EBR-II high-ramp transients under computer control

International Nuclear Information System (INIS)

Forrester, R.J.; Larson, H.A.; Christensen, L.J.; Booty, W.F.; Dean, E.M.

1983-01-01

During reactor run 122, EBR-II was subjected to 13 computer-controlled overpower transients at ramps of 4 MWt/s to qualify the facility and fuel for transient testing of LMFBR oxide fuels as part of the EBR-II operational-reliability-testing (ORT) program. A computer-controlled automatic control-rod drive system (ACRDS), designed by EBR-II personnel, permitted automatic control on demand power during the transients

Deformation modeling and the strain transient dip test

International Nuclear Information System (INIS)

Jones, W.B.; Rohde, R.W.; Swearengen, J.C.

1980-01-01

Recent efforts in material deformation modeling reveal a trend toward unifying creep and plasticity with a single rate-dependent formulation. While such models can describe actual material deformation, most require a number of different experiments to generate model parameter information. Recently, however, a new model has been proposed in which most of the requisite constants may be found by examining creep transients brought about through abrupt changes in creep stress (strain transient dip test). The critical measurement in this test is the absence of a resolvable creep rate after a stress drop. As a consequence, the result is extraordinarily sensitive to strain resolution as well as machine mechanical response. This paper presents the design of a machine in which these spurious effects have been minimized and discusses the nature of the strain transient dip test using the example of aluminum. It is concluded that the strain transient dip test is not useful as the primary test for verifying any micromechanical model of deformation. Nevertheless, if a model can be developed which is verifiable by other experimentts, data from a dip test machine may be used to generate model parameters

Future Transient Testing of Advanced Fuels

Energy Technology Data Exchange (ETDEWEB)

Jon Carmack

2009-09-01

The transient in-reactor fuels testing workshop was held on May 4–5, 2009 at Idaho National Laboratory. The purpose of this meeting was to provide a forum where technical experts in transient testing of nuclear fuels could meet directly with technical instrumentation experts and nuclear fuel modeling and simulation experts to discuss needed advancements in transient testing to support a basic understanding of nuclear fuel behavior under off-normal conditions. The workshop was attended by representatives from Commissariat à l'Énergie Atomique CEA, Japanese Atomic Energy Agency (JAEA), Department of Energy (DOE), AREVA, General Electric – Global Nuclear Fuels (GE-GNF), Westinghouse, Electric Power Research Institute (EPRI), universities, and several DOE national laboratories. Transient testing of fuels and materials generates information required for advanced fuels in future nuclear power plants. Future nuclear power plants will rely heavily on advanced computer modeling and simulation that describes fuel behavior under off-normal conditions. TREAT is an ideal facility for this testing because of its flexibility, proven operation and material condition. The opportunity exists to develop advanced instrumentation and data collection that can support modeling and simulation needs much better than was possible in the past. In order to take advantage of these opportunities, test programs must be carefully designed to yield basic information to support modeling before conducting integral performance tests. An early start of TREAT and operation at low power would provide significant dividends in training, development of instrumentation, and checkout of reactor systems. Early start of TREAT (2015) is needed to support the requirements of potential users of TREAT and include the testing of full length fuel irradiated in the FFTF reactor. The capabilities provided by TREAT are needed for the development of nuclear power and the following benefits will be realized by

Future Transient Testing of Advanced Fuels

International Nuclear Information System (INIS)

Carmack, Jon

2009-01-01

The transient in-reactor fuels testing workshop was held on May 4-5, 2009 at Idaho National Laboratory. The purpose of this meeting was to provide a forum where technical experts in transient testing of nuclear fuels could meet directly with technical instrumentation experts and nuclear fuel modeling and simulation experts to discuss needed advancements in transient testing to support a basic understanding of nuclear fuel behavior under off-normal conditions. The workshop was attended by representatives from Commissariat energie Atomique CEA, Japanese Atomic Energy Agency (JAEA), Department of Energy (DOE), AREVA, General Electric - Global Nuclear Fuels (GE-GNF), Westinghouse, Electric Power Research Institute (EPRI), universities, and several DOE national laboratories. Transient testing of fuels and materials generates information required for advanced fuels in future nuclear power plants. Future nuclear power plants will rely heavily on advanced computer modeling and simulation that describes fuel behavior under off-normal conditions. TREAT is an ideal facility for this testing because of its flexibility, proven operation and material condition. The opportunity exists to develop advanced instrumentation and data collection that can support modeling and simulation needs much better than was possible in the past. In order to take advantage of these opportunities, test programs must be carefully designed to yield basic information to support modeling before conducting integral performance tests. An early start of TREAT and operation at low power would provide significant dividends in training, development of instrumentation, and checkout of reactor systems. Early start of TREAT (2015) is needed to support the requirements of potential users of TREAT and include the testing of full length fuel irradiated in the FFTF reactor. The capabilities provided by TREAT are needed for the development of nuclear power and the following benefits will be realized by the

Fuel-pin cladding transient failure strain criterion

International Nuclear Information System (INIS)

Bard, F.E.; Duncan, D.R.; Hunter, C.W.

1983-01-01

A criterion for cladding failure based on accumulated strain was developed for mixed uranium-plutonium oxide fuel pins and used to interpret the calculated strain results from failed transient fuel pin experiments conducted in the Transient Reactor Test (TREAT) facility. The new STRAIN criterion replaced a stress-based criterion that depends on the DORN parameter and that incorrectly predicted fuel pin failure for transient tested fuel pins. This paper describes the STRAIN criterion and compares its prediction with those of the stress-based criterion

Review of Transient Fuel Test Results at Sandia National Laboratories and the Potential for Future Fast Reactor Fuel Transient Testing in the Annular Core Research Reactor

Energy Technology Data Exchange (ETDEWEB)

Wright, Steven A.; Pickard, Paul S.; Parma, Edward J.; Vernon, Milton E.; Kelly, John; Tikare, Veena [Sandia National Laboratories, Org 6872 MS-1146, PO Box 5800 Albuquerque, New Mexico 87185 (United States)

2009-06-15

Reactor driven transient tests of fast reactor fuels may be required to support the development and certification of new fuels for Fast Reactors. The results of the transient fuel tests will likely be needed to support licensing and to provide validation data to support the safety case for a variety of proposed fast fuel types and reactors. In general reactor driven transient tests are used to identify basic phenomenology during reactor transients and to determine the fuel performance limits and margins to failure during design basis accidents such as loss of flow, loss of heat sink, and reactivity insertion accidents. This paper provides a summary description of the previous Sandia Fuel Disruption and Transient Axial Relocation tests that were performed in the Annular Core Research Reactor (ACRR) for the U.S. Nuclear Regulatory Commission almost 25 years ago. These tests consisted of a number of capsule tests and flowing gas tests that used fission heating to disrupt fresh and irradiated MOX fuel. The behavior of the fuel disruption, the generation of aerosols and the melting and relocation of fuel and cladding was recorded on high speed cinematography. This paper will present videos of the fuel disruption that was observed in these tests which reveal stark differences in fuel behavior between fresh and irradiated fuel. Even though these tests were performed over 25 years ago, their results are still relevant to today's reactor designs. These types of transient tests are again being considered by the Advanced Fuel Cycle Initiative to support the Global Nuclear Energy Partnership because of the need to perform tests on metal fuels and transuranic fuels. Because the Annular Core Research Reactor is the only transient test facility available within the US, a brief summary of Sandia's continued capability to perform these tests in the ACRR will also be provided. (authors)

First TREAT [Transient Reactor Test Facility] transient overpower tests on U-Pu-Zr fuel: M5 and M6

International Nuclear Information System (INIS)

Robinson, W.R.; Bauer, T.H.; Wright, A.E.; Rhodes, E.A.; Stanford, G.S.; Klickman, A.E.

1987-01-01

Transient Reactor Test Facility (TREAT) tests M5 and M6 were the first transient overpower (TOP) tests of the margin to cladding breach and prefailure elongation of metallic U-Pu-Zr ternary fuel, the reference fuel of the Integral Fast Reactor concept. Similar tests on U-Fs fueled EBR-II driver pins were previously performed and reported [1,2]. Results from these earlier tests indicated a margin to failure of about 4 times nominal power and significant axial elongation prior to failure, a feature that was very pronounced at low burnups. While these two fuel types are similar in many respects, the ternary alloy exhibits a much more complex physical structure and is typically irradiated at much higher temperatures. Thus, a prime motivation for performing M5 and M6 was to compare the safety related fuel performance characteristics of U-Fs and U-Pu-Zr. This report described conditions, results, and conclusions of testing of these fuel types

LMFBR. Off normal, transient test facilities and programs in the USA

International Nuclear Information System (INIS)

Herbst, R.J.

1985-01-01

The United States fast breeder reactor development program has included operational transient analyses and experiments to verify the predicted performance of core components. Operational transient testing has focused on off-normal operation during Plant Protection System terminated transient-overpower events. In-pile and out-of-pile tests have been used to simulate predicted thermal and mechanical strain cycles and measure component response. The spectrum of reactivity ramp rates investigated in TOP tests has recently been expanded to include rates of less than $0.1/s. These slow ramp rate studies are being done in cooperation with the Japanese. The US has also cooperated with the UK in the transient testing of Prototype Fast Reactor fuel pins

A review of experiments and results from the transient reactor test (TREAT) facility

International Nuclear Information System (INIS)

Deitrich, L. W.

1998-01-01

The TREAT Facility was designed and built in the late 1950s at Argonne National Laboratory to provide a transient reactor for safety experiments on samples of reactor fuels. It first operated in 1959. Throughout its history, experiments conducted in TREAT have been important in establishing the behavior of a wide variety of reactor fuel elements under conditions predicted to occur in reactor accidents ranging from mild off normal transients to hypothetical core disruptive accidents. For much of its history, TREAT was used primarily to test liquid-metal reactor fuel elements, initially for the Experimental Breeder Reactor-II (EBR-II), then for the Fast Flux Test Facility (FFTF), the Clinch River Breeder Reactor Plant (CRBRP), the British Prototype Fast Reactor (PFR), and finally, for the Integral Fast Reactor (IFR). Both oxide and metal elements were tested in dry capsules and in flowing sodium loops. The data obtained were instrumental in establishing the behavior of the fuel under off-normal and accident conditions, a necessary part of the safety analysis of the various reactors. In addition, TREAT was used to test light-water reactor (LWR) elements in a steam environment to obtain fission-product release data under meltdown conditions. Studies are now under way on applications of TREAT to testing of the behavior of high-burnup LWR elements under reactivity-initiated accident (RIA) conditions using a high-pressure water loop

Feasibility study on the transient fuel test loop installation

International Nuclear Information System (INIS)

Kim, J. Y.; Lee, C. Y.

1997-02-01

The design and installation of the irradiation test facility for verification test of the fuel performance are very important in connection with maximization of the utilization of HANARO. The objective of this study is to investigate and analyze the test capsules and loops in research reactors of the other countries and to design preliminarily the eligible transient fuel test facility to be installed in HANARO. The principle subjects of this study are to analyze the contents, kinds and scopes of the irradiation test facilities for nuclear technology development. The guidances for the basic and detail design of the transient fuel test facility in the future are presented. The investigation and analysis of various kinds of test facilities that are now in operation at the research reactors of nuclear advanced countries are carried out. Based on the design data of HANARO the design materials for an eligible transient fuel test facility comprises two pacts : namely, in pile test fuel in reactor core site, and out of pile system regulates the experimental conditions in the in pile test section. Especially for power ramping and cycling selection of the eligible power variation equipment in HANARO is carried out. (author). 13 refs., 4 tabs., 46 figs

Analysis of transients in the SRP test pile

International Nuclear Information System (INIS)

Church, J.P.

1976-11-01

Analysis of the hypothetical upper limit accident in the Savannah River Test Pile showed that the offsite thyroid dose from fission product release would be -3 of the 10-CFR-100 guideline dose for 95 percent of measured meteorological conditions. Offsite whole body dose would be negligible. The Test Pile was modified to limit the length of test piece that can be charged to the pile. These modifications reduce the potential offsite dose to -5 of the regulatory guidelines. Assessment of Test Pile safety included calculations of transients initiated by a variety of reactivity additions that were either terminated or not terminated by safety systems. Reactivity addition mechanisms considered were abnormally driving control rods out of the pile and charging abnormal test pieces into the pile. The transients were evaluated in the adiabatic approximation in which three-dimensional calculations of static flux shapes and reactivity were superimposed on point reactor kinetics calculations. Negative reactivity feedback effects appropriate for the pile and the temperature dependence of material properties, such as specific heat and thermal conductivity, were included. The results show that, for the worst initiators, safety systems can prevent the temperature rise from exceeding 1 0 C anywhere in the Test Pile. If the safety systems do not function, the pile temperatures will increase until the transient is ended by the inherent negative reactivity effects, including the melting of some fuel

On the intrinsic transient capability and limitations of solid oxide fuel cell systems

OpenAIRE

Mueller, F; Jabbari, F; Brouwer, J

2009-01-01

The intrinsic transient performance capability and limitation of integrated solid oxide fuel cell (SOFC) systems is evaluated based on the system balance-of-plant response and fuel cell operating requirements (i.e., allowable deviation from nominal operation). Specifically, non-dimensional relations are derived from conservation principles that quantify the maximum instantaneous current increase that a solid oxide fuel cell system can safely manage based on (1) the desired fuel cell operating...

Behavior of mixed-oxide fuel subjected to multiple thermal transients

International Nuclear Information System (INIS)

Fenske, G.R.; Hofman, G.L.; Neimark, L.A.; Poeppel, R.B.

1983-11-01

The microstructural behavior of irradiated mixed-oxide fuel subjected to multiple, mild thermal transients was investigated using direct electrical heating. The results demonstrate that significant intergranular porosity, accompanied by large-scale (>90%) release of the retained fission gas, developed as a result of the cyclic heating. Microstructural examination of the fuel indicated that thermal-shock-induced cracking of the fuel contributed significantly to the increased swelling and gas release

Behavior of mixed-oxide fuel subjected to multiple thermal transients

International Nuclear Information System (INIS)

Fenske, G.R.; Neimark, L.A.; Poeppel, R.B.; Hofman, G.L.

1985-01-01

The microstructural behavior of irradiated mixed-oxide fuel subjected to multiple, mild thermal transients was investigated using direct electrical heating. The results demonstrate that significant intergranular porosity, accompanied by large-scale (>90%) release of the retained fission gas, developed as a result of the cyclic heating. Microstructural examination of the fuel indicated that thermal-shock-induced cracking of the fuel contributed significantly to the increased swelling and gas release. 29 refs., 12 figs

Effect of transient scrotal hyperthermia on sperm parameters, seminal plasma biochemical markers, and oxidative stress in men

Directory of Open Access Journals (Sweden)

Meng Rao

2015-01-01

Full Text Available In this experimental prospective study, we aimed to analyze the effect of transient scrotal hyperthermia on the male reproductive organs, from the perspective of sperm parameters, semen plasma biochemical markers, and oxidative stress, to evaluate whether different frequencies of heat exposure cause different degrees of damage to spermatogenesis. Two groups of volunteers (10 per group received testicular warming in a 43°C water bath 10 times, for 30 min each time: group 1: 10 consecutive days; group 2: once every 3 days. Sperm parameters, epididymis and accessory sex gland function, semen plasma oxidative stress and serum sex hormones were tested before treatment and in the 16-week recovery period after treatment. At last, we found an obvious reversible decrease in sperm concentration (P = 0.005 for Group 1 and P= 0.008 for Group 2 when the minimums were compared with baseline levels, the same below, motility (P = 0.009 and 0.021, respectively, the hypoosmotic swelling test score (P = 0.007 and 0.008, respectively, total acrosin activity (P = 0.018 and 0.009, respectively, and an increase in the seminal plasma malondialdehyde concentration (P = 0.005 and 0.017, respectively. The decrease of sperm concentration was greater for Group 2 than for Group 1 (P = 0.031. We concluded that transient scrotal hyperthermia seriously, but reversibly, negatively affected the spermatogenesis, oxidative stress may be involved in this process. In addition, intermittent heat exposure more seriously suppresses the spermatogenesis compared to consecutive heat exposure. This may be indicative for clinical infertility etiology analysis and the design of contraceptive methods based on heat stress.

Comparing and characterizing transient and steady-state tests of the peripheral chemoreflex in humans.

Science.gov (United States)

Pfoh, Jamie R; Tymko, Michael M; Abrosimova, Maria; Boulet, Lindsey M; Foster, Glen E; Bain, Anthony R; Ainslie, Philip N; Steinback, Craig D; Bruce, Christina D; Day, Trevor A

2016-03-01

What is the central question of this study? We aimed to characterize the cardiorespiratory and cerebrovascular responses to transient and steady-state tests of the peripheral chemoreflex and to compare the hypoxic ventilatory responses (HVRs) between these tests. What is the main finding and its importance? The cardiovascular and cerebrovascular responses to transient tests were small in magnitude and short in duration. The steady-state isocapnic hypoxia test elicited a larger HVR than the transient 100% N(2) test, but the response magnitudes were correlated within individuals. The transient test of the HVR elicits fewer systemic effects than steady-state techniques and may have greater experimental utility than previously appreciated. Carotid chemoreceptors detect changes in arterial PO(2) and PCO(2), eliciting a peripheral chemoreflex (PCR). Steady-state (SS) hypoxia tests using dynamic end-tidal forcing (DEF) have been used to assess the hypoxic ventilatory response (HVR) but may be confounded by concomitant systemic effects. Transient tests of the PCR have also been developed but are not widely used, nor have the cardiovascular and cerebrovascular responses been characterized. We characterized the cardiorespiratory and cerebrovascular responses to transient tests of the PCR and compared the HVR between transient and SS-DEF tests. We hypothesized that the cardiovascular and cerebrovascular responses to the transient tests would be minimal and that the respiratory responses elicited from the transient and SS-DEF tests would be different in magnitude and not well correlated within individuals. Participants underwent five consecutive trials of two transient tests [three-breath 100% N(2) (TT-N(2)) and a single-breath 13% CO(2), in air] and two 10 min SS-DEF tests [isocapnic (SS-ISO) and poikilocapnic (SS-POI) hypoxia]. In response to the transient tests, heart rate, mean arterial pressure and the middle and posterior cerebral artery blood velocity increased (all P

TS-1 and TS-2 transient overpower tests on FFTF fuel

International Nuclear Information System (INIS)

Pitner, A.L.; Ferrell, P.C.; Culley, G.E.; Weber, E.T.

1985-01-01

The TS-1 and TS-2 TREAT transient experiments subjected a low burnup (2 MWd/kg) and a medium burnup (58 MWd/kg), respectively, FFTF irradiated fuel pin to unprotected 5 cents/s overpower transient conditions. The fuel pin failure response was similar in the two tests, which demonstrated a large margin to failure (P/P 0 > 3) and a favorable upper level failure location. Thus, for these transient conditions, burnup effects on transient performance appeared to be minimal in the range tested. Pin disruption in the medium burnup TS-2 test was more severe due to the higher fission gas pressurization, but failure occurred at only a 5% lower power level than for the low burnup TS-1 fuel pin. Both tests exhibited axial extrusion of molten fuel to the region above the fuel column several seconds before pin failure, demonstrating a potentially beneficial inherent safety mechanism to delay failure and mitigate accident consequences

Transient fuel and target performance testing for the HWR-NPR

International Nuclear Information System (INIS)

Jicha, J.J. Jr.

1990-01-01

This paper describes a five year program of fuel target transient performance testing and model development required for the safety assessment of the HWR new production reactor. Technical issues are described, focusing on fuel and target behavior during extremely low probability transients which can lead to fuel melting. Early work on these issues is reviewed. The program to meet remaining needs is described. Three major transient-testing activities are included: in-cell experiments on small samples of irradiated fuel and target, small-scale phenomenological experiments in the ACRR reactor, and limited-integral experiments in the TREAT reactor. A coordinated development of detailed fuel and target behavior models is also described

Alternatives Analysis for the Resumption of Transient Testing Program

Energy Technology Data Exchange (ETDEWEB)

Lee Nelson

2013-11-01

An alternatives analysis was performed for resumption of transient testing. The analysis considered eleven alternatives – including both US international facilities. A screening process was used to identify two viable alternatives from the original eleven. In addition, the alternatives analysis includes a no action alternative as required by the National Environmental Policy Act (NEPA). The alternatives considered in this analysis included: 1. Restart the Transient Reactor Test Facility (TREAT) 2. Modify the Annular Core Research Reactor (ACRR) which includes construction of a new hot cell and installation of a new hodoscope. 3. No Action

Data report of BWR post-CHF tests. Transient core thermal-hydraulic test program. Contract research

International Nuclear Information System (INIS)

Iguchi, Tadashi; Itoh, Hideo; Kiuchi, Toshio; Watanabe, Hironori; Kimura, Mamoru; Anoda, Yoshinari

2001-03-01

JAERI has been performing transient core thermal-hydraulic test program. In the program, authors performed BWR/ABWR DBE simulation tests with a test facility, which can simulate BWR/ABWR transients. The test facility has a 4 x 4 bundle core simulator with 15-rod heaters and one non-heated rod. Through the tests, authors quantified the thermal safety margin for core cooling. In order to quantify the thermal safety margin, authors collected experimental data on post-CHF. The data are essential for the evaluation of clad temperature transient when core heat-up occurs during DBEs. In comparison with previous post-CHF tests, present experiments were performed in much wider experimental condition, covering high clad temperature, low to high pressure and low to high mass flux. Further, data at wider elevation (lower to higher elevation of core) were obtained in the present experiments, which make possible to discuss the effect of axial position on thermal-hydraulics, while previous works usually discuss the thermal-hydraulics at the position where the first heat-up occurs. This data report describes test procedure, test condition and major experimental data of post-CHF tests. (author)

Ultrafast triggered transient energy storage by atomic layer deposition into porous silicon for integrated transient electronics

Science.gov (United States)

Douglas, Anna; Muralidharan, Nitin; Carter, Rachel; Share, Keith; Pint, Cary L.

2016-03-01

Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics.Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics. Electronic supplementary information (ESI) available: (i) Experimental details for ALD and material fabrication, ellipsometry film thickness, preparation of gel electrolyte and separator, details for electrochemical measurements, HRTEM image of VOx coated porous silicon, Raman spectroscopy for VOx as-deposited as well as annealed in air for 1 hour at 450 °C, SEM and transient behavior dissolution tests of uniformly coated VOx on

Transient deformational properties of high temperature alloys used in solid oxide fuel cell stacks

DEFF Research Database (Denmark)

Tadesse Molla, Tesfaye; Kwok, Kawai; Frandsen, Henrik Lund

2017-01-01

Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through...... to describe the high temperature inelastic deformational behaviors of Crofer 22 APU used for metallic interconnects in SOFC stacks.......Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through...... transients in operation including temporary shut downs. These stresses are highly affected by the transient creep behavior of metallic components in the SOFC stack. This study investigates whether a variation of the so-called Chaboche's unified power law together with isotropic hardening can represent...

Integrated, digital experiment transient control and safety protection of an in-pile test

International Nuclear Information System (INIS)

Thomas, R.W.; Whitacre, R.F.; Klingler, W.B.

1982-01-01

The Sodium Loop Safety Facility experimental program has demonstrated that in-pile loop fuel failure transient tests can be digitally controlled and protected with reliability and precision. This was done in four nuclear experiments conducted in the Engineering Test Reactor operated by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory. Loop sodium flow and reactor power transients can be programmed to sponsor requirements and verified prior to the test. Each controller has redundancy, which reduces the effect of single failures occurring during test transients. Feedback and reject criteria are included in the reactor power control. Timed sequencing integrates the initiation of the controllers, programmed safety set-points, and other experiment actions (e.g., planned scram). Off-line and on-line testing is included. Loss-of-flow, loss-of-piping-integrity, boiling-window, transient-overpower, and local fault tests have been successfully run using this system

Test system to simulate transient overpower LMFBR cladding failure

International Nuclear Information System (INIS)

Barrus, H.G.; Feigenbutz, L.V.

1981-01-01

One of the HEDL programs has the objective to experimentally characterize fuel pin cladding failure due to cladding rupture or ripping. A new test system has been developed which simulates a transient mechanically-loaded fuel pin failure. In this new system the mechanical load is prototypic of a fuel pellet rapidly expanding against the cladding due to various causes such as fuel thermal expansion, fuel melting, and fuel swelling. This new test system is called the Fuel Cladding Mechanical Interaction Mandrel Loading Test (FCMI/MLT). The FCMI/MLT test system and the method used to rupture cladding specimens very rapidly to simulate a transient event are described. Also described is the automatic data acquisition and control system which is required to control the startup, operation and shutdown of the very fast tests, and needed to acquire and store large quantities of data in a short time

Oxide-metal corium-concrete interaction test in the Vulcano facility

International Nuclear Information System (INIS)

Journeau, Ch.; Piluso, P.; Haquet, J.F.; Saretta, S.; Boccaccio, E.; Bonnet, J.M.

2007-01-01

Corium is likely to melt through the vessel and interact with the reactor pit concrete. Corium is made of a UO 2 -rich oxidic part, in which most of the decay heat is dissipated, and of a metallic part, mainly molten steel. An experiment has been set up in the Vulcano facility in which oxidic and metallic mixtures are molten in separate furnaces and poured in a concrete cavity. Induction heating is provided to the pool upper part thanks to shielding coils, so that, in case of stratification, the lighter oxidic corium-concrete mixture receives most of the power. Pre-calculations with the TOLBIAC-ICB corium-concrete interaction code based on the phase segregation model have provided valuable information for the dimensioning of this test: a thick metallic layer (>10 kg or 4 cm) has been chosen in order to obtain significant cavity ablation profiles depending on the selected heat transfer and stratification models. Stratification of the two liquid phases is predicted to occur in less than 10 minutes. In September 2006, the experiment was performed in the Vulcano facility. The corium was made of about 15 kg of steel at 1700 C and 30 kg of oxides (70% UO 2 , 16 % ZrO 2 and 14% concrete load) above 2000 C. It was poured in a limestone-rich concrete. This concrete type was selected for the first test, since the ablation is isotropic except for the initial transient, during oxidic corium-concrete interaction tests. 32 kW of induction power have been provided to the pool during the 4-hour test. The destruction of in-concrete thermocouples indicates that ablation was first mainly radial then became isotropic. This is quite similar to the ablation progression observed during previous tests with oxidic corium interacting with this type of concrete. Important 'volcanic activity' has been observed at the corium pool surface, compared to the previous oxidic corium experiments at Vulcano. (authors)

Oxide-metal corium-concrete interaction test in the Vulcano facility

Energy Technology Data Exchange (ETDEWEB)

Journeau, Ch.; Piluso, P.; Haquet, J.F.; Saretta, S.; Boccaccio, E.; Bonnet, J.M. [CEA Cadarache, Severe Accident Mastery experimental Lab. (DEN/DTN/STRI/LMA), 13 - Saint Paul lez Durance (France)

2007-07-01

Corium is likely to melt through the vessel and interact with the reactor pit concrete. Corium is made of a UO{sub 2}-rich oxidic part, in which most of the decay heat is dissipated, and of a metallic part, mainly molten steel. An experiment has been set up in the Vulcano facility in which oxidic and metallic mixtures are molten in separate furnaces and poured in a concrete cavity. Induction heating is provided to the pool upper part thanks to shielding coils, so that, in case of stratification, the lighter oxidic corium-concrete mixture receives most of the power. Pre-calculations with the TOLBIAC-ICB corium-concrete interaction code based on the phase segregation model have provided valuable information for the dimensioning of this test: a thick metallic layer (>10 kg or 4 cm) has been chosen in order to obtain significant cavity ablation profiles depending on the selected heat transfer and stratification models. Stratification of the two liquid phases is predicted to occur in less than 10 minutes. In September 2006, the experiment was performed in the Vulcano facility. The corium was made of about 15 kg of steel at 1700 C and 30 kg of oxides (70% UO{sub 2}, 16 % ZrO{sub 2} and 14% concrete load) above 2000 C. It was poured in a limestone-rich concrete. This concrete type was selected for the first test, since the ablation is isotropic except for the initial transient, during oxidic corium-concrete interaction tests. 32 kW of induction power have been provided to the pool during the 4-hour test. The destruction of in-concrete thermocouples indicates that ablation was first mainly radial then became isotropic. This is quite similar to the ablation progression observed during previous tests with oxidic corium interacting with this type of concrete. Important 'volcanic activity' has been observed at the corium pool surface, compared to the previous oxidic corium experiments at Vulcano. (authors)

40 CFR Appendix E to Subpart S of... - Transient Test Driving Cycle

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Transient Test Driving Cycle E Appendix... Driving Cycle (I) Driver's trace. All excursions in the transient driving cycle shall be evaluated by the... shall cause a test to be void. In addition, provisions shall be available to utilize cycle validation...

40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What transient duty cycles apply for... Procedures § 1048.510 What transient duty cycles apply for laboratory testing? (a) Starting with the 2007 model year, measure emissions by testing the engine on a dynamometer with the duty cycle described in...

Electronically controlled mechanical seal for aerospace applications--Part 2: Transient tests

Science.gov (United States)

Wolff, Paul J.; Salant, Richard F.

1995-01-01

An electronically controlled mechanical seal for use as the purge gas seal in a liquid oxygen turbopump has been fabricated and tested under transient operating conditions. The thickness of the lubricating film is controlled by adjusting the coning of the carbon face. This is accomplished by applying a voltage to a piezoelectric actuator to which the carbon face is bonded. The seal has been operated with a closed-loop control system that utilizes either the leakage rate or seal face temperature as the feedback. Both speed and pressure transients have been imposed on the seal. The transient tests have demonstrated that the seal is capable of maintaing low leakage rates while limiting face temperatures.

Manual for operation of the multipurpose thermalhydraulic test facility TOPFLOW (Transient Two Phase Flow Test Facility)

International Nuclear Information System (INIS)

Beyer, M.; Carl, H.; Schuetz, H.; Pietruske, H.; Lenk, S.

2004-07-01

The Forschungszentrum Rossendorf (FZR) e. V. is constructing a new large-scale test facility, TOPFLOW, for thermalhydraulic single effect tests. The acronym stands for transient two phase flow test facility. It will mainly be used for the investigation of generic and applied steady state and transient two phase flow phenomena and the development and validation of models of computational fluid dynamic (CFD) codes. The manual of the test facility must always be available for the staff in the control room and is restricted condition during operation of personnel and also reconstruction of the facility. (orig./GL)

40 CFR 1039.510 - Which duty cycles do I use for transient testing?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Which duty cycles do I use for... ENGINES Test Procedures § 1039.510 Which duty cycles do I use for transient testing? (a) Measure emissions by testing the engine on a dynamometer with one of the following transient duty cycles to determine...

Characterizing hydraulic fractures in shale gas reservoirs using transient pressure tests

Directory of Open Access Journals (Sweden)

Cong Wang

2015-06-01

This work presents an unconventional gas reservoir simulator and its application to quantify hydraulic fractures in shale gas reservoirs using transient pressure data. The numerical model incorporates most known physical processes for gas production from unconventional reservoirs, including two-phase flow of liquid and gas, Klinkenberg effect, non-Darcy flow, and nonlinear adsorption. In addition, the model is able to handle various types and scales of fractures or heterogeneity using continuum, discrete or hybrid modeling approaches under different well production conditions of varying rate or pressure. Our modeling studies indicate that the most sensitive parameter of hydraulic fractures to early transient gas flow through extremely low permeability rock is actually the fracture-matrix contacting area, generated by fracturing stimulation. Based on this observation, it is possible to use transient pressure testing data to estimate the area of fractures generated from fracturing operations. We will conduct a series of modeling studies and present a methodology using typical transient pressure responses, simulated by the numerical model, to estimate fracture areas created or to quantity hydraulic fractures with traditional well testing technology. The type curves of pressure transients from this study can be used to quantify hydraulic fractures in field application.

Transient testing of the FFTF for decay-heat removal by natural convection

International Nuclear Information System (INIS)

Beaver, T.R.; Johnson, H.G.; Stover, R.L.

1982-06-01

This paper reports on the series of transient tests performed in the FFTF as a major part of the pre-operations testing program. The structure of the transient test program was designed to verify the capability of the FFTF to safely remove decay heat by natural convection. The series culminated in a scram from full power to complete natural convection in the plant, simulating a loss of all electrical power. Test results and acceptance criteria related to the verification of safe decay heat removal are presented

Effect of pressure on the transient swelling rate of oxide fuel

International Nuclear Information System (INIS)

Gruber, E.E.

1982-04-01

An analysis of the transient swelling rate of oxide fuel, based on fission-gas bubble conditions calculated with the FRAS3 code, has been developed and implemented in the code. The need for this capability arises in the coupling of the FRAS3 fission-gas analysis code to the FPIN fuel-pin mechanics code. An efficient means of closely coupling the calculations of swelling strains and stresses between the modules is required. The present analysis provides parameters that allow the FPIN calculation to proceed through a fairly large time step, using estimated swelling rates, to calculate the stresses. These stress values can then be applied in the FRAS3 detailed calculation to refine the swelling calculation, and to provide new values for the parameters to estimate the swelling in the next time step. The swelling rates were calculated for two representative transients and used to estimate swelling over a short time period for various stress levels

Oxidation effects during corium melt in-vessel retention

Energy Technology Data Exchange (ETDEWEB)

Almyashev, V.I.; Granovsky, V.S.; Khabensky, V.B.; Krushinov, E.V.; Sulatsky, A.A.; Vitol, S.A. [Alexandrov Scientific-Research Institute of Technology (NITI), Sosnovy Bor (Russian Federation); Gusarov, V.V. [Ioffe Institute, St. Petersburg (Russian Federation); Bechta, S. [Royal Institute of Technology (KHT), Stockholm (Sweden); Barrachin, M.; Fichot, F. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), St Paul lez Durance (France); Bottomley, P.D., E-mail: paul.bottomley@ec.europa.eu [Joint Research Centre, Institut für Transurane (ITU), Karlsruhe (Germany); Fischer, M. [AREVA GmbH, Erlangen (Germany); Piluso, P. [CEA Cadarache-DEN/DTN/STRI (France)

2016-08-15

Highlights: • Corium–steel interaction tests were re-examined particularly for transient processes. • Oxidation of corium melt was sensitive to oxidant supply and surface characteristics. • Consequences for vessel steel corrosion rates in severe accidents were discussed. - Abstract: In the in-vessel corium retention studies conducted on the Rasplav-3 test facility within the ISTC METCOR-P project and OECD MASCA program, experiments were made to investigate transient processes taking place during the oxidation of prototypic molten corium. Qualitative and quantitative data have been produced on the sensitivity of melt oxidation rate to the type of oxidant, melt composition, molten pool surface characteristics. The oxidation rate is a governing factor for additional heat generation and hydrogen release; also for the time of secondary inversion of oxidic and metallic layers of corium molten pool.

Geometrical considerations in the transient ionization testing of digital logic circuits

International Nuclear Information System (INIS)

Johnston, A.

1982-01-01

Mechanisms are identified that can cause the transient response of digital logic circuits to depend on the logic state in which they are irradiated. Several of these mechanisms depend on surface topology, and for these cases the sensitive logic states can be determined by examining the topology. General approaches for transient radiation testing are also discussed for several MSI and LSI device technologies

Parametric Thermal Models of the Transient Reactor Test Facility (TREAT)

Energy Technology Data Exchange (ETDEWEB)

Bradley K. Heath

2014-03-01

This work supports the restart of transient testing in the United States using the Department of Energy’s Transient Reactor Test Facility at the Idaho National Laboratory. It also supports the Global Threat Reduction Initiative by reducing proliferation risk of high enriched uranium fuel. The work involves the creation of a nuclear fuel assembly model using the fuel performance code known as BISON. The model simulates the thermal behavior of a nuclear fuel assembly during steady state and transient operational modes. Additional models of the same geometry but differing material properties are created to perform parametric studies. The results show that fuel and cladding thermal conductivity have the greatest effect on fuel temperature under the steady state operational mode. Fuel density and fuel specific heat have the greatest effect for transient operational model. When considering a new fuel type it is recommended to use materials that decrease the specific heat of the fuel and the thermal conductivity of the fuel’s cladding in order to deal with higher density fuels that accompany the LEU conversion process. Data on the latest operating conditions of TREAT need to be attained in order to validate BISON’s results. BISON’s models for TREAT (material models, boundary convection models) are modest and need additional work to ensure accuracy and confidence in results.

Fission gas behavior during fast thermal transients

International Nuclear Information System (INIS)

Esteves, R.G.

1976-01-01

The behavior of non-equilibrium fission in fuel elements undergoing fast thermal transients is analyzed. To facilitate the analysis, a new variable, the equilibrium variable (EV) is defined. This variable, together with bubble radius, completely specifies a bubble with respect to its size and equilibrium condition. The analysis is coded using a two-variable (radius and EV) multigroup numerical approximation that accepts as input the time-temperature history, the time-fission rate history, and the time-thermal gradient history of the fuel element. Studies were performed to test the code for convergence with respect to the time interval and the number of groups chosen. For a series of transient simulation studies, the measurements obtained at HEDL (microscopic examination of intragranular porosity in oxide fuel transient-tested in TREAT) are used. Two different transient histories were selected; the first, a high-temperature transient (HTT) with a peak at 2477 0 K and the second, a low-temperature transient (LTT) with a peak-temperature at 2000 0 K. The LTT was simulated for three different conditions: Bubbles were allowed to move via (a) only biased migration, (b) via random migration, and (c) via both mechanisms. The HTT was also run for both mechanisms. The agreement with HEDL microscopic observations was fair for bubbles smaller than 964 A in diameter, and poor for larger bubbles. Bubbles that grew during the heat-up part of the transient were frozen at a larger size during the cool down

RELAP5 Prediction of Transient Tests in the RD-14 Test Facility

International Nuclear Information System (INIS)

Lee, Sukho; Kim, Manwoong; Kim, Hho-Jung; Lee, John C.

2005-01-01

Although the RELAP5 computer code has been developed for best-estimate transient simulation of a pressurized water reactor and its associated systems, it could not assess the thermal-hydraulic behavior of a Canada deuterium uranium (CANDU) reactor adequately. However, some studies have been initiated to explore the applicability for simulating a large-break loss-of-coolant accident in CANDU reactors. In the present study, the small-reactor inlet header break test and the steam generator secondary-side depressurization test conducted in the RD-14 test facility were simulated with the RELAP5/MOD3.2.2 code to examine its extended capability for all the postulated transients and accidents in CANDU reactors. The results were compared with experimental data and those of the CATHENA code performed by Atomic Energy of Canada Limited.In the RELAP5 analyses, the heated sections in the facility were simulated as a multichannel with five pipe models, which have identical flow areas and hydraulic elevations, as well as a single-pipe model.The results of the small-reactor inlet header break and the steam generator secondary-side depressurization simulations predicted experimental data reasonably well. However, some discrepancies in the depressurization of the primary heat transport system after the header break and consequent time delay of the major phenomena were observed in the simulation of the small-reactor inlet header break test

Effects of transient conditions on exhaust emissions from two non-road diesel engines

International Nuclear Information System (INIS)

Lindgren, M.; Hansson, P.-A.

2004-01-01

Growing interest in quantifying and reducing the amount of engine emissions of carbon monoxide, hydrocarbons, and nitrogen oxides loading the environment has led to increasingly tighter environmental regulations. However, current non-road emission standards are performed according to a steady-state test cycle, which does not include transient effects and thus underestimates the amount of emissions produced in real use of the engine. This study quantifies the effects of transients in engine speed and torque on the fuel consumption and emissions from two diesel engines intended for non-road mobile machinery. Fuel consumption and emissions from the engines were measured in an engine dynamometer during various transient load conditions. The results showed that during fast transients, the measured fuel consumption was up to twice as high as the corresponding steady-state load conditions. The effects of transients on emissions of nitrogen oxides were even greater, as were the effects of transient load increase with increasing transient conditions i. e. rate of change. The results showed that the effect of transients on fuel consumption and emissions were also dependent on the type of diesel injection pump and the engine equipment used. Furthermore, the results indicated that the air/fuel ratio was an important contributor to the emission formation process during transient loads. (Author)

Multiscale Transient and Steady-State Study of the Influence of Microstructure Degradation and Chromium Oxide Poisoning on Solid Oxide Fuel Cell Cathode Performance

Science.gov (United States)

Li, Guanchen; von Spakovsky, Michael R.; Shen, Fengyu; Lu, Kathy

2018-01-01

Oxygen reduction in a solid oxide fuel cell cathode involves a nonequilibrium process of coupled mass and heat diffusion and electrochemical and chemical reactions. These phenomena occur at multiple temporal and spatial scales, making the modeling, especially in the transient regime, very difficult. Nonetheless, multiscale models are needed to improve the understanding of oxygen reduction and guide cathode design. Of particular importance for long-term operation are microstructure degradation and chromium oxide poisoning both of which degrade cathode performance. Existing methods are phenomenological or empirical in nature and their application limited to the continuum realm with quantum effects not captured. In contrast, steepest-entropy-ascent quantum thermodynamics can be used to model nonequilibrium processes (even those far-from equilibrium) at all scales. The nonequilibrium relaxation is characterized by entropy generation, which can unify coupled phenomena into one framework to model transient and steady behavior. The results reveal the effects on performance of the different timescales of the varied phenomena involved and their coupling. Results are included here for the effects of chromium oxide concentrations on cathode output as is a parametric study of the effects of interconnect-three-phase-boundary length, oxygen mean free path, and adsorption site effectiveness. A qualitative comparison with experimental results is made.

A novel approach to model the transient behavior of solid-oxide fuel cell stacks

Science.gov (United States)

Menon, Vikram; Janardhanan, Vinod M.; Tischer, Steffen; Deutschmann, Olaf

2012-09-01

This paper presents a novel approach to model the transient behavior of solid-oxide fuel cell (SOFC) stacks in two and three dimensions. A hierarchical model is developed by decoupling the temperature of the solid phase from the fluid phase. The solution of the temperature field is considered as an elliptic problem, while each channel within the stack is modeled as a marching problem. This paper presents the numerical model and cluster algorithm for coupling between the solid phase and fluid phase. For demonstration purposes, results are presented for a stack operated on pre-reformed hydrocarbon fuel. Transient response to load changes is studied by introducing step changes in cell potential and current. Furthermore, the effect of boundary conditions and stack materials on response time and internal temperature distribution is investigated.

TRAC-PF1 analysis of LOFT steam-generator feedwater transient test L9-1

International Nuclear Information System (INIS)

Meier, J.K.

1983-01-01

The Transient Reactor Analysis Code (TRAC-PF1) calculations were compared to test data from Loss-of-Fluid Test (LOFT) L9-1, which was a loss-of-feedwater transient. This paper includes descriptions of the test and the TRAC input and compares the TRAC-calculated results with the test data. We conclude that the code predicted the experiment well, given the uncertainties in the boundary conditions. The analysis indicates the need to model all the flow paths and heat structures, and to improve the TRAC wall condensation heat-transfer model

Global nuclear energy partnership fuels transient testing at the Sandia National Laboratories nuclear facilities : planning and facility infrastructure options

International Nuclear Information System (INIS)

Kelly, John E.; Wright, Steven Alan; Tikare, Veena; MacLean, Heather J.; Parma, Edward J.Jr; Peters, Curtis D.; Vernon, Milton E.; Pickard, Paul S.

2007-01-01

The Global Nuclear Energy Partnership fuels development program is currently developing metallic, oxide, and nitride fuel forms as candidate fuels for an Advanced Burner Reactor. The Advance Burner Reactor is being designed to fission actinides efficiently, thereby reducing the long-term storage requirements for spent fuel repositories. Small fuel samples are being fabricated and evaluated with different transuranic loadings and with extensive burnup using the Advanced Test Reactor. During the next several years, numerous fuel samples will be fabricated, evaluated, and tested, with the eventual goal of developing a transmuter fuel database that supports the down selection to the most suitable fuel type. To provide a comparative database of safety margins for the range of potential transmuter fuels, this report describes a plan to conduct a set of early transient tests in the Annular Core Research Reactor at Sandia National Laboratories. The Annular Core Research Reactor is uniquely qualified to perform these types of tests because of its wide range of operating capabilities and large dry central cavity which extents through the center of the core. The goal of the fuels testing program is to demonstrate that the design and fabrication processes are of sufficient quality that the fuel will not fail at its design limit--up to a specified burnup, power density, and operating temperature. Transient testing is required to determine the fuel pin failure thresholds and to demonstrate that adequate fuel failure margins exist during the postulated design basis accidents

Global nuclear energy partnership fuels transient testing at the Sandia National Laboratories nuclear facilities : planning and facility infrastructure options.

Energy Technology Data Exchange (ETDEWEB)

Kelly, John E.; Wright, Steven Alan; Tikare, Veena; MacLean, Heather J. (Idaho National Laboratory, Idaho Falls, ID); Parma, Edward J., Jr.; Peters, Curtis D.; Vernon, Milton E.; Pickard, Paul S.

2007-10-01

The Global Nuclear Energy Partnership fuels development program is currently developing metallic, oxide, and nitride fuel forms as candidate fuels for an Advanced Burner Reactor. The Advance Burner Reactor is being designed to fission actinides efficiently, thereby reducing the long-term storage requirements for spent fuel repositories. Small fuel samples are being fabricated and evaluated with different transuranic loadings and with extensive burnup using the Advanced Test Reactor. During the next several years, numerous fuel samples will be fabricated, evaluated, and tested, with the eventual goal of developing a transmuter fuel database that supports the down selection to the most suitable fuel type. To provide a comparative database of safety margins for the range of potential transmuter fuels, this report describes a plan to conduct a set of early transient tests in the Annular Core Research Reactor at Sandia National Laboratories. The Annular Core Research Reactor is uniquely qualified to perform these types of tests because of its wide range of operating capabilities and large dry central cavity which extents through the center of the core. The goal of the fuels testing program is to demonstrate that the design and fabrication processes are of sufficient quality that the fuel will not fail at its design limit--up to a specified burnup, power density, and operating temperature. Transient testing is required to determine the fuel pin failure thresholds and to demonstrate that adequate fuel failure margins exist during the postulated design basis accidents.

HEDL W-1 SLSF experiment LOPI transient and boiling test results

International Nuclear Information System (INIS)

Henderson, J.M.; Wood, S.A.; Rothrock, R.B.

1980-01-01

The W-1 Sodium Loop Safety Facility (SLSF) experiment was designed to study the heat release characteristics of fast reactor fuel pins under Loss-of-Piping-Integrity (LOPI) accident conditions and determine stable sodium boiling initiation and recovery limits in a prototypic fuel pin bundle array. The results of the experiment address major second level of assurance (LOA-2) safety issues and provide increased insight and understanding of phenomena that would inherently terminate hypothesized accidents with only limited core damage. The irradiation phase of the experiment, consisting of thirteen individual transients, was performed between May 27 and July 20, 1979. The final transient produced approximately two seconds of coolant boiling, cladding dryout, and incipient fuel pin failure. The facility and test hardware performed as designed, allowing completion of all planned tests and achievement of all test objectives

CANDU fuel behaviour under transient conditions

International Nuclear Information System (INIS)

Segel, A.W.L.

1979-04-01

The Canadian R and D program to understand CANDU fuel behaviour under transient conditions is described. Fuel sheath behaviour studies have led to the development of a model of transient plastic strain in inert gas, which integrates the deformation due to several mechanisms. Verification tests demonstrated that on average the model overpredicts strain by 20%. From oxidation kinetics studies a sheath failure embrittlement criterion based on oxygen distribution has been developed. We have also established a rate equation for high-temperature stress-dependent crack formation due to embrittlement of the sheath by beryllium. An electric, simulated fuel element is being used in laboratory tests to characterize the behaviour of fuel in the horizontal. In-reactor, post-dryout tests have been done for several years. There is an axially-segmented, axisymmetric fuel element model in place and a fully two-dimensional code is under development. Laboratory testing of bundles, in its early stages, deals with the effects of geometric distortion and sheath-to-sheath interaction. In-reactor, post-dryout tests of CANDU fuel bundles with extensive central UO 2 melting did not result in fuel fragmentation nor damage to the pressure tube. (author)

Addressing the selectivity issue of cobalt doped zinc oxide thin film iso-butane sensors: Conductance transients and principal component analyses

Science.gov (United States)

Ghosh, A.; Majumder, S. B.

2017-07-01

Iso-butane (i-C4H10) is one of the major components of liquefied petroleum gas which is used as fuel in domestic and industrial applications. Developing chemi-resistive selective i-C4H10 thin film sensors remains a major challenge. Two strategies were undertaken to differentiate carbon monoxide, hydrogen, and iso-butane gases from the measured conductance transients of cobalt doped zinc oxide thin films. Following the first strategy, the response and recovery transients of conductances in these gas environments are fitted using the Langmuir adsorption kinetic model to estimate the heat of adsorption, response time constant, and activation energies for adsorption (response) and desorption (recovery). Although these test gases have seemingly different vapor densities, molecular diameters, and reactivities, analyzing the estimated heat of adsorption and activation energies (for both adsorption and desorption), we could not differentiate these gases unequivocally. However, we have found that the lower the vapor density, the faster the response time irrespective of the test gas concentration. As a second strategy, we demonstrated that feature extraction of conductance transients (using fast Fourier transformation) in conjunction with the pattern recognition algorithm (principal component analysis) is more fruitful to address the cross-sensitivity of Co doped ZnO thin film sensors. We have found that although the dispersion among different concentrations of hydrogen and carbon monoxide could not be avoided, each of these three gases forms distinct clusters in the plot of principal component 2 versus 1 and therefore could easily be differentiated.

Evaluation of a Ductility after High Temperature Oxidation with the Three-Point Bend Test in Zirconium Alloys

International Nuclear Information System (INIS)

Jung, Yang Il; Park, Sang Yoon; Park, Jeong Yong; Jeong, Yong Hwan

2010-01-01

In a light water reactor, the fuel cladding play an important role of preventing leakage of radioactive materials into the coolant, and thus the mechanical integrity of the cladding should be guaranteed under the conditions of normal and transient operation. In the case of a loss of coolant accident (LOCA), the cladding is subjected to a high temperature oxidation which is finally quenched because of an emergency coolant reflooding into the core. In this situation, the current LOCA criteria consist of five separate requirements: i) peak cladding temperature, ii) maximum cladding oxidation, iii) maximum hydrogen generation, iv) coolable geometry, and v) long-term cooling. The claddings lose their ductility due to the microstructural phase transformation from beta to martensite alpha-prime. and hydrogen up-take after LOCA. Since the reduction in ductility can induce embrittlement of claddings, post-quench ductility is one of the major concerns in transient operation circumstances. For the analysis, usually ring compression test are performed on ring samples cut from the tube to examine the oxidized cladding ductility. However, the test would not be applicable to the platelet samples which are general form of a specimen for developing alloys. As a high burn-up fuel cladding materials, Zircaloys are being replaced by modern zirconium alloys such as ZIRLO, and M5. Korea has also developed a new fuel cladding material HANA (high performance alloy for nuclear application) by the Korea Atomic Energy Research Institute. Because of the different composition of the newer claddings in comparison with the conventional Zircaloy-4, the high temperature oxidation behavior and the ductility after the oxidation would be different, and the properties should be evaluated how much the newer claddings were improved

STEADY STATE MODELING OF THE MINIMUM CRITICAL CORE OF THE TRANSIENT REACTOR TEST FACILITY

Energy Technology Data Exchange (ETDEWEB)

Anthony L. Alberti; Todd S. Palmer; Javier Ortensi; Mark D. DeHart

2016-05-01

With the advent of next generation reactor systems and new fuel designs, the U.S. Department of Energy (DOE) has identified the need for the resumption of transient testing of nuclear fuels. The DOE has decided that the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) is best suited for future testing. TREAT is a thermal neutron spectrum, air-cooled, nuclear test facility that is designed to test nuclear fuels in transient scenarios. These specific scenarios range from simple temperature transients to full fuel melt accidents. DOE has expressed a desire to develop a simulation capability that will accurately model the experiments before they are irradiated at the facility. It is the aim for this capability to have an emphasis on effective and safe operation while minimizing experimental time and cost. The multi physics platform MOOSE has been selected as the framework for this project. The goals for this work are to identify the fundamental neutronics properties of TREAT and to develop an accurate steady state model for future multiphysics transient simulations. In order to minimize computational cost, the effect of spatial homogenization and angular discretization are investigated. It was found that significant anisotropy is present in TREAT assemblies and to capture this effect, explicit modeling of cooling channels and inter-element gaps is necessary. For this modeling scheme, single element calculations at 293 K gave power distributions with a root mean square difference of 0.076% from those of reference SERPENT calculations. The minimum critical core configuration with identical gap and channel treatment at 293 K resulted in a root mean square, total core, radial power distribution 2.423% different than those of reference SERPENT solutions.

