that the probability of pipe break caused by seismically-induced support failure is low regardless of whether ''heavy component'' supports or conventional pipe supports are being considered. 23 refs., 34 figs., 16 tabs.

  19. Reactor Coolant Pump seal issues and their applicability to new reactor designs

    SciTech Connect

    Ruger, C.J.; Higgins, J.C.

    1993-11-01

    Reactor Coolant Pumps (RCPs) of various types are used to circulate the primary coolant through the reactor in most reactor designs. RCPs generally contain mechanical seals to limit the leakage of pressurized reactor coolant along the pump drive shaft into the containment. The relatively large number of RCP seal and seal auxiliary system failures experienced at US operating plants during the 1970`s and early 1980`s raised concerns from the US Nuclear Regulatory Commission (NRC) that gross failures may lead to reactor core uncovery and subsequent core damage. Some seal failure events resulted in a loss of primary coolant to the containment at flow rates greater than the normal makeup capacity of Pressurized Water Reactor (PWR) plants. This is an example of RCP seal failures resulting in a small Loss of Coolant Accident (LOCA). This paper discusses observed and potential causes of RCP seal failure and the recommendations for limiting the likelihood of a seal induced small LOCA. Issues arising out of the research supporting these recommendations and subsequent public comments by the utility industry on them, serve as lessons learned, which are applicable to the design of new reactor plants.

  20. Models and numerical methods for the simulation of loss-of-coolant accidents in nuclear reactors

    NASA Astrophysics Data System (ADS)

    Seguin, Nicolas

    2014-05-01

    In view of the simulation of the water flows in pressurized water reactors (PWR), many models are available in the literature and their complexity deeply depends on the required accuracy, see for instance [1]. The loss-of-coolant accident (LOCA) may appear when a pipe is broken through. The coolant is composed by light water in its liquid form at very high temperature and pressure (around 300 °C and 155 bar), it then flashes and becomes instantaneously vapor in case of LOCA. A front of liquid/vapor phase transition appears in the pipes and may propagate towards the critical parts of the PWR. It is crucial to propose accurate models for the whole phenomenon, but also sufficiently robust to obtain relevant numerical results. Due to the application we have in mind, a complete description of the two-phase flow (with all the bubbles, droplets, interfaces…) is out of reach and irrelevant. We investigate averaged models, based on the use of void fractions for each phase, which represent the probability of presence of a phase at a given position and at a given time. The most accurate averaged model, based on the so-called Baer-Nunziato model, describes separately each phase by its own density, velocity and pressure. The two phases are coupled by non-conservative terms due to gradients of the void fractions and by source terms for mechanical relaxation, drag force and mass transfer. With appropriate closure laws, it has been proved [2] that this model complies with all the expected physical requirements: positivity of densities and temperatures, maximum principle for the void fraction, conservation of the mixture quantities, decrease of the global entropy… On the basis of this model, it is possible to derive simpler models, which can be used where the flow is still, see [3]. From the numerical point of view, we develop new Finite Volume schemes in [4], which also satisfy the requirements mentioned above. Since they are based on a partial linearization of the physical

  1. High-Temperature High-Power Packaging Techniques for HEV Traction Applications

    SciTech Connect

    Barlow, F.D.; Elshabini, A.

    2006-11-30

    reduction of these systems could be achieved is through the use of a single coolant loop for both the power electronics as well as the internal combustion engine (ICE) [2]. This change would reduce the complexity of the cooling system which currently relies on two loops to a single loop [3]. However, the current nominal coolant temperature entering these inverters is 65 C [3], whereas a normal ICE coolant temperature would be much higher at approximately 100 C. This change in coolant temperature significantly increases the junction temperatures of the devices and creates a number of challenges for both device fabrication and the assembly of these devices into inverters and converters for HEV and PHEV applications. With this change in mind, significant progress has been made on the use of SiC devices for inverters that can withstand much higher junction temperatures than traditional Si based inverters [4,5,6]. However, a key problem which the single coolant loop and high temperature devices is the effective packaging of these devices and related components into a high temperature inverter. The elevated junction temperatures that exist in these modules are not compatible with reliable inverters based on existing packaging technology. This report seeks to provide a literature survey of high temperature packaging and to highlight the issues related to the implementation of high temperature power electronic modules for HEV and PHEV applications. For purposes of discussion, it will be assumed in this report that 200 C is the targeted maximum junction temperature.

