WorldWideScience

Sample records for internal proton leaks

  1. Role of the Transmembrane Potential in the Membrane Proton Leak

    Czech Academy of Sciences Publication Activity Database

    Ruprecht, A.; Sokolenko, E. A.; Beck, V.; Ninnemann, O.; Jabůrek, Martin; Trimbuch, T.; Klishin, S. S.; Ježek, Petr; Skulachev, V. P.; Pohl, E. E.

    2010-01-01

    Roč. 98, č. 8 (2010), s. 1503-1511 ISSN 0006-3495 R&D Projects: GA MŠk ME09018; GA ČR(CZ) GA303/07/0105 Institutional research plan: CEZ:AV0Z50110509 Keywords : proton leak * membrane potential * uncoupling proteins Subject RIV: BO - Biophysics Impact factor: 4.218, year: 2010

  2. Phylogenetic differences of mammalian basal metabolic rate are not explained by mitochondrial basal proton leak.

    Science.gov (United States)

    Polymeropoulos, E T; Heldmaier, G; Frappell, P B; McAllan, B M; Withers, K W; Klingenspor, M; White, C R; Jastroch, M

    2012-01-07

    Metabolic rates of mammals presumably increased during the evolution of endothermy, but molecular and cellular mechanisms underlying basal metabolic rate (BMR) are still not understood. It has been established that mitochondrial basal proton leak contributes significantly to BMR. Comparative studies among a diversity of eutherian mammals showed that BMR correlates with body mass and proton leak. Here, we studied BMR and mitochondrial basal proton leak in liver of various marsupial species. Surprisingly, we found that the mitochondrial proton leak was greater in marsupials than in eutherians, although marsupials have lower BMRs. To verify our finding, we kept similar-sized individuals of a marsupial opossum (Monodelphis domestica) and a eutherian rodent (Mesocricetus auratus) species under identical conditions, and directly compared BMR and basal proton leak. We confirmed an approximately 40 per cent lower mass specific BMR in the opossum although its proton leak was significantly higher (approx. 60%). We demonstrate that the increase in BMR during eutherian evolution is not based on a general increase in the mitochondrial proton leak, although there is a similar allometric relationship of proton leak and BMR within mammalian groups. The difference in proton leak between endothermic groups may assist in elucidating distinct metabolic and habitat requirements that have evolved during mammalian divergence.

  3. Environmental risk comparisons with internal methods of UST leak detection

    International Nuclear Information System (INIS)

    Durgin, P.B.

    1993-01-01

    The past five years have seen a variety of advances in how leaks can be detected from within underground storage tanks. Any leak-detection approach employed within a storage tanks must be conducted at specific time intervals and meet certain leak-rate criteria according to federal and state regulations. Nevertheless, the potential environmental consequences of leak detection approaches differ widely. Internal, volumetric UST monitoring techniques have developed over time including: (1) inventory control with stick measurements, (2) precision tank testing, (3) automatic tank gauging (ATG), (4) statistical inventory reconciliation (SIR), and (5) statistical techniques with automatic tank gauging. An ATG focuses on the advantage of precise data but measured for only a brief period. On the other hand, stick data has less precision but when combined with SIR over extended periods it too can detect low leak rates. Graphs demonstrate the comparable amounts of fuel than can leak out of a tank before being detected by these techniques. The results indicate that annual tank testing has the greatest potential for large volumes of fuel leaking without detection while new statistical approaches with an ATG have the least potential. The environmental implications of the volumes of fuel leaked prior to detection are site specific. For example, if storage tank is surrounded by a high water table and in a sole-source aquifer even small leaks may cause problems. The user must also consider regulatory risks. The level of environmental and regulatory risk should influence selection of the UST leak detection method

  4. A study on the evaluation of internal leak in valve using acoustic emission method(3)

    International Nuclear Information System (INIS)

    Lee, Sang Guk; Lee, Wook Ryun; Park, Jong Hyuck; Kim, Kwang Hong

    2005-01-01

    The objective of this study is to estimate the feasibility of acoustic emission method for the internal leak from the valves. In this study, valve leak tests using various types of specimen simulated seat damage were performed in order to analyzer acoustic emission properties when leaks arise in valve seat. As a result of leak test for specimens simulated valve seat, we conformed that leak sound level increased in proportion to the increase of hole diameter and leak velocity, and decreased in proportion to the increase of leak depth. And also, leak sound level has hysteresis for leak velocity. From the experimental results, it was suggested that the acoustic emission method for monitoring of leak was feasible.

  5. Leaks in the internal water supply piping systems

    Directory of Open Access Journals (Sweden)

    Orlov Evgeniy Vladimirovich

    2015-03-01

    Full Text Available Great water losses in the internal plumbing of a building lead to the waste of money for a fence, purification and supply of water volumes in excess. This does not support the concept of water conservation and resource saving lying today in the basis of any building’s construction having plumbing. Leakage means unplanned of water losses systems in domestic water supply systems (hot or cold as a result of impaired integrity, complicating the operation of a system and leading to high costs of repair and equipment restoration. A large number of leaks occur in old buildings, where the regulatory service life of pipelines has come to an end, and the scheduled repair for some reason has not been conducted. Steel pipelines are used in the systems without any protection from corrosion and they get out of order. Leakages in new houses are also not uncommon. They usually occur as a result of low-quality adjustment of the system by workers. It also important to note the absence of certain skills of plumbers, who don’t conduct the inspections of in-house systems in time. Sometimes also the residents themselves forget to keep their pipeline systems and water fittings in their apartment in good condition. Plumbers are not systematically invited for preventive examinations to detect possible leaks in the domestic plumbing. The amount of unproductive losses increases while simultaneous use of valve tenants, and at the increase of the number of residents in the building. Water leaks in the system depend on the amount of water system piping damages, and damages of other elements, for example, water valves, connections, etc. The pressure in the leak area also plays an important role.

  6. Contribution of proton leak to oxygen consumption in skeletal muscle during intense exercise is very low despite large contribution at rest.

    Directory of Open Access Journals (Sweden)

    Bernard Korzeniewski

    Full Text Available A computer model was used to simulate the dependence of protonmotive force (Δp, proton leak and phenomenological (involving proton leak ATP/O2 ratio on work intensity in skeletal muscle. Δp, NADH and proton leak decreased with work intensity. The contribution of proton leak to oxygen consumption ([Formula: see text] decreased from about 60% at rest to about 3 and 1% at moderate and heavy/severe exercise, respectively, while the ATP/O2 ratio increased from 2.1 to 5.5 and 5.7. A two-fold increase in proton leak activity or its decrease to zero decreased/increased the ATP/O2 ratio by only about 3 and 1% during moderate and heavy/severe exercise, respectively. The low contribution of proton leak to [Formula: see text] in intensively working skeletal muscle was mostly caused by a huge increase in ATP usage intensity during rest-to-work transition, while OXPHOS, and thus oxidative ATP supply and [Formula: see text] related to it, was mostly stimulated by high each-step activation (ESA of OXPHOS complexes. The contribution of proton leak to [Formula: see text] and ATP/O2 ratio in isolated mitochondria should not be directly extrapolated to working muscle, as mitochondria lack ESA, at least in the absence of Ca2+, and therefore [Formula: see text] cannot be elevated as much as in intact muscle.

  7. Internal magnetic target of proton synchrotron

    International Nuclear Information System (INIS)

    Gachurin, V.V.; Kats, M.M.; Kondrat'ev, L.N.; Rogal', A.D.; Rusinov, V.Yu.

    1988-01-01

    Proton extraction from a synchrotron by means of an internal target of magnetized iron is described. The particles that are aimed at the target pass directly through it and are deflected by the internal magnetic field of the target in the extraction direction. The general properties of magnetic targets are examined theoretically and a specific devices and results of its testing are described

  8. Study of Internal and External Leaks in Tests of Anode-Supported SOFCs

    DEFF Research Database (Denmark)

    Rasmussen, Jens Foldager Bregnballe; Hendriksen, Peter Vang; Hagen, Anke

    2008-01-01

    A planar anode-supported solid oxide fuel cell (SOFC) has been tested to investigate gas tightness of the electrolyte and the applied seals. Gas leaks reduce the efficiency of the SOFC and it is thus important to determine and minimise them. Probe gases (He and Ar) and a Quadrupole Mass Spectrome......A planar anode-supported solid oxide fuel cell (SOFC) has been tested to investigate gas tightness of the electrolyte and the applied seals. Gas leaks reduce the efficiency of the SOFC and it is thus important to determine and minimise them. Probe gases (He and Ar) and a Quadrupole Mass...... Spectrometer were used to detect both internal (through electrolyte) and external (through seals) gas leaks. The internal gas leak through the electrolyte was quantified under different conditions, as was the external leak from the surroundings to the anode. The internal gas leak did not depend on the pressure...... difference between the anode and the cathode gas compartment, and can thus be described as diffusion driven. External leaks between the surroundings and the anode, but not the cathode gas compartment was observed. They were influenced by the pressure difference and are thus driven by both concentration...

  9. Fatigue and creep to leak tests of proton exchange membranes using pressure-loaded blisters

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongqiang; Dillard, David A.; Case, Scott W. [Department of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0219 (United States); Ellis, Michael W. [Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0238 (United States); Lai, Yeh-Hung; Gittleman, Craig S.; Miller, Daniel P. [Fuel Cell Research Lab, GM R and D, General Motors Corporation, 10 Carriage Street, Honeoye Falls, NY 14472-0603 (United States)

    2009-12-01

    In this study, three commercially available proton exchange membranes (PEMs) are biaxially tested using pressure-loaded blisters to characterize their resistance to gas leakage under either static (creep) or cyclic fatigue loading. The pressurizing medium, air, is directly used for leak detection. These tests are believed to be more relevant to fuel cell applications than quasi-static uniaxial tensile-to-rupture tests because of the use of biaxial cyclic and sustained loading and the use of gas leakage as the failure criterion. They also have advantages over relative humidity cycling test, in which a bare PEM or catalyst coated membrane is clamped with gas diffusion media and flow field plates and subjected to cyclic changes in relative humidity, because of the flexibility in allowing controlled mechanical loading and accelerated testing. Nafion {sup registered} NRE-211 membranes are tested at three different temperatures and the time-temperature superposition principle is used to construct stress-lifetime master curve. Tested at 90 C, 2%RH extruded Ion Power {sup registered} N111-IP membranes have a longer lifetime than Gore trademark -Select {sup registered} 57 and Nafion {sup registered} NRE-211 membranes. (author)

  10. Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

    Science.gov (United States)

    Woronowicz, Michael; Abel, Joshua; Autrey, David; Blackmon, Rebecca; Bond, Tim; Brown, Martin; Buffington, Jesse; Cheng, Edward; DeLatte, Danielle; Garcia, Kelvin; hide

    2014-01-01

    The International Space Station program is developing a robotically-operated leak locator tool to be used externally. The tool would consist of a Residual Gas Analyzer for partial pressure measurements and a full range pressure gauge for total pressure measurements. The primary application is to detect NH3 coolant leaks in the ISS thermal control system. An analytical model of leak plume physics is presented that can account for effusive flow as well as plumes produced by sonic orifices and thruster operations. This model is used along with knowledge of typical RGA and full range gauge performance to analyze the expected instrument sensitivity to ISS leaks of various sizes and relative locations ("directionality"). The paper also presents experimental results of leak simulation testing in a large thermal vacuum chamber at NASA Goddard Space Flight Center. This test characterized instrument sensitivity as a function of leak rates ranging from 1 lb-mass/yr. to about 1 lb-mass/day. This data may represent the first measurements collected by an RGA or ion gauge system monitoring off-axis point sources as a function of location and orientation. Test results are compared to the analytical model and used to propose strategies for on-orbit leak location and environment characterization using the proposed instrument while taking into account local ISS conditions and the effects of ram/wake flows and structural shadowing within low Earth orbit.

  11. Analytical and experimental studies of leak location and environment characterization for the international space station

    Energy Technology Data Exchange (ETDEWEB)

    Woronowicz, Michael; Blackmon, Rebecca; Brown, Martin [Stinger Ghaffarian Technologies, Inc, 7701 Greenbelt Rd, Greenbelt, MD 20770 (United States); Abel, Joshua; Hawk, Doug [Alliant Techsystems, Inc, 5050 Powder Mill Road, Beltsville, Maryland 20705 (United States); Autrey, David; Glenn, Jodie [Lockheed Martin, 1300 Hercules, Houston, TX 77058 (United States); Bond, Tim; Buffington, Jesse [NASA Johnson Space Flight Center, 2101 NASA Pkwy, Houston, TX 77058 (United States); Cheng, Edward; Ma, Jonathan; Rossetti, Dino [Conceptual Analytics, 8209 Woburn Abbey Rd, Glenn Dale, MD 20769 (United States); DeLatte, Danielle [ASRC Federal Space and Defense, 7000 Muirkirk Meadows Drive, Suite 100, Beltsville, MD 20705 (United States); Garcia, Kelvin; Mohammed, Jelila; Montt de Garcia, Kristina; Perry, Radford [NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771 (United States); Tull, Kimathi [Jackson and Tull, 7375 Executive Pl, Lanham, MD 20706 (United States); Warren, Eric [Wyle STE Group, 1290 Hercules Ave, Houston, TX 77058-2769 (United States)

    2014-12-09

    The International Space Station program is developing a robotically-operated leak locator tool to be used externally. The tool would consist of a Residual Gas Analyzer for partial pressure measurements and a full range pressure gauge for total pressure measurements. The primary application is to demonstrate the ability to detect NH{sub 3} coolant leaks in the ISS thermal control system. An analytical model of leak plume physics is presented that can account for effusive flow as well as plumes produced by sonic orifices and thruster operations. This model is used along with knowledge of typical RGA and full range gauge performance to analyze the expected instrument sensitivity to ISS leaks of various sizes and relative locations (“directionality”). The paper also presents experimental results of leak simulation testing in a large thermal vacuum chamber at NASA Goddard Space Flight Center. This test characterized instrument sensitivity as a function of leak rates ranging from 1 lb{sub m/}/yr. to about 1 lb{sub m}/day. This data may represent the first measurements collected by an RGA or ion gauge system monitoring off-axis point sources as a function of location and orientation. Test results are compared to the analytical model and used to propose strategies for on-orbit leak location and environment characterization using the proposed instrument while taking into account local ISS conditions and the effects of ram/wake flows and structural shadowing within low Earth orbit.

  12. Analytical and experimental studies of leak location and environment characterization for the international space station

    International Nuclear Information System (INIS)

    Woronowicz, Michael; Blackmon, Rebecca; Brown, Martin; Abel, Joshua; Hawk, Doug; Autrey, David; Glenn, Jodie; Bond, Tim; Buffington, Jesse; Cheng, Edward; Ma, Jonathan; Rossetti, Dino; DeLatte, Danielle; Garcia, Kelvin; Mohammed, Jelila; Montt de Garcia, Kristina; Perry, Radford; Tull, Kimathi; Warren, Eric

    2014-01-01

    The International Space Station program is developing a robotically-operated leak locator tool to be used externally. The tool would consist of a Residual Gas Analyzer for partial pressure measurements and a full range pressure gauge for total pressure measurements. The primary application is to demonstrate the ability to detect NH 3 coolant leaks in the ISS thermal control system. An analytical model of leak plume physics is presented that can account for effusive flow as well as plumes produced by sonic orifices and thruster operations. This model is used along with knowledge of typical RGA and full range gauge performance to analyze the expected instrument sensitivity to ISS leaks of various sizes and relative locations (“directionality”). The paper also presents experimental results of leak simulation testing in a large thermal vacuum chamber at NASA Goddard Space Flight Center. This test characterized instrument sensitivity as a function of leak rates ranging from 1 lb m/ /yr. to about 1 lb m /day. This data may represent the first measurements collected by an RGA or ion gauge system monitoring off-axis point sources as a function of location and orientation. Test results are compared to the analytical model and used to propose strategies for on-orbit leak location and environment characterization using the proposed instrument while taking into account local ISS conditions and the effects of ram/wake flows and structural shadowing within low Earth orbit

  13. Leaks in the internal water supply piping systems

    OpenAIRE

    Orlov Evgeniy Vladimirovich; Komarov Anatoliy Sergeevich; Mel’nikov Fedor Alekseevich; Serov Aleksandr Evgen’evich

    2015-01-01

    Great water losses in the internal plumbing of a building lead to the waste of money for a fence, purification and supply of water volumes in excess. This does not support the concept of water conservation and resource saving lying today in the basis of any building’s construction having plumbing. Leakage means unplanned of water losses systems in domestic water supply systems (hot or cold) as a result of impaired integrity, complicating the operation of a system and leading to high costs of ...

  14. Hyperthyroidism stimulates mitochondrial proton leak and ATP turnover in rat hepatocytes but does not change the overall kinetics of substrate oxidation reactions.

    Science.gov (United States)

    Harper, M E; Brand, M D

    1994-08-01

    Thyroid hormones have well-known effects on oxidative phosphorylation, but there is little quantitative information on their important sites of action. We have used top-down elasticity analysis, an extension of metabolic control analysis, to identify the sites of action of thyroid hormones on oxidative phosphorylation in rat hepatocytes. We divided the oxidative phosphorylation system into three blocks of reactions: the substrate oxidation subsystem, the phosphorylating subsystem, and the mitochondrial proton leak subsystem and have identified those blocks of reactions whose kinetics are significantly changed by hyperthyroidism. Our results show significant effects on the kinetics of the proton leak and the phosphorylating subsystems. Quantitative analyses revealed that 43% of the increase in resting respiration rate in hyperthyroid hepatocytes compared with euthyroid hepatocytes was due to differences in the proton leak and 59% was due to differences in the activity of the phosphorylating subsystem. There were no significant effects on the substrate oxidation subsystem. Changes in nonmitochondrial oxygen consumption accounted for -2% of the change in respiration rate. Top-down control analysis revealed that the distribution of control over the rates of mitochondrial oxygen consumption, ATP synthesis and consumption, and proton leak and over mitochondrial membrane potential (delta psi m) was similar in hepatocytes from hyperthyroid and littermate-paired euthyroid controls. The results of this study include the first complete top-down elasticity and control analyses of oxidative phosphorylation in hepatocytes from hyperthyroid rats.

  15. Peptides containing internal residues of pyroglutamic acid: proton NMR characteristics

    International Nuclear Information System (INIS)

    Khan, S.A.

    1986-01-01

    The proton NMR characteristics of internal pyroglutamic acid (Glp; 5-oxoproline) residues in seven tripeptides of the general structure Boc-Xxx-Glp-Yyy-NH 2 were studied. In general, the chemical shifts of several diagnostic protons moved downfield on going from the Glu-containing peptides (Boc-Xxx-Glu-Yyy-NH 2 ) to the corresponding Glp-containing peptides. The C-2 proton of the Xxx residue was shifted by about 1.1 ppm. The N-2 proton of the Yyy residue was shifted by about 0.5 ppm. The C-2 proton of the Glx residue itself was shifted by about 0.5 ppm. One of the Glx C-3 protons was also shifted by about 0.5 ppm, but the other remained essentially unchanged. Finally, the Glx C-4 protons were shifted by about 0.3 ppm. Internal Glu residues are readily converted chemically into internal Glp residues. This conversion also occurs as a side reaction during HP cleavage of the protecting group from Glu(OBzl) residues. The spontaneous fragmentation of serum proteins C3, C4 and λ 2 -macroglobulin under denaturing conditions is probably due to regioselective hydrolysis of an internal Glp residue formed in each of these proteins upon denaturation. These proton NMR characteristics may be useful in establishing the presence of internal Glp residues in synthetic and natural peptides

  16. The effects of fasting and cold exposure on metabolic rate and mitochondrial proton leak in liver and skeletal muscle of an amphibian, the cane toad Bufo marinus.

    Science.gov (United States)

    Trzcionka, M; Withers, K W; Klingenspor, M; Jastroch, M

    2008-06-01

    Futile cycling of protons across the mitochondrial inner membrane contributes significantly to standard metabolic rate in a variety of ectothermic and endothermic animals, but adaptations of the mitochondrial bioenergetics to different environmental conditions have rarely been studied in ectotherms. Changes in ambient temperature and nutritional status have a great effect on the physiological demands of ectothermic amphibians and may require the adjustment of mitochondrial efficiency. In order to investigate the effect of temperature and nutritional status on the mitochondrial level, we exposed male cane toads to either 10 degrees C or 30 degrees C and fasted half of the animals in each group. Cold exposure resulted in a fourfold reduction of the resting metabolic rate whereas nutritional status had only minor effects. The mitochondrial adjustments to each condition were observed by comparing the proton leak kinetics of isolated liver and skeletal muscle mitochondria at 25 degrees C. In response to cold exposure, liver mitochondria showed a decrease in proton conductance while skeletal muscle mitochondria were unchanged. Additional food deprivation had minor effects in skeletal muscle, but in liver we uncovered surprising differences in energy saving mechanisms between the acclimation temperatures: in warm-acclimated toads, fasting resulted in a decrease of the proton conductance whereas in cold-acclimated toads, the activity of the respiratory chain was reduced. To investigate the molecular mechanism underlying mitochondrial proton leakage, we determined the adenine-nucleotide transporter (ANT) content, which explained tissue-specific differences in the basal proton leak, but neither the ANT nor uncoupling protein (UCP) gene expression correlated with alterations of the proton leak in response to physiological stimuli.

  17. Adaptive plasticity of skeletal muscle energetics in hibernating frogs: mitochondrial proton leak during metabolic depression.

    Science.gov (United States)

    Boutilier, Robert G; St-Pierre, Julie

    2002-08-01

    The common frog (Rana temporaria) spends the coldest months of each year overwintering in ice-covered ponds where temperatures can vary from 0.5 to 4.0 degrees C. Over the course of a winter season, the animals enter progressively into a state of metabolic depression that relies almost exclusively on aerobic production of ATP. However, if aerobic metabolism is threatened, for example by increasingly hypoxic conditions, decreases in the animal's metabolic rate can reach upwards of 75% compared with the 50% decrease seen during normoxia. Under these conditions, the major proportion of the overall reduction in whole-animal metabolic rate can be accounted for by metabolic suppression of the skeletal muscle (which makes up approximately 40% of body mass). Little is known about the properties of mitochondria during prolonged periods of metabolic depression, so we have examined several aspects of mitochondrial metabolism in the skeletal muscle of frogs over periods of hibernation of up to 4 months. Mitochondria isolated from the skeletal muscle of frogs hibernating in hypoxic water show a considerable reorganisation of function compared with those isolated from normoxic submerged animals at the same temperature (3 degrees C). Both the active (state 3) and resting (state 4) respiration rates of mitochondria decrease during hypoxic, but not normoxic, hibernation. In addition, the affinity of mitochondria for oxygen increases during periods of acute hypoxic stress during normoxic hibernation as well as during long-term hibernation in hypoxic water. The decrease in mitochondrial state 4 respiration rates during hypoxic hibernation evidently occurs through a reduction in electron-transport chain activity, not through a lowered proton conductance of the mitochondrial inner membrane. The reduced aerobic capacity of frog skeletal muscle during hypoxic hibernation is accompanied by lowered activities of key enzymes of mitochondrial metabolism caused by changes in the intrinsic

  18. A study on the spectrum analyzing of internal leak in valve for power plant using acoustic emission method

    International Nuclear Information System (INIS)

    Lee, Sang Guk; Lee, Sun Ki; Lee, Jun Shin; Sohn, Seok Man

    2004-01-01

    The purpose of this study is to estimate the availability of acoustic emission method to the internal leak of the valves at nuclear power plants. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. From the comparison of the background noise data with the experimental results as to relation between leak flow and acoustic signal, the minimum leak flow rates that can be detected by acoustic signal was suggested. When the background levels are higher than the acoustic signal, the method described below was considered that the analysis the remainder among the background noise frequency spectrum and the acoustic signal spectrum become a very useful leak detection method. A few experimental examples of the spectrum analysis that varied the background noise characteristic were given

  19. Impacts of an Ammonia Leak on the Cabin Atmosphere of the International Space Station

    Science.gov (United States)

    Duchesne, Stephanie M.; Sweterlitsch, Jeffrey J.; Son, Chang H.; Perry Jay L.