Test Concept for Advanced Oxidation Techniques

DEFF Research Database (Denmark)

Bennedsen, Lars Rønn; Søgaard, Erik Gydesen; Mortensen, Lars

advanced on-site oxidation tests. The remediation techniques included are electrochemical oxidation, photochemical/photocatalytic oxidation, ozone, hydrogen peroxide, permanganate, and persulfate among others. A versatile construction of the mobile test unit makes it possible to combine different...

Chronic Iron Limitation Confers Transient Resistance to Oxidative Stress in Marine Diatoms.

Science.gov (United States)

Graff van Creveld, Shiri; Rosenwasser, Shilo; Levin, Yishai; Vardi, Assaf

2016-10-01

Diatoms are single-celled, photosynthetic, bloom-forming algae that are responsible for at least 20% of global primary production. Nevertheless, more than 30% of the oceans are considered "ocean deserts" due to iron limitation. We used the diatom Phaeodactylum tricornutum as a model system to explore diatom's response to iron limitation and its interplay with susceptibility to oxidative stress. By analyzing physiological parameters and proteome profiling, we defined two distinct phases: short-term (chronic (>5 d, phase II) iron limitation. While at phase I no significant changes in physiological parameters were observed, molecular markers for iron starvation, such as Iron Starvation Induced Protein and flavodoxin, were highly up-regulated. At phase II, down-regulation of numerous iron-containing proteins was detected in parallel to reduction in growth rate, chlorophyll content, photosynthetic activity, respiration rate, and antioxidant capacity. Intriguingly, while application of oxidative stress to phase I and II iron-limited cells similarly oxidized the reduced glutathione (GSH) pool, phase II iron limitation exhibited transient resistance to oxidative stress, despite the down regulation of many antioxidant proteins. By comparing proteomic profiles of P. tricornutum under iron limitation and metatranscriptomic data of an iron enrichment experiment conducted in the Pacific Ocean, we propose that iron-limited cells in the natural environment resemble the phase II metabolic state. These results provide insights into the trade-off between optimal growth rate and susceptibility to oxidative stress in the response of diatoms to iron quota in the marine environment. © 2016 American Society of Plant Biologists. All Rights Reserved.

Complete suppression of boron transient-enhanced diffusion and oxidation-enhanced diffusion in silicon using localized substitutional carbon incorporation

Science.gov (United States)

Carroll, M. S.; Chang, C.-L.; Sturm, J. C.; Büyüklimanli, T.

1998-12-01

In this letter, we show the ability, through introduction of a thin Si1-x-yGexCy layer, to eliminate the enhancement of enhanced boron diffusion in silicon due to an oxidizing surface or ion implant damage. This reduction of diffusion is accomplished through a low-temperature-grown thin epitaxial Si1-x-yGexCy layer which completely filters out excess interstitials introduced by oxidation or ion implant damage. We also quantify the oxidation-enhanced diffusion (OED) and transient-enhanced diffusion (TED) dependence on substitutional carbon level, and further report both the observation of carbon TED and OED, and its dependence on carbon levels.

On the behaviour of dissolved fission gases prior to transient testing of fuel pins

International Nuclear Information System (INIS)

Wood, M.H.; Matthews, J.R.

1978-10-01

The TREAT and CABRI series of reactor safety experiments on irradiated fuel require the transfer of fuel pins from the reactor in which the fuel has achieved some burn-up to the test facility. Subsequently, the fuel is restored to power in the test facility for some time before transient heating is initiated. Such pre-test manoeuvres, where the fuel is subjected to changes in the fission rate and temperature, may have important consequences for the fission gas behaviour during the transient experiment. The results of rate theory calculations are used to assess these effects. (author)

Water soluble nano-scale transient material germanium oxide for zero toxic waste based environmentally benign nano-manufacturing

KAUST Repository

Almuslem, A. S.

2017-02-14

In the recent past, with the advent of transient electronics for mostly implantable and secured electronic applications, the whole field effect transistor structure has been dissolved in a variety of chemicals. Here, we show simple water soluble nano-scale (sub-10 nm) germanium oxide (GeO) as the dissolvable component to remove the functional structures of metal oxide semiconductor devices and then reuse the expensive germanium substrate again for functional device fabrication. This way, in addition to transiency, we also show an environmentally friendly manufacturing process for a complementary metal oxide semiconductor (CMOS) technology. Every year, trillions of complementary metal oxide semiconductor (CMOS) electronics are manufactured and billions are disposed, which extend the harmful impact to our environment. Therefore, this is a key study to show a pragmatic approach for water soluble high performance electronics for environmentally friendly manufacturing and bioresorbable electronic applications.

Chronic Iron Limitation Confers Transient Resistance to Oxidative Stress in Marine Diatoms1

Science.gov (United States)

Graff van Creveld, Shiri; Rosenwasser, Shilo; Vardi, Assaf

2016-01-01

Diatoms are single-celled, photosynthetic, bloom-forming algae that are responsible for at least 20% of global primary production. Nevertheless, more than 30% of the oceans are considered “ocean deserts” due to iron limitation. We used the diatom Phaeodactylum tricornutum as a model system to explore diatom’s response to iron limitation and its interplay with susceptibility to oxidative stress. By analyzing physiological parameters and proteome profiling, we defined two distinct phases: short-term (5 d, phase II) iron limitation. While at phase I no significant changes in physiological parameters were observed, molecular markers for iron starvation, such as Iron Starvation Induced Protein and flavodoxin, were highly up-regulated. At phase II, down-regulation of numerous iron-containing proteins was detected in parallel to reduction in growth rate, chlorophyll content, photosynthetic activity, respiration rate, and antioxidant capacity. Intriguingly, while application of oxidative stress to phase I and II iron-limited cells similarly oxidized the reduced glutathione (GSH) pool, phase II iron limitation exhibited transient resistance to oxidative stress, despite the down regulation of many antioxidant proteins. By comparing proteomic profiles of P. tricornutum under iron limitation and metatranscriptomic data of an iron enrichment experiment conducted in the Pacific Ocean, we propose that iron-limited cells in the natural environment resemble the phase II metabolic state. These results provide insights into the trade-off between optimal growth rate and susceptibility to oxidative stress in the response of diatoms to iron quota in the marine environment. PMID:27503604

PWR station blackout transient simulation in the INER integral system test facility

International Nuclear Information System (INIS)

Liu, T.J.; Lee, C.H.; Hong, W.T.; Chang, Y.H.

2004-01-01

Station blackout transient (or TMLB' scenario) in a pressurized water reactor (PWR) was simulated using the INER Integral System Test Facility (IIST) which is a 1/400 volumetrically-scaled reduce-height and reduce-pressure (RHRP) simulator of a Westinghouse three-loop PWR. Long-term thermal-hydraulic responses including the secondary boil-off and the subsequent primary saturation, pressurization and core uncovery were simulated based on the assumptions of no offsite and onsite power, feedwater and operator actions. The results indicate that two-phase discharge is the major depletion mode since it covers 81.3% of the total amount of the coolant inventory loss. The primary coolant inventory has experienced significant re-distribution during a station blackout transient. The decided parameter to avoid the core overheating is not the total amount of the coolant inventory remained in the primary core cooling system but only the part of coolant left in the pressure vessel. The sequence of significant events during transient for the IIST were also compared with those of the ROSA-IV large-scale test facility (LSTF), which is a 1/48 volumetrically-scaled full-height and full-pressure (FHFP) simulator of a PWR. The comparison indicates that the sequence and timing of these events during TMLB' transient studied in the RHRP IIST facility are generally consistent with those of the FHFP LSTF. (author)

Preliminary Analysis of the Transient Reactor Test Facility (TREAT) with PROTEUS

Energy Technology Data Exchange (ETDEWEB)

Connaway, H. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lee, C. H. [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-11-30

The neutron transport code PROTEUS has been used to perform preliminary simulations of the Transient Reactor Test Facility (TREAT). TREAT is an experimental reactor designed for the testing of nuclear fuels and other materials under transient conditions. It operated from 1959 to 1994, when it was placed on non-operational standby. The restart of TREAT to support the U.S. Department of Energy’s resumption of transient testing is currently underway. Both single assembly and assembly-homogenized full core models have been evaluated. Simulations were performed using a historic set of WIMS-ANL-generated cross-sections as well as a new set of Serpent-generated cross-sections. To support this work, further analyses were also performed using additional codes in order to investigate particular aspects of TREAT modeling. DIF3D and the Monte-Carlo codes MCNP and Serpent were utilized in these studies. MCNP and Serpent were used to evaluate the effect of geometry homogenization on the simulation results and to support code-to-code comparisons. New meshes for the PROTEUS simulations were created using the CUBIT toolkit, with additional meshes generated via conversion of selected DIF3D models to support code-to-code verifications. All current analyses have focused on code-to-code verifications, with additional verification and validation studies planned. The analysis of TREAT with PROTEUS-SN is an ongoing project. This report documents the studies that have been performed thus far, and highlights key challenges to address in future work.

Reactor transients tests for SNR fuel elements in HFR reactor

International Nuclear Information System (INIS)

Plitz, H.

1989-01-01

In HFR reactor, fuel pins of LMFBR reactors are putted in irradiation specimen capsules cooled with sodium for reactor transients tests. These irradiation capsules are instrumented and the experiences realized until this day give results on: - Fuel pins subjected at a continual variation of power - melting fuel - axial differential elongation of fuel pins

Impacts Analyses Supporting the National Environmental Policy Act Environmental Assessment for the Resumption of Transient Testing Program

Energy Technology Data Exchange (ETDEWEB)

Annette L. Schafer; Lloyd C. Brown; David C. Carathers; Boyd D. Christensen; James J. Dahl; Mark L. Miller; Cathy Ottinger Farnum; Steven Peterson; A. Jeffrey Sondrup; Peter V. Subaiya; Daniel M. Wachs; Ruth F. Weiner

2013-11-01

Environmental and health impacts are presented for activities associated with transient testing of nuclear fuel and material using two candidate test reactors. Transient testing involves irradiation of nuclear fuel or materials for short time-periods under high neutron flux rates. The transient testing process includes transportation of nuclear fuel or materials inside a robust shipping cask to a hot cell, removal from the shipping cask, pre-irradiation examination of the nuclear materials, assembly of an experiment assembly, transportation of the experiment assembly to the test reactor, irradiation in the test reactor, transport back to the hot cell, and post-irradiation examination of the nuclear fuel or material. The potential for environmental or health consequences during the transportation, examination, and irradiation actions are assessed for normal operations, off-normal (accident) scenarios, and transportation. Impacts to the environment (air, soil, and groundwater), are assessed during each phase of the transient testing process. This report documents the evaluation of potential consequences to the general public. This document supports the Environmental Assessment (EA) required by the U.S. National Environmental Policy Act (NEPA) (42 USC Subsection 4321 et seq.).

Influence of startup oxidizing transients of IGA/SCC in PWR steam generators

International Nuclear Information System (INIS)

Gorman, J.A.; McIlree, A.R.; Gaudreau, T.; Bjornkvist, L.; Andersson, P.-O.

1998-01-01

There is a considerable amount of evidence oxidizing conditions during and following startups are an important factor in the intergranular corrosion/stress corrosion cracking (IGA/SCC) of mill annealed alloy 600 steam generator tubes. This evidence includes plant data that indicate that the growth of IGA/SCC correlates better in some cases with numbers of startups than with time at power, laboratory tests in several plausible crevice environments that show that small amounts of copper oxides accelerate the rate of IGA/SCC, laboratory tests that show that elevating the electrochemical potential (ECP) increases the rates of IGA/SCC in many chemical environments, and laboratory tests that show that copper oxides, hematite, and other oxidized corrosion products can raise the ECP of several solution chemistries into aggressive ranges. Some preliminary data also exist that show that some amounts of oxidized species are produced during typical layup and startup conditions, but data for the subsequent reduction of these oxides are largely lacking. The purpose of this paper is to review the available evidence, to arrive at conclusions regarding the probable importance of oxidizing conditions during startup on occurrence of IGA/SCC, and to identify needed research to better quantify the situation. (author)

Transient absorption microscopy studies of energy relaxation in graphene oxide thin film.

Science.gov (United States)

Murphy, Sean; Huang, Libai

2013-04-10

Spatial mapping of energy relaxation in graphene oxide (GO) thin films has been imaged using transient absorption microscopy (TAM). Correlated AFM images allow us to accurately determine the thickness of the GO films. In contrast to previous studies, correlated TAM-AFM allows determination of the effect of interactions of GO with the substrate and between stacked GO layers on the relaxation dynamics. Our results show that energy relaxation in GO flakes has little dependence on the substrate, number of stacked layers, and excitation intensity. This is in direct contrast to pristine graphene, where these factors have great consequences in energy relaxation. This suggests intrinsic factors rather than extrinsic ones dominate the excited state dynamics of GO films.

Transient absorption microscopy studies of energy relaxation in graphene oxide thin film

International Nuclear Information System (INIS)

Murphy, Sean; Huang, Libai

2013-01-01

Spatial mapping of energy relaxation in graphene oxide (GO) thin films has been imaged using transient absorption microscopy (TAM). Correlated AFM images allow us to accurately determine the thickness of the GO films. In contrast to previous studies, correlated TAM–AFM allows determination of the effect of interactions of GO with the substrate and between stacked GO layers on the relaxation dynamics. Our results show that energy relaxation in GO flakes has little dependence on the substrate, number of stacked layers, and excitation intensity. This is in direct contrast to pristine graphene, where these factors have great consequences in energy relaxation. This suggests intrinsic factors rather than extrinsic ones dominate the excited state dynamics of GO films. (paper)

Behavior of metallic fuel in treat transient overpower tests

International Nuclear Information System (INIS)

Bauer, T.H.; Wright, A.E.; Robinson, W.R.; Klickman, A.E.

1988-01-01

Results and analyses are reported for TREAT in-pile transient overpower tests of margin to cladding failure and pre-failure axial expansion of metallic fuel. In all cases the power rise was exponential on an 8 s period until either incipient or actual cladding failure was achieved. Test fuel included EBR-II driver fuel and ternary alloy, the reference fuel of the Intergral Fast Reactor concept. Test pin burnup spanned the widest range available. The nature of the observed cladding failure and resultant fuel dispersals is described. Simple models are presented which describe observed cladding failures and pre-failure axial expansions yet are general enough to apply to all metal fuel types

Analysis of transient fission gas behaviour in oxide fuel using BISON and TRANSURANUS

Energy Technology Data Exchange (ETDEWEB)

Barani, T.; Bruschi, E.; Pizzocri, D. [Politecnico di Milano, Department of Energy, Nuclear Engineering Division, Via La Masa 34, I-20156 Milano (Italy); Pastore, G. [Fuel Modeling and Simulation Department, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Van Uffelen, P. [European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, P.O. Box 2340, 76125 Karlsruhe (Germany); Williamson, R.L. [Fuel Modeling and Simulation Department, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Luzzi, L., E-mail: Lelio.Luzzi@polimi.it [Politecnico di Milano, Department of Energy, Nuclear Engineering Division, Via La Masa 34, I-20156 Milano (Italy)

2017-04-01

The modelling of fission gas behaviour is a crucial aspect of nuclear fuel performance analysis in view of the related effects on the thermo-mechanical performance of the fuel rod, which can be particularly significant during transients. In particular, experimental observations indicate that substantial fission gas release (FGR) can occur on a small time scale during transients (burst release). To accurately reproduce the rapid kinetics of the burst release process in fuel performance calculations, a model that accounts for non-diffusional mechanisms such as fuel micro-cracking is needed. In this work, we present and assess a model for transient fission gas behaviour in oxide fuel, which is applied as an extension of conventional diffusion-based models to introduce the burst release effect. The concept and governing equations of the model are presented, and the sensitivity of results to the newly introduced parameters is evaluated through an analytic sensitivity analysis. The model is assessed for application to integral fuel rod analysis by implementation in two structurally different fuel performance codes: BISON (multi-dimensional finite element code) and TRANSURANUS (1.5D code). Model assessment is based on the analysis of 19 light water reactor fuel rod irradiation experiments from the OECD/NEA IFPE (International Fuel Performance Experiments) database, all of which are simulated with both codes. The results point out an improvement in both the quantitative predictions of integral fuel rod FGR and the qualitative representation of the FGR kinetics with the transient model relative to the canonical, purely diffusion-based models of the codes. The overall quantitative improvement of the integral FGR predictions in the two codes is comparable. Moreover, calculated radial profiles of xenon concentration after irradiation are investigated and compared to experimental data, illustrating the underlying representation of the physical mechanisms of burst release

Sodium boiling and mixed oxide fuel thermal behavior in FBR undercooling transients; W-1 SLSF experiment results

International Nuclear Information System (INIS)

Henderson, J.M.; Wood, S.A.; Knight, D.D.

1981-01-01

The W-1 Sodium Loop Safety Facility (SLSF) Experiment was conducted to study fuel pin heat release characteristics during a series of LMFBR Loss-of-Piping Integrity (LOPI) transients and to investigate a regime of coolant boiling during a second series of transients at low, medium and high bundle power levels. The LOPI transients produced no coolant boiling and showed only small changes in coolant temperatures as the test fuel microstructure changed from a fresh, unrestructured to a low burnup, restructured condition. During the last of seven boiling transients, intense coolant boiling produced inlet flow reversal, cladding dryout and moderate cladding melting

Modeling transient streaming potentials in falling-head permeameter tests.

Science.gov (United States)

Malama, Bwalya; Revil, André

2014-01-01

We present transient streaming potential data collected during falling-head permeameter tests performed on samples of two sands with different physical and chemical properties. The objective of the work is to estimate hydraulic conductivity (K) and the electrokinetic coupling coefficient (Cl ) of the sand samples. A semi-empirical model based on the falling-head permeameter flow model and electrokinetic coupling is used to analyze the streaming potential data and to estimate K and Cl . The values of K estimated from head data are used to validate the streaming potential method. Estimates of K from streaming potential data closely match those obtained from the associated head data, with less than 10% deviation. The electrokinetic coupling coefficient was estimated from streaming potential vs. (1) time and (2) head data for both sands. The results indicate that, within limits of experimental error, the values of Cl estimated by the two methods are essentially the same. The results of this work demonstrate that a temporal record of the streaming potential response in falling-head permeameter tests can be used to estimate both K and Cl . They further indicate the potential for using transient streaming potential data as a proxy for hydraulic head in hydrogeology applications. © 2013, National Ground Water Association.

Evaluation of the Non-Transient Hydrologic Source Term from the CAMBRIC Underground Nuclear Test in Frenchman Flat, Nevada Test Site

International Nuclear Information System (INIS)

Tompson, A B; Maxwell, R M; Carle, S F; Zavarin, M; Pawloski, G A.; Shumaker, D E

2005-01-01

Hydrologic Source Term (HST) calculations completed in 1998 at the CAMBRIC underground nuclear test site were LLNL's first attempt to simulate a hydrologic source term at the NTS by linking groundwater flow and transport modeling with geochemical modeling (Tompson et al., 1999). Significant effort was applied to develop a framework that modeled in detail the flow regime and captured all appropriate chemical processes that occurred over time. However, portions of the calculations were simplified because of data limitations and a perceived need for generalization of the results. For example: (1) Transient effects arising from a 16 years of pumping at the site for a radionuclide migration study were not incorporated. (2) Radionuclide fluxes across the water table, as derived from infiltration from a ditch to which pumping effluent was discharged, were not addressed. (3) Hydrothermal effects arising from residual heat of the test were not considered. (4) Background data on the ambient groundwater flow direction were uncertain and not represented. (5) Unclassified information on the Radiologic Source Term (RST) inventory, as tabulated recently by Bowen et al. (2001), was unavailable; instead, only a limited set of derived data were available (see Tompson et al., 1999). (6) Only a small number of radionuclides and geochemical reactions were incorporated in the work. (7) Data and interpretation of the RNM-2S multiple well aquifer test (MWAT) were not available. As a result, the current Transient CAMBRIC Hydrologic Source Term project was initiated as part of a broader Phase 2 Frenchman Flat CAU flow and transport modeling effort. The source term will be calculated under two scenarios: (1) A more specific representation of the transient flow and radionuclide release behavior at the site, reflecting the influence of the background hydraulic gradient, residual test heat, pumping experiment, and ditch recharge, and taking into account improved data sources and modeling

Barometric pressure transient testing applications at the Nevada Test Site: formation permeability analysis. Final report

International Nuclear Information System (INIS)

Hanson, J.M.

1984-12-01

The report evaluates previous investigations of the gas permeability of the rock surrounding emplacement holes at the Nevada Test Site. The discussion sets the framework from which the present uncertainty in gas permeability can be overcome. The usefulness of the barometric pressure testing method has been established. Flow models were used to evaluate barometric pressure transients taken at NTS holes U2fe, U19ac and U20ai. 31 refs., 103 figs., 18 tabs

Transient and steady-state tests of the space power research engine with resistive and motor loads

Science.gov (United States)

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Transient and Steady-state Tests of the Space Power Research Engine with Resistive and Motor Loads

Science.gov (United States)

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Testing the ontogenetic base for the transient model of inflorescence development.

Science.gov (United States)

Bull-Hereñu, Kester; Claßen-Bockhoff, Regine

2013-11-01

Current research in plant science has concentrated on revealing ontogenetic processes of key attributes in plant evolution. One recently discussed model is the 'transient model' successful in explaining some types of inflorescence architectures based on two main principles: the decline of the so called 'vegetativeness' (veg) factor and the transient nature of apical meristems in developing inflorescences. This study examines whether both principles find a concrete ontogenetic correlate in inflorescence development. To test the ontogenetic base of veg decline and the transient character of apical meristems the ontogeny of meristematic size in developing inflorescences was investigated under scanning electron microscopy. Early and late inflorescence meristems were measured and compared during inflorescence development in 13 eudicot species from 11 families. The initial size of the inflorescence meristem in closed inflorescences correlates with the number of nodes in the mature inflorescence. Conjunct compound inflorescences (panicles) show a constant decrease of meristematic size from early to late inflorescence meristems, while disjunct compound inflorescences present an enlargement by merging from early inflorescence meristems to late inflorescence meristems, implying a qualitative change of the apical meristems during ontogeny. Partial confirmation was found for the transient model for inflorescence architecture in the ontogeny: the initial size of the apical meristem in closed inflorescences is consistent with the postulated veg decline mechanism regulating the size of the inflorescence. However, the observed biphasic kinetics of the development of the apical meristem in compound racemes offers the primary explanation for their disjunct morphology, contrary to the putative exclusive transient mechanism in lateral axes as expected by the model.

Comparison of transient PCRV model test results with analysis

International Nuclear Information System (INIS)

Marchertas, A.H.; Belytschko, T.B.

1979-01-01

Comparisons are made of transient data derived from simple models of a reactor containment vessel with analytical solutions. This effort is a part of the ongoing process of development and testing of the DYNAPCON computer code. The test results used in these comparisons were obtained from scaled models of the British sodium cooled fast breeder program. The test structure is a scaled model of a cylindrically shaped reactor containment vessel made of concrete. This concrete vessel is prestressed axially by holddown bolts spanning the top and bottom slabs along the cylindrical walls, and is also prestressed circumferentially by a number of cables wrapped around the vessel. For test purposes this containment vessel is partially filled with water, which comes in direct contact with the vessel walls. The explosive charge is immersed in the pool of water and is centrally suspended from the top of the vessel. The load history was obtained from an ICECO analysis, using the equations of state for the source and the water. A detailed check of this solution was made to assure that the derived loading did provide the correct input. The DYNAPCON code was then used for the analysis of the prestressed concrete containment model. This analysis required the simulation of prestressing and the response of the model to the applied transient load. The calculations correctly predict the magnitudes of displacements of the PCRV model. In addition, the displacement time histories obtained from the calculations reproduce the general features of the experimental records: the period elongation and amplitude increase as compared to an elastic solution, and also the absence of permanent displacement. However, the period still underestimates the experiment, while the amplitude is generally somewhat large

Deep-level transient spectroscopy on an amorphous InGaZnO4 Schottky diode

NARCIS (Netherlands)

Chasin, A.; Simoen, E.; Bhoolokam, A.; Nag, M.; Genoe, J.; Gielen, G.; Heremans, P.

2014-01-01

The first direct measurement is reported of the bulk density of deep states in amorphous IGZO (indium-gallium-zinc oxide) semiconductor by means of deep-level transient spectroscopy (DLTS). The device under test is a Schottky diode of amorphous IGZO semiconductor on a palladium (Pd) Schottky-barrier

Oxidation of boron carbide at high temperatures

International Nuclear Information System (INIS)

Steinbrueck, Martin

2005-01-01

The oxidation kinetics of various types of boron carbides (pellets, powder) were investigated in the temperature range between 1073 and 1873 K. Oxidation rates were measured in transient and isothermal tests by means of mass spectrometric gas analysis. Oxidation of boron carbide is controlled by the formation of superficial liquid boron oxide and its loss due to the reaction with surplus steam to volatile boric acids and/or direct evaporation at temperatures above 1770 K. The overall reaction kinetics is paralinear. Linear oxidation kinetics established soon after the initiation of oxidation under the test conditions described in this report. Oxidation is strongly influenced by the thermohydraulic boundary conditions and in particular by the steam partial pressure and flow rate. On the other hand, the microstructure of the B 4 C samples has a limited influence on oxidation. Very low amounts of methane were produced in these tests

Simulation of loss of feedwater transient of MASLWR test facility by MARS-KS code

Energy Technology Data Exchange (ETDEWEB)

Park, Juyeop [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2013-05-15

MASLWR test facility is a mock-up of a passive integral type reactor equipped with helical coil steam generator. Since SMART reactor which is being current developed domestically also adopts helical coil steam generator, KINS has joined this ICSP to evaluate performance of domestic regulatory audit thermal-hydraulic code (MARS-KS code) in various respects including wall-to-fluid heat transfer model modification implemented in the code by independent international experiment database. In the ICSP, two types of transient experiments have been focused and they are loss of feedwater transient with subsequent ADS operation and long term cooling (SP-2) and normal operating conditions at different power levels (SP-3). In the present study, KINS simulation results by the MARS-KS code (KS-002 version) for the SP-2 experiment are presented in detail and conclusions on MARS-KS code performance drawn through this simulation is described. Performance of the MARS-KS code is evaluated through the simulation of the loss of feedwater transient of the MASLWR test facility. Steady state run shows helical coil specific heat transfer models implemented in the code is reasonable. However, through the transient run, it is also found that three-dimensional effect within the HPC and axial conduction effect through the HTP are not well reproduced by the code.

Mitochondrial Alterations and Oxidative Stress in an Acute Transient Mouse Model of Muscle Degeneration

Science.gov (United States)

Ramadasan-Nair, Renjini; Gayathri, Narayanappa; Mishra, Sudha; Sunitha, Balaraju; Mythri, Rajeswara Babu; Nalini, Atchayaram; Subbannayya, Yashwanth; Harsha, Hindalahalli Chandregowda; Kolthur-Seetharam, Ullas; Bharath, Muchukunte Mukunda Srinivas

2014-01-01

Muscular dystrophies (MDs) and inflammatory myopathies (IMs) are debilitating skeletal muscle disorders characterized by common pathological events including myodegeneration and inflammation. However, an experimental model representing both muscle pathologies and displaying most of the distinctive markers has not been characterized. We investigated the cardiotoxin (CTX)-mediated transient acute mouse model of muscle degeneration and compared the cardinal features with human MDs and IMs. The CTX model displayed degeneration, apoptosis, inflammation, loss of sarcolemmal complexes, sarcolemmal disruption, and ultrastructural changes characteristic of human MDs and IMs. Cell death caused by CTX involved calcium influx and mitochondrial damage both in murine C2C12 muscle cells and in mice. Mitochondrial proteomic analysis at the initial phase of degeneration in the model detected lowered expression of 80 mitochondrial proteins including subunits of respiratory complexes, ATP machinery, fatty acid metabolism, and Krebs cycle, which further decreased in expression during the peak degenerative phase. The mass spectrometry (MS) data were supported by enzyme assays, Western blot, and histochemistry. The CTX model also displayed markers of oxidative stress and a lowered glutathione reduced/oxidized ratio (GSH/GSSG) similar to MDs, human myopathies, and neurogenic atrophies. MS analysis identified 6 unique oxidized proteins from Duchenne muscular dystrophy samples (n = 6) (versus controls; n = 6), including two mitochondrial proteins. Interestingly, these mitochondrial proteins were down-regulated in the CTX model thereby linking oxidative stress and mitochondrial dysfunction. We conclude that mitochondrial alterations and oxidative damage significantly contribute to CTX-mediated muscle pathology with implications for human muscle diseases. PMID:24220031

Comparison of transient PCRV model test results with analysis

International Nuclear Information System (INIS)

Marchertas, A.H.; Belytschko, T.B.

1979-01-01

Comparisons are made of transient data derived from simple models of a reactor containment vessel with analytical solutions. This effort is a part of the ongoing process of development and testing of the DYNAPCON computer code. The test results used in these comparisons were obtained from scaled models of the British sodium cooled fast breeder program. The test structure is a scaled model of a cylindrically shaped reactor containment vessel made of concrete. This concrete vessel is prestressed axially by holddown bolts spanning the top and bottom slabs along the cylindrical walls, and is also prestressed circumferentially by a number of cables wrapped around the vessel. For test purposes this containment vessel is partially filled with water, which comes in direct contact with the vessel walls. The explosive charge is immersed in the pool of water and is centrally suspended from the top of the vessel. The tests are very similar to the series of tests made for the COVA experimental program, but the vessel here is the prestressed concrete container. (orig.)

ANO-2 turbine trip transient test analysis using MMS

International Nuclear Information System (INIS)

Jain, P.K.; Divakaruni, S.M.

1984-01-01

The data from the turbine trip transient tests conducted at the Arkansas Nuclear One-Unit 2 was used as one of the benchmark cases for validating the Modular Modeling System (MMS) Code, developed by the Electric Power Research Institute (EPRI). The data was used first to validate the modules in stand-alone simulation tests and then in a Nuclear Steam Supply system integral tests. This paper presents the results from the MMS simulation effort and compares the code generated results with the plant data as well as RETRAN results. In general, MMS simulation results compare very well with the plant data. The code calculations for the hot and cold leg temperatures, primary system pressure and the pressurizer level are very good compared to RETRAN; however, MMS results for steam generator level compare reasonably well only with RETRAN calculations

Impacts Analyses Supporting the National Environmental Policy Act Environmental Assessment for the Resumption of Transient Testing Program

Energy Technology Data Exchange (ETDEWEB)

Schafer, Annette L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Brown, LLoyd C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Carathers, David C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Christensen, Boyd D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dahl, James J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, Mark L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Farnum, Cathy Ottinger [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peterson, Steven [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sondrup, A. Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States); Subaiya, Peter V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wachs, Daniel M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Weiner, Ruth F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2014-02-01

This document contains the analysis details and summary of analyses conducted to evaluate the environmental impacts for the Resumption of Transient Fuel and Materials Testing Program. It provides an assessment of the impacts for the two action alternatives being evaluated in the environmental assessment. These alternatives are (1) resumption of transient testing using the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) and (2) conducting transient testing using the Annular Core Research Reactor (ACRR) at Sandia National Laboratory in New Mexico (SNL/NM). Analyses are provided for radiologic emissions, other air emissions, soil contamination, and groundwater contamination that could occur (1) during normal operations, (2) as a result of accidents in one of the facilities, and (3) during transport. It does not include an assessment of the biotic, cultural resources, waste generation, or other impacts that could result from the resumption of transient testing. Analyses were conducted by technical professionals at INL and SNL/NM as noted throughout this report. The analyses are based on bounding radionuclide inventories, with the same inventories used for test materials by both alternatives and different inventories for the TREAT Reactor and ACRR. An upper value on the number of tests was assumed, with a test frequency determined by the realistic turn-around times required between experiments. The estimates provided for impacts during normal operations are based on historical emission rates and projected usage rates; therefore, they are bounding. Estimated doses for members of the public, collocated workers, and facility workers that could be incurred as a result of an accident are very conservative. They do not credit safety systems or administrative procedures (such as evacuation plans or use of personal protective equipment) that could be used to limit worker doses. Doses estimated for transportation are conservative and are based on

System Re-set: High LET Radiation or Transient Musculoskeletal Disuse Cause Lasting Changes in Oxidative Defense Pathways Within Bone

Science.gov (United States)

Kumar, Akhilesh; Chatterjee, A.; Alwood, Joshua S.; Dvorochkin, Natalya; Almeida, Eduardo A. C.

2011-01-01

Six months post-IR, there were no notable changes in skeletal expression of 84 principal genes in the p53 signaling pathway due to low dose IR (0.5Gy), HU, or both. In contrast, numerous genes relevant to oxidative stress were regulated by the treatments, typically in a direction indicative of increased oxidative stress and impaired defense. IR and HU independently reduced (between 0.46 to 0.88 fold) expression levels of Noxa1, Gpx3, Prdx2, Prdx3, and Zmynd17. Surprisingly, transient HU alone (sham-irradiated) decreased expression of several redox-related genes (Gpx1,Gstk1, Prdx1, Txnrd2), which were not affected significantly by IR alone. Irradiation increased (1.13 fold) expression of a gene responsible for production of superoxides by neutrophils (NCF2). Of interest, only combined treatment with HU and IR led to increased expression levels of Ercc2, (1.19 fold), a DNA excision repair enzyme. Differences in gene expression levels may reflect a change in gene expression on a per cell basis, a shift in the repertoire of specific cell types within the tissue, or both. Serum nitrite/nitrate levels were elevated to comparable levels (1.6-fold) due to IR, HU or both, indicative of elevated systemic nitrosyl stress. CONCLUSIONS The magnitude of changes in skeletal expression of oxidative stress-related genes six months after irradiation and/or transient unloading tended to be relatively modest (0.46-1.15 fold), whereas the p53 pathway was not affected. The finding that many different oxidative stress-related genes differed from controls at this late time point implicates a generalized impairment of oxidative defense within skeletal tissue, which coincides with both profound radiation damage to osteoprogenitors/stem cells in bone marrow and impaired remodeling of mineralized tissue.

MODELLING OF NON-ROAD TRANSIENT CYCLE

Directory of Open Access Journals (Sweden)

Martin Kotus

2013-12-01

Full Text Available The paper describes the modeling of NRTC (Non-Road Transient Cycle test procedure based on previously measured characteristics of fuel consumption, carbon monoxide (CO, carbon dioxide (CO2, hydrocarbons (HC, nitrogen oxides (NOx and particulates (PM production. It makes possible to compare the current technical condition of an internal combustion engine of an agricultural tractor with its previous state or other tractor’s engine. Based on measured characteristics, it is also possible to model any other cycle without further measurements (NRSC test procedure, cycle for specific conditions – mountain tractor, etc.. The result may thus contribute to improving the environment by reducing the production of harmful substances emitted into the air and save money due to reduced fuel consumption.

Near-surface effects of transient oxidation and reduction on Nb-doped SrTiO3 epitaxial thin films

Science.gov (United States)

Chang, C. F.; Chen, Q. Y.; Wadekar, P. V.; Lozano, O.; Wong, M. S.; Hsieh, W. C.; Lin, W. Y.; Ko, H. H.; Lin, Q. J.; Huang, H. C.; Ho, N. J.; Tu, L. W.; Liao, H. H.; Chinta, P. V.; Chu, W. K.; Seo, H. W.

2014-03-01

We studied the effects of transient oxidation and reduction of Nb-doped epitaxial thin films through variations of PAr and PO2. The samples were prepared by co-sputtering of Nb and SrTiO3 on LaAlO3 substrates. The Nb-content were varied from 0-33.7%, as determined by PIXE. Contact resistance, sheet resistance, and optical properties are used to discriminate the effects.

Parametric investigation on transient boiling heat transfer of metal rod cooled rapidly in water pool

Energy Technology Data Exchange (ETDEWEB)

Lee, Chi Young [Department of Fire Protection Engineering, Pukyong National University, 45, Yongso-ro, Nam-gu, Busan 48513 (Korea, Republic of); Kim, Sunwoo, E-mail: swkim@alaska.edu [Mechanical Engineering Department, University of Alaska Fairbanks, P. O. Box 755905, Fairbanks, AK 99775-5905 (United States)

2017-03-15

Highlights: • Effects of liquid subcooling, surface coating, material property, and surface oxidation are examined. • Liquid subcooling affects remarkably the quenching phenomena. • Cr-coated surfaces for ATF might extend the quenching duration. • Solids with low heat capacity shorten the quenching duration. • Surface oxidation can affect strongly the film boiling heat transfer and MFB point. - Abstract: In this work, the effects of liquid subcooling, surface coating, material property, and surface oxidation on transient pool boiling heat transfer were investigated experimentally using the vertical metal rod and quenching method. The change in rod temperature was measured with time during quenching, and the visualization of boiling around the test specimen was performed using the high-speed video camera. As the test materials, the zircaloy (Zry), stainless steel (SS), niobium (Nb), and copper (Cu) were tested. In addition, the chromium-coated niobium (Cr-Nb) and chromium-coated stainless steel (Cr-SS) were prepared for accident tolerant fuel (ATF) application. Low liquid subcooling and Cr-coating shifted the quenching curve to the right, which indicates a prolongation of quenching duration. On the other hand, the material with small heat capacity and surface oxidation caused the quenching curve to move to the left. To examine the influence of the material property and surface oxidation on the film boiling heat transfer performance and minimum film boiling (MFB) point in more detail, the wall temperature and heat flux were calculated from the present transient temperature profile using the inverse heat transfer analysis, and then the curves of wall temperature and heat flux in the film boiling regime were obtained. In the present experimental conditions, the effect of material property on the film boiling heat transfer performance and MFB point seemed to be minor. On the other hand, based on the experimental results of the Cu test specimen, the surface

Work plan: transient release from LMFBR fuel

International Nuclear Information System (INIS)

Kress, T.S.; Parker, G.W.; Fontana, M.H.

1975-09-01

The proposed LMFBR Transient Release Program at ORNL is designed to investigate, by means of ex-reactor experiments and analytical modeling, the release and transport of fuel, fission products, and transuranic elements from fast reactor cores in the event of certain hypothetical accidents. It is desired to experimentally produce energy depositions that are characteristic of severe hypothetical reactor transients by the application of direct electrical current to mixed-oxide fuels under sodium. The experimental program includes tests with and without sodium, investigations of alternative methods of generating fuel and sodium aerosols, the use of UO 2 as a fuel simulant, additions of tracers as fission product simulants, effects of radiation, and under-water and under-sodium efforts to study the behavior of the vapor bubble itself. Analytical modeling will accompany all phases of the program, and the data will be correlated with models developed. 21 references. (auth)

21 CFR 862.3080 - Breath nitric oxide test system.

Science.gov (United States)

2010-04-01

... Systems § 862.3080 Breath nitric oxide test system. (a) Identification. A breath nitric oxide test system... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath nitric oxide test system. 862.3080 Section... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to...

Iodine oxides in large-scale THAI tests

International Nuclear Information System (INIS)

Funke, F.; Langrock, G.; Kanzleiter, T.; Poss, G.; Fischer, K.; Kühnel, A.; Weber, G.; Allelein, H.-J.

2012-01-01

Highlights: ► Iodine oxide particles were produced from gaseous iodine and ozone. ► Ozone replaced the effect of ionizing radiation in the large-scale THAI facility. ► The mean diameter of the iodine oxide particles was about 0.35 μm. ► Particle formation was faster than the chemical reaction between iodine and ozone. ► Deposition of iodine oxide particles was slow in the absence of other aerosols. - Abstract: The conversion of gaseous molecular iodine into iodine oxide aerosols has significant relevance in the understanding of the fission product iodine volatility in a LWR containment during severe accidents. In containment, the high radiation field caused by fission products released from the reactor core induces radiolytic oxidation into iodine oxides. To study the characteristics and the behaviour of iodine oxides in large scale, two THAI tests Iod-13 and Iod-14 were performed, simulating radiolytic oxidation of molecular iodine by reaction of iodine with ozone, with ozone injected from an ozone generator. The observed iodine oxides form submicron particles with mean volume-related diameters of about 0.35 μm and show low deposition rates in the THAI tests performed in the absence of other nuclear aerosols. Formation of iodine aerosols from gaseous precursors iodine and ozone is fast as compared to their chemical interaction. The current approach in empirical iodine containment behaviour models in severe accidents, including the radiolytic production of I 2 -oxidizing agents followed by the I 2 oxidation itself, is confirmed by these THAI tests.

Repeated exposure of adult rats to transient oxidative stress induces various long-lasting alterations in cognitive and behavioral functions.

Directory of Open Access Journals (Sweden)

Yoshio Iguchi

Full Text Available Exposure of neonates to oxidative stress may increase the risk of psychiatric disorders such as schizophrenia in adulthood. However, the effects of moderate oxidative stress on the adult brain are not completely understood. To address this issue, we systemically administrated 2-cyclohexen-1-one (CHX to adult rats to transiently reduce glutathione levels. Repeated administration of CHX did not affect the acquisition or motivation of an appetitive instrumental behavior (lever pressing rewarded by a food outcome under a progressive ratio schedule. In addition, response discrimination and reversal learning were not affected. However, acute CHX administration blunted the sensitivity of the instrumental performance to outcome devaluation, and this effect was prolonged in rats with a history of repeated CHX exposure, representing pro-depression-like phenotypes. On the other hand, repeated CHX administration reduced immobility in forced swimming tests and blunted acute cocaine-induced behaviors, implicating antidepressant-like effects. Multivariate analyses segregated a characteristic group of behavioral variables influenced by repeated CHX administration. Taken together, these findings suggest that repeated administration of CHX to adult rats did not cause a specific mental disorder, but it induced long-term alterations in behavioral and cognitive functions, possibly related to specific neural correlates.

COMETHE III-M for transient fuel rod behaviour prediction

International Nuclear Information System (INIS)

Billaux, M.; Vliet, J. van

1983-01-01

The COMETHE III-M version is being developed in order to provide fuel rod behaviour prediction capability both in steady-state and in transient situations. It also allows to estimate the fuel rod enthalpy evolution versus time or burnup which may be important in core-related safety studies. This paper describes the transient heat transfer models, including transient heat conduction inside the fuel rod, and a subchannel model providing transient flow as well as enthalpy calculation capability. Transient fission gas release is also modelled on basis of the change rate of oxide temperature. The models are illustrated by a few calculation examples. (author)

Transient performance of EBR-II driver fuel

International Nuclear Information System (INIS)

Buzzell, J.A.; Hudman, G.D.; Porter, D.L.

1981-01-01

The first phases of qualification of the EBR-II driver fuel for repeated transient overpower operation have recently been completed. The accomplishments include prediction of the transient fuel and cladding performance through ex-core testing and fuel-element modeling studies, localized in-core power testing during steady-state operation, and whole-core multiple transient testing. The metallic driver fuel successfully survived 56 transients, spaced over a 45-day period, with power increases of approx. 160% at rates of approx. 1%/s with a 720-second hold at full power. The performance results obtained from both ex-core and n-core tests indicate that the fuel is capable of repeated transient operation

Transient thermal effect, nonlinear refraction and nonlinear absorption properties of graphene oxide sheets in dispersion.

Science.gov (United States)

Zhang, Xiao-Liang; Liu, Zhi-Bo; Li, Xiao-Chun; Ma, Qiang; Chen, Xu-Dong; Tian, Jian-Guo; Xu, Yan-Fei; Chen, Yong-Sheng

2013-03-25

The nonlinear refraction (NLR) properties of graphene oxide (GO) in N, N-Dimethylformamide (DMF) was studied in nanosecond, picosecond and femtosecond time regimes by Z-scan technique. Results show that the dispersion of GO in DMF exhibits negative NLR properties in nanosecond time regime, which is mainly attributed to transient thermal effect in the dispersion. The dispersion also exhibits negative NLR in picosecond and femtosecond time regimes, which are arising from sp(2)- hybridized carbon domains and sp(3)- hybridized matrix in GO sheets. To illustrate the relations between NLR and nonlinear absorption (NLA), NLA properties of the dispersion were also studied in nanosecond, picosecond and femtosecond time regimes.

Sodium oxide and uranium oxide aerosol experiments: NSPP Tests 106-108 and Tests 204-207, data record report

Energy Technology Data Exchange (ETDEWEB)

Adams, R.E.; Kress, T.S.; Tobias, M.L.

1981-03-01

This data record report describes three sodium oxide aerosol tests and four uranium oxide aerosol tests conducted in the Nuclear Safety Pilot Plant project at Oak Ridge National Laboratory. The goal of this project is to establish the validity (or level of conservatism) of the aerosol behavioral code, HAARM-3, and follow-on codes under development at the Battelle Columbus Laboratories for the US Nuclear Regulatory Commission. Descriptions of the seven tests with tables and graphs summarizing the results are included. 92 figs.

Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase*

Science.gov (United States)

Mishanina, Tatiana V.; Yadav, Pramod K.; Ballou, David P.; Banerjee, Ruma

2015-01-01

The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be −123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. PMID:26318450

Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase.

Science.gov (United States)

Mishanina, Tatiana V; Yadav, Pramod K; Ballou, David P; Banerjee, Ruma

2015-10-09

The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be -123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

5-HMF attenuates striatum oxidative damage via Nrf2/ARE signaling pathway following transient global cerebral ischemia.

Science.gov (United States)

Ya, Bai-Liu; Li, Hong-Fang; Wang, Hai-Ying; Wu, Fei; Xin, Qing; Cheng, Hong-Ju; Li, Wen-Juan; Lin, Na; Ba, Zai-Hua; Zhang, Ru-Juan; Liu, Qian; Li, Ya-Nan; Bai, Bo; Ge, Feng

2017-01-01

Recent studies have shown 5-hydroxymethyl-2-furfural (5-HMF) has favorable biological effects, and its neuroprotection in a variety of neurological diseases has been noted. Our previous study showed that treatment of 5-HMF led to protection against permanent global cerebral ischemia. However, the underlying mechanisms in cerebral ischemic injury are not fully understood. This study was conducted to investigate the neuroprotective effect of 5-HMF and elucidate the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway mechanism in the striatum after transient global cerebral ischemia. C57BL/6 mice were subjected to bilateral common carotid artery occlusion for 20 min and sacrificed 24 h after reperfusion. 5-HMF (12 mg/kg) or an equal volume of vehicle was intraperitoneally injected 30 min before ischemia and 5 min after the onset of reperfusion. At 24 h after reperfusion, neurological function was evaluated by neurological disability status scale, locomotor activity test and inclined beam walking test. Histological injury of the striatum was observed by cresyl violet staining and terminal deoxynucleotidyl transferase (TdT)-mediated dNTP nick end labeling (TUNEL) staining. Oxidative stress was evaluated by the carbonyl groups introduced into proteins, and malondialdehyde (MDA) levels. An enzyme-linked immunosorbent assay (ELISA)-based measurement was used to detect Nrf2 DNA binding activity. Nrf2 and its downstream ARE pathway protein expression such as heme oxygenase-1, NAD (P)H:quinone oxidoreductase 1, glutamate-cysteine ligase catalytic subunit and glutamate-cysteine ligase modulatory subunit were detected by western blot. Our results showed that 5-HMF treatment significantly ameliorated neurological deficits, reduced brain water content, attenuated striatum neuronal damage, decreased the carbonyl groups and MDA levels, and activated Nrf2/ARE signaling pathway. Taken together, these results demonstrated that

The roles of EBR-II and TREAT [Transient Reactor Test] in establishing liquid metal reactor safety

International Nuclear Information System (INIS)

Sackett, J.I.; Lehto, W.K.; Solbrig, C.W.

1990-01-01

This paper examines the role of the Experimental Breeder Reactor II (EBR-II) and Transient Reactor Test (TREAT) facilities in contributing to the understanding and resolution of key safety issues in liquid metal reactor safety during the decade of the 80's. Fuels and materials testing has been carried out to address questions on fuels behavior during steady-state and upset conditions. In addition, EBR-II has conducted plant tests to demonstrate passive response to ATWS events and to develop control and diagnostic strategies for safe operation of advanced LMRs. TREAT and EBR-II complement each other and between them provide a transient testing capability that covers the whole range of concerns during overpower conditions. EBR-II, with use of the special Automatic Control Rod Drive System, can generate power change rates that overlap the lower end of the TREAT capability. 21 refs

Development of Electrical Capacitance Sensors for Accident Tolerant Fuel (ATF) Testing at the Transient Reactor Test (TREAT) Facility

Energy Technology Data Exchange (ETDEWEB)

Liu, Maolong; Ryals, Matthew; Ali, Amir; Blandford, Edward; Jensen, Colby; Condie, Keith; Svoboda, John; O' Brien, Robert

2016-08-01

A variety of instruments are being developed and qualified to support the Accident Tolerant Fuels (ATF) program and future transient irradiations at the Transient Reactor Test (TREAT) facility at Idaho National Laboratory (INL). The University of New Mexico (UNM) is working with INL to develop capacitance-based void sensors for determining the timing of critical boiling phenomena in static capsule fuel testing and the volume-averaged void fraction in flow-boiling in-pile water loop fuel testing. The static capsule sensor developed at INL is a plate-type configuration, while UNM is utilizing a ring-type capacitance sensor. Each sensor design has been theoretically and experimentally investigated at INL and UNM. Experiments are being performed at INL in an autoclave to investigate the performance of these sensors under representative Pressurized Water Reactor (PWR) conditions in a static capsule. Experiments have been performed at UNM using air-water two-phase flow to determine the sensitivity and time response of the capacitance sensor under a flow boiling configuration. Initial measurements from the capacitance sensor have demonstrated the validity of the concept to enable real-time measurement of void fraction. The next steps include designing the cabling interface with the flow loop at UNM for Reactivity Initiated Accident (RIA) ATF testing at TREAT and further characterization of the measurement response for each sensor under varying conditions by experiments and modeling.

Analysis of fuel pin behavior under slow-ramp type transient overpower condition by using the fuel performance evaluation code 'FEMAXI-FBR'

International Nuclear Information System (INIS)

Tsuboi, Yasushi; Ninokata, Hisashi; Endo, Hiroshi; Ishizu, Tomoko; Tatewaki, Isao; Saito, Hiroaki

2012-01-01

FEMAXI-FBR has been developed as the one module of the core disruptive accident analysis code 'ASTERIA-FBR' in order to evaluate the mixed oxide (MOX) fuel performance under steady, transient and accident conditions of fast reactors consistently. On the basis of light water reactor (LWR) fuel performance evaluation code 'FEMAXI-6', FEMAXI-FBR develops specific models for the fast reactor fuel performance, such as restructuring, material migration during steady state and transient, melting cavity formation and pressure during accident, so that it can evaluate the fuel failure during accident. The analysis of test pin with slow transient over power test of CABRI-2 program was conducted from steady to transient. The test pin was pre-irradiated and tested under transient overpower with several % P 0 /s (P 0 : steady state power) of the power rate. Analysis results of the gas release ratio, pin failure time, and fuel melt radius were compared to measured values. The analysis results of the steady and transient performances were also compared with the measured values. The compared performances are gas release ratio, fuel restructuring for steady state and linear power and melt radius at failure during transient. This analysis result reproduces the measured value. It was concluded that FEMAXI-FBR is effective to evaluate fast reactor fuel performances from steady state to accident conditions. (author)

Steam Oxidation Testing in the Severe Accident Test Station

Energy Technology Data Exchange (ETDEWEB)

Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-08-01

After the March 2011 accident at Fukushima Daiichi, Oak Ridge National Laboratory (ORNL) began conducting high temperature steam oxidation testing of candidate materials for accident tolerant fuel (ATF) cladding in August 2011 [1-11]. The ATF concept is to enhance safety margins in light water reactors (LWR) during severe accident scenarios by identifying materials with 100× slower steam oxidation rates compared to current Zr-based alloys. In 2012, the ORNL laboratory equipment was expanded and made available to the entire ATF community as the Severe Accident Test Station (SATS) [4,12]. Compared to the current UO2/Zr-based alloy fuel system, an ATF alternative would significantly reduce the rate of heat and hydrogen generation in the core during a coolant-limited severe accident [13-14]. The steam oxidation behavior of candidate materials is a key metric in the evaluation of ATF concepts and also an important input into models [15-17]. However, initial modeling work of FeCrAl cladding has used incomplete information on the physical properties of FeCrAl. Also, the steam oxidation data being collected at 1200°-1700°C is unique as no prior work has considered steam oxidation of alloys at such high temperatures. Also, because many accident scenarios include steadily increasing temperatures, the required data are not traditional isothermal exposures but exposures with varying “ramp” rates. In some cases, the steam oxidation behavior has been surprising and difficult to interpret. Thus, more fundamental information continues to be collected. In addition, more work continues to focus on commercially-manufactured tube material. This report summarizes recent work to characterize the behavior of candidate alloys exposed to high temperature steam, evaluate steam oxidation behavior in various ramp scenarios and continue to collect integral data on FeCrAl compared to conventional Zr-based cladding.