  2. The effect of coolant orificing on the core performance of a heterogeneous liquid-metal fast breeder reactor

    SciTech Connect

    Mamoru, K.; Shigehiro, A.; Yoshiaki, O.

    1983-04-01

    The effect of orificing on the core performance of a commercial-size heterogeneous liquid-metal fast breeder reactor was studied analytically. The thermal power output was flattened at beginning of life, and the coolant flow rate was chosen such that the maximum inner cladding temperature of a driver fuel and a blanket fuel was less than or equal to 620/sup 0/C at both beginning of equilibrium life (BOEL) and end of equilibrium life (EOEL). The difference between reactor outlet temperatures at BOEL and EOEL was then calculated for six core configurations: one homogeneous core configuration and five heterogeneous ones. The results showed that the core outlet temperature variation due to the change of the power profile of the radial heterogeneous core configurations is similar to that of the homogeneous one, even when a single type of orificing is used in each core zone, and it will not be necessary to use the more detailed orificing in each zone of a heterogeneous core configuration. The study concludes that for the present design, especially the thermal design, of some heterogeneous core configurations, it is feasible to control the change of the reactor outlet temperature with burnup, even when a single type of orificing is used in each core zone.

  3. Initial growth stages of Si–Ge–Sn ternary alloys grown on Si (100) by low-temperature molecular-beam epitaxy

    SciTech Connect

    Tuktamyshev, A. R. Mashanov, V. I.; Timofeev, V. A.; Nikiforov, A. I.; Teys, S. A.

    2015-12-15

    Temperature dependence of the critical thickness of the transition from two-dimensional to threedimensional growth of the Ge{sub 1–5x}Si{sub 4x}Sn{sub x} films grown on Si (100) by molecular-beam epitaxy in the temperature range 150–450°C has been experimentally determined. This dependence is nonmonotonic and is similar to that of the critical thickness for the transition from two-dimensional to three-dimensional growth in the case of the deposition of pure Ge on Si (100) and is caused by a change in the mechanism of two-dimensional growth. Data on the average size and the density of islands, and the ratio between the height of the islands and their lateral size are obtained by the methods of atomic force microscopy and scanning tunneling microscopy. As the growth temperature is increased from 200 to 400°C, the average size of the nanoislands increases from 4.7 to 23.6 nm.

  4. The Institute for Rock Magnetism and its Role in Initiating Routine Low-Temperature Magnetic Measurements in Environmental Magnetism, Rock Magnetism and Paleomagnetism.

    NASA Astrophysics Data System (ADS)

    Banerjee, S. K.; Moskowitz, B. M.; Jackson, M. J.; Marvin, J. A.; Solheid, P. A.

    2002-12-01

    Magnetic minerals in rocks and sediments are information repositories for past changes in the geological or planetary environment, preserved in the varying composition, concentration, grain size and overall magnetic alignment of the magnetic species: iron oxides, hydroxides, carbonates and sulfides. The creation of the Institute for Rock Magnetism, with the support of the National Science Foundation's Earth Science Division, the Keck Foundation and the University of Minnesota - Twin Cities, has meant that scientists who use paleomagnetism and rock magnetism can have some of their most basic questions answered through cooperative research at the IRM. In the last decade, scientists from two other disciplines -- global environmental change and biomagnetism -- have also utilized the IRM for controlled experiments on target minerals, sometimes as small as 5 nm, to interpret in a more quantitative manner the amplitudes of past variations. Of all the instruments made available to the magnetics community by the IRM, e.g., high and low field magnetometers, particle size analyzers, M”ssbauer spectrometers and magneto-optic and magnetic force microscopes, it is the SQUID susceptometers (operating at temperatures down to 1.5K and magnetic fields from zero to 5 Tesla) that have made the most impact on the science. In-house researchers and NSF/EAR-supported visiting fellows have made a number of discoveries based on new fundamental knowledge of low temperature magnetism of the following 8 minerals: (titano)magnetite, hematite, goethite, lepidocrocite, ferrihydrite, siderite, rhodochrocite and pyrrhotite. For a significant number of U.S. and international geologists and geophysicists, thermal demagnetization of low temperature (~10-20K) magnetizations has now become the most widely-used non-destructive technique for recognition and estimation of (a) magnetite in natural sediments, (b) glacial/interglacial climate change records in worldwide loess deposits and (c) paleoredox