    2012-01-01

    Toxic chemical release into the cabin atmosphere is one of the three major emergency scenarios identified on the International Space Station (ISS). The release of anhydrous ammonia, the coolant used in the U.S. On-orbit Segment (USOS) External Active Thermal Control Subsystem (EATCS), into the ISS cabin atmosphere is one of the most serious toxic chemical release cases identified on board ISS. The USOS Thermal Control System (TCS) includes an Internal Thermal Control Subsystem (ITCS) water loop and an EATCS ammonia loop that transfer heat at the interface heat exchanger (IFHX). Failure modes exist that could cause a breach within the IFHX. This breach would result in high pressure ammonia from the EATCS flowing into the lower pressure ITCS water loop. As the pressure builds in the ITCS loop, it is likely that the gas trap, which has the lowest maximum design pressure within the ITCS, would burst and cause ammonia to enter the ISS atmosphere. It is crucial to first characterize the release of ammonia into the ISS atmosphere in order to develop methods to properly mitigate the environmental risk. This paper will document the methods used to characterize an ammonia leak into the ISS cabin atmosphere. A mathematical model of the leak was first developed in order to define the flow of ammonia into the ISS cabin atmosphere based on a series of IFHX rupture cases. Computational Fluid Dynamics (CFD) methods were then used to model the dispersion of the ammonia throughout the ISS cabin and determine localized effects and ventilation effects on the dispersion of ammonia. Lastly, the capabilities of the current on-orbit systems to remove ammonia were reviewed and scrubbing rates of the ISS systems were defined based on the ammonia release models. With this full characterization of the release of ammonia from the USOS TCS, an appropriate mitigation strategy that includes crew and system emergency response procedures, personal protection equipment use, and atmosphere monitoring

  20. Proceedings of the first international summit on intestinal anastomotic leak, Chicago, Illinois, October 4-5, 2012

    NARCIS (Netherlands)

    Shogan, B.D.; An, G.C.; Schardey, H.M.; Matthews, J.B.; Umanskiy, K.; Fleshman, J.W.; Hoeppner, J.; Fry, D.E.; Garcia-Granereo, E.; Jeekel, H.; Goor, H. van; Dellinger, E.P.; Konda, V.; Gilbert, J.A.; Auner, G.W.; Alverdy, J.C.

    2014-01-01

    OBJECTIVE: The first international summit on anastomotic leak was held in Chicago in October, 2012 to assess current knowledge in the field and develop novel lines of inquiry. The following report is a summary of the proceedings with commentaries and future prospects for clinical trials and

  1. Preliminary design of the new Proton Synchrotron Internal Dump core

    CERN Document Server

    AUTHOR|(CDS)2091975; Nuiry, François-Xavier

    The luminosity of the LHC particle accelerator at CERN is planned to be upgraded in the first half of 2020s, requiring also the upgrade of its injector accelerators, including the Proton Synchrotron (PS). The PS Internal Dumps are beam dumps located in the PS accelerator ring. They are safety devices designed to stop the circulating proton beam in order to protect the accelerator from damage due to an uncontrolled beam loss. The PS Internal Dumps need to be upgraded to be able to withstand the future higher intensity and energy proton beams. The dump core is a block of material interacting with the beam. It is located in ultra-high vacuum and moved into the beam path in 150 milliseconds by an electromagnet and spring-based actuation mechanism. The circulating proton beam is shaved by the core surface during thousands of beam revolutions. The preliminary new dump core design weighs 13 kilograms and consists of an isostatically pressed fine-grain graphite and a precipitation hardened copper alloy CuCrZr. The ...

  2. Test of internal halo targets in the HERA proton ring

    International Nuclear Information System (INIS)

    Hast, C.; Hofmann, W.; Khan, S.; Knoepfle, K.T.; Reber, M.; Rieling, J.; Spahn, M.; Spengler, J.; Lohse, T.; Pugatch, V.

    1995-01-01

    Internal wire targets in the halo of stored proton beams provide a line source of proton-nucleus interactions for highest-rate fixed target experiments. We have studied such internal halo targets at the 820 GeV proton ring of the HERA ep collider. The tests showed that most of the protons in the beam halo - which would otherwise hit the collimators - can be brought to interaction in a relatively thin target wire at distances of 7 to 8 beam widths from the center of the beam. At less than 10% of the HERA total design current, and less than 20% of the current per bunch, interaction rates up to 8 MHz were observed, corresponding to more than 2 interactions per bunch crossing. The halo targets were used in parallel to the HERA luminosity operation; no significant disturbances of the HERA ep experiments, of the machine stability or beam quality were observed. We present data on the steady-state and transient behaviour of interaction rates and discuss the interpretation in terms of a simple beam dynamics model. Issues of short-, medium- and long-term rate fluctuations and of rate stabilization by feedback are addressed. ((orig.))

  3. Test of internal halo targets in the HERA proton ring

    International Nuclear Information System (INIS)

    Hast, C.; Hofmann, W.; Khan, S.; Knoepfle, K.T.; Reber, M.; Rieling, J.; Spahn, M.; Spengler, J.; Lohse, T.; Pugatch, V.

    1994-07-01

    Internal wire targets in the halo of stored proton beams provide a line source of proton-nucleus interactions for highest-rate fixed target experiments. We have studied such internal halo targets at the 820 GeV proton ring of the HERA ep collider. The tests showed that most of the protons in the beam halo - which would otherwise hit the collimators - can be brought to interaction in a relatively thin target wire at distances of 7 to 8 beam widths from the center of the beam. At less than 10% of the HERA total design current, and less than 20% of the current per bunch, interaction rates up to 8 MHz were observed, corresponding to more than 2 interactions per bunch crossing. The halo targets were used in parallel to the HERA luminosity operation; no significant disturbances of the HERA ep experiments, of the machine stability or beam quality were observed. We present data on the steady-state and transient behaviour of interaction rates and discuss the interpretation in terms of a simple beam dynamics model. Issues of short-, medium- and long-term rate fluctuations and of rate stabilization by feedback are addressed. (orig.)

  4. The Membrane Modulates Internal Proton Transfer in Cytochrome c Oxidase

    DEFF Research Database (Denmark)

    Öjemyr, Linda Nasvik; Ballmoos, Christoph von; Faxén, Kristina

    2012-01-01

    The functionality of membrane proteins is often modulated by the surrounding membrane. Here, we investigated the effect of membrane reconstitution of purified cytochrome c oxidase (CytcO) on the kinetics and thermodynamics of internal electron and proton-transfer reactions during O-2 reduction...... DOPC lipids. In conclusion, the data show that the membrane significantly modulates internal charge-transfer reactions and thereby the function of the membrane-bound enzyme.......-glycerol) (DOPG). In addition, a small Change in the internal Cu-A-heme a electron equilibrium constant was observed. This effect was lipid-dependent and explained in terms of a lower electrostatic potential within the membrane-spanning part of the protein with the anionic DOPG lipids than with the zwitterionic...

  5. Internal humidifying of PEM [Proton Exchange Membrane] fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Staschewski, D [Karlsruhe Research Center (FZK), Karlsruhe (Germany). Inst. for Neutron Physics and Reactor Technics

    1996-12-01

    Hydrogen fuel cells (FC) for vehicular traction should stand out for a car-specific lightweight design. As regards PEMFC systems containing proton exchange membranes, this quality can be considerably improved by introducing porous bipolar plates which are conditioned by a water loop and deliver hot humidifying water to the adjacent membrane-electrode assembly (MEA). According to the principle of internal humidification here indicated special fuel cells based on sintered fiber and powder graphite were manufactured at FZK on a semi-technical scale. Self-made Pt/C electrodes hotpressed onto Nafion resulted in currents up to 200 A with pure oxygen as oxidant, providing the precondition for detailed studies of turnover and drainage rates within a monocell test arrangement. (author)

  6. Radiobiology of Proton Therapy - Results of an international expert workshop

    DEFF Research Database (Denmark)

    Lühr, Armin; von Neubeck, Cläre; Pawelke, Jörg

    2018-01-01

    The physical properties of proton beams offer the potential to reduce toxicity in tumor-adjacent normal tissues. Toward this end, the number of proton radiotherapy facilities has steeply increased over the last 10-15 years to currently around 70 operational centers worldwide. However, taking full...... in proton therapy combined with systemic treatments, and (4) testing biological effects of protons in clinical trials. Finally, important research avenues for improvement of proton radiotherapy based on radiobiological knowledge are identified. The clinical distribution of radiobiological effectiveness...... of protons alone or in combination with systemic chemo- or immunotherapies as well as patient stratification based on biomarker expressions are key to reach the full potential of proton beam therapy. Dedicated preclinical experiments, innovative clinical trial designs, and large high-quality data...

  7. A study of the internal spin structure of the proton through polarized deep inelastic muon-proton scattering

    International Nuclear Information System (INIS)

    Piegaia, R.N.

    1988-01-01

    This thesis presents a study of the internal spin structure of the proton through the measurement performed by the European Muon Collaboration, EMC, at the European Center for Nuclear Research, CERN, of the spin asymmetry in the deep-inelastic scattering of longitudinally polarized muons by longitudinally polarized protons. The data obtained considerably extend the kinematic range covered by a previous lower-energy polarized electron-proton scattering experiment. Although the results were found to be in agreement in the region of overlap, the study of the low x range (0.01 1 p was computed and found to be in disagreement with the Ellis-Jaffe sum rule. The result seems to indicate that only a small fraction of the proton spin originates from the spins of the quarks

  8. Spill or leak? Carbon leakage with international technology spillovers : A CGE analysis

    NARCIS (Netherlands)

    Gerlagh, R.; Kuik, O.

    This paper studies the effect of endogenous technical change and international technology spillovers on carbon leakage. It is well known that a unilateral CO2 abatement policy in one region may cause CO2 emissions to increase in non-abating regions because of the relocation of CO2-intensive firms

  9. Enhanced relative biological effectiveness of proton radiotherapy in tumor cells with internalized gold nanoparticles

    International Nuclear Information System (INIS)

    Polf, Jerimy C.; Gillin, Michael; Bronk, Lawrence F.; Driessen, Wouter H. P.; Arap, Wadih; Pasqualini, Renata

    2011-01-01

    The development and use of sensitizing agents to improve the effectiveness of radiotherapy have long been sought to improve our ability to treat cancer. In this letter, we have studied the relative biological effectiveness of proton beam radiotherapy on prostate tumor cells with and without internalized gold nanoparticles. The effectiveness of proton radiotherapy for the killing of prostate tumor cells was increased by approximately 15%-20% for those cells containing internalized gold nanoparticles.

  10. Enhanced relative biological effectiveness of proton radiotherapy in tumor cells with internalized gold nanoparticles

    Science.gov (United States)

    Polf, Jerimy C.; Bronk, Lawrence F.; Driessen, Wouter H. P.; Arap, Wadih; Pasqualini, Renata; Gillin, Michael

    2011-01-01

    The development and use of sensitizing agents to improve the effectiveness of radiotherapy have long been sought to improve our ability to treat cancer. In this letter, we have studied the relative biological effectiveness of proton beam radiotherapy on prostate tumor cells with and without internalized gold nanoparticles. The effectiveness of proton radiotherapy for the killing of prostate tumor cells was increased by approximately 15%–20% for those cells containing internalized gold nanoparticles. PMID:21915155

  11. Numerical Study of Ammonia Leak and Dispersion in the International Space Station

    Science.gov (United States)

    Son, Chang H.

    2012-01-01

    Release of ammonia into the International Space Station (ISS) cabin atmosphere can occur if the water/ammonia barrier breach of the active thermal control system (ATCS) interface heat exchanger (IFHX) happens. After IFHX breach liquid ammonia is introduced into the water-filled internal thermal control system (ITCS) and then to the cabin environment through a ruptured gas trap. Once the liquid water/ammonia mixture exits ITCS, it instantly vaporizes and mixes with the U.S. Laboratory cabin air that results in rapid deterioration of the cabin conditions. The goal of the study is to assess ammonia propagation in the Station after IFHX breach to plan the operation procedure. A Computational Fluid Dynamics (CFD) model for accurate prediction of airflow and ammonia transport within each of the modules in the ISS cabin was developed. CFD data on ammonia content in the cabin aisle way of the ISS and, in particular, in the Russian On- Orbit Segment during the period of 15 minutes after gas trap rupture are presented for four scenarios of rupture response. Localized effects of ammonia dispersion and risk mitigation are discussed.

  12. Investigations of leak opening and outflow behaviour on straight pipes with circumferential cracks with internal pressure and bending load

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1989-01-01

    The experiments carried out so far on straight pipes with circumferential cracks and results of subsequent calculations from this experiment are introduced. The subsequent calculations are not yet completed at all points. From the experiments one can record that the selected crack sizes and stresses have guaranteed stable crack behaviour in all cases. The comparison of experimental and calculated crack openings shows satisfactory agreement (difference about 20% for experiment E22.03. The compared leak rates show differences of up to about 50% (in isolated cases even more). For small leak rates (0.01 to 0.1 kg/sec), one can expect a difference of about 100% between calculation and experiment. For medium leak rates, we regard a maximum difference of about 30% as achievable. For large leak rates, the achievable accuracy plays no part for the detectability. (orig./DG) [de

  13. Ammonia Leak Locator Study

    Science.gov (United States)

    Dodge, Franklin T.; Wuest, Martin P.; Deffenbaugh, Danny M.

    1995-01-01

    The thermal control system of International Space Station Alpha will use liquid ammonia as the heat exchange fluid. It is expected that small leaks (of the order perhaps of one pound of ammonia per day) may develop in the lines transporting the ammonia to the various facilities as well as in the heat exchange equipment. Such leaks must be detected and located before the supply of ammonia becomes critically low. For that reason, NASA-JSC has a program underway to evaluate instruments that can detect and locate ultra-small concentrations of ammonia in a high vacuum environment. To be useful, the instrument must be portable and small enough that an astronaut can easily handle it during extravehicular activity. An additional complication in the design of the instrument is that the environment immediately surrounding ISSA will contain small concentrations of many other gases from venting of onboard experiments as well as from other kinds of leaks. These other vapors include water, cabin air, CO2, CO, argon, N2, and ethylene glycol. Altogether, this local environment might have a pressure of the order of 10(exp -7) to 10(exp -6) torr. Southwest Research Institute (SwRI) was contracted by NASA-JSC to provide support to NASA-JSC and its prime contractors in evaluating ammonia-location instruments and to make a preliminary trade study of the advantages and limitations of potential instruments. The present effort builds upon an earlier SwRI study to evaluate ammonia leak detection instruments [Jolly and Deffenbaugh]. The objectives of the present effort include: (1) Estimate the characteristics of representative ammonia leaks; (2) Evaluate the baseline instrument in the light of the estimated ammonia leak characteristics; (3) Propose alternative instrument concepts; and (4) Conduct a trade study of the proposed alternative concepts and recommend promising instruments. The baseline leak-location instrument selected by NASA-JSC was an ion gauge.

  14. Internal validation of the renal pelvic score: a novel marker of renal pelvic anatomy that predicts urine leak after partial nephrectomy.

    Science.gov (United States)

    Tomaszewski, Jeffrey J; Smaldone, Marc C; Cung, Bic; Li, Tianyu; Mehrazin, Reza; Kutikov, Alexander; Canter, Daniel J; Viterbo, Rosalia; Chen, David Y T; Greenberg, Richard E; Uzzo, Robert G

    2014-08-01

    To internally validate the renal pelvic score (RPS) in an expanded cohort of patients undergoing partial nephrectomy (PN). Our prospective institutional renal cell carcinoma database was used to identify all patients undergoing PN for localized renal cell carcinoma from 2007 to 2013. Patients were classified by RPS as having an intraparenchymal or extraparenchymal renal pelvis. Multivariate logistic regression models were used to examine the relationship between RPS and urine leak. Eight hundred thirty-one patients (median age, 60 ± 11.6 years; 65.1% male) undergoing PN (57.3% robotic) for low (28.9%), intermediate (56.5%), and high complexity (14.5%) localized renal tumors (median size, 3.0 ± 2.3 cm; median nephrometry score, 7.0 ± 2.6) were included. Fifty-four patients (6.5%) developed a clinically significant or radiographically identified urine leak. Seventy-two of 831 renal pelvises (8.7%) were classified as intraparenchymal. Intrarenal pelvic anatomy was associated with a markedly increased risk of urine leak (43.1% vs 3.0%; P renal pelvis; odds ratio [OR], 24.8; confidence interval [CI], 11.5-53.4; P Renal pelvic anatomy as measured by the RPS best predicts urine leak after open and robotic partial nephrectomy. Although external validation of the RPS is required, preoperative identification of patients at increased risk for urine leak should be considered in perioperative management and counseling algorithms. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. SEALING SIMULATED LEAKS

    Energy Technology Data Exchange (ETDEWEB)

    Michael A. Romano

    2004-09-01

    This report details the testing equipment, procedures and results performed under Task 7.2 Sealing Simulated Leaks. In terms of our ability to seal leaks identified in the technical topical report, Analysis of Current Field Data, we were 100% successful. In regards to maintaining seal integrity after pigging operations we achieved varying degrees of success. Internal Corrosion defects proved to be the most resistant to the effects of pigging while External Corrosion proved to be the least resistant. Overall, with limitations, pressure activated sealant technology would be a viable option under the right circumstances.

  16. SU-E-T-542: Measurement of Internal Neutrons for Uniform Scanning Proton Beams

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M; Ahmad, S [University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Zheng, Y; Rana, S [Procure Proton Therapy Center, Oklahoma City, OK (United States); Collums, T [University of Iowa Hospitals and Clinics, Iowa City, IA (United States); Monsoon, J; Benton, E [Oklahoma State University, Stillwater, OK (United States)

    2015-06-15

    Purpose: In proton radiotherapy, the production of neutrons is a wellknown problem since neutron exposure can lead to increased risk of secondary cancers later in the patient’s lifetime. The assessment of neutron exposure is, therefore, important for the overall quality of proton radiotherapy. This study investigates the secondary neutrons created inside the patient from uniform scanning proton beams. Methods: Dose equivalent due to secondary neutrons was measured outside the primary field as a function of distance from beam isocenter at three different angles, 45, 90 and 135 degree, relative to beam axis. Plastic track nuclear detector (CR-39 PNTD) was used for the measurement of neutron dose. Two experimental configurations, in-air and cylindrical-phantom, were designed. In a cylindrical-phantom configuration, a cylindrical phantom of 5.5 cm diameter and 35 cm long was placed along the beam direction and in an in-air configuration, no phantom was used. All the detectors were placed at nearly identical locations in both configurations. Three proton beams of range 5 cm, 18 cm, and 32 cm with 4 cm modulation width and a 5 cm diameter aperture were used. The contribution from internal neutrons was estimated from the differences in measured dose equivalent between in-air and cylindrical-phantom configurations at respective locations. Results: The measured ratio of neutron dose equivalent to the primary proton dose (H/D) dropped off with distance and ranged from 27 to 0.3 mSv/Gy. The contribution of internal neutrons near the treatment field edge was found to be up to 64 % of the total neutron exposure. As the distance from the field edge became larger, the external neutrons from the nozzle appear to dominate and the internal neutrons became less prominent. Conclusion: This study suggests that the contribution of internal neutrons could be significant to the total neutron dose equivalent.

  17. Radiation tests of the EMU spacesuit for the International SpaceStation using energetic protons

    Energy Technology Data Exchange (ETDEWEB)

    Zeitlin, C.; Heilbronn, L.; Miller, J.; Shavers, M.

    2001-06-04

    Measurements using silicon detectors to characterize theradiation transmitted through the EMU spacesuit and a human phantom havebeen performed using 155 and 250 MeV proton beams at the Loma LindaUniversity Medical Center (LLUMC). The beams simulate radiationencountered in space, where trapped protons having kinetic energies onthe order of 100 MeV are copious. Protons with 100 MeV kinetic energy andabove can penetrate many centimeters of water of other light materials,so that astronauts exposed to such energetic particles will receive dosesto their internal organs. This dose can be enhanced or reduced byshielding - either from the spacesuit or the self-shielding of the body -but minimization of the risk depends on details of the incident particleflux (in particular the energy spectrum) and on the dose responses of thevarious critical organs.

  18. Promoting International Cooperation and Public Acceptance in Utilizing Proton Accelerator Technology

    International Nuclear Information System (INIS)

    Choi, Byung Ho; Hahn, Bong Oh; Lee, Jae Hyung; Kim, Kyu Ryung; Joo, Po Kook; Kim, In Kyu; Kim, Hyun Joon; Noh, Seung Jeong

    2002-11-01

    Proton engineering's main tool will be a high power proton accelerator which is to be established within next 10 years in the frame of Proton engineering Frontier Project. It is necessary for public to understand the meaning and importance of the project so that Project activities such as site preparation can be efficiently completed. And, it is required to establish a sound plan of international cooperation, and to develop user program to establish domestic foundation in utilizing the accelerator. Along with public relations activities through newspapers and broadcasting, there were more than 20 times of project presentations requested by various local governments, universities, and scientific societies. which resulted in strong support of the project from various societies. Based on collected information through actual visits to and internet surveys on foreign accelerators, a recommendation of international cooperation scheme has been made to complement domestic technological weak points, and there were discussions with some foreign organizations for that purpose. Especially, KEK of Japan, IHEP of China and KAERI have been deliberating on planning detail cooperation programs in developing and utilizing accelerator among 3 countries Some research items related with NT/BT/IT and utilizing proton beam were planned to be implemented in the Project. And a user program implemented in the Project In order to be prepared for future use of the accelerator. In order to upbring junior researchers for future days, an accelerator summer school has been planned to be held annually inviting prominent foreign and domestic lecturers

  19. Leak rate models and leak detection

    International Nuclear Information System (INIS)

    1992-01-01

    Leak detection may be carried out by a number of detection systems, but selection of the systems must be carefully adapted to the fluid state and the location of the leak in the reactor coolant system. Computer programs for the calculation of leak rates contain different models to take into account the fluid state before its entrance into the crack, and they have to be verified by experiments; agreement between experiments and calculations is generally not satisfactory for very small leak rates resulting from narrow cracks or from a closing bending moment

  20. Application of International Linear Collider superconducting cavities for acceleration of protons

    Directory of Open Access Journals (Sweden)

    P. N. Ostroumov

    2007-12-01

    Full Text Available Beam acceleration in the International Linear Collider (ILC will be provided by 9-cell 1300 MHz superconducting (SC cavities. The cavities are designed for effective acceleration of charged particles moving with the speed of light and are operated on π-mode to provide a maximum accelerating gradient. A significant research and development effort has been devoted to develop ILC SC technology and its rf system which resulted in excellent performance of ILC cavities. Therefore, the proposed 8-GeV proton driver in Fermilab is based on ILC cavities above ∼1.2  GeV. The efficiency of proton beam acceleration by ILC cavities drops fast for lower velocities and it was proposed to develop squeezed ILC-type (S-ILC cavities operating at 1300 MHz and designed for β_{G}=0.81, geometrical beta, to accelerate protons or H^{-} from ∼420  MeV to 1.2 GeV. This paper discusses the possibility of avoiding the development of new β_{G}=0.81 cavities by operating ILC cavities on 8/9π-mode of standing wave oscillations.