Vivitron 1995, transient voltage simulation, high voltage insulator tests, electric field calculation

International Nuclear Information System (INIS)

Frick, G.; Osswald, F.; Heusch, B.

1996-01-01

Preliminary investigations showed clearly that, because of the discrete electrode structure of the Vivitron, important overvoltage leading to insulator damage can appear in case of a spark. The first high voltage tests showed damage connected with such events. This fact leads to a severe voltage limitation. This work describes, at first, studies made to understand the effects of transients and the associated over-voltage appearing in the Vivitron. Then we present the high voltage tests made with full size Vivitron components using the CN 6 MV machine as a pilot machine. Extensive field calculations were made. These involve simulations of static stresses and transient overvoltages, on insulating boards and electrodes. This work gave us the solutions for arrangements and modifications in the machine. After application, the Vivitron runs now without any sparks and damage at 20 MV. In the same manner, we tested column insulators of a new design and so we will find out how to get to higher voltages. Electric field calculation around the tie bars connecting the discrete electrodes together showed field enhancements when the voltages applied on the discrete electrodes are not equally distributed. This fact is one of the sources of discharges and voltage limitations. A scenario of a spark event is described and indications are given how to proceed towards higher voltages, in the 30 MV range. (orig.)

Sextant: an expert system for transient analysis of nuclear reactors and integral test facilities

International Nuclear Information System (INIS)

Barbet, N.; Dumas, M.; Mihelich, G.

1987-01-01

Expert systems provide a new way of dealing with the computer-aided management of nuclear plants by combining several knowledge bases and reasoning modes together with a set of numerical models for real-time analysis of transients. New development tools are required together with metaknowledge bases handling temporal hypothetical reasoning and planning. They have to be efficient and robust because during a transient, neither measurements nor models, nor scenarios are hold as absolute references. SEXTANT is a general purpose physical analyzer intended to provide a pattern and avoid duplication of general tools and knowledge bases for similar applications. It combines several knowledge bases concerning measurements, models and qualitative behavior of PWR with a mechanism of conjecture-refutation and a set of simplified models matching the current physical state. A prototype is under assessment by dealing with integral test facility transients. For its development, SEXTANT requires a powerful shell. SPIRAL is such a toolkit, oriented towards online analysis of complex processes and already used in several applications

Transient photoconductivity and femtosecond nonlinear optical properties of a conjugated polymer-graphene oxide composite

Energy Technology Data Exchange (ETDEWEB)

Nalla, Venkatram; Ji Wei [Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Polavarapu, Lakshminarayana; Manga, Kiran Kumar; Goh, Bee Min; Loh, Kian Ping; Xu Qinghua, E-mail: chmxqh@nus.edu.sg, E-mail: phyjiwei@nus.edu.sg [Department of Chemistry, National University of Singapore, Singapore 117543 (Singapore)

2010-10-15

A water soluble conjugated thiophene polymer, sodium salt of poly[2-(3-thienyl)ethoxy-4-butylsulfonate] (TPP), and graphene oxide (GO) composite film (GO-TPP) device was prepared. Transient photoconductivity measurements were carried out on the GO-TPP composite film using 150 ns laser pulses of 527 nm wavelength. Highly efficient photocurrent generation was observed from the GO-TPP film. The relationships of the film photoconductivity, photocurrent decay time and electron decay times with the incident light intensity were investigated. The photoconductive gain of the film was determined to be greater than 40% and to be independent of the light intensity. Furthermore, the femtosecond nonlinear optical properties of the GO-TPP film were measured using 800 nm femtosecond laser pulses and the composite film exhibited high nonlinear absorption and nonlinear refraction coefficients.

Transient photoconductivity and femtosecond nonlinear optical properties of a conjugated polymer-graphene oxide composite

International Nuclear Information System (INIS)

Nalla, Venkatram; Ji Wei; Polavarapu, Lakshminarayana; Manga, Kiran Kumar; Goh, Bee Min; Loh, Kian Ping; Xu Qinghua

2010-01-01

A water soluble conjugated thiophene polymer, sodium salt of poly[2-(3-thienyl)ethoxy-4-butylsulfonate] (TPP), and graphene oxide (GO) composite film (GO-TPP) device was prepared. Transient photoconductivity measurements were carried out on the GO-TPP composite film using 150 ns laser pulses of 527 nm wavelength. Highly efficient photocurrent generation was observed from the GO-TPP film. The relationships of the film photoconductivity, photocurrent decay time and electron decay times with the incident light intensity were investigated. The photoconductive gain of the film was determined to be greater than 40% and to be independent of the light intensity. Furthermore, the femtosecond nonlinear optical properties of the GO-TPP film were measured using 800 nm femtosecond laser pulses and the composite film exhibited high nonlinear absorption and nonlinear refraction coefficients.

Power-Cooling-Mismatch Test Series. Test PCM-2: postirradiation examination

International Nuclear Information System (INIS)

Seiffert, S.L.

1977-03-01

The report describes the results of the postirradiation examination of four 0.91-m long pressurized water reactor (PWR) type, UO 2 -fueled zircaloy-clad fuel rods tested in an in-pile experimental investigation of pre- and post-departure from nucleate boiling (DNB) behavior of previously unirradiated fuel rods. None of the four fuel rods tested failed during testing or during reactor shut down. Visual and metallographic examination of the individual fuel rods indicated that the length of the high temperature zone of film boiling varied from rod to rod. Two of the four fuel rods showed evidence of damage by film boiling, characterized by oxide spalling and cladding collapse. Metallographic examination of these fuel rods showed internal cladding oxidation resulting from fuel-cladding reaction. Cladding embrittlement by oxidation is evaluated. A comparison of the cladding surface temperatures estimated metallographically for the separate fuel rods with cladding surface temperatures measured during testing and calculated from the Fuel Rod Analysis Program-Transient (FRAP-T) computer code is included

Classification methods for noise transients in advanced gravitational-wave detectors II: performance tests on Advanced LIGO data

International Nuclear Information System (INIS)

Powell, Jade; Heng, Ik Siong; Torres-Forné, Alejandro; Font, José A; Lynch, Ryan; Trifirò, Daniele; Cuoco, Elena; Cavaglià, Marco

2017-01-01

The data taken by the advanced LIGO and Virgo gravitational-wave detectors contains short duration noise transients that limit the significance of astrophysical detections and reduce the duty cycle of the instruments. As the advanced detectors are reaching sensitivity levels that allow for multiple detections of astrophysical gravitational-wave sources it is crucial to achieve a fast and accurate characterization of non-astrophysical transient noise shortly after it occurs in the detectors. Previously we presented three methods for the classification of transient noise sources. They are Principal Component Analysis for Transients (PCAT), Principal Component LALInference Burst (PC-LIB) and Wavelet Detection Filter with Machine Learning (WDF-ML). In this study we carry out the first performance tests of these algorithms on gravitational-wave data from the Advanced LIGO detectors. We use the data taken between the 3rd of June 2015 and the 14th of June 2015 during the 7th engineering run (ER7), and outline the improvements made to increase the performance and lower the latency of the algorithms on real data. This work provides an important test for understanding the performance of these methods on real, non stationary data in preparation for the second advanced gravitational-wave detector observation run, planned for later this year. We show that all methods can classify transients in non stationary data with a high level of accuracy and show the benefits of using multiple classifiers. (paper)

Steady-state and transient fission gas release and swelling model for LIFE-4

International Nuclear Information System (INIS)

Villalobos, A.; Liu, Y.Y.; Rest, J.

1984-06-01

The fuel-pin modeling code LIFE-4 and the mechanistic fission gas behavior model FASTGRASS have been coupled and verified against gas release data from mixed-oxide fuels which were transient tested in the TREAT reactor. Design of the interface between LIFE-4 and FASTGRASS is based on an earlier coupling between an LWR version of LIFE and the GRASS-SST code. Fission gas behavior can significantly affect steady-state and transient fuel performance. FASTGRASS treats fission gas release and swelling in an internally consistent manner and simultaneously includes all major mechanisms thought to influence fission gas behavior. The FASTGRASS steady-state and transient analysis has evolved through comparisons of code predictions with fission-gas release and swelling data from both in- and ex-reactor experiments. FASTGRASS was chosen over other fission-gas behavior models because of its availability, its compatibility with the LIFE-4 calculational framework, and its predictive capability

Coincident steam generator tube rupture and stuck-open safety relief valve carryover tests: MB-2 steam generator transient response test program

International Nuclear Information System (INIS)

Garbett, K.; Mendler, O.J.; Gardner, G.C.; Garnsey, R.; Young, M.Y.

1987-03-01

In PWR steam generator tube rupture (SGTR) faults, a direct pathway for the release of radioactive fission products can exist if there is a coincident stuck-open safety relief valve (SORV) or if the safety relief valve is cycled. In addition to the release of fission products from the bulk steam generator water by moisture carryover, there exists the possibility that some primary coolant may be released without having first mixed with the bulk water - a process called primary coolant bypassing. The MB-2 Phase II test program was designed specifically to identify the processes for droplet carryover during SGTR faults and to provide data of sufficient accuracy for use in developing physical models and computer codes to describe activity release. The test program consisted of sixteen separate tests designed to cover a range of steady-state and transient fault conditions. These included a full SGTR/SORV transient simulation, two SGTR overfill tests, ten steady-state SGTR tests at water levels ranging from very low levels in the bundle up to those when the dryer was flooded, and three moisture carryover tests without SGTR. In these tests the influence of break location and the effect of bypassing the dryer were also studied. In a final test the behavior with respect to aerosol particles in a dry steam generator, appropriate to a severe accident fault, was investigated

Transient productivity index for numerical well test simulations

Energy Technology Data Exchange (ETDEWEB)

Blanc, G.; Ding, D.Y.; Ene, A. [Institut Francais du Petrole, Pau (France)] [and others

1997-08-01

The most difficult aspect of numerical simulation of well tests is the treatment of the Bottom Hole Flowing (BHF) Pressure. In full field simulations, this pressure is derived from the Well-block Pressure (WBP) using a numerical productivity index which accounts for the grid size and permeability, and for the well completion. This productivity index is calculated assuming a pseudo-steady state flow regime in the vicinity of the well and is therefore constant during the well production period. Such a pseudo-steady state assumption is no longer valid for the early time of a well test simulation as long as the pressure perturbation has not reached several grid-blocks around the well. This paper offers two different solutions to this problem: (1) The first one is based on the derivation of a Numerical Transient Productivity Index (NTPI) to be applied to Cartesian grids; (2) The second one is based on the use of a Corrected Transmissibility and Accumulation Term (CTAT) in the flow equation. The representation of the pressure behavior given by both solutions is far more accurate than the conventional one as shown by several validation examples which are presented in the following pages.

Fuel cladding mechanical properties for transient analysis

International Nuclear Information System (INIS)

Johnson, G.D.; Hunter, C.W.; Hanson, J.E.

1976-01-01

Out-of-pile simulated transient tests have been conducted on irradiated fast-reactor fuel pin cladding specimens at heating rates of 10 0 F/s (5.6 0 K/s) and 200 0 F/s (111 0 K/s) to generate mechanical property information for use in describing cladding behavior during off-normal events. Mechanical property data were then analyzed, applying the Larson-Miller Parameter to the effects of heating rate and neutron fluence. Data from simulated transient tests on TREAT-tested fuel pins demonstrate that Plant Protective System termination of 3$/s transients prevents significant damage to cladding. The breach opening produced during simulated transient testing is shown to decrease in size with increasing neutron fluence

Flow transients experiments with refrigerant-12

International Nuclear Information System (INIS)

Celata, G.P.; D'Annibale, F.; Farello, G.E.; Setaro, T.

1986-01-01

Flow transients have been investigated in a wide range of thermal-hydraulics situations with Refrigerannt-12. Six pressures (including the reference to PWR and BWR characteristic liquid to vapour densities ratios), several periods of the flowrate transients coastdown during the simulated flow decays, and different specific mass flowrate have been studied emploiyng a circular duct test section (Dsub(i)=7,5 mm). Two heated lengths of the test section have been considered (L = 2300 and 1180 mm). Experimental data have shown the complete inadequacy of steady-state critical heat flux correlations in predicting the onset of boiling crisis during fast flow transients (half-flow decay time, tsub(h)lt5.0-6.0 s). The flow transient does not show dependence, in terms of DNB conditions ,upon the length of the test section: the ratio between transient and steady-state critical mass flowrate is not dependent on the tested geometry. The time interval from the start of the flowrate transient to the onset of DNB (time to crisis), has been experimentally determined for all the runs. Data analysis for a better theoretical prediction of the phenomenon has been accomplished, and a design correlation for DNB conditons and time to crisis prediction has been proposed

Comparison of in-plant performance test data with analytic prediction of reactor safety system injection transient (U)

International Nuclear Information System (INIS)

Roy, B.N.; Neill, C.H. Jr.

1993-01-01

This paper compares the performance test data from injection transients for both of the subsystems of the Supplementary Safety System of the Savannah River Site production reactor with analytical predictions from an in-house thermal hydraulic computer code. The code was initially developed for design validation of the new Supplementary Safety System subsystem, but is shown to be equally capable of predicting the performance of the Supplementary Safety System existing subsystem even though the two subsystem transient injections have marked differences. The code itself was discussed and its validation using prototypic tests with simulated fluids was reported in an earlier paper (Roy and Nomm 1991)

Behavior of metallic uranium-fissium fuel in TREAT transient overpower tests

International Nuclear Information System (INIS)

Bauer, T.H.; Klickman, A.E.; Lo, R.K.; Rhodes, E.A.; Robinson, W.R.; Stanford, G.S.; Wright, A.E.

1986-01-01

TREAT tests M2, M3, and M4 were performed to obtain information on two key behavior characteristics of fuel under transient overpower accident conditions in metal-fueled fast reactors: the prefailure axial self-extrusion (elongation beyond thermal expansion) of fuel within intact cladding and the margin to cladding breach. Uranium-5 wt% fissium Experimental Breeder Reactor-II driver fuel pins were used for the tests since they were available as suitable stand-ins for the uranium-plutonium-zirconium ternary fuel, which is the reference fuel of the integral fast reactor (IFR) concept. The ternary fuel will be used in subsequent TREAT tests. Preliminary results from tests M2 and M3 were presented earlier. The present report includes significant advances in analysis as well as additional data from test M4. Test results and analysis have led to the development and validation of pin cladding failure and fuel extrusion models for metallic fuel, within reasonable uncertainties for the uranium-fissium alloy. Concepts involved are straightforward and readily extendable to ternary alloys and behavior in full-size reactors

Failure analysis of carbide fuels under transient overpower (TOP) conditions

International Nuclear Information System (INIS)

Nguyen, D.H.

1980-06-01

The failure of carbide fuels in the Fast Test Reactor (FTR) under Transient Overpower (TOP) conditions has been examined. The Beginning-of-Cycle Four (BOC-4) all-oxide base case, at $.50/sec ramp rate was selected as the reference case. A coupling between the advanced fuel performance code UNCLE-T and HCDA Code MELT-IIIA was necessary for the analysis. UNCLE-T was used to determine cladding failure and fuel preconditioning which served as initial conditions for MELT-III calculations. MELT-IIIA determined the time of molten fuel ejection from fuel pin

Volume 1. Base technology FSAR support document: prefailure transient behavior and failure threshold. Status report, January 1975

International Nuclear Information System (INIS)

Baars, R.E.; Culley, G.E.; Davis, R.T.; Henderson, R.G.; Scott, J.H.

1975-11-01

A comprehensive compilation of the current (January 1975) state-of-the-art understanding of fuel pin response to reactivity insertion events up to and including failure threshold is presented. All mixed oxide fuel, transient overpower tests conducted to date are described and the data collected therein are presented. Current understanding of fuel pin cladding failure mechanisms is discussed, and interpretations of fuel pin cladding failure thresholds are presented as revealed by individual tests and by the several tests collectively. Plans for future tests are discussed

First TREAT transient overpower tests on U-Pu-Zr fuel: M5 and M6

International Nuclear Information System (INIS)

Robinson, W.R.; Bauer, T.H.; Wright, A.E.; Rhodes, E.A.; Stanford, G.S.; Klickman, A.E.

1987-01-01

Transient Reactor Test Facility (TREAT) tests M5 and M6 were the first transient overpower (TOP) test of the margin to cladding breach and prefailure elongation of metallic U-Pu-Zr ternary fuel, the reference fuel of the integral fast reactor concept. Similar tests on U-5 wt% Fs fueled Experimental Breeder Reactor (EBR)-II driver pins were previously performed and reported. Results from these earlier tests indicated a margin to failure of ∼ 4 times nominal power and significant axial elongation prior to failure, a feature that was very pronounced at low burnups. While these two fuels types are similar in many respects, the ternary alloy exhibits a much more complex physical structure and is typically irradiated at much higher temperatures. Thus, a prime motivation for performing M5 and M6 was to compare the safety-related fuel performance characteristics of U-Fs and U-Pu-Zr. Tests M5 and M6 indicate that, under the TOP conditions used in the tests, ternary fuel displayed about the same margin to failure as U-Fs fuel. At low burnups, ternary fuel showed less prefailure axial elongation than observed in U-Fs pins, but elongations of 3 to 5% might turn out to be typical. Finally, fuel from the breached ternary pin in M6 showed, qualitatively, the same benignly dispersive behavior as U-Fs

Axial location of cladding failure during a slow transient overpower TREAT test

International Nuclear Information System (INIS)

Page, R.J.; Murphy, W.F.; Holland, J.W.

1983-01-01

The axial location of cladding failure following a transient overpower accident is of importance in fast reactor safety studies in that it is a determining factor in the relocation of fuel, and therefore in the possibility of inherent neutronic shutdown of the reactor. In-pile experimental data on the axial location of cladding failure of fuel in bundles of pins is sparse since, in general, the experimental fuel pin bundles are largely destroyed during the in-pile test. The post-test examination work has been completed for TREAT test J1. It was found that damage to the fuel elements during the irradiation was low enough for an accurate observation of the location of cladding failure to be made for each of the seven pins

Neuronal-like differentiated SH-SY5Y cells adaptation to a mild and transient H2 O2 -induced oxidative stress.

Science.gov (United States)

Akki, Rachid; Siracusa, Rosalba; Morabito, Rossana; Remigante, Alessia; Campolo, Michela; Errami, Mohammed; La Spada, Giuseppina; Cuzzocrea, Salvatore; Marino, Angela

2018-03-01

Preconditioning (PC) is a cell adaptive response to oxidative stress and, with regard to neurons, can be considered as a neuroprotective strategy. The aim of the present study was to verify how neuronal-like differentiated SH-SY5Y cells adapt to a mild and transient H 2 O 2 -induced oxidative stress and, hence, whether may be considered as more sensitive cell model to study PC pathways. A first screening allowed to define H 2 O 2 concentrations for PC (10μM-50μM), applied before damage(100μM H 2 O 2 ). Cell viability measured 24 hours after 100μM H 2 O 2 -induced damage was ameliorated by 24-hour pre-exposure to low-concentration H 2 O 2 (10μM-30μM) with cell size as well restored. Markers for apoptosis (Bcl-2 and Bad), inflammation (iNOS), and redox system (MnSOD) were also determined, showing that, in cells pre-exposed to 10μM H 2 O 2 and then submitted to 100μM H 2 O 2 , Bcl-2 levels were higher, Bad and iNOS levels were lower than those observed in damaged cells, and MnSOD levels were unchanged. Such findings show that (1) neuronal-like differentiated SH-SY5Y cells are a suitable model to investigate PC response and more sensitive to the effect of a mild and transient H 2 O 2 -induced oxidative stress with respect to other neuronal cells; (2) 10μM H 2 O 2 -induced PC is mediated by apoptotic and inflammatory pathways, unlike antioxidant system; (3) such neuroprotective strategy and underlying signals proven in neuronal-like differentiated SH-SY5Y cells may contribute to understand in vivo PC mechanisms and to define a window for pharmacological intervention, namely, related to ischemic brain damage. Neuronal-like differentiated SH-SY5Y cells are a suitable model to investigate PC, an endogenous neuroprotective response to a mild and transient H 2 O 2 -induced oxidative stress, elicited by 24-hour exposure to very low H 2 O 2 concentrations and mediated by both apoptotic and inflammatory pathways. This model reflects in vivo PC mechanisms occurring

78 FR 6400 - Results of FAA Nitrous Oxide BLEVE Characterization Testing

Science.gov (United States)

2013-01-30

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Results of FAA Nitrous Oxide BLEVE Characterization Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of public... FAA sponsored testing of nitrous oxide (N 2 O) characteristics. Nitrous oxide is an important oxidizer...

Numerical Analysis of S-CO{sub 2} Test Loop Transient Conditions near the Critical Point of CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Bae, Seong Jun; Oh, Bongseong; Ahn, Yoonhan; Baik, Seongjoon; Lee, Jekyoung; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

2016-05-15

It was identified that controlling CO{sub 2} compressor operation near the critical point is one of the most important issues to operate a S-CO{sub 2} Brayton cycle with a high efficiency. Despite the growing interest in the S-CO{sub 2} Brayton cycle, a few previous research on the transient analysis of the S-CO{sub 2} system has been conducted previously. Moreover, previous studies have some limitation in the modelled test facility, and the experiment was not performed to observe specific scenario. The KAIST research team has conducted S-CO{sub 2} system transient experiments with the CO{sub 2} compressing test facility called SCO{sub 2}PE (Supercritical CO{sub 2} Pressurizing Experiment) at KAIST In this study, authors use the transient analysis code GAMMA (Gas Multidimensional Multicomponent mixture Analysis) code for analyzing the experiment. Two transient scenarios were selected in this study; over cooling and under cooling situations. The selected transient situation is of particular interest since the compressor inlet conditions start to drift away from the critical point of CO{sub 2}. The results represent that the GAMMA code can simulate the S-CO{sub 2} test facility, SCO{sub 2}PE. However, as shown in the cooling water flow rate increasing scenario, the GAMMA code shows calculation error when the phase change occurs. Furthermore, although the results of the cooling water flow rate decrease case shows reasonable agreement with the experimental data, there are still some unexplained differences between the experimental data and the GAMMA code prediction.

Oxidation characteristics of the electron beam surface-treated Alloy 617 in high temperature helium environments

International Nuclear Information System (INIS)

Lee, Ho Jung; Sah, Injin; Kim, Donghoon; Kim, Hyunmyung; Jang, Changheui

2015-01-01

The oxidation characteristics of the electron beam surface-treated Alloy 617, which has an Al-rich surface layer, were evaluated in high temperature helium environments. Isothermal oxidation tests were performed in helium (99.999% purity) and VHTR-helium (helium of prototypical VHTR chemistry containing impurities like CO, CO 2 , CH 4 , and H 2 ) environments at 900 °C for up to 1000 h. The surface-treated Alloy 617 showed an initial transient oxidation stage followed by the steady-state oxidation in all test environments. In addition, the steady-state oxidation kinetics of the surface-treated Alloy 617 was 2-order of magnitude lower than that of the as-received Alloy 617 in both helium environments as well as in air. The improvement in oxidation resistance was primarily due to the formation of the protective Al 2 O 3 layer on the surface. The weight gain was larger in the order of air, helium, and VHTR-helium, while the parabolic rate constants (k p ) at steady-state were similar for all test environments. In both helium environments, the oxide structure consisted of the outer transition Al 2 O 3 with a small amount of Cr 2 O 3 and inner columnar structured Al 2 O 3 without an internal oxide. In the VHTR-helium environment, where the impurities were added to helium, the initial transient oxidation increased but the steady state kinetics was not affected

Interim results from UO2 fuel oxidation tests in air

International Nuclear Information System (INIS)

Campbell, T.K.; Gilbert, E.R.; Thornhill, C.K.; White, G.D.; Piepel, G.F.; Griffin, C.W.j.

1987-08-01

An experimental program is being conducted at Pacific Northwest Laboratory (PNL) to extend the characterization of spent fuel oxidation in air. To characterize oxidation behavior of irradiated UO 2 , fuel oxidation tests were performed on declad light-water reactor spent fuel and nonirradited UO 2 pellets in the temperature range of 135 to 250 0 C. These tests were designed to determine the important independent variables that might affect spent fuel oxidation behavior. The data from this program, when combined with the test results from other programs, will be used to develop recommended spent fuel dry-storage temperature limits in air. This report describes interim test results. The initial PNL investigations of nonirradiated and spent fuels identified the important testing variables as temperature, fuel burnup, radiolysis of the air, fuel microstructure, and moisture in the air. Based on these initial results, a more extensive statistically designed test matrix was developed to study the effects of temperature, burnup, and moisture on the oxidation behavior of spent fuel. Oxidation tests were initiated using both boiling-water reactor and pressurized-water reactor fuels from several different reactors with burnups from 8 to 34 GWd/MTU. A 10 5 R/h gamma field was applied to the test ovens to simulate dry storage cask conditions. Nonirradiated fuel was included as a control. This report describes experimental results from the initial tests on both the spent and nonirradiated fuels and results to date on the tests in a 10 5 R/h gamma field. 33 refs., 51 figs., 6 tabs

Results of transient overpower events on breached and unbreached fuel pins

International Nuclear Information System (INIS)

Strain, R.V.; Tsai, H.C.; Neimark, L.A.; Aratani, K.

1986-04-01

The objective of the extended overpower tests on intact pins was to determine the pin cladding breaching thresholds vis-a-vis the Plant Protection System (PPS) trip settings, typically at ∼10 to 15% overpower. These tests emphasize slow operational-type transients in light of earlier work which suggested that irradiated mixed-oxide fuel pins may be particularly vulnerable in the slow ramp-rate regime. An overview of the extended overpower test series was previously reported. More recent results on two of the tests in this series are included in this paper. These two tests, designated TOPI-1A and TOPI-1B, were each conducted on a 19-pin assembly with various pin design, operation and burnup variables. The overpower ramp rates for the TOPI-1A and -1B tests were 0.1%/s and 10%/s, respectively

Mechanism of propylene oxidation over bismuth molybdate revealed by transient response method--1. An intermediate in the complete oxidation of C/sub 3/H/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, M.; Futaya, R.

1979-01-01

An intermediate in the complete oxidation of C/sub 3/H/sub 6/ and its nature were deduced from transient response studies of a flow reactor system with a 1:1 bismuth-molybdenum catalyst at temperatures below ordinary operating temperatures. The formation of a stable surface intermediate with a non-allylic structure resembling that of propylene on every site of the catalyst surface occurred at 310/sup 0/C in the presence of propylene/oxygen or acrolein/oxygen; under oxidative conditions at 310/sup 0/C about eight times more intermediate formed directly from propylene than from adsorbed acrolein. The intermediate reacted with weakly adsorbed oxygen from the gas phase, but not with lattice oxygen, to decompose into CO/sub 2/; in temperature programed desorption studies (2.3/sup 0/C/min) it desorbed as CO/sub 2/ into a stream of helium above 220/sup 0/C (peak at 420/sup 0/C), apparently by reaction with oxygen diffused from the bulk to the surface.

Analysis of incoloy 800ht alloy tested in thermal transient conditions

International Nuclear Information System (INIS)

Velciu, L.; Meleg, T.; Nitu, A.; Popa, L.

2015-01-01

This paper investigated Incoloy 800 HT alloy after following thermal transient tests: fast heating rates (50° and 90°C/minute) up to 1,000°C, maintaining this temperature level (0 and 60 minutes), furnace-cooling until 220°C, and then air-cooling. This alloy is one of the candidate materials for construction of the steam generators of the future NPP reactors. The analysis consisted in metallographic examination and traction tests. The samples were investigated using the Olympus GX 71 optical microscope, the OPL microdurometer with automatic cycle and WALTER BAI traction device. The average grain size was determined by linear interception method. The micro hardness was calculated by the relationship from the device technical book. On the traction diagrams were obtained: strength resistance (Rm), elongation at rupture (A) and elastic modulus (E). The tested alloy was compared with the ''as received'' material, and the results showed a good behavior of this alloy in the presented conditions. (authors)

Simulation of the transient behaviour of the Mulheim-Karlich nuclear power station and comparison with startup tests

International Nuclear Information System (INIS)

Burchhardt, W.; Weber, J.P.

1987-01-01

Among the startup tests of the Mulheim-Karlich nuclear power station an anticipated turbine trip and a rector trip have been performed. Calculations have been done for both tests by the authors using the computer codes DYNODE-P and ALMOD4. At a given reactor power the transient behavior of the plant is determined by the heat load of the once-through steam generators (OTSG), which in turn is governed by the integral control system. As expected the behavior of the plant after the trips can be exactly reproduced only if the bypass control system is completely modelled. In addition the heat transfer to the secondary side of the OTSG which governs the steam production has to be calculated close to reality. comparing the calculated results with the measured test data it is demonstrated that either code can be used to reproduce the transient behavior of the plant

Experimental data report for transient flow calibration facility tests IIB101, IIB102 and IIB201

International Nuclear Information System (INIS)

Wambach, J.L.

1980-01-01

Thermal-hydraulic response data are presented for the transient performance tests of a pitot tube rake (IIB201) and a modular drag disc-turbine transducer (DTT) rake (IIB101, IIB102). The tests were conducted in a system which provided full scale simulation of the pressure vessel and broken loop hot leg piping of the Loss of Fluid Test Facility (LOFT). A load cell system was used to provide a reference mass flow rate measurement

A study of the transient performance of hydrostatic journal bearings. I - Test apparatus and facility

Science.gov (United States)

Scharrer, J. K.; Tellier, J.; Hibbs, R.

1992-10-01

A test apparatus was developed for studies of the transient performance of hydrostatic journal bearings operating in liquid nitrogen. The data obtained give the number of revolutions of the shaft contact before the liftoff and after touchdown as a function of bearing/shaft material combinations and operating conditions.

Irradiation test plan of oxidation-resistant graphite in WWR-K Research Reactor

International Nuclear Information System (INIS)

Sumita, Junya; Shibata, Taiju; Sakaba, Nariaki; Osaki, Hirotaka; Kato, Hideki; Fujitsuka, Kunihiro; Muto, Takenori; Gizatulin, Shamil; Shaimerdenov, Asset; Dyussambayev, Daulet; Chakrov, Petr

2014-01-01

Graphite materials are used for the in-core components of High Temperature Gas-cooled Reactor (HTGR) which is a graphite-moderated and helium gas-cooled reactor. In the case of air ingress accident in HTGR, SiO_2 protective layer is formed on the surface of SiC layer in TRISO CFP and oxidation of SiC does not proceed and fission products are retained inside the fuel particle. A new safety concept for the HTGR, called Naturally Safe HTGR, has been recently proposed. To enhance the safety of Naturally Safe HTGR ultimately, it is expected that oxidation-resistant graphite is used for graphite components to prevent the TRISO CFPs and fuel compacts from failure. SiC coating is one of candidate methods for oxidation-resistant graphite. JAEA and four graphite companies launched R&Ds to develop the oxidation-resistant graphite and the International Science and Technology Center (ISTC) partner project with JAEA and INP was launched to investigate the irradiation effects on the oxidation-resistant graphite. To determine grades of the oxidation-resistant graphite which will be adopted as irradiation test, a preliminary oxidation test was carried out. This paper described the results of the preliminary oxidation test, the plan of out-of-pile test, irradiation test and post-irradiation test (PIE) of the oxidation-resistant graphite. The results of the preliminary oxidation test showed that the integrity of the oxidation resistant graphite was confirmed and that all of grades used in the preliminary test can be adopted as the irradiation test. Target irradiation temperature was determined to be 1473 (K) and neutron fluence was determined to be from 0.54 × 10"2"5through 1.4 × 10"2"5 (/m"2, E>0.18MeV). Weight change, oxidation rate, activation energy, surface condition, etc. will be evaluated in out-of-pile test and weight change, irradiation effect on oxidation rate and activation energy, surface condition, etc. will be evaluated in PIE. (author)

Positive patch test reactions to oxidized limonene

DEFF Research Database (Denmark)

Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus

2014-01-01

to oxidized R-limonene. OBJECTIVE: To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis. METHODS: Oxidized R-limonene 3.0% (containing limonene...... hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed. RESULTS: Overall, exposure to products containing limonene was found...

Measurement and analysis of transient vaporization in oxide fuel materials

International Nuclear Information System (INIS)

Gorham-Bergeron, E.; Benson, D.A.

1978-01-01

A series of experiments is described in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressures measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical nonequilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented

HEDL experimental transient overpower program

International Nuclear Information System (INIS)

Hikido, T.; Culley, G.E.

1976-01-01

HEDL is conducting a series of experiments to evaluate the performance of Fast Flux Test Facility (FFTF) prototypic fuel pins up to the point of cladding breach. A primary objective of the program is to demonstrate the adequacy of fuel pin and Plant Protective System (PPS) designs for terminated transients. Transient tests of prototypic FFTF fuel pins previously irradiated in the Experimental Breeder Reactor-II (EBR-II) have demonstrated the adequacy of the PPS and fuel pin designs and indicate that a very substantial margin exists between PPS-terminated transients and that required to produce fuel pin cladding failure. Additional experiments are planned to extend the data base to high burnup, high fluence fuel pin specimens

Development of a test facility for analyzing transients in supercritical water-cooled reactors by fractional scaling analysis

Energy Technology Data Exchange (ETDEWEB)

Roberto, Thiago D., E-mail: thiagodbtr@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN—RJ), Rua Hélio de Almeida, 75 21941-972, Rio de Janeiro Caixa-Postal: 68550, RJ (Brazil); Silva, Mário A. B. da, E-mail: mabs500@gmail.com [Departamento de Energia Nuclear (CTG/UFPE), Av. Professor Luiz Freire, 1000, Recife 50740-540, PE (Brazil); Lapa, Celso M.F., E-mail: lapa@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN—RJ), Rua Hélio de Almeida, 75 21941-972, Rio de Janeiro Caixa-Postal: 68550, RJ (Brazil)

2016-01-15

The feasibility of performing experiments using water under supercritical conditions is limited by technical and financial difficulties. These difficulties can be overcome by using model fluids that are characterized by feasible supercritical conditions, that is, lower critical pressure and critical temperature. Experimental investigations are normally used to determine the conditions under which model fluids reliably represent supercritical fluids under steady-state conditions. A fluid-to-fluid scaling approach has been proposed to determine the model fluids that represent supercritical fluids in a transient state. Recently, a similar technique known as fractional scaling analysis was developed to establish the conditions under which experiments can be performed using models that represent transients in prototypes. This paper presents a fractional scaling analysis application to determine parameters for a test facility in which transient conditions in supercritical water-cooled reactors are simulated by using carbon dioxide as a model fluid, whose critical point conditions are more feasible than those of water. Similarity is obtained between water (prototype) and carbon dioxide (model) by depressurization in a simple vessel. The main parameters required for the construction of a future test facility are obtained using the proposed method.

Development of a test facility for analyzing transients in supercritical water-cooled reactors by fractional scaling analysis

International Nuclear Information System (INIS)

Roberto, Thiago D.; Silva, Mário A. B. da; Lapa, Celso M.F.

2016-01-01

The feasibility of performing experiments using water under supercritical conditions is limited by technical and financial difficulties. These difficulties can be overcome by using model fluids that are characterized by feasible supercritical conditions, that is, lower critical pressure and critical temperature. Experimental investigations are normally used to determine the conditions under which model fluids reliably represent supercritical fluids under steady-state conditions. A fluid-to-fluid scaling approach has been proposed to determine the model fluids that represent supercritical fluids in a transient state. Recently, a similar technique known as fractional scaling analysis was developed to establish the conditions under which experiments can be performed using models that represent transients in prototypes. This paper presents a fractional scaling analysis application to determine parameters for a test facility in which transient conditions in supercritical water-cooled reactors are simulated by using carbon dioxide as a model fluid, whose critical point conditions are more feasible than those of water. Similarity is obtained between water (prototype) and carbon dioxide (model) by depressurization in a simple vessel. The main parameters required for the construction of a future test facility are obtained using the proposed method.

Heat and mass release for some transient fuel source fires: A test report

International Nuclear Information System (INIS)

Nowlen, S.P.

1986-10-01

Nine fire tests using five different trash fuel source packages were conducted by Sandia National Laboratories. This report presents the findings of these tests. Data reported includes heat and mass release rates, total heat and mass release, plume temperatures, and average fuel heat of combustion. These tests were conducted as a part of the US Nuclear Regulatory Commission sponsored fire safety research program. Data from these tests were intended for use in nuclear power plant probabilistic risk assessment fire analyses. The results were also used as input to a fire test program at Sandia investigating the vulnerability of electrical control cabinets to fire. The fuel packages tested were chosen to be representative of small to moderately sized transient trash fuel sources of the type that would be found in a nuclear power plant. The highest fire intensity encountered during these tests was 145 kW. Plume temperatures did not exceed 820 0 C

Measurement and analysis of transient vaporization in oxide fuel materials

International Nuclear Information System (INIS)

Benson, D.A.; Bergeron, E.G.

1979-01-01

This paper describes a series of experiments in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressure measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical non-equilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented. (orig.) [de

Transient flow combustion

Science.gov (United States)

Tacina, R. R.

1984-01-01

Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

Characterizing SI Engine Transient Fuel Consumption in ALPHA

Science.gov (United States)

Examine typical transient engine operation encountered over the EPA's vehicle and engine testing drive cycles to characterize that transient fuel usage, and then describe the changes made to ALPHA to better model transient engine operation.

Determining oxide trapped charges in Al2O3 insulating films on recessed AlGaN/GaN heterostructures by gate capacitance transients measurements

Science.gov (United States)

Fiorenza, Patrick; Greco, Giuseppe; Schilirò, Emanuela; Iucolano, Ferdinando; Lo Nigro, Raffaella; Roccaforte, Fabrizio

2018-05-01

This letter presents time-dependent gate-capacitance transient measurements (C–t) to determine the oxide trapped charges (N ot) in Al2O3 films deposited on recessed AlGaN/GaN heterostructures. The C–t transients acquired at different temperatures under strong accumulation allowed to accurately monitor the gradual electron trapping, while hindering the re-emission by fast traps that may affect conventional C–V hysteresis measurements. Using this method, an increase of N ot from 2 to 6 × 1012 cm‑2 was estimated between 25 and 150 °C. The electron trapping is ruled by an Arrhenius dependence with an activation energy of 0.12 eV which was associated to points defects present in the Al2O3 films.

Models for transient analyses in advanced test reactors

International Nuclear Information System (INIS)

Gabrielli, Fabrizio

2011-01-01

Several strategies are developed worldwide to respond to the world's increasing demand for electricity. Modern nuclear facilities are under construction or in the planning phase. In parallel, advanced nuclear reactor concepts are being developed to achieve sustainability, minimize waste, and ensure uranium resources. To optimize the performance of components (fuels and structures) of these systems, significant efforts are under way to design new Material Test Reactors facilities in Europe which employ water as a coolant. Safety provisions and the analyses of severe accidents are key points in the determination of sound designs. In this frame, the SIMMER multiphysics code systems is a very attractive tool as it can simulate transients and phenomena within and beyond the design basis in a tightly coupled way. This thesis is primarily focused upon the extension of the SIMMER multigroup cross-sections processing scheme (based on the Bondarenko method) for a proper heterogeneity treatment in the analyses of water-cooled thermal neutron systems. Since the SIMMER code was originally developed for liquid metal-cooled fast reactors analyses, the effect of heterogeneity had been neglected. As a result, the application of the code to water-cooled systems leads to a significant overestimation of the reactivity feedbacks and in turn to non-conservative results. To treat the heterogeneity, the multigroup cross-sections should be computed by properly taking account of the resonance self-shielding effects and the fine intra-cell flux distribution in space group-wise. In this thesis, significant improvements of the SIMMER cross-section processing scheme are described. A new formulation of the background cross-section, based on the Bell and Wigner correlations, is introduced and pre-calculated reduction factors (Effective Mean Chord Lengths) are used to take proper account of the resonance self-shielding effects of non-fuel isotopes. Moreover, pre-calculated parameters are applied

High temperature oxidation test of oxide dispersion strengthened (ODS) steel claddings

International Nuclear Information System (INIS)

Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

2006-07-01

In a feasibility study of ODS steel cladding, its high temperature oxidation resistance was evaluated. Although addition of Cr is effective for preventing high temperature oxidation, excessively higher amount of Cr leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, high temperature oxidation test was conducted for ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) 9Cr-ODS martensitic and 12Cr-ODS ferritic steel have superior high temperature oxidation resistance compared to 11mass%Cr PNC-FMS and even 17mass% SUS430 and equivalent to austenitic PNC316. (2) The superior oxidation resistance of ODS steel was attributed to earlier formation of the protective alpha-Cr 2 O 3 layer at the matrix and inner oxide scale interface. The grain size of ODS steel is finer than that of PNC-FMS, so the superior oxidation resistance of ODS steel can be attributed to the enhanced Cr-supplying rate throughout the accelerated grain boundary diffusion. Finely dispersed Y 2 O 3 oxide particles in the ODS steel matrix may also stabilized the adherence between the protective alpha-Cr 2 O 3 layer and the matrix. (author)

Standard test methods for analysis of sintered gadolinium oxide-uranium dioxide pellets

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Section Carbon (Total) by Direct CombustionThermal Conductivity Method C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Gadolinia Content by Energy-Dispersive X-Ray Spectrometry C1456 Test Method for Determination of Uranium or Gadolinium, or Both, in Gadolinium Oxide-Uranium Oxide Pellets or by X-Ray Fluorescence (XRF) Hydrogen by Inert Gas Fusion C1457 Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction Isotopic Uranium Composition by Multiple-Filament Surface-Ioni...

Comparison of a fission-gas effects in a transient overpower test (HUT 5-7A) to FRAS3 code predictions

International Nuclear Information System (INIS)

Gruber, E.E.; Randklev, E.H.

1979-01-01

Fission gas has an important bearing on fuel dynamics during reactor transients. Fission-gas bubble sizes and densities, both within grains and on grain boundaries, are characterized as functions of radial location at the axial midplane in studies of PNL-9 fuel microstructures before and after the HUT 5-7A (PNL 9-25) TREAT test. The FRAS3 code, being developed to model fission-gas effects in reactor transients, is applied to analyze the results of the HUT 5-7A test are presented to illustrate the observed phenomena and the validity of the modeling approach

Transmitter modulation of spike-evoked calcium transients in arousal related neurons

DEFF Research Database (Denmark)

Kohlmeier, Kristi Anne; Leonard, Christopher S

2006-01-01

Nitric oxide synthase (NOS)-containing cholinergic neurons in the laterodorsal tegmentum (LDT) influence behavioral and motivational states through their projections to the thalamus, ventral tegmental area and a brainstem 'rapid eye movement (REM)-induction' site. Action potential-evoked intracel......Nitric oxide synthase (NOS)-containing cholinergic neurons in the laterodorsal tegmentum (LDT) influence behavioral and motivational states through their projections to the thalamus, ventral tegmental area and a brainstem 'rapid eye movement (REM)-induction' site. Action potential......-evoked intracellular calcium transients dampen excitability and stimulate NO production in these neurons. In this study, we investigated the action of several arousal-related neurotransmitters and the role of specific calcium channels in these LDT Ca(2+)-transients by simultaneous whole-cell recording and calcium...... of cholinergic LDT neurons and that inhibition of spike-evoked Ca(2+)-transients is a common action of neurotransmitters that also activate GIRK channels in these neurons. Because spike-evoked calcium influx dampens excitability, our findings suggest that these 'inhibitory' transmitters could boost firing rate...

Tucurui`s 500 kV S F{sub 6} gas-insulated substation modeling for fast transients - field tests comparison

Energy Technology Data Exchange (ETDEWEB)

Lima Filho, Joao Ferreira de; Pazo Blanco, Flavio A.F.; D` Ajuz, Ary; Nascimento, Lidio F.A. [ELETRONORTE, Brasilia, DF (Brazil)

1994-12-31

Many problems in insulation, devices and equipment have been resulted from switching operations in the 500 kV Gas-Insulated Substation (GIS) of Tucurui power plant. Disconnector closing or opening action can subject the GIS components to great stresses from excessive voltages at high frequencies caused by successive reflections of travelling waves at discontinuities (1,2,3). Field tests were carried out in September 18-23, 1991 to verify the actual GIS stresses at Tucurui. From these results simulations on the Alternative Transients Program (ATP) were performed in order to check the substation modeling. This paper presents and discusses the Tucurui GIS modeling for switching fast transients and its field test validation. (author) 8 refs., 6 figs.

Modelling of the partial oxidation of {alpha}, {beta}-unsaturated aldehydes on Mo-V-oxides based catalysts

Energy Technology Data Exchange (ETDEWEB)

Boehnke, H.; Petzoldt, J.C.; Stein, B.; Weimer, C.; Gaube, J.W. [Technische Univ. Darmstadt (Germany). Inst. fuer Chemische Technologie

1998-12-31

A kinetic model based on the Mars-van Krevelen mechanism that allows to describe the microkinetics of the heterogeneously catalysed partial oxidation of {alpha}, {beta}-unsaturated aldehydes is presented. This conversion is represented by a network, composed of the oxidation of the {alpha}, {beta}-unsaturated aldehyde towards the {alpha}, {beta}-unsaturated carboxylic acid and the consecutive oxidation of the acid as well as the parallel reaction of the aldehyde to products of deeper oxidation. The reaction steps of aldehyde respectively acid oxidation and catalyst reoxidation have been investigated separately in transient experiments. The combination of steady state and transient experiments has led to an improved understanding of the interaction of the catalyst with the aldehyde and the carboxylic acids as well as to a support of the kinetic model assumptions. (orig.)

Behavior of a VVER fuel element tested under severe accident conditions in the CORA facility. Test results of experiment CORA-W1

International Nuclear Information System (INIS)

Hagen, S.; Hofmann, P.; Noack, V.; Schanz, G.; Schumacher, G.; Sepold, L.

1994-01-01

Test bundle CORA-W1 was without absorber material. As in the earlier CORA tests the test bundles were subjected to temperature transients of a slow heatup rate in a steam environment. The transient phases of the test were initiated with a temperature ramp rate of 1 K/s. With these conditions a so-called small-break LOCA was simulated. The temperature escalation due to the exothermal zirconium/niobium-steam reaction started at about 1200 C, leading the bundle to a maximum temperature of approximately 1900 C. With the movement of the melt also heat is transported to the lower region. Below 300 mm elevation the test bundle remained intact due to the axial temeprature distribution. W2 ist characterized by a strong oxidation above 300 mm elevation. Besides the severe oxidation the test bundle resulted in considerable fuel dissolution by ZrNb1/UO 2 interaction in the upper part, complete spacer destruction at 600 mm due to chemical interactions between steel and the ZSrNb1 cladding. Despite some specific features the material behavior of the VVER-1000 bundle is comparable to that observed in the PWR and BWR test using fuel elements typical for Western countries. (orig./HP) [de

Supercritical water oxidation data acquisition testing. Final report, Volume I

International Nuclear Information System (INIS)

1996-11-01

This report discusses the phase one testing of a data acquisition system for a supercritical water waste oxidation system. The system is designed to destroy a wide range of organic materials in mixed wastes. The design and testing of the MODAR Oxidizer is discussed. An analysis of the optimized runs is included

Transient kinetics of carbon monoxide oxidation by oxygen over supported palladium/ceria/zirconia three-way catalysts in the absence and presence of water and carbon dioxide

NARCIS (Netherlands)

Rajasree, R.; Hoebink, J.H.B.J.; Schouten, J.C.

2004-01-01

The transient kinetics of CO oxidation by O2 over alumina-supported Pd/CeO2/ZrO2 three-way catalysts is described in the absence and presence of H2O and CO2 in the feed. Experiments were carried out in a laboratory fixed-bed reactor at 573 K, while periodically switching between a feed of 1 vol% CO

Severe transient tests on operation steam generators: Analysis of the fluid structure dynamic thermal interaction

International Nuclear Information System (INIS)

Billon, F.; David, J.; Procaccia, H.

1983-01-01

The operating efficiency of steam generators (S.G.s) and their structural integrity depend on the design configurations of the feedwater spray within the S.G., and on the operating procedure. To check the merit of some design modifications, and to verify the fluid-structure interaction with a view to preserve the S.G.s integrity during severe operating transients, a special instrumentation that admits the determination of the instantaneous thermal hydraulic characteristics of the flow in the secondary water and the S.G. tube sheet, has been installed by EDF on one steam generator of Tricastin unit 1 power plant. In parallel, FRAMATOME has developped a computer code, TEMPTRON, that allows the calculations of the thermal loads and the consequent stresses in the most sollicited zones of the steam generator during transient operation of the plant. This code divides the S.G. into three parts: - the first concerns the S.G.s region above the downcomer, zone where the mixing between hot water and cold feedwater occurs, - the second is the downcomer itself which is divided into n segments, - the third concerns the tube sheet zone which is also divided into n segments. The most severe transient test performed is the auxiliary cold feedwater injection into the steam generator during a hot standby of the plant: two levels of flow rate have been realised: 55 and 110 m 3 /h of 42 0 C feedwater. The tests have shown that if the cold feedwater injection occurs when the steam generator water level is below feedwater ring, the lowest fluid temperature reached at tube sheet inlet is about 230 0 C. (orig.)

Application of transient analysis methodology to heat exchanger performance monitoring

International Nuclear Information System (INIS)

Rampall, I.; Soler, A.I.; Singh, K.P.; Scott, B.H.

1994-01-01

A transient testing technique is developed to evaluate the thermal performance of industrial scale heat exchangers. A Galerkin-based numerical method with a choice of spectral basis elements to account for spatial temperature variations in heat exchangers is developed to solve the transient heat exchanger model equations. Testing a heat exchanger in the transient state may be the only viable alternative where conventional steady state testing procedures are impossible or infeasible. For example, this methodology is particularly suited to the determination of fouling levels in component cooling water system heat exchangers in nuclear power plants. The heat load on these so-called component coolers under steady state conditions is too small to permit meaningful testing. An adequate heat load develops immediately after a reactor shutdown when the exchanger inlet temperatures are highly time-dependent. The application of the analysis methodology is illustrated herein with reference to an in-situ transient testing carried out at a nuclear power plant. The method, however, is applicable to any transient testing application

Creep-rupture, steam oxidation and recovery behaviours upon dynamic transients up to 1300 C of cold-worked 304 stainless steel tubes dedicated to nuclear core fuel cladding

International Nuclear Information System (INIS)

Portier, L.; Brachet, J.C.; Vandenberghe, V.; Guilbert, T.; Lezaud-Chaillioux, V.; Bernard, C.; Rabeau, V.

2011-01-01

An ambitious mechanical tests program was conducted on the fuel rod cladding of the CABRI facility between 2004 and 2009 to re-evaluate the cladding tubes materials behaviour. As an offspring of this major scientific investment several conclusions of interest could be drawn on the 304 stainless steel material. In particular, the specific behaviour of the materials during hypothetical and extreme 'dry-out' conditions was investigated. In such a scenario, the cladding tube materials should experience a very brief incursion at high temperatures, in a steam environment, up to 1300 C, before cladding rewetting. Some of the measurements performed in the range of interest for the safety case were on purpose developed beyond the conservatively safe domain. Some of the results obtained for these non-conventional heating rates, pressures and temperature ranges will be presented. First in order to assess the high temperature creep-rupture material behaviour under internal pressure upon dynamic transient conditions, tests have been performed on cold-worked 304 stainless cladding tubes in a steam environment, for heating rates up to 100 C*s -1 and pressure ramp rates up to 10 bar*s -1 thanks to the use of the EDGAR facility. Other tests performed at a given pressure allowed us to check the steady-state secondary creep rate of the materials in the 1100-1200 C temperature range. It was also possible to determine the rupture strength value and the failure mode as a function of the thermal and pressure loading history applied. It is worth noticing that, for very specific conditions, a surprising pure intergranular brittle failure mode of the clad has been observed. Secondly, in order to check the materials oxidation resistance of the materials, two-side steam oxidation tests have been performed at 1300 C, using the DEZIROX facility. It was shown that, thanks to the use of Ring Compression tests, the 304 cladding tube keeps significant ductility for oxidation times up to at least

FRESS pin failure model and its application to E-8 TREAT test

International Nuclear Information System (INIS)

Kalimullah.

1979-01-01

FRESS is a cladding rupture prediction model for an irradiated mixed-oxide LMFBR fuel pin during transient heating based only on the internal pressurization of the cladding by the fission gas released from fuel grains during the transient. The model is applied to the analysis of the hottest PNL-10-53 pin in the 7-pin E-8 TREAT test which simulates a $3/sec transient overpower. Although the uncertainties of the inputs to the temperature calculation done with the COBRA code have not been included, the uncertain input parameters to FRESS have been varied over their estimated uncertainties. The cladding rupture predictions are a few tens of milliseconds late compared to the most probable failure time detected in the test. However, these calculations seem to indicate that fisson gas pressure is a significant mechanism for causing clad rupture in this test

Transient dynamic finite element analysis of hydrogen distribution test chamber structure for hydrogen combustion loads

International Nuclear Information System (INIS)

Singh, R.K.; Redlinger, R.; Breitung, W.