  5. Numerical analysis of the hot-gas-side and coolant-side heat transfer in liquid rocket engine combustors

    NASA Technical Reports Server (NTRS)

    Wang, T. S.; Luong, V.

    1992-01-01

    The objectives of this paper are to develop computational methods to predict the hot-gas-side and coolant-side heat transfer, and to use these methods in parametric studies to recommend optimized design of the coolant channels for regeneratively cooled liquid rocket engine combustors. An integrated numerical model which incorporates computational fluid dynamics (CFD) for the hot-gas thermal environment, and thermal analysis for the coolant channels, was developed. The mode was validated by comparing predicted heat fluxes with those of hot-firing test and industrial design methods. Parametric studies were performed to find a strategy for optimized combustion chamber coolant channel design.

  6. Analysis of Kuosheng Large-Break Loss-of-Coolant Accident with MELCOR 1.8.4

    SciTech Connect

    Wang, T.-C.; Wang, S.-J.; Chien, C.-S

    2000-09-15

    The MELCOR code, developed by Sandia National Laboratories, is capable of simulating the severe accident phenomena of light water reactor nuclear power plants (NPPs). A specific large-break loss-of-coolant accident (LOCA) for Kuosheng NPP is simulated with the use of the MELCOR 1.8.4 code. This accident is induced by a double-ended guillotine break of one of the recirculation pipes concurrent with complete failure of the emergency core cooling system. The MELCOR input deck for the Kuosheng NPP is established based on the design data of the Kuosheng NPP and the MELCOR users' guides. The initial steady-state conditions are generated with a developed self-initialization algorithm. The effect of the MELCOR 1.8.4-provided initialization process is demonstrated. The main severe accident phenomena and the corresponding fission product released fractions associated with the large-break LOCA sequences are simulated. The MELCOR 1.8.4 predicts a longer time interval between the core collapse and vessel failure and a higher source term. This MELCOR 1.8.4 input deck will be applied to the probabilistic risk assessment, the severe accident analysis, and the severe accident management study of the Kuosheng NPP in the near future.

  7. Method and apparatus for controlling hybrid powertrain system in response to engine temperature

    SciTech Connect

    Martini, Ryan D; Spohn, Brian L; Lehmen, Allen J; Cerbolles, Teresa L

    2014-10-07

    A method for controlling a hybrid powertrain system including an internal combustion engine includes controlling operation of the hybrid powertrain system in response to a preferred minimum coolant temperature trajectory for the internal combustion engine.

  8. Research Initiatives

    Cancer.gov

    This page provides detailed information about currently funded RFA initiatives both led by DCCPS, and those led by other NIH Institutes and Centers (I/Cs) that include DCCPS as a partner. Each initiative includes a table of funded grants and a map that shows the location of funded institutions.

  9. Advanced Thermal Storage for Central Receivers with Supercritical Coolants

    SciTech Connect

    Kelly, Bruce D.