  1. Practice Patterns Analysis of Ocular Proton Therapy Centers: The International OPTIC Survey

    International Nuclear Information System (INIS)

    Hrbacek, Jan; Mishra, Kavita K.; Kacperek, Andrzej; Dendale, Remi; Nauraye, Catherine; Auger, Michel; Herault, Joel; Daftari, Inder K.; Trofimov, Alexei V.; Shih, Helen A.; Chen, Yen-Lin E.; Denker, Andrea; Heufelder, Jens; Horwacik, Tomasz; Swakoń, Jan; Hoehr, Cornelia; Duzenli, Cheryl; Pica, Alessia; Goudjil, Farid; Mazal, Alejandro

    2016-01-01

    Purpose: To assess the planning, treatment, and follow-up strategies worldwide in dedicated proton therapy ocular programs. Methods and Materials: Ten centers from 7 countries completed a questionnaire survey with 109 queries on the eye treatment planning system (TPS), hardware/software equipment, image acquisition/registration, patient positioning, eye surveillance, beam delivery, quality assurance (QA), clinical management, and workflow. Results: Worldwide, 28,891 eye patients were treated with protons at the 10 centers as of the end of 2014. Most centers treated a vast number of ocular patients (1729 to 6369). Three centers treated fewer than 200 ocular patients. Most commonly, the centers treated uveal melanoma (UM) and other primary ocular malignancies, benign ocular tumors, conjunctival lesions, choroidal metastases, and retinoblastomas. The UM dose fractionation was generally within a standard range, whereas dosing for other ocular conditions was not standardized. The majority (80%) of centers used in common a specific ocular TPS. Variability existed in imaging registration, with magnetic resonance imaging (MRI) rarely being used in routine planning (20%). Increased patient to full-time equivalent ratios were observed by higher accruing centers (P=.0161). Generally, ophthalmologists followed up the post–radiation therapy patients, though in 40% of centers radiation oncologists also followed up the patients. Seven centers had a prospective outcomes database. All centers used a cyclotron to accelerate protons with dedicated horizontal beam lines only. QA checks (range, modulation) varied substantially across centers. Conclusions: The first worldwide multi-institutional ophthalmic proton therapy survey of the clinical and technical approach shows areas of substantial overlap and areas of progress needed to achieve sustainable and systematic management. Future international efforts include research and development for imaging and planning software upgrades

  2. Practice Patterns Analysis of Ocular Proton Therapy Centers: The International OPTIC Survey

    Energy Technology Data Exchange (ETDEWEB)

    Hrbacek, Jan, E-mail: Jan.hrbacek@psi.ch [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Mishra, Kavita K. [Ocular Tumor Proton Therapy Program, University of California San Francisco, San Francisco, California (United States); Kacperek, Andrzej [National Proton Therapy Centre, Clatterbridge Cancer Centre, Bebington (United Kingdom); Dendale, Remi; Nauraye, Catherine; Auger, Michel [Centre de Protonthérapie d' Orsay, Institut Curie, Orsay (France); Herault, Joel [Centre Lacassagne, Nice (France); Daftari, Inder K. [Ocular Tumor Proton Therapy Program, University of California San Francisco, San Francisco, California (United States); Trofimov, Alexei V.; Shih, Helen A.; Chen, Yen-Lin E. [F. H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Denker, Andrea [Protons for Therapy, Helmholtz-Zentrum Berlin, Berlin (Germany); Heufelder, Jens [BerlinProtonen am HZB, Charité – Universitätsmedizin Berlin, Berlin (Germany); Horwacik, Tomasz; Swakoń, Jan [Institute of Nuclear Physic, Polish Academy of Sciences, Krakow (Poland); Hoehr, Cornelia; Duzenli, Cheryl [BC Cancer Agency – TRIUMF, Vancouver (Canada); Pica, Alessia [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Goudjil, Farid; Mazal, Alejandro [Centre de Protonthérapie d' Orsay, Institut Curie, Orsay (France); and others

    2016-05-01

    Purpose: To assess the planning, treatment, and follow-up strategies worldwide in dedicated proton therapy ocular programs. Methods and Materials: Ten centers from 7 countries completed a questionnaire survey with 109 queries on the eye treatment planning system (TPS), hardware/software equipment, image acquisition/registration, patient positioning, eye surveillance, beam delivery, quality assurance (QA), clinical management, and workflow. Results: Worldwide, 28,891 eye patients were treated with protons at the 10 centers as of the end of 2014. Most centers treated a vast number of ocular patients (1729 to 6369). Three centers treated fewer than 200 ocular patients. Most commonly, the centers treated uveal melanoma (UM) and other primary ocular malignancies, benign ocular tumors, conjunctival lesions, choroidal metastases, and retinoblastomas. The UM dose fractionation was generally within a standard range, whereas dosing for other ocular conditions was not standardized. The majority (80%) of centers used in common a specific ocular TPS. Variability existed in imaging registration, with magnetic resonance imaging (MRI) rarely being used in routine planning (20%). Increased patient to full-time equivalent ratios were observed by higher accruing centers (P=.0161). Generally, ophthalmologists followed up the post–radiation therapy patients, though in 40% of centers radiation oncologists also followed up the patients. Seven centers had a prospective outcomes database. All centers used a cyclotron to accelerate protons with dedicated horizontal beam lines only. QA checks (range, modulation) varied substantially across centers. Conclusions: The first worldwide multi-institutional ophthalmic proton therapy survey of the clinical and technical approach shows areas of substantial overlap and areas of progress needed to achieve sustainable and systematic management. Future international efforts include research and development for imaging and planning software upgrades

  3. Localization of a sound source in in a guided medium and reverberating field. Contribution to a study on leak localization in the internal wall of containment of a nuclear reactor in the case of a severe reactor accident

    International Nuclear Information System (INIS)

    Thomann, F.

    1996-01-01

    Basic data necessary for the localization of a leak in the internal wall of the containment are presented by studying the sound generated by gas jets coming out of (leaking fissures) as well as propagation in a guided medium. The results acquired have led us to choose the simple intercorrelation method and the matched filed processing method, both of which are likely to adequately handle our problems. Whereas the intercorrelation method appears to be limited in scope when dealing in the guided medium, the matched field processing is suited to leak localization over a surface of approximately 1000 m 2 (for a total surface of 10 000 m 2 ). Preliminary studies on the leak signal and on replicated signals have led us to limit the frequency band to 2600 - 3000 Hz. We have succeeded in locating a leak situated in an ordinary position with a minimum amount of replicated signals and basic data. We have improved on the estimation of Bartlett and MVDE (minimum variance distortion less filter) rendering them even more effective. Afterwards, we considered the severe accident situation and showed that the system can be installed in situ. (author)

  4. Sensors for Fluid Leak Detection

    Directory of Open Access Journals (Sweden)

    Gonzalo Pajares Martinsanz

    2015-02-01

    Full Text Available Fluid leak detection represents a problem that has attracted the interest of researchers, but not exclusively because in industries and services leaks are frequently common. Indeed, in water or gas supplies, chemical or thermal plants, sea-lines or cooling/heating systems leakage rates can cause important economic losses and sometimes, what it is more relevant, environmental pollution with human, animal or plant lives at risk. This last issue has led to increased national and international regulations with different degrees of severity regarding environmental conservation.[...

  5. A study of the internal spin structure of the proton through inclusive and semi-inclusive polarized deep-inelastic muon-proton scattering

    International Nuclear Information System (INIS)

    Papavassiliou, V.

    1988-01-01

    The internal spin structure of the proton was studied in a deep-inelastic scattering experiment a CERN, the European Laboratory for Nuclear Research, by the European Muon Collaboration, using a longitudinally polarized muon beam and a longitudinally polarized target at irradiated ammonia. The spin asymmetry was studied as a function of the Bjorken scaling variable x and the results were in agreement over the region of overlap with previous experiments that used lower-energy polarized electron beams. The higher energies of the experiment allowed to study with precision the previously unexplored region of x below 0.1 and to compute the integral of the spin-dependent structure function g 1 of the proton. This integral was found to be in disagreement with the Ellis-Jaffe sum rule which could imply either a breakdown of the SU(3) symmetry in the decays of the members of the baryon octet or a significant polarization of the strange-quark sea of the proton opposite to the proton spin. In either case and assuming the validity of the Bjorken sum rule that relates the integrals of the spin-dependent structure functions of the proton and the neutron, the total helicity of all the quarks is found to account for only a small fraction of the proton helicity. In addition, spin asymmetries in the semi-inclusive reactions where a hadron of definite sign is observed in the final state were studied. The results are consistent with the down quarks being polarized opposite to the proton spin, as expected by symmetry arguments. Implication of the results on different areas in particle physics are presented. Some future prospects for spin physics are discussed and predictions are given for deep-inelastic-scattering experiments on polarized deuterium targets and the spin structure of the neutron

  6. Leak detection : Principles and practice

    International Nuclear Information System (INIS)

    Rama Rao, V.V.K.

    1981-01-01

    Principles of leak detection are explained and various aspects of leak detection techniques and leak detectors are reviewed. The review covers: units for leaks and leak tightness, classification of leaks, timing of leak testing, designing for ease of leak testing of any job, methods of leak detection, their ranges of application and limitations, leak detectors, response time of leak test, minimum detectable concentration of search gas during leak tests, and validity of leak tests. Helium mass spectrometer type leak detector and technique are described in detail. Recent improvements in leak detectors and techniques, particularly mass spectrometer leak detectors using gases other than helium (e.g. hydrogen, argon) are also covered in the review. (M.G.B.)

  7. Dynamic pressure measures for long pipeline leak detection

    Energy Technology Data Exchange (ETDEWEB)

    Likun Wang; Hongchao Wang; Min Xiong; Bin Xu; Dongjie Tan; Hengzhang Zhou [PetroChina Pipeline Company, Langfang (China). R and D Center

    2009-07-01

    Pipeline leak detection method based on dynamic pressure is studied. The feature of dynamic pressure which is generated by the leakage of pipeline is analyzed. The dynamic pressure method is compared with the static pressure method for the advantages and disadvantages in pipeline leak detection. The dynamic pressure signal is suitable for pipeline leak detection for quick-change of pipeline internal pressure. Field tests show that the dynamic pressure method detects pipeline leak rapidly and precisely. (author)

  8. Leak detection for underground storage tanks

    International Nuclear Information System (INIS)

    Durgin, P.B.; Young, T.M.

    1993-01-01

    This symposium was held in New Orleans, Louisiana on January 29, 1992. The purpose of this conference was to provide a forum for exchange of state-of-the-art information on leak detection for underground storage tanks that leaked fuel. A widespread concern was protection of groundwater supplies from these leaking tanks. In some cases, the papers report on research that was conducted two or three years ago but has never been adequately directed to the underground storage tank leak-detection audience. In other cases, the papers report on the latest leak-detection research. The symposium was divided into four sessions that were entitled: Internal Monitoring; External Monitoring; Regulations and Standards; and Site and Risk Evaluation. Individual papers have been cataloged separately for inclusion in the appropriate data bases

  9. Leak detection/verification

    Energy Technology Data Exchange (ETDEWEB)

    Krhounek, V.; Zdarek, J.; Pecinka, L. [Nuclear Research Institute, Rez (Czech Republic)

    1997-04-01

    Loss of coolant accident (LOCA) experiments performed as part of a Leak Before Break (LBB) analysis are very briefly summarized. The aim of these experiments was to postulate the leak rates of the coolant. Through-wall cracks were introduced into pipes by fatigue cycling and hydraulically loaded in a test device. Measurements included coolant pressure and temperature, quantity of leaked coolant, displacement of a specimen, and acoustic emission. Small cracks were plugged with particles in the coolant during testing. It is believed that plugging will have no effect in cracks with leak rates above 35 liters per minute. The leak rate safety margin of 10 is sufficient for cracks in which the leak rate is more than 5 liters per minute.

  10. Permanent underwater leak detector

    International Nuclear Information System (INIS)

    Costello, L; McStay, D; Moodie, D; Kane, D

    2009-01-01

    A new optoelectronic sensor for the real time monitoring of key components such as valves and connectors within the subsea production equipment for leaks of hydraulic fluid is reported. The sensor is capable of detecting low concentrations of such fluids, allowing the early detection of small leaks, and the ability to monitor the evolution of the leak-rate with time, hence providing an important new tool in complying with environmental requirements, enabling early intervention and optimising subsea production

  11. Ultrasensitive leak detection

    International Nuclear Information System (INIS)

    Winkelman, C.R.; Davidson, H.G.

    1978-01-01

    The objective of this investigation was to develop a method of detecting leaks to a sensitivity of 1.0 x 10 -13 std/cm 3 /s in vacuum devices and to develop a qualifiable standard leak to provide system calibration at this leak rate. The development work demonstrated that minimum detectable leak rates of 6.5 x 10 -14 std/cm 3 /s and 5.5 x 10 -15 std/cm 3 /s are possible for respective analog and digital measurement modes

  12. Thermodynamic analysis of direct internal reforming of methane and butane in proton and oxygen conducting fuel cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Geerlings, J.J.C.

    2008-01-01

    We present results of a thermodynamic analysis of direct internal reforming fuel cells, based on either a proton conducting fuel cell (FC-H+) or an oxygen ion conducting fuel cell (FC-O2-). We analyze the option of methane as fuel as well as butane. The model self-consistently combines all chemical

  13. Leak detection systems for VVER units based on leak before break concept. PowerPoint presentation

    International Nuclear Information System (INIS)

    Matal, Oldrich

    2010-01-01

    To comply with international standards, independent leak monitoring systems should be installed based on the monitoring of different physical parameters capable of detecting any small leak within one hour from the start of the leak. Such leak detection systems are based mainly on acoustic emission monitoring, humidity monitoring and/or radiation monitoring. Advanced systems integrate the monitoring of different physical parameters into one integrated leak detection system. The Integrated Leak Detection System (ILDS) for NPP Metsamor is described. This system consists of three independent leak detection subsystems, viz. LEMOP (LEak MOnitoring of Pipelines) based on acoustic emission monitoring, HUMOS (HUmidity MOnitoring System) based on humidity monitoring, and RAMOS (RAdiation MOnitoring System) based on radiation monitoring). The Integrated Leak Detection System (ILDS) collects data from the three systems, performs data evaluation, data storage, generates alarms and provides a user interface for the whole system including all subsystems. An example of DiagAssist user interface in the ILDS system in the pictorial form. (P.A.)

  14. Polarized proton beam development at COSY with EDDA as a fast internal polarimeter

    International Nuclear Information System (INIS)

    Hinterberger, F.

    2001-01-01

    Polarized protons in the Cooler Synchrotron COSY encounter five imperfection and nine intrinsic depolarizing resonances during the acceleration from 300 to 3300 MeV/c. When crossing imperfection resonances vertical correction dipoles are excited in order to enhance the average vertical displacement and thereby the resonance strength to result in a complete spin flip without loss of polarization. When crossing intrinsic resonances a rapid vertical tune jump is applied to minimize polarization losses. In order to find the optimum machine parameters a novel and fast method was developed to measure the internal beam polarization as a function of the beam momentum in the vicinity of a depolarizing resonance as well as in the full acceleration ramp. Using very thin internal CH 2 - and/or C-fiber targets the polarization is deduced from the left-right asymmetry of fast scaler rates. To this end the EDDA detector is used. This detector consists of two cylindrical scintillation hodoscope layers covering about 87% of 4π for pp elastic scattering. The effective analyzing power of the fast method is obtained by a special calibration procedure using a 'slow but proper' EDDA-style measurement of the elastic pp scattering asymmetries. For this calibration precise analyzing power excitation functions measured by EDDA became available in time

  15. Internal friction measurements of Mo after low-temperature proton irradiation

    International Nuclear Information System (INIS)

    Tanimoto, H.; Mizubayashi, H.; Masuda, R.; Okuda, S.; Tagishi, Y.

    1992-01-01

    Internal friction measurements are performed in Mo after 20 MeV proton irradiation in order to clarify the behavior of self-interstitial atoms (SIA's) in Mo. In the low dose range, strong dislocation pinning suggesting the free migration of defects is observed at about 40 K and weak pinning at about 25 K. The features are very similar to those reported after neutron irradiation except that the 25 K pinning is much smaller after proton irradiation. The result suggests that the migration of free SIA's is responsible for the 40 K pinning and that of SIA-defect clusters, probably di-SIA's, formed during irradiation for the 25 K pinning. In the high dose range, the relaxation peaks are observed at about 13 and 41 K, where the close similarities are found between the present peaks and the corresponding peaks reported after neutron irradiation except that the peak height of the 41 K peak per unit concentration of Frenkel pairs (FP) tends to increase strongly with decreasing dose here. The latter fact suggests the strong interaction between SIA's. Then the smallness of the 41 K peak reported after electron irradiation with very high dose could be explained by an increased interaction between SIA's, but not by the two-dimensional migration of SIA's as proposed by Jacques and Robrock. Deformation given prior to irradiation causes a drastic decrease in the modulus defects associated with FP's (so-called bulk effect) and in the 13 K peak height. After neutron irradiation, no such effect of deformation was reported. A possible origin for this difference is discussed. (orig.)

  16. Cold Leak Tests of LHC Beam Screens

    CERN Document Server

    Collomb-Patton, C; Jenninger, B; Kos, N

    2009-01-01

    In order to guide the high energy proton beams inside its two 27 km long vacuum rings, the Large Hadron Collider (LHC) at CERN, Geneva, makes use of superconducting technology to create the required magnetic fields. More than 4000 beam screens, cooled at 7 20 K, are inserted inside the 1.9 K beam vacuum tubes to intercept beam induced heat loads and to provide dynamic vacuum stability. As extremely high helium leak tightness is required, all beam screens have been leak tested under cold conditions in a dedicated test stand prior to their installation. After describing the beam screen design and its functions, this report focuses on the cold leak test sequence and discusses the results.

  17. Leak detection method

    International Nuclear Information System (INIS)

    1978-01-01

    This invention provides a method for removing nuclear fuel elements from a fabrication building while at the same time testing the fuel elements for leaks without releasing contaminants from the fabrication building or from the fuel elements. The vacuum source used, leak detecting mechanism and fuel element fabrication building are specified to withstand environmental hazards. (UK)

  18. Pressure control of a proton beam-irradiated water target through an internal flow channel-induced thermosyphon.

    Science.gov (United States)

    Hong, Bong Hwan; Jung, In Su

    2017-07-01

    A water target was designed to enhance cooling efficiency using a thermosyphon, which is a system that uses natural convection to induce heat exchange. Two water targets were fabricated: a square target without any flow channel and a target with a flow channel design to induce a thermosyphon mechanism. These two targets had the same internal volume of 8 ml. First, visualization experiments were performed to observe the internal flow by natural convection. Subsequently, an experiment was conducted to compare the cooling performance of both water targets by measuring the temperature and pressure. A 30-MeV proton beam with a beam current of 20 μA was used to irradiate both targets. Consequently, the target with an internal flow channel had a lower mean temperature and a 50% pressure drop compared to the target without a flow channel during proton beam irradiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Leaking electricity in domestic appliances

    International Nuclear Information System (INIS)

    Meier, Alan; Rosen, Karen

    1999-01-01

    Many types of home electronic equipment draw electric power when switched off or not performing their principal functions. Standby power use (or ''leaking electricity'') for most appliances ranges from 1 - 20 watts. Even though standby use of each device is small, the combined standby power use of all appliances in a home can easily exceed 50 watts. Leaking electricity is already responsible for 5 to 10 percent of residential electricity use in the United States and over 10 percent in Japan. An increasing number of white goods also have standby power requirements. There is a growing international effort to limit standby power to around one watt per device. New and existing technologies are available to meet this target at little or no extra cost

  20. Leak Detection of High Pressure Feedwater Heater Using Empirical Models

    International Nuclear Information System (INIS)

    Lee, Song Kyu; Kim, Eun Kee; Heo, Gyun Young; An, Sang Ha

    2009-01-01

    Even small leak from tube side or pass partition within the high pressure feedwater heater (HPFWH) causes a significant deficiency in its performance. Plant operation under the HPFWH leak condition for long time will result in cost increase. Tube side leak within HPFWH can produce the high velocity jet of water and it can cause neighboring tube failures. However, most of plants are being operated without any information for internal leaks of HPFWH, even though it is prone to be damaged under high temperature and high pressure operating conditions. Leaks from tubes and/or pass partition of HPFWH occurred in many nuclear power plants, for example, Mihama PS-2, Takahama PS-2 and Point Beach Nuclear Plant Unit 1. If the internal leaks of HPFWH are monitored, the cost can be reduced by inexpensive repairs relative to loss in performance and moreover plant shutdown as well as further tube damages can be prevented

  1. Density overwrites of internal tumor volumes in intensity modulated proton therapy plans for mobile lung tumors

    Science.gov (United States)

    Botas, Pablo; Grassberger, Clemens; Sharp, Gregory; Paganetti, Harald

    2018-02-01

    The purpose of this study was to investigate internal tumor volume density overwrite strategies to minimize intensity modulated proton therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. Internal gross tumor volume (IGTV) and internal clinical target volume (ICTV) structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the average intensity projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement. The density overwrites were: (a) constant filling with 100 HU (C100) or (b) 50 HU (C50), (c) maximum intensity projection (MIP) across phases, and (d) water equivalent path length (WEPL) consideration from beam’s-eye-view. Plans were created optimizing dose-influence matrices calculated with fast GPU Monte Carlo (MC) simulations in each pCT. Plans were evaluated with MC on the 4DCTs using a model of the beam delivery time structure. Dose accumulation was performed using deformable image registration. Interplay effect was addressed applying 10 times rescanning. Significantly less DVH metrics degradation occurred when using MIP and WEPL approaches. Target coverage (D99≥slant 70 Gy(RBE)) was fulfilled in most cases with MIP and WEPL (D{{99}WEPL}=69.2+/- 4.0 Gy (RBE)), keeping dose heterogeneity low (D5-D{{95}WEPL}=3.9+/- 2.0 Gy(RBE)). The mean lung dose was kept lowest by the WEPL strategy, as well as the maximum dose to organs at risk (OARs). The impact on dose levels in the heart, spinal cord and esophagus were patient specific. Overall, the WEPL strategy gives the best performance and should be preferred when using a 3D static geometry for lung cancer IMPT treatment planning. Newly available fast MC methods make it possible to handle long simulations based on 4D data sets to perform studies with high accuracy and efficiency, even prior to individual treatment planning.

  2. Analysis of small leaks

    International Nuclear Information System (INIS)

    Frisch, W.; Hofmann, K.

    1979-01-01

    Problems associated with 'small leaks' are described and requirements are derived for experimental facilities and computer codes. Based on these requirements, a valuation of the existing experimental facilities and codes is presented. Facilities for integral tests in relatively large scale (ex. LOFT) are suitable for small leak test in principle, however minor changes (instrumentation, secondary side) are necessary for the evaluation of certain phenomena. The 'advanced blowdown codes' are capable of describing most of the phenomena occurring during small leak events, however a substantial amount of code development and verification is still needed. In addition, the use of transient codes in small leak analysis is demonstrated. There are some areas (neutronics feedback, influence of control system) in which the use of transient codes is possible and advantageous. (orig.) 891 HP/orig. 892 BRE [de

  3. Traumatic orbital CSF leak

    Science.gov (United States)

    Borumandi, Farzad

    2013-01-01

    Compared to the cerebrospinalfluid (CSF) leak through the nose and ear, the orbital CSF leak is a rare and underreported condition following head trauma. We present the case of a 49-year-old woman with oedematous eyelid swelling and ecchymosis after a seemingly trivial fall onto the right orbit. Apart from the above, she was clinically unremarkable. The CT scan revealed a minimally displaced fracture of the orbital roof with no emphysema or intracranial bleeding. The fractured orbital roof in combination with the oedematous eyelid swelling raised the suspicion for orbital CSF leak. The MRI of the neurocranium demonstrated a small-sized CSF fistula extending from the anterior cranial fossa to the right orbit. The patient was treated conservatively and the lid swelling resolved completely after 5 days. Although rare, orbital CSF leak needs to be included in the differential diagnosis of periorbital swelling following orbital trauma. PMID:24323381

  4. An experiment to study CP violation in the B system using an internal target at the HERA proton ring

    International Nuclear Information System (INIS)

    Hofmann, W.