2005-09-01

Design and analysis of blast resistant structures is an important area of safety research in nuclear, aerospace, chemical process and vehicle industries. Institute for Nuclear and Energy Technologies (IKET) of Research Centre- Karlsruhe (Forschungszentrum Karlsruhe or FZK) in Germany is pursuing active research on the entire spectrum of safety evaluation for efficient hydrogen management in case of the postulated design basis and beyond the design basis severe accidents for nuclear and non-nuclear applications. This report concentrates on the consequence analysis of hydrogen combustion accidents with emphasis on the structural safety assessment. The transient finite element simulation results obtained for 2gm, 4gm, 8gm and 16gm hydrogen combustion experiments concluded recently on the test-cell structure are described. The frequencies and damping of the test-cell observed during the hammer tests and the combustion experiments are used for the present three dimensional finite element model qualification. For the numerical transient dynamic evaluation of the test-cell structure, the pressure time history data computed with CFD code COM-3D is used for the four combustion experiments. Detail comparisons of the present numerical results for the four combustion experiments with the observed time signals are carried out to evaluate the structural connection behavior. For all the combustion experiments excellent agreement is noted for the computed accelerations and displacements at the standard transducer locations, where the measurements were made during the different combustion tests. In addition inelastic analysis is also presented for the test-cell structure to evaluate the limiting impulsive and quasi-static pressure loads. These results are used to evaluate the response of the test cell structure for the postulated over pressurization of the test-cell due to the blast load generated in case of 64 gm hydrogen ignition for which additional sets of computations were

Experimental Setup with Transient Behavior of Fuel Cladding of SFR

Energy Technology Data Exchange (ETDEWEB)

Shin, Sang Hun; Kim, Jun Hwan; Kim, June-Hyung; Ryu, Woo Seog; Park, Sang Gyu; Kim, Sung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

Nowadays, in Korea, advanced cladding such as FC92 is developed and its transient behaviors are required for the safety analysis of SFR. Design and safety analyses of sodium-cooled fast reactor (SFR) require understanding fuel pin responses to a wide range of off-normal events. In a loss-of-flow (LOF) or transient over-power (TOP), the temperature of the cladding is rapidly increased above its steady-state service temperature. Transient tests have been performed in sections of fuel pin cladding and a large data base has been established for austenitic stainless steel such as 20% cold-worked 316 SS and ferritic/martensitic steels such as HT9. This paper summarizes the technical status of transient testing facilities and their results. Previous researches showed the transient behaviors of HT9 cladding. For the safety analyses in SFR in Korea, simulated transient tests with newly developed FC92 as well as HT9 cladding are being carried out.

Pre-test analysis of protected loss of primary pump transients in CIRCE-HERO facility

Science.gov (United States)

Narcisi, V.; Giannetti, F.; Del Nevo, A.; Tarantino, M.; Caruso, G.

2017-11-01

In the frame of LEADER project (Lead-cooled European Advanced Demonstration Reactor), a new configuration of the steam generator for ALFRED (Advanced Lead Fast Reactor European Demonstrator) was proposed. The new concept is a super-heated steam generator, double wall bayonet tube type with leakage monitoring [1]. In order to support the new steam generator concept, in the framework of Horizon 2020 SESAME project (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors), the ENEA CIRCE pool facility will be refurbished to host the HERO (Heavy liquid mEtal pRessurized water cOoled tubes) test section to investigate a bundle of seven full scale bayonet tubes in ALFRED-like thermal hydraulics conditions. The aim of this work is to verify thermo-fluid dynamic performance of HERO during the transition from nominal to natural circulation condition. The simulations have been performed with RELAP5-3D© by using the validated geometrical model of the previous CIRCE-ICE test section [2], in which the preceding heat exchanger has been replaced by the new bayonet bundle model. Several calculations have been carried out to identify thermal hydraulics performance in different steady state conditions. The previous calculations represent the starting points of transient tests aimed at investigating the operation in natural circulation. The transient tests consist of the protected loss of primary pump, obtained by reducing feed-water mass flow to simulate the activation of DHR (Decay Heat Removal) system, and of the loss of DHR function in hot conditions, where feed-water mass flow rate is absent. According to simulations, in nominal conditions, HERO bayonet bundle offers excellent thermal hydraulic behavior and, moreover, it allows the operation in natural circulation.

Transient trimethylaminuria related to menstruation

Science.gov (United States)

Shimizu, Makiko; Cashman, John R; Yamazaki, Hiroshi

2007-01-01

Background Trimethylaminuria, or fish odor syndrome, includes a transient or mild malodor caused by an excessive amount of malodorous trimethylamine as a result of body secretions. Herein, we describe data to support the proposal that menses can be an additional factor causing transient trimethylaminuria in self-reported subjects suffering from malodor and even in healthy women harboring functionally active flavin-containing monooxygenase 3 (FMO3). Methods FMO3 metabolic capacity (conversion of trimethylamine to trimethylamine N-oxide) was defined as the urinary ratio of trimethylamine N-oxide to total trimethylamine. Results Self-reported Case (A) that was homozygous for inactive Arg500stop FMO3, showed decreased metabolic capacity of FMO3 (i.e., ~10% the unaffected metabolic capacity) during 120 days of observation. For Case (B) that was homozygous for common [Glu158Lys; Glu308Gly] FMO3 polymorphisms, metabolic capacity of FMO3 was almost ~90%, except for a few days surrounding menstruation showing 90%) metabolic capacity, however, on days around menstruation the FMO3 metabolic capacity was decreased to ~60–70%. Conclusion Together, these results indicate that abnormal FMO3 capacity is caused by menstruation particularly in the presence, in homozygous form, of mild genetic variants such as [Glu158Lys; Glu308Gly] that cause a reduced FMO3 function. PMID:17257434

Transient burnout in flow reduction condition

International Nuclear Information System (INIS)

Iwamura, Takamichi; Kuroyanagi, Toshiyuki

1981-01-01

A transient flow reduction burnout experiment was conducted with water in a uniformly heated, vertically oriented tube. Test pressures ranged from 0.5 to 3.9 MPa. An analytical method was developed to obtain transient burnout conditions at the exit. A simple correlation to predict the deviation of the transient burnout mass velocity at the tube exit from the steady state mass velocity obtained as a function of steam-water density ratio and flow reduction rate. The correlation was also compared with the other data. (author)

The development of the fuel rod transient performance analysis code FTPAC

International Nuclear Information System (INIS)

Han Zhijie; Ji Songtao

2014-01-01

Fuel rod behavior, especially the integrity of cladding, played an important role in fuel safety research during reactor transient and hypothetical accidents conditions. In order to study fuel rod performance under transient accidents, FTPAC (Fuel Transient Performance Analysis Code) has been developed for simulating light water reactor fuel rod transient behavior when power or coolant boundary conditions are rapidly changing. It is composed of temperature, mechanical deformation, cladding oxidation and gas pressure model. The assessment was performed by comparing FTPAC code analysis result to experiments data and FRAPTRAN code calculations. Comparison shows that, the FTPAC gives reasonable agreement in temperature, deformation and gas pressure prediction. And the application of slip coefficient is more suitable for simulating the sliding between pellet and cladding when the gap is closed. (authors)

Passive safety testing at the Fast Flux Test Facility

International Nuclear Information System (INIS)

Lucoff, D.M.

1989-01-01

During 1986, the Fast Flux Test Facility (FFTF) conducted several tests designed to improve the understanding of the passive safety characteristics of an oxide-fueled liquid-metal reactor (LMR). Static and dynamic tests were performed over a broad range of power, flow, and temperature conditions that extended beyond those for normal operation. Key results of these tests are presented. Stable operation at low power with natural circulation cooling was demonstrated. A passive safety enhancement feature, the gas expansion module (GEM) was developed specifically to offset the large amount of cooldown reactivity that needs to be controlled in an oxide-fueled LMR undergoing an unprotected loss-of-flow accident. Nine GEMs were built and successfully tested in FFTF. With the reactor at 50% power (200 MW (thermal)), the main coolant pumps were turned off and the normal control rod scram response was inhibited. The GEMs and inherent core reactivity feedback mechanisms took the core subcritical with a modest peak coolant temperature transient that reached 85 degrees C above the pretransient value and always maintained a >400 degrees C margin to the sodium boiling point (910 degrees C)

Predictive tests to evaluate oxidative potential of engineered nanomaterials

Science.gov (United States)

Ghiazza, Mara; Carella, Emanuele; Oliaro-Bosso, Simonetta; Corazzari, Ingrid; Viola, Franca; Fenoglio, Ivana

2013-04-01

Oxidative stress constitutes one of the principal injury mechanisms through which particulate toxicants (asbestos, crystalline silica, hard metals) and engineered nanomaterials can induce adverse health effects. ROS may be generated indirectly by activated cells and/or directly at the surface of the material. The occurrence of these processes depends upon the type of material. Many authors have recently demonstrated that metal oxides and carbon-based nanoparticles may influence (increasing or decreasing) the generation of oxygen radicals in a cell environment. Metal oxide, such as iron oxides, crystalline silica, and titanium dioxide are able to generate free radicals via different mechanisms causing an imbalance within oxidant species. The increase of ROS species may lead to inflammatory responses and in some cases to the development of cancer. On the other hand carbon-based nanomaterials, such as fullerene, carbon nanotubes, carbon black as well as cerium dioxide are able to scavenge the free radicals generated acting as antioxidant. The high numbers of new-engineered nanomaterials, which are introduced in the market, are exponentially increasing. Therefore the definition of toxicological strategies is urgently needed. The development of acellular screening tests will make possible the reduction of the number of in vitro and in vivo tests to be performed. An integrated protocol that may be used to predict the oxidant/antioxidant potential of engineered nanoparticles will be here presented.

Predictive tests to evaluate oxidative potential of engineered nanomaterials

International Nuclear Information System (INIS)

Ghiazza, Mara; Carella, Emanuele; Corazzari, Ingrid; Fenoglio, Ivana; Oliaro-Bosso, Simonetta; Viola, Franca

2013-01-01

Oxidative stress constitutes one of the principal injury mechanisms through which particulate toxicants (asbestos, crystalline silica, hard metals) and engineered nanomaterials can induce adverse health effects. ROS may be generated indirectly by activated cells and/or directly at the surface of the material. The occurrence of these processes depends upon the type of material. Many authors have recently demonstrated that metal oxides and carbon-based nanoparticles may influence (increasing or decreasing) the generation of oxygen radicals in a cell environment. Metal oxide, such as iron oxides, crystalline silica, and titanium dioxide are able to generate free radicals via different mechanisms causing an imbalance within oxidant species. The increase of ROS species may lead to inflammatory responses and in some cases to the development of cancer. On the other hand carbon-based nanomaterials, such as fullerene, carbon nanotubes, carbon black as well as cerium dioxide are able to scavenge the free radicals generated acting as antioxidant. The high numbers of new-engineered nanomaterials, which are introduced in the market, are exponentially increasing. Therefore the definition of toxicological strategies is urgently needed. The development of acellular screening tests will make possible the reduction of the number of in vitro and in vivo tests to be performed. An integrated protocol that may be used to predict the oxidant/antioxidant potential of engineered nanoparticles will be here presented.

LOFT/L9-3, Loss of Fluid Test, Anticipated Transients with Multiple Failures

International Nuclear Information System (INIS)

1992-01-01

1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: This was the third of the NRC L9 series of experiments on Anticipated Transients with Multiple Failures. Loss-of-feedwater effects were studied. The experiment was conducted on 7 April 1982

LOFT/L6-7, Loss of Fluid Test, Anticipated Transients with Multiple Failures

International Nuclear Information System (INIS)

1992-01-01

1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: This was the seventh in the NRC L6 Series of Anticipated Transients experiments. Rapid secondary side induced cooldown was studied. The experiment was conducted on 31 September 1981

ORNL rod-bundle heat-transfer test data. Volume 3. Thermal-hydraulic test facility experimental data report for test 3.06.6B - transient film boiling in upflow

International Nuclear Information System (INIS)

Mullins, C.B.; Felde, D.K.; Sutton, A.G.; Gould, S.S.; Morris, D.G.; Robinson, J.J.

1982-05-01

Reduced instrument responses are presented for Thermal-Hyraulic Test Facility (THTF) Test 3.06.6B. This test was conducted by members of the Oak Ridge National Laboratory Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer (BDHT) Separate-Effects Program on August 29, 1980. The objective of the program was to investigate heat transfer phenomena believed to occur in PWR's during accidents, including small and large break loss-of-coolant accidents. Test 3.06.6B was conducted to obtain transient film boiling data in rod bundle geometry under reactor accident-type conditions. The primary purpose of this report is to make the reduced instrument responses for THTF Test 3.06.6B available. Included in the report are uncertainties in the instrument responses, calculated mass flows, and calculated rod powers

Nuclear reactors transients identification and classification system; Sistema de identificacao e classificacao de transientes em reatores nucleares

Energy Technology Data Exchange (ETDEWEB)

Bianchi, Paulo Henrique

2008-07-01

This work describes the study and test of a system capable to identify and classify transients in thermo-hydraulic systems, using a neural network technique of the self-organizing maps (SOM) type, with the objective of implanting it on the new generations of nuclear reactors. The technique developed in this work consists on the use of multiple networks to do the classification and identification of the transient states, being each network a specialist at one respective transient of the system, that compete with each other using the quantization error, that is a measure given by this type of neural network. This technique showed very promising characteristics that allow the development of new functionalities in future projects. One of these characteristics consists on the potential of each network, besides responding what transient is in course, could give additional information about that transient. (author)

Instrumented Taylor anvil-on-rod impact tests for validating applicability of standard strength models to transient deformation states

Science.gov (United States)

Eakins, D. E.; Thadhani, N. N.

2006-10-01

Instrumented Taylor anvil-on-rod impact tests have been conducted on oxygen-free electronic copper to validate the accuracy of current strength models for predicting transient states during dynamic deformation events. The experiments coupled the use of high-speed digital photography to record the transient deformation states and laser interferometry to monitor the sample back (free surface) velocity as a measure of the elastic/plastic wave propagation through the sample length. Numerical continuum dynamics simulations of the impact and plastic wave propagation employing the Johnson-Cook [Proceedings of the Seventh International Symposium on Ballistics, 1983, The Netherlands (Am. Def. Prep. Assoc. (ADPA)), pp. 541-547], Zerilli-Armstrong [J. Appl. Phys. C1, 1816 (1987)], and Steinberg-Guinan [J. Appl. Phys. 51, 1498 (1980)] constitutive equations were used to generate transient deformation profiles and the free surface velocity traces. While these simulations showed good correlation with the measured free surface velocity traces and the final deformed sample shape, varying degrees of deviations were observed between the photographed and calculated specimen profiles at intermediate deformation states. The results illustrate the usefulness of the instrumented Taylor anvil-on-rod impact technique for validating constitutive equations that can describe the path-dependent deformation response and can therefore predict the transient and final deformation states.

LWR fuel performance during anticipated transients with scram

International Nuclear Information System (INIS)

Martinson, Z.R.; McCardell, R.K.; MacDonanl, P.E.; Rowland, T.C.; Tokar, M.

1983-01-01

Operational transients occur occasionally in light water reactors when minor malfunctions of certain system components affect the reactor core. Potential effects of such malfunctions include a loss of the secondary heat sink, an increase in system pressure, and, in boiling water reactors, void collapse and a brief increase in reactor power. The most severe postulated Boiling Water Reactor (BWR) anticipated transient is characterized by a power peak of up to 495% rated power for about 1 second (according to a recent General Electric Co., generic analysis). The results of a series of fuel behaviour tests in the Power Burst Facility (PBF) at the Idaho National Engineering Laboratory are presented in this paper. Four progressively higher and broader power transients at a constant coolant flow rate were performed. The first transient simulated a BWR-5 turbine trip without steam bypass with fuel rods operating at BWR-6 core average rod powers. The second transient simulated a generator load rejection without steam bypass with fuel rods operating at above core average powers. The last two transients were performed at higher powers than safety analysis predicts to be possible in commercial reactors to be defined failure threshold margins. The test rods did not fail and were not damaged during any of the four transients. (author)

A data processing program for transient sodium boiling and fuel failure propagation tests, (2)

International Nuclear Information System (INIS)

Hasebe, Takeshi; Isozaki, Tadashi; Satoh, Akihiro; Yamaguchi, Katsuhisa; Haga, Kazuo.

1983-01-01

Transient Sodium Boiling Tests and Fuel Failure Propagation Tests are being conducted with the out-of-pile test facility, SIENA, in the Core Safety Section of O-arai Engineering Center. The experimental data are recorded using a digital data acquisition system controlled by a HP-1000E computer. The SICILIAN (Speedy Illustration Code for Inspection Line Anomaly) code was developed to obtain quick graphic outputs of data recorded in the magnetic tapes. The program is written in BASIC and Assembler languages and uses a data processing system composed of a desktop computer HP 9845B, a magnetic tape system, a magnetic disc and an eightcolor plotter. The SICILIAN code enables us to get graphic outputs soon after a run. These outputs are very helpful to inspect anomaly in the instrument circuit and to check the experimental conditions of coming runs. (author)

A physically transient form of silicon electronics.

Science.gov (United States)

Hwang, Suk-Won; Tao, Hu; Kim, Dae-Hyeong; Cheng, Huanyu; Song, Jun-Kyul; Rill, Elliott; Brenckle, Mark A; Panilaitis, Bruce; Won, Sang Min; Kim, Yun-Soung; Song, Young Min; Yu, Ki Jun; Ameen, Abid; Li, Rui; Su, Yewang; Yang, Miaomiao; Kaplan, David L; Zakin, Mitchell R; Slepian, Marvin J; Huang, Yonggang; Omenetto, Fiorenzo G; Rogers, John A

2012-09-28

A remarkable feature of modern silicon electronics is its ability to remain physically invariant, almost indefinitely for practical purposes. Although this characteristic is a hallmark of applications of integrated circuits that exist today, there might be opportunities for systems that offer the opposite behavior, such as implantable devices that function for medically useful time frames but then completely disappear via resorption by the body. We report a set of materials, manufacturing schemes, device components, and theoretical design tools for a silicon-based complementary metal oxide semiconductor (CMOS) technology that has this type of transient behavior, together with integrated sensors, actuators, power supply systems, and wireless control strategies. An implantable transient device that acts as a programmable nonantibiotic bacteriocide provides a system-level example.

Compilation of Quality Assurance Documentation for Analyses Performed for the Resumption of Transient Testing Environmental Assessment

Energy Technology Data Exchange (ETDEWEB)

Schafer, Annette L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sondrup, A. Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2013-11-01

This is a companion document to the analyses performed in support of the environmental assessment for the Resumption of Transient Fuels and Materials Testing. It is provided to allow transparency of the supporting calculations. It provides computer code input and output. The basis for the calculations is documented separately in INL (2013) and is referenced, as appropriate. Spreadsheets used to manipulate the code output are not provided.

Instrument response during overpower transients at TREAT

International Nuclear Information System (INIS)

Meek, C.C.; Bauer, T.H.; Hill, D.J.; Froehle, P.H.; Klickman, A.E.; Tylka, J.P.; Doerner, R.C.; Wright, A.E.

1982-01-01

A program to empirically analyze data residuals or noise to determine instrument response that occurs during in-pile transient tests is out-lined. As an example, thermocouple response in the Mark III loop during a severe overpower transient in TREAT is studied both in frequency space and in real-time. Time intervals studied included both constant power and burst portions of the power transient. Thermocouple time constants were computed. Benefits and limitations of the method are discussed

Thermally induced dispersion mechanisms for aluminum-based plate-type fuels under rapid transient energy deposition

International Nuclear Information System (INIS)

Georgevich, V.; Taleyarkham, R.P.; Navarro-Valenti, S.; Kim, S.H.

1995-01-01

A thermally induced dispersion model was developed to analyze for dispersive potential and determine onset of fuel plate dispersion for Al-based research and test reactor fuels. Effect of rapid energy deposition in a fuel plate was simulated. Several data types for Al-based fuels tested in the Nuclear Safety Research Reactor in Japan and in the Transient Reactor Test in Idaho were reviewed. Analyses of experiments show that onset of fuel dispersion is linked to a sharp rise in predicted strain rate, which futher coincides with onset of Al vaporization. Analysis also shows that Al oxidation and exothermal chemical reaction between the fuel and Al can significantly affect the energy deposition characteristics, and therefore dispersion onset connected with Al vaporization, and affect onset of vaporization

Congestion management enhancing transient stability of power systems

International Nuclear Information System (INIS)

Esmaili, Masoud; Shayanfar, Heidar Ali; Amjady, Nima

2010-01-01

In a competitive electricity market, where market parties try to maximize their profits, it is necessary to keep an acceptable level of power system security to retain the continuity of electricity services to customers at a reasonable cost. Congestion in a power system is turned up due to network limits. After relieving congestion, the network may be operated with a reduced transient stability margin because of increasing the contribution of risky participants. In this paper, a novel congestion management method based on a new transient stability criterion is introduced. Using the sensitivity of corrected transient stability margin with respect to generations and demands, the proposed method so alleviates the congestion that the network can more retain its transient security compared with earlier methods. The proposed transient stability index is constructed considering the likelihood of credible faults. Indeed, market parties participate by their security-effective bids rather than raw bids. Results of testing the proposed method along with the earlier ones on the New-England test system elaborate the efficiency of the proposed method from the viewpoint of providing a better transient stability margin with a lower security cost. (author)

Effect of a Sulphate Transient on the EAC Crack Growth Behaviour of Low-Alloy RPV Steels under Simulated BWR Operating Conditions (CASTOC WP 3, PSI Test 1)

Energy Technology Data Exchange (ETDEWEB)

Ritter, S.; Seifert, H. P

2002-03-01

Within the CASTOC-project (5th EU FW programme), the environmentally-assisted crack (EAC) growth behaviour of low-alloy reactor pressure vessel (RPV) steels is experimentally investigated under simulated transient and steady-state boiling water reactor (BWR) power operation conditions by six European laboratories. Within WP 3 of this project, the Paul Scherrer Institut (PSI) investigates the effect of water chemistry transients on the EAC crack growth behaviour under periodical partial unloading (PPU) conditions. The present report is a summary of the first PSI test of WP 3 with a Na{sub 2}SO{sub 4} transient. In the first part of the report, the theoretical background on crack growth mechanisms, crack chemistry, mass transport and water chemistry transients as well as a brief literature survey on other water chemistry transient investigations is given. Furthermore, the experimental equipment and test procedure is presented, followed by a summary of the results of PSI test 1 of WP 3. Finally the results are discussed in detail and compared to literature data. In the first part of the experiment, an actively growing EAC crack was generated by PPU in oxygenated high-temperature, high-purity water (T = 288 {sup o}C, DO = 8 ppm, SO{sub 4}{sup 2-} < 0.6 ppb). Then a sulphate transient was applied. The duration ({approx} 300 h) and the amount of sulphate (SO{sub 4}{sup 2-} = 368 ppb) of the applied sulphate transient conservatively covered all sulphate transients, which might occur in BWR/normal water chemistry (NWC) practice. After the transient, outlet conductivity was lowered from ca. 1 {mu}S/cm to less than 0.15 {mu}S/cm within 2.6 h by a 'two-loop technique'. No accelerating effect of the sulphate transient on the EAC crack growth of both tested fracture mechanics specimens under highly oxidising BWR/NWC conditions was observed, making it impossible to deterrnine incubation or delay times. The EAC crack growth rates (CGR) before, during and after the

Experimental data report for transient flow calibration facility tests IIIA101, IIIA102, IIIA201, and IIIA202

International Nuclear Information System (INIS)

Wambach, J.L.

1980-01-01

Thermal-hydraulic response data are presented for the transient performance tests of an ECC pitot tube rake (IIIA201, IIIA202) and both an ECC pitot tube rake and modular drag disc-turbine transducer (DTT) rake (IIIA101, IIIA102). The tests were conducted in a system which provided full scale simulation of the pressure vessel and intact loop cold leg piping of the Loss of Fluid Test Facility (LOFT). A load cell system was used to provide a reference mass flow rate measurement

Transient left ventricular apical ballooning and exercise induced hypertension during treadmill exercise testing: is there a common hypersympathetic mechanism?

Directory of Open Access Journals (Sweden)

Oh Jae K

2008-07-01

Full Text Available Abstract Objective To describe two cases of Takotsubo like myocardial contractile pattern during exercise stress test secondary to hypertensive response. Background Treadmill exercise testing is known to cause sympathetic stimulation, leading to increased levels of catecholamine, resulting in alteration in vascular tone. Hypertensive response during exercise testing can cause abnormal consequences, resulting in false positive results. Cases We present the cases of two patients experiencing apical and basal akinesis during exercise stress echocardiography, in whom normal wall motion response was observed on subsequent pharmacologic stress testing. The first patient developed transient left ventricular (LV apical akinesis during exercise stress echocardiography. Due to high suspicion that this abnormality might be secondary to hypertensive response, pharmacologic stress testing was performed after three days, which was completely normal and showed no such wall motion abnormality. Qualitative assessment of myocardial perfusion using contrast was also performed, which showed good myocardial blood flow, indicating low probability for significant obstructive coronary artery disease. The second patient developed LV basal akinesis as a result of hypertensive response during exercise testing. Coronary angiogram was not performed in either patient due to low suspicion for coronary artery disease, and subsequently negative stress studies. Results Transient stress induced cardiomyopathy can develop secondary to hypertensive response during exercise stress testing. Conclusion These cases provide supporting evidence to the hyper-sympathetic theory of left ventricular ballooning syndrome.

HECTR [Hydrogen Event: Containment Transient Response] analyses of the Nevada Test Site (NTS) premixed combustion experiments

International Nuclear Information System (INIS)

Wong, C.C.

1988-11-01

The HECTR (Hydrogen Event: Containment Transient Response) computer code has been developed at Sandia National Laboratories to predict the transient pressure and temperature responses within reactor containments for hypothetical accidents involving the transport and combustion of hydrogen. Although HECTR was designed primarily to investigate these phenomena in LWRs, it may also be used to analyze hydrogen transport and combustion experiments as well. It is in this manner that HECTR is assessed and empirical correlations, such as the combustion completeness and flame speed correlations for the hydrogen combustion model, if necessary, are upgraded. In this report, we present HECTR analyses of the large-scale premixed hydrogen combustion experiments at the Nevada Test Site (NTS) and comparison with the test results. The existing correlations in HECTR version 1.0, under certain conditions, have difficulty in predicting accurately the combustion completeness and burn time for the NTS experiments. By combining the combustion data obtained from the NTS experiments with other experimental data (FITS, VGES, ACUREX, and Whiteshell), a set of new and better combustion correlations was generated. HECTR prediction of the containment responses, using a single-compartment model and EPRI-provided combustion completeness and burn time, compares reasonably well against the test results. However, HECTR prediction of the containment responses using a multicompartment model does not compare well with the test results. This discrepancy shows the deficiency of the homogeneous burning model used in HECTR. To overcome this deficiency, a flame propagation model is highly recommended. 16 refs., 84 figs., 5 tabs

Methods study of homogeneity and stability test from cerium oxide CRM candidate

International Nuclear Information System (INIS)

Samin; Susanna TS

2016-01-01

The methods study of homogeneity and stability test from cerium oxide CRM candidate has been studied based on ISO 13258 and KAN DP. 01. 34. The purpose of this study was to select the test method homogeneity and stability tough on making CRM cerium oxide. Prepared 10 sub samples of cerium oxide randomly selected types of analytes which represent two compounds, namely CeO_2 and La_2O_3. At 10 sub sample is analyzed CeO_2 and La_2O_3 contents in duplicate with the same analytical methods, by the same analyst, and in the same laboratory. Data analysis results calculated statistically based on ISO 13528 and KAN DP.01.34. According to ISO 13528 Cerium Oxide samples said to be homogeneous if Ss ≤ 0.3 σ and is stable if | Xr – Yr | ≤ 0.3 σ. In this study, the data of homogeneity test obtained CeO_2 is Ss = 2.073 x 10-4 smaller than 0.3 σ (0.5476) and the stability test obtained | Xr - Yr | = 0.225 and the price is < 0.3 σ. Whereas for La_2O_3, the price for homogeneity test obtained Ss = 1.649 x 10-4 smaller than 0.3 σ (0.4865) and test the stability of the price obtained | Xr - Yr | = 0.2185 where the price is < 0.3 σ. Compared with the method from KAN, a sample of cerium oxide has also been homogenized for Fcalc < Ftable and stable, because | Xi - Xhm | < 0.3 x n IQR. Provided that the results of the evaluation homogeneity and stability test from CeO_2 CRM candidate test data were processed using statistical methods ISO 13528 is not significantly different with statistical methods from KAN DP.01.34, which together meet the requirements of a homogeneous and stable. So the test method homogeneity and stability test based on ISO 13528 can be used to make CRM cerium oxide. (author)

Near interface traps in SiO{sub 2}/4H-SiC metal-oxide-semiconductor field effect transistors monitored by temperature dependent gate current transient measurements

Energy Technology Data Exchange (ETDEWEB)

Fiorenza, Patrick; La Magna, Antonino; Vivona, Marilena; Roccaforte, Fabrizio [Consiglio Nazionale delle Ricerche-Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, Zona Industriale 95121 Catania (Italy)

2016-07-04

This letter reports on the impact of gate oxide trapping states on the conduction mechanisms in SiO{sub 2}/4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs). The phenomena were studied by gate current transient measurements, performed on n-channel MOSFETs operated in “gate-controlled-diode” configuration. The measurements revealed an anomalous non-steady conduction under negative bias (V{sub G} > |20 V|) through the SiO{sub 2}/4H-SiC interface. The phenomenon was explained by the coexistence of a electron variable range hopping and a hole Fowler-Nordheim (FN) tunnelling. A semi-empirical modified FN model with a time-depended electric field is used to estimate the near interface traps in the gate oxide (N{sub trap} ∼ 2 × 10{sup 11} cm{sup −2}).

Test plan for long-term, low-temperature oxidation of spent fuel, Series 1

International Nuclear Information System (INIS)

Einziger, R.E.

1986-06-01

Preliminary studies indicated the need for more spent fuel oxidation data in order to determine the probable behavior of spent fuel in a tuff repository. Long-term, low-temperature testing was recommended in a comprehensive technical approach to: (1) confirm the findings of the short-term thermogravimetric analyses scoping experiments; (2) evaluate the effects of variables such as burnup, atmospheric moisture and fuel type on the oxidation rate; and (3) extend the oxidation data base ot representative repository temperatures and better define the temperature dependence of the operative oxidation mechanisms. This document presents the Series 1 test plan to study, on a large number of samples, the effects of atmospheric moisture and temperature on oxidation rate and phase formation. Tests will run for up to two years, use characterized fragmented, and pulverized fuel samples, cover a temperature range of 110 0 C to 175 0 C and be conducted with an atmospheric moisture content rangeing from 0 C to approx. 80 0 C dew point. After testing, the samples will be examined and made available for leaching testing

FAST: a combined NOC and transient fuel performance model using a commercial FEM environment

Energy Technology Data Exchange (ETDEWEB)

Prudil, A.; Bell, J.; Oussoren, A.; Chan, P. [Royal Military College of Canada, Kingston, ON (Canada); Lewis, B. [Univ. of Ontario Inst. of Tech., Oshawa, ON (Canada)

2014-07-01

The Fuel And Sheath modelling Tool (FAST) is a combined normal operating conditions (NOC) and transient fuel performance code developed on the COMSOL Multiphysics finite-element platform. The FAST code has demonstrated excellent performance in proof of concept validation tests against experimental data and comparison to the ELESIM, ELESTRES and ELOCA fuel performance codes. In this paper we discuss ongoing efforts to expand the capabilities of the code to include multiple pellet geometries, model stress-corrosion cracking phenomena and modelling of advanced fuels composed of mixed oxides of thorium, uranium, and plutonium for the Canadian Supercritical Water Reactor (SCWR). (author)

Aging Depth Test of Rubber Blocks by Accelerated Thermal Oxidation Test

International Nuclear Information System (INIS)

Park, Junhee; Choun, Young-Sun; Kim, Min Kyu

2015-01-01

In this study, the accelerated thermal oxidation tests of rubber block were performed to investigate the aging depth of rubber bearing. From the tests, it was found the critical aging depth in rubber block. Also the property variation of rubber was investigated along the depth. The deterioration pattern from the aging depth tests was found from surface to inside and the critical aging depth was to be about 10 mm. The analytical model for rubber bearing with aging can be developed based on the relationship between the property variation and aging depth investigated from this study. The mechanical properties of rubber bearings were changed with time. Because the aging effect of rubber material was generally higher than that of other structure materials it is needed that the aging properties of seismically isolators should be evaluated to ensure the safety of seismically isolated nuclear power plants (NPPs) over the lifetime. NRC and ASCE required the tests of seismically isolators for investigating the aging properties. JNES also required the seismic response analysis for the seismically isolated NPPs when the properties of seismically isolators were extremely changed. If the aging properties of seismically isolators such as rubber bearings are evaluated by analysis the analytical model of seismically isolators should be developed considering aging effect of rubber material. From the previous research, it was reported that the behavior of aged rubber material mainly affected by temperature and oxidation. The material properties between surface and inside can be different by the oxidation of rubber. Therefore, the aging depth should be investigated for exactly evaluating the seismic behavior of aged rubber bearing. The aging depth of rubber baring was not influenced by the size of seismically isolators but environment condition. Therefore, the detail analysis considering aging depth was not required for NPPs with large seismically isolators. But the seismic response

Nuclear reactors transients identification and classification system

International Nuclear Information System (INIS)

Bianchi, Paulo Henrique

2008-01-01

This work describes the study and test of a system capable to identify and classify transients in thermo-hydraulic systems, using a neural network technique of the self-organizing maps (SOM) type, with the objective of implanting it on the new generations of nuclear reactors. The technique developed in this work consists on the use of multiple networks to do the classification and identification of the transient states, being each network a specialist at one respective transient of the system, that compete with each other using the quantization error, that is a measure given by this type of neural network. This technique showed very promising characteristics that allow the development of new functionalities in future projects. One of these characteristics consists on the potential of each network, besides responding what transient is in course, could give additional information about that transient. (author)

Turbofan compressor dynamics during afterburner transients

Science.gov (United States)

Kurkov, A. P.

1976-01-01

The effects of afterburner light-off and shut-down transients on the compressor stability are investigated. The reported experimental results are based on detailed high response pressure and temperature measurements on the TF30-P-3 turbofan engine. The tests were performed in an altitude test chamber simulating high altitude engine operation. It is shown that during both types of transients, flow breaks down in the forward part of the fan bypass duct. At a sufficiently low engine inlet pressure this resulted in a compressor stall. Complete flow breakdown within the compressor was preceded by a rotating stall. At some locations in the compressor, rotating stall cells initially extended only through part of the blade span. For the shutdown transient the time between first and last detected occurrence of rotating stall is related to the flow Reynolds number. An attempt was made to deduce the number and speed of propagation of rotating stall cells.

Mitochondrial alterations and oxidative stress in an acute transient mouse model of muscle degeneration: implications for muscular dystrophy and related muscle pathologies.

Science.gov (United States)

Ramadasan-Nair, Renjini; Gayathri, Narayanappa; Mishra, Sudha; Sunitha, Balaraju; Mythri, Rajeswara Babu; Nalini, Atchayaram; Subbannayya, Yashwanth; Harsha, Hindalahalli Chandregowda; Kolthur-Seetharam, Ullas; Srinivas Bharath, Muchukunte Mukunda

2014-01-03

Muscular dystrophies (MDs) and inflammatory myopathies (IMs) are debilitating skeletal muscle disorders characterized by common pathological events including myodegeneration and inflammation. However, an experimental model representing both muscle pathologies and displaying most of the distinctive markers has not been characterized. We investigated the cardiotoxin (CTX)-mediated transient acute mouse model of muscle degeneration and compared the cardinal features with human MDs and IMs. The CTX model displayed degeneration, apoptosis, inflammation, loss of sarcolemmal complexes, sarcolemmal disruption, and ultrastructural changes characteristic of human MDs and IMs. Cell death caused by CTX involved calcium influx and mitochondrial damage both in murine C2C12 muscle cells and in mice. Mitochondrial proteomic analysis at the initial phase of degeneration in the model detected lowered expression of 80 mitochondrial proteins including subunits of respiratory complexes, ATP machinery, fatty acid metabolism, and Krebs cycle, which further decreased in expression during the peak degenerative phase. The mass spectrometry (MS) data were supported by enzyme assays, Western blot, and histochemistry. The CTX model also displayed markers of oxidative stress and a lowered glutathione reduced/oxidized ratio (GSH/GSSG) similar to MDs, human myopathies, and neurogenic atrophies. MS analysis identified 6 unique oxidized proteins from Duchenne muscular dystrophy samples (n = 6) (versus controls; n = 6), including two mitochondrial proteins. Interestingly, these mitochondrial proteins were down-regulated in the CTX model thereby linking oxidative stress and mitochondrial dysfunction. We conclude that mitochondrial alterations and oxidative damage significantly contribute to CTX-mediated muscle pathology with implications for human muscle diseases.

Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

Science.gov (United States)

Azizi, Mohammad Ali; Brouwer, Jacob

2017-10-01

A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

The DSNP simulation language and its application to liquid-metal fast breeder reactor transient analyses

International Nuclear Information System (INIS)

Saphier, D.; Madell, J.T.

1982-01-01

A new, special purpose block-oriented simulation language, the Dynamic Simulator for Nuclear Power Plants (DSNP), was used to perform a dynamic analysis of several conceptual design studies of liquid metal fast breeder reactors. The DSNP being a high level language enables the user to transform a power plant flow chart directly into a simulation program using a small number of DSNP statements. In addition to the language statements, the DSNP system has its own precompiler and an extensive library containing models of power plant components, algorithms of physical processes, material property functions, and various auxiliary functions. The comparative analysis covered oxide-fueled versus metal-fueled core designs and loop- versus pool-type reactors. The question of interest was the rate of change of the temperatures in the components in the upper plenum and the primary loop, in particular the reactor outlet nozzle and the intermediate heat exchanger inlet nozzle during different types of transients. From the simulations performed it can be concluded that metal-fueled cores will have much faster temperature transients than oxide-fueled cores due mainly to the much higher thermal diffusivity of the metal fuel. The transients in the pool-type design (either with oxide fuel or metal fuel) will be much slower than in the loop-type design due to the large heat capacity of the sodium pool. The DSNP language was demonstrated to be well suited to perform many types of transient analysis in nuclear power plants

Cirrhosis Diagnosis and Liver Fibrosis Staging: Transient Elastometry Versus Cirrhosis Blood Test.

Science.gov (United States)

Calès, Paul; Boursier, Jérôme; Oberti, Frédéric; Bardou, Derek; Zarski, Jean-Pierre; de Lédinghen, Victor

2015-07-01

Elastometry is more accurate than blood tests for cirrhosis diagnosis. However, blood tests were developed for significant fibrosis, with the exception of CirrhoMeter developed for cirrhosis. We compared the performance of Fibroscan and CirrhoMeter, and classic binary cirrhosis diagnosis versus new fibrosis staging for cirrhosis diagnosis. The diagnostic population included 679 patients with hepatitis C and liver biopsy (Metavir staging and morphometry), Fibroscan, and CirrhoMeter. The prognostic population included 1110 patients with chronic liver disease and both tests. Binary diagnosis: AUROCs for cirrhosis were: Fibroscan: 0.905; CirrhoMeter: 0.857; and P=0.041. Accuracy (Youden cutoff) was: Fibroscan: 85.4%; CirrhoMeter: 79.2%; and PFibrosis classification provided 6 classes (F0/1, F1/2, F2±1, F3±1, F3/4, and F4). Accuracy was: Fibroscan: 88.2%; CirrhoMeter: 88.8%; and P=0.77. A simplified fibrosis classification comprised 3 categories: discrete (F1±1), moderate (F2±1), and severe (F3/4) fibrosis. Using this simplified classification, CirrhoMeter predicted survival better than Fibroscan (respectively, χ=37.9 and 19.7 by log-rank test), but both predicted it well (Ptest). Comparison: binary diagnosis versus fibrosis classification, respectively, overall accuracy: CirrhoMeter: 79.2% versus 88.8% (PFibrosis classification should be preferred over binary diagnosis. A cirrhosis-specific blood test markedly attenuates the accuracy deficit for cirrhosis diagnosis of usual blood tests versus transient elastometry, and may offer better prognostication.

Transient dynamic and modeling parameter sensitivity analysis of 1D solid oxide fuel cell model

International Nuclear Information System (INIS)

Huangfu, Yigeng; Gao, Fei; Abbas-Turki, Abdeljalil; Bouquain, David; Miraoui, Abdellatif

2013-01-01

Highlights: • A multiphysics, 1D, dynamic SOFC model is developed. • The presented model is validated experimentally in eight different operating conditions. • Electrochemical and thermal dynamic transient time expressions are given in explicit forms. • Parameter sensitivity is discussed for different semi-empirical parameters in the model. - Abstract: In this paper, a multiphysics solid oxide fuel cell (SOFC) dynamic model is developed by using a one dimensional (1D) modeling approach. The dynamic effects of double layer capacitance on the electrochemical domain and the dynamic effect of thermal capacity on thermal domain are thoroughly considered. The 1D approach allows the model to predict the non-uniform distributions of current density, gas pressure and temperature in SOFC during its operation. The developed model has been experimentally validated, under different conditions of temperature and gas pressure. Based on the proposed model, the explicit time constant expressions for different dynamic phenomena in SOFC have been given and discussed in detail. A parameters sensitivity study has also been performed and discussed by using statistical Multi Parameter Sensitivity Analysis (MPSA) method, in order to investigate the impact of parameters on the modeling accuracy

Twenty-five years of transient counting experience in French PWR units

Energy Technology Data Exchange (ETDEWEB)

Barthelet, B. [Electricite de France (EDF DPN), 93 - Saint-Denis (France); Savoldelli, D.; Fritz, R. [Electricite de France (EDF DPN), 93 - Noisy le Grand (France)

2001-07-01

For nearly twenty five years, EDF has been checking that the actual operating transients are neither more severe nor more numerous than the design basis transients. This activity of transient cycle counting and bookkeeping has enabled EDF to own a database of more than 800 reactor.years for the PWR units. The current method of transient cycle counting is presented. In the paper, we will point out the main results of transient cycle counting and lessons learned. In general, the frequencies of transients are lower than the design frequencies. In few cases, they are higher, such as the transient frequencies of the RCS lines connected to auxiliary systems often due to operating procedures or particular periodic testing. Few periodic tests were not taken into account in the design basis transient file ; they have been detected thanks to the transient cycle counting. In the last 1980's, we achieved the first updating of the design basis transient file for the PWR 900 MWe series. In the early 1990's, we updated the design basis transient file of the PWR 1300 MWe series. In fact, since design and start-up, the operating conditions have been modified (fuel cycle with stretch-out, modification of the hot leg and cold leg temperatures for the PWR 1300 MWe,...). This was the cause of many unclassified transients. In the new design basis transient file, we have created new transients and increased the frequencies of some of them. This has enabled to consider the updated design basis transient file more representative of actual operating transients. For some years, we have increasingly associated the operators with the transient cycle counting concern. We noticed progress (decreased frequencies of most transients). (authors)

Twenty-five years of transient counting experience in French PWR units

International Nuclear Information System (INIS)

Barthelet, B.; Savoldelli, D.; Fritz, R.

2001-01-01

For nearly twenty five years, EDF has been checking that the actual operating transients are neither more severe nor more numerous than the design basis transients. This activity of transient cycle counting and bookkeeping has enabled EDF to own a database of more than 800 reactor.years for the PWR units. The current method of transient cycle counting is presented. In the paper, we will point out the main results of transient cycle counting and lessons learned. In general, the frequencies of transients are lower than the design frequencies. In few cases, they are higher, such as the transient frequencies of the RCS lines connected to auxiliary systems often due to operating procedures or particular periodic testing. Few periodic tests were not taken into account in the design basis transient file ; they have been detected thanks to the transient cycle counting. In the last 1980's, we achieved the first updating of the design basis transient file for the PWR 900 MWe series. In the early 1990's, we updated the design basis transient file of the PWR 1300 MWe series. In fact, since design and start-up, the operating conditions have been modified (fuel cycle with stretch-out, modification of the hot leg and cold leg temperatures for the PWR 1300 MWe,...). This was the cause of many unclassified transients. In the new design basis transient file, we have created new transients and increased the frequencies of some of them. This has enabled to consider the updated design basis transient file more representative of actual operating transients. For some years, we have increasingly associated the operators with the transient cycle counting concern. We noticed progress (decreased frequencies of most transients). (authors)

A field-scale test of in situ chemical oxidation through recirculation

International Nuclear Information System (INIS)

West, O.R.; Cline, S.R.; Holden, W.L.; Gardner, F.G.; Schlosser, B.M.; Siegrist, R.L.; Houk, T.C.

1998-01-01

In situ chemical oxidation is a developing class of remediation technologies in which organic contaminants are degraded in place by powerful oxidants. Successful implementation of this technology requires an effective means for dispersing the oxidant to contaminated regions in the subsurface. An oxidant delivery technique has been developed wherein the treatment solution is made by adding an oxidant to extracted groundwater. The oxidant-laden groundwater is then injected and recirculated into a contaminated aquifer through multiple horizontal and/or vertical wells. This technique, referred to as in situ chemical oxidation through recirculation (ISCOR), can be applied to saturated and hydraulically conductive formations and used with relatively stable oxidants such as potassium permanganate (KMnO 4 ). A field-scale test of ISCOR was conducted at a site (Portsmouth Gaseous Diffusion Plant) where groundwater in a 5-ft thick silty gravel aquifer is contaminated with trichloroethylene (TCE) at levels that indicate the presence of residual dense non-aqueous phase liquids (DNAPLs). The field test was implemented using a pair of parallel horizontal wells with 200-ft screened sections. For approximately one month, groundwater was extracted from one horizontal well, dosed with crystalline KMnO 4 , and re-injected into the other horizontal well 90 ft away. Post-treatment characterization showed that ISCOR was effective at removing TCE in the saturated region. Lateral and vertical heterogeneities within the treatment zone impacted the uniform delivery of the oxidant solution. However, TCE was not detected in groundwater samples collected from monitoring wells and soil samples from borings in locations where the oxidant had permeated

Electrical effects of transient neutron irradiation of silicon devices

International Nuclear Information System (INIS)

Hjalmarson, H.P.; Pease, R.L.; Van Ginhoven, R.M.; Schultz, P.A.; Modine, N.A.

2007-01-01

The key effects of combined transient neutron and ionizing radiation on silicon diodes and bipolar junctions transistors are described. The results show that interstitial defect reactions dominate the annealing effects in the first stage of annealing for certain devices. Furthermore, the results show that oxide trapped charge can influence the effects of bulk silicon displacement damage for particular devices

Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests

Energy Technology Data Exchange (ETDEWEB)

Braley, Jenifer C.; Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

2011-06-15

Scoping tests to evaluate the effects of agitation and pH adjustment on simulant sludge agglomeration and uranium metal oxidation at {approx}95 C were performed under Test Instructions(a,b) and as per sections 5.1 and 5.2 of this Test Plan prepared by AREVA. (c) The thermal testing occurred during the week of October 4-9, 2010. The results are reported here. For this testing, two uranium-containing simulant sludge types were evaluated: (1) a full uranium-containing K West (KW) container sludge simulant consisting of nine predominant sludge components; (2) a 50:50 uranium-mole basis mixture of uraninite [U(IV)] and metaschoepite [U(VI)]. This scoping study was conducted in support of the Sludge Treatment Project (STP) Phase 2 technology evaluation for the treatment and packaging of K-Basin sludge. The STP is managed by CH2M Hill Plateau Remediation Company (CHPRC) for the U.S. Department of Energy. Warm water ({approx}95 C) oxidation of sludge, followed by immobilization, has been proposed by AREVA and is one of the alternative flowsheets being considered to convert uranium metal to UO{sub 2} and eliminate H{sub 2} generation during final sludge disposition. Preliminary assessments of warm water oxidation have been conducted, and several issues have been identified that can best be evaluated through laboratory testing. The scoping evaluation documented here was specifically focused on the issue of the potential formation of high strength sludge agglomerates at the proposed 95 C process operating temperature. Prior hydrothermal tests conducted at 185 C produced significant physiochemical changes to genuine sludge, including the formation of monolithic concretions/agglomerates that exhibited shear strengths in excess of 100 kPa (Delegard et al. 2007).

Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests

International Nuclear Information System (INIS)

Braley, Jenifer C.; Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

2011-01-01

Scoping tests to evaluate the effects of agitation and pH adjustment on simulant sludge agglomeration and uranium metal oxidation at ∼95 C were performed under Test Instructions(a,b) and as per sections 5.1 and 5.2 of this Test Plan prepared by AREVA. (c) The thermal testing occurred during the week of October 4-9, 2010. The results are reported here. For this testing, two uranium-containing simulant sludge types were evaluated: (1) a full uranium-containing K West (KW) container sludge simulant consisting of nine predominant sludge components; (2) a 50:50 uranium-mole basis mixture of uraninite (U(IV)) and metaschoepite (U(VI)). This scoping study was conducted in support of the Sludge Treatment Project (STP) Phase 2 technology evaluation for the treatment and packaging of K-Basin sludge. The STP is managed by CH2M Hill Plateau Remediation Company (CHPRC) for the U.S. Department of Energy. Warm water (∼95 C) oxidation of sludge, followed by immobilization, has been proposed by AREVA and is one of the alternative flowsheets being considered to convert uranium metal to UO 2 and eliminate H 2 generation during final sludge disposition. Preliminary assessments of warm water oxidation have been conducted, and several issues have been identified that can best be evaluated through laboratory testing. The scoping evaluation documented here was specifically focused on the issue of the potential formation of high strength sludge agglomerates at the proposed 95 C process operating temperature. Prior hydrothermal tests conducted at 185 C produced significant physiochemical changes to genuine sludge, including the formation of monolithic concretions/agglomerates that exhibited shear strengths in excess of 100 kPa (Delegard et al. 2007).

Dynamic behaviour of mono bucket foundations subjected to combined transient loading

DEFF Research Database (Denmark)

Nielsen, Søren Dam; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

2015-01-01

This article presents the results from small scale testing, investigating the effect of transient combined loading of a bucketfoundation. The tests are performed inside a pressure tank at Aalborg University, Denmark. The bucket foundation was installed in dense water saturated sand and transient ...

Radiation-Induced Transient Effects in Near Infrared Focal Plane Arrays

Science.gov (United States)

Reed, Robert A.; Pickel, J.; Marshall, P.; Waczynski, A.; McMurray, R.; Gee, G.; Polidan, E.; Johnson, S.; McKeivey, M.; Ennico, K.;

Pressurizer and steam-generator behavior under PWR transient conditions

International Nuclear Information System (INIS)

Wahba, A.B.; Berta, V.T.; Pointner, W.