    2010-06-15

    The principal objective of the study is to determine if supercritical heat transport fluids in a central receiver power plant, in combination with ceramic thermocline storage systems, offer a reduction in levelized energy cost over a baseline nitrate salt concept. The baseline concept uses a nitrate salt receiver, two-tank (hot and cold) nitrate salt thermal storage, and a subcritical Rankine cycle. A total of 6 plant designs were analyzed, as follows: Plant Designation Receiver Fluid Thermal Storage Rankine Cycle Subcritical nitrate salt Nitrate salt Two tank nitrate salt Subcritical Supercritical nitrate salt Nitrate salt Two tank nitrate salt Supercritical Low temperature H2O Supercritical H2O Two tank nitrate salt Supercritical High temperature H2O Supercritical H2O Packed bed thermocline Supercritical Low temperature CO2 Supercritical CO2 Two tank nitrate salt Supercritical High temperature CO2 Supercritical CO2 Packed bed thermocline Supercritical Several conclusions have been drawn from the results of the study, as follows: 1) The use of supercritical H2O as the heat transport fluid in a packed bed thermocline is likely not a practical approach. The specific heat of the fluid is a strong function of the temperatures at values near 400 °C, and the temperature profile in the bed during a charging cycle is markedly different than the profile during a discharging cycle. 2) The use of supercritical CO2 as the heat transport fluid in a packed bed thermocline is judged to be technically feasible. Nonetheless, the high operating pressures for the supercritical fluid require the use of pressure vessels to contain the storage inventory. The unit cost of the two-tank nitrate salt system is approximately $24/kWht, while the unit cost of the high pressure thermocline system is nominally 10 times as high. 3) For the supercritical fluids, the outer crown temperatures of the receiver tubes are in the range of 700 to 800 °C. At temperatures of 700 °C and above

  10. Measurement of Coolant in a Flat Heat Pipe Using Neutron Radiography

    NASA Astrophysics Data System (ADS)

    Mizuta, Kei; Saito, Yasushi; Goshima, Takashi; Tsutsui, Toshio

    A newly developed flat heat pipe FGHPTM (Morex Kiire Co.) was experimentally investigated by using neutron radiography. The test sample of the FGHP heat spreader was 65 × 65 × 2 mm3 composed of several etched copper plates and pure water was used as the coolant. Neutron radiography was performed at the E-2 port of the Kyoto University Research Reactor (KUR). The coolant distributions in the wick area of the FGHP and its heat transfer characteristics were measured at heating conditions. Experimental results show that the coolant distributions depend slightly on its installation posture and that the liquid thickness in the wick region remains constant with increasing heat input to the FGHP. In addition, it is found that the wick surface does not dry out even in the vertical posture at present experimental conditions.

  11. System and method for determining coolant level and flow velocity in a nuclear reactor

    DOEpatents

    Brisson, Bruce William; Morris, William Guy; Zheng, Danian; Monk, David James; Fang, Biao; Surman, Cheryl Margaret; Anderson, David Deloyd

    2013-09-10

    A boiling water reactor includes a reactor pressure vessel having a feedwater inlet for the introduction of recycled steam condensate and/or makeup coolant into the vessel, and a steam outlet for the discharge of produced steam for appropriate work. A fuel core is located within a lower area of the pressure vessel. The fuel core is surrounded by a core shroud spaced inward from the wall of the pressure vessel to provide an annular downcomer forming a coolant flow path between the vessel wall and the core shroud. A probe system that includes a combination of conductivity/resistivity probes and/or one or more time-domain reflectometer (TDR) probes is at least partially located within the downcomer. The probe system measures the coolant level and flow velocity within the downcomer.

  12. Nanomaterials for efficiently lowering the freezing point of anti-freeze coolants.

    PubMed

    Hong, Haiping; Zheng, Yingsong; Roy, Walter

    2007-09-01

    In this paper, we report, for the first time, the effect of the lowered freezing point in a 50% water/50% anti-freeze coolant (PAC) or 50% water/50% ethylene glycol (EG) solution by the addition of carbon nanotubes and other particles. The experimental results indicated that the nano materials are much more efficient (hundreds fold) in lowering the freezing point than the regular ionic materials (e.g., NaCl). The possible explanation for this interesting phenomenon is the colligative property of fluid and relative small size of nano material. It is quite certain that the carbon nanotubes and metal oxide nano particles could be a wonderful candidate for the nano coolant application because they could not only increase the thermal conductivity, but also efficiently lower the freezing point of traditional coolants. PMID:18019146

  13. Carbothermic Aluminum Production Using Scrap Aluminum As A Coolant

    DOEpatents

    LaCamera, Alfred F.