    1993-01-01

    Using the HERA proton beam striking an internal wire target, sufficient numbers of B mesons are produced to allow the search for CP violation in B decays with a sensitivity Δsin(2β)∼0.05, provided that the detector can accept and separate multiple interactions per bunch crossing. This report summarizes our present views concerning the layout of the target, of the spectrometer, and of the trigger system, which selects events containing J/ψ candidates. (orig.)

  5. WRSS jumper leak assessment

    International Nuclear Information System (INIS)

    BAILEY, J.W.

    1999-01-01

    The purpose of this assessment is: (1) to assemble and document the facts associated with three recently installed jumpers which have leaked either during actual process operation or during post installation testing; (2) to describe the corrective actions taken and to identify any process improvements which need to be implemented in the Hanford jumper design and installation activities; and (3) to document WRSS jumper leak lessons learned for use by future projects and other jumper design, fabrication, and installation activities

  6. Small liquid sodium leaks

    International Nuclear Information System (INIS)

    Dufresne, J.; Rochedereux, Y.; Antonakas, D.; Casselman, C.; Malet, J.C.

    1986-05-01

    Usually, pessimistic considerations inassessing the safety of secondary sodium loops in LMFBR reactor lead to assume guillotine rupture releasing a large amount of sodium estimate the consequences of large sodium fires. In order to reduce these consequences, one has to detect the smallest leak as soon as possible and to evaluate the future of an initial small leak. Analysis of the relationship between crack size and sodium outflow rate; Analysis of a sodium pipe with a small open crack

  7. Pipeline Leak Detection Techniques

    OpenAIRE

    Chis, Timur

    2009-01-01

    Leak detection systems range from simple, visual line walking and checking ones to complex arrangements of hard-ware and software. No one method is universally applicable and operating requirements dictate which method is the most cost effective. The aim of the paper is to review the basic techniques of leak detection that are currently in use. The advantages and disadvantages of each method are discussed and some indications of applicability are outlined.

  8. Pipeline Leak Detection Techniques

    Directory of Open Access Journals (Sweden)

    Timur Chis, Ph.D., Dipl.Eng.

    2007-01-01

    Full Text Available Leak detection systems range from simple, visual line walking and checking ones to complex arrangements of hard-ware and software. No one method is universally applicable and operating requirements dictate which method is the most cost effective. The aim of the paper is to review the basic techniques of leak detection that are currently in use. The advantages and disadvantages of each method are discussed and some indications of applicability are outlined.

  9. Low Level Leaks

    Science.gov (United States)

    1998-01-01

    NASA has transferred the improved portable leak detector technology to UE Systems, Inc.. This instrument was developed to detect leaks in fluid systems of critical launch and ground support equipment. This system incorporates innovative electronic circuitry, improved transducers, collecting horns, and contact sensors that provide a much higher degree of reliability, sensitivity and versatility over previously used systems. Potential commercial uses are pipelines, underground utilities, air-conditioning systems, petrochemical systems, aerospace, power transmission lines and medical devices.

  10. Apparatus for Leak Testing Pressurized Hoses

    Science.gov (United States)

    Underwood, Steve D. (Inventor); Garrison, Steve G. (Inventor); Gant, Bobby D. (Inventor); Palmer, John R. (Inventor)

    2015-01-01

    A hose-attaching apparatus for leak-testing a pressurized hose may include a hose-attaching member. A bore may extend through the hose-attaching member. An internal annular cavity may extend coaxially around the bore. At least one of a detector probe hole and a detector probe may be connected to the internal annular cavity. At least a portion of the bore may have a diameter which is at least one of substantially equal to and less than a diameter of a hose to be leak-tested.

  11. Evaluation of internal and external doses from $^{11}C$ produced in the air in high energy proton accelerator tunnels

    CERN Document Server

    Endo, A; Kanda, Y; Oishi, T; Kondo, K

    2001-01-01

    Air has been irradiated with high energy protons at the 12 GeV proton synchrotron to obtain the following parameters essential for the internal dose evaluation from airborne /sup 11/C produced through nuclear spallation reactions: the abundance of gaseous and particulate /sup 11/C, chemical forms, and particle size distribution. It was found that more than 98% of /sup 11/C is present as gas and the rest is aerosol. The gaseous components were only /sup 11/CO and /sup 11/CO/sub 2/ and their proportions were approximately 80% and 20%, respectively. The particulate /sup 11/C was found to be sulphate and/or nitrate aerosols having a log-normal size distribution; the measurement using a diffusion battery showed a geometric mean radius of 0.035 mu m and a geometric standard deviation of 1.8 at a beam intensity of 6.8*10/sup 11/ proton.pulse /sup -1/ and an irradiation time of 9.6 min. By taking the chemical composition and particle size into account, effective doses both from internal and from external exposures pe...

  12. Leak testing using helium leak detector

    International Nuclear Information System (INIS)

    Aparicio, G.; Mathot, S.; Munoz, C.; Orlando, O.

    1997-01-01

    Most of the equipment used in the industry and particularly in the nuclear activity need to be, vacuum or pressure tight, for operative and safety requirements. These devices have to satisfy particular regulations in order to be qualified by means of operating licences. One of the most efficient system to ensure leaktightnes is using a helium leak detector with a mass spectrometer. In this paper we show the equipment and the devices employed in fuel rods fabrication for CAREM project, and some typical material defects. Operating system and the sensitivity of this method is also described. (author) [es

  13. Study on the Measurement of Valve Leak Rate Using Acoustic Emission Technology

    International Nuclear Information System (INIS)

    Lee, Sang-Guk; Park, Jong-Hyuck; Yoo, Keun-Bae; Lee, Sun-Ki; Hong, Sung-Yull

    2006-01-01

    This study is to estimate the feasibility of acoustic emission(AE) method for the internal leak from the valves. In this study, 4 inch ball water valve leak tests using three different leak path and various leak rates were performed in order to analyze AE properties when leaks arise in valve seat. As a result of leak test for specimens simulated valve seat, we conformed that leak sound amplitude increased in proportion to the increase of leak rate, and leak rates were plotted versus peak acoustic amplitudes recorded within those two narrow frequency bands on each spectrum plot. The resulting plots of leak rate versus peak AE amplitude were the primary basis for determining the feasibility of quantifying leak acoustically. The large amount of data attained also allowed a favorable investigation of the effects of different leak paths, leak rates, pressure differentials and AE sensors on the AE amplitude spectrum. From the experimental results, it was suggested that the AE method for monitoring of leak was feasible. This paper describes quantitative measurements of fluid valve leak rates by the analysis of AE. Experimental apparatus were fabricated to accept a variety of leaking water valves in order to determine what characteristics of AE signal change with leak rate. The data for each valve were generated by varying the leak rate and recording the time averaged amplitude of AE versus frequency. Leak rates were varied by modifying the valve seating surfaces in ways designed to simulate actual defects observed in service. Most of the data analysis involved plotting the leak rate versus signal amplitude at a specific frequency to determine how well the two variables correlate in terms of accuracy, resolution, and repeatability

  14. Experiments and calculations to leak openings and leak rates on typical piping components and systems

    International Nuclear Information System (INIS)

    Hoefler, A.; Grebner, H.

    1992-01-01

    Calculations of leak opening and leak rate for through cracks in piping components have been performed. The analyses are pre- or mostly post-calculations to experiments performed at the HDR facility under PWR operating conditions. Piping components under consideration are small diameter straight pipes with circumferential cracks, pipe bends with longitudinal or circumferential cracks and pipe branches with weldment cracks. The component are loaded by internal pressure and opening as well as closing bending moment. The finite element method and two-phase flow leak rate programs are used for the calculations. Results of the analyses are presented as J-integral values, crack opening displacements and areas and leak rates as well as comparisons to the experimental results. 6 refs., 16 figs., 2 tabs

  15. Comparison of leak opening and leak rate calculations to HDR experimental results

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1993-01-01

    During the last years a number of calculations of leak opening and leak rate for through cracks in piping components have been performed. Analyses are pre- or mostly post-calculations to experiments performed at the HDR facility under PWR operating conditions. Piping components under consideration were small diameter straight pipes with circumferential cracks, pipe bends with longitudinal or circumferential cracks and pipe branches with weldment cracks. The components were loaded by internal pressure and opening as well as closing bending moment. The finite element method and two-phase flow leak rate programs were used for the calculations. Results of the analyses are presented as J-integral values, crack opening displacements and areas and leak rates as well as comparisons to the experimental results

  16. Fuel rod leak detector

    International Nuclear Information System (INIS)

    Womack, R.E.

    1978-01-01

    A typical embodiment of the invention detects leaking fuel rods by means of a radiation detector that measures the concentration of xenon-133 ( 133 Xe) within each individual rod. A collimated detector that provides signals related to the energy of incident radiation is aligned with one of the ends of a fuel rod. A statistically significant sample of the gamma radiation (γ-rays) that characterize 133 Xe is accumulated through the detector. The data so accumulated indicates the presence of a concentration of 133 Xe appropriate to a sound fuel rod, or a significantly different concentration that reflects a leaking fuel rod

  17. PFR evaporator leak

    International Nuclear Information System (INIS)

    Smedley, J.A.

    1975-01-01

    PFR has three heat removal circuits each one having an evaporator, superheater, reheater; all separate units. The status of the system was that circuit No 3 was steaming with 10 MW thermal nuclear power; No 1 circuit was filled with sodium but with the evaporator awaiting modification to cure gas entrainment problems already reported. The leak was in No 2 circuit and was located in the evaporator unit. The evaporator is rated at 120 M thermal at full power and as such is a large unit. The circuit was filled with both sodium and water for the first time three weeks before the conference so it was recent history being reported and therefore any figures quoted should be taken as indicative only. The history of the steam generator was that it was built at works to a very high standard and underwent all the usual tests of strength, inspection of welds and helium leak testing. The steam generator is of U tube design with a tube plate to which the boiler tubes are welded, with all the welds in one of two gas spaces. The inlet and outlet sides are separated by a baffle and the salient features are illustrated in the attached figure. The unit achieved a leak tightness better than the detection limit in the helium leak test at works. This limit was assessed as being less than an equivalent leak of 10 -6 g/s water under steam generator service conditions. However even though all the steam generator units passed this test at works a further test was carried out when the circuits had been completed. The test was carried out during commissioning after sodium filling and with the units hot. The method was to introduce a mixture of helium/ argon at 500 pounds/square inch into the water side of the steam generators and measure the helium concentration in the sodium side gas spaces of the circuit. The test lasted many days and under these conditions the sensitivity is such that a leak equivalent to somewhere between 10 -7 to 10 -6 g/s equivalent water leak could be detected, i

  18. PFR evaporator leak

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, J A

    1975-07-01

    PFR has three heat removal circuits each one having an evaporator, superheater, reheater; all separate units. The status of the system was that circuit No 3 was steaming with 10 MW thermal nuclear power; No 1 circuit was filled with sodium but with the evaporator awaiting modification to cure gas entrainment problems already reported. The leak was in No 2 circuit and was located in the evaporator unit. The evaporator is rated at 120 M thermal at full power and as such is a large unit. The circuit was filled with both sodium and water for the first time three weeks before the conference so it was recent history being reported and therefore any figures quoted should be taken as indicative only. The history of the steam generator was that it was built at works to a very high standard and underwent all the usual tests of strength, inspection of welds and helium leak testing. The steam generator is of U tube design with a tube plate to which the boiler tubes are welded, with all the welds in one of two gas spaces. The inlet and outlet sides are separated by a baffle and the salient features are illustrated in the attached figure. The unit achieved a leak tightness better than the detection limit in the helium leak test at works. This limit was assessed as being less than an equivalent leak of 10{sup -6} g/s water under steam generator service conditions. However even though all the steam generator units passed this test at works a further test was carried out when the circuits had been completed. The test was carried out during commissioning after sodium filling and with the units hot. The method was to introduce a mixture of helium/ argon at 500 pounds/square inch into the water side of the steam generators and measure the helium concentration in the sodium side gas spaces of the circuit. The test lasted many days and under these conditions the sensitivity is such that a leak equivalent to somewhere between 10{sup -7} to 10{sup -6} g/s equivalent water leak could be

  19. The concept of leak before failure

    International Nuclear Information System (INIS)

    Pellissier-Tanon, A.

    1985-01-01

    The ability to demonstrate the state of leak before failure introduce a new tangible element in the estimation of safety from which it becomes possible to estimate more rationnally the risks associated to crack formation. This paper presents the international positions on the full section break suppression of steam and primary pipes (Federal Republic of Germany, USA, France) [fr

  20. Capillary leak syndrome: etiologies, pathophysiology, and management.

    Science.gov (United States)

    Siddall, Eric; Khatri, Minesh; Radhakrishnan, Jai

    2017-07-01

    In various human diseases, an increase in capillary permeability to proteins leads to the loss of protein-rich fluid from the intravascular to the interstitial space. Although sepsis is the disease most commonly associated with this phenomenon, many other diseases can lead to a "sepsis-like" syndrome with manifestations of diffuse pitting edema, exudative serous cavity effusions, noncardiogenic pulmonary edema, hypotension, and, in some cases, hypovolemic shock with multiple-organ failure. The term capillary leak syndrome has been used to describe this constellation of disease manifestations associated with an increased capillary permeability to proteins. Diseases other than sepsis that can result in capillary leak syndrome include the idiopathic systemic capillary leak syndrome or Clarkson's disease, engraftment syndrome, differentiation syndrome, the ovarian hyperstimulation syndrome, hemophagocytic lymphohistiocytosis, viral hemorrhagic fevers, autoimmune diseases, snakebite envenomation, and ricin poisoning. Drugs including some interleukins, some monoclonal antibodies, and gemcitabine can also cause capillary leak syndrome. Acute kidney injury is commonly seen in all of these diseases. In addition to hypotension, cytokines are likely to be important in the pathophysiology of acute kidney injury in capillary leak syndrome. Fluid management is a critical part of the treatment of capillary leak syndrome; hypovolemia and hypotension can cause organ injury, whereas capillary leakage of administered fluid can worsen organ edema leading to progressive organ injury. The purpose of this article is to discuss the diseases other than sepsis that produce capillary leak and review their collective pathophysiology and treatment. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  1. Acoustic leak detection development in the USA

    International Nuclear Information System (INIS)

    Greene, D.A.; Malovrh, J.W.; Magee, P.M.

    1984-01-01

    Acoustic monitoring systems that detect and locate a leak of water/steam from a defective tube in an LMFBR steam generator have been developed in the United States. A low frequency (approx. 10 KHz) system was developed by General Electric, and a high frequency (200 to 300 KHz) system by Rockwell International with support from Argonne National Laboratory. A comprehensive base technology program provided absolute signal amplitudes, background noise amplitudes, and signal source-to-detector transfer functions. Field tests of these systems demonstrated an ability to detect and locate simulated leaks under operating and quiescent conditions in an LMFBR steam generator. (author)

  2. An experiment to study CP violation in the B system using an internal target at the HERA proton ring

    International Nuclear Information System (INIS)

    Hofmann, W.

    1993-03-01

    A group of physicists centered around the ARGUS collaboration got interested in hadron accelerators as a prolific source of B hadrons. The group is presently studying the option of a major-B-physics experiment to be performed at the HERA proton storage ring in fixed target mode using an internal target. Basic goal of the experiment is the detection of CP violation in the 'gold plated' B 0 → J/Ψ K s decay mode, using a dedicated detector triggered on lepton pairs from J/Ψ decay. (orig./HSI)

  3. Ultrasonic leak detection

    International Nuclear Information System (INIS)

    Murphy, R.V.

    1977-01-01

    A scanning ultrasonic microphone was used to detect the presence and locate the sources of hydraulic noises in piping systems in a reactor environment. The intensity changes of the noises correspond to changes of flow conditions within the system caused by throttled valves, flow rate changes, and leaks. (author)

  4. Study on the Fluid Leak Diagnosis for Steam Valve in Power Plant

    International Nuclear Information System (INIS)

    Lee, Sang-Guk; Park, Jong-Hyuck; Yoo, Keun-Bae; Lee, Sun-Ki; Hong, Sung-Yull

    2006-01-01

    This study aims to estimate the applicability of acoustic emission(AE) method for the internal fluid leak from the valves. In this study, 4 inch gate steam valve leak tests were performed in order to analyze AE properties when leaks arise in valve seat. As a result of leak test for valve seat in a secondary system of power plant, we conformed that leak sound level increased in proportion to the increase of leak rate, and leak rates were compared to simulated tests. The resulting plots of leak rate versus peak frequency and AE signal level were the primary basis for determining the feasibility of quantifying leak acoustically. Previously, the large amount of data attained also allowed a favorable investigation of the effects of different leak paths, leak rates, pressure differentials through simulated test. All results of application tests are compared with results of simulated test. From the application tests, it was suggested that the AE method for diagnosis of steam leak was applicable. This paper presents quantitative measurements of fluid valve leak conditions by the analysis of AE parameter, FFT(fast fourier transform) and RMS(root mean square) level. Test apparatus were fabricated to accept a variety of leaking steam valves in order to determine what characteristics of AE signal change with leak conditions. The data for each valve were generated by varying the leak rate and recording the averaged RMS level versus time and frequency versus amplitude(FFT). Leak rates were varied by the valve differential pressure and valve size and leaking valves were observed in service. Most of the data analysis involved plotting the leak rate versus RMS level at a specific frequency to determine how well the two variables correlate in terms of accuracy, resolution, and repeatability

  5. Operational Philosophy Concerning Manned Spacecraft Cabin Leaks

    Science.gov (United States)

    DeSimpelaere, Edward

    2011-01-01

    The last thirty years have seen the Space Shuttle as the prime United States spacecraft for manned spaceflight missions. Many lessons have been learned about spacecraft design and operation throughout these years. Over the next few decades, a large increase of manned spaceflight in the commercial sector is expected. This will result in the exposure of commercial crews and passengers to many of the same risks crews of the Space Shuttle have encountered. One of the more dire situations that can be encountered is the loss of pressure in the habitable volume of the spacecraft during on orbit operations. This is referred to as a cabin leak. This paper seeks to establish a general cabin leak response philosophy with the intent of educating future spacecraft designers and operators. After establishing a relative definition for a cabin leak, the paper covers general descriptions of detection equipment, detection methods, and general operational methods for management of a cabin leak. Subsequently, all these items are addressed from the perspective of the Space Shuttle Program, as this will be of the most value to future spacecraft due to similar operating profiles. Emphasis here is placed upon why and how these methods and philosophies have evolved to meet the Space Shuttle s needs. This includes the core ideas of: considerations of maintaining higher cabin pressures vs. lower cabin pressures, the pros and cons of a system designed to feed the leak with gas from pressurized tanks vs. using pressure suits to protect against lower cabin pressures, timeline and consumables constraints, re-entry considerations with leaks of unknown origin, and the impact the International Space Station (ISS) has had to the standard Space Shuttle cabin leak response philosophy. This last item in itself includes: procedural management differences, hardware considerations, additional capabilities due to the presence of the ISS and its resource, and ISS docking/undocking considerations with a

  6. Leaking Fuel Impacts and Practices

    International Nuclear Information System (INIS)

    Hozer, Zoltan; Szabo, Peter; Somfai, Barbara; Cherubini, Marco; Aldworth, Robin; Waeckel, Nicolas; Delorme, Tim; Dickson, Raymond; Fujii, Hajime; Rey Gayo, Jose Maria; Grant, Wade; Gorzel, Andreas; Hellwig, Christian; Kamimura, Katsuichiro; Sugiyama, Tomoyuki; Klouzal, Jan; Miklos, Marek; Nagase, Fumihisa; Nilsson, Marcus; Petit, Marc; Richards, Stuart; Lundqvist Saleh, Tobias; Stepniewski, Marek; Sim, Ki Seob; ); Rehacek, Radomir; Kissane, Martin; )

    2014-01-01

    The impact of leaking fuel rods on the operation of nuclear power plants and the practices of handling leaking fuel has been reviewed by the CSNI Working Group on Fuel Safety in order to promote a better understanding on the handling of leaking fuel in power reactors, as well as to discuss and review the current practices in member countries to help in decisions on the specification of reactor operation conditions with leaking fuel rods and on the handling of leaking fuel after removal from reactor. Experts from 15 countries provided data on the handling of leaking fuel in PWR, BWR, VVER and PHWR reactor types. The review covered the operation of NPP reactors with leaking fuel, wet and dry storage and transport of leaking assemblies. The methods and applied instruments to identify leaking fuel assemblies and the repair of them were addressed in the review. Special attention was paid to the activity release from leaking rods in the reactor and under storage conditions. The consideration of leaking fuel in safety analyses on core behaviour during postulated accidents was also discussed in the review. The main conclusions of the review pointed out that the activity release from leaking fuel rods in the reactor can be handled by technological systems, or in case of failure of too many rods the reactor can be shutdown to minimize activity release. Under accident conditions and operational transients the leaking rods may produce coolant activity concentration peaks. The storage of spent leaking fuel is normally characterised by moderate release of radionuclides from the fuel. The power plants apply limits for activity concentration to limit the amount of leaking rods in the core. In different countries, the accident analyses take into consideration the potential release from leaking fuel rods in design basis accidents in different ways. Some power plants apply special tools for handling and repair of leaking assemblies and rods. The leaking rods are stored together with

  7. Hazardous fluid leak detector

    Science.gov (United States)

    Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.

    1996-01-01

    A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.

  8. Natural gas leak mapper

    Science.gov (United States)

    Reichardt, Thomas A [Livermore, CA; Luong, Amy Khai [Dublin, CA; Kulp, Thomas J [Livermore, CA; Devdas, Sanjay [Albany, CA

    2008-05-20

    A system is described that is suitable for use in determining the location of leaks of gases having a background concentration. The system is a point-wise backscatter absorption gas measurement system that measures absorption and distance to each point of an image. The absorption measurement provides an indication of the total amount of a gas of interest, and the distance provides an estimate of the background concentration of gas. The distance is measured from the time-of-flight of laser pulse that is generated along with the absorption measurement light. The measurements are formated into an image of the presence of gas in excess of the background. Alternatively, an image of the scene is superimosed on the image of the gas to aid in locating leaks. By further modeling excess gas as a plume having a known concentration profile, the present system provides an estimate of the maximum concentration of the gas of interest.

  9. Does a dyon leak

    International Nuclear Information System (INIS)

    Grossman, B.

    1983-01-01

    In the presence of a CP-nonconservation measured by an angle theta, the ground state of a point magnetic monopole is shown to have an electric charge of value -etheta/2π which changes discontinuously to zero for massless fermions. A new version of Levinson's theorem is also given. The latter effect as well as the S-wave helicity flip of a dyon can be interpreted as a leak at the origin

  10. Aspects of leak detection

    International Nuclear Information System (INIS)

    Chivers, T.C.