1983-01-01

Experiments have been conducted in the Loss-of-Fluid Test (LOFT) pressurized water reactor (PWR), at the Idaho National Engineering Laboratory, in which transient phenomena arising from accident events with and without reactor scram were studied. The main purpose of the LOFT facility is to provide data for the development of computer codes for PWR transient analyses. Significant thermal-hydraulic differences have been observed between the measured and calculated results for those transients in which the pressurizer and steam generator strongly influence the dominant transient phenomena. Pressurizer and steam generator phenomena that occurred during four specific PWR transients in the LOFT facility are discussed. Two transients were accompanied by pressurizer inflow and a reduction of the heat transfer in the steam generator to a very small value. The other two transients were accompanied by pressurizer outflow while the steam generator behavior was controlled

Cultural Resource Investigations for the Resumption of Transient Testing of Nuclear Fuels and Material at the Idaho National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Pace, Brenda R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Williams, Julie B. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2013-11-01

The U. S. Department of Energy (DOE) has a need to test nuclear fuels under conditions that subject them to short bursts of intense, high-power radiation called ‘transient testing’ in order to gain important information necessary for licensing new nuclear fuels for use in U.S. nuclear power plants, for developing information to help improve current nuclear power plant performance and sustainability, for improving the affordability of new generation reactors, for developing recyclable nuclear fuels, and for developing fuels that inhibit any repurposing into nuclear weapons. To meet this mission need, DOE is considering alternatives for re-use and modification of existing nuclear reactor facilities to support a renewed transient testing program. One alternative under consideration involves restarting the Transient Reactor Test (TREAT) reactor located at the Materials and Fuels Complex (MFC) on the Idaho National Laboratory (INL) site in southeastern Idaho. This report summarizes cultural resource investigations conducted by the INL Cultural Resource Management Office in 2013 to support environmental review of activities associated with restarting the TREAT reactor at the INL. These investigations were completed in order to identify and assess the significance of cultural resources within areas of potential effect associated with the proposed action and determine if the TREAT alternative would affect significant cultural resources or historic properties that are eligible for nomination to the National Register of Historic Places. No archaeological resources were identified in the direct area of potential effects for the project, but four of the buildings proposed for modifications are evaluated as historic properties, potentially eligible for nomination to the National Register of Historic Places. This includes the TREAT reactor (building #), control building (building #), guardhouse (building #), and warehouse (building #). The proposed re-use of these historic

Results of Testing the Relative Oxidizing Hazard of Wipes and KMI Zeolite

Energy Technology Data Exchange (ETDEWEB)

Ams, Bridget Elaine [Los Alamos National Laboratory

2017-05-09

This report includes the results from testing performed on the relative oxidizing hazard of a number of organic sorbing wipe materials, as well as KMI zeolite. These studies were undertaken to address a need by the Los Alamos National Laboratory (LANL) Hazardous Materials Management group, which requires a material that can sorb small spills in a glovebox without creating a disposal hazard due to the potential for oxidation reactions, as requested in Request for Testing of Wipes and Zeolite for Los Alamos National Laboratory Hazardous Materials Group (NPl-7) (NPl-7-17-002) and Request for Testing of Chamois Material for Los Alamos National Laboratory Hazardous Materials Group (NPl-7) (NPl-7-17-005). This set oftests is a continuation of previous testing described in Results from Preparation and Testing of Sorbents Mixed with (DWT-RPT-003), which provided data for the Waste Isolation Pilot Plant's Basis of Knowledge. The Basis of Knowledge establishes criteria for evaluating transuranic (TRU) waste that contains oxidizing chemicals.

Hot-Fire Test Results of Liquid Oxygen/RP-2 Multi-Element Oxidizer-Rich Preburners

Science.gov (United States)

Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.; Hulka, J. R.

2016-01-01

As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. To supply the oxidizer-rich combustion products to the main injector of the integrated test article, existing subscale preburner injectors from a previous NASA-funded oxidizer-rich staged combustion engine development program were utilized. For the integrated test article, existing and newly designed and fabricated inter-connecting hot gas duct hardware were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. However, before one of the preburners was used in the integrated test article, it was first hot-fire tested at length to prove it could provide the hot exhaust gas mean temperature, thermal uniformity and combustion stability necessary to perform in the integrated test article experiment. This paper presents results from hot-fire testing of several preburner injectors in a representative combustion chamber with a sonic throat. Hydraulic, combustion performance, exhaust gas thermal uniformity, and combustion stability data are presented. Results from combustion stability modeling of these test results are described in a companion paper at this JANNAF conference, while hot-fire test results of the preburner injector in the integrated test article are described in another companion paper.

Oxidative and antioxidative status in the testes of rats with acute epididymitis.

Science.gov (United States)

Kaya, Mete; Boleken, Mehmet Emin; Zeyrek, Fadile; Ozardali, Ilyas; Kanmaz, Turan; Erel, Ozcan; Yücesan, Selçuk

2006-01-01

Epididymitis is an inflammation or infection of the epididymis, a convoluted duct that lies on the posterior surface of the testicle. Oxidative stress due to excessive production of reactive oxygen species in epididymitis, impaired antioxidant defense mechanisms, or both, precipitates a range of pathologies that are currently believed to negatively affect the male reproductive function. How oxidative stress affects the testes is still unknown. We aimed to investigate the oxidative and antioxidative status of testes of rats with unilateral acute Escherichia coli epididymitis. The study included 36 male Wistar albino rats which were divided into three groups. In the epididymitis group (n = 12), an E. coli suspension was injected into the right ductus deferens of rats, and the same amount of saline was injected in the saline groups (n = 12). No surgery was performed in the control group (n = 12) for baseline values. Rats were sacrificed after 24 h and the epididymis and testes removed. The infection was confirmed by histopathologic evaluation and microbiological tests. The oxidative status of testes was evaluated by measuring myeloperoxidase (MPO) activity, and antioxidative status was evaluated by measuring total antioxidant response (TAR) and total antioxidant capacity levels (TAC). MPO activity in both the ipsilateral and contralateral testes of the epididymitis group was significantly higher than those of the saline and control groups (p antioxidants. 2006 S. Karger AG, Basel.

Investigation of the high temperature steam oxidation of Zircaloy 4 cladding tubes

International Nuclear Information System (INIS)

Leistikow, S.; Berg, H. v.; Kraft, R.; Pott, E.; Schanz, G.

1979-01-01

Also for the ORNL Zircaloy 4 cladding material, an intermediate decrease of the proportion of the ZrO 2 /α-phase layer was found, followed by an drastic increase when the breakaway of the ZrO 2 -scale occurred. Other reasons for small divergencies were evaluated, for instance temperature and time measurements, metallographic evaluation of layer thicknesses, consequences of one-sided (ORNL) and double-sided (KfK) oxidation. The so-called anomalous effect of steam oxidation during temperature transients was reproduced qualitatively and-in case that a reduced gain of oxygen was observed-explained by the predominant existence of the monoclinic oxide phase. The creep-rupture tests below 800 0 C showed a moderate prolongation of time-to-rupture when the tests were performed in steam (or after preoxidation in steam) instead of argon. Also slightly reduced maximum circumferential strain could be measured. (orig./RW) [de

Comparison between zircaloy oxidation in steam and air surroundings

International Nuclear Information System (INIS)

Shawkat, M.E.; Hasaneln, H.; Ali, M.; Parlatan, Y.; Albasha, H.

2013-01-01

The available experimental data for Zircaloy oxidation in air were reviewed. The behavior of the oxidation kinetics at different temperature ranges was described. It was shown that maintaining the oxidation kinetics within the oxide pre-breakaway region can prevent elevated sheath temperatures due to the oxidation process during postulated accidents. The available correlations to model the oxidation kinetics for pre-breakaway region were reviewed and assessed. Zircaloy-air oxidation correlation based on Leistikow-Berg data was determined to be the most suitable correlation to model pre-breakaway kinetics and it was compared to Urbanic-Heidrick correlation which is widely used for Zircaloy oxidation in steam environment. The results showed that the energy release due to the Zircaloy-steam oxidation bounds the energy released due to Zircaloy-air oxidation up to a sheath temperature referred as the “crossover temperature”. Below this temperature, the impact of Zircaloy-air oxidation on fuel sheath temperature transient can be predicted conservatively using the Urbanic-Heidrick steam correlation. The crossover temperature was calculated for isothermal sheath heating as well as transient sheath heat-up assuming three linear heating rates of 0.6, 1.0, and 1.3 K/s. (author)

Boiling and burnout phenomena under transient heat input, 1

International Nuclear Information System (INIS)

Aoki, Shigebumi; Kozawa, Yoshiyuki; Iwasaki, Hideaki.

1976-01-01

In order to simulate the thermo-hydrodynamic conditions at reactor power excursions, a test piece was placed in a forced convective channel and heated with exponential power inputs. The boiling heat transfer and the burnout heat flux under the transient heat input were measured, and pressure and water temperature changes in the test section were recorded at the same time. Following experimental results were obtained; (1) Transient boiling heat transfer characteristics at high heat flux stayed on the stationary nucleate boiling curve of each flow condition, or extrapolated line of the curves. (2) Transient burnout heat flux increased remarkably with decreasing heating-time-constant, when the flow rate was lower and the subcooling was higher. (3) Transient burnout phenomena were expressed with the relation of (q sub(max) - q sub(sBO)) tau = constant at several flow conditions. This relation was derived from the stationary burnout mechanism of pool boiling. (auth.)

Analysis of the FFTF primary pipe rupture transients

International Nuclear Information System (INIS)

Perkins, K.R.; Bari, R.A.; Chen, L.C.; Albright, D.C.

1979-01-01

The response of the Fast Flux Test Facility (FFTF) to hypothetical ruptures of the high pressure primary piping has been analyzed using two LMFBR plant systems codes, namely IANUS and DEMO. Comparisons of the average channel temperatures predicted by the two codes show good agreement for identical transients. However, the hot channel temperatures predicted by DEMO are about 60K higher than the corresponding IANUS predictions for severe transients. This difference is attributed to the dynamic hot channel factors employed in DEMO which discount the thermal inertia of the duct walls for rapid transients. DEMO also predicts more severe transients for hot-leg ruptures in FFTF than previously reported analyses for the CRBR

A new transiently chaotic flow with ellipsoid equilibria

Science.gov (United States)

Panahi, Shirin; Aram, Zainab; Jafari, Sajad; Pham, Viet-Thanh; Volos, Christos; Rajagopal, Karthikeyan

2018-03-01

In this article, a simple autonomous transiently chaotic flow with cubic nonlinearities is proposed. This system represents some unusual features such as having a surface of equilibria. We shall describe some dynamical properties and behaviours of this system in terms of eigenvalue structures, bifurcation diagrams, time series, and phase portraits. Various behaviours of this system such as periodic and transiently chaotic dynamics can be shown by setting special parameters in proper values. Our system belongs to a newly introduced category of transiently chaotic systems: systems with hidden attractors. Transiently chaotic behaviour of our proposed system has been implemented and tested by the OrCAD-PSpise software. We have found a proper qualitative similarity between circuit and simulation results.

RELAP5 capabilities in thermal-hydraulic prediction of SBWR containment behaviour: PANDA steady state and transient tests evaluation

International Nuclear Information System (INIS)

Faluomi, V.; Aksan, S.N.

2000-01-01

This paper summarizes the results of the qualification activity of RELAP5/Mod3.2 code performed using PANDA steady state and integral test experimental data. The steady state tests evaluate the PCC performances in removing decay heat power in presence and in absence of non-condensable gases, while the considered integral test (M3) simulates the transient following a break in the main steam line of the SBWR, using, as nominal initial conditions, those calculated for the SBWR under SSAR assumptions at one hour into the LOCA. The results obtained simulating both types of tests show a rather good and robust overall code behavior both in the simulation of steady state test and in the representation of the integral test considered: most of the main experimental results (WW/DW pressures, PCC heat exchange) were well represented by the code. The different studies performed indicated that: Different models of PCC pool lead a different trend of system pressure, and sometimes to an opening of vacuum breaker valves, that does not occur in the transient; The code underestimate the heat exchanged between PCC pool and tubes: n the considered test the system pressure is slightly overestimated (maximum 2% more than the experimental value). This fact is also proved by the differences in the temperature of the condensing mixture in the PCC, quite large in all the performed studies; The treatment of the non condensable gases, as implemented in the code, lead some errors in the calculation of the heat transfer coefficient in the PCC components and generally slow down the overall calculation. In general terms, the RELAP5/Mod3.2 was found to be suitable to represent the SBWR containment behavior under the conditions specified in the experimental side. (author)

Positive patch test reactions to oxidized limonene: exposure and relevance.

Science.gov (United States)

Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus; Johansen, Jeanne D; Garcia-Bravo, Begoña; Gimenez Arnau, Ana; Goh, Chee-Leok; Nixon, Rosemary; White, Ian R

2014-11-01

R-Limonene is a common fragrance terpene found in domestic and industrial products. R-Limonene autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% (range 2.3-12.1%) of 2900 patients showed a positive patch test reaction to oxidized R-limonene. To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis. Oxidized R-limonene 3.0% (containing limonene hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed. Overall, exposure to products containing limonene was found and assessed as being probably relevant for the patients' dermatitis in 36% of the limonene-allergic patients. In Barcelona and Copenhagen, > 70% of the patients were judged to have had an exposure to limonene assessed as relevant. Oxidized R-limonene is a common fragrance allergen, and limonene was frequently found in the labelling on the patients' products, and assessed as relevant for the patients' dermatitis. A large number of domestic and occupational sources for contact with R-limonene were identified. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Model for transient creep of southeastern New Mexico rock salt

International Nuclear Information System (INIS)

Herrmann, W.; Wawersik, W.R.; Lauson, H.S.

1980-11-01

In a previous analysis, existing experimental data pertaining to creep tests on rock salt from the Salado formation of S.E. New Mexico were fitted to an exponential transient creep law. While very early time portions of creep strain histories were not fitted very well for tests at low temperatures and stresses, initial creep rates in particular generally being underestimated, the exponential creep law has the property that the transient creep strain approaches a finite limit with time, and is therefore desirable from a creep modelling point of view. In this report, an analysis of transient creep is made. It is found that exponential transient creep can be related to steady-state creep through a universal creep curve. The resultant description is convenient for creep analyses where very early time behavior is not important

Transient feedback from fuel motion in metal IFR [Integral Fast Reactor] fuel

International Nuclear Information System (INIS)

Rhodes, E.A.; Stanford, G.S.; Regis, J.P.; Bauer, T.H.; Dickerman, C.E.

1990-01-01

Results from hodoscope data analyses are presented for TREAT transient-overpower tests M5 through M7 with emphasis on transient feedback mechanisms, including prefailure expansion at the tops of the fuel pins, subsequent dispersive axial fuel motion, and losses in relative worth of the fuel pins during the tests. Tests M5 and M6 were the first TOP tests of margin to cladding branch and prefailure elongation of D9-clad ternary (U-Pu-Zr) IFR-type fuel. Test M7 extended these results to high-burnup fuel and also initiated transient testing of HT9-clad binary (U-Zr) FFTF-driver fuel. Results show significant prefailure negative reactivity feedback and strongly negative feedback from fuel driven to failure. 4 refs., 6 figs

Sulfur driven nucleation mode formation in diesel exhaust under transient driving conditions.

Science.gov (United States)

Karjalainen, Panu; Rönkkö, Topi; Pirjola, Liisa; Heikkilä, Juha; Happonen, Matti; Arnold, Frank; Rothe, Dieter; Bielaczyc, Piotr; Keskinen, Jorma

2014-02-18

Sulfur driven diesel exhaust nucleation particle formation processes were studied in an aerosol laboratory, on engine dynamometers, and on the road. All test engines were equipped with a combination of a diesel oxidation catalyst (DOC) and a partial diesel particulate filter (pDPF). At steady operating conditions, the formation of semivolatile nucleation particles directly depended on SO2 conversion in the catalyst. The nucleation particle emission was most significant after a rapid increase in engine load and exhaust gas temperature. Results indicate that the nucleation particle formation at transient driving conditions does not require compounds such as hydrocarbons or sulfated hydrocarbons, however, it cannot be explained only by the nucleation of sulfuric acid. A real-world exhaust study with a heavy duty diesel truck showed that the nucleation particle formation occurs even with ultralow sulfur diesel fuel, even at downhill driving conditions, and that nucleation particles can contribute 60% of total particle number emissions. In general, due to sulfur storage and release within the exhaust aftertreatment systems and transients in driving, emissions of nucleation particles can even be the dominant part of modern diesel vehicle exhaust particulate number emissions.

Transient Hypothyroidism after Radioiodine for Graves' Disease: Challenges in Interpreting Thyroid Function Tests.

Science.gov (United States)

Sheehan, Michael T; Doi, Suhail A R

2016-03-01

Graves' disease is the most common cause of hyperthyroidism and is often managed with radioactive iodine (RAI) therapy. With current dosing schemes, the vast majority of patients develop permanent post-RAI hypothyroidism and are placed on life-long levothyroxine therapy. This hypothyroidism typically occurs within the first 3 to 6 months after RAI therapy is administered. Indeed, patients are typically told to expect life-long thyroid hormone replacement therapy to be required within this timeframe and many providers expect this post-RAI hypothyroidism to be complete and permanent. There is, however, a small subset of patients in whom a transient post-RAI hypothyroidism develops which, initially, presents exactly as the typical permanent hypothyroidism. In some cases the transient hypothyroidism leads to a period of euthyroidism of variable duration eventually progressing to permanent hypothyroidism. In others, persistent hyperthyroidism requires a second dose of RAI. Failure to appreciate and recognize the possibility of transient post-RAI hypothyroidism can delay optimal and appropriate treatment of the patient. We herein describe five cases of transient post-RAI hypothyroidism which highlight this unusual sequence of events. Increased awareness of this possible outcome after RAI for Graves' disease will help in the timely management of patients. © 2016 Marshfield Clinic.

Transient Hypothyroidism after Radioiodine for Graves’ Disease: Challenges in Interpreting Thyroid Function Tests

Science.gov (United States)

Sheehan, Michael T.; Doi, Suhail A.R.

2016-01-01

Graves’ disease is the most common cause of hyperthyroidism and is often managed with radioactive iodine (RAI) therapy. With current dosing schemes, the vast majority of patients develop permanent post-RAI hypothyroidism and are placed on life-long levothyroxine therapy. This hypothyroidism typically occurs within the first 3 to 6 months after RAI therapy is administered. Indeed, patients are typically told to expect life-long thyroid hormone replacement therapy to be required within this timeframe and many providers expect this post-RAI hypothyroidism to be complete and permanent. There is, however, a small subset of patients in whom a transient post-RAI hypothyroidism develops which, initially, presents exactly as the typical permanent hypothyroidism. In some cases the transient hypothyroidism leads to a period of euthyroidism of variable duration eventually progressing to permanent hypothyroidism. In others, persistent hyperthyroidism requires a second dose of RAI. Failure to appreciate and recognize the possibility of transient post-RAI hypothyroidism can delay optimal and appropriate treatment of the patient. We herein describe five cases of transient post-RAI hypothyroidism which highlight this unusual sequence of events. Increased awareness of this possible outcome after RAI for Graves’ disease will help in the timely management of patients. PMID:26864507

Standard Test Method for Measuring Extreme Heat-Transfer Rates from High-Energy Environments Using a Transient, Null-Point Calorimeter

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This test method covers the measurement of the heat-transfer rate or the heat flux to the surface of a solid body (test sample) using the measured transient temperature rise of a thermocouple located at the null point of a calorimeter that is installed in the body and is configured to simulate a semi-infinite solid. By definition the null point is a unique position on the axial centerline of a disturbed body which experiences the same transient temperature history as that on the surface of a solid body in the absence of the physical disturbance (hole) for the same heat-flux input. 1.2 Null-point calorimeters have been used to measure high convective or radiant heat-transfer rates to bodies immersed in both flowing and static environments of air, nitrogen, carbon dioxide, helium, hydrogen, and mixtures of these and other gases. Flow velocities have ranged from zero (static) through subsonic to hypersonic, total flow enthalpies from 1.16 to greater than 4.65 × 101 MJ/kg (5 × 102 to greater than 2 × 104 ...

Mechanical response of FFTF reference and P1 cladding tubes under transient heating

International Nuclear Information System (INIS)

Youngahl, C.A.; Ariman, T.; Lepacek, B.E.

1977-01-01

Burst tests of Type 316 stainless steel cladding tube samples subjected to increasing temperature and relatively constant internal pressure were conducted to assist in the pretest analysis of the P1 experiment performed in the Sodium Loop Safety Facility. This paper reports and analyzes the burst test results and those of subsequent transient heating work. The use of a modified extensometer in obtaining mechanical response data for stainless steel in the high temperature range is illustrated, some of such data is provided, and the potential of further experiments and analysis is indicated. Tubing of the same design as Fast Flux Test Facility (FFTF) cladding (20% cold worked, 0.230 in. OD, 15 mil wall) was tested as-received and after annealing or electrolytic thinning. P1 tubing (38% cold worked, 0.230 in. OD, 10 mil wall) was tested before and after aging under conditions anticipated in the P1 reactor experiment. The P1 cladding was designed to simulate FFTF tubing that had experienced irradiation embrittlement and attack by cesium oxide and sodium impurities

Transient Ischemic Attack Caused by Iron Deficiency Anemia

Directory of Open Access Journals (Sweden)

Ufuk Emre

2006-02-01

Full Text Available Transient Ischemic Attack Caused by Iron Deficiency Anemia Transient ischemic attacks are episodes of transient focal ischemia involving the brain or brainstem. They are commonly two to thirty minutes in duration and lasting less than 24 hours. Anemia of iron deficiency isn’t frequently cause for transient ischemic attack. It has been reported as a risk factor for childhood ischemic strokes. In the iron deficiency anemia, T‹A may develop as result of hypercoagulable state and increased viscosity that is caused by anemic hypoxia that is result of reduce hemoglobine level, seconder thrombosis and microcytose As iron deficiency anemia has been reported so rarely in adult patients with transient ischemic attacks as a cause, we aimed to discuss the clinical and outcome features of two cases with iron deficiency anemia and transient ischemic attacks in this study. Materials and methods: Routine neurologic examination, biochemical screen, serological tests, vasculitic markers, thyroid function tests, vitamin B 12 level, cranial imaging, vertebral carotid doppler USG examination was conducted in the two patients. Anemia of iron deficiency was found as the only risk factor for TIA and the two patients were treated with replacement of iron and antiagregan therapy. Neurological examination revealed no abnormality through the two years of follow-up. The iron deficiency anemia may be cause of many neurologic problems such a irritability, lethargy, headache, development retardation except from T‹A. In the iron deficiency anemia, early diagnosis and treatment is important

Test laboratories for elementary cells of a solid oxide fuel cell (SOFC); Laboratoire d`essais de cellules elementaires d`une pile a combustible a oxyde solide (SOFC)

Energy Technology Data Exchange (ETDEWEB)

Guerin, F.

1998-01-01

The solid oxide furl (SOFC) cell could well be the fuel most suited to stationary applications. Its high working temperature allows it to high value heat which can be used to increase electrical output (by the addition of a gas turbine), or to produce steam for heating or an industrial process. test laboratory for electrochemical cells has been created to test elementary cells whose dimensions do not exceed 5 x 5 cm. The SOFC, consisting of a ceramic sheet, is maintained in an oven at around 900 deg. C. It can produce a maximum continuous current of 25 A at a voltage of 0.7 V on an electronic charge. Each test lasts at least 500 hours. Investigation of the prototype cells is intended to establish their electrochemical characteristics: activity, ionic and electronic conductivity, polarization curve stability behaviour under fast transient electronic regime. In parallel, modelings are performed and will be validated by these different tests results

Performance enhancement of microbial fuel cell by applying transient-state regulation

International Nuclear Information System (INIS)

Liang, Peng; Zhang, Changyong; Jiang, Yong; Bian, Yanhong; Zhang, Helan; Sun, Xueliang; Yang, Xufei; Zhang, Xiaoyuan; Huang, Xia

2017-01-01

Highlights: • MFC was operated with transient-state regulation to enhance its performance. • Effects of the TSR parameters on MFC performance were thoroughly investigated. • Long-term operation of MFC in TSR mode allowed 32.7% higher power production. • Anode capacitance helped reduce the MFC’s internal impedance in the TSR mode. - Abstract: A binder-free, pseudocapacitive anode was fabricated by coating reduced graphene oxide (rGO) and manganese oxide (MnO_2) nanoparticles on stainless steel fibre felt (SS). Microbial fuel cell (MFC) equipped with this novel anode yielded a maximum power density of 1045 mW m"−"2, 20 times higher than that of a similar MFC with a bare SS anode (46 mW m"−"2). Transient-state regulation (TSR) was implemented to further improve the MFC’s power generation. The optimal TSR duty cycle ranged from 67% to 95%, and the MFC’s power density increased with TSR frequency. A maximum power density output of 1238 mW m"−"2 was achieved at the TSR duty cycle of 75% and the frequency of 1 Hz, 18.4% greater than that obtained from the steady state operation. The TSR mode delivered better MFC performance especially when the external resistance was small. Long-term operation tests revealed that the current density and power density yielded in the TSR mode were on average 15.0% and 32.7% greater than those in the steady state mode, respectively. The TSR mode was believed to reduce the internal resistance of the MFC while enhance substrate mass transfer and electron transfer within the anode matrix, thereby improving the MFC performance.

Numerical modelling of methane oxidation efficiency and coupled water-gas-heat reactive transfer in a sloping landfill cover.

Science.gov (United States)

Feng, S; Ng, C W W; Leung, A K; Liu, H W

2017-10-01

Microbial aerobic methane oxidation in unsaturated landfill cover involves coupled water, gas and heat reactive transfer. The coupled process is complex and its influence on methane oxidation efficiency is not clear, especially in steep covers where spatial variations of water, gas and heat are significant. In this study, two-dimensional finite element numerical simulations were carried out to evaluate the performance of unsaturated sloping cover. The numerical model was calibrated using a set of flume model test data, and was then subsequently used for parametric study. A new method that considers transient changes of methane concentration during the estimation of the methane oxidation efficiency was proposed and compared against existing methods. It was found that a steeper cover had a lower oxidation efficiency due to enhanced downslope water flow, during which desaturation of soil promoted gas transport and hence landfill gas emission. This effect was magnified as the cover angle and landfill gas generation rate at the bottom of the cover increased. Assuming the steady-state methane concentration in a cover would result in a non-conservative overestimation of oxidation efficiency, especially when a steep cover was subjected to rainfall infiltration. By considering the transient methane concentration, the newly-modified method can give a more accurate oxidation efficiency. Copyright © 2017. Published by Elsevier Ltd.

Test CMOS/SOS RAM for transient radiation upset comparative research and failure analysis

International Nuclear Information System (INIS)

Nikiforov, A.Y.; Poljakov, I.V.

1995-01-01

The test Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) with eight types of memory cells was designed and tested at high dose rates with a flash X-ray machine and laser simulator. The memory cell (MC) design with additional transistors and RC-chain was found to be upset free up to 2 x 10 12 rad(Si)/s. An inversion effect was discovered in which almost 100% logic upset was observed in poorly protected memory cell arrays at very high dose rates

DETECTION OF FAST TRANSIENTS WITH RADIO INTERFEROMETRIC ARRAYS

International Nuclear Information System (INIS)

Bhat, N. D. R.; Chengalur, J. N.; Gupta, Y.; Prasad, J.; Roy, J.; Kudale, S. S.; Cox, P. J.; Bailes, M.; Burke-Spolaor, S.; Van Straten, W.

2013-01-01

Next-generation radio arrays, including the Square Kilometre Array (SKA) and its pathfinders, will open up new avenues for exciting transient science at radio wavelengths. Their innovative designs, comprising a large number of small elements, pose several challenges in digital processing and optimal observing strategies. The Giant Metre-wave Radio Telescope (GMRT) presents an excellent test-bed for developing and validating suitable observing modes and strategies for transient experiments with future arrays. Here we describe the first phase of the ongoing development of a transient detection system for GMRT that is planned to eventually function in a commensal mode with other observing programs. It capitalizes on the GMRT's interferometric and sub-array capabilities, and the versatility of a new software backend. We outline considerations in the plan and design of transient exploration programs with interferometric arrays, and describe a pilot survey that was undertaken to aid in the development of algorithms and associated analysis software. This survey was conducted at 325 and 610 MHz, and covered 360 deg 2 of the sky with short dwell times. It provides large volumes of real data that can be used to test the efficacies of various algorithms and observing strategies applicable for transient detection. We present examples that illustrate the methodologies of detecting short-duration transients, including the use of sub-arrays for higher resilience to spurious events of terrestrial origin, localization of candidate events via imaging, and the use of a phased array for improved signal detection and confirmation. In addition to demonstrating applications of interferometric arrays for fast transient exploration, our efforts mark important steps in the roadmap toward SKA-era science.

Detection of Fast Transients with Radio Interferometric Arrays

Science.gov (United States)

Bhat, N. D. R.; Chengalur, J. N.; Cox, P. J.; Gupta, Y.; Prasad, J.; Roy, J.; Bailes, M.; Burke-Spolaor, S.; Kudale, S. S.; van Straten, W.

2013-05-01

Next-generation radio arrays, including the Square Kilometre Array (SKA) and its pathfinders, will open up new avenues for exciting transient science at radio wavelengths. Their innovative designs, comprising a large number of small elements, pose several challenges in digital processing and optimal observing strategies. The Giant Metre-wave Radio Telescope (GMRT) presents an excellent test-bed for developing and validating suitable observing modes and strategies for transient experiments with future arrays. Here we describe the first phase of the ongoing development of a transient detection system for GMRT that is planned to eventually function in a commensal mode with other observing programs. It capitalizes on the GMRT's interferometric and sub-array capabilities, and the versatility of a new software backend. We outline considerations in the plan and design of transient exploration programs with interferometric arrays, and describe a pilot survey that was undertaken to aid in the development of algorithms and associated analysis software. This survey was conducted at 325 and 610 MHz, and covered 360 deg2 of the sky with short dwell times. It provides large volumes of real data that can be used to test the efficacies of various algorithms and observing strategies applicable for transient detection. We present examples that illustrate the methodologies of detecting short-duration transients, including the use of sub-arrays for higher resilience to spurious events of terrestrial origin, localization of candidate events via imaging, and the use of a phased array for improved signal detection and confirmation. In addition to demonstrating applications of interferometric arrays for fast transient exploration, our efforts mark important steps in the roadmap toward SKA-era science.

Modular time division multiplexer: Efficient simultaneous characterization of fast and slow transients in multiple samples

Science.gov (United States)

Kim, Stephan D.; Luo, Jiajun; Buchholz, D. Bruce; Chang, R. P. H.; Grayson, M.

2016-09-01

A modular time division multiplexer (MTDM) device is introduced to enable parallel measurement of multiple samples with both fast and slow decay transients spanning from millisecond to month-long time scales. This is achieved by dedicating a single high-speed measurement instrument for rapid data collection at the start of a transient, and by multiplexing a second low-speed measurement instrument for slow data collection of several samples in parallel for the later transients. The MTDM is a high-level design concept that can in principle measure an arbitrary number of samples, and the low cost implementation here allows up to 16 samples to be measured in parallel over several months, reducing the total ensemble measurement duration and equipment usage by as much as an order of magnitude without sacrificing fidelity. The MTDM was successfully demonstrated by simultaneously measuring the photoconductivity of three amorphous indium-gallium-zinc-oxide thin films with 20 ms data resolution for fast transients and an uninterrupted parallel run time of over 20 days. The MTDM has potential applications in many areas of research that manifest response times spanning many orders of magnitude, such as photovoltaics, rechargeable batteries, amorphous semiconductors such as silicon and amorphous indium-gallium-zinc-oxide.

CMOS/SOS RAM transient radiation upset and ''inversion'' effect investigation

International Nuclear Information System (INIS)

Nikiforov, A.Y.; Poljakov, I.V.

1996-01-01

The Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) transient upset and inversion effect were investigated with pulsed laser, pulsed voltage generator and low-intensity light simulators. It was found that the inversion of information occurs due to memory cell photocurrents simultaneously with the power supply voltage drop transfer to memory cells outputs

Aeroelastic Modeling of a Nozzle Startup Transient

Science.gov (United States)

Wang, Ten-See; Zhao, Xiang; Zhang, Sijun; Chen, Yen-Sen

2014-01-01

Lateral nozzle forces are known to cause severe structural damage to any new rocket engine in development during test. While three-dimensional, transient, turbulent, chemically reacting computational fluid dynamics methodology has been demonstrated to capture major side load physics with rigid nozzles, hot-fire tests often show nozzle structure deformation during major side load events, leading to structural damages if structural strengthening measures were not taken. The modeling picture is incomplete without the capability to address the two-way responses between the structure and fluid. The objective of this study is to develop a tightly coupled aeroelastic modeling algorithm by implementing the necessary structural dynamics component into an anchored computational fluid dynamics methodology. The computational fluid dynamics component is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, while the computational structural dynamics component is developed under the framework of modal analysis. Transient aeroelastic nozzle startup analyses at sea level were performed, and the computed transient nozzle fluid-structure interaction physics presented,

Change in geometrical parameters of WWER high burnup fuel rods under operational conditions and transient testing

International Nuclear Information System (INIS)

Kanashov, B.; Amosov, S.; Lyadov, G.; Markov, D.; Ovchinnikov, V; Polenok, V.; Smirnov, A.; Sukhikh, A.; Bek, E.; Yenin, A.; Novikov, V.

2001-01-01

The paper discusses changes in fuel rods geometric parameters as result of operation conditions and burnups. The degree of geometry variability of fuel rods, cladding and column is one of the most important characteristics affecting fuel serviceability. On the other hand, changes in fuel rod geometric parameters influence fuel temperature, fission gas release, fuel-to-cladding stress strained state as well as the degree of interaction with FA skeleton elements and skeleton rigidity. Change in fuel-to-cladding gap is measured using compression technique. The axial distribution of fuel-to-cladding gap demonstrates the largest decrease of the gap in the region 500 to 2000 mm from the bottom of the fuel rod (WWER-440) and in the region of 500 to 3000 mm for WWER-1000. The cladding material creep in WWER fuel rods together with the radiation growth results in fuel rod cladding elongation. A set of transient tests for spent WWER-440 and WWER-1000 fuel rods carried out in SSC RIAR during a period 1995-1999, with the aim to estimate the changes in geometric parameters of FRs. The estimation of changes in outer diameter of cladding and fuel column and fuel-to-cladding gap are performed in transient conditions (changes in linear power range of 180 to 400 W/cm) for both WWER-440 and WWER-1000. WWER-440 fuel rods having the same burnup and close fuel-cladding contact before testing are subjected to considerable hoop cladding strain in testing up to 300 W/cm. But the hoop strain does not grow due to the structural changes in fuel column and decrease in central hole diameter occurred when the power is higher

Final report for the H3 transient overpower failure threshold experiment

International Nuclear Information System (INIS)

Wright, A.E.; Rothman, A.B.; Stahl, D.; Agrawal, A.K.; Deitrich, L.W.; Chen, S.S.

1975-06-01

Test H3 was the first transient overpower failure-threshold experiment in TREAT to use irradiated fuel and to employ a TREAT transient shaped to produce sample-temperature distributions typical of steady state prior to the overpower excursion. A seven-pin assembly was tested within the Mark-II TREAT sodium loop. The experiment was performed successfully with satisfactory TREAT power transient and loop performance, and demonstrated the capability of intermediate-power EBR-II-irradiated fuel at low burnup (no central void) to withstand a mild overpower transient that terminated with fuel temperatures just short of the solidus without cladding strain. Calculated values of outlet coolant temperature and amount of molten fuel generally agree well with the test data. Posttest thermalhydraulic and mechanical analyses of the fuel pins are reported. Results of detailed nondestructive and destructive examinations of the preirradiated central pin and a fresh peripheral pin are presented. (U.S.)

Test of the Weak Equivalence Principle using LIGO observations of GW150914 and Fermi observations of GBM transient 150914

Directory of Open Access Journals (Sweden)

Molin Liu

2017-07-01

Full Text Available About 0.4 s after the Laser Interferometer Gravitational-Wave Observatory (LIGO detected a transient gravitational-wave (GW signal GW150914, the Fermi Gamma-ray Burst Monitor (GBM also found a weak electromagnetic transient (GBM transient 150914. Time and location coincidences favor a possible association between GW150904 and GBM transient 150914. Under this possible association, we adopt Fermi's electromagnetic (EM localization and derive constraints on possible violations of the Weak Equivalence Principle (WEP from the observations of two events. Our calculations are based on four comparisons: (1 The first is the comparison of the initial GWs detected at the two LIGO sites. From the different polarizations of these initial GWs, we obtain a limit on any difference in the parametrized post-Newtonian (PPN parameter Δγ≲10−10. (2 The second is a comparison of GWs and possible EM waves. Using a traditional super-Eddington accretion model for GBM transient 150914, we again obtain an upper limit Δγ≲10−10. Compared with previous results for photons and neutrinos, our limits are five orders of magnitude stronger than those from PeV neutrinos in blazar flares, and seven orders stronger than those from MeV neutrinos in SN1987A. (3 The third is a comparison of GWs with different frequencies in the range [35 Hz, 250 Hz]. (4 The fourth is a comparison of EM waves with different energies in the range [1 keV, 10 MeV]. These last two comparisons lead to an even stronger limit, Δγ≲10−8. Our results highlight the potential of multi-messenger signals exploiting different emission channels to strengthen existing tests of the WEP.

Hot-Fire Test Results of an Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged-Combustion Integrated Test Article

Science.gov (United States)

Hulka, J. R.; Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.

2016-01-01

As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. For the thrust chamber assembly of the test article, several configurations of new main injectors, using relatively conventional gas-centered swirl coaxial injector elements, were designed and fabricated. The design and fabrication of these main injectors are described in a companion paper at this JANNAF meeting. New ablative combustion chambers were fabricated based on hardware previously used at NASA for testing at similar size and pressure. An existing oxygen/RP-1 oxidizer-rich subscale preburner injector from a previous NASA-funded program, along with existing and new inter-connecting hot gas duct hardware, were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. Results from independent hot-fire tests of the preburner injector in a combustion chamber with a sonic throat are described in companion papers at this JANNAF conference. The resulting integrated test article - which includes the preburner, inter-connecting hot gas duct, main injector, and ablative combustion chamber - was assembled at Test Stand 116 at the East Test Area of the NASA Marshall Space Flight Center. The test article was well instrumented with static and dynamic pressure, temperature, and acceleration sensors to allow the collected data to be used for

Testing the utility of fluorescent proteins in Mimulus lewisii by an Agrobacterium-mediated transient assay.

Science.gov (United States)

Ding, Baoqing; Yuan, Yao-Wu

2016-04-01

The Agrobacterium -mediated transient expression assay by leaf infiltration in Mimulus lewisii is robust. Fluorescent proteins EGFP, EYFP and DsRed give bright fluorescence signals in the infiltrated tissue. Mimulus lewisii is an emerging developmental genetic model system. Recently developed genomic and genetic resources and a stable transformation protocol have greatly facilitated the identification and functional characterization of genes controlling the development of ecologically important floral traits using this species. To further expedite gene and protein function analyses in M. lewisii, we adopted and simplified the Agrobacterium-mediated transient gene expression method routinely used in tobacco plants. With the validated transient assay, we examined the performance of fluorescent proteins EGFP, EYFP and DsRed in M. lewisii. All three proteins gave bright fluorescence signals when transiently expressed in agroinfiltrated leaves. Furthermore, we demonstrated the utility of fluorescent proteins in M. lewisii by showing the nuclear localization of Reduced Carotenoid Pigmentation 1 (RCP1), a recently discovered R2R3-MYB transcription factor that regulates carotenoid pigmentation during flower development. Both the transient assay and the fluorescent proteins are valuable additions to the M. lewisii toolbox, making this emerging genetic and developmental model system even more powerful.

The transient radiation effects and hardness of programmed device

International Nuclear Information System (INIS)

Du Chuanhua; Xu Xianguo; Zhao Hailin

2014-01-01

A review and summary of research and development in the investigation of transient ionizing radiation effects in device and cirviut is presented. The transient ionizing radiation effects in two type of programmed device, that's 32 bit Microcontroller and antifuse FPGA, were studied. The expeiment test data indicate: The transient ionizing radiation effects of 32 bit Microcontroller manifested self-motion restart and Latchup, the Latchup threshold was 5 × 10"7 Gy (Si)/s. The transient ionizing radiation effects of FPGA was reset, no Latchup. The relationship of circuit effects to physical mechanisms was analized. A new method of hardness in circiut design was put forward. (authors)

Evaporative oxidation treatability test report

International Nuclear Information System (INIS)

1995-04-01

In 1992, Congress passed the Federal Facilities Compliance Act that requires the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs). In response to the need for mixed-waste treatment capacity where available off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed wastes with treatment options and develop a strategy for treatment of its mixed wastes. DOE-AL manages operations at nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment capacity to treat wastes at the sites where the wastes are generated. Treatment processes used for mixed waste not only must address the hazardous component (i.e., meet LDRs) but also must contain the radioactive component in a form that allows final disposal while protecting workers, the public, and the environment. On the basis of recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (GJPO) are evaporative oxidation, thermal desorption, and treated wastewater evaporation. Rust Geotech, the DOE-GJPO prime contractor, was assigned to design and fabricate mobile treatment units (MTUs) for these three technologies and to deliver the MTUs to selected DOE-AL sites. To conduct treatability tests at the GJPO, Rust leased a pilot-scale evaporative oxidation unit from the Clemson Technical Center (CTC), Anderson, South Carolina. The purpose of this report is to document the findings and results of tests performed using this equipment

Oxidation of aluminum alloy cladding for research and test reactor fuel

Science.gov (United States)

Kim, Yeon Soo; Hofman, G. L.; Robinson, A. B.; Snelgrove, J. L.; Hanan, N.

2008-08-01

The oxide thicknesses on aluminum alloy cladding were measured for the test plates from irradiation tests RERTR-6 and 7A in the ATR (advanced test reactor). The measured thicknesses were substantially lower than those of test plates with similar power from other reactors available in the literature. The main reason is believed to be due to the lower pH (pH 5.1-5.3) of the primary coolant water in the ATR than in the other reactors (pH 5.9-6.5) for which we have data. An empirical model for oxide film thickness predictions on aluminum alloy used as fuel cladding in the test reactors was developed as a function of irradiation time, temperature, surface heat flux, pH, and coolant flow rate. The applicable ranges of pH and coolant flow rates cover most research and test reactors. The predictions by the new model are in good agreement with the in-pile test data available in the literature as well as with the RERTR test data measured in the ATR.

Oxidation of aluminum alloy cladding for research and test reactor fuel

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeon Soo [Argonne National Laboratory, Nuclear Engineering, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: yskim@anl.gov; Hofman, G.L. [Argonne National Laboratory, Nuclear Engineering, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Snelgrove, J.L.; Hanan, N. [Argonne National Laboratory, Nuclear Engineering, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2008-08-31

The oxide thicknesses on aluminum alloy cladding were measured for the test plates from irradiation tests RERTR-6 and 7A in the ATR (advanced test reactor). The measured thicknesses were substantially lower than those of test plates with similar power from other reactors available in the literature. The main reason is believed to be due to the lower pH (pH 5.1-5.3) of the primary coolant water in the ATR than in the other reactors (pH 5.9-6.5) for which we have data. An empirical model for oxide film thickness predictions on aluminum alloy used as fuel cladding in the test reactors was developed as a function of irradiation time, temperature, surface heat flux, pH, and coolant flow rate. The applicable ranges of pH and coolant flow rates cover most research and test reactors. The predictions by the new model are in good agreement with the in-pile test data available in the literature as well as with the RERTR test data measured in the ATR.

Measuring the permeability of Eleana argillite from area 17, Nevada Test Site, using the transient method

International Nuclear Information System (INIS)

Lin, W.

1978-01-01

Using the transient method, we determine the permeability of high-quartz Eleana argillite from the Nevada Test Site as a function of effective pressure. By comparing calculated and observed pressure decay in the upstream reservoir, we have determined the permeability of intact and fractured specimens at effective pressures ranging from 1.0 to 24.0 MPa. Over this pressure range, Eleana argillite has a low permeability (10 -16 to 10 -19 cm 2 ) when intact and a higher permeability (10 -12 to 10 -17 cm 2 ) with one induced through-going fracture

On bacteria oxidizing enlargement scale test for uranium in-situ leaching at. 381 mine

International Nuclear Information System (INIS)

Hu Kaiguang; Wang Qingliang; Liu Yingjiu; Shi Wenge; Hu Shihe; Hu Yincai; Fang Qiu

1999-01-01

The results of enlarged scale test of bacteria as oxidizer for uranium in-situ leaching at No 381 mine showed that redox potential of the oxidized absorbed tailing water by bacteria is more than 510 mV, without any effects on after treatments by using bacteria as oxidizer and reduce oxidizer costs 70% compared with H 2 O 2 as oxidizer

An attempt for a unified description of mechanical testing on Zircaloy-4 cladding subjected to simulated LOCA transient

Directory of Open Access Journals (Sweden)

Desquines Jean

2016-01-01

Full Text Available During a Loss Of Coolant Accident (LOCA, an important safety requirement is that the reflooding of the core by the emergency core cooling system should not lead to a complete rupture of the fuel rods. Several types of mechanical tests are usually performed in the industry to determine the degree of cladding embrittlement, such as ring compression tests or four-point bending of rodlets. Many other tests can be found in the open literature. However, there is presently no real intrinsic understanding of the failure conditions in these tests which would allow translation of the results from one kind of mechanical testing to another. The present study is an attempt to provide a unified description of the failure not directly depending on the tested geometry. This effort aims at providing a better understanding of the link between several existing safety criteria relying on very different mechanical testing. To achieve this objective, the failure mechanisms of pre-oxidized and pre-hydrided cladding samples are characterized by comparing the behavior of two different mechanical tests: Axial Tensile (AT test and “C”-shaped Ring Compression Test (CCT. The failure of samples in both cases can be described by usual linear elastic fracture mechanics theory. Using interrupted mechanical tests, metallographic examinations have evidenced that a set of parallel cracks are nucleated at the inner and outer surface of the samples just before failure, crossing both the oxide layer and the oxygen rich alpha layer. The stress intensity factors for multiple crack geometry are determined for both AT and CCT samples using finite element calculations. After each mechanical test performed on high temperature steam oxidized samples, metallography is then used to individually determine the crack depth and crack spacing. Using these two important parameters and considering the applied load at fracture, the stress intensity factor at failure is derived for each tested

Lifetime improvement of sheathed thermocouples for use in high-temperature and thermal transient operations

International Nuclear Information System (INIS)

McCulloch, R.W.; Clift, J.H.

1982-01-01

Premature failure of small-diameter, magnesium-oxide-insulated sheathed thermocouples occurred when they were placed within nuclear fuel rod simulators (FRSs) to measure high temperatures and to follow severe thermal transients encountered during simulation of nuclear reactor accidents in Oak Ridge National Laboratory (ORNL) thermal-hydraulic test facilities. Investigation of thermally cycled thermocouples yielded three criteria for improvement of thermocouple lifetime: (1) reduction of oxygen impurities prior to and during their fabrication, (2) refinement of thermoelement grain size during their fabrication, and (3) elimination of prestrain prior to use above their recrystallization temperature. The first and third criteria were satisfied by improved techniques of thermocouple assembly and by a recovery anneal prior to thermocouple use

Supercritical water oxidation benchscale testing metallurgical analysis report

International Nuclear Information System (INIS)

Norby, B.C.

1993-02-01

This report describes metallurgical evaluation of witness wires from a series of tests using supercritical water oxidation (SCWO) to process cutting oil containing a simulated radionuclide. The goal of the tests was to evaluate the technology's ability to process a highly chlorinated waste representative of many mixed waste streams generated in the DOE complex. The testing was conducted with a bench-scale SCWO system developed by the Modell Development Corporation. Significant test objectives included process optimization for adequate destruction efficiency, tracking the radionuclide simulant and certain metals in the effluent streams, and assessment of reactor material degradation resulting from processing a highly chlorinated waste. The metallurgical evaluation described herein includes results of metallographic analysis and Scanning Electron Microscopy analysis of witness wires exposed to the SCWO environment for one test series

Chemical Characterization and Reactivity Testing of Fuel-Oxidizer Reaction Product (Test Report)

Science.gov (United States)

1996-01-01

The product of incomplete reaction of monomethylhydrazine (MMH) and nitrogen tetroxide (NTO) propellants, or fuel-oxidizer reaction product (FORP), has been hypothesized as a contributory cause of an anomaly which occurred in the chamber pressure (PC) transducer tube on the Reaction Control Subsystem (RCS) aft thruster 467 on flight STS-51. A small hole was found in the titanium-alloy PC tube at the first bend below the pressure transducer. It was surmised that the hole may have been caused by heat and pressure resulting from ignition of FORP. The NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) was requested to define the chemical characteristics of FORP, characterize its reactivity, and simulate the events in a controlled environment which may have lead to the Pc-tube failure. Samples of FORP were obtained from the gas-phase reaction of MMH with NTO under laboratory conditions, the pulsed firings of RCS thrusters with modified PC tubes using varied oxidizer or fuel lead times, and the nominal RCS thruster firings at WSTF and Kaiser-Marquardt. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), ion chromatography (IC), inductively coupled plasma (ICP) spectrometry, thermogravimetric analysis (TGA) coupled to FTIR (TGA/FTIR), and mechanical impact testing were used to qualitatively and quantitatively characterize the chemical, thermal, and ignition properties of FORP. These studies showed that the composition of FORP is variable but falls within a limited range of compositions that depends on the fuel loxidizer ratio at the time of formation, composition of the post-formation atmosphere (reducing or oxidizing), and reaction or postreaction temperature. A typical composition contains methylhydrazinium nitrate (MMHN), ammonium nitrate (AN), methylammonium nitrate (MAN), and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. The thermal decomposition

Modelling of Zircaloy-steam-oxidation under severe fuel damage conditions

International Nuclear Information System (INIS)

Malang, S.; Neitzel, H.J.

1983-01-01

Small break loss-of-coolant accidents and special transients in an LWR, in combination with loss of required safety systems, may lead to an uncovered core for an extended period of time. As a consequence, the cladding temperature could rise up to the melting point due to the decay heat, resulting in severely damaged fuel rods. During heat-up the claddings oxidize due to oxygen uptake from the steam atmosphere in the core. The modeling and assessment of the Zircaloy-steam oxidation under such conditions is important, mainly for two reasons: The oxidation of the cladding influences the temperature transients due to the exothermic heat of reaction; the amount of liquified fuel depends on the oxide layer thickness and the oxygen content of the remaining Zircaloy metal when the melting point is reached. (author)

PASP Plus Transient Pulse Monitor (TPM) - Data Analysis and Interpretation Report

National Research Council Canada - National Science Library

Adamo, Richard

1996-01-01

The Transient Pulse Monitor (TPM), part of the PASP Plus experiment aboard the APEX spacecraft, is designed to detect and characterize electromagnetic transient signals produced by electrostatic discharges on the solar array test modules...

Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

DEFF Research Database (Denmark)

Auer, C.; Lang, M.; Couturier, K.

2015-01-01

In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell/stack as......In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell...

Performance assessment of mass flow rate measurement capability in a large scale transient two-phase flow test system

International Nuclear Information System (INIS)

Nalezny, C.L.; Chapman, R.L.; Martinell, J.S.; Riordon, R.P.; Solbrig, C.W.

1979-01-01

Mass flow is an important measured variable in the Loss-of-Fluid Test (LOFT) Program. Large uncertainties in mass flow measurements in the LOFT piping during LOFT coolant experiments requires instrument testing in a transient two-phase flow loop that simulates the geometry of the LOFT piping. To satisfy this need, a transient two-phase flow loop has been designed and built. The load cell weighing system, which provides reference mass flow measurements, has been analyzed to assess its capability to provide the measurements. The analysis consisted of first performing a thermal-hydraulic analysis using RELAP4 to compute mass inventory and pressure fluctuations in the system and mass flow rate at the instrument location. RELAP4 output was used as input to a structural analysis code SAPIV which is used to determine load cell response. The computed load cell response was then smoothed and differentiated to compute mass flow rate from the system. Comparison between computed mass flow rate at the instrument location and mass flow rate from the system computed from the load cell output was used to evaluate mass flow measurement capability of the load cell weighing system. Results of the analysis indicate that the load cell weighing system will provide reference mass flows more accurately than the instruments now in LOFT

In beam test of a transient magnetic field based g factor setup

International Nuclear Information System (INIS)

Saxena, Mansi; Mandal, S.; Siwal, Davinder; Kumar, Chandan; Goyal, Savi; Garg, Ritika; Khushboo; Rohilla, Aman; Kumar, Naveen; Kumar, S.; Chamoli, S.; Mandal, A.; Kumar, Rajesh; Barua, P.; Kumar, R.; Gujjar, R.; Bala, Indu; Singh, R.P.; Muralithar, S.; Rehman, Anisur; Roy, Minakshi

2012-01-01

Magnetic moments or g factors provide substantial information on the microscopic structure of the nuclei. Since the g factor is very different in sign and magnitude for neutrons and protons, therefore they can serve as a good indicator as to which nucleon contributes most to the wave function of that state. There are different techniques available for measuring g factors depending on the lifetime of the state involved. Using transient field technique we can measure the g factor of nuclei having a lifetime of the order of several hundreds of femto seconds. To measure the g factor of such low lifetime states we have designed and fabricated a setup based on the Transient Field Technique Measurement

Mitigation of thermal transients by tube bundle inlet plenum design

International Nuclear Information System (INIS)

Oras, J.J.; Kasza, K.E.

1984-06-01

A multiphase program aimed at investigating the importance of thermal buoyancy to LMFBR steam-generator and heat-exchanger thermal hydraulics under low-flow transient conditions is being conducted in the Argonne Mixing Components Test Facility (MCTF) on a 60 0 sector shell-side flow model of the Westinghouse straight-tube steam generator being developed under the US/DOE large-component development program. A series of shell-side constant-flow thermal-downramp transient tests have been conducted focusing on the phenomenon of thermal-buoyancy-induced-flow channeling. In addition, it was discovered that a shell-inlet flow-distribution plenum can play a significant role in mitigating the severity of a thermal transient entering a steam generator or heat exchanger

Study of the initiation of subcooled boiling during power transients

International Nuclear Information System (INIS)

VanVleet, R.J.

1985-01-01

An experimental investigation of boiling initiation during power transients has been conducted for horizontal-cylinder heating elements in degassed distilled water. Platinum elements, 0.127 and 0.250 mm in diameter, were internally heated electrically at a controlled superficial heat flux (power applied divided by surface area) increasing linearly with time at rates of 0.035 and 0.35 MW/m 2 s and corresponding test durations of 20 and 2 seconds. Tests were carried out at saturation temperatures from 100 to 195 0 C with bulk fluid subcooling from 0 to 30 K. During the course of a power transient, element temperature and superficial heat flux were measured electrically and the boiling initiation time was determined optically. It was found that the conditions for boiling initiation depended strongly on the pressure-temperature history of the heating element and surround fluid prior to the transient. Boiling initiation times were found to agree qualitatively with predictions of a model based on the contact-angle hysteresis concept. Brief prepressurization prior to a transient was found to increase dramatically the temperature and heat flux required for boiling initiation because of deactivation of boiling initiation sites. However, sites were re-activated during the transient and, in subsequent tests without prepressurization, no elevation in boiling initiation conditions was observed and results were in quantitative agreement with predictions of the model

New modelling of transient well test and rate decline analysis for a horizontal well in a multiple-zone reservoir

International Nuclear Information System (INIS)

Nie, Ren-Shi; Guo, Jian-Chun; Jia, Yong-Lu; Zhu, Shui-Qiao; Rao, Zheng; Zhang, Chun-Guang

2011-01-01

The no-type curve with negative skin of a horizontal well has been found in the current research. Negative skin is very significant to transient well test and rate decline analysis. This paper first presents the negative skin problem where the type curves with negative skin of a horizontal well are oscillatory. In order to solve the problem, we propose a new model of transient well test and rate decline analysis for a horizontal well in a multiple-zone composite reservoir. A new dimensionless definition of r D is introduced in the dimensionless mathematical modelling under different boundaries. The model is solved using the Laplace transform and separation of variables techniques. In Laplace space, the solutions for both constant rate production and constant wellbore pressure production are expressed in a unified formula. We provide graphs and thorough analysis of the new standard type curves for both well test and rate decline analysis; the characteristics of type curves are the reflections of horizontal well production in a multiple-zone reservoir. An important contribution of our paper is that our model removed the oscillation in type curves and thus solved the negative skin problem. We also show that the characteristics of type curves depend heavily on the properties of different zones, skin factor, well length, formation thickness, etc. Our research can be applied to a real case study

Advanced oxidation protein products sensitized the transient receptor potential vanilloid 1 via NADPH oxidase 1 and 4 to cause mechanical hyperalgesia

Directory of Open Access Journals (Sweden)

Ruoting Ding

2016-12-01

Full Text Available Oxidative stress is a possible pathogenesis of hyperalgesia. Advanced oxidation protein products (AOPPs, a new family of oxidized protein compounds, have been considered as a novel marker of oxidative stress. However, the role of AOPPs in the mechanism of hyperalgesia remains unknown. Our study aims to investigate whether AOPPs have an effect on hyperalgesia and the possible underlying mechanisms. To identify the AOPPs involved, we induced hyperalgesia in rats by injecting complete Freund’s adjuvant (CFA in hindpaw. The level of plasma AOPPs in CFA-induced rats was 1.6-fold in comparison with what in normal rats (P<0.05. After intravenous injection of AOPPs-modified rat serum albumin (AOPPs-RSA in Sprague-Dawley rats, the paw mechanical thresholds, measured by the electronic von Frey system, significantly declined. Immunofluorescence staining indicated that AOPPs increased expressions of NADPH oxidase 1 (Nox1, NADPH oxidase 4 (Nox4, transient receptor potential vanilloid 1 (TRPV1 and calcitonin gene-related peptide (CGRP in the dorsal root ganglia (DRG tissues. In-vitro studies were performed on primary DRG neurons which were obtained from both thoracic and lumbar DRG of rats. Results indicated that AOPPs triggered reactive oxygen species (ROS production in DRG neurons, which were significantly abolished by ROS scavenger N-acetyl-l-cysteine (NAC and small-interfering RNA (siRNA silencing of Nox1 or Nox4. The expressions of Nox1, Nox4, TRPV1 and CGRP were significantly increased in AOPPs-induced DRG neurons. And relevant siRNA or inhibitors notably suppressed the expressions of these proteins and the calcium influxes in AOPPs-induced DRG neurons. In conclusion, AOPPs increased significantly in CFA-induced hyperalgesia rats and they activated Nox1/Nox4-ROS to sensitize TRPV1-dependent Ca2+ influx and CGRP release which led to inducing mechanical hyperalgesia.

Laboratory testing of ozone oxidation of Hanford site waste

International Nuclear Information System (INIS)

Delegard, C.H.; Stubbs, A.M.; Bolling, S.D.; Colby, S.A.

1994-01-01

Organic constituents in radioactive waste stored in underground tanks at the U.S. Department of Energy's Hanford Site provoke safety concerns arising from their low-temperature reactions with nitrate and nitrite oxidants. Destruction of the organics would eliminate both safety problems. Oxone oxidation was investigated to destroy organic species present in simulated and genuine waste from Hanford Site Tank 241-SY-101. Bench-scale tests showed high-shear mixing apparatus achieved efficient gas-to-solution mass transfer and utilization of the ozone reagent. Oxidations of nitrite (to form nitrate) and organic species were observed. The organics formed carbonate and oxalate as well as nitrate and nitrogen gas from organic nitrogen. Formate, acetate and oxalate were present both in source waste and as reaction intermediates. Metal species oxidations also were observed directly or inferred by solubilities. Chemical precipitations of metal ions such as strontium and americium occurred as the organic species were destroyed by ozone. Reaction stoichiometries were consistent with the reduction of one oxygen atom per ozone molecule

Lightning Pin Injection Testing on MOSFETS

Science.gov (United States)

Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.; Koppen, Sandra V.; Mielnik, John J.; Vaughan, Roger K.; Wysocki, Philip F.; Celaya, Jose R.; Saha, Sankalita

2009-01-01

Lightning transients were pin-injected into metal-oxide-semiconductor field-effect transistors (MOSFETs) to induce fault modes. This report documents the test process and results, and provides a basis for subsequent lightning tests. MOSFETs may be present in DC-DC power supplies and electromechanical actuator circuits that may be used on board aircraft. Results show that unprotected MOSFET Gates are susceptible to failure, even when installed in systems in well-shielded and partial-shielded locations. MOSFET Drains and Sources are significantly less susceptible. Device impedance decreased (current increased) after every failure. Such a failure mode may lead to cascading failures, as the damaged MOSFET may allow excessive current to flow through other circuitry. Preliminary assessments on a MOSFET subjected to 20-stroke pin-injection testing demonstrate that Breakdown Voltage, Leakage Current and Threshold Voltage characteristics show damage, while the device continues to meet manufacturer performance specifications. The purpose of this research is to develop validated tools, technologies, and techniques for automated detection, diagnosis and prognosis that enable mitigation of adverse events during flight, such as from lightning transients; and to understand the interplay between lightning-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation.

Incidental transients problems in reactor. Application examples

International Nuclear Information System (INIS)

Marbach, G.

1988-03-01

The fast neutron reactor fuel element qualification should be made not only for nominal operation but also for incidental and accidental transients. Different studies and tests permit to bring this justification such as simulation in hot laboratory after irradiation of irradiated pins or specific tests interpretation [fr

Association of transient hyperthyroidism and severity of hyperemesis gravidarum.

Science.gov (United States)

Malek, Nor Zila Hassan; Kalok, Aida; Hanafiah, Zainal Abidin; Shah, Shamsul Azhar; Ismail, Nor Azlin Mohamed

2017-03-23

Background Transient non-immune hyperthyroidism in early pregnancy is hyperthyroidism diagnosed for the first time in early pregnancy, without evidence of thyroid autoimmunity or clinical findings of Grave's disease and resolved spontaneously as the pregnancy progressed. Hyperemesis gravidarum (HG) is the commonest cause with 66%-73% of women with severe HG were found to have elevated thyroid function. Materials and methods We conducted a cross sectional study to determine the prevalence of transient hyperthyroidism in patients with hyperemesis gravidarum and its relation to the severity of nausea and vomiting. Severity of nausea and vomiting in pregnancy was assessed using the modified pregnancy-unique quantification of emesis (PUQE) scoring system. Each patient had urine and blood investigations which also included a full blood count and thyroid and renal function tests. Patients with abnormal thyroid function were retested at 20 weeks of gestation. The patients' demographic data, electrolyte levels, thyroid function and their respective PUQE score were analyzed. Results The prevalence of transient hyperthyroidism in women with hyperemesis gravidarum was 4.8%. Although there was a significant association between the severity of the PUQE score and hypokalemia (p = 0.001), there was no significant association with transient hyperthyroidism in early pregnancy (p = 0.072). Free T4 and TSH values of all women with transient hyperthyroidism were normalized by 20 weeks of gestation. Conclusion Transient hyperthyroidism in pregnancy is not significantly associated with the severity of the PUQE score. Women with transient hyperthyroidism in pregnancy are normally clinically euthyroid, hence a routine thyroid function test is unnecessary unless they exhibit clinical signs or symptoms of hyperthyroidism.

Critical heat flux phenomena in flow boiling during step wise and ramp wise power transients

International Nuclear Information System (INIS)

Celata, G.P.; Cumo, M.; D'Annibale, F.; Farello, G.E.; Abou Said, S.

1987-01-01

The present paper deals with the results of an experimental investigation of the forced flow critical heat flux during power transients in a vertically heated channel. Experiments were carried out with a Refrigerant-12 1oop employing a circular test section which was electrically and uniformly heated. The power transients were performed with the step-wise and ramp-wise increase of the power to the test section. The test parameters included several values of the initial power (before the transient) and the final power (at the end of the transient) in the case of step-wise transients and the slope of the ramp in the case of ramp-wise transients. The pressure and specific mass flow rate, which were kept constant during the power transient,were varied from 1.2 to 2.7 MPa and 850 to 1500 Kg/sm 2 , respectively. Correlations of the experimental data for the time-to-crisis in terms of the independent parameters of the system are also proposed and verified for different values of pressure,mass flow rate, and inlet subcooling

Volume 3. Base technology FSAR support document: prefailure transient behavior and failure threshold. Status report, January 1975

International Nuclear Information System (INIS)

Baars, R.E.; Culley, G.E.; Davis, R.T.; Henderson, R.G.; Scott, J.H.

1975-11-01

The FFTF fuel pin design and fabrication data, irradiation histories, and postirradiation examination results are summarized for the HEDL/TREAT transient test experimental programs. For each experiment, the data include: (a) fuel pin fabrication parameters, (b) steady-state irradiation history, (c) transient test design conditions, (d) transient test data, and (e) postirradiation examination results

Transient effects in SIMS analysis of Si with Cs sup + at high incidence angles Secondary ion yield variations

CERN Document Server

Heide, P A W

2002-01-01

Secondary ion mass spectrometry (SIMS) depth profile analysis of Si wafers using 1 keV Cs sup + primary ions at large incidence angles (80 deg. ) is plagued by unusually strong transient effects (variations in both sputter and ion yields). Analysis of a native oxide terminated Si wafer with and without the aid of an O sub 2 leak, and an Ar sup + pre-sputtered wafer revealed correlations between the implanted Cs content and various secondary ion intensities consistent with that expected from a resonance charge transfer process (that assumed by the electron tunneling model). Cs concentrations were defined through X-ray photoelectron spectroscopy of the sputtered surface from SIMS profiles terminated within the transient region. These scaled with the surface roughening occurring under these conditions and can be explained as resulting from the associated drop in sputter rates. An O induced transient effect from the native oxide was also identified. Characterization of these effects allowed the reconstruction of ...

FFTF fuel pin design procedure verification for transient operation

International Nuclear Information System (INIS)

Baars, R.E.

1975-05-01

The FFTF design procedures for evaluating fuel pin transient performance are briefly reviewed, and data where available are compared with design procedure predictions. Specifically, burst conditions derived from Fuel Cladding Transient Tester (FCTT) tests and from ANL loss-of-flow tests are compared with burst pressures computed using the design procedure upon which the cladding integrity limit was based. Failure times are predicted using the design procedure for evaluation of rapid reactivity insertion accidents, for five unterminated TREAT experiments in which well characterized fuel failures were deliberately incurred. (U.S.)

The Application of a Modified d-ROMs Test for Measurement of Oxidative Stress and Oxidized High-Density Lipoprotein

Directory of Open Access Journals (Sweden)

Fumiaki Ito

2017-02-01

Full Text Available Reactive oxygen species (ROS are involved in the initiation and progression of atherosclerosis. ROS-derived hydroperoxides, as an indicator of ROS production, have been measured by using the diacron reactive oxygen metabolites (d-ROMs test, which requires iron-containing transferrin in the reaction mixture. In this study we developed a modified d-ROMs test, termed the Fe-ROMs test, where iron ions were exogenously added to the reaction mixture. This modification is expected to exclude the assay variation that comes from different blood iron levels in individuals. In addition, this Fe-ROMs test was helpful for determining the class of plasma lipoproteins that are hydroperoxidized. Low-density lipoprotein/very low-density lipoprotein (LDL/VLDL and high-density lipoprotein (HDL were purified by use of an LDL/VLDL purification kit and the dextran sulfate-Mg2+ precipitation method, respectively; their hydroperoxide contents were assessed by performing the Fe-ROMs test. The majority of the hydroperoxides were detected only in the HDL fraction, not in the LDL/VLDL. Further detailed analysis of HDLs by size-exclusion high-performance liquid chromatography revealed that the hydroperoxide-containing molecules were small-sized HDLs. Because HDL was shown to be the principal vehicle for the plasma hydroperoxides, this Fe-ROMs test is a beneficial method for the assessment of oxidized-HDL levels. Indeed, Fe-ROMs levels were strongly associated with the levels of oxidized HDL, which were determined by performing the malondialdehyde-modified HDL enzyme immunoassay. In conclusion, the Fe-ROMs test using plasma itself or the HDL fraction after dextran sulfate-Mg2+ precipitation is useful to assess the functionality of HDL, because the oxidation of HDL impairs its antiatherogenic capacity.

Cladding properties under simulated fuel pin transients

International Nuclear Information System (INIS)

Hunter, C.W.; Johnson, G.D.

1975-01-01

A description is given of the HEDL fuel pin testing program utilizing a recently developed Fuel Cladding Transient Tester (FCTT) to generate the requisite mechanical property information on irradiated and unirradiated fast reactor fuel cladding under temperature ramp conditions. The test procedure is described, and data are presented

Air Oxidation Behaviors of Zircaloy-4 Cladding During a LOCA In Spent Fuel Pool

International Nuclear Information System (INIS)

Bang, Je Geon; Chun, Tae Hyun; Kim, Sun Ki; Koo, Yang Hyun

2014-01-01

It is well known that air oxidation induces a serious degradation of the Zircaloy cladding material, compared with steam oxidation. From the oxidant point of view, in comparison with steam, chemical heat release during oxidation in air is higher by 80%, which may lead to a more rapid degradation of the Zircaloy cladding, and further evolution of the accident.. Additionally, the oxidation kinetics in air is much faster than in steam due to the formation of non-protective oxide layer. From the safety point of view, the barrier effect of the cladding against release of fission products is lost much earlier in air compared to steam. The objective of this study is to investigate the oxidation behaviors of fuel cladding in two different conditions such as isothermal and transient condition and to generate its kinetic data under an accident condition in the spent fuel pool. In this study, the oxidation behaviors and its kinetics of the Zircaloy-4 were investigated in air environment for various air ingress scenarios in the temperature range 600 .deg. C-1,400 .deg. C by thermo-gravimetric analysis. In this study, the oxidation behaviors of the Zircaloy-4 for both isothermal condition and transient condition were investigated in air environment. In comparison with isothermal condition, the retardation of oxidation rate in transient condition was observed at both 1,200 .deg. C and 1,400 .deg. C. This seems to be ascribed to the effect of thin oxide formed during a heating

Transient Go: A Mobile App for Transient Astronomy Outreach

Science.gov (United States)

Crichton, D.; Mahabal, A.; Djorgovski, S. G.; Drake, A.; Early, J.; Ivezic, Z.; Jacoby, S.; Kanbur, S.

2016-12-01

Augmented Reality (AR) is set to revolutionize human interaction with the real world as demonstrated by the phenomenal success of `Pokemon Go'. That very technology can be used to rekindle the interest in science at the school level. We are in the process of developing a prototype app based on sky maps that will use AR to introduce different classes of astronomical transients to students as they are discovered i.e. in real-time. This will involve transient streams from surveys such as the Catalina Real-time Transient Survey (CRTS) today and the Large Synoptic Survey Telescope (LSST) in the near future. The transient streams will be combined with archival and latest image cut-outs and other auxiliary data as well as historical and statistical perspectives on each of the transient types being served. Such an app could easily be adapted to work with various NASA missions and NSF projects to enrich the student experience.

Comparison of nine blood tests and transient elastography for liver fibrosis in chronic hepatitis C: the ANRS HCEP-23 study.

Science.gov (United States)

Zarski, Jean-Pierre; Sturm, Nathalie; Guechot, Jérôme; Paris, Adeline; Zafrani, Elie-Serge; Asselah, Tarik; Boisson, Renée-Claude; Bosson, Jean-Luc; Guyader, Dominique; Renversez, Jean-Charles; Bronowicki, Jean-Pierre; Gelineau, Marie-Christine; Tran, Albert; Trocme, Candice; De Ledinghen, Victor; Lasnier, Elisabeth; Poujol-Robert, Armelle; Ziegler, Frédéric; Bourliere, Marc; Voitot, Hélène; Larrey, Dominique; Rosenthal-Allieri, Maria Alessandra; Fouchard Hubert, Isabelle; Bailly, François; Vaubourdolle, Michel

2012-01-01

Blood tests and transient elastography (Fibroscan™) have been developed as alternatives to liver biopsy. This ANRS HCEP-23 study compared the diagnostic accuracy of nine blood tests and transient elastography (Fibroscan™) to assess liver fibrosis, vs. liver biopsy, in untreated patients with chronic hepatitis C (CHC). This was a multicentre prospective independent study in 19 French University hospitals of consecutive adult patients having simultaneous liver biopsy, biochemical blood tests (performed in a centralized laboratory) and Fibroscan™. Two experienced pathologists independently reviewed the liver biopsies (mean length=25±8.4 mm). Performance was assessed using ROC curves corrected by Obuchowski's method. Fibroscan™ was not interpretable in 113 (22%) patients. In the 382 patients having both blood tests and interpretable Fibroscan™, Fibroscan™ performed similarly to the best blood tests for the diagnosis of significant fibrosis and cirrhosis. Obuchowski's measure showed Fibrometer® (0.86), Fibrotest® (0.84), Hepascore® (0.84), and interpretable Fibroscan™ (0.84) to be the most accurate tests. The combination of Fibrotest®, Fibrometer®, or Hepascore® with Fibroscan™ or Apri increases the percentage of well classified patients from 70-73% to 80-83% for significant fibrosis, but for cirrhosis a combination offers no improvement. For the 436 patients having all the blood tests, AUROC's ranged from 0.82 (Fibrometer®) to 0.75 (Hyaluronate) for significant fibrosis, and from 0.89 (Fibrometer® and Hepascore®) to 0.83 (FIB-4) for cirrhosis. Contrarily to blood tests, performance of Fibroscan™ was reduced due to uninterpretable results. Fibrotest®, interpretable Fibroscan™, Fibrometer®, and Hepascore® perform best and similarly for diagnosis of significant fibrosis and cirrhosis. Copyright © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Development of MCP transient operation strategy for the SMART-P

International Nuclear Information System (INIS)

Yoo, S. E.; Choi, B. S.; Kang, H. O.; Yoon, J. H.; Ji, S. K.

2003-01-01

SMART-P MCP(Main Coolant Pump) transient operation strategies are developed. A Modular Modeling System (MMS) computer code is used for the evaluation of the developed operation strategies. In the SMART-P, normal operating modes are classified into MCP high speed(3600 rpm) mode and MCP low speed mode. Also, natural circulation mode is defined as a performance test case. MCP operation transients occur when changing modes from one to another, and system parameters(core power, system pressure, temperature) are having transients. These transients affect on system performance and, in some cases, limit system operation. In this study, MCP operation strategies are developed and obtained acceptable results

Transient performance of S-prism

International Nuclear Information System (INIS)

Dubberley, A.E.; Boardman, C.E.; Gamble, R.E.; Hiu, M.M.; Lipps, A.J.; Wu, T.

2001-01-01

S-PRISM is an advanced Fast Reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test of a single Nuclear Steam Supply System (NSSS) for design certification at minimum cost and risk. Based on the success of the previous DOE sponsored Advanced Liquid Metal Reactor (ALMR) program GE has continued to develop and assess the technical viability and economic potential of an up-rated plant called SuperPRISM (S-PRISM). This paper presents the results of transient analyses performed to assess the ability of S-PRISM to accommodate severe accident initiator events. A unique safety capability of S-PRISM is accommodation of the ''higher probability'' accident initiators that led to core melt accidents in prior large LMRs. These events, the Anticipated Transients Without Scram (ATWS) events, are thus the focus of passive safety confirmation analyses. The events included in this assessment are: Unprotected Loss of Flow, Unprotected Loss of Heat Sink, Unprotected Loss of Flow and Heat sink, Unprotected Transient Overpower and Unprotected Safe Shutdown Earthquake. (author)

Brain aluminium accumulation and oxidative stress in the presence of calcium silicate dental cements.

Science.gov (United States)

Demirkaya, K; Demirdöğen, B Can; Torun, Z Öncel; Erdem, O; Çırak, E; Tunca, Y M

2017-10-01

Mineral trioxide aggregate (MTA) is a calcium silicate dental cement used for various applications in dentistry. This study was undertaken to test whether the presence of three commercial brands of calcium silicate dental cements in the dental extraction socket of rats would affect the brain aluminium (Al) levels and oxidative stress parameters. Right upper incisor was extracted and polyethylene tubes filled with MTA Angelus, MTA Fillapex or Theracal LC, or left empty for the control group, were inserted into the extraction socket. Rats were killed 7, 30 or 60 days after operation. Brain tissues were obtained before killing. Al levels were measured by atomic absorption spectrometry. Thiobarbituric acid reactive substances (TBARS) levels, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were determined using spectrophotometry. A transient peak was observed in brain Al level of MTA Angelus group on day 7, while MTA Fillapex and Theracal LC groups reached highest brain Al level on day 60. Brain TBARS level, CAT, SOD and GPx activities transiently increased on day 7 and then returned to almost normal levels. This in vivo study for the first time indicated that initial washout may have occurred in MTA Angelus, while element leaching after the setting is complete may have taken place for MTA Fillapex and Theracal LC. Moreover, oxidative stress was induced and antioxidant enzymes were transiently upregulated. Further studies to search for oxidative neuronal damage should be done to completely understand the possible toxic effects of calcium silicate cements on the brain.

Steady and transient regimes in hydropower plants

Science.gov (United States)

Gajic, A.

2013-12-01

Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock.

Steady and transient regimes in hydropower plants

International Nuclear Information System (INIS)

Gajic, A

2013-01-01

Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock

Verification and validation of COBRA-SFS transient analysis capability

International Nuclear Information System (INIS)

Rector, D.R.; Michener, T.E.; Cuta, J.M.

1998-05-01

This report provides documentation of the verification and validation testing of the transient capability in the COBRA-SFS code, and is organized into three main sections. The primary documentation of the code was published in September 1995, with the release of COBRA-SFS, Cycle 2. The validation and verification supporting the release and licensing of COBRA-SFS was based solely on steady-state applications, even though the appropriate transient terms have been included in the conservation equations from the first cycle. Section 2.0, COBRA-SFS Code Description, presents a capsule description of the code, and a summary of the conservation equations solved to obtain the flow and temperature fields within a cask or assembly model. This section repeats in abbreviated form the code description presented in the primary documentation (Michener et al. 1995), and is meant to serve as a quick reference, rather than independent documentation of all code features and capabilities. Section 3.0, Transient Capability Verification, presents a set of comparisons between code calculations and analytical solutions for selected heat transfer and fluid flow problems. Section 4.0, Transient Capability Validation, presents comparisons between code calculations and experimental data obtained in spent fuel storage cask tests. Based on the comparisons presented in Sections 2.0 and 3.0, conclusions and recommendations for application of COBRA-SFS to transient analysis are presented in Section 5.0

Hazard classification for the supercritical water oxidation test bed. Revision 1

International Nuclear Information System (INIS)

Ramos, A.G.

1994-10-01

A hazard classification of ''routinely accepted by the public'' has been determined for the operation of the supercritical water oxidation test bed at the Idaho National Engineering Laboratory. This determination is based on the fact that the design and proposed operation meet or exceed appropriate national standards so that the risks are equivalent to those present in similar activities conducted in private industry. Each of the 17 criteria for hazards ''routinely accepted by the public,'' identified in the EG and G Idaho, Inc., Safety Manual, were analyzed. The supercritical water oxidation (SCWO) test bed will treat simulated mixed waste without the radioactive component. It will be designed to operate with eight test wastes. These test wastes have been chosen to represent a broad cross-section of candidate mixed wastes anticipated for storage or generation by DOE. In particular, the test bed will generate data to evaluate the ability of the technology to treat chlorinated waste and other wastes that have in the past caused severe corrosion and deposition in SCWO reactors

Response of air cleaning system dampers and blowers to simulated tornado transients

International Nuclear Information System (INIS)

Gregory, W.; Idar, E.; Smith, P.; Hensel, E.; Smith, E.

1985-01-01

The effects of tornado-like pressure transients upon dampers and blowers in nuclear air cleaning systems were studied. For the dampers pressure drop as a function of flow rate was obtained and an empirical relationship developed. Transient response was examined for several types of dampers, as was structural integrity. Both centrifugal and axi-vane blowers were tested and transient characteristic curves were generated in outrunning and backflow situations. The transient characteristic curves do not necessarily match the quasi-steady characteristic curves

Polycrystalline oxides formation during transient oxidation of (001) Cu-Ni binary alloys studied by in situ TEM and XRD

International Nuclear Information System (INIS)

Yang, J.C.; Li, Z.Q.; Sun, L.; Zhou, G.W.; Eastman, J.A.; Fong, D.D.; Fuoss, P.H.; Baldo, P.M.; Rehn, L.E.; Thompson, L.J.

2009-01-01

The nucleation and growth of Cu 2 O and NiO islands due to oxidation of Cu x Ni 1-x (001) films were monitored, at various temperatures, by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM) and in situ synchrotron X-ray diffraction (XRD). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands formed with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. In situ XRD experiments revealed that NiO formed first epitaxially, then other orientations appeared, and finally polycrystalline Cu 2 O developed as the oxidation pressure was increased. The segregation of Ni and Cu towards or away, respectively, from the alloy surface during oxidation could disrupt the surface and cause polycrystalline oxide formation.

Toughness testing and high-temperature oxidation evaluations of advanced alloys for core internals

Energy Technology Data Exchange (ETDEWEB)

Tan, Lizhen [ORNL; Pint, Bruce A [ORNL; Chen, Xiang [ORNL

2016-09-16

Alloy X-750 was procured from Carpenter Technology and Bodycote in this year. An appropriate TMT was developed on Alloy 439 to obtain materials with refined grain size for property screening tests. Charpy V-notch impact tests were completed for the three ferritic steels Grade 92, Alloy 439, and 14YWT. Fracture toughness tests at elevated temperatures were completed for 14YWT. The tests will be completed for the other alloys in next fiscal year. Steam oxidation tests of the three ferritic steels, 316L, and Zr–2.5Nb have been completed. The steam tests of the Ni-based superalloys and the other austenitic stainless steels will be continued and finished in next fiscal year. Performance ranking in terms of steam oxidation resistance and impact/fracture toughness of the alloys will be deduced.

Empirical method to calculate Clinch River Breeder Reactor (CRBR) inlet plenum transient temperatures

International Nuclear Information System (INIS)

Howarth, W.L.

1976-01-01

Sodium flow enters the CRBR inlet plenum via three loops or inlets. An empirical equation was developed to calculate transient temperatures in the CRBR inlet plenum from known loop flows and temperatures. The constants in the empirical equation were derived from 1/4 scale Inlet Plenum Model tests using water as the test fluid. The sodium temperature distribution was simulated by an electrolyte. Step electrolyte transients at 100 percent model flow were used to calculate the equation constants. Step electrolyte runs at 50 percent and 10 percent flow confirmed that the constants were independent of flow. Also, a transient was tested which varied simultaneously flow rate and electrolyte. Agreement of the test results with the empirical equation results was good which verifies the empirical equation

Study of the Rancimat test method in measuring the oxidation stability of biodiesel ester and blends

Energy Technology Data Exchange (ETDEWEB)

Berthiaume, D.; Tremblay, A. [Oleotek Inc., Thetford Mines, PQ (Canada)

2006-11-15

This paper provided details of a study conducted to examine the oxidation stability of biodiesel blends. The study tested samples of canola oil, soybean oil, fish oil, yellow grease, and tallow. The EN 14112 (Rancimat) method was used to compare oxidation stability results obtained in previous tests conducted in the United States and Europe. The aim of the study was also to evaluate the influence of peroxide value (PV), acid value (AV) and feedstock source on the the oxidative stability of different samples. The study also evaluated the possibility of developing a validated test method developed from the EN 14112 methods to specifically consider biodiesel blends. Results of the study indicated that the Rancimat method was not suitable for measuring the oxidation stability of biodiesels blended with petrodiesels. No direct correlation between oxidative stability and PV or AV was observed. It was concluded that fatty acid distribution was not a principal factor in causing changes in oxidation stability. 22 refs., 3 tabs., 1 fig.

Newborn hearing screening with transient evoked otoacoustic emissions and automatic auditory brainstem response

Directory of Open Access Journals (Sweden)

Renata Mota Mamede de Carvallo

2008-09-01

Full Text Available Objective: The aim of the present investigation was to check Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests applied together in regular nurseries and Newborn Intensive Care Units (NICU, as well as to describe and compare the results obtained in both groups. Methods: We tested 150 newborns from regular nurseries and 70 from NICU. Rresults: The newborn hearing screening results using Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests could be applied to all babies. The “pass” result for the group of babies from the nursery was 94.7% using Transient Evoked Otoacoustic Emissions and 96% using Automatic Auditory Brainstem Response. The newborn intensive care unit group obtained 87.1% on Transient Evoked Otoacoustic Emissions and 80% on the Automatic Auditory Brainstem Response, and there was no statistical difference between the procedures when the groups were evaluated individually. However, comparing the groups, Transient Evoked Otoacoustic Emissions were presented in 94.7% of the nursery babies and in 87.1% in the group from the newborn intensive care unit. Considering the Automatic Auditory Brainstem Response, we found 96 and 87%, respectively. Cconclusions: Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response had similar “pass” and “fail” results when the procedures were applied to neonates from the regular nursery, and the combined tests were more precise to detect hearing impairment in the newborn intensive care unit babies.

Perform Tests and Document Results and Analysis of Oxide Layer Effects and Comparisons

Energy Technology Data Exchange (ETDEWEB)

Collins, E. D. [ORNL; DelCul, G. D. [ORNL; Spencer, B. B. [ORNL; Hunt, R. D. [ORNL; Ausmus, C. [ORNL

2014-08-30

During the initial feasibility test using actual used nuclear fuel (UNF) cladding in FY 2012, an incubation period of 30–45 minutes was observed in the initial dry chlorination. The cladding hull used in the test had been previously oxidized in a dry air oxidation pretreatment prior to removal of the fuel. The cause of this incubation period was attributed to the resistance to chlorination of an oxide layer imparted by the dry oxidation pretreatment on the cladding. Subsequently in 2013, researchers at the Korea Atomic Energy Institute (KAERI) reported on their chlorination study [R1] on ~9-gram samples of unirradiated ZirloTM cladding tubes that had been previously oxidized in air at 500oC for various time periods to impart oxide layers of varying thickness. In early 2014, discussions with Indefinite Delivery, Indefinite Quantity (IDIQ) contracted technical consultants from Westinghouse described their previous development (and patents) [R2] on methods of chemical washing to remove some or all of the hydrous oxide layer imparted on UNF cladding during irradiation in light water reactors (LWRs) . Thus, the Oak Ridge National Laboratory (ORNL) study, described herein, was planned to extend the KAERI study on the effects of anhydrous oxide layers, but on larger ~100-gram samples of unirradiated zirconium alloy cladding tubes, and to investigate the effects of various methods of chemical pretreatment prior to chlorination with 100% chlorine on the average reaction rates and Cl2 usage efficiencies.

On the kinetics of the aluminum-water reaction during exposure in high-heat flux test loops: 1, A computer program for oxidation calculations

International Nuclear Information System (INIS)

Pawel, R.E.

1988-01-01

The ''Griess Correlation,'' in which the thickness of the corrosion product on aluminum alloy surfaces is expressed as a function of time and temperature for high-flux-reactor conditions, was rewritten in the form of a simple, general rate equation. Based on this equation, a computer program that calculates oxide-layer thickness for any given time-temperature transient was written. 4 refs

A pilot application of the RELAP file to the steady state and transient analysis of a test section inside the BR2 reactor

International Nuclear Information System (INIS)

Ferri, M. G.; D'Auria, F.; Forasassi, G.; Giot, M.

2000-01-01

BR2 is a material test reactor sited in the Belgian Nuclear Research Centre in Mol. The main research programs carried out in BR2 are related to the safety of nuclear reactor structural materials and fuels, in normal and accidental conditions, plant lifetime evaluation and ageing of components. In this framework, a computer program that allows the performance of detailed, steady state analysis of several kinds of in-pile sections with an axisymmetrical geometry has been developed. Furthermore, comparing its results with those of the well known, extensively used, Relap5/Mod 3.2 code on a test problem has validated this program. This was performed in three steps: 1. modalisation development of a subsystem of a typical in-pile section. 2. steady state analysis and comparison with the above-mentioned program. 3. transient simulation of the same system; the considered transient consists of a loss of coolant flow. (author)

Analytical prediction and experimental verification of reactor safety system injection transient

International Nuclear Information System (INIS)

Roy, B.N.; Nomm, E.

1991-01-01

This paper describes the computer code that was developed for thermal hydraulic transient analysis of mixed phase fluid system and the flow tests that were carried out to validate the Code. A full scale test facility was designed to duplicate the Supplementary Shutdown System (SSS) of Savannah River Production Reactors. Several steady state and dynamic flow tests were conducted simulating the actual reactor injection transients. A dynamic multiphase fluid flow code was developed and validated with experimental results and utilized for system performance predictions and development of technical specifications for reactors. 3 refs

Supercritical water oxidation data acquisition testing. Final report, Volume II

International Nuclear Information System (INIS)

1996-11-01

Supercritical Water Oxidation (SCWO) technology holds great promise for treating mixed wastes, in an environmentally safe and efficient manner. In the spring of 1994 the US Department of Energy (DOE), Idaho Operations Office awarded Stone ampersand Webster Engineering Corporation, of Boston Massachusetts and its sub-contractor MODAR, Inc. of Natick Massachusetts a Supercritical Water Oxidation Data Acquisition Testing (SCWODAT) program. The SCWODAT program was contracted through a Cooperative Agreement that was co-funded by the US Department of Energy and the Strategic Environmental Research and Development Program. The SCWODAT testing scope outlined by the DOE in the original Cooperative Agreement and amendments thereto was initiated in June 1994 and successfully completed in December 1995. The SCWODAT program provided further information and operational data on the effectiveness of treating both simulated mixed waste and typical Navy hazardous waste using the MODAR SCWO technology

Switching transients in a superconducting coil

International Nuclear Information System (INIS)

Owen, E.W.; Shimer, D.W.

1983-01-01

A study is made of the transients caused by the fast dump of large superconducting coils. Theoretical analysis, computer simulation, and actual measurements are used. Theoretical analysis can only be applied to the simplest of models. In the computer simulations two models are used, one in which the coil is divided into ten segments and another in which a single coil is employed. The circuit breaker that interrupts the current to the power supply, causing a fast dump, is represented by a time and current dependent conductance. Actual measurements are limited to measurements made incidental to performance tests on the MFTF Yin-yang coils. It is found that the breaker opening time is the critical factor in determining the size and shape of the transient. Instantaneous opening of the breaker causes a lightly damped transient with large amplitude voltages to ground. Increasing the opening time causes the transient to become a monopulse of decreasing amplitude. The voltages at the external terminals are determined by the parameters of the external circuit. For fast opening times the frequency depends on the dump resistor inductance, the circuit capacitance, and the amplitude on the coil current. For slower openings the dump resistor inductance and the current determine the amplitude of the voltage to ground at the terminals. Voltages to ground are less in the interior of the coil, where transients related to the parameters of the coil itself are observed

Power Burst Facility Severe Fuel Damage test series

International Nuclear Information System (INIS)

Buescher, B.J.; Osetek, D.J.; Ploger, S.A.

1982-01-01

The Severe Fuel Damage (SFD) tests planned for the Power Burst Facility (PBF) are described. Bundles containing 32 zircaloy-clad, PWR-type fuel rods will be subjected to severe overheating transients in a high-pressure, superheated-steam environment. Cladding temperatures are expected to reach 2400 0 K, resulting in cladding ballooning and rupture, severe cladding oxidation, cladding melting, fuel dissolution, fuel rod fragmentation, and possibly, rubble bed formation. An experiment effluent collection system is being installed and the PBF fission product monitoring system is being upgraded to meet the special requirements of the SFD tests. Scoping calculations were performed to evaluate performance of the SFD test design and to establish operational requirements for the PBF loop

Solution-processed single-walled carbon nanotube field effect transistors and bootstrapped inverters for disintegratable, transient electronics

Energy Technology Data Exchange (ETDEWEB)

Jin, Sung Hun, E-mail: harin74@gmail.com, E-mail: jhl@snu.ac.kr, E-mail: jrogers@illinois.edu; Shin, Jongmin; Cho, In-Tak; Lee, Jong-Ho, E-mail: harin74@gmail.com, E-mail: jhl@snu.ac.kr, E-mail: jrogers@illinois.edu [Department of Electrical and Computer Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Han, Sang Youn [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Display R and D Center, Samsung Display Co., Yongin-city, Gyeongki-do 446–711 (Korea, Republic of); Lee, Dong Joon; Lee, Chi Hwan; Rogers, John A., E-mail: harin74@gmail.com, E-mail: jhl@snu.ac.kr, E-mail: jrogers@illinois.edu [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

2014-07-07

This paper presents materials, device designs, and physical/electrical characteristics of a form of nanotube electronics that is physically transient, in the sense that all constituent elements dissolve and/or disperse upon immersion into water. Studies of contact effects illustrate the ability to use water soluble metals such as magnesium for source/drain contacts in nanotube based field effect transistors. High mobilities and on/off ratios in transistors that use molybdenum, silicon nitride, and silicon oxide enable full swing characteristics for inverters at low voltages (∼5 V) and with high gains (∼30). Dissolution/disintegration tests of such systems on water soluble sheets of polyvinyl alcohol demonstrate physical transience within 30 min.

Solution-processed single-walled carbon nanotube field effect transistors and bootstrapped inverters for disintegratable, transient electronics

International Nuclear Information System (INIS)

Jin, Sung Hun; Shin, Jongmin; Cho, In-Tak; Lee, Jong-Ho; Han, Sang Youn; Lee, Dong Joon; Lee, Chi Hwan; Rogers, John A.

2014-01-01

This paper presents materials, device designs, and physical/electrical characteristics of a form of nanotube electronics that is physically transient, in the sense that all constituent elements dissolve and/or disperse upon immersion into water. Studies of contact effects illustrate the ability to use water soluble metals such as magnesium for source/drain contacts in nanotube based field effect transistors. High mobilities and on/off ratios in transistors that use molybdenum, silicon nitride, and silicon oxide enable full swing characteristics for inverters at low voltages (∼5 V) and with high gains (∼30). Dissolution/disintegration tests of such systems on water soluble sheets of polyvinyl alcohol demonstrate physical transience within 30 min.

Testing IH Instrumentation: Analysis of 1996-1998 Tank Ventilation Data in Terms of Characterizing a Transient Release

International Nuclear Information System (INIS)

Droppo, James G.

2004-01-01

An analysis is conducted of the 1996-1998 Hanford tank ventilation studies of average ventilation rates to help define characteristics of shorter term releases. This effort is being conducted as part of the design of tests of Industrial Hygiene's (IH) instrumentation ability to detect transient airborne plumes from tanks using current deployment strategies for tank operations. This analysis has improved our understanding of the variability of hourly average tank ventilation processes. However, the analysis was unable to discern the relative importance of emissions due to continuous releases and short-duration bursts of material. The key findings are as follows: (1) The ventilation of relatively well-sealed, passively ventilated tanks appears to be driven by a combination of pressure, buoyancy, and wind influences. The results of a best-fit analysis conducted with a single data set provide information on the hourly emission variability that IH instrumentation will need to detect. (2) Tank ventilation rates and tank emission rates are not the same. The studies found that the measured infiltration rates for a single tank are often a complex function of air exchanges between tanks and air exchanges with outdoor air. This situation greatly limits the usefulness of the ventilation data in defining vapor emission rates. (3) There is no evidence in the data to discern if the routine tank vapor releases occur over a short time (i.e., a puff) or over an extended time (i.e., continuous releases). Based on this analysis of the tank ventilation studies, it is also noted that (1) the hourly averaged emission peaks from the relatively well-sealed passively-vented tanks (such as U-103) are not a simple function of one meteorological parameter--but the peaks often are the result of the coincidence of temporal maximums in pressure, temperature, and wind influences and (2) a mechanistic combination modeling approach and/or field studies may be necessary to understand the short

Thermal-hydraulic tests with out-of-pile test facility for BOCA development

International Nuclear Information System (INIS)

Kitagishi, Shigeru; Aoyama, Masashi; Tobita, Masahiro; Inaba, Yoshitomo; Yamaura, Takayuki

2012-01-01

The fuel transient test facility was prepared for power ramping tests of light-water-reactor (LWR) fuels in the Japan Materials Testing Reactor (JMTR) under a contract project with the Nuclear Industrial Safety Agent (NISA) of the Ministry of Economy, Trade and Industry (METI). It is necessary to develop high accuracy analysis procedure for power ramping tests after restart of the JMTR. The out-of-pile test facility to simulate thermal-hydraulic conditions of the fuel transient test facility was therefore developed. Applicability of the analysis code ACE-3D was examined for thermal-hydraulic analysis of power ramping tests for 10x10 BWR fuels by the fuel transient test facility. As the results, the calculated temperature was 304°C in comparison with measured value of 304.9-317.4°C in the condition of 600 W/cm. There is a bright prospect of high accuracy power ramping tests by the fuel transient test facility in JMTR. (author)

Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

DEFF Research Database (Denmark)

Auer, C.; Lang, M.; Couturier, K.

2015-01-01

The market penetration of fuel and electrolysis cell energy systems in Europe requires the development of reliable assessment, testing and prediction of performance and durability of solid oxide cells and stacks (SOC). To advance in this field the EU-project “SOCTESQA” was launched in May 2014...... and dynamic operating conditions. The application specific test programs are created by combining several of these test modules. In a next step defined test modules will be applied for the initial test bench validation, which will be improved by several validation loops. The final test protocols...

SOCTESQA - Solid Oxide Cell and Stack Testing, Safety and Quality Assurance

OpenAIRE

Lang, Michael; Auer, Corinna; Couturier, Karine; Nielsen, Eva Ravn; Mc Phail, Stephen; Kotsionopoulos, Nikolaos; FU, Qingxi; Liu, Qinglin

2015-01-01

For the successful market penetration of high temperature solid oxide fuel/electrolysis cell energy systems it is necessary to increase the quality assurance and the reliable assessment of the corresponding cells and stacks. Therefore in May 2014 the EU-funded project SOCTESQA was launched. Partners from different countries in Europe and one external party from Singapore are working together to develop uniform and industry wide test procedures and programs for solid oxide cell/stack (SOC) ass...

Current interruption transients calculation

CERN Document Server

Peelo, David F

2014-01-01

Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

International Nuclear Information System (INIS)

Pedersen, Michael; Aarhus Univ.; Univ. Victor Segalen Bordeaux 2; Laustsen, Christoffer; Perot, Vincent; Grenier, Nicolas; Basseau, Fabrice; Moonen, Chrit

2010-01-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2 * , and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2 * was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Michael [Aarhus Univ. Hospital (Denmark). MR Research Centre; Aarhus Univ. (Denmark). Inst. of Experimental Clinical Medicine; Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231; Laustsen, Christoffer [Aarhus Univ. Hospital (Denmark). MR Research Centre; Perot, Vincent; Grenier, Nicolas [Hopital Pellegrin, CHU Bordeaux (France). Service d' Imagerie Diagnostique et Therapeutique de l' Adulte; Basseau, Fabrice; Moonen, Chrit [Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231

2010-07-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2{sup *}, and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2{sup *} was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

RETRAN experience with BWR transients at Yankee Atomic Electric Company

International Nuclear Information System (INIS)

Ansari, A.A.F.; Cronin, J.T.; Slifer, B.C.

1981-01-01

Yankee Atomic Electric Company is actively involved in the development of licensing methods for BWR's. The computer code chosen for analyzing system response under transient conditions is RETRAN. This paper describes the RETRAN model developed for Vermont Yankee, and the results of the RETRAN checkout and qualification that has been achieved at YAEC through comparison of RETRAN predictions to the startup test results performed at the plant as part of the 100% power startup test program. In addition, abnormal operational transients typically analyzed for licensing are also presented

In situ measurement of methane oxidation in groundwater by using natural-gradient tracer tests

International Nuclear Information System (INIS)

Smith, R.L.; Howes, B.L.; Garabedian, S.P.

1991-01-01

Methane oxidation was measured in an unconfined sand and gravel aquifer (Cape Cod, Mass.) by using in situ natural-gradient tracer tests at both a pristine, oxygenated site and an anoxic, sewage-contaminated site. The tracer sites were equipped with multilevel sampling devices to create target grids of sampling points; the injectate was prepared with groundwater from the tracer site to maintain the same geochemical conditions. Methane oxidation was calculated from breakthrough curves of methane relative to halide and inert gas (hexafluoroethane) tracers and was confirmed by the appearance of 13 C-enriched carbon dioxide in experiments in which 13 C-enriched methane was used as the tracer. A V max for methane oxidation could be calculated when the methane concentration was sufficiently high to result in zero-order kinetics throughout the entire transport interval. Methane breakthrough curves could be simulated by modifying a one-dimensional advection-dispersion transport model to include a Michaelis-Menten-based consumption term for methane oxidation. The K m values for methane oxidation that gave the best match for the breakthrough curve peaks were 6.0 and 9.0 μM for the uncontaminated and contaminated sites, respectively. Natural-gradient tracer tests are a promising approach for assessing microbial processes and for testing in situ bioremediation potential in groundwater systems

Transient Seepage for Levee Engineering Analyses

Science.gov (United States)

Tracy, F. T.

2017-12-01

Historically, steady-state seepage analyses have been a key tool for designing levees by practicing engineers. However, with the advances in computer modeling, transient seepage analysis has become a potentially viable tool. A complication is that the levees usually have partially saturated flow, and this is significantly more complicated in transient flow. This poster illustrates four elements of our research in partially saturated flow relating to the use of transient seepage for levee design: (1) a comparison of results from SEEP2D, SEEP/W, and SLIDE for a generic levee cross section common to the southeastern United States; (2) the results of a sensitivity study of varying saturated hydraulic conductivity, the volumetric water content function (as represented by van Genuchten), and volumetric compressibility; (3) a comparison of when soils do and do not exhibit hysteresis, and (4) a description of proper and improper use of transient seepage in levee design. The variables considered for the sensitivity and hysteresis studies are pore pressure beneath the confining layer at the toe, the flow rate through the levee system, and a levee saturation coefficient varying between 0 and 1. Getting results for SEEP2D, SEEP/W, and SLIDE to match proved more difficult than expected. After some effort, the results matched reasonably well. Differences in results were caused by various factors, including bugs, different finite element meshes, different numerical formulations of the system of nonlinear equations to be solved, and differences in convergence criteria. Varying volumetric compressibility affected the above test variables the most. The levee saturation coefficient was most affected by the use of hysteresis. The improper use of pore pressures from a transient finite element seepage solution imported into a slope stability computation was found to be the most grievous mistake in using transient seepage in the design of levees.

Transient ischemic attack presenting in an elderly patient with transient ophthalmic manifestations

Directory of Open Access Journals (Sweden)

Sparshi Jain

2016-01-01

Full Text Available Transient ischemic attack (TIA is a transient neurological deficit of cerebrovascular origin without infarction which may last only for a short period and can have varying presentations. We report a case of 58-year-old male with presenting features of sudden onset transient vertical diplopia and transient rotatory nystagmus which self-resolved within 12 h. Patient had no history of any systemic illness. On investigating, hematological investigations and neuroimaging could not explain these sudden and transient findings. A TIA could possibly explain these sudden and transient ocular findings in our patient. This case report aims to highlight the importance of TIA for ophthalmologists. We must not ignore these findings as these could be warning signs of an impending stroke which may or may not be detected on neuroimaging. Thus, early recognition, primary prevention strategies, and timely intervention are needed.

Transient simulation for a real-time operator advisor expert system

International Nuclear Information System (INIS)

Jakubowski, T.; Hajek, B.K.; Miller, D.W.; Bhatnagar, R.

1990-01-01

An Operator Advisor (OA) consisting of four integrated expert systems has been under development at The Ohio State University since 1985. The OA, designed for a General Electric BWR-6 plant, has used the Perry Nuclear Power Plants full scope simulator near Cleveland, Ohio (USA) as the reference plant. The primary goal of this development has been to provide a single system which not only performs monitoring and diagnosis functions, but also provides fault mitigation procedures to the operator, monitors the performance of these procedures and provides backup procudures should the initial ones fail. To test the system off line, a transient event simulation methodology has been developed. The simulator employs event scenarios from the Perry simulator. Scenarios are selected to test both inter- and intra-modular system behavior and response and to verify the consistency and accuracy of the knowledge base. This paper describes the OA architecture and design and the transient simulation. A discussion of a sample scenario test, including the rationale for scenario selection, is included as an example. The results of the testing demonstrate the value of off line transient simulations in that they verify system operation and help to identify characteristics requiring further improvements

MELCOR modeling of the PBF [Power Burst Facility] Severe Fuel Damage Test 1-4

International Nuclear Information System (INIS)

Madni, I.K.

1990-01-01

This paper describes a MELCOR Version 1.8 simulation of the Power Burst Facility (PBF) Severe Fuel Damage (SFD) Test 1--4. The input data for the analysis were obtained from the Test Results Report and from SCDAP/RELAP5 input. Results are presented for the transient liquid level in the test bundle, clad temperatures, shroud temperatures, clad oxidation and hydrogen generation, bundle geometry changes, fission product release, and heat transfer to the bypass flow. Comparisons are made with experimental data and with SCDAP/RELAP5 calculations. 10 refs., 7 figs

Pulse radiolysis study of one electron oxidation of riboflavin

International Nuclear Information System (INIS)

Kishore, K.; Moorthy, P.N.; Guha, S.N.

1991-01-01

One electron oxidation of riboflavin (Rf) has been studied using various oxidising species such as Cl 2 -. , SO 4 -. and OH radicals. The transient species produced by the reaction of SO 4 -. with riboflavin gave spectra with λ m at 680 and 640 nm at pHs 4 and 7.1 respectively with a pK a at ∼ 6. Cl 2 -. radicals reacted with riboflavin to give a transient spectrum with λ m at 570 nm. The possibility of two sites viz. C-8 methyl group and the extended π-ring system of the molecule for oxidation reaction are discussed. The reaction of Cl 2 -. with riboflavin is an equilibrium from which the redox potential for the Rf +. /Rf couple has been evaluated to be 2.28 V vs NHE. OH radicals reacted with riboflavin to give a transient spectrum attributable to a mixture of species produced by addition or abstraction reactions. (author)

Transient analyzer

International Nuclear Information System (INIS)

Muir, M.D.

1975-01-01

The design and design philosophy of a high performance, extremely versatile transient analyzer is described. This sub-system was designed to be controlled through the data acquisition computer system which allows hands off operation. Thus it may be placed on the experiment side of the high voltage safety break between the experimental device and the control room. This analyzer provides control features which are extremely useful for data acquisition from PPPL diagnostics. These include dynamic sample rate changing, which may be intermixed with multiple post trigger operations with variable length blocks using normal, peak to peak or integrate modes. Included in the discussion are general remarks on the advantages of adding intelligence to transient analyzers, a detailed description of the characteristics of the PPPL transient analyzer, a description of the hardware, firmware, control language and operation of the PPPL transient analyzer, and general remarks on future trends in this type of instrumentation both at PPPL and in general

Materials and processing approaches for foundry-compatible transient electronics

Science.gov (United States)

Chang, Jan-Kai; Fang, Hui; Bower, Christopher A.; Song, Enming; Yu, Xinge; Rogers, John A.

2017-07-01

Foundry-based routes to transient silicon electronic devices have the potential to serve as the manufacturing basis for “green” electronic devices, biodegradable implants, hardware secure data storage systems, and unrecoverable remote devices. This article introduces materials and processing approaches that enable state-of-the-art silicon complementary metal-oxide-semiconductor (CMOS) foundries to be leveraged for high-performance, water-soluble forms of electronics. The key elements are (i) collections of biodegradable electronic materials (e.g., silicon, tungsten, silicon nitride, silicon dioxide) and device architectures that are compatible with manufacturing procedures currently used in the integrated circuit industry, (ii) release schemes and transfer printing methods for integration of multiple ultrathin components formed in this way onto biodegradable polymer substrates, and (iii) planarization and metallization techniques to yield interconnected and fully functional systems. Various CMOS devices and circuit elements created in this fashion and detailed measurements of their electrical characteristics highlight the capabilities. Accelerated dissolution studies in aqueous environments reveal the chemical kinetics associated with the underlying transient behaviors. The results demonstrate the technical feasibility for using foundry-based routes to sophisticated forms of transient electronic devices, with functional capabilities and cost structures that could support diverse applications in the biomedical, military, industrial, and consumer industries.

Bright PanSTARRS Nuclear Transients – what are they?

Directory of Open Access Journals (Sweden)

Smartt S.

2012-12-01

Full Text Available We present an initial analysis of 49 bright transients occurring in the nuclei of galaxies with no previous known Active Galactic Nucleus (AGN. They have been discovered as part of the PanSTARRs 3π survey, and followed up with the Liverpool Telescope. Based on colours, light curve shape, and a small number with optical spectra, these transients seem to fall into three groups. Red/fast transients are nuclear supernovae of various types. Some bright nuclear transients are blue and decay on a timescale of a few months; these may be candidates for tidal disruption events. However most of the events we have found are blue and are either still rising or decaying slowly, on a timescale of years; the few spectra we have show AGN at z ∼ 1. We argue that these transients are background AGN microlensed by stars in foreground galaxies by a factor 10–100. Monitoring such events gives us very promising prospects for measuring the structure of AGN and so testing current theories.

Oxidation reactions of bilirubin in aqueous solutions

International Nuclear Information System (INIS)

Mohan, Hari; Gopinathan, C.

1990-01-01

The radical cation of bilirubin (BR) has been tentatively identified as a transient intermediate in the reactions of BR with different oxidizing species such as Br 2 - , I 2 - and CH 3 I . OH. The rate constants for these reactions have been determined as 2.4 x 10 9 , l.0 x 10 9 and 2.7 x 10 9 dm 3 mol -1 s -1 , respectively. Biliverdin is likely to be among the stable products formed on oxidation of BR by these oxidizing species. (author)

Peach Bottom Turbine Trip Simulations with RETRAN Using INER/TPC BWR Transient Analysis Method

International Nuclear Information System (INIS)

Kao Lainsu; Chiang, Show-Chyuan

2005-01-01

The work described in this paper is benchmark calculations of pressurization transient turbine trip tests performed at the Peach Bottom boiling water reactor (BWR). It is part of an overall effort in providing qualification basis for the INER/TPC BWR transient analysis method developed for the Kuosheng and Chinshan plants. The method primarily utilizes an advanced system thermal hydraulics code, RETRAN02/MOD5, for transient safety analyses. Since pressurization transients would result in a strong coupling effect between core neutronic and system thermal hydraulics responses, the INER/TPC method employs the one-dimensional kinetic model in RETRAN with a cross-section data library generated by the Studsvik-CMS code package for the transient calculations. The Peach Bottom Turbine Trip (PBTT) tests, including TT1, TT2, and TT3, have been successfully performed in the plant and assigned as standards commonly for licensing method qualifications for years. It is an essential requirement for licensing purposes to verify integral capabilities and accuracies of the codes and models of the INER/TPC method in simulating such pressurization transients. Specific Peach Bottom plant models, including both neutronics and thermal hydraulics, are developed using modeling approaches and experiences generally adopted in the INER/TPC method. Important model assumptions in RETRAN for the PBTT test simulations are described in this paper. Simulation calculations are performed with best-estimated initial and boundary conditions obtained from plant test measurements. The calculation results presented in this paper demonstrate that the INER/TPC method is capable of calculating accurately the core and system transient behaviors of the tests. Excellent agreement, both in trends and magnitudes between the RETRAN calculation results and the PBTT measurements, shows reliable qualifications of the codes/users/models involved in the method. The RETRAN calculated peak neutron fluxes of the PBTT

Analysis, by Relap5 code, of boron dilution phenomena in a Small Break Loca Transient, performed in PKL III E 2.2 test

International Nuclear Information System (INIS)

Rizzo, G.; Vella, G.

2007-01-01

The present work is finalized to investigate the E2.2 thermal-hydraulics transient of the PKL III facility, which is a scaled reproduction of a typical German PWR, operated by FRAMATOME-ANP in Erlangen, Germany, within the framework of an international cooperation (OECD/SETH project). The main purpose of the project is to study boron dilution events in Pressurized Water Reactors and to contribute to the assessment of thermal-hydraulic system codes like Relap5. The experimental test PKL III E2.2 investigates the behavior of a typical PWR after a Small Break Loss Of Coolant Accident (SB-LOCA) in a cold leg and an immediate injection of borated water in two cold legs. The main purpose of this work is to simulate the PKL III test facility and particularly its experimental transient by Relap5 system code. The adopted nodalization, already available at Department of Nuclear Engineering (DIN), has been reviewed and applied with an accurate analysis of the experimental test parameters. The main result relies in a good agreement of calculated data with experimental measures for a number of main important variables. (author)

Transient Simulation of the Multi-SERTTA Experiment with MAMMOTH

Energy Technology Data Exchange (ETDEWEB)

Ortensi, Javier [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baker, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Yaqi [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schunert, Sebastian [Idaho National Lab. (INL), Idaho Falls, ID (United States); deHart, Mark [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-07-11

This work details the MAMMOTH reactor physics simulations of the Static Environment Rodlet Transient Test Apparatus (SERTTA) conducted at Idaho National Laboratory in FY-2017. TREAT static-environment experiment vehicles are being developed to enable transient testing of Pressurized Water Reactor (PWR) type fuel specimens, including fuel concepts with enhanced accident tolerance (Accident Tolerant Fuels, ATF). The MAMMOTH simulations include point reactor kinetics as well as spatial dynamics for a temperature-limited transient. The strongly coupled multi-physics solutions of the neutron flux and temperature fields are second order accurate both in the spatial and temporal domains. MAMMOTH produces pellet stack powers that are within 1.5% of the Monte Carlo reference solutions. Some discrepancies between the MCNP model used in the design of the flux collars and the Serpent/MAMMOTH models lead to higher power and energy deposition values in Multi-SERTTA unit 1. The TREAT core results compare well with the safety case computed with point reactor kinetics in RELAP5-3D. The reactor period is 44 msec, which corresponds to a reactivity insertion of 2.685% delta k/k$. The peak core power in the spatial dynamics simulation is 431 MW, which the point kinetics model over-predicts by 12%. The pulse width at half the maximum power is 0.177 sec. Subtle transient effects are apparent at the beginning insertion in the experimental samples due to the control rod removal. Additional difference due to transient effects are observed in the sample powers and enthalpy. The time dependence of the power coupling factor (PCF) is calculated for the various fuel stacks of the Multi-SERTTA vehicle. Sample temperatures in excess of 3100 K, the melting point UO$_2$, are computed with the adiabatic heat transfer model. The planned shaped-transient might introduce additional effects that cannot be predicted with PRK models. Future modeling will be focused on the shaped-transient by improving the

Transient Simulation of the Multi-SERTTA Experiment with MAMMOTH

International Nuclear Information System (INIS)

Ortensi, Javier; Baker, Benjamin; Wang, Yaqi; Schunert, Sebastian; DeHart, Mark

2017-01-01

This work details the MAMMOTH reactor physics simulations of the Static Environment Rodlet Transient Test Apparatus (SERTTA) conducted at Idaho National Laboratory in FY-2017. TREAT static-environment experiment vehicles are being developed to enable transient testing of Pressurized Water Reactor (PWR) type fuel specimens, including fuel concepts with enhanced accident tolerance (Accident Tolerant Fuels, ATF). The MAMMOTH simulations include point reactor kinetics as well as spatial dynamics for a temperature-limited transient. The strongly coupled multi-physics solutions of the neutron flux and temperature fields are second order accurate both in the spatial and temporal domains. MAMMOTH produces pellet stack powers that are within 1.5% of the Monte Carlo reference solutions. Some discrepancies between the MCNP model used in the design of the flux collars and the Serpent/MAMMOTH models lead to higher power and energy deposition values in Multi-SERTTA unit 1. The TREAT core results compare well with the safety case computed with point reactor kinetics in RELAP5-3D. The reactor period is 44 msec, which corresponds to a reactivity insertion of 2.685% delta k/k$. The peak core power in the spatial dynamics simulation is 431 MW, which the point kinetics model over-predicts by 12%. The pulse width at half the maximum power is 0.177 sec. Subtle transient effects are apparent at the beginning insertion in the experimental samples due to the control rod removal. Additional difference due to transient effects are observed in the sample powers and enthalpy. The time dependence of the power coupling factor (PCF) is calculated for the various fuel stacks of the Multi-SERTTA vehicle. Sample temperatures in excess of 3100 K, the melting point UO$ 2 $, are computed with the adiabatic heat transfer model. The planned shaped-transient might introduce additional effects that cannot be predicted with PRK models. Future modeling will be focused on the shaped-transient by improving the

Transient electromagnetic analysis in tokamaks using TYPHOON code

International Nuclear Information System (INIS)

Belov, A.V.; Duke, A.E.; Korolkov, M.D.; Kotov, V.L.; Kukhtin, V.P.; Lamzin, E.A.; Sytchevsky, S.E.

1996-01-01

The transient electromagnetic analysis of conducting structures in tokamaks is presented. This analysis is based on a three-dimensional thin conducting shell model. The finite element method has been used to solve the corresponding integrodifferential equation. The code TYPHOON has been developed to calculate transient processes in tokamaks. Calculation tests and the code verification have been carried out. The calculation results of eddy current and force distibution and a.c. losses for different construction elements for both ITER and TEXTOR tokamaks magnetic systems are presented. (orig.)

PC operated acoustic transient spectroscopy of deep levels in MIS structures

International Nuclear Information System (INIS)

Bury, P.; Jamnicky, I.

1996-01-01

A new version of acoustic deep-level transient spectroscopy is presented to study the traps at the insulator-semiconductor interface. The acoustic deep-level transient spectroscopy uses an acoustoelectric response signal produced by the MIS structure interface when a longitudinal acoustic wave propagates through a structure. The acoustoelectric response signal is extremely sensitive to external conditions of the structure and reflects any changes in the charge distribution, connected also with charged traps. In comparison with previous version of acoustic deep-level transient spectroscopy that closely coincides with the principle of the original deep-level transient spectroscopy technique, the present technique is based on the computer-evaluated isothermal transients and represents an improved, more efficient and time saving technique. Many tests on the software used for calculation as well as on experimental setup have been performed. The improved acoustic deep-level transient spectroscopy method has been applied for the Si(p) MIS structures. The deep-level parameters as activation energy and capture cross-section have been determined. (authors)

Investigating the impact of in-vehicle transients on diesel soot emissions

Directory of Open Access Journals (Sweden)

Filipi Zoran

2008-01-01

Full Text Available This paper describes development of a test cell setup for concurrent running of a real engine and a simulation of the vehicle system, and its use for investigating highly-dynamic engine-in-vehicle operation and its effect on diesel engine emissions. Running an engine in the test cell under conditions experienced in the vehicle enables acquiring detailed insight into dynamic interactions between power train sub-systems, and the impact of it on fuel consumption and transient emissions. This type of data may otherwise be difficult and extremely costly to obtain from a vehicle prototype test. In particular, engine system response during critical transients and the effect of transient excursions on emissions are investigated using advanced, fast-response test instrumentation and emissions analyzers. Main enablers of the work include the highly dynamic AC electric dynamometer with the accompanying computerized control system and the computationally efficient simulation of the driveline/vehicle system. The latter is developed through systematic energy-based proper modeling that tailors the virtual model to capture critical powertrain transients while running in real time. Coupling the real engine with the virtual driveline/vehicle offers a chance to easily modify vehicle parameters, and even study different power train configurations. In particular, the paper describes the engine-in-the-loop study of a V-8, 6l engine coupled to a virtual 4´4 off road vehicle. This engine is considered as a high-performance option for this truck and the real prototype of the complete vehicle does not exist yet. The results shed light on critical transients in a conventional powertrain and their effect on NOx and soot emissions. Measurements demonstrate very large spikes of particulate concentration at the initiation of vehicle acceleration events. Characterization of transients and their effect on particulate emission provides a basis for devising engine-level or

Transient characteristics of parallel running of the 20kVA superconducting synchronous generator and a conventional one

International Nuclear Information System (INIS)

Nitta, T.; Okada, T.

1989-01-01

This paper describes electrical transient characteristics of parallel running of the 20kVA superconducting synchronous generator and a conventional one. In the experimental power system, the superconducting generator is connected through reactors (artificial transmission lines) to a regional power system (infinite bus) and the conventional generator (20kVA) is connected to the terminal of the superconducting generator. Several tests were performed in order to consider the transient behavior of superconducting generator (SCG) in the power system. The items of the tests are synchronous closing test, loss of synchronism test and disconnecting and reclosing test. From the experimental results, it can be said that by installing SCG in power systems, voltage stability and power system stability can be improved in transient states as well as in steady states and the variation of armature current of SCG during a transient period is extremely larger than that of the conventional one. The transient analysis by a computer simulation was also carried out for the experiments. The simulation results are in good agreement with the experimental ones

Considerations in Execution of High Temperature Steam Oxidation Testing

Energy Technology Data Exchange (ETDEWEB)

Nelson, Andrew T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-04-01

The Fuel Cycle Research and Development program’s Advanced Fuels Campaign is currently supporting a range of experimental efforts aimed at development and qualification of so-called ‘accident tolerant’ nuclear fuel forms. Numerous criteria have been developed by which proposed systems will be investigated; foremost among these will be their resistance to oxidation at high temperatures by steamdominated atmospheres. Experimental characterization of the various proposed systems is currently ongoing at numerous national laboratories as well as at industrial and university partners using a wide range of different laboratory equipment and techniques. This requires consideration of differences that may develop among test protocols due to both intrinsic (e.g. differences between experimental capabilities) and extrinsic (e.g. methodology of test execution) factors. These are essential to understand to provide confidence across institutions in the data collected if it is used to justify resources for further investigation. The focus of this document is to provide an initial discussion of factors that may play a role in governing the observed oxidation of a test sample. It will remain up to the principle investigator to judge whether a specific factor discussed is directly applicable to the system under investigation. The purpose of the specific experiment must also guide determination of whether a given factor requires careful consideration or not.

SCANAIR: A transient fuel performance code

International Nuclear Information System (INIS)

Moal, Alain; Georgenthum, Vincent; Marchand, Olivier

2014-01-01

Highlights: • Since the early 1990s, the code SCANAIR is developed at IRSN. • The software focuses on studying fast transients such as RIA in light water reactors. • The fuel rod modelling is based on a 1.5D approach. • Thermal and thermal-hydraulics, mechanical and gas behaviour resolutions are coupled. • The code is used for safety assessment and integral tests analysis. - Abstract: Since the early 1990s, the French “Institut de Radioprotection et de Sûreté Nucléaire” (IRSN) has developed the SCANAIR computer code with the view to analysing pressurised water reactor (PWR) safety. This software specifically focuses on studying fast transients such as reactivity-initiated accidents (RIA) caused by possible ejection of control rods. The code aims at improving the global understanding of the physical mechanisms governing the thermal-mechanical behaviour of a single rod. It is currently used to analyse integral tests performed in CABRI and NSRR experimental reactors. The resulting validated code is used to carry out studies required to evaluate margins in relation to criteria for different types of fuel rods used in nuclear power plants. Because phenomena occurring during fast power transients are complex, the simulation in SCANAIR is based on a close coupling between several modules aimed at modelling thermal, thermal-hydraulics, mechanical and gas behaviour. During the first stage of fast power transients, clad deformation is mainly governed by the pellet–clad mechanical interaction (PCMI). At the later stage, heat transfers from pellet to clad bring the cladding material to such high temperatures that the boiling crisis might occurs. The significant over-pressurisation of the rod and the fact of maintaining the cladding material at elevated temperatures during a fairly long period can lead to ballooning and possible clad failure. A brief introduction describes the context, the historical background and recalls the main phenomena involved under

SCANAIR: A transient fuel performance code

Energy Technology Data Exchange (ETDEWEB)

Moal, Alain, E-mail: alain.moal@irsn.fr; Georgenthum, Vincent; Marchand, Olivier

2014-12-15

Highlights: • Since the early 1990s, the code SCANAIR is developed at IRSN. • The software focuses on studying fast transients such as RIA in light water reactors. • The fuel rod modelling is based on a 1.5D approach. • Thermal and thermal-hydraulics, mechanical and gas behaviour resolutions are coupled. • The code is used for safety assessment and integral tests analysis. - Abstract: Since the early 1990s, the French “Institut de Radioprotection et de Sûreté Nucléaire” (IRSN) has developed the SCANAIR computer code with the view to analysing pressurised water reactor (PWR) safety. This software specifically focuses on studying fast transients such as reactivity-initiated accidents (RIA) caused by possible ejection of control rods. The code aims at improving the global understanding of the physical mechanisms governing the thermal-mechanical behaviour of a single rod. It is currently used to analyse integral tests performed in CABRI and NSRR experimental reactors. The resulting validated code is used to carry out studies required to evaluate margins in relation to criteria for different types of fuel rods used in nuclear power plants. Because phenomena occurring during fast power transients are complex, the simulation in SCANAIR is based on a close coupling between several modules aimed at modelling thermal, thermal-hydraulics, mechanical and gas behaviour. During the first stage of fast power transients, clad deformation is mainly governed by the pellet–clad mechanical interaction (PCMI). At the later stage, heat transfers from pellet to clad bring the cladding material to such high temperatures that the boiling crisis might occurs. The significant over-pressurisation of the rod and the fact of maintaining the cladding material at elevated temperatures during a fairly long period can lead to ballooning and possible clad failure. A brief introduction describes the context, the historical background and recalls the main phenomena involved under

Transient drainage summary report

International Nuclear Information System (INIS)

1996-09-01

This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage

TRANSIENT ELECTRONICS CATEGORIZATION

Science.gov (United States)

2017-08-24

AFRL-RY-WP-TR-2017-0169 TRANSIENT ELECTRONICS CATEGORIZATION Dr. Burhan Bayraktaroglu Devices for Sensing Branch Aerospace Components & Subsystems...SUBTITLE TRANSIENT ELECTRONICS CATEGORIZATION 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) Dr. Burhan...88ABW-2017-3747, Clearance Date 31 July 2017. Paper contains color. 14. ABSTRACT Transient electronics is an emerging technology area that lacks proper

Mechanical test of E110 cladding material oxidized in hydrogen rich steam atmosphere

International Nuclear Information System (INIS)

Windberg, P.; Perez-Fero, E.

2005-01-01

The behavior of the fuel cladding under accidental conditions has been studied at the AEKI for more than a decade. Earlier, the effect of oxygen and hydrogen content on the mechanical properties was studied separately. The present experiments can help to understand what kind of processes took place in the cleaning tank at Paks NPP (2003). The purpose of our experiments was to investigate high temperature oxidation of E110 cladding in steam + hydrogen mixture. A high temperature tube furnace was used for oxidation of the samples. The oxidation was carried out at three different temperatures (900 0 C, 1000 0 C, 1100 0 C). The hydrogen content in the steam was varied between 19-36 vol%. The oxygen content of the sample was defined as oxidation ratio. Two sizes (length: 2 and 8 mm) of cladding rings and 100 mm long E110 cladding tubes were oxidized. After the oxidation we made compression and tensile tests for rings, and ballooning experiments for 100 mm long tube. The most important conclusions were the following. Oxidation in H-rich steam atmosphere need longer time to get the same oxidation ratio compared to the steam oxidation without hydrogen. The shorter oxidation time results in a more compact oxide layer. The longer oxidation time leads to a cracked oxide layer. (author)

Transient chaos in a globally coupled system of nearly conservative Hamiltonian Duffing oscillators

International Nuclear Information System (INIS)

Sabarathinam, S.; Thamilmaran, K.

2015-01-01

Highlights: •We have examined transient chaos in globally coupled oscillators. •We analyze transient chaos using new techniques. •We give experimental confirmation of transient chaos. -- Abstract: In this work, transient chaos in a ring and globally coupled system of nearly conservative Hamiltonian Duffing oscillators is reported. The networks are formed by coupling of three, four and six Duffing oscillators. The nearly conservative Hamiltonian nature of the coupled system is proved by stability analysis. The transient phenomenon is confirmed through various numerical investigations such as recurrence analysis, 0–1 test and Finite Time Lyapunov Exponents. Further, the effect of damping and the average transient lifetime of three, four and six coupled schemes for randomly generated initial conditions have been analyzed. The experimental confirmation of transient chaos in an illustrative system of three ringly coupled Duffing oscillators is also presented

CHF during flow rate, pressure and power transients in heated channels

International Nuclear Information System (INIS)

Celata, G.P.; Cumo, M.

1987-01-01

The behaviour of forced two-phase flows following inlet flow rate, pressure and power transients is presented here with reference to experiments performed with a R-12 loop. A circular duct, vertical test section (L = 2300 mm; D = 7.5 mm) instrumented with fluid (six) and wall (twelve) thermocouples has been employed. Transients have been carried out performing several values of flow decays (exponential decrease), depressurization rates (exponential decrease) and power inputs (step-wise increase). Experimental data have shown the complete inadequacy of steady-state critical heat flux correlations in predicting the onset of boiling crisis during fast transients. Data analysis for a better theoretical prediction of CHF occurrence during transient conditions has been accomplished, and design correlations for critical heat flux and time-to-crisis predictions have been proposed for the different types of transients

PSB-VVER simulation of Kozloduy NPP 'loss of feed water transient'

Energy Technology Data Exchange (ETDEWEB)

Groudev, P.P. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: pavlinpg@inrne.bas.bg; Stefanova, A.E. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: antoanet@inrne.bas.bg; Gencheva, R.V. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: roseh@inrne.bas.bg; Pavlova, M.P. [Institute for Nuclear Research and Nuclear Energy, Tzarigradsko Shaussee 72, Sofia 1784 (Bulgaria)]. E-mail: pavlova@inrne.bas.bg

2005-04-01

This paper provides a comparison between the PSB test facility experimental results obtained during the simulation of loss of feed water transient (LOFW) and the calculation results received by INRNE computer model of the same test facility. Integral thermal-hydraulic PSB-VVER test facility located at Electrogorsk Research and Engineering Center on NPPs Safety (EREC) was put in operation in 1998. The structure of the test facility allows experimental studies under steady state, transient and accident conditions. RELAP5/MOD3.2 computer code has been used to simulate the loss of feed water transient in a PSB-VVER model. This model was developed at the Institute for Nuclear Research and Nuclear Energy for simulation of loss of feed water transient. The objective of the experiment 'loss of feed water', which has been performed at PSB-VVER test facility is simulation of Kozloduy NPP LOFW transient. One of the main requirements to the experiment scenario has been to reproduce all main events and phenomena that occurred in Kozloduy NPP during the LOFW transient. Analyzing the PSB-VVER test with a RELAP5/MOD3.2 computer code as a standard problem allows investigating the phenomena included in the VVER code validation matrix as 'integral system effects' and 'natural circulation'. For assessment of the RELAP5 capability to predict the 'Integral system effect' phenomenon the following RELAP5 quantities are compared with external trends: the primary pressure and the hot and cold leg temperatures. In order to assess the RELAP5 capability to predict the 'Natural circulation' phenomenon the hot and cold leg temperatures behavior have been investigated. This report was possible through the participation of leading specialists from Kozloduy NPP and with the support of Argonne National Laboratory (ANL), under the International Nuclear Safety Program (INSP) of the United States Department of Energy.

Application of statistical method for FBR plant transient computation

International Nuclear Information System (INIS)

Kikuchi, Norihiro; Mochizuki, Hiroyasu

2014-01-01

Highlights: • A statistical method with a large trial number up to 10,000 is applied to the plant system analysis. • A turbine trip test conducted at the “Monju” reactor is selected as a plant transient. • A reduction method of trial numbers is discussed. • The result with reduced trial number can express the base regions of the computed distribution. -- Abstract: It is obvious that design tolerances, errors included in operation, and statistical errors in empirical correlations effect on the transient behavior. The purpose of the present study is to apply above mentioned statistical errors to a plant system computation in order to evaluate the statistical distribution contained in the transient evolution. A selected computation case is the turbine trip test conducted at 40% electric power of the prototype fast reactor “Monju”. All of the heat transport systems of “Monju” are modeled with the NETFLOW++ system code which has been validated using the plant transient tests of the experimental fast reactor Joyo, and “Monju”. The effects of parameters on upper plenum temperature are confirmed by sensitivity analyses, and dominant parameters are chosen. The statistical errors are applied to each computation deck by using a pseudorandom number and the Monte-Carlo method. The dSFMT (Double precision SIMD-oriented Fast Mersenne Twister) that is developed version of Mersenne Twister (MT), is adopted as the pseudorandom number generator. In the present study, uniform random numbers are generated by dSFMT, and these random numbers are transformed to the normal distribution by the Box–Muller method. Ten thousands of different computations are performed at once. In every computation case, the steady calculation is performed for 12,000 s, and transient calculation is performed for 4000 s. In the purpose of the present statistical computation, it is important that the base regions of distribution functions should be calculated precisely. A large number of

Transient analysis of a variable speed rotary compressor

International Nuclear Information System (INIS)

Park, Youn Cheol

2010-01-01

A transient simulation model of a rolling piston type rotary compressor is developed to predict the dynamic characteristics of a variable speed compressor. The model is based on the principles of conservation, real gas equations, kinematics of the crankshaft and roller, mass flow loss due to leakage, and heat transfer. For the computer simulation of the compressor, the experimental data were obtained from motor performance tests at various operating frequencies. Using the developed model, re-expansion loss, friction loss, mass flow loss and heat transfer loss is estimated as a function of the crankshaft speed in a variable speed compressor. In addition, the compressor efficiency and energy losses are predicted at various compressor-operating frequencies. Since the transient state of the compressor strongly depends on the system, the developed model is combined with a transient system simulation program to get transient variations of the compression process in the system. Motor efficiency, mechanical efficiency, motor torque and volumetric efficiency are calculated with respect to variation of the driving frequency in a rotary compressor.

FIX-II/2032, BWR Pump Trip Experiment 2032, Simulation Mass Flow and Power Transients

International Nuclear Information System (INIS)

1988-01-01

1 - Description of test facility: In the FIX-II pump trip experiments, mass flow and power transients were simulated subsequent to a total loss of power to the recirculation pumps in an internal pump boiling water reactor. The aim was to determine the initial power limit to give dryout in the fuel bundle for the specified transient. In addition, the peak cladding temperature was measured and the rewetting was studied. 2 - Description of test: Pump trip experiment 2032 was a part of test group 2, i.e. the mass flow transient was to simulate the pump coast down with a pump inertia of 11.3 kg.m -2 . The initial power in the 36-rod bundle was 4.44 MW which gave dryout after 1.4 s from the start of the flow transient. A maximum rod cladding temperature of 457 degrees C was measured. Rewetting was obtained after 7.6 s. 3 - Experimental limitations or shortcomings: No ECCS injection systems

Effects of transients in LIGO suspensions on searches for gravitational waves.

Science.gov (United States)

Walker, M; Abbott, T D; Aston, S M; González, G; Macleod, D M; McIver, J; Abbott, B P; Abbott, R; Adams, C; Adhikari, R X; Anderson, S B; Ananyeva, A; Appert, S; Arai, K; Ballmer, S W; Barker, D; Barr, B; Barsotti, L; Bartlett, J; Bartos, I; Batch, J C; Bell, A S; Betzwieser, J; Billingsley, G; Birch, J; Biscans, S; Biwer, C; Blair, C D; Bork, R; Brooks, A F; Ciani, G; Clara, F; Countryman, S T; Cowart, M J; Coyne, D C; Cumming, A; Cunningham, L; Danzmann, K; Da Silva Costa, C F; Daw, E J; DeBra, D; DeRosa, R T; DeSalvo, R; Dooley, K L; Doravari, S; Driggers, J C; Dwyer, S E; Effler, A; Etzel, T; Evans, M; Evans, T M; Factourovich, M; Fair, H; Fernández Galiana, A; Fisher, R P; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Giaime, J A; Giardina, K D; Goetz, E; Goetz, R; Gras, S; Gray, C; Grote, H; Gushwa, K E; Gustafson, E K; Gustafson, R; Hall, E D; Hammond, G; Hanks, J; Hanson, J; Hardwick, T; Harry, G M; Heintze, M C; Heptonstall, A W; Hough, J; Izumi, K; Jones, R; Kandhasamy, S; Karki, S; Kasprzack, M; Kaufer, S; Kawabe, K; Kijbunchoo, N; King, E J; King, P J; Kissel, J S; Korth, W Z; Kuehn, G; Landry, M; Lantz, B; Lockerbie, N A; Lormand, M; Lundgren, A P; MacInnis, M; Márka, S; Márka, Z; Markosyan, A S; Maros, E; Martin, I W; Martynov, D V; Mason, K; Massinger, T J; Matichard, F; Mavalvala, N; McCarthy, R; McClelland, D E; McCormick, S; McIntyre, G; Mendell, G; Merilh, E L; Meyers, P M; Miller, J; Mittleman, R; Moreno, G; Mueller, G; Mullavey, A; Munch, J; Nuttall, L K; Oberling, J; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; Ottaway, D J; Overmier, H; Palamos, J R; Paris, H R; Parker, W; Pele, A; Penn, S; Phelps, M; Pierro, V; Pinto, I; Principe, M; Prokhorov, L G; Puncken, O; Quetschke, V; Quintero, E A; Raab, F J; Radkins, H; Raffai, P; Reid, S; Reitze, D H; Robertson, N A; Rollins, J G; Roma, V J; Romie, J H; Rowan, S; Ryan, K; Sadecki, T; Sanchez, E J; Sandberg, V; Savage, R L; Schofield, R M S; Sellers, D; Shaddock, D A; Shaffer, T J; Shapiro, B; Shawhan, P; Shoemaker, D H; Sigg, D; Slagmolen, B J J; Smith, B; Smith, J R; Sorazu, B; Staley, A; Strain, K A; Tanner, D B; Taylor, R; Thomas, M; Thomas, P; Thorne, K A; Thrane, E; Torrie, C I; Traylor, G; Tuyenbayev, D; Vajente, G; Valdes, G; van Veggel, A A; Vecchio, A; Veitch, P J; Venkateswara, K; Vo, T; Vorvick, C; Ward, R L; Warner, J; Weaver, B; Weiss, R; Weßels, P; Willke, B; Wipf, C C; Worden, J; Wu, G; Yamamoto, H; Yancey, C C; Yu, Hang; Yu, Haocun; Zhang, L; Zucker, M E; Zweizig, J

2017-12-01

This paper presents an analysis of the transient behavior of the Advanced LIGO (Laser Interferometer Gravitational-wave Observatory) suspensions used to seismically isolate the optics. We have characterized the transients in the longitudinal motion of the quadruple suspensions during Advanced LIGO's first observing run. Propagation of transients between stages is consistent with modeled transfer functions, such that transient motion originating at the top of the suspension chain is significantly reduced in amplitude at the test mass. We find that there are transients seen by the longitudinal motion monitors of quadruple suspensions, but they are not significantly correlated with transient motion above the noise floor in the gravitational wave strain data, and therefore do not present a dominant source of background noise in the searches for transient gravitational wave signals. Using the suspension transfer functions, we compared the transients in a week of gravitational wave strain data with transients from a quadruple suspension. Of the strain transients between 10 and 60 Hz, 84% are loud enough that they would have appeared above the sensor noise in the top stage quadruple suspension monitors if they had originated at that stage at the same frequencies. We find no significant temporal correlation with the suspension transients in that stage, so we can rule out suspension motion originating at the top stage as the cause of those transients. However, only 3.2% of the gravitational wave strain transients are loud enough that they would have been seen by the second stage suspension sensors, and none of them are above the sensor noise levels of the penultimate stage. Therefore, we cannot eliminate the possibility of transient noise in the detectors originating in the intermediate stages of the suspension below the sensing noise.

Transient leak detection in crude oil pipelines

Energy Technology Data Exchange (ETDEWEB)

Beushausen, R.; Tornow, S.; Borchers, H. [Nord-West Oelleitung, Wilhelmshaven (Germany); Murphy, K.; Zhang, J. [Atmos International Ltd., Manchester (United Kingdom)

2004-07-01

Nord-West Oelleitung (NWO) operates 2 crude oil pipelines from Wilhemshaven to Koln and Hamburg respectively. German regulations for transporting flammable substances stipulate that 2 independent continuously working procedures be used to detect leaks. Leak detection pigs are used routinely to complement the surveillance system. This paper described the specific issues of transient leak detection in crude oil pipelines. It was noted that traditional methods have failed to detect leaks that occur immediately after pumps are turned on or off because the pressure wave generated by the transient dominates the pressure wave that results from the leak. Frequent operational changes in a pipeline are often accompanied by an increased number of false alarms and failure to detect leaks due to unsteady operations. NWO therefore decided to have the Atmos statistical pipeline leak detection (SPLD) system installed on their pipelines. The key to the SPLD system is the sequential probability ratio test. Comprehensive data validation is performed following reception of pipeline data from the supervisory control and data acquisition (SCADA) system. The validated data is then used to calculate the corrected flow imbalance, which is fed into the SPRT to determine if there is an increase in the flow imbalance. Pattern recognition is then used to distinguish a leak from operational changes. The SPLD is unique because it uses 3 computational pipeline monitoring methods simultaneously, namely modified volume balance, statistical analysis, and pressure and flow monitoring. The successful installation and testing of the SPLD in 2 crude oil pipelines was described along with the main difficulties associated with transient leaks. Field results were presented for both steady-state and transient conditions. 5 refs., 2 tabs., 16 figs.

Transient hyperthyroidism of hyperemesis gravidarum.

Science.gov (United States)

Tan, Jackie Y L; Loh, Keh Chuan; Yeo, George S H; Chee, Yam Cheng

2002-06-01

To characterise the clinical, biochemical and thyroid antibody profile in women with transient hyperthyroidism of hyperemesis gravidarum. Prospective observational study. Hospital inpatient gynaecological ward. Women admitted with hyperemesis gravidarum and found to have hyperthyroidism. Fifty-three women were admitted with hyperemesis gravidarum and were found to have hyperthyroidism. Each woman was examined for clinical signs of thyroid disease and underwent investigations including urea, creatinine, electrolytes, liver function test, thyroid antibody profile and serial thyroid function test until normalisation. Gestation at which thyroid function normalised, clinical and thyroid antibody profile and pregnancy outcome (birthweight, gestation at delivery and Apgar score at 5 minutes). Full data were available for 44 women. Free T4 levels normalised by 15 weeks of gestation in the 39 women with transient hyperthyroidism while TSH remained suppressed until 19 weeks of gestation. None of these women were clinically hyperthyroid. Thyroid antibodies were not found in most of them. Median birthweight in the infants of mothers who experienced weight loss of > 5% of their pre-pregnancy weight was lower compared with those of women who did not (P = 0.093). Five women were diagnosed with Graves' disease based on clinical features and thyroid antibody profile. In transient hyperthyroidism of hyperemesis gravidarum, thyroid function normalises by the middle of the second trimester without anti-thyroid treatment. Clinically overt hyperthyroidism and thyroid antibodies are usually absent. Apart from a non-significant trend towards lower birthweights in the infants of mothers who experienced significant weight loss, pregnancy outcome was generally good. Routine assessment of thyroid function is unnecessary for women with hyperemesis gravidarum in the absence of any clinical features of hyperthyroidism.

Status of test results of electrochemical organic oxidation of a tank 241-SY-101 simulated waste

International Nuclear Information System (INIS)

Colby, S.A.

1994-06-01

This report presents scoping test results of an electrochemical waste pretreatment process to oxidize organic compounds contained in the Hanford Site's radioactive waste storage tanks. Electrochemical oxidation was tested on laboratory scale to destroy organics that are thought to pose safety concerns, using a nonradioactive, simulated tank waste. Minimal development work has been applied to alkaline electrochemical organic destruction. Most electrochemical work has been directed towards acidic electrolysis, as in the metal purification industry, and silver catalyzed oxidation. Alkaline electrochemistry has traditionally been associated with the following: (1) inefficient power use, (2) electrode fouling, and (3) solids handling problems. Tests using a laboratory scale electrochemical cell oxidized surrogate organics by applying a DC electrical current to the simulated tank waste via anode and cathode electrodes. The analytical data suggest that alkaline electrolysis oxidizes the organics into inorganic carbonate and smaller carbon chain refractory organics. Electrolysis treats the waste without adding chemical reagents and at ambient conditions of temperature and pressure. Cell performance was not affected by varying operating conditions and supplemental electrolyte additions

Transient oxidation of Al-deposited Fe-Cr-Al alloy foil

International Nuclear Information System (INIS)

Andoh, A.

1997-01-01

The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas (θ-Al 2 O 3 , γ-Al 2 O 3 ). Scales consisting of θ-Al 2 O 3 and a small amount of α-Al 2 O 3 develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of θ-Al 2 O 3 and α-Al 2 O 3 grow rapidly on the Al-deposited foil. The transformation from θ-Al 2 O 3 to α-Al 2 O 3 is very fast, and the scales result in only α-Al 2 O 3 . In contrast, α-Al 2 O 3 scales containing a minor amount of FeAl 2 O 4 develop on the alloy foil. The growth rate of α-Al 2 O 3 scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.)

PSH Transient Simulation Modeling

Energy Technology Data Exchange (ETDEWEB)

Muljadi, Eduard [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-12-21

PSH Transient Simulation Modeling presentation from the WPTO FY14 - FY16 Peer Review. Transient effects are an important consideration when designing a PSH system, yet numerical techniques for hydraulic transient analysis still need improvements for adjustable-speed (AS) reversible pump-turbine applications.

Use of plant operating history to define transient loads

International Nuclear Information System (INIS)

Dwivedy, K.K.

1996-01-01

Fatigue and crack growth analyses of components subjected to transient loads have been under continuous development during the recent past to include effects of environment on the components. The accuracy of the evaluation method on the predicted reliability of the components in the operating environment has become a focus of attention. Methods have integrated available material/component test data to improve evaluation techniques. However, in the area of definition of thermal transient loads the analyst still has to remain conservative, because no realistic guidelines have been developed to define thermal transients and their sequences. Fatigue re-evaluations of components are becoming increasingly necessary in operating plants as they age due to two reasons: (1) Components show age related degradation and cannot be repaired/replaced due to economic/logistic reasons. (2) Components experience transient conditions which were not considered in the original design. In either case, the evaluation of remaining life of components involves definition of transients and their sequence from the time the component was put in service until the end of life. As a common practice, initial plant design transients are used in a conservative definition of sequences to obtain results unrealistic for the situation, which sometimes leads to inaccurate estimate of the remaining life of components. The objective of this paper is to use plant operating history and plant monitoring data to provide procedures and techniques to define realistic transients for evaluation

Modeling of oxygen gas diffusion and consumption during the oxic transient in a disposal cell of radioactive waste

International Nuclear Information System (INIS)

De Windt, Laurent; Marsal, François; Corvisier, Jérôme; Pellegrini, Delphine

2014-01-01

Highlights: • This paper deals with the geochemistry of underground HLW disposals. • The oxic transient is a key issue in performance assessment (e.g. corrosion, redox). • A reactive transport model is explicitly coupled to gas diffusion and reactivity. • Application to in situ experiment (Tournemire laboratory) and HLW disposal cell. • Extent of the oxidizing/reducing front is investigated by sensitivity analysis. - Abstract: The oxic transient in geological radioactive waste disposals is a key issue for the performance of metallic components that may undergo high corrosion rates under such conditions. A previous study carried out in situ in the argillite formation of Tournemire (France) has suggested that oxic conditions could have lasted several years. In this study, a multiphase reactive transport model is performed with the code HYTEC to analyze the balance between the kinetics of pyrite oxidative dissolution, the kinetics of carbon steel corrosion and oxygen gas diffusion when carbon steel components are emplaced in the geological medium. Two cases were modeled: firstly, the observations made in situ have been reproduced, and the model established was then applied to a disposal cell for high-level waste (HLW) in an argillaceous formation, taking into account carbon steel components and excavated damaged zones (EDZ). In a closed system, modeling leads to a complete and fast consumption of oxygen in both cases. Modeling results are more consistent with the in situ test while considering residual voids between materials and/or a water unsaturated state allowing for oxygen gas diffusion (open conditions). Under similar open conditions and considering ventilation of the handling drifts, a redox contrast occurs between reducing conditions at the back of the disposal cell (with anoxic corrosion of steel and H 2 production) and oxidizing conditions at the front of the cell (with oxic corrosion of steel). The extent of the oxidizing/reducing front in the

Exercise Increases 24-h Fat Oxidation Only When It Is Performed Before Breakfast

Directory of Open Access Journals (Sweden)

Kaito Iwayama

2015-12-01

Interpretation: Under energy-balanced conditions, 24-h fat oxidation was increased by exercise only when performed before breakfast. Transient carbohydrate deficits, i.e., glycogen depletion, observed after morning exercise may have contributed to increased 24-h fat oxidation.

Acetate transiently inhibits myocardial contraction by increasing mitochondrial calcium uptake.

Science.gov (United States)

Schooley, James F; Namboodiri, Aryan M A; Cox, Rachel T; Bünger, Rolf; Flagg, Thomas P

2014-12-09

There is a close relationship between cardiovascular disease and cardiac energy metabolism, and we have previously demonstrated that palmitate inhibits myocyte contraction by increasing Kv channel activity and decreasing the action potential duration. Glucose and long chain fatty acids are the major fuel sources supporting cardiac function; however, cardiac myocytes can utilize a variety of substrates for energy generation, and previous studies demonstrate the acetate is rapidly taken up and oxidized by the heart. In this study, we tested the effects of acetate on contractile function of isolated mouse ventricular myocytes. Acute exposure of myocytes to 10 mM sodium acetate caused a marked, but transient, decrease in systolic sarcomere shortening (1.49 ± 0.20% vs. 5.58 ± 0.49% in control), accompanied by a significant increase in diastolic sarcomere length (1.81 ± 0.01 μm vs. 1.77 ± 0.01 μm in control), with a near linear dose response in the 1-10 mM range. Unlike palmitate, acetate caused no change in action potential duration; however, acetate markedly increased mitochondrial Ca(2+) uptake. Moreover, pretreatment of cells with the mitochondrial Ca(2+) uptake blocker, Ru-360 (10 μM), markedly suppressed the effect of acetate on contraction. Lehninger and others have previously demonstrated that the anions of weak aliphatic acids such as acetate stimulate Ca(2+) uptake in isolated mitochondria. Here we show that this effect of acetate appears to extend to isolated cardiac myocytes where it transiently modulates cell contraction.

Newborn hearing screening with transient evoked otoacoustic emissions and automatic auditory brainstem response

OpenAIRE

Renata Mota Mamede de Carvallo; Carla Gentile Matas; Isabela de Souza Jardim

2008-01-01

Objective: The aim of the present investigation was to check Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests applied together in regular nurseries and Newborn Intensive Care Units (NICU), as well as to describe and compare the results obtained in both groups. Methods: We tested 150 newborns from regular nurseries and 70 from NICU. Rresults: The newborn hearing screening results using Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem...

Transient global amnesia: neuropsychological dysfunction during attack and recovery in two "pure" cases.

OpenAIRE

Regard, M; Landis, T

1984-01-01

Two patients with transient global amnesia are reported. Comprehensive neuropsychological evaluation, during the amnesic episode, as well as follow-up examinations on memory were performed. The course of the amnesia was exemplified by two comparable memory tests in different modalities. Partial retrograde amnesia and complete anterograde amnesia were demonstrated during the transient episode. Objective recovery was found to be slower than subjectively experienced, but test performance was com...

Strength of Anode‐Supported Solid Oxide Fuel Cells

DEFF Research Database (Denmark)

Faes, A.; Frandsen, Henrik Lund; Kaiser, Andreas

2011-01-01

Nickel oxide and yttria doped zirconia composite strength is crucial for anode‐supported solid oxide fuel cells, especially during transient operation, but also for the initial stacking process, where cell curvature after sintering can cause problems. This work first compares tensile and ball....... Even though the electrolyte is to the tensile side, it is found that the anode support fails due to the thermo‐mechanical residual stresses....

Comparison of pressure transient response in intensely and sparsely fractured reservoirs

Energy Technology Data Exchange (ETDEWEB)

Johns, R.T.

1989-04-01

A comprehensive analytical model is presented to study the pressure transient behavior of a naturally fractured reservoir with a continuous matrix block size distribution. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Transient interporosity flow is assumed and interporosity skin is incorporated. Drawdown and interference pressure transient tests are investigated. The results show distinctions in the pressure response from intensely and sparsely fractured reservoirs in the absence of interporosity skin. Also, uniformly and nonuniformly fractured reservoirs exhibit distinct responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block size variability, approaches a nonfractured (homogeneous) reservoir response. Type curves are developed to estimate matrix block size variability and the degree of fracture intensity from drawdown and interference well tests.

Transient stability index for online stability assessment and contingency evaluation

Energy Technology Data Exchange (ETDEWEB)

Ribbens-Pavella, M; Murthy, P G; Horward, J L; Carpentier, J L

1982-04-01

An on-line methodology is proposed for assessing the robustness of a power system from the point of view of transient stability, and a scalar expression, the transient stability index, is accordingly derived. The reliability and sensitivity of this index are tested by means of simulations for a number of power system cases. The index is shown to be appropriate for online stability assessment, contingency evaluation and preventive control. 14 refs.

Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

Science.gov (United States)

Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

2015-01-01

During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

Attenuation of Ca2+ homeostasis, oxidative stress, and mitochondrial dysfunctions in diabetic rat heart: insulin therapy or aerobic exercise?

Science.gov (United States)

da Silva, Márcia F; Natali, Antônio J; da Silva, Edson; Gomes, Gilton J; Teodoro, Bruno G; Cunha, Daise N Q; Drummond, Lucas R; Drummond, Filipe R; Moura, Anselmo G; Belfort, Felipe G; de Oliveira, Alessandro; Maldonado, Izabel R S C; Alberici, Luciane C

2015-07-15

We tested the effects of swimming training and insulin therapy, either alone or in combination, on the intracellular calcium ([Ca(2+)]i) homeostasis, oxidative stress, and mitochondrial functions in diabetic rat hearts. Male Wistar rats were separated into control, diabetic, or diabetic plus insulin groups. Type 1 diabetes mellitus was induced by streptozotocin (STZ). Insulin-treated groups received 1 to 4 UI of insulin daily for 8 wk. Each group was divided into sedentary or exercised rats. Trained groups were submitted to swimming (90 min/day, 5 days/wk, 8 wk). [Ca(2+)]i transient in left ventricular myocytes (LVM), oxidative stress in LV tissue, and mitochondrial functions in the heart were assessed. Diabetes reduced the amplitude and prolonged the times to peak and to half decay of the [Ca(2+)]i transient in LVM, increased NADPH oxidase-4 (Nox-4) expression, decreased superoxide dismutase (SOD), and increased carbonyl protein contents in LV tissue. In isolated mitochondria, diabetes increased Ca(2+) uptake, susceptibility to permeability transition pore (MPTP) opening, uncoupling protein-2 (UCP-2) expression, and oxygen consumption but reduced H2O2 release. Swimming training corrected the time course of the [Ca(2+)]i transient, UCP-2 expression, and mitochondrial Ca(2+) uptake. Insulin replacement further normalized [Ca(2+)]i transient amplitude, Nox-4 expression, and carbonyl content. Alongside these benefits, the combination of both therapies restored the LV tissue SOD and mitochondrial O2 consumption, H2O2 release, and MPTP opening. In conclusion, the combination of swimming training with insulin replacement was more effective in attenuating intracellular Ca(2+) disruptions, oxidative stress, and mitochondrial dysfunctions in STZ-induced diabetic rat hearts. Copyright © 2015 the American Physiological Society.

Transient analysis on the SMART-P anticipated transients without scram

International Nuclear Information System (INIS)

Yang, S. H.; Bae, K. H.; Kim, H. C.; Zee, S. Q.

2005-01-01

Anticipated transients without scram (ATWS) are anticipated operational occurrences accompanied by a failure of an automatic reactor trip when required. Although the occurrence probability of the ATWS events is considerably low, these events can result in unacceptable consequences, i.e. the pressurization of the reactor coolant system (RCS) up to an unacceptable range and a core-melting situation. Therefore, the regulatory body requests the installation of a protection system against the ATWS events. According to the request, a diverse protection system (DPS) is installed in the SMART-P (System-integrated Modular Advanced ReacTor-Pilot). This paper presents the results of the transient analysis performed to identify the performance of the SMART-P against the ATWS. In the analysis, the TASS/SMR (Transients And Setpoint Simulation/Small and Medium Reactor) code is applied to identify the thermal hydraulic response of the RCS during the transients

Description and characterization of the ACRR's programmable transient rod withdrawal mode

International Nuclear Information System (INIS)

Boldt, K.R.; Sullivan, W.H.; Kefauver, H.L.

1980-01-01

To satisfy experiment needs for Sandia's Advanced Reactor Safety Program, a programmable Transient Rod Withdrawal (TRW) mode has been developed for the Annular Core Research Reactor (ACRR). The programmable mode is a modification of the existing continuous-withdrawal TRW mode and permits speed and direction changes during the pulse sequence. Basically, a TRW operation is similar to a routine pulse operation except that transient rods are mechanically withdrawn rather than pneumatically fired. Being a pulse-type operation, the TRW mode complies with pulse-mode safety system settings. Control system interlocks prevent the pneumatic firing of rods in the TRW mode. The hardware for the programmable TRW mode includes three ACRR transient rods, the ACRR timer, two rod programmers, a minicomputer and a summing circuit for position indication. Each ACRR transient rod is mechanically driven by a stepping motor (rated torque at 4.24 joules) and is capable of a maximum TRW speed of 26.7 centimeters/ second. The maximum reactivity insertion rate is $2.45/second with a transient rod bank worth of $3.00 and $3.47/second with a bank worth of $4.25, which is expected to be installed soon. The ACRR timer is a multifunctional timer used in all operating modes of the reactor. In the programmable TRW mode, the timer starts the rod programmers and drops regulating rods to terminate the operation. Programmed withdrawal capability is provided by one of two rod programmers (a hardwire-based unit and a microprocessor-based unit). The hardwire unit has eight intervals in which speed, direction and distance are selected by switches on the front panel. The microprocessor-based unit has the capability of 64 intervals in which speed, direction, and distance or time can be specified. Programming this unit is accomplished from the front panel or by inputting data from an HP-9845. minicomputer via a digital I/O interface. Self-test programs in the software provide a continual check of an operating

Effect of hydrogen on stresses in anodic oxide film on titanium

International Nuclear Information System (INIS)

Kim, Joong-Do; Pyun, Su-Il; Seo, Masahiro

2003-01-01

Stresses in anodic oxide film on titanium thin film/glass electrode in pH 8.4 borate solution were investigated by a bending beam method. The increases in compressive stress observed with cathodic potential sweeps after formation of anodic oxide film were attributed to the volume expansion due to the compositional change of anodic oxide film from TiO 2 to TiO 2-x (OH) x . The instantaneous responses of changes in stress, Δσ, in the anodic oxide film to potential steps demonstrated the reversible characteristic of the TiO 2-x (OH) x formation reaction. In contrast, the transient feature of Δσ for the titanium without anodic oxide film represented the irreversible formation of TiH x at the metal/oxide interphase. The large difference in stress between with and without the oxide film, has suggested that most of stresses generated during the hydrogen absorption/desorption reside in the anodic oxide film. A linear relationship between changes in stress, Δ(Δσ) des , and electric charge, ΔQ des , during hydrogen desorption was found from the current and stress transients, manifesting that the stress changes were crucially determined by the amount of hydrogen desorbed from the oxide film. The increasing tendency of -Δ(Δσ) des with increasing number of potential steps and film formation potential were discussed in connection with the increase in desorption amount of hydrogen in the oxide film with increasing absorption/desorption cycles and oxide film thickness

Fundamental study on thermo-hydraulic behaviors during power transient, 2

International Nuclear Information System (INIS)

Shinano, M.; Inoue, A.

1988-01-01

Thermo-hydraulic behaviors during power transient of nuclear reactors are studied. Boiling around test rod heated transiently forces to flow out liquid in the test section and generates high pressure pulse. In this study, it is investigated experimentally and analytically that magnitude of pressure pulse and energy conversion efficiency to the mechanical works in cases of fragmentation and non-fragmentation. In analysis, effects of increasing of heat transfer and of interaction area due to fragmentation is considered. Consequently, 1) magnitude of pressure pulse on fragmentation is about 10 times greater than that on non-fragmentation. 2) analytical model can show characteristics of fragmentation processes qualitatively. (author)

Finite strain transient creep of D16T alloy: identification and validation employing heterogeneous tests

Science.gov (United States)

Shutov, A. V.; Larichkin, A. Yu

2017-10-01

A cyclic creep damage model, previously proposed by the authors, is modified for a better description of the transient creep of D16T alloy observed in the finite strain range under rapidly changing stresses. The new model encompasses the concept of kinematic hardening, which allows us to account for the creep-induced anisotropy. The model kinematics is based on the nested multiplicative split of the deformation gradient, proposed by Lion. The damage evolution is accounted for by the classical Kachanov-Rabotnov approach. The material parameters are identified using experimental data on cyclic torsion of thick-walled samples with different holding times between load reversals. For the validation of the proposed material model, an additional experiment is analyzed. Although this additional test is not involved in the identification procedure, the proposed cyclic creep damage model describes it accurately.

Review and comparison of transient creep laws used for natural rock salt

International Nuclear Information System (INIS)

Herrmann, W.; Lauson, H.S.

1981-04-01

A number of creep laws are reviewed, which have been proposed to describe the transient creep of rock salt for use in design calculations of nuclear waste isolation and strategic petroleum reserve repositories. It is shown that they all have the same general form, and their ability to fit creep data for rock salt is tested. Four creep laws are found to fit the data for individual creep tests about equally well. Three of these include steady-state as well as transient creep, while the fourth, equivalent to power-law time hardening in the case of a creep test, does not. Extrapolations at constant stress and temperature of the three creep laws with steady-state creep essentially coincide for times longer than a few months, since the transient creep becomes negligible for such times. Power-law hardening, on the other hand, since it depends on time through a power less than one, predicts much smaller creep strains at very long times

Towards a mechanistic understanding of transient fission gas release

International Nuclear Information System (INIS)

Matthews, J.R.; Small, G.J.

1989-01-01

Recent experimental results on transient fission gas release from oxide fuels are briefly reviewed. These together with associated microstructural observations are compared with the main models for fission gas behaviour. Single gas atom diffusion, bubble migration, heterogeneous percolation and grain boundary sweeping are examined as possible release mechanisms. The role of gas trapping in bubbles and re-solution by irradiation and thermal processes are included in the comparison. As much of the data, and the main range of interest for light water reactor fuels, is for release during mild transients in fuel with a burn-up below 4%, the role of gas retention on grain boundaries is very important and in some cases dominant. The grain boundaries are found to respond very differently to various gas arrival rates and to local temperature conditions. This can lead to early interlinkage and release in some cases, but retention with accompanying large swelling in others. The role of fission products and the local oxygen content of the fuel are found to be important. The effective fuel stoichiometry is likely to change significantly during transients with substantial effects on the transport processes controlling fission gas behaviour. The results of the evaluation of the models are summarized in mechanism maps for intragranular and grain boundary behaviour. (author). 36 refs, 8 figs

Investigation of natural circulation instability and transients in passively safe novel modular reactor

Science.gov (United States)

Shi, Shanbin

The Purdue Novel Modular Reactor (NMR) is a new type small modular reactor (SMR) that belongs to the design of boiling water reactor (BWR). Specifically, the NMR is one third the height and area of a conventional BWR reactor pressure vessel (RPV) with an electric output of 50 MWe. The fuel cycle length of the NMR-50 is extended up to 10 years due to optimized neutronics design. The NMR-50 is designed with double passive engineering safety system. However, natural circulation BWRs (NCBWR) could experience certain operational difficulties due to flow instabilities that occur at low pressure and low power conditions. Static instabilities (i.e. flow excursion (Ledinegg) instability and flow pattern transition instability) and dynamic instabilities (i.e. density wave instability and flashing/condensation instability) pose a significant challenge in two-phase natural circulation systems. In order to experimentally study the natural circulation flow instability, a proper scaling methodology is needed to build a reduced-size test facility. The scaling analysis of the NMR uses a three-level scaling method, which was developed and applied for the design of the Purdue Multi-dimensional Integral Test Assembly (PUMA). Scaling criteria is derived from dimensionless field equations and constitutive equations. The scaling process is validated by the RELAP5 analysis for both steady state and startup transients. A new well-scaled natural circulation test facility is designed and constructed based on the scaling analysis of the NMR-50. The experimental facility is installed with different equipment to measure various thermal-hydraulic parameters such as pressure, temperature, mass flow rate and void fraction. Characterization tests are performed before the startup transient tests and quasi-steady tests to determine the loop flow resistance. The controlling system and data acquisition system are programmed with LabVIEW to realize the real-time control and data storage. The thermal

Medium scale fire tests of propane tanks to study the boiling liquid expanding vapour explosion (BLEVE) and transient two-phase jet release

Energy Technology Data Exchange (ETDEWEB)

Ye Zhifei

1994-07-01

A series of medium scale fire tests were conducted to study boiling liquid expanding vapour explosions (BLEVE) and transient jet releases resulting from thermally induced propane tank ruptures. The tests were conducted using commercial propane contained in automotive propane tanks with a capacity of ca 400 liters. The tanks were brought to failure using a combination of torch and pool fire impingement. Instrumentation was included to measure internal pressure, liquid, vapour and wall temperature distribution, tank and lading mass, external blast overpressure, and fireball thermal radiation. Video and still cameras were used to record the fireball and jet fire shapes and dimensions. Two different kinds of BLEVE failure were observed. For very weak tanks the BLEVE was a single step process where the rupture propagated rapidly along the length of the tank. The duration of these events was measured in milliseconds and it is suggested that the process is driven by the vapour space energy. The other type of BLEVE was a two step process where a crack would start in a weakened area, arrest in a stronger part of the tank, and then start again to end in catastrophic failure. Initial failure and jet type release results in violent boiling and pressure recovery in the tank, leading to restart of the crack and catastrophic failure. Time duration is measured in seconds, and is driven by energy stored in the liquid. A computer model was developed to simulate the transient jet release resulting from finite tank failures, and can predict transient mass flow, tank pressure decay, visible flame length and jet fire thermal radiation. 253 refs., 132 figs., 29 tabs.

Biodegradable elastomers and silicon nanomembranes/nanoribbons for stretchable, transient electronics, and biosensors.

Science.gov (United States)

Hwang, Suk-Won; Lee, Chi Hwan; Cheng, Huanyu; Jeong, Jae-Woong; Kang, Seung-Kyun; Kim, Jae-Hwan; Shin, Jiho; Yang, Jian; Liu, Zhuangjian; Ameer, Guillermo A; Huang, Yonggang; Rogers, John A

2015-05-13

Transient electronics represents an emerging class of technology that exploits materials and/or device constructs that are capable of physically disappearing or disintegrating in a controlled manner at programmed rates or times. Inorganic semiconductor nanomaterials such as silicon nanomembranes/nanoribbons provide attractive choices for active elements in transistors, diodes and other essential components of overall systems that dissolve completely by hydrolysis in biofluids or groundwater. We describe here materials, mechanics, and design layouts to achieve this type of technology in stretchable configurations with biodegradable elastomers for substrate/encapsulation layers. Experimental and theoretical results illuminate the mechanical properties under large strain deformation. Circuit characterization of complementary metal-oxide-semiconductor inverters and individual transistors under various levels of applied loads validates the design strategies. Examples of biosensors demonstrate possibilities for stretchable, transient devices in biomedical applications.

Transient behavior of interface state continuum at InP insulator-semiconductor interface

International Nuclear Information System (INIS)

Hasegawa, H.; Masuda, H.; He, L.; Luo, J.K.; Sawada, T.; Ohno, H.

1987-01-01

To clarify the drain current drift mechanism in InP MISFETs, an isothermal capacitance transient spectroscopy (ICTS) study of the interface state continuum is made on the anodic Al 2 O 3 /native oxide/ InP MIS system. Capture behavior is temperature-independent, non-exponential and extremely slow, whereas emission behavior is temperature- and bias- dependent, and is much faster. The observed behavior is explained quantitatively by the disorder induced gap state (DIGS) model, where states are distributed both in energy and in space. By comparing the transient behavior of interface states with the observed drift behavior of MISFETs, it is concluded that the electron capture by the DIGS continuum is responsible for the drain current drift of MISFETs. This led to a complete computer simulation of the observed current drift behavior

Structural evaluation of electrosleeved tubes under severe accident transients

International Nuclear Information System (INIS)

Majumdar, S.

1999-01-01

A flow stress model was developed for predicting failure of Electrosleeved PWR steam generator tubing under severe accident transients. The Electrosleeve, which is nanocrystalline pure nickel, loses its strength at temperatures greater than 400 C during severe accidents because of grain growth. A grain growth model and the Hall-Petch relationship were used to calculate the loss of flow stress as a function of time and temperature during the accident. Available tensile test data as well as high temperature failure tests on notched Electrosleeved tube specimens were used to derive the basic parameters of the failure model. The model was used to predict the failure temperatures of Electrosleeved tubes with axial cracks in the parent tube during postulated severe accident transients

Ultrasound-Assisted Transient Liquid Phase Bonding of Magnesium Alloy Using Brass Interlayer in Air

Institute of Scientific and Technical Information of China (English)

Zhiwei Lai; Ruishan Xie; Chuan Pan; Xiaoguang Chen; Lei Liu; Wenxian Wang; Guisheng Zou

2017-01-01

The microstructure evolution and oxide film behavior in ultrasound-assisted transient liquid phase (U-TLP) bonding of Mg alloy were investigated by applying different ultrasonic time at 460℃ withbrass interlayer in air.The results indicated that with increasing ultrasonic time,brass interlayer disappeared gradually and the Mg-Cu-Zn eutectic compounds were formed.The eutectic compounds in the joint decreased as the ultrasonic time increased further.The oxide removal process was divided into four steps.Continuous oxide film at the interface was partially fractured by ultrasonic vibration,and then suspended into liquid by undermining eutectic reaction.After that,the suspended oxide film was broken into small oxide fragments by ultrasonic cavitation effect,which was finally squeezed out of the joint by ultrasonic squeeze action.In addition,the mechanical properties of the joints were investigated.The maximum shear strength of the joint reached 105 MPa,which was 100％ of base metal.

Vertical axis wind turbine drive train transient dynamics

Science.gov (United States)

Clauss, D. B.; Carne, T. G.

1982-01-01

Start up of a vertical axis wind turbine causes transient torque oscillations in the drive train with peak torques which may be over two and one half times the rated torque of the turbine. A computer code, based on a lumped parameter model of the drive train, was developed and tested for the low cost 17 meter turbine; the results show excellent agreement with field data. The code was used to predict the effect of a slip clutch on transient torque oscillations. It was demonstrated that a slip clutch located between the motor and brake can reduce peak torques by thirty eight percent.

Experimental study on the 300W class planar type solid oxide fuel cell stack: Investigation for appropriate fuel provision control and the transient capability of the cell performance

International Nuclear Information System (INIS)

Komatsu, Y; Brus, G; Szmyd, J S; Kimijima, S

2012-01-01

The present paper reports the experimental study on the dynamic behavior of a solid oxide fuel cell (SOFC). The cell stack consists of planar type cells with standard power output 300W. A Major subject of the present study is characterization of the transient response to the electric current change, assuming load-following operation. The present studies particularly focus on fuel provision control to the load change. Optimized fuel provision improves power generation efficiency. However, the capability of SOFC must be restricted by a few operative parameters. Fuel utilization factor, which is defined as the ratio of the consumed fuel to the supplied fuel is adopted for a reference in the control scheme. The fuel flow rate was regulated to keep the fuel utilization at 50%, 60% and 70% during the current ramping. Lower voltage was observed with the higher fuel utilization, but achieved efficiency was higher. The appropriate mass flow control is required not to violate the voltage transient behavior. Appropriate fuel flow manipulation can contribute to moderate the overshoot on the voltage that may appear to the current change. The overshoot on the voltage response resulted from the gradual temperature behavior in the SOFC stack module.

Experimental study on the 300W class planar type solid oxide fuel cell stack: Investigation for appropriate fuel provision control and the transient capability of the cell performance

Science.gov (United States)

Komatsu, Y.; Brus, G.; Kimijima, S.; Szmyd, J. S.

2012-11-01

The present paper reports the experimental study on the dynamic behavior of a solid oxide fuel cell (SOFC). The cell stack consists of planar type cells with standard power output 300W. A Major subject of the present study is characterization of the transient response to the electric current change, assuming load-following operation. The present studies particularly focus on fuel provision control to the load change. Optimized fuel provision improves power generation efficiency. However, the capability of SOFC must be restricted by a few operative parameters. Fuel utilization factor, which is defined as the ratio of the consumed fuel to the supplied fuel is adopted for a reference in the control scheme. The fuel flow rate was regulated to keep the fuel utilization at 50%, 60% and 70% during the current ramping. Lower voltage was observed with the higher fuel utilization, but achieved efficiency was higher. The appropriate mass flow control is required not to violate the voltage transient behavior. Appropriate fuel flow manipulation can contribute to moderate the overshoot on the voltage that may appear to the current change. The overshoot on the voltage response resulted from the gradual temperature behavior in the SOFC stack module.

Transient gestational exposure to drinking water containing excess hexavalent chromium modifies insulin signaling in liver and skeletal muscle of rat progeny.

Science.gov (United States)

Shobana, Navaneethabalakrishnan; Aruldhas, Mariajoseph Michael; Tochhawng, Lalmuankimi; Loganathan, Ayyalu; Balaji, Sadhasivam; Kumar, Mani Kathiresh; Banu, Liaquat Alikhan Sheerin; Navin, Ajit Kumar; Mayilvanan, Chinnaiyan; Ilangovan, Ramachandran; Balasubramanian, Karundevi

2017-11-01

Chromium (Cr), an essential micronutrient potentiates insulin action, whereas excess hexavalent Cr (CrVI) acts as an endocrine disruptor. Pregnant mothers living in areas abutting industries using the metal and chromite ore dumps are exposed to ground water contaminated with Cr. Nevertheless, the impact of prenatal exposure to excess CrVI on insulin signaling in the progeny remains obscure. We tested the hypothesis "transient gestational exposure to drinking water containing excess CrVI may modify insulin signaling during postnatal life". Pregnant Wistar rats were given drinking water containing 50, 100 and 200 ppm CrVI (K 2 Cr 2 O 7 ) from gestational day 9-14 encompassing the period of organogenesis; the male progenies were tested at postnatal day 60. Neither fasting blood glucose nor oral glucose tolerance was altered in CrVI treated progeny. Nevertheless, western blot detection pointed out attenuated expression level of insulin receptor (IR), its downstream signaling molecules (IRS-1, pIRS-1 Tyr632 , Akt and pAkt Ser473 ) and organ specific glucose transporters (GLUT2 in liver and GLUT4 in gastrocnemius muscle), along with a significant increase in serum insulin level in male progenies exposed to CrVI. While 14 C-2-deoxy glucose uptake increased in the liver, the same decreased in the skeletal muscle whereas, 14 C-glucose oxidation recorded a consistent decrease in both tissues of CrVI exposed rats. These findings support our hypothesis and suggest that transient gestational exposure to excess CrVI may affect insulin signaling and glucose oxidation in the progeny, predictably rendering them vulnerable to insulin resistance. Copyright © 2017 Elsevier B.V. All rights reserved.

Spherical Indentation Techniques for Creep Property Evaluation Considering Transient Creep

Energy Technology Data Exchange (ETDEWEB)

Lim, Dongkyu; Kim, Minsoo; Lee, Hyungyil [Sogang Univ., Seoul, (Korea, Republic of); Lee, Jin Haeng [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-11-15

Creep through nanoindentations has attracted increasing research attention in recent years. Many studies related to indentation creep tests, however, have simply focused on the characteristics of steady-state creep, and there exist wide discrepancies between the uniaxial test and the indentation test. In this study, we performed a computational simulation of spherical indentations, and we proposed a method for evaluating the creep properties onsidering transient creep. We investigated the material behavior with variation of creep properties and expressed it using regression equations for normalized variables. We finally developed a program to evaluate the creep properties considering transient creep. By using the proposed method, we successfully obtained creep exponents with an average error less than 1.1 and creep coefficients with an average error less than 2.3 from the load-depth curve.

Spherical Indentation Techniques for Creep Property Evaluation Considering Transient Creep

International Nuclear Information System (INIS)

Lim, Dongkyu; Kim, Minsoo; Lee, Hyungyil; Lee, Jin Haeng

2013-01-01

Creep through nanoindentations has attracted increasing research attention in recent years. Many studies related to indentation creep tests, however, have simply focused on the characteristics of steady-state creep, and there exist wide discrepancies between the uniaxial test and the indentation test. In this study, we performed a computational simulation of spherical indentations, and we proposed a method for evaluating the creep properties onsidering transient creep. We investigated the material behavior with variation of creep properties and expressed it using regression equations for normalized variables. We finally developed a program to evaluate the creep properties considering transient creep. By using the proposed method, we successfully obtained creep exponents with an average error less than 1.1 and creep coefficients with an average error less than 2.3 from the load-depth curve

Stress state dependence of transient irradiation creep in 20% cold worked 316 stainless steel

International Nuclear Information System (INIS)

Foster, J.P.; Gilbert, E.R.

1998-01-01

Irradiation creep tests were performed in fast reactors using the stress states of uniaxial tension, biaxial tension, bending and torsion. In order to compare the saturated transient strain irradiation creep component, the test data were converted to equivalent strain and equivalent stress. The saturated transient irradiation creep component was observed to depend on the stress state. The highest value was exhibited by the uniaxial tension stress state, and the lowest by the torsion stress state. The biaxial tension and bending stress state transient component values were intermediate. This behavior appears to be related to the dislocation or microscopic substructure resulting from fabrication processing and the applied stress direction. (orig.)

LOFT/LP-FW-1, Loss of Fluid Test, PWR Response to Loss-of-Feedwater Transient

International Nuclear Information System (INIS)

1989-01-01

1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: The first OECD LOFT experiment was conducted on February 20, 1983. It was designed to evaluate the generic PWR system response during a complete loss-of-feedwater transient. The objective of the experiment was to investigate the performance of primary 'feed and bleed' using a 'bleed' from the PORV and 'feed' from the HPIS to provide decay heat removal and system pressure reduction while maintaining the primary coolant inventory. 3 - Experimental limitations or shortcomings: Short core and steam generator, excessive core bypass, other scaling compromises, and lack of adequate measurements in certain areas

Characterization of ultrasonic spray pyrolysed ruthenium oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Patil, P.S.; Ennaoui, E.A.; Lokhande, C.D.; Mueller, M.; Giersig, M.; Diesner, K.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

1997-11-21

The ultrasonic spray pyrolysis (USP) technique was employed to deposit ruthenium oxide thin films. The films were prepared at 190 C substrate temperature and further annealed at 350 C for 30 min in air. The films were 0.22 {mu} thick and black grey in color. The structural, compositional and optical properties of ruthenium oxide thin films are reported. Contactless transient photoconductivity measurement was carried out to calculate the decay time of excess charge carriers in ruthenium oxide thin films. (orig.) 28 refs.

Transient heat transfer for forced convection flow of helium gas

International Nuclear Information System (INIS)

Liu, Qiusheng; Fukuda, Katsuya; Sasaki, Kenji; Yamamoto, Manabu

1999-01-01

Transient heat transfer coefficients for forced convection flow of helium gas over a horizontal cylinder were measured using a forced convection test loop. The platinum heater with a diameter of 1.0 mm was heated by electric current with an exponential increase of Q 0 exp(t/τ). It was clarified that the heat transfer coefficient approaches the steady-state one for the period τ over 1 s, and it becomes higher for the period of τ shorter than 1 s. The transient heat transfer shows less dependent on the gas flowing velocity when the period becomes very shorter. Semi-empirical correlations for steady-state and transient heat transfer were developed based on the experimental data. (author)

Efficacy and Tolerability of Indiplon in Transient Insomnia

Science.gov (United States)

Rosenberg, Russell; Roth, Thomas; Scharf, Martin B.; Lankford, D. Alan; Farber, Robert

2007-01-01

Objectives: The efficacy of indiplon was evaluated by polysomnography (PSG) in an experimental model of transient insomnia consisting of the first night effect combined with a 2-hour phase advance. Methods: Healthy volunteers age 21–64 years (N=593; 62% female; mean (± SEM) years, 32±0.39) were randomized to double-blind treatment with a single nighttime dose of indiplon (10 mg or 20 mg) or placebo. PSG assessments included latency to persistent sleep (LPS, primary endpoint) and total sleep time (TST); self-report assessments included sleep quality (SQ); next day residual effects were evaluated by the Digit Symbol Substitution Test (DSST), Symbol Copying Test (SCT), and a Visual Analog Scale of sleepiness (VAS). Results: LPS mean (± SEM) values were significantly reduced on indiplon 10 mg (21.2±1.5 minutes) and indiplon 20 mg (16.8±1.1 minutes) compared to placebo (33.1±2.5minutes; p inducing sleep, increasing sleep duration, and improving overall sleep quality without next day residual effects in healthy volunteers in a model of transient insomnia. Citation: Rosenberg R; Roth T; Scharf MB et al. Efficacy and tolerability of indiplon in transient insomnia. J Clin Sleep Med 2007;3(4):374-379. PMID:17694726

Crack propagation tests on the fundamental structure under cyclic thermal transients. Results of nondestructive inspection for cracks

International Nuclear Information System (INIS)

Kobayashi, S.; Horikiri, M.

2001-06-01

This report shows the results of crack inspection in crack propagation tests that were carried out at the Air-cooling Thermal Transient Test Facility (ATTF). Test specimens were made of 304 type austenitic stainless steel, and they were the same cylindrical shape, 1,500 mm in height, 130 mm in outer diameter and 30 mm in thickness. And they had initial slits machined on inner surfaces. Firstly the specimens were heated up to 650degC in a furnace, then cooled by pressurized air blowing through the specimen for 90 seconds. These cyclic changes of temperature gradients in the wall of specimens were loaded. Specimens were tested for several years. The specimen No. CPTT-102 with machined two circumferential slits and two semi-elliptical slits was tested up to 10,000 cycles. And the specimen No. CPTT-103 with machined six semi-elliptical slits of different length respectively was tested up to 5,000 cycles. Cracks of specimens were inspected nondestructively for a giving cycle in these tests. Applied inspection methods were ultra-sonic testing, potential-drop method and inner surface observation. Ultra-sonic testing was carried out by applying the pulse-echo method. Potential-drop testing was carried out by measurement of localized constant direct current beyond cracks. Photographs of the inner surface of specimens were taken using a bore-scope. The results of ultra-sonic testing have been close to destructive test results. The depth of crack by the potential-drop method was almost corresponding to destructive test results, too. Photographs of the inner surface were synthesized by the computer, and connection between main crack and hair crack was observed. (author)

Effect of additional holes on transient thermal fatigue life of gas turbine casing

Directory of Open Access Journals (Sweden)

H. Bazvandi

2017-10-01

Full Text Available Gas turbines casings are susceptible to cracking at the edge of eccentric pin hole, which is the most likely position for crack initiation and propagation. This paper describes the improvement of transient thermal fatigue crack propagation life of gas turbines casings through the application of additional holes. The crack position and direction was determined using non-destructive tests. A series of finite element patterns were developed and tested in ASTM-A395 elastic perfectly-plastic ductile cast iron. The effect of arrangement of additional holes on transient thermal fatigue behavior of gas turbines casings containing hole edge cracks was investigated. ABAQUS finite element package and Zencrack fracture mechanics code were used for modeling. The effect of the reduction of transient thermal stress distribution around the eccentric pin hole on the transient thermal fatigue crack propagation life of the gas turbines casings was discussed. The result shows that transient thermal fatigue crack propagation life could be extended by applying additional holes of larger diameter and decreased by increasing the vertical distance, angle, and distance between the eccentric pin hole and the additional holes. The results from the numerical predictions were compared with experimental data.

Effect of transient annealing on patterned CoFeB-based magnetic tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Wu, Kuo-Ming; Huang, Chao-Hsien; Lin, Shiao-Chi; Wu, Jong-Ching [Department of Physics and Taiwan SPIN Research Center, National Changhua University of Education, Changhua 50007 (China); Kao, Ming-Jer; Tsai, Ming-Jinn [Industrial Technology Research Institute, Hsinchu 31040 (China); Horng, Lance

2007-12-15

In this study, the transient annealing effect on the switching behavior of microstructured Co{sub 60}Fe{sub 20}B{sub 20}-based magnetic tunnel junctions has been studied through magnetoresistance measurements (R-H loop). Elliptical shape of devices with long/short axis of 4/2 micrometers was patterned out of sheet film stack of: Ta(20)/PtMn(15)/CoFeB(3)/Al(0.7)-oxide/CoFeB(2)/Ru(8)/Ta(40) (thickness unit in nanometers) after a conventional long time field cooling annealing. The transient annealing was then executed by sample loading into a furnace with pre-set temperatures ranging from 100 to 400 C for only 5 minutes in the absence of any external magnetic field. The vortex-like reverse of free layer in as-etched MTJ evidently changes to single-domain-like reverser after 200{proportional_to}250 C transient annealing. The magnetoresistance was found to increase with increasing annealing temperatures up to 265 C and then slowly decrease at higher annealing temperatures. The transient thermal annealing creates obvious efforts to repair magnetic properties of MTJ cell befor 265 C annealing and results in less damage at temperature of 350 C and 400 C. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Effect of transient annealing on patterned CoFeB-based magnetic tunnel junctions

International Nuclear Information System (INIS)

Wu, Kuo-Ming; Huang, Chao-Hsien; Lin, Shiao-Chi; Wu, Jong-Ching; Kao, Ming-Jer; Tsai, Ming-Jinn; Horng, Lance

2007-01-01

In this study, the transient annealing effect on the switching behavior of microstructured Co 60 Fe 20 B 20 -based magnetic tunnel junctions has been studied through magnetoresistance measurements (R-H loop). Elliptical shape of devices with long/short axis of 4/2 micrometers was patterned out of sheet film stack of: Ta(20)/PtMn(15)/CoFeB(3)/Al(0.7)-oxide/CoFeB(2)/Ru(8)/Ta(40) (thickness unit in nanometers) after a conventional long time field cooling annealing. The transient annealing was then executed by sample loading into a furnace with pre-set temperatures ranging from 100 to 400 C for only 5 minutes in the absence of any external magnetic field. The vortex-like reverse of free layer in as-etched MTJ evidently changes to single-domain-like reverser after 200∝250 C transient annealing. The magnetoresistance was found to increase with increasing annealing temperatures up to 265 C and then slowly decrease at higher annealing temperatures. The transient thermal annealing creates obvious efforts to repair magnetic properties of MTJ cell befor 265 C annealing and results in less damage at temperature of 350 C and 400 C. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Prenatal Diagnosis of Transient Abnormal Myelopoiesis in a Down Syndrome Fetus

International Nuclear Information System (INIS)

Kim, Gwang Jun; Lee, Eun Sil

2009-01-01

We report a case of transient abnormal myelopoiesis in a Down syndrome fetus diagnosed at 28 +3 weeks of gestation that rapidly progressed to intrauterine death 10 days later. Fetal hepatosplenomegaly with cerebral ventriculomegaly, although not specific, may be a suggestive finding of Down syndrome with transient abnormal myelopoiesis. Prompt fetal blood sampling for liver function test and chromosomal analysis are mandatory for early detection and management

Analysis of the Mannshan Unit 2 full load rejection transient

International Nuclear Information System (INIS)

Kang, J.C.; Pei, B.S.; Yu, G.P.; Yuann, R.Y.

1987-01-01

Mannshan Unit 2 is a Westinghouse three-loop pressurized water reactor with a rated core power of 2775 MW(thermal) and a rated core flow of 4702 kg/s. Before full power operation, a planned net load rejection was performed during the startup test by opening the main transformer highside breakers. The generator power rapidly reduced to station load. All 16 steam dump valves immediately popped open, and control bank-D rods automatically stepped in as the temperature difference T/sub avg/ - T/sub ref/ reached a programmed 2.8 0 C. Nuclear power decreased smoothly as control rods were inserted into the core. The pressurizer pressure and liquid levels also dropped. Neither safety injection nor reactor trip occurred during this transient. The test was done to verify that the whole system would function properly under a transient to keep the reactor from scramming and that the vessel integrity would also be protected. In this study, which is the preliminary stage of RELAP5/MOD2 transient simulation of the Mannshan PWR plants, system thermal-hydraulic response is tested first and isolated from the neutronic effects. The variation of core power versus time curve was extracted from the power test data to serve as a time varying boundary condition. The comparison of the analytical results of four major parameters (pressurizer pressure, average temperature of the core, steam dump flow rate, and feedwater flow rate) from RELAP5/MOD2 and the power test data is illustrated

Investigation on the transient enthalpy of coal combustion

Energy Technology Data Exchange (ETDEWEB)

Fu, Pei-fang; Wang, Na; Yu, Bo; Zhang, Bin; Liu, Yang; Zhou, Huai-chun [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

2013-07-01

The transient enthalpy ({Delta}h) of coal/char combustion of the three different coals (including anthracite, bituminous, and lignite) during the process of combustion is determined as a function of burn-off degree by using thermo-gravimetric-differential scanning calorimeter (TG-DSC) simultaneous thermal analyzer, and The error of determining calorific values of coals/chars is less 5% compared the results of TG-DSC with that of an automatic isoperibol calorimeter. It is found that In the initial stage, all the {Delta}h of coals are greater than that of the char pyrolysized from parent coal for many of volatiles contained more a great deal of heat per unit mass oxidized at low temperature, it also imply that coal is more easily ignited than char corresponded; And in the middle stage, all the {Delta}h of coals is lower than that of the char pyrolysized, so the pyrolysized char oxidation can supply much more of thermo-energy per unit mass. {Delta}h are almost a constant when the burn-off degree is equal to between 0.35/0.15 and 0.95/0.85 for ZCY bituminous coal/char and JWY anthracite/char, between 0.35/0.35 and 0.75/0.9 for SLH lignite/char; In the later stage, the {Delta}h of the coal/char decreased with the burn-off degree, it imply that the activity of the coal/char decreases. Therefore, coal pyrolysis changes not only the structure of char, but also the property of release heat; the transient enthalpy of coal/char combustion has been in change with the burn-out degree.

Analysis and computer simulation for transient flow in complex system of liquid piping

International Nuclear Information System (INIS)

Mitry, A.M.

1985-01-01

This paper is concerned with unsteady state analysis and development of a digital computer program, FLUTRAN, that performs a simulation of transient flow behavior in a complex system of liquid piping. The program calculates pressure and flow transients in the liquid filled piping system. The analytical model is based on the method of characteristics solution to the fluid hammer continuity and momentum equations. The equations are subject to wide variety of boundary conditions to take into account the effect of hydraulic devices. Water column separation is treated as a boundary condition with known head. Experimental tests are presented that exhibit transients induced by pump failure and valve closure in the McGuire Nuclear Station Low Level Intake Cooling Water System. Numerical simulation is conducted to compare theory with test data. Analytical and test data are shown to be in good agreement and provide validation of the model

"UCx fission targets oxidation test stand"

CERN Document Server

Lacroix, Rachel

2014-01-01

"Set up a rig dedicated to the oxidation of UCx and define a procedure for repeatable, reliable and safe method for converting UC2 fission targets into an acceptable uranium carbide oxide waste for subsequent disposal by the Swiss Authorities."

Towards a utilisation of transient processing in the technology of high efficiency silicon solar cells

International Nuclear Information System (INIS)

Eichhammer, W.

1989-01-01

The utilization of transient processing in the technology of high efficient silicon solar cells is investigated. An ultraviolet laser (an ArF pulsed excimer laser working at 193 nm) is applied. Laser processing induces only a short superficial melting of the material and does not modify the transport properties in the base of the material. This mode of processing associated to ion implantation to form the junction as well as an oxide layer in an atmosphere of oxygen. The volume was left entirely cold in this process. The results of the investigation show: that an entirely cold process of solar cell fabrication needs a thermal treatment at a temperature around 600 C; that the oxides obtained are not satisfying as passivating layers; and that the Rapid Thermal Processing (RTP) induced recombination centers are not directly related to the quenching step but a consequence of the presence of metal impurities. The utilisation of transient processing in the adiabatic regime (laser) and in the rapid isothermal regime (RTP) are possible as two complementary techniques for the realization of high efficiency solar cells

Possible effects of oxidation on the transient release of fission gas from UO2

International Nuclear Information System (INIS)

Stoner, H.C.; Matthews, J.R.; Wood, M.H.

1981-01-01

The effect of varying the fuel composition from UO 2 to UOsub(2.3), on the transient behaviour of fission gas is simulated on the assumption that surface diffusion behaves in a similar manner to volume diffusion. The results may help in the understanding of fuel behaviour after pin failure in accident conditions in thermal reactor systems. (author)

Air oxidation of Zircaloy-4, M5 (registered) and ZIRLOTM cladding alloys at high temperatures

International Nuclear Information System (INIS)

Steinbrueck, M.; Boettcher, M.

2011-01-01

The paper presents the results of isothermal and transient oxidation experiments of the advanced cladding alloys M5 (registered) and ZIRLO TM in comparison to Zircaloy-4 in air at temperatures from 973 to 1853 K. Generally, oxidation in air leads to a strong degradation of the cladding material. The main mechanism of this process is the formation of zirconium nitride and its re-oxidation. From the point of view of safety, the barrier effect of the fuel cladding is lost much earlier than during accident transients with a steam atmosphere only. Comparison of the three alloys investigated reveals a qualitatively similar, but quantitatively varying oxidation behavior in air. The mainly parabolic oxidation kinetics, where applicable, is comparable for the three alloys. Strong differences of up to 500% in oxidation rates were observed after transition to linear kinetics at temperatures below 1300 K. The paper presents kinetic rate constants as well as critical times and oxide scale thicknesses at the point of transition from parabolic to linear kinetics.

Oxidative stress in response to aerobic and anaerobic power testing: influence of exercise training and carnitine supplementation.

Science.gov (United States)

Bloomer, Richard J; Smith, Webb A

2009-01-01

The purpose of this study is to compare the oxidative stress response to aerobic and anaerobic power testing, and to determine the impact of exercise training with or without glycine propionyl-L-carnitine (GPLC) in attenuating the oxidative stress response. Thirty-two subjects were assigned (double blind) to placebo, GPLC-1 (1g PLC/d), GPLC-3 (3g PLC/d) for 8 weeks, plus aerobic exercise. Aerobic (graded exercise test: GXT) and anaerobic (Wingate cycle) power tests were performed before and following the intervention. Blood was taken before and immediately following exercise tests and analyzed for malondialdehyde (MDA), hydrogen peroxide (H2O2), and xanthine oxidase activity (XO). No interaction effects were noted. MDA was minimally effected by exercise but lower at rest for both GPLC groups following the intervention (p = 0.044). A time main effect was noted for H2O2 (p = 0.05) and XO (p = 0.003), with values increasing from pre- to postexercise. Both aerobic and anaerobic power testing increase oxidative stress to a similar extent. Exercise training plus GPLC can decrease resting MDA, but it has little impact on exercise-induced oxidative stress biomarkers.

PHOEBUS/UHTREX: a preliminary study of a low-cost facility for transient tests of LMFBR fuel

International Nuclear Information System (INIS)

Kirk, W.L.

1976-08-01

The results of a brief preliminary design study of a facility for transient nuclear tests of fast breeder reactor fuel are described. The study is based on the use of a reactor building originally built for the UHTREX reactor, and the use of some reactor hardware and reactor design and fabrication technology remaining from the Phoebus-2 reactor of the Rover nulcear rocket propulsion program. The facility is therefore currently identified as the PHOEBUS/UHTREX facility. This facility is believed capable of providing early information regarding fast reactor core accident energetics issues which will be very valuable to the overall LMFBR safety program. Facility performance in conjunction with a reference 127-fuel pin experiment is described. Low cost and early availability of the facility were emphasized in the selection of design features and parameters

PHOEBUS/UHTREX: a preliminary study of a low-cost facility for transient tests of LMFBR fuel

Energy Technology Data Exchange (ETDEWEB)

Kirk, W.L. (comp.)

1976-08-01

The results of a brief preliminary design study of a facility for transient nuclear tests of fast breeder reactor fuel are described. The study is based on the use of a reactor building originally built for the UHTREX reactor, and the use of some reactor hardware and reactor design and fabrication technology remaining from the Phoebus-2 reactor of the Rover nulcear rocket propulsion program. The facility is therefore currently identified as the PHOEBUS/UHTREX facility. This facility is believed capable of providing early information regarding fast reactor core accident energetics issues which will be very valuable to the overall LMFBR safety program. Facility performance in conjunction with a reference 127-fuel pin experiment is described. Low cost and early availability of the facility were emphasized in the selection of design features and parameters.

Femtosecond transient absorption spectroscopy of silanized silicon quantum dots

Science.gov (United States)

Kuntermann, Volker; Cimpean, Carla; Brehm, Georg; Sauer, Guido; Kryschi, Carola; Wiggers, Hartmut

2008-03-01

Excitonic properties of colloidal silicon quantum dots (Si qdots) with mean sizes of 4nm were examined using stationary and time-resolved optical spectroscopy. Chemically stable silicon oxide shells were prepared by controlled surface oxidation and silanization of HF-etched Si qdots. The ultrafast relaxation dynamics of photogenerated excitons in Si qdot colloids were studied on the picosecond time scale from 0.3psto2.3ns using femtosecond-resolved transient absorption spectroscopy. The time evolution of the transient absorption spectra of the Si qdots excited with a 150fs pump pulse at 390nm was observed to consist of decays of various absorption transitions of photoexcited electrons in the conduction band which overlap with both the photoluminescence and the photobleaching of the valence band population density. Gaussian deconvolution of the spectroscopic data allowed for disentangling various carrier relaxation processes involving electron-phonon and phonon-phonon scatterings or arising from surface-state trapping. The initial energy and momentum relaxation of hot carriers was observed to take place via scattering by optical phonons within 0.6ps . Exciton capturing by surface states forming shallow traps in the amorphous SiOx shell was found to occur with a time constant of 4ps , whereas deeper traps presumably localized in the Si-SiOx interface gave rise to exciton trapping processes with time constants of 110 and 180ps . Electron transfer from initially populated, higher-lying surface states to the conduction band of Si qdots (>2nm) was observed to take place within 400 or 700fs .

Oxidation Study of an Ultra High Temperature Ceramic Coatings Based on HfSiCN

Science.gov (United States)

Sacksteder, Dagny; Waters, Deborah L.; Zhu, Dongming

2018-01-01

High temperature fiber-reinforced ceramic matrix composites (CMCs) are important for aerospace applications because of their low density, high strength, and significantly higher-temperature capabilities compared to conventional metallic systems. The use of the SiCf/SiC and Cf/SiC CMCs allows the design of lighter-weight, more fuel efficient aircraft engines and also more advanced spacecraft airframe thermal protection systems. However, CMCs have to be protected with advanced environmental barrier coatings when they are incorporated into components for the harsh environments such as in aircraft engine or spacecraft applications. In this study, high temperature oxidation kinetics of an advanced HfSiCN coating on Cf/SiC CMC substrates were investigated at 1300 C, 1400 C, and 1500 C by using thermogravimetric analysis (TGA). The coating oxidation reaction parabolic rate constant and activation energy were estimated from the experimental results. The oxidation reaction studies showed that the coatings formed the most stable, predominant HfSiO4-HfO2 scales at 1400 C. A peroxidation test at 1400 C then followed by subsequent oxidation tests at various temperatures also showed more adherent scales and slower scale growth because of reduced the initial transient oxidation stage and increased HfSiO4-HfO2 content in the scales formed on the HfSiCN coatings.

Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

OpenAIRE

Auer, Corinna; Lang, Michael; Couturier, Karine; Nielsen, Eva Ravn; Mc Phail, Stephen; Tsotridis, Georgios; FU, Qingxi; Chan, Siew Hwa

2015-01-01

The market penetration of fuel and electrolysis cell energy systems in Europe requires the development of reliable assessment, testing and prediction of performance and durability of solid oxide cells and stacks (SOC). To advance in this field the EU-project “SOCTESQA” was launched in May 2014. Partners from different countries in Europe and one external party from Singapore are working together to develop uniform and industry wide test procedures and protocols for SOC cell/stack assembly. In...

A measurement of the density and compressibility of (U, Pu)-mixed oxide at 3432 kJ/kg (7356 K)

International Nuclear Information System (INIS)

Breitung, W.

1987-05-01

In a transient in-pile heating test the density of liquid (U, Pu)-mixed oxide at 3432±103 kJ/kg was measured to be 5027±132 kg/m 3 . The corresponding temperature is estimated to 7356±212 K. The isothermal compressibility of the mixed oxide was evaluated to 2.85 (±1.65) x 10 -4 /MPa at the same temperature. Based on these new data and previously existing measurements, new relations are proposed for the following properties of liquid UO 2 and (U, Pu)O 2 , as well: density - enthalpy, density - temperature, thermal expansion - temperature, and isothermal compressibility - temperature. (orig.) [de

A High Temperature Experimental Characterization Procedure for Oxide-Based Thermoelectric Generator Modules under Transient Conditions

DEFF Research Database (Denmark)

Man, Elena Anamaria; Schaltz, Erik; Rosendahl, Lasse

2015-01-01

Characterization methods for thermoelectric generator (TEG) modules play an important role in studying their behavior and in enhancing the performance and simulation of TEG systems also. The purpose of this study is to analyze the behavior in transient and steady-state of the temperature applied...

Prenatal Diagnosis of Transient Abnormal Myelopoiesis in a Down Syndrome Fetus

Energy Technology Data Exchange (ETDEWEB)

Kim, Gwang Jun; Lee, Eun Sil [Chung-Ang University School of Medicine, Seoul (Korea, Republic of)

2009-04-15

We report a case of transient abnormal myelopoiesis in a Down syndrome fetus diagnosed at 28{sup +3} weeks of gestation that rapidly progressed to intrauterine death 10 days later. Fetal hepatosplenomegaly with cerebral ventriculomegaly, although not specific, may be a suggestive finding of Down syndrome with transient abnormal myelopoiesis. Prompt fetal blood sampling for liver function test and chromosomal analysis are mandatory for early detection and management.

Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

Investigation of practical use situation and performance for electric transient analysis programs in the U.S. nuclear power plants

International Nuclear Information System (INIS)

Shimada, Yoshio

2010-01-01

The purposes of the present study are firstly to investigate the status of practical use of electric transient analysis programs used in U.S. nuclear power plants, which has been extracted as good examples from the information analysis of overseas troubles, and secondly to select a program to be recommended for use in implementing electric transient analysis in domestic nuclear power plants. In addition, to promote its practical use, a selected electric transient analysis program was tested by simulating the transient response during a load sequence test of an emergency diesel generator (EDG) in a domestic representative nuclear plant to evaluate its simulation accuracy by comparing its result with the measured plant data. The results obtained are as follows: (1) In U.S. nuclear power plants, simulations using electric transient analysis programs, such as ETAP, EMPT, etc., are widely performed, which contributed to improve the plant safety. (2) A selected transient analysis program EMTP was verified in its accuracy in terms of transient response of active power, current, voltage and frequency of the EDG during the load sequence test in a domestic representative nuclear power plant. (author)

Strongly oxidizing perylene-3,4-dicarboximides for use in water oxidation photoelectrochemical cells

Energy Technology Data Exchange (ETDEWEB)

Lindquist, Rebecca J.; Phelan, Brian T.; Reynal, Anna; Margulies, Eric A.; Shoer, Leah E.; Durrant, James R.; Wasielewski, Michael R.

2016-01-01

Perylene-3,4-dicarboximide (PMI) based chromophores have demonstrated the ability to inject electrons into TiO2 for dye-sensitized solar cell applications and to accept electrons from metal complexes relevant to water oxidation, but they are nearly unexplored for use in photoelectrochemical cells (PECs) for solar fuels generation. A series of related PMIs with high oxidation potentials and carboxylate binding groups was synthesized and investigated for this purpose. Charge injection and recombination dynamics were measured using transient absorption (TA) spectroscopy on the picosecond to second timescales. The dynamics and electron injection yields were correlated with the PMI energetics and structures. Injection began in less than 1 ps for the dye with the best performance and a significant charge-separated state yield remained at long times. Finally, this chromophore was used to oxidize a covalently bound water oxidation precatalyst following electron injection into TiO2 to demonstrate the utility of the dyes for use in PECs.

Single Event Effects (SEE) for Power Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)

Science.gov (United States)

Lauenstein, Jean-Marie

2011-01-01

Single-event gate rupture (SEGR) continues to be a key failure mode in power MOSFETs. (1) SEGR is complex, making rate prediction difficult SEGR mechanism has two main components: (1) Oxide damage-- Reduces field required for rupture (2) Epilayer response -- Creates transient high field across the oxide.

Heavy-ion induced current through an oxide layer

International Nuclear Information System (INIS)

Takahashi, Yoshihiro; Ohki, Takahiro; Nagasawa, Takaharu; Nakajima, Yasuhito; Kawanabe, Ryu; Ohnishi, Kazunori; Hirao, Toshio; Onoda, Shinobu; Mishima, Kenta; Kawano, Katsuyasu; Itoh, Hisayoshi

2007-01-01

In this paper, the heavy-ion induced current in MOS structure is investigated. We have measured the transient gate current in a MOS capacitor and a MOSFET induced by single heavy-ions, and found that a transient current can be observed when the semiconductor surface is under depletion condition. In the case of MOSFET, a transient gate current with both positive and negative peaks is observed if the ion hits the gate area, and that the total integrated charge is almost zero within 100-200 ns after irradiation. From these results, we conclude that the radiation-induced gate current is dominated by a displacement current. We also discuss the generation mechanism of the radiation-induced current through the oxide layer by device simulation

Improved ASTM G72 Test Method for Ensuring Adequate Fuel-to-Oxidizer Ratios

Science.gov (United States)

Juarez, Alfredo; Harper, Susana Tapia

2016-01-01

The ASTM G72/G72M-15 Standard Test Method for Autogenous Ignition Temperature of Liquids and Solids in a High-Pressure Oxygen-Enriched Environment is currently used to evaluate materials for the ignition susceptibility driven by exposure to external heat in an enriched oxygen environment. Testing performed on highly volatile liquids such as cleaning solvents has proven problematic due to inconsistent test results (non-ignitions). Non-ignition results can be misinterpreted as favorable oxygen compatibility, although they are more likely associated with inadequate fuel-to-oxidizer ratios. Forced evaporation during purging and inadequate sample size were identified as two potential causes for inadequate available sample material during testing. In an effort to maintain adequate fuel-to-oxidizer ratios within the reaction vessel during test, several parameters were considered, including sample size, pretest sample chilling, pretest purging, and test pressure. Tests on a variety of solvents exhibiting a range of volatilities are presented in this paper. A proposed improvement to the standard test protocol as a result of this evaluation is also presented. Execution of the final proposed improved test protocol outlines an incremental step method of determining optimal conditions using increased sample sizes while considering test system safety limits. The proposed improved test method increases confidence in results obtained by utilizing the ASTM G72 autogenous ignition temperature test method and can aid in the oxygen compatibility assessment of highly volatile liquids and other conditions that may lead to false non-ignition results.

Analysis of the transient compressible vapor flow in heat pipes

Science.gov (United States)

Jang, J. H.; Faghri, A.; Chang, W. S.

1989-01-01

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Analysis of the transient compressible vapor flow in heat pipe

International Nuclear Information System (INIS)

Jang, J.H.; Faghri, A.; Chang, W.S.

1989-07-01

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures

Analysis of the transient compressible vapor flow in heat pipe

Science.gov (United States)

Jang, Jong Hoon; Faghri, Amir; Chang, Won Soon

1989-01-01

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Transient failure behavior of HT9

International Nuclear Information System (INIS)

Huang, F.H.

1994-07-01

Alloy HT9 has-been chosen as candidate materials for fast and fusion reactor applications because the.material exhibits excellent resistance to void swelling. However, ferritic alloys are known to undergo a ductile-brittle transition as the test temperature is decreased. This inherent problem has limited their applications to reactor component materials subjected to low neutron exposures. Despite the ductile-brittle transition problem, results show that the materials exhibit superior resistance to fracture under very high neutron fluences at irradiation temperatures above 380C. Results also show that the transient behavior for HT9 cladding specimens taken from the fuel column region and cladding taken from outside the fuel column or unirradiated cladding are the same. HT9 cladding maintained its transient strength with irradiation to a fluence of 9 x 10 22 n/cm 2 (E > 0.1 MeV)

Transient two-phase performance of LOFT reactor coolant pumps

International Nuclear Information System (INIS)

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

Technical test description of activities to determine the potential for spent fuel oxidation in a tuff repository

International Nuclear Information System (INIS)

Einziger, R.E.

1985-06-01

The potential change in the oxidation state of spent fuel during its residence in a repository must be known to evaluate its radionuclide retention capabilities. Once the container breaches, the spent fuel in a repository sited above the water table will be exposed to a moist air atmosphere at low temperatures. Thermodynamically, there is no reason why the fuel should not oxidize to a higher oxidation state under these conditions, given enough time. Depending on the rate of oxidation, higher oxides with potentially higher leach rates may eventually form or the cladding may even split open. If either of these oxidation effects occurs, the ability of spent fuel to retard radionuclide migration will be reduced. A technical test description is presented to study spent fuel oxidation at low temperatures characteristic of the post-container breach period and at high temperatures in a moist inert atmosphere characteristic of a sealed container with waterlogged fuel, early in the repository life. The approach taken will be to perform tests and evaluations to gain understanding of the operative oxidation mechanisms, to obtain oxidation rate data, and to make projections of potential long-term fuel oxidation states. Time and temperature dependence of existing models will be evaluated, and the dependence of the model projections on fuel variables will be determined. 27 refs., 7 figs., 4 tabs

Transients: The regulator's view

International Nuclear Information System (INIS)

Sheron, B.W.; Speis, T.P.

1984-01-01

This chapter attempts to clarify the basis for the regulator's concerns for transient events. Transients are defined as both anticipated operational occurrences and postulated accidents. Recent operational experience, supplemented by improved probabilistic risk analysis methods, has demonstrated that non-LOCA transient events can be significant contributors to overall risk. Topics considered include lessons learned from events and issues, the regulations governing plant transients, multiple failures, different failure frequencies, operator errors, and public pressure. It is concluded that the formation of Owners Groups and Regulatory Response Groups within the owners groups are positive signs of the industry's concern for safety and responsible dealing with the issues affecting both the US NRC and the industry

Transient diagnosis system using quantum-inspired computing and Minkowski distance

Energy Technology Data Exchange (ETDEWEB)

Nicolau, Andressa dos Santos; Schirru, Roberto, E-mail: andressa@lmp.ufrj.b, E-mail: schirru@lmp.ufrj.b [Federal University of Rio de Janeiro (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Nuclear Engineering Program

2011-07-01

This paper proposes a diagnosis system model for identification of transient in a PWR nuclear power plant, optimized by the Quantum Inspired Evolutionary Algorithm - QEA in order to help nuclear power plant operator reduce his cognitive load and increase his available time to maintain the plant operating in a safe condition. This method was developed in order to be able to recognize the normal condition and three accidents of the design basis list of the nuclear power plant Angra 2, postulated in the Final Safety Analysis Report (FSAR). This System compares the similarly distance between the set of variables of the anomalous event, in a given time t, and the centroids of the design-basis transient variables. The lower similarly distance indicates the class of the transient to which the anomalous event belongs. The QEA was then used to find the best position of the centroids of each class of the selected transients. Such positions maximize the number of the correct classifications. Unlike the diagnosis system proposed in the literature, Minkowski distance was employed to calculate the similarity distance. The signatures of four transients were submitted to 1% and 2% of noise, and tested with prototype vector found by QEA. The results showed that the present transient diagnostic system was successfully implemented in the nuclear accident identification problem and was compatible with the techniques presented in the literature. (author)

Transient diagnosis system using quantum-inspired computing and Minkowski distance

International Nuclear Information System (INIS)

Nicolau, Andressa dos Santos; Schirru, Roberto