    2002-11-05

    A process for producing aluminum metal by carbothermic reduction of alumina ore. Alumina ore is heated in the presence of carbon at an elevated temperature to produce an aluminum metal body contaminated with about 10-30% by wt. aluminum carbide. Aluminum metal or aluminum alloy scrap then is added to bring the temperature to about 900-1000.degree. C. and precipitate out aluminum carbide. The precipitated aluminum carbide is filtered, decanted, or fluxed with salt to form a molten body having reduced aluminum carbide content.

  14. A new microspore embryogenesis system under low temperature which mimics zygotic embryogenesis initials, expresses auxin and efficiently regenerates doubled-haploid plants in Brassica napus

    PubMed Central

    2012-01-01

    Background Microspore embryogenesis represents a unique system of single cell reprogramming in plants wherein a highly specialized cell, the microspore, by specific stress treatment, switches its fate towards an embryogenesis pathway. In Brassica napus, a model species for this phenomenon, incubation of isolated microspores at 32°C is considered to be a pre-requisite for embryogenesis induction. Results We have developed a new in vitro system at lower temperature (18°C) to efficiently induce microspore embryogenesis throughout two different developmental pathways: one involving the formation of suspensor-like structures (52.4%) and another producing multicellular embryos without suspensor (13.1%); additionally, a small proportion of non-responsive microspores followed a gametophytic-like development (34.4%) leading to mature pollen. The suspensor-like pathway followed at 18°C involved the establishment of asymmetric identities from the first microspore division and an early polarity leading to different cell fates, suspensor and embryo development, which were formed by cells with different organizations and endogenous auxin distribution, similar to zygotic embryogenesis. In addition, a new strategy for germination of microspore derived embryos was developed for achieving more than 90% conversion of embryos to plantlets, with a predominance of spontaneous doubled haploids plants. Conclusion The present work reveals a novel mechanism for efficient microspore embryogenesis induction in B. napus using continuous low temperature treatment. Results indicated that low temperature applied for longer periods favours an embryogenesis pathway whose first division originates asymmetric cell identities, early polarity establishment and the formation of suspensor-like structures, mimicking zygotic embryogenesis. This new in vitro system provides a convenient tool to analyze in situ the mechanisms underlying different developmental pathways during the microspore reprogramming

  15. Enhanced temperature and emission from a standoff 266 nm laser initiated LIBS plasma using a simultaneous 10.6 microm CO2 laser pulse.

    PubMed

    Pal, Avishekh; Waterbury, Robert D; Dottery, Edwin L; Killinger, Dennis K

    2009-05-25

    A deep UV 266 nm laser induced LIBS plasma has been enhanced by using a simultaneous 10.6 microm CO(2) laser pulse at standoff ranges up to 55 m for several targets including metals, ceramics and plastics. The LIBS plasma emission was produced, for the first time, by a 266 nm laser and was enhanced by several orders of magnitude using the CO(2) laser pulse. The temperature of the enhanced LIBS plasma was measured, for the first time, and was observed to increase by about 3000K due to the addition of the CO(2) laser pulse. PMID:19466135

  16. Fatigue crack initiation in carbon and low-alloy steels in light water reactor environments : mechanism and prediction.

    SciTech Connect

    Chopra, O. K.; Shack, W. J.