    1997-01-01

    A requirement of a Leak before Break safety case is that the leakage from the through wall crack be detected prior to any growth leading to unacceptable failure. This paper sets out to review some recent developments in this field. It does not set out to be a comprehensive guide to all of the methods available. The discussion concentrates on acoustic emission and how the techniques can be qualified and deployed on operational plant

  11. Aspects of leak detection

    Energy Technology Data Exchange (ETDEWEB)

    Chivers, T.C. [Berkeley Technology Centre, Glos (United Kingdom)

    1997-04-01

    A requirement of a Leak before Break safety case is that the leakage from the through wall crack be detected prior to any growth leading to unacceptable failure. This paper sets out to review some recent developments in this field. It does not set out to be a comprehensive guide to all of the methods available. The discussion concentrates on acoustic emission and how the techniques can be qualified and deployed on operational plant.

  12. CSNI specialist meeting on leak-before-break in nuclear reactor piping: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1984-08-01

    On September 1 and 2, 1983, the CSNI subcommittee on primary system integrity held a special meeting in Monterey, California, on the subject of leak-before-break in nuclear reactor piping systems. The purpose of the meeting was to provide an international forum for the exchange of ideas, positions, and research results; to identify areas requiring additional research and development; and to determine the general attitude toward acceptance of the leak-before-break concept. The importance of the leak-before-break issue was evidenced by excellent attendance at the meeting and through active participation by the meeting attendees. Approximately 125 people representing fifteen different nations attended the meeting. The meeting was divided into four technical sessions addressing the following areas: Application of Piping Fracture Mechanics to Leak-Before Break, Leak Rate and Leak Detection, Leak-Before-Break Studies, Methods and Results, Current and Proposed Positions on Leak-Before-Break.

  13. CSNI specialist meeting on leak-before-break in nuclear reactor piping: proceedings

    International Nuclear Information System (INIS)

    1984-08-01

    On September 1 and 2, 1983, the CSNI subcommittee on primary system integrity held a special meeting in Monterey, California, on the subject of leak-before-break in nuclear reactor piping systems. The purpose of the meeting was to provide an international forum for the exchange of ideas, positions, and research results; to identify areas requiring additional research and development; and to determine the general attitude toward acceptance of the leak-before-break concept. The importance of the leak-before-break issue was evidenced by excellent attendance at the meeting and through active participation by the meeting attendees. Approximately 125 people representing fifteen different nations attended the meeting. The meeting was divided into four technical sessions addressing the following areas: Application of Piping Fracture Mechanics to Leak-Before Break, Leak Rate and Leak Detection, Leak-Before-Break Studies, Methods and Results, Current and Proposed Positions on Leak-Before-Break

  14. Novel Methods of Hydrogen Leak Detection

    International Nuclear Information System (INIS)

    Pushpinder S Puri

    2006-01-01

    For hydrogen to become a consumer fuel for automotive and domestic power generation, safety is paramount. Today's hydrogen systems are built with inherent safety measures and multiple levels of protection. However, human senses, in particular, the sense of smell, is considered the ultimate safeguards against leaks. Since hydrogen is an odorless gas, use of odorants to detect leaks, as is done in case of natural gas, is obvious solution. The odorants required for hydrogen used in fuel cells have a unique requirement which must be met. This is because almost all of the commercial odorants used in gas leak detection contain sulfur which acts as poison for the catalysts used in hydrogen based fuel cells, most specifically for the PEM (polymer electrolyte membrane or proton exchange membrane) fuel cells. A possible solution to this problem is to use non-sulfur containing odorants. Chemical compounds based on mixtures of acrylic acid and nitrogen compounds have been adopted to achieve a sulfur-free odorization of a gas. It is, therefore, desired to have a method and system for hydrogen leak detection using odorant which can incorporate a uniform concentration of odorant in the hydrogen gas, when odorants are mixed in the hydrogen storage or delivery means. It is also desired to develop methods where the odorant is not added to the bulk hydrogen, keeping it free of the odorization additives. A series of novel solutions are proposed which address the issues raised above. These solutions are divided into three categories as follows: 1. Methods incorporating an odorant in the path of hydrogen leak as opposed to adding it to the hydrogen gas. 2. Methods where odorants are generated in-situ by chemical reaction with the leaking hydrogen 3. Methods of dispensing and storing odorants in high pressure hydrogen gas which release odorants to the gas at a uniform and predetermined rates. Use of one or more of the methods described here in conjunction with appropriate engineering

  15. In-situ Monitoring of Internal Local Temperature and Voltage of Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2010-06-01

    Full Text Available The distribution of temperature and voltage of a fuel cell are key factors that influence performance. Conventional sensors are normally large, and are also useful only for making external measurements of fuel cells. Centimeter-scale sensors for making invasive measurements are frequently unable to accurately measure the interior changes of a fuel cell. This work focuses mainly on fabricating flexible multi-functional microsensors (for temperature and voltage to measure variations in the local temperature and voltage of proton exchange membrane fuel cells (PEMFC that are based on micro-electro-mechanical systems (MEMS. The power density at 0.5 V without a sensor is 450 mW/cm2, and that with a sensor is 426 mW/cm2. Since the reaction area of a fuel cell with a sensor is approximately 12% smaller than that without a sensor, but the performance of the former is only 5% worse.

  16. In-situ monitoring of internal local temperature and voltage of proton exchange membrane fuel cells.

    Science.gov (United States)

    Lee, Chi-Yuan; Fan, Wei-Yuan; Hsieh, Wei-Jung

    2010-01-01

    The distribution of temperature and voltage of a fuel cell are key factors that influence performance. Conventional sensors are normally large, and are also useful only for making external measurements of fuel cells. Centimeter-scale sensors for making invasive measurements are frequently unable to accurately measure the interior changes of a fuel cell. This work focuses mainly on fabricating flexible multi-functional microsensors (for temperature and voltage) to measure variations in the local temperature and voltage of proton exchange membrane fuel cells (PEMFC) that are based on micro-electro-mechanical systems (MEMS). The power density at 0.5 V without a sensor is 450 mW/cm(2), and that with a sensor is 426 mW/cm(2). Since the reaction area of a fuel cell with a sensor is approximately 12% smaller than that without a sensor, but the performance of the former is only 5% worse.

  17. Mobile leak testing system

    International Nuclear Information System (INIS)

    Ungr, F.

    The design and implementation are described of a mobile testing unit ULTRATEST M for helium leak tests. The equipment has been developed by Leybold-Heraeus GmbH in Cologne and is in-built in a Mercedes-Benz 208 van. The equipment is designed for the operative use in assembly and construction of nuclear power plants and its throughput is sufficient for checking the whole upper reactor block. It may also be used for removing defects of vacuum equipment requiring a high level of tightness or equally demanding equipment used in the chemical industry. Experience with the equipment is described. (B.S.)

  18. Deconstructing Gender Stereotypes in Leak

    Directory of Open Access Journals (Sweden)

    Nengah Bawa Atmadja

    2015-05-01

    Full Text Available The belief of Balinese people towards leak still survive. Leak is a magic based on durgaism that can transform a person from human to another form, such as apes, pigs, etc. People tend to regard leak as evil. In general, the evilness is constructed in gender stereotypes, so it is identified that leak are always women. This idea is a power game based on the ideology of patriarchy that provides legitimacy for men to dominate women with a plea for social harmony. As a result, women are marginalized in the Balinese society. Women should be aware of so it would provide encouragement for them to make emancipatory changes dialogically. Kepercayaan orang Bali terhadap leak tetap bertahan sampai saat ini. Leak adalah sihir yang berbasiskan durgaisme yang dapat mengakibatkan seseorang bisa merubah bentuk dari manusia ke wujud yang lain, misalnya kera, babi, dll. Leak termasuk magi hitam sehingga dinilai bersifat jelek. Pada umumnya perempuan diidentikkan dengan leak sehingga melahirkan asumsi yang bermuatan steriotip gender bahwa leak = perempuan. Gagasan ini merupakan permainan kekuasaan berbasis ideologi patriarkhi dan sekaligus memberikan legitimasi bagi laki-laki untuk menguasai perempuan dengan dalih demi keharmonisan sosial. Akibatnya, perempuan menjadi termarginalisasi pada masyarakat Bali.  Perempuan harus menyadarinya sehingga memberikan dorongan bagi mereka untuk melakukan perubahan secara dialogis emansipatoris.

  19. Radiation leaking protection device

    International Nuclear Information System (INIS)

    Sunami, Yoshio; Mitsumori, Kojiro

    1980-01-01

    Purpose: To prevent radioactivity from leaking outside of a reactor container by way of pipeways passing therethrough, by supplying pressurized fluid between each of a plurality of valves for separating the pipeways. Constitution: Pressurized fluid is supplied between each of a plurality of valves for separating pipeways. For instance, water in a purified water tank is pressurized by a pressure pump and the pressure of the pressurized water is controlled by a differential pressure detector, a pressure controller and a pressure control valve. In the case if a main steam pipe is ruptured outside of the reactor container or to be repaired, the separation valves are wholly closed and then the pressurizing device is actuated to supply pressurized water containing no radioactivity from the purified water tank to the position between the valves. The pressure in the pressurized water is controlled such that it is always higher by a predetermined level than the pressure in the reactor. This prevents the radioacitivity in the reactor core from leaking outside of the container passing through the valves, whereby radiation exposure in the working can be reduced and the circumferential contamination upon accident of pipeway rupture can be decreased. (Kawakami, Y.)

  20. 40 CFR 63.1005 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Leak repair. 63.1005 Section 63.1005... Standards for Equipment Leaks-Control Level 1 § 63.1005 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected no later than 15 calendar days after it is detected, except as...

  1. 40 CFR 63.1024 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Leak repair. 63.1024 Section 63.1024... Standards for Equipment Leaks-Control Level 2 Standards § 63.1024 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected as soon as practical, but not later than 15 calendar...

  2. 40 CFR 65.105 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Leak repair. 65.105 Section 65.105... FEDERAL AIR RULE Equipment Leaks § 65.105 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected as soon as practical but not later than 15 calendar days after it is...

  3. Chemochromic Hydrogen Leak Detectors

    Science.gov (United States)

    Roberson, Luke; Captain, Janine; Williams, Martha; Smith, Trent; Tate, LaNetra; Raissi, Ali; Mohajeri, Nahid; Muradov, Nazim; Bokerman, Gary

    2009-01-01

    At NASA, hydrogen safety is a key concern for space shuttle processing. Leaks of any level must be quickly recognized and addressed due to hydrogen s lower explosion limit. Chemo - chromic devices have been developed to detect hydrogen gas in several embodiments. Because hydrogen is odorless and colorless and poses an explosion hazard, there is an emerging need for sensors to quickly and accurately detect low levels of leaking hydrogen in fuel cells and other advanced energy- generating systems in which hydrogen is used as fuel. The device incorporates a chemo - chromic pigment into a base polymer. The article can reversibly or irreversibly change color upon exposure to hydrogen. The irreversible pigment changes color from a light beige to a dark gray. The sensitivity of the pigment can be tailored to its application by altering its exposure to gas through the incorporation of one or more additives or polymer matrix. Furthermore, through the incorporation of insulating additives, the chemochromic sensor can operate at cryogenic temperatures as low as 78 K. A chemochromic detector of this type can be manufactured into any feasible polymer part including injection molded plastic parts, fiber-spun textiles, or extruded tapes. The detectors are simple, inexpensive, portable, and do not require an external power source. The chemochromic detectors were installed and removed easily at the KSC launch pad without need for special expertise. These detectors may require an external monitor such as the human eye, camera, or electronic detector; however, they could be left in place, unmonitored, and examined later for color change to determine whether there had been exposure to hydrogen. In one type of envisioned application, chemochromic detectors would be fabricated as outer layers (e.g., casings or coatings) on high-pressure hydrogen storage tanks and other components of hydrogen-handling systems to provide visible indications of hydrogen leaks caused by fatigue failures or

  4. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    Fearing, H.W.

    1990-01-01

    We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs

  5. Intelligence Leaks: What Is the Role of the Leak and the Leaker in U.S. Democracy?

    Science.gov (United States)

    2014-03-01

    WikiLeaks, the government did not fight a battle against the media due, in part, to the jurisprudence established by the Pentagon Papers . (The U.S...Accountability.” University of Georgia, School of Public and International Affairs, Occasional Paper . Johnson, Lyndon B. “Special Message to the Congress on...between the Pentagon Papers and WikiLeaks to Edward Snowden. 14. SUBJECT TERMS Bradley Manning, Daniel Ellsberg, executive

  6. Device provides controlled gas leaks

    Science.gov (United States)

    Kami, S. K.; King, H. J.

    1968-01-01

    Modified palladium leak device provides a controlled release /leak/ of very small quantities of gas at low or medium pressures. It has no moving parts, requires less than 5 watts to operate, and is capable of releasing the gas either continuously or in pulses at adjustable flow rates.

  7. Tank car leaks gasoline

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    On January 27, 1994, a Canadian National (CN) tank car loaded with gasoline began to leak from a crack in the tank shell on the end of the car near the stub sill. The tank car had been damaged from impact switching. A part of the tank car was sent for laboratory analysis which concluded that: (1) the fracture originated in two locations in welds, (2) the cracks propagated in a symmetrical manner and progressed into the tank plate, (3) the fracture surface revealed inadequate weld fusion. A stress analysis of the tank car was conducted to determine the coupling force necessary to cause the crack. It was noted that over the last decade several problems have occurred pertaining to stub sill areas of tank cars that have resulted in hazardous material spills. An advisory was sent to Transport Canada outlining many examples where tank cars containing serious defects had passed CN inspections that were specifically designed to identify such defects. 4 figs

  8. The Leaking Pipeline

    DEFF Research Database (Denmark)

    Henningsen, Inge; Højgaard, Lis

    2002-01-01

    negotiations of cultural prescriptions of gendered subjectivity and identities, organizational understandings and procedures embedded in specific university cultures, traditional of different science disciplines, and the systemic logic and political rationale of the education and research system....... these positions, and one that maintains that a closer look at the statistics does not support this optimism because women’s percentage in recruitment positions is not increasing as the pool of potential female researchers increases, or to put it metaphorically, “the pipeline is leaking women all along” (Alper...... it identifies and describes a Danish verion of ‘the leaky pipeline’ from analyses of the ratios of women in science from high school through tenured positions. Finally it illustrates the cultural mechanisms at play in this process, based on the results of three studies. The first two analyze the educational...

  9. Hermetic Seal Leak Detection Apparatus

    Science.gov (United States)

    Kelley, Anthony R. (Inventor)

    2013-01-01

    The present invention is a hermetic seal leak detection apparatus, which can be used to test for hermetic seal leaks in instruments and containers. A vacuum tight chamber is created around the unit being tested to minimize gas space outside of the hermetic seal. A vacuum inducing device is then used to increase the gas chamber volume inside the device, so that a slight vacuum is pulled on the unit being tested. The pressure in the unit being tested will stabilize. If the stabilized pressure reads close to a known good seal calibration, there is not a leak in the seal. If the stabilized pressure reads closer to a known bad seal calibration value, there is a leak in the seal. The speed of the plunger can be varied and by evaluating the resulting pressure change rates and final values, the leak rate/size can be accurately calculated.

  10. ISS Ammonia Leak Detection Through X-Ray Fluorescence

    Science.gov (United States)

    Camp, Jordan; Barthelmy, Scott; Skinner, Gerry

    2013-01-01

    Ammonia leaks are a significant concern for the International Space Station (ISS). The ISS has external transport lines that direct liquid ammonia to radiator panels where the ammonia is cooled and then brought back to thermal control units. These transport lines and radiator panels are subject to stress from micrometeorites and temperature variations, and have developed small leaks. The ISS can accommodate these leaks at their present rate, but if the rate increased by a factor of ten, it could potentially deplete the ammonia supply and impact the proper functioning of the ISS thermal control system, causing a serious safety risk. A proposed ISS astrophysics instrument, the Lobster X-Ray Monitor, can be used to detect and localize ISS ammonia leaks. Based on the optical design of the eye of its namesake crustacean, the Lobster detector gives simultaneously large field of view and good position resolution. The leak detection principle is that the nitrogen in the leaking ammonia will be ionized by X-rays from the Sun, and then emit its own characteristic Xray signal. The Lobster instrument, nominally facing zenith for its astrophysics observations, can be periodically pointed towards the ISS radiator panels and some sections of the transport lines to detect and localize the characteristic X-rays from the ammonia leaks. Another possibility is to use the ISS robot arm to grab the Lobster instrument and scan it across the transport lines and radiator panels. In this case the leak detection can be made more sensitive by including a focused 100-microampere electron beam to stimulate X-ray emission from the leaking nitrogen. Laboratory studies have shown that either approach can be used to locate ammonia leaks at the level of 0.1 kg/day, a threshold rate of concern for the ISS. The Lobster instrument uses two main components: (1) a microchannel plate optic (also known as a Lobster optic) that focuses the X-rays and directs them to the focal plane, and (2) a CCD (charge

  11. Photon and proton activation analysis of iron and steel standards using the internal standard method coupled with the standard addition method

    International Nuclear Information System (INIS)

    Masumoto, K.; Hara, M.; Hasegawa, D.; Iino, E.; Yagi, M.

    1997-01-01

    The internal standard method coupled with the standard addition method has been applied to photon activation analysis and proton activation analysis of minor elements and trace impurities in various types of iron and steel samples issued by the Iron and Steel Institute of Japan (ISIJ). Samples and standard addition samples were once dissolved to mix homogeneously, an internal standard and elements to be determined and solidified as a silica-gel to make a similar matrix composition and geometry. Cerium and yttrium were used as an internal standard in photon and proton activation, respectively. In photon activation, 20 MeV electron beam was used for bremsstrahlung irradiation to reduce matrix activity and nuclear interference reactions, and the results were compared with those of 30 MeV irradiation. In proton activation, iron was removed by the MIBK extraction method after dissolving samples to reduce the radioactivity of 56 Co from iron via 56 Fe(p, n) 56 Co reaction. The results of proton and photon activation analysis were in good agreement with the standard values of ISIJ. (author)

  12. Construction, internal validation and implementation in a mobile application of a scoring system to predict nonadherence to proton pump inhibitors

    Directory of Open Access Journals (Sweden)

    Emma Mares-García

    2017-06-01

    Full Text Available Background Other studies have assessed nonadherence to proton pump inhibitors (PPIs, but none has developed a screening test for its detection. Objectives To construct and internally validate a predictive model for nonadherence to PPIs. Methods This prospective observational study with a one-month follow-up was carried out in 2013 in Spain, and included 302 patients with a prescription for PPIs. The primary variable was nonadherence to PPIs (pill count. Secondary variables were gender, age, antidepressants, type of PPI, non-guideline-recommended prescription (NGRP of PPIs, and total number of drugs. With the secondary variables, a binary logistic regression model to predict nonadherence was constructed and adapted to a points system. The ROC curve, with its area (AUC, was calculated and the optimal cut-off point was established. The points system was internally validated through 1,000 bootstrap samples and implemented in a mobile application (Android. Results The points system had three prognostic variables: total number of drugs, NGRP of PPIs, and antidepressants. The AUC was 0.87 (95% CI [0.83–0.91], p < 0.001. The test yielded a sensitivity of 0.80 (95% CI [0.70–0.87] and a specificity of 0.82 (95% CI [0.76–0.87]. The three parameters were very similar in the bootstrap validation. Conclusions A points system to predict nonadherence to PPIs has been constructed, internally validated and implemented in a mobile application. Provided similar results are obtained in external validation studies, we will have a screening tool to detect nonadherence to PPIs.

  13. Experiments on leak-selfwastage and leak-propagation

    International Nuclear Information System (INIS)

    Voss, J.; Vagt, P.; Westenbrugge, J.K. van; Joziasse, J.

    1984-01-01

    During the last years a considerable number of selfwastage experiments with small leaks of different shape and size and for different ferritic materials (2 1/4% Cr - and 12% Cr-steel) were performed by TNO and by INTERATOM, using several sodium test facilities. Many fabrication-methods of artificial micro-leaks were applied and examined. Selfplugging-, selfwastage- and reopening-effects were observed and evaluated during different time periods and under various test conditions. The main results will be discussed. Concerning the leak propagation program of INTERATOM, the first series of experiments was carried out this year. A short status report and some first results will be given. (author)

  14. Energetic magnetospheric protons in the plasma depletion layer

    International Nuclear Information System (INIS)

    Fuselier, S.A.

    1992-01-01

    Interplanetary magnetic field draping against the Earth's dayside subsolar magnetopause creates a region of reduced plasma density and increased magnetic field called the plasma depletion layer. In this region, leakage of energetic ions from the Earth's magnetosphere onto magnetic field lines in the plasma depletion layer can be studied without interference from ions accelerated at the Earth's quasi-parallel bow shock. Active Magnetospheric Particle Tracer Experiment/Charge Composition Explorer (AMPTE/CCE) observations for 13 plasma depletion layer events are used to determine the characteristics of energetic protons between a few keV/e and ∼100keV/e leaked from the magnetosphere. Results indicate that the leaked proton distributions resemble those in the magnetosphere except that they have lower densities and temperatures and much higher velocities parallel (or antiparallel) and perpendicular to the magnetic field. Compared to the low-energy magnetosheath proton distributions present in the depletion layer, the leaked energetic proton distributions typically have substantially higher flow velocities along the magnetic field indicate that the leaked energetic proton distributions to contribute to the energetic proton population seen upstream and downstream from the quasi-parallel bow shock. However, their contribution is small compared to the contribution from acceleration of protons at the bow shock because the leaked proton densities are on the order of 10 times smaller than the energetic proton densities typically observed in the vicinity of the quasi-parallel bow shock

  15. Aerospace Payloads Leak Test Methodology

    Science.gov (United States)

    Lvovsky, Oleg; Grayson, Cynthia M.

    2010-01-01

    Pressurized and sealed aerospace payloads can leak on orbit. When dealing with toxic or hazardous materials, requirements for fluid and gas leakage rates have to be properly established, and most importantly, reliably verified using the best Nondestructive Test (NDT) method available. Such verification can be implemented through application of various leak test methods that will be the subject of this paper, with a purpose to show what approach to payload leakage rate requirement verification is taken by the National Aeronautics and Space Administration (NASA). The scope of this paper will be mostly a detailed description of 14 leak test methods recommended.

  16. Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell.

    Science.gov (United States)

    Lee, Chi-Yuan; Chen, Chia-Hung; Tsai, Chao-Hsuan; Wang, Yu-Syuan

    2018-01-13

    To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC), the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO), so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (PEMFC; (5) customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.

  17. Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2018-01-01

    Full Text Available To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC, the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO, so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS technology to develop a wireless and thin (<50 μm flexible integrated (temperature, flow and CO microsensor. The technical advantages are (1 compactness and three wireless measurement functions; (2 elastic measurement position and accurate embedding; (3 high accuracy and sensitivity and quick response; (4 real-time wireless monitoring of dynamic performance of PEMFC; (5 customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.

  18. Internal proton transfer and H2 rotations in the H5(+) cluster: a marked influence on its thermal equilibrium state.

    Science.gov (United States)

    de Tudela, Ricardo Pérez; Barragán, Patricia; Prosmiti, Rita; Villarreal, Pablo; Delgado-Barrio, Gerardo

    2011-03-31

    Classical and path integral Monte Carlo (CMC, PIMC) "on the fly" calculations are carried out to investigate anharmonic quantum effects on the thermal equilibrium structure of the H5(+) cluster. The idea to follow in our computations is based on using a combination of the above-mentioned nuclear classical and quantum statistical methods, and first-principles density functional (DFT) electronic structure calculations. The interaction energies are computed within the DFT framework using the B3(H) hybrid functional, specially designed for hydrogen-only systems. The global minimum of the potential is predicted to be a nonplanar configuration of C(2v) symmetry, while the next three low-lying stationary points on the surface correspond to extremely low-energy barriers for the internal proton transfer and to the rotation of the H2 molecules, around the C2 axis of H5(+), connecting the symmetric C(2v) minima in the planar and nonplanar orientations. On the basis of full-dimensional converged PIMC calculations, results on the quantum vibrational zero-point energy (ZPE) and state of H5(+) are reported at a low temperature of 10 K, and the influence of the above-mentioned topological features of the surface on its probability distributions is clearly demonstrated.

  19. Tube leak detector

    International Nuclear Information System (INIS)

    Morita, Bunji; Takamura, Koichi; Matsuda, Shigehiro; Kiyosawa, Shun-ichi; Asami, Toru; Yamada, Hiroshi; Naruse, Shin-ichi.

    1995-01-01

    The device of the present invention detects occurrence of leakage in a steam generator, a steam heating tube, or a heat exchanger of a nuclear power plant. Namely, an vibration sensor is disposed at the rear end of a rod-like supersonic resonance member. A node portion for the vibrations of the resonance member is held by a holding member and attached to a wall surface of a can such as a boiler. With such a constitution, the resonance member is resonated by supersonic waves generated upon leakage of the tube. The vibrations are measured by the vibration sensor at the rear end. Presence of leakage is detected by utilizing one or more of resonance frequencies. Since the device adopts a resonance phenomenon, a conduction efficiency of the vibrations is high, thereby enabling to detect leakage at high sensitivity. In addition, the supersonic wave resonance member has its top end directly protruded into a pressure vessel such as a boiler by using a metal or a ceramic which is excellent in heat and pressure resistance. Accordingly, the sound of leak can be detected efficiently. (I.S.)

  20. Analysis of SX farm leak histories - Historical leak model (HLM)

    International Nuclear Information System (INIS)

    Fredenburg, E.A.

    1998-01-01

    This report uses readily available historical information to better define the volume, chemical composition, and Cs-137/Sr-90 amounts for leaks that have occurred in the past for tanks SX-108, SX-109, SX-111, and SX-112. In particular a Historical Leak Model (HLM) is developed that is a month by month reconciliation of tank levels, fill records, and calculated boil-off rates for these tanks. The HLM analysis is an independent leak estimate that reconstructs the tank thermal histories thereby deriving each tank's evaporative volume loss and by difference, its unaccounted losses as well. The HLM analysis was meant to demonstrate the viability of its approach, not necessarily to establish the HLM leak estimates as being definitive. Past leak estimates for these tanks have invariably resorted to soil wetting arguments but the extent of soil contaminated by each leak has always been highly uncertain. There is also a great deal of uncertainty with the HLM that was not quantified in this report, but will be addressed later. These four tanks (among others) were used from 1956 to 1975 for storage of high-level waste from the Redox process at Hanford. During their operation, tank waste temperatures were often as high as 150 C (300 F), but were more typically around 130 C. The primary tank cooling was by evaporation of tank waste and therefore periodic replacement of lost volume with water was necessary to maintain each tank's inventory. This active reflux of waste resulted in very substantial turnovers in tank inventory as well as significant structural degradation of these tanks. As a result of the loss of structural integrity, each of these tanks leaked during their active periods of operation. Unfortunately, the large turnover in tank volume associated with their reflux cooling has made a determination of leak volumes very difficult. During much of these tanks operational histories, inventory losses because of evaporative cooling could have effectively masked any volume

  1. Concentration device for leak liquids

    International Nuclear Information System (INIS)

    Matsumoto, Kaname; Matsuda, Ken; Takabori, Ken-ichi.

    1987-01-01

    Purpose: To improve radioactivity recovery and volume-reducing rates, as well as enable safety and easy handling for leak liquids resulted from reptures in coolant circuits. Constitution: The device of the invention comprises an evaporation vessel filled with leak fluids to a predetermined level, an airtight vessel disposed in the evaporation vessel containing hydrophilic porous material partially immersed in the leak fluids and means for heating the hydrophilic material. In this device, leak liquids are absorbed in the hydrophilic porous material, a great amount of water is evaporated from the outer surface of the hydrophilic porous material exposed above the liquid surface, and salts and radioactive material are remained on the inside and the outer surface of the porous material. The evaporated water content is condensated and recovered in a cooler and the remaining salts, etc. are discarded together with the porous material. The volume-reducing property can be improved by constituting the porous material with burnable material. (Takahashi, M.)

  2. Basis UST leak detection systems

    International Nuclear Information System (INIS)

    Silveria, V.

    1992-01-01

    This paper reports that gasoline and other petroleum products are leaking from underground storage tanks (USTs) at an alarming rate, seeping into soil and groundwater. Buried pipes are an even greater culprit, accounting for most suspected and detected leaks according to Environmental Protection Agency (EPA) estimates. In response to this problem, the EPA issued regulations setting standards for preventing, detecting, reporting, and cleaning up leaks, as well as fiscal responsibility. However, federal regulations are only a minimum; some states have cracked down even harder Plant managers and engineers have a big job ahead of them. The EPA estimates that there are more than 75,000 fuel USTs at US industrial facilities. When considering leak detection systems, the person responsible for making the decision has five primary choices: inventory reconciliation combined with regular precision tightness tests; automatic tank gauging; groundwater monitoring; interstitial monitoring of double containment systems; and vapor monitoring

  3. Non-destructive testing. The current state of standards and qualification and certification for leak testing

    International Nuclear Information System (INIS)

    Tamura, Yoshikazu

    2011-01-01

    Domestic standards of the leak testing are enacted as one of Japan Industrial Standards. The conformity is advanced between these domestic standards and ISO (International Organization for Standardization) standard. ISO9712 (Non-destructive testing-Qualification and certification of personnel) was revised to include the leak testing of qualification and certification in 2005. The preparation working group of qualification and certification for leak testing is planning start aiming at the system in one and a half years. (author)

  4. Proton: the particle.

    Science.gov (United States)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

  5. Proton: The Particle

    Energy Technology Data Exchange (ETDEWEB)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  6. Mapping urban pipeline leaks: Methane leaks across Boston

    International Nuclear Information System (INIS)

    Phillips, Nathan G.; Ackley, Robert; Crosson, Eric R.; Down, Adrian; Hutyra, Lucy R.; Brondfield, Max; Karr, Jonathan D.; Zhao Kaiguang; Jackson, Robert B.

    2013-01-01

    Natural gas is the largest source of anthropogenic emissions of methane (CH 4 ) in the United States. To assess pipeline emissions across a major city, we mapped CH 4 leaks across all 785 road miles in the city of Boston using a cavity-ring-down mobile CH 4 analyzer. We identified 3356 CH 4 leaks with concentrations exceeding up to 15 times the global background level. Separately, we measured δ 13 CH 4 isotopic signatures from a subset of these leaks. The δ 13 CH 4 signatures (mean = −42.8‰ ± 1.3‰ s.e.; n = 32) strongly indicate a fossil fuel source rather than a biogenic source for most of the leaks; natural gas sampled across the city had average δ 13 CH 4 values of −36.8‰ (±0.7‰ s.e., n = 10), whereas CH 4 collected from landfill sites, wetlands, and sewer systems had δ 13 CH 4 signatures ∼20‰ lighter (μ = −57.8‰, ±1.6‰ s.e., n = 8). Repairing leaky natural gas distribution systems will reduce greenhouse gas emissions, increase consumer health and safety, and save money. Highlights: ► We mapped 3356 methane leaks in Boston. ► Methane leaks in Boston carry an isotopic signature of pipeline natural gas. ► Replacing failing gas pipelines will provide safety, environmental, and economic benefits. - We identified 3356 methane leaks in Boston, with isotopic characteristics consistent with pipeline natural gas.

  7. Mitigated Transfer Line Leaks that Result in Surface Pools and Spray Leaks into Pits

    Energy Technology Data Exchange (ETDEWEB)

    HEY, B.E.

    1999-12-07

    This analysis provides radiological and toxicological consequence calculations for postulated mitigated leaks during transfers of six waste compositions. Leaks in Cleanout Boxes equipped with supplemental covers and leaks in pits are analyzed.

  8. Mitigated Transfer Line Leaks that Result in Surface Pools and Spray Leaks into Pits

    International Nuclear Information System (INIS)

    HEY, B.E.

    1999-01-01

    This analysis provides radiological and toxicological consequence calculations for postulated mitigated leaks during transfers of six waste compositions. Leaks in Cleanout Boxes equipped with supplemental covers and leaks in pits are analyzed

  9. The ISS 2B PVTCS Ammonia Leak: An Operational History

    Science.gov (United States)

    Vareha, Anthony

    2014-01-01

    In 2006, the Photovoltaic Thermal Control System (PVTCS) for the International Space Station's 2B power channel began leaking ammonia at a rate of approximately 1.5lbm/year (out of a starting approximately 53lbm system ammonia mass). Initially, the operations strategy was "feed the leak," a strategy successfully put into action via Extra Vehicular Activity during the STS-134 mission. During this mission the system was topped off with ammonia piped over from a separate thermal control system. This recharge was to have allowed for continued power channel operation into 2014 or 2015, at which point another EVA would have been required. Without these periodic EVAs to refill the 2B coolant system, the channel would eventually leak enough fluid as to risk pump cavitation and system failure, resulting in the loss of the 2B power channel - the most critical of the Space Station's 8 power channels. In mid-2012, the leak rate increased to approximately 5lbm/year. Once discovered, an EVA was planned and executed within a 5 week timeframe to drastically alter the architecture of the PVTCS via connection to a dormant thermal control system not intended to be utilized as anything other than spare components. The purpose of this rerouting of the TCS was to increase system volume and to isolate the photovoltaic radiator, thought to be the likely leak source. This EVA was successfully executed on November 1st, 2012 and left the 2B PVTCS in a configuration where the system was now being adequately cooled via a totally different radiator than what the system was designed to utilize. Unfortunately, data monitoring over the next several months showed that the isolated radiator was not leaking, and the system itself continued to leak steadily until May 9th, 2013. It was on this day that the ISS crew noticed the visible presence of ammonia crystals escaping from the 2B channel's truss segment, signifying a rapid acceleration of the leak from 5lbm/year to 5lbm/day. Within 48 hours of the

  10. Detecting leaks in vacuum bags

    Science.gov (United States)

    Carlstrom, E. E.

    1980-01-01

    Small leaks in vacuum bag can be readily detected by eye, using simple chemical reaction: combination of ammonia and acetic acid vapors to produce cloudy white smoke. Technique has been successfully used to test seam integrity and to identify minute pinholes in vacuum bag used in assembly of ceramic-tile heat shield for Space Shuttle Orbiter.

  11. LOCATING LEAKS WITH ACOUSTIC TECHNOLOGY

    Science.gov (United States)

    Many water distribution systems in this country are almost 100 years old. About 26 percent of piping in these systems is made of unlined cast iron or steel and is in poor condition. Many methods that locate leaks in these pipes are time-consuming, costly, disruptive to operations...

  12. Pipe Leak Detection Technology Development

    Science.gov (United States)

    The U. S. Environmental Protection Agency (EPA) has determined that one of the nation’s biggest infrastructural needs is the replacement or rehabilitation of the water distribution and transmission systems. The institution of more effective pipe leak detection technology will im...

  13. Reliability of leak detection systems in LWRs

    International Nuclear Information System (INIS)

    Kupperman, D.S.

    1986-10-01

    In this paper, NRC guidelines for leak detection will be reviewed, current practices described, potential safety-related problems discussed, and potential improvements in leak detection technology (with emphasis on acoustic methods) evaluated

  14. Stochastic Consequence Analysis for Waste Leaks

    International Nuclear Information System (INIS)

    HEY, B.E.

    2000-01-01

    This analysis evaluates the radiological consequences of potential Hanford Tank Farm waste transfer leaks. These include ex-tank leaks into structures, underneath the soil, and exposed to the atmosphere. It also includes potential misroutes, tank overflow

  15. Simulation of leaking fuel rods

    International Nuclear Information System (INIS)

    Hozer, Z.

    2006-01-01

    The behaviour of failed fuel rods includes several complex phenomena. The cladding failure initiates the release of fission product from the fuel and in case of large defect even urania grains can be released into the coolant. In steady state conditions an equilibrium - diffusion type - release is expected. During transients the release is driven by a convective type leaching mechanism. There are very few experimental data on leaking WWER fuel rods. For this reason the activity measurements at the nuclear power plants provide very important information. The evaluation of measured data can help in the estimation of failed fuel rod characteristics and the prediction of transient release dynamics in power plant transients. The paper deals with the simulation of leaking fuel rods under steady state and transient conditions and describes the following new results: 1) A new algorithm has been developed for the simulation of leaking fuel rods under steady state conditions and the specific parameters of the model for the Paks NPP has been determined; 2) The steady state model has been applied to calculation of leaking fuel characteristics using iodine and noble gas activity measurement data; 3) A new computational method has been developed for the simulation of leaking fuel rods under transient conditions and the specific parameters for the Paks NPP has been determined; 4) The transient model has been applied to the simulation of shutdown process at the Paks NPP and for the prediction of the time and magnitude of 123 I activity peak; 5) Using Paks NPP data a conservative value has been determined for the upper limit of the 123 I release from failed fuel rods during transients

  16. Imaging review of cerebrospinal fluid leaks

    OpenAIRE

    Naga V Vemuri; Lakshmi S P Karanam; Venkatesh Manchikanti; Srinivas Dandamudi; Sampath K Puvvada; Vineet K Vemuri

    2017-01-01

    Cerebrospinal fluid (CSF) leak occurs due to a defect in the dura and skull base. Trauma remains the most common cause of CSF leak; however, a significant number of cases are iatrogenic, and result from a complication of functional endoscopic sinus surgery (FESS). Early diagnosis of CSF leak is of paramount importance to prevent life-threatening complications such as brain abscess and meningitis. Imaging plays a crucial role in the detection and characterization of CSF leaks. Three-dimensiona...

  17. Helium leak testing methods in nuclear applications

    International Nuclear Information System (INIS)

    Ahmad, Anis

    2004-01-01

    Helium mass-spectrometer leak test is the most sensitive leak test method. It gives very reliable and sensitive test results. In last few years application of helium leak testing has gained more importance due to increased public awareness of safety and environment pollution caused by number of growing chemical and other such industries. Helium leak testing is carried out and specified in most of the critical area applications like nuclear, space, chemical and petrochemical industries

  18. Calibration of a leak detection spectrometer

    International Nuclear Information System (INIS)

    Geller, R.

    1958-01-01

    This paper describes a study of the possible methods for calibrating a leak detection spectrometer, and the estimation of outputs from the leaks is considered. With this in mind the question of sensitivity of leak detection is tackled on a very general level; first the sensitivity of the isolated instrument is determined, and then the sensitivity of an instrument connected to an installation where leaks may be suspected. Finally, practical solutions are proposed. (author) [fr

  19. In vivo measurements of cerebral metabolic abnormalities by proton spectroscopy after a transient ischemic attack revealing an internal carotid stenosis > 70%

    International Nuclear Information System (INIS)

    Giroud, M.; Becker, F.; Lemesle, M.; Walker, P.; Guy, F.; Martin, D.; Baudouin, N.; Brunotte, F.; Dumas, R.

    1996-01-01

    Aims: The aim of this work is to look for cerebral metabolic abnormalities within the first 3 days after a transient ischemic attack revealing an internal carotid stenosis > 70 %. Methods: Five patients with a transient ischemic attack lasting between 30 and 180 minutes, affecting sensory and motor brachio-facial territory, with or without aphasia. Were studied. A CT-scan, an EEG, a cervical Doppler ultrasound, a standard arteriography, a magnetic resonance imaging and a proton spectroscopy were performed within the cerebral area affected by the transient ischemic attack. We measured 2 markers: N-acetyl-aspartate, the marker of the neuronal mass, and lactate, the marker of anaerobe metabolism. In each case, a contralateral internal stenosis was diagnosed by cervical Doppler ultrasound and standard arteriography. No cerebral infarction was observed. Results: With the affected cerebral area defined according to clinical and EEG features, proton spectroscopy showed a significant rise of lactate, without any change in N-acetyl-aspartate levels. Conclusions: Within the first 3 days after a transient ischemic attack, there is a significant risk of lactate inside the affected cerebral area. This change may reflect a localized and transient hypoperfusion, but long enough to induce a rise of lactate but not sufficient to produce a cerebral infarct. This area is probably at risk to induce cerebral infarct. This data lead us to study the metabolic change induced by the asymptomatic internal carotid stenosis. (authors). 18 refs

  20. Intraoperative leak testing has no correlation with leak after laparoscopic sleeve gastrectomy.

    Science.gov (United States)

    Sethi, Monica; Zagzag, Jonathan; Patel, Karan; Magrath, Melissa; Somoza, Eduardo; Parikh, Manish S; Saunders, John K; Ude-Welcome, Aku; Schwack, Bradley F; Kurian, Marina S; Fielding, George A; Ren-Fielding, Christine J

    2016-03-01

    Staple line leak is a serious complication of sleeve gastrectomy. Intraoperative methylene blue and air leak tests are routinely used to evaluate for leak; however, the utility of these tests is controversial. We hypothesize that the practice of routine intraoperative leak testing is unnecessary during sleeve gastrectomy. A retrospective cohort study was designed using a prospectively collected database of seven bariatric surgeons from two institutions. All patients who underwent sleeve gastrectomy from March 2012 to November 2014 were included. The performance of intraoperative leak testing and the type of test (air or methylene blue) were based on surgeon preference. Data obtained included BMI, demographics, comorbidity, presence of intraoperative leak test, result of test, and type of test. The primary outcome was leak rate between the leak test (LT) and no leak test (NLT) groups. SAS version 9.4 was used for univariate and multivariate analyses. A total of 1550 sleeve gastrectomies were included; most were laparoscopic (99.8%), except for one converted and two open cases. Routine intraoperative leak tests were performed in 1329 (85.7%) cases, while 221 (14.3%) did not have LTs. Of the 1329 cases with LTs, there were no positive intraoperative results. Fifteen (1%) patients developed leaks, with no difference in leak rate between the LT and NLT groups (1 vs. 1%, p = 0.999). After adjusting for baseline differences between the groups with a propensity analysis, the observed lack of association between leak and intraoperative leak test remained. In this cohort, leaks presented at a mean of 17.3 days postoperatively (range 1-67 days). Two patients with staple line leaks underwent repeat intraoperative leak testing at leak presentation, and the tests remained negative. Intraoperative leak testing has no correlation with leak due to laparoscopic sleeve gastrectomy and is not predictive of the later development of staple line leak.

  1. Localization of a sound source in in a guided medium and reverberating field. Contribution to a study on leak localization in the internal wall of containment of a nuclear reactor in the case of a severe reactor accident; Localisation d`une source acoustique en milieu guide et champ reverberant. Contribution a l`etude sur la localisation de fuite de l`enceinte de confinement d`une centrale nucleaire en situation accidentelle grave

    Energy Technology Data Exchange (ETDEWEB)

    Thomann, F

    1996-11-28

    Basic data necessary for the localization of a leak in the internal wall of the containment are presented by studying the sound generated by gas jets coming out of (leaking fissures) as well as propagation in a guided medium. The results acquired have led us to choose the simple intercorrelation method and the matched filed processing method, both of which are likely to adequately handle our problems. Whereas the intercorrelation method appears to be limited in scope when dealing in the guided medium, the matched field processing is suited to leak localization over a surface of approximately 1000 m{sup 2} (for a total surface of 10 000 m{sup 2}). Preliminary studies on the leak signal and on replicated signals have led us to limit the frequency band to 2600 - 3000 Hz. We have succeeded in locating a leak situated in an ordinary position with a minimum amount of replicated signals and basic data. We have improved on the estimation of Bartlett and MVDE (minimum variance distortion less filter) rendering them even more effective. Afterwards, we considered the severe accident situation and showed that the system can be installed in situ. (author) 88 refs.

  2. ATLAS Forward Proton Detector - Offline Data Quality Monitoring, Time of Flight Efficiency and Internal Alignment

    CERN Document Server

    Hohmann, Marcel

    2017-01-01

    The ATLAS Forward proton Detector (AFP) aims to study diffractive events where protons are scattered at an angle of the order of several microradians from the beamlines.The AFP consists of four stations, two near stations located 205m either side of the ATLAS interaction point (IP1) and two far stations located 217m either side of IP1 (Figure 1). Each station consists of a Roman Pot containing a Silicon tracker (SiT) with the far stations having an additional Time of Flight (ToF) detector. The AFP is still commissioning with the full 2+2 configuration, that is two stations on each side of ATLAS, having only recently been installed during the winter 2016/2017 technical shutdown. There is still significant work to be done on data quality before physics analysis can begin.

  3. Nuclear fuel element leak detection system

    International Nuclear Information System (INIS)

    John, C.D. Jr.

    1978-01-01

    Disclosed is a leak detection system integral with a wall of a building used to fabricate nuclear fuel elements for detecting radiation leakage from the nuclear fuel elements as the fuel elements exit the building. The leak detecting system comprises a shielded compartment constructed to withstand environmental hazards extending into a similarly constructed building and having sealed doors on both ends along with leak detecting apparatus connected to the compartment. The leak detecting system provides a system for removing a nuclear fuel element from its fabrication building while testing for radiation leaks in the fuel element

  4. Leak testing and repair of fusion devices

    International Nuclear Information System (INIS)

    Kozman, T.A.

    1983-01-01

    The leak testing, reporting and vacuum leak repair techniques of the MFTF yin-yang number one magnet system, the world's largest superconducting magnet system, are discussed. Based on this experience, techniques will be developed for testing and repairing leaks on the 42 MFTF-B magnets. The leak-hunting techniques for the yin-yang magnet systems were applied to two helium circuits (the coil bundle and guard vacuum; both require helium flow for magnet cooldown), their associated piping, liquid nitrogen radiation shields, and piping. Additionally, during MFTF-B operation there will be warm water plasma shields and piping that require leak checking

  5. Leak rate measurements and detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.; Shack, W.J.; Claytor, T.

    1983-10-01

    A research program is under way to evaluate and develop improve leak detection systems. The primary focus of the work has been on acoustic emission detection of leaks. Leaks from artificial flaws, laboratory-generated IGSCCs and thermal fatigue cracks, and field-induced intergranular stress corrosion cracks (IGSCCs) from reactor piping have been examined. The effects of pressure, temperature, and leak rate and geometry on the acoustic signature are under study. The use of cross-correlation techniques for leak location and pattern recognition and autocorrelation for source discrimination is also being considered

  6. Leak detection by vibrational diagnostic methods

    International Nuclear Information System (INIS)

    Siklossy, P.

    1983-01-01

    The possibilities and methods of leak detection due to mechanical failures in nuclear power plants are reviewed on the basis of the literature. Great importance is attributed to vibrational diagnostic methods for their adventageous characteristics which enable them to become final leak detecting methods. The problems of noise analysis, e.g. leak detection by impact sound measurements, probe characteristics, gain problems, probe selection, off-line analysis and correlation functions, types of leak noises etc. are summarized. Leak detection based on noise analysis can be installed additionally to power plants. Its maintenance and testing is simple. On the other hand, it requires special training and measuring methods. (Sz.J.)

  7. Leak testing. Environment and workplaces

    International Nuclear Information System (INIS)

    1984-01-01

    Workplaces specified for leak testing are divided into clean workplaces of the 1st degree, clean workplaces of the second degree, clean workplaces of the third degree and semi-clean workplaces. Clean workplaces are further subdivided into permanent and temporary workplaces. For all said types of workplaces the standard sets the following provisions: basic equipment, machines and instrumentation, permitted and prohibited working activities and principles for maintenance and inspection. (E.S.)

  8. Hydrogen Leak Detection Sensor Database

    Science.gov (United States)

    Baker, Barton D.

    2010-01-01

    This slide presentation reviews the characteristics of the Hydrogen Sensor database. The database is the result of NASA's continuing interest in and improvement of its ability to detect and assess gas leaks in space applications. The database specifics and a snapshot of an entry in the database are reviewed. Attempts were made to determine the applicability of each of the 65 sensors for ground and/or vehicle use.

  9. Repair of EL4 leaks

    International Nuclear Information System (INIS)

    1985-03-01

    The reactor shutdown was decided on the 15th of November 1984, because the evolution of the carbon dioxide quantity in the helium blanket of the heavy water. Leaks have been localized on three different channels. Repairs have been made in hard conditions taking into account the reactor state (materials strongly irradiated). The restart has been authorized on the 24th of January 1985 [fr

  10. Development of sodium leak detectors for PFBR

    International Nuclear Information System (INIS)

    Sylvia, J.I.; Rao, P. Vijayamohana; Babu, B.; Madhusoodanan, K.; Rajan, K.K.

    2012-01-01

    Highlights: ► Sodium leak detection system developed for PFBR using diverse principle. ► Miniature, remotely locatable diverse leak detector developed for Main Vessel. ► Mutual inductance type leak detectors designed and adapted for different locations. ► Sodium Ionisation detectors used for area monitoring. ► Crosswire type leak detector designed, developed and tested. - Abstract: The 500 MWe Prototype Fast Breeder Reactor (PFBR) is under advanced stage of construction at Kalpakkam near Chennai in India. The wide and high operating temperature, highly chemically active nature of sodium and its reaction with air make the sodium instrumentation complex over the conventional instrumentation. Over the years, traditional instruments such as wire type leak detectors, spark plug type leak detectors were developed and used in different sodium systems. The redundant and diverse leak detection method calls for development of special instrumentation for sodium systems which include sodium ionization (leak) detector for detecting minute sodium leak in addition to those systems based on mutual inductance principle. For detection of sodium leak from reactor Main Vessel (MV), diverse methods are used such as miniature, remotely locatable, Mutual Inductance type Leak Detector(MILD) and specially modified spark plug type leak detector. The design of MILD is suitably modified for detecting leak in double wall pipes and Diverse Safety Rod drive Mechanism (DSRDM). Steam/water leak in steam generator produces hydrogen and leads to high pressure and temperature in the system. Rupture disc is used as a safety device which punctures itself due to sudden pressure rise. To detect the discharge of sodium and its reaction products at the downstream of the rupture disc due to bursting of the rupture disc, cross wire type leak detector has been designed, developed and tested. The selection of the leak detection system depends on the location where leak has to be detected. This paper

  11. Study of coupled heat and water transfer in proton exchange membrane fuel cells by the way of internal measurements

    International Nuclear Information System (INIS)

    Thomas, A; Maranzana, G; Didierjean, S; Dillet, J; Lottin, O

    2012-01-01

    Measurements of electrode temperatures within a proton exchange membrane fuel cell were performed using platinum wires. A temperature difference of 7°C between the electrodes and the bipolar plates was observed for a cell operating at a current density of 1.5 A.cm −2 . These measurements show a strong non-uniformity of the temperature profile through membrane electrode assembly (MEA) that future phenomenological models must take into account. In addition, the simultaneous measurements of heat and water flux through the MEA leads to the conclusion that produced water crosses the diffusion layer in vapor phase. A very simple heat transfer model is proposed.

  12. Leak detection capability in CANDU reactors

    International Nuclear Information System (INIS)

    Azer, N.; Barber, D.H.; Boucher, P.J.

    1997-01-01

    This paper addresses the moisture leak detection capability of Ontario Hydro CANDU reactors which has been demonstrated by performing tests on the reactor. The tests confirmed the response of the annulus gas system (AGS) to the presence of moisture injected to simulate a pressure tube leak and also confirmed the dew point response assumed in leak before break assessments. The tests were performed on Bruce A Unit 4 by injecting known and controlled rates of heavy water vapor. To avoid condensation during test conditions, the amount of moisture which could be injected was small (2-3.5 g/hr). The test response demonstrated that the AGS is capable of detecting and annunciating small leaks. Thus confidence is provided that it would alarm for a growing pressure tube leak where the leak rate is expected to increase to kg/hr rapidly. The measured dew point response was close to that predicted by analysis

  13. Leak detection capability in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Azer, N.; Barber, D.H.; Boucher, P.J. [and others

    1997-04-01

    This paper addresses the moisture leak detection capability of Ontario Hydro CANDU reactors which has been demonstrated by performing tests on the reactor. The tests confirmed the response of the annulus gas system (AGS) to the presence of moisture injected to simulate a pressure tube leak and also confirmed the dew point response assumed in leak before break assessments. The tests were performed on Bruce A Unit 4 by injecting known and controlled rates of heavy water vapor. To avoid condensation during test conditions, the amount of moisture which could be injected was small (2-3.5 g/hr). The test response demonstrated that the AGS is capable of detecting and annunciating small leaks. Thus confidence is provided that it would alarm for a growing pressure tube leak where the leak rate is expected to increase to kg/hr rapidly. The measured dew point response was close to that predicted by analysis.

  14. Acoustic leak detection of LMFBR steam generator

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Yoshida, Kazuo

    1993-01-01

    The development of a water leak detector with short response time for LMFBR steam generators is required to prevent the failure propagation caused by the sodium-water reaction and to maintain structural safety in steam generators. The development of an acoustic leak detector assuring short response time has attracted. The purpose of this paper is to confirm the basic detection feasibility of the active acoustic leak detector, and to investigate the leak detection method by erasing the background noise by spectrum analysis of the passive acoustic leak detector. From a comparison of the leak detection sensitivity of the active and the passive method, the active method is not influenced remarkably by the background noise, and it has possibility to detect microleakage with short response time. We anticipate a practical application of the active method in the future. (author)

  15. Paravalvular Leak in Structural Heart Disease.

    Science.gov (United States)

    Goel, Kashish; Eleid, Mackram F

    2018-03-06

    This review will summarize the growing importance of diagnosing and managing paravalvular leak associated with surgical and transcatheter valves. The burden of paravalvular leak is increasing; however, advanced imaging techniques and high degree of clinical suspicion are required for diagnosis and management. The latest data from pivotal clinical trials in the field of transcatheter aortic valve replacement suggest that any paravalvular leak greater than mild was associated with worse clinical outcomes. Percutaneous techniques for paravalvular leak closure are now the preferred approach, and surgical repair is reserved for contraindications and unsuccessful procedures. Recent data from studies evaluating paravalvular leak closure outcomes report a greater than 90% success rate with a significant improvement in patient symptoms. Paravalvular leak is a growing problem in the structural heart disease arena. Percutaneous closure is successful in more than 90% of the procedures with a low complication rate.

  16. Hermetic compartments leak-tightness enhancement

    International Nuclear Information System (INIS)

    Murani, J.

    2000-01-01

    In connection with the enhancement of the nuclear safety of the Jaslovske Bohunice V-1 NPP actions for the increase of the leak tightness are performed. The reconstruction has been done in the following directions: hermetic compartments leak tightness enhancement; air lock installation; installation of air lock in SP 4 vent system; integrated leakage rate test to hermetic compartments with leak detection. After 'major' leaks on the hermetic boundary components had been eliminated, since 1994 works on a higher qualitative level began. The essence of the works consists in the detection and identification of leaks in the structural component of the hermetic boundary during the planned refueling outages. The results of the Small Reconstruction and gradual enhancement of leak tightness are presented

  17. Analyzing User Awareness of Privacy Data Leak in Mobile Applications

    Directory of Open Access Journals (Sweden)

    Youngho Kim

    2015-01-01

    Full Text Available To overcome the resource and computing power limitation of mobile devices in Internet of Things (IoT era, a cloud computing provides an effective platform without human intervention to build a resource-oriented security solution. However, existing malware detection methods are constrained by a vague situation of information leaks. The main goal of this paper is to measure a degree of hiding intention for the mobile application (app to keep its leaking activity invisible to the user. For real-world application test, we target Android applications, which unleash user privacy data. With the TaintDroid-ported emulator, we make experiments about the timing distance between user events and privacy leaks. Our experiments with Android apps downloaded from the Google Play show that most of leak cases are driven by user explicit events or implicit user involvement which make the user aware of the leakage. Those findings can assist a malware detection system in reducing the rate of false positive by considering malicious intentions. From the experiment, we understand better about app’s internal operations as well. As a case study, we also presents a cloud-based dynamic analysis framework to perform a traffic monitor.

  18. Optical properties behavior of three optical filters and a mirror used in the internal optical head of a Raman laser spectrometer after exposed to proton radiation

    Science.gov (United States)

    Guembe, V.; Alvarado, C. G.; Fernández-Rodriguez, M.; Gallego, P.; Belenguer, T.; Díaz, E.

    2017-11-01

    The Raman Laser Spectrometer is one of the ExoMars Pasteur Rover's payload instruments that is devoted to the analytical analysis of the geochemistry content and elemental composition of the observed minerals provided by the Rover through Raman spectroscopy technique. One subsystem of the RLS instrument is the Internal Optical Head unit (IOH), which is responsible for focusing the light coming from the laser onto the mineral under analysis and for collecting the Raman signal emitted by the excited mineral. The IOH is composed by 4 commercial elements for Raman spectroscopy application; 2 optical filters provided by Iridian Spectral Technologies Company and 1 optical filter and 1 mirror provided by Semrock Company. They have been exposed to proton radiation in order to analyze their optical behaviour due to this hostile space condition. The proton irradiation test was performed following the protocol of LINES lab (INTA). The optical properties have been studied through transmittance, reflectance and optical density measurements, the final results and its influence on optical performances are presented.

  19. Benign Biliary Strictures and Leaks.

    Science.gov (United States)

    Devière, Jacques

    2015-10-01

    The major causes of benign biliary strictures include surgery, chronic pancreatitis, primary sclerosing cholangitis, and autoimmune cholangitis. Biliary leaks mainly occur after surgery and, rarely, abdominal trauma. These conditions may benefit from a nonsurgical approach in which endoscopic retrograde cholangiopancreatography (ERCP) plays a pivotal role in association with other minimally invasive approaches. This approach should be evaluated for any injury before deciding about the method for repair. ERCP, associated with peroral cholangioscopy, plays a growing role in characterizing undeterminate strictures, avoiding both unuseful major surgeries and palliative options that might compromise any further management. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Leak detection of KNI seals

    International Nuclear Information System (INIS)

    Baranyai, G.; Peter, A.; Windberg, P.

    1990-03-01

    In Unit 3 and 4 of the Paks Nuclear Power Plant, Hungary, KNI type seals are used as lead-throughs with conical nickel sealing rings. Their failure can be critical for the operation of the reactor. An Acoustical Leak Detection System (ALDS) was constructed and tested for the operational testing of the seals. Some individual papers are presented in this collection on the calibration and testing of the ALDS intended to be placed on the top of the reactor vessels. The papers include simulation measurements of Unit 3 of NPP, laboratory experiments, evaluation of measurements, and further development needs with the ALDS. (R.P.) 50 figs.; 19 tabs

  1. Vacuum leak detector and method

    Science.gov (United States)

    Edwards, Jr., David

    1983-01-01

    Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

  2. Aviation investigation report : hard landing : fuel leak and fire[Sundance Balloons International Firefly 12B (hot air balloon) C-FNVM, Winnipeg, Manitoba, 15 nm NE, 11 August 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-08-15

    This investigation report discussed an incident in Winnipeg in which a hot air balloon attempting to land during strong winds was dragged on its side for approximately 700 feet. The balloon's burners struck the ground as the balloon came to a stop, after which a propane leak occurred. An intense, uncontrolled fire ensued as balloon passengers were exiting from the partially-inverted basket. The pilot and 2 passengers suffered serious injuries, while another 4 passengers suffered minor injuries. The balloon's 2 propane tanks and a fire extinguisher canister exploded during the fire, which destroyed the balloon's basket. The rigging of the balloon was examined and no failures were discovered. Pressure tests showed that the balloon's hoses started leaking at the crimped sleeve fittings at 150 psi. While the pilot had been informed of potentially heavy winds and thunderstorms, changes in wind speed and direction occurred earlier than the forecasted time of 10:00. It was concluded that standards are needed to ensure balloon cabin safety. Balloon operators do not currently require the use of protective helmets or gloves in case of dragged landings. A review will be conducted to address the issue of proposed emergency fuel shut-offs for balloons carrying fare-paying passengers. 2 figs.

  3. Influence of wetting effect at the outer surface of the pipe on increase in leak rate - experimental results and discussion

    Energy Technology Data Exchange (ETDEWEB)

    Isozaki, Toshikuni; Shibata, Katsuyuki

    1997-04-01

    Experimental and computed results applicable to Leak Before Break analysis are presented. The specific area of investigation is the effect of the temperature distribution changes due to wetting of the test pipe near the crack on the increase in the crack opening area and leak rate. Two 12-inch straight pipes subjected to both internal pressure and thermal load, but not to bending load, are modelled. The leak rate was found to be very susceptible to the metal temperature of the piping. In leak rate tests, therefore, it is recommended that temperature distribution be measured precisely for a wide area.

  4. Acoustic emission leak monitoring system LMS-96

    International Nuclear Information System (INIS)

    Liska, J.; Cvrcek, M.; Mueller, L.

    1997-01-01

    On-line acoustic emission leak monitoring under industrial conditions of nuclear power plants is a problem with specific features setting specific demands on the leak monitoring system. The paper briefly reviews those problems (attenuation pattern of a real structure, acoustic background, alarm system, etc.) and the solution of some of them is discussed. Information is presented on the Acoustic Emission Leak Monitoring System LMS-96 by SKODA NUCLEAR MACHINERY and the system's function is briefly described. (author)

  5. Leak detection using structure-borne noise

    Science.gov (United States)

    Holland, Stephen D. (Inventor); Chimenti, Dale E. (Inventor); Roberts, Ronald A. (Inventor)

    2010-01-01

    A method for detection and location of air leaks in a pressure vessel, such as a spacecraft, includes sensing structure-borne ultrasound waveforms associated with turbulence caused by a leak from a plurality of sensors and cross correlating the waveforms to determine existence and location of the leak. Different configurations of sensors and corresponding methods can be used. An apparatus for performing the methods is also provided.

  6. Hepatobiliary scintigraphy in patients with bile leaks

    International Nuclear Information System (INIS)

    Carichner, S.L.; Nagle, C.E.

    1987-01-01

    Hepatobiliary scintigraphy has been recognized as a useful tool in detecting the presence and sites of bile leaks. The clinical settings in which bile leaks are likely to occur, as well as some of the scintigraphic patterns seen in patients with bile leaks, are reviewed here. Tips for technologists are offered on interventions that might enhanced the quality of information available to the nuclear physician

  7. Analysis of leak and break behavior in a failure assessment diagram for carbon steel pipes

    International Nuclear Information System (INIS)

    Kanno, Satoshi; Hasegawa, Kunio; Shimizu, Tasuku; Saitoh, Takashi; Gotoh, Nobuho

    1992-01-01

    The leak and break behavior of a cracked coolant pipe subjected to an internal pressure and a bending moment was analyzed with a failure assessment diagram using the R6 approach. This paper examines the conditions of the detectable coolant leakage without breakage. A leakage assessment curve, a locus of assessment point for detectable coolant leakage, was defined in the failure assessment diagram. The region between the leak assessment and failure assessment curves satisfies the condition of detectable leakage without breakage. In this region, a crack can be safely inspected by a coolant leak detector. (orig.)

  8. Proton therapy

    International Nuclear Information System (INIS)

    Smith, Alfred R

    2006-01-01

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

  9. Acoustic surveillance techniques for SGU leak monitoring

    International Nuclear Information System (INIS)

    McKnight, J.A.; Rowley, R.; Beesley, M.J.

    1990-01-01

    The paper presents a brief review of the acoustic techniques applicable to the detection of steam generator unit leaks that have been studied in the UK. Before discussion of the acoustic detection methods a reference representation of the required performance as developed in the UK is given. The conclusion is made that preliminary specification for the acoustic leak detection of sodium/water leaks in steam generating units suggests that it will be necessary to detect better than a leak rate of 3 g/s within a few seconds. 10 refs, 12 figs

  10. Leak behaviors of steam generator tube-to-tubesheet joints from room temperature to 320 °C

    International Nuclear Information System (INIS)

    Bahn, Chi Bum; Majumdar, Saurin; Kasza, Ken E.; Shack, William J.

    2013-01-01

    To address concerns about excessive leakage from throughwall cracks in nuclear reactor tube-to-tubesheet joints under accident conditions, leak rates were measured experimentally by using tube-to-collar joint specimens and nitrogen gas. Rates were dependent on differential pressure between the tube internal surface and the crevice (i.e., the tube-to-collar interface region) and on temperature. As specimen temperature was raised to 320 °C, leak rates decreased gradually due to changes in gas properties and to differential thermal expansion between the Alloy 600 tubes and the SA508 collars. The leak rates did not change even after repeated temperature excursions to 320 °C, suggesting that thermally induced creep and subsequent contact pressure relaxation is negligible below that temperature. When considering factors that could increase flow resistance, such as oxidation, or debris on top of the tubesheet, the measured leak rates in this work are considered to be conservative. The test results were further used to validate the contact pressure calculation and a leak rate model. Highlights: ► Leak rates were measured by using tube-to-collar joint specimens. ► Leak rates were dependent on differential pressure between tube internal and joint interface. ► Leak rates decreased gradually as specimen temperature was raided to 320 °C. ► Differential thermal expansion between Alloy 600 tube and SA508 collar plays a major role on the leak behavior.

  11. The discrimination between cosmic positrons and protons with the Transition Radiation Detector of the AMS experiment on the International Space Station

    International Nuclear Information System (INIS)

    Millinger, Mark

    2012-01-01

    positron fraction up to particle momenta less or equal to 1 TeV. The combination of electromagnetic calorimeter (ECAL) and TRD is necessary to provide the high proton suppression factor at high momenta. This work describes the particle identification with the TRD and evaluates its performance on pre-selected events from a dataset taken on the International Space Station and from data, which have been recorded in a beamtest before the transport to the space station. The necessary algorithms, starting from event reconstruction through detector calibration up to particle identification are discussed. The TRD independent event pre-selection is used to determine the sea-level muon flux by the combination of muon event rate, as recorded on ground at Kennedy Space Center, and detector acceptance, extracted from simulations. Additionally, low-energy data recorded on the International Space Station is used to investigate the geomagnetic field. Here, the rigidity cutoff, below which particles are deflected by the geomagnetic field too much to reach the detector, is determined as function of geodetic latitude and longitude. The performance of the TRD event reconstruction on pre-selected data event samples is compared to simulations. The efficiency of consecutive reconstruction steps, assigned to geometric effects, event reconstruction, quality selection and matching of tracks is determined. The energy depositions on a track are used to disentangle lepton and proton events. Calibration algorithms are introduced to provide invariant energy deposition signal by correcting for the signal variation due to gas gain, path length and particle momentum. The performance of the calibration algorithms is evaluated by signal stability studies and their impact on the TRD particle identification performance. The TRD efficiency and proton suppression studies performed in this work are crucial steps towards the precise measurement of cosmic lepton fluxes and the cosmic positron fraction.

  12. The discrimination between cosmic positrons and protons with the Transition Radiation Detector of the AMS experiment on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Millinger, Mark

    2012-10-08

    of the cosmic positron fraction up to particle momenta less or equal to 1 TeV. The combination of electromagnetic calorimeter (ECAL) and TRD is necessary to provide the high proton suppression factor at high momenta. This work describes the particle identification with the TRD and evaluates its performance on pre-selected events from a dataset taken on the International Space Station and from data, which have been recorded in a beamtest before the transport to the space station. The necessary algorithms, starting from event reconstruction through detector calibration up to particle identification are discussed. The TRD independent event pre-selection is used to determine the sea-level muon flux by the combination of muon event rate, as recorded on ground at Kennedy Space Center, and detector acceptance, extracted from simulations. Additionally, low-energy data recorded on the International Space Station is used to investigate the geomagnetic field. Here, the rigidity cutoff, below which particles are deflected by the geomagnetic field too much to reach the detector, is determined as function of geodetic latitude and longitude. The performance of the TRD event reconstruction on pre-selected data event samples is compared to simulations. The efficiency of consecutive reconstruction steps, assigned to geometric effects, event reconstruction, quality selection and matching of tracks is determined. The energy depositions on a track are used to disentangle lepton and proton events. Calibration algorithms are introduced to provide invariant energy deposition signal by correcting for the signal variation due to gas gain, path length and particle momentum. The performance of the calibration algorithms is evaluated by signal stability studies and their impact on the TRD particle identification performance. The TRD efficiency and proton suppression studies performed in this work are crucial steps towards the precise measurement of cosmic lepton fluxes and the cosmic positron

  13. In vivo measurements of cerebral metabolic abnormalities by proton spectroscopy after a transient ischemic attack revealing an internal carotid stenosis > 70%; Anomalies metaboliques cerebrales mesurees in vivo par la spectroscopie du proton dans les accidents ischemiques transitoires revelant une stenose de la carotide interne superieure a 70%

    Energy Technology Data Exchange (ETDEWEB)

    Giroud, M.; Becker, F.; Lemesle, M.; Walker, P.; Guy, F.; Martin, D.; Baudouin, N.; Brunotte, F.; Dumas, R. [Centre Hospitalier Universitaire, 21 -Dijon (France)

    1996-06-01

    Aims: The aim of this work is to look for cerebral metabolic abnormalities within the first 3 days after a transient ischemic attack revealing an internal carotid stenosis > 70 %. Methods: Five patients with a transient ischemic attack lasting between 30 and 180 minutes, affecting sensory and motor brachio-facial territory, with or without aphasia. Were studied. A CT-scan, an EEG, a cervical Doppler ultrasound, a standard arteriography, a magnetic resonance imaging and a proton spectroscopy were performed within the cerebral area affected by the transient ischemic attack. We measured 2 markers: N-acetyl-aspartate, the marker of the neuronal mass, and lactate, the marker of anaerobe metabolism. In each case, a contralateral internal stenosis was diagnosed by cervical Doppler ultrasound and standard arteriography. No cerebral infarction was observed. Results: With the affected cerebral area defined according to clinical and EEG features, proton spectroscopy showed a significant rise of lactate, without any change in N-acetyl-aspartate levels. Conclusions: Within the first 3 days after a transient ischemic attack, there is a significant risk of lactate inside the affected cerebral area. This change may reflect a localized and transient hypoperfusion, but long enough to induce a rise of lactate but not sufficient to produce a cerebral infarct. This area is probably at risk to induce cerebral infarct. This data lead us to study the metabolic change induced by the asymptomatic internal carotid stenosis. (authors). 18 refs.

  14. Study on water leak-tightness of small leaks on a 1 inch cylinder valve

    International Nuclear Information System (INIS)

    Miyazawa, T.; Kasai, Y.; Inabe, N.; Aritomi, M.

    2002-01-01

    Practical thresholds for water leak-tightness of small leaks were determined by experimentation. Measurements for small leak samples were taken of air leakage rates and water leakage rates for identical leak samples in order to identify parameters that influence water leak-tightness threshold. Four types of leaks were evaluated: a fine wire inserted in an O-ring seal, a glass capillary tube, a stainless steel orifice, and a scratched valve stem on a 1 inch UF 6 cylinder valve. Experimental results demonstrated that the key parameter for water leak-tightness is the opening size of the leak hole. The maximum allowable hole size to achieve water leak-tightness ranged from 10 to 20 μm in diameter in this study. Experimental results with 1 inch UF 6 cylinder valve samples demonstrated that the acceptance criteria for preshipment leakage test, 1x10 -3 ref-cm 3 .s -1 , as prescribed in ANSI N14.5 is an appropriate value from the point of view of water leak-tightness for enriched UF 6 packages. The mechanism of water leak-tightness is plugging by tiny particles existing in water. The water used in experiments in this study contained far fewer particles than in water assumed to be encountered under accident conditions of transport. Therefore, the water leak-tightness threshold determined in this study is a conservative value in a practical evaluation. (author)

  15. He leaks in the CERN LHC beam vacuum chambers operating at cryogenic temperatures

    CERN Document Server

    Baglin, V

    2007-01-01

    The 27 km long large hadron collider (LHC), currently under construction at CERN, will collide protons beam at 14 TeV in the centre of mass. In the 8 arcs, the superconducting dipoles and quadrupoles of the FODO cells operate with superfluid He at 1.9 K. In the 8 long straight sections, the cold bores of the superconducting magnets are held at 1.9 or 4.5 K. Thus, in the LHC, 75% of the beam tube vacuum chamber is cooled with He. In many areas of the machine, He leaks could appear in the beam tube. At cryogenic temperature, the gas condenses onto the cold bores or beam screens, and interacts with the circulating beam. He leaks creates a He front propagating along the vacuum chambers, which might cause magnet quench. We discuss the consequences of He leaks, the possible means of detections, the strategies to localise them and the methods to measure their size.

  16. Summary of PWR leak detection studies

    International Nuclear Information System (INIS)

    Cho, J.H.; Elia, F.A. Jr.

    1986-01-01

    Thermal-hydraulic analysis can be used to determine the location and magnitude of leaks inside and location of leaks outside a pressurized water reactor (PWR) containment as required by plant technical specifications. The major advantage of this detection method is that it minimizes radiation exposure of maintenance personnel because most of the leak detection process is performed from the control room outside containment. Plant-specific analyses are utilized to predict change in parameters such as local dew point temperature, relative humidity, dry bulb temperature, and flow rate to sump for various leak rates and enthalpies. These parameter responses are then programmed into the plant computer and instrumentation is provided for area monitoring. The actual inputs are continuously monitored and compared to the predicted plant responses to identify the leak location and quantify the leak. This study concludes that a system that monitors dew point (or relative humidity) and dry bulb temperature changes together with the flow rate to the sump will provide the capability to both locate and quantify a leak inside a containment, while a system that monitors dew point temperature (or relative humidity) changes will provide the capability to locate a leak outside a containment

  17. ISOLDE Off-line Gas Leak Upgrade

    CERN Document Server

    Nielsen, Kristoffer Bested

    2017-01-01

    This study investigates gas injection system of the ISOLDE Off-line separator. A quadrupole mass spectrometer is used to analysis the composition of the gas. Based on these measurements a contamination of the injected gas is found and a system upgrade is purposed. Furthermore a calibration of the leak rate of the leak valve is made.

  18. Leak testing requirements at a research facility

    International Nuclear Information System (INIS)

    Conner, J.B.

    1979-01-01

    Since September, 1952, Lawrence Livermore Laboratory has conducted pioneering research in applied science. A vital part of this activity has been the development of a variety of high vacuum and ultrahigh vacuum systems. Leaks occur in everything, including vacuum systems. The mass spectrometer leak detection equipment is described

  19. Improved method of measurement for outer leak

    International Nuclear Information System (INIS)

    Xu Guang

    2012-01-01

    Pneumatic pipeline is installed for the airborne radioactivity measurement equipment, air tightness and outer leak rate are essential for the testing of the characteristics, both in the national criteria and ISO standards, an improved practical method is available for the measurement of the outer air leak rate based on the engineering experiences for the equipment acceptance and testing procedure. (authors)

  20. Capacitive system detects and locates fluid leaks

    Science.gov (United States)

    1966-01-01

    Electronic monitoring system automatically detects and locates minute leaks in seams of large fluid storage tanks and pipelines covered with thermal insulation. The system uses a capacitive tape-sensing element that is adhesively bonded over seams where fluid leaks are likely to occur.

  1. Leak detector of liquid sodium

    International Nuclear Information System (INIS)

    Himeno, Yoshiaki.

    1975-01-01

    Object: To arrange a cable core connected to a leakage current detector on the outer wall of piping for liquid sodium, devices or the like and apply a voltage to said core and outer wall to quickly and securely detect the leakage of liquid sodium. Structure: A cable, which is composed of metal coating formed of metal material (copper, steel, stainless, etc.) which is apt to be corroded by reaction products of liquid sodium with water and oxygen in air, and metal oxide (such as magnesium oxide, beryllium oxide, aluminum oxide) as an electric insulator is arranged on the outer wall of pipes or devices. In the event sodium is leaked from the pipes or devices, said metal coating and the insulator are corroded, and the leakage of sodium is sensed by a leakage current detector through the core in the cable. (Kamimura, M.)

  2. On the helium gas leak test

    International Nuclear Information System (INIS)

    Nishikawa, Akira; Ozaki, Susumu

    1975-01-01

    The helium gas leak test (Helium mass spectrometer testing) has a leak detection capacity of the highest level in practical leak tests and is going to be widely applied to high pressure vessels, atomic and vacuum equipments that require high tightness. To establish a standard test procedure several series of experiments were conducted and the results were investigated. The conclusions are summarized as follows: (1) The hood method is quantitatively the most reliable method. The leak rate obtained by tests using 100% helium concentration should be the basis of the other method of test. (2) The integrating method, bell jar method, and vacuum spray method can be considered quantitative when particular conditions are satisfied. (3) The sniffer method is not to be considered quantitive. (4) The leak rate of the hood, integrating, and bell jar methods is approximately proportional to the square of the helium partial pressure. (auth.)

  3. SCTI chemical leak detection test plan

    International Nuclear Information System (INIS)

    1981-01-01

    Tests will be conducted on the CRBRP prototype steam generator at SCTI to determine the effects of steam generator geometry on the response of the CRBRP chemical leak detection system to small water-to-sodium leaks in various regions of the steam generator. Specifically, small injections of hydrogen gas (simulating water leaks) will be made near the two tubesheets, and the effective transport times to the main stream exit and vent line hydrogen meters will be measured. The magnitude and time characteristics of the meters' response will also be measured. This information will be used by the Small Leak Protection Base Program (SG027) for improved predictions of meter response times and leak detection sensitivity

  4. Small sodium-to-gas leak behavior in relation to LMFBR leak detection system design

    International Nuclear Information System (INIS)

    Hopenfeld, J.; Taylor, G.R.; James, L.A.

    1976-01-01

    Various aspects of sodium-to-gas leaks which must be considered in the design of leak detection systems for LMFBR's are discussed. Attention is focused primarily on small, weeping type leaks. Corrosion rates of steels in fused sodium hydroxide and corrosion damage observed at the site of small leaks lead to the conclusion that the sodium-gas reaction products could attack the primary hot leg piping at rates up to 0.08 mils per hour. Based on theoretical considerations of the corrosion mechanism and on visual observations of pipe topography following small sodium leak tests, it is concluded that pipe damage will be manifested by the formation of small detectable leaks prior to the appearance of larger leaks. The case for uniform pipe corrosion along the pipe circumference or along a vertical section of the pipe is also examined. Using a theoretical model for the gravity flow of sodium and reaction products along the pipe surface and a mass transport controlled corrosion process, it is shown that below sodium leak rates of about 30 g/hr for the primary piping corrosion damage will not extend beyond one radius distance from the leak site. A method of estimating the time delay between the initiation of such leaks and the development of a larger leak due to increased pipe stresses resulting from corrosion is presented

  5. Leak Signature Space: An Original Representation for Robust Leak Location in Water Distribution Networks

    Directory of Open Access Journals (Sweden)

    Myrna V. Casillas

    2015-03-01

    Full Text Available In this paper, an original model-based scheme for leak location using pressure sensors in water distribution networks is introduced. The proposed approach is based on a new representation called the Leak Signature Space (LSS that associates a specific signature to each leak location being minimally affected by leak magnitude. The LSS considers a linear model approximation of the relation between pressure residuals and leaks that is projected onto a selected hyperplane. This new approach allows to infer the location of a given leak by comparing the position of its signature with other leak signatures. Moreover, two ways of improving the method’s robustness are proposed. First, by associating a domain of influence to each signature and second, through a time horizon analysis. The efficiency of the method is highlighted by means of a real network using several scenarios involving different number of sensors and considering the presence of noise in the measurements.

  6. A mathematical model for leak location and leak area determination in pipeline networks

    Directory of Open Access Journals (Sweden)

    Oyedokun O.I.

    2013-01-01

    Full Text Available Prompt leak location and leak area determination in oil and gas pipeline installations is an indispensable approach to controlling petroleum products wastages in pipes. However, there is an evident lack of literature information on this subject. In this paper, we modelled leak location detection and leak area determination in pipes by applying two methodologies and gave an illustrative example using simulated data with the aid of Matlab. A comparison of these two approaches resulted in an error of 6.24%, suggesting that the closer the leak is to the measurement station, the lower will be the time interval between two successive waves that will pass through the leak and get to the measurement station. The relationship between the pipe area and coefficient of reflection is parabolic. This contribution is valuable to pipeline engineers in the economic control of leaks.

  7. Ultrasonic Detectors Safely Identify Dangerous, Costly Leaks

    Science.gov (United States)

    2013-01-01

    In 1990, NASA grounded its space shuttle fleet. The reason: leaks detected in the hydrogen fuel systems of the Space Shuttles Atlantis and Columbia. Unless the sources of the leaks could be identified and fixed, the shuttles would not be safe to fly. To help locate the existing leaks and check for others, Kennedy Space Center engineers used portable ultrasonic detectors to scan the fuel systems. As a gas or liquid escapes from a leak, the resulting turbulence creates ultrasonic noise, explains Gary Mohr, president of Elmsford, New York-based UE Systems Inc., a long-time leader in ultrasonic detector technologies. "In lay terms, the leak is like a dog whistle, and the detector is like the dog ear." Because the ultrasound emissions from a leak are highly localized, they can be used not only to identify the presence of a leak but also to help pinpoint a leak s location. The NASA engineers employed UE s detectors to examine the shuttle fuel tanks and solid rocket boosters, but encountered difficulty with the devices limited range-certain areas of the shuttle proved difficult or unsafe to scan up close. To remedy the problem, the engineers created a long-range attachment for the detectors, similar to "a zoom lens on a camera," Mohr says. "If you are on the ground, and the leak is 50 feet away, the detector would now give you the same impression as if you were only 25 feet away." The enhancement also had the effect of reducing background noise, allowing for a clearer, more precise detection of a leak s location.

  8. Design of sealing arrangements for development of leak tight articulated manipulator for waste management and reprocessing plants

    International Nuclear Information System (INIS)

    Patil, Satish B.; Mudaiya, Avinash K.

    2016-01-01

    As a part of development of Remote handling equipment and gadgets, Leak tight Articulated Manipulator (ARTM) has been developed for shielded facilities of Nuclear Recycle Plant. The ARTM is a Master Slave Manipulator having 8 Kg Payload capacity and most suitable for shielded sampling cubicles of Waste Management plants and dilution hot cells of Reprocessing plants. All the motions and forces are transmitted from Master to slave arm through the mechanical linkages, which are housed inside the wall tube. The mechanical linkages and wall tube run across the shielded wall. The applications involving seal tightness of the glove boxes and dilution hot cells intend to use all the accessories including MSMs to be leak tight. During the design of leak tight ARTM, all the potential leak paths through the components of existing ARTM were examined critically and static and dynamic seals were designed based on the geometry and requirement of particular leak path. A leak proof testing set up was fabricated for evaluating the leak rates across the manipulator contemplating the actual operating conditions. The manipulator was subjected to the Friction, Rigidity and Leak tests. The results of the tests are satisfactory and as per the International standards available. The leak rates measured for different manipulators were in the range of 0.05 to 0.1 % of air volume/hr @ 200 mm of water columndifferential negative pressure. (author)

  9. Orai3 channel is the 2-APB-induced endoplasmic reticulum calcium leak.

    Science.gov (United States)

    Leon-Aparicio, Daniel; Pacheco, Jonathan; Chavez-Reyes, Jesus; Galindo, Jose M; Valdes, Jesus; Vaca, Luis; Guerrero-Hernandez, Agustin

    2017-07-01

    We have studied in HeLa cells the molecular nature of the 2-APB induced ER Ca 2+ leak using synthetic Ca 2+ indicators that report changes in both the cytoplasmic ([Ca 2+ ] i ) and the luminal ER ([Ca 2+ ] ER ) Ca 2+ concentrations. We have tested the hypothesis that Orai channels participate in the 2-APB-induced ER Ca 2+ leak that was characterized in the companion paper. The expression of the dominant negative Orai1 E106A mutant, which has been reported to block the activity of all three types of Orai channels, inhibited the effect of 2-APB on the [Ca 2+ ] ER but did not decrease the ER Ca 2+ leak after thapsigargin (TG). Orai3 channel, but neither Orai1 nor Orai2, colocalizes with expressed IP 3 R and only Orai3 channel supported the 2-APB-induced ER Ca 2+ leak, while Orai1 and Orai2 inhibited this type of ER Ca 2+ leak. Decreasing the expression of Orai3 inhibited the 2-APB-induced ER Ca 2+ leak but did not modify the ER Ca 2+ leak revealed by inhibition of SERCA pumps with TG. However, reducing the expression of Orai3 channel resulted in larger [Ca 2+ ] i response after TG but only when the ER store had been overloaded with Ca 2+ by eliminating the acidic internal Ca 2+ store with bafilomycin. These data suggest that Orai3 channel does not participate in the TG-revealed ER Ca 2+ leak but forms an ER Ca 2+ leak channel that is limiting the overloading with Ca 2+ of the ER store. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Lifetime of the internal reference oxygen sensor

    DEFF Research Database (Denmark)

    Hu, Qiang; Jacobsen, Torben; Hansen, Karin Vels

    2013-01-01

    The internal reference oxygen sensor (IROS) based on a binary mixture of metal and its stoichiometric oxide is subject to leaks that result in consumption of the binary mixture. An IROS loses the functionality when the binary mixture is exhausted. Among the possible leak sources the electronic leak...

  11. Imaging review of cerebrospinal fluid leaks.

    Science.gov (United States)

    Vemuri, Naga V; Karanam, Lakshmi S P; Manchikanti, Venkatesh; Dandamudi, Srinivas; Puvvada, Sampath K; Vemuri, Vineet K

    2017-01-01

    Cerebrospinal fluid (CSF) leak occurs due to a defect in the dura and skull base. Trauma remains the most common cause of CSF leak; however, a significant number of cases are iatrogenic, and result from a complication of functional endoscopic sinus surgery (FESS). Early diagnosis of CSF leak is of paramount importance to prevent life-threatening complications such as brain abscess and meningitis. Imaging plays a crucial role in the detection and characterization of CSF leaks. Three-dimensional, isotropic, high resolution computed tomography (HRCT) accurately detects the site and size of the bony defect. CT cisternography, though invasive, helps accurately identify the site of CSF leak, especially in the presence of multiple bony defects. Magnetic resonance imaging (MRI) accurately detects CSF leaks and associated complications such as the encephaloceles and meningoceles. In this review, we emphasize the importance and usefulness of 3D T2 DRIVE MR cisternography in localizing CSF leaks. This sequence has the advantages of effective bone and fat suppression, decreased artefacts, faster acquisition times, three-dimensional capability, y and high spatial resolution in addition to providing very bright signal from the CSF.

  12. Imaging review of cerebrospinal fluid leaks

    Directory of Open Access Journals (Sweden)

    Naga V Vemuri

    2017-01-01

    Full Text Available Cerebrospinal fluid (CSF leak occurs due to a defect in the dura and skull base. Trauma remains the most common cause of CSF leak; however, a significant number of cases are iatrogenic, and result from a complication of functional endoscopic sinus surgery (FESS. Early diagnosis of CSF leak is of paramount importance to prevent life-threatening complications such as brain abscess and meningitis. Imaging plays a crucial role in the detection and characterization of CSF leaks. Three-dimensional, isotropic, high resolution computed tomography (HRCT accurately detects the site and size of the bony defect. CT cisternography, though invasive, helps accurately identify the site of CSF leak, especially in the presence of multiple bony defects. Magnetic resonance imaging (MRI accurately detects CSF leaks and associated complications such as the encephaloceles and meningoceles. In this review, we emphasize the importance and usefulness of 3D T2 DRIVE MR cisternography in localizing CSF leaks. This sequence has the advantages of effective bone and fat suppression, decreased artefacts, faster acquisition times, three-dimensional capability, y and high spatial resolution in addition to providing very bright signal from the CSF.

  13. Successful Endoscopic Therapy of Traumatic Bile Leaks

    Directory of Open Access Journals (Sweden)

    Matthew P. Spinn

    2013-02-01

    Full Text Available Traumatic bile leaks often result in high morbidity and prolonged hospital stay that requires multimodality management. Data on endoscopic management of traumatic bile leaks are scarce. Our study objective was to evaluate the efficacy of the endoscopic management of a traumatic bile leak. We performed a retrospective case review of patients who were referred for endoscopic retrograde cholangiopancreatography (ERCP after traumatic bile duct injury secondary to blunt (motor vehicle accident or penetrating (gunshot trauma for management of bile leaks at our tertiary academic referral center. Fourteen patients underwent ERCP for the management of a traumatic bile leak over a 5-year period. The etiology included blunt trauma from motor vehicle accident in 8 patients, motorcycle accident in 3 patients and penetrating injury from a gunshot wound in 3 patients. Liver injuries were grade III in 1 patient, grade IV in 10 patients, and grade V in 3 patients. All patients were treated by biliary stent placement, and the outcome was successful in 14 of 14 cases (100%. The mean duration of follow-up was 85.6 days (range 54-175 days. There were no ERCP-related complications. In our case review, endoscopic management with endobiliary stent placement was found to be successful and resulted in resolution of the bile leak in all 14 patients. Based on our study results, ERCP should be considered as first-line therapy in the management of traumatic bile leaks.

  14. Pipeline leak detection using volatile tracers

    International Nuclear Information System (INIS)

    Thompson, G.M.; Golding, R.D.

    1993-01-01

    A method of leak detection for underground storage tanks and pipelines adds volatile tracers to the products in the tanks and analyzes the surrounding shallow soil gases for tracer vapors. This method has several advantages: the success of the test is not limited by the size and structural design of the vessels, tanks can be tested at any fill level without taking the tank out of service, the location of a leak along a pipeline is clearly marked by the location of the tracer, and liquid leaks as small as 0.2 liters per hour (lph) can be detected. A limitation is: the backfill material must have some degree of air permeability in the zone above the water table. Several field tests document the success achieved using this method. A tracer leak detection system was installed at Homestead AFB after several other testing methods failed to locate a leak at a valve pit location along approximately 4 kilometers of fuel transfer piping. The leak was detected to the side of the valve pit at a depth of approximately 2.5 meters below the ground surface. Another installation of Edwards AFB involved the collection of 415 soil gas samples along approximately 3,050 meters of 15.25-centimeter fiberglass pipeline. Fourteen separate leaks were detected

  15. Vacuum leak test technique of JT-60

    International Nuclear Information System (INIS)

    Kaminaga, Atsushi; Arai, Takashi; Kodama, Kozo; Sasaki, Noboru; Saidoh, Masahiro

    1998-01-01

    Since a vacuum vessel of JT-60 is very large (167 m 3 ) and is combined with many components, such as magnetic coils, neutral beam injection systems and RF heating systems, etc., the position of leak testing exceeds 700. The two kind of techniques for vacuum leak test used in JT-60 has been described. Firstly the probe helium gas can be fed remotely in the three-dimensionally sectioned 54 regions of the JT-60 torus. The leak test was very rapidly performed by using this method. Secondly the helium detector system has been modified by the additional installation of the cryopump, which reduced the background level of the deuterium gas. The sensitivity of vacuum leak test with the cryopump was two orders of magnitude larger than that of without it. The examples of the performed vacuum leak test are stated. The vacuum leaks during experiments were 9 times. They were caused by thermal strain and plasma discharge. The vacuum leaks just after maintenance are 36 times which mainly caused by mis-installation. (author)

  16. PROTON MICROSCOPY AT FAIR

    International Nuclear Information System (INIS)

    Merrill, F. E.; Mariam, F. G.; Golubev, A. A.; Turtikov, V. I.; Varentsov, D.

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and a facility has been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international effort has investigated a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located in Darmstadt, Germany. This new Proton microscope for FAIR(PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. It is also proposed to install the PRIOR system at the GSI Helmholtzzentrum fuer Schwerionenforschung before installation at FAIR for dynamic experiments with different drivers including high explosives, pulsed power and lasers. The design of the proton microscope and expected radiographic performance is presented.

  17. 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.

  18. Leak detection system for RBMK coolant circuit

    International Nuclear Information System (INIS)

    Cherkashov, Ju.M.; Strelkov, B.P.; Korolev, Yu.V.; Eperin, A.P.; Kozlov, E.P.; Belyanin, L.A.; Vanukov, V.N.

    1996-01-01

    In report the description of an object of the control is submitted, requests to control of leak-tightness and functioning of system are formulated, analysis of a current status on NPP with RBMK is submitted, review of methods of the leak-tightness monitoring, their advantage and defects with reference to conditions and features of a design RBMK is indicated, some results of tests and operation of various monitoring methods are submitted, requests on interaction of operative staff, leak-tightness monitoring system and protection system of reactor are submitted. (author). 11 figs, 1 tab

  19. Acoustic leak detector in Monju steam generator

    International Nuclear Information System (INIS)

    Wachi, E.; Inoue, T.

    1990-01-01

    Acoustic leak detectors are equipped with the Monju steam generators for one of the R and D activities, which are the same type of the detectors developed in the PNC 50MW Steam Generator Test Facility. Although they are an additional leak detection system to the regular one in Monju SG, they would also detect the intermediate or large leaks of the SG tube failures. The extrapolation method of a background noise analysis is expected to be verified by Monju SG data. (author). 4 figs

  20. Means for preventing radioactive fluid leaking

    International Nuclear Information System (INIS)

    Akatsu, Jun-ichi.

    1975-01-01

    Object: To permit prevention of leakage of radioactive fluid from line and valve leak sections while also recovering the liquid by producing a vacuum state in a leak-off line by means of a water ejector. Structure: A portion of the water from a condenser is forced by a condensed water pump through a water ejector tank to a recovery tank while controlling an orifice and valve, whereby a vacuum state is produced in the leak-off line to withdraw the leakage fluid. (Kamimura, M.)

  1. Leak detection system for RBMK coolant circuit

    Energy Technology Data Exchange (ETDEWEB)

    Cherkashov, Ju M; Strelkov, B P; Korolev, Yu V; Eperin, A P; Kozlov, E P; Belyanin, L A; Vanukov, V N [Leningrad Nuclear Power Plant, Leningrad (Russian Federation). Research and Development Inst. of Power Engineering

    1997-12-31

    In report the description of an object of the control is submitted, requests to control of leak-tightness and functioning of system are formulated, analysis of a current status on NPP with RBMK is submitted, review of methods of the leak-tightness monitoring, their advantage and defects with reference to conditions and features of a design RBMK is indicated, some results of tests and operation of various monitoring methods are submitted, requests on interaction of operative staff, leak-tightness monitoring system and protection system of reactor are submitted. (author). 11 figs, 1 tab.

  2. Protonic decay of oriented nuclei

    International Nuclear Information System (INIS)

    Kadmensky, S.G.

    2002-01-01

    On the basis of the multiparticle theory of protonic decay, the angular distributions of protons emitted by oriented spherical and deformed nuclei in the laboratory frame and in the internal coordinate frame of deformed parent nuclei are constructed with allowance for symmetry with respect to time inversion. It is shown that, because of the deep-subbarrier character of protonic decay, the adiabatic approximation is not applicable to describing the angular distributions of protons emitted by oriented