    1998-01-27

    Section 111 of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. The effects of reactor coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of light water reactor (LWR) coolant environments on the fatigue resistance of carbon and low-alloy steels. Under certain loading and environmental conditions, fatigue lives of test specimens may be shorter than those in air by a factor of {approx}70. The crack initiation and crack growth characteristics of carbon and low-alloy steels in LWR environments are presented. Decreases in fatigue life of these steels in high-dissolved-oxygen water are caused primarily by the effect of environment on growth of short cracks < 100 {micro}m in depth. The material and loading parameters that influence fatigue life in LWR environments are defined. Fatigue life is decreased significantly when five conditions are satisfied simultaneously, viz., applied strain range, service temperature, dissolved oxygen in water, and S content in steel are above a threshold level, and loading strain rate is below a threshold value. Statistical models have been developed for estimating the fatigue life of these steels in LWR environments. The significance of the effect of environment on the current Code design curve is evaluated.

  17. Handling interferences in ⁸⁹Sr and ⁹⁰Sr measurements of reactor coolant water: a method based on strontium separation chemistry.

    PubMed

    Holmgren, S; Tovedal, A; Jonsson, S; Nygren, U; Ramebäck, H

    2014-08-01

    Measurements for determining the activity of (89)Sr and (90)Sr in reactor coolant water are associated with limitations due to interferences from radionuclides with similar chemical properties and β(-)-energies. From a measurement bias point-of-view these interferences would result mainly in an overestimated activity concentration of (90)Sr. In order to address the interference problem, a common and well-known method was used in order to show the need for sufficient decontamination. An improvement was achieved by taking the sample through two initial strontium separations in order to increase the decontamination factor. This method determines the activity concentration of (89)Sr and (90)Sr, via its daughter nuclide (90)Y, by Cherenkov counting. This work is primarily based on theoretical calculations of strontium-, yttrium- and other potential interfering radionuclide ratios after instant fission. The work done to confirm the theoretical calculations were carried through on spiked strontium standard solutions and fresh reactor coolant water. The reactor coolant water was known to contain interferences at a composition resembling that of instant fission. The detection limit for double separation was calculated to 0.17 Bq/kg for (90)Sr and 0.38 Bq/kg for (89)Sr. When using methods that solely rely on strontium resins, this paper shows that the decontamination factor (DF) is significantly higher when using double separation than that of a single separation. The paper also shows that the DF of an initial double strontium separation is as effective when it comes to removing high ratio interferences as separations done with both Sr- and Ln-resin (EiChrom Technologies, Inc., 2003; Tovedal et al., 2009b). However, 'old' samples, where e.g. (140)Ba and (89)Sr has decayed, does not benefit from double separation. Furthermore, samples with low ratios of interfering radionuclides does not benefit from using this method either, seeing as this is a more time consuming method

  18. Development of a cleaning process for uranium chips machined with a glycol-water-borax coolant

    SciTech Connect

    Taylor, P.A.

    1984-12-01

    A chip-cleaning process has been developed to remove the new glycol-water-borax coolant from oralloy chips. The process involves storing the freshly cut chips in Freon-TDF until they are cleaned, washing with water, and displacing the water with Freon-TDF. The wash water can be reused many times and still yield clean chips and then be added to the coolant to make up for evaporative losses. The Freon-TDF will be cycled by evaporation. The cleaning facility is currently being designed and should be operational by April 1985.

  19. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D., Sr.

    1989-01-01

    A research program to study the effect of enhancement devices on flow boiling heat transfer in coolant channels, which are heated either from the top side or uniformly, is discussed. Freon 11 is the working fluid involved. The specific objectives are: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls, (2) examine the effect channel diameter (and the length-to-diameter aspect ratio) variations for the smooth wall channel, and (3) develop an improved data reduction analysis.

  20. TRAC loss-of-coolant accident analyses of the Savannah River production reactors

    SciTech Connect

    Lime, J.F.; Motley, F.E. )

    1990-06-01

    TRAC loss-of-coolant accident (LOCA) analyses were performed as part of the independent safety review of the US Department of Energy's Savannah River (SR) production reactors. The double-ended guillotine break in a coolant loop is a design-basis LOCA for the SR reactors. Three break locations were analyzed to determine the worst break location: (1) at the pump-suction flange; (2) at the pump discharge flange; or (3) at the plenum inlet. The plenum-inlet break was shown to be the most severe in terms of minimum flow delivered to each fuel assembly in the reactor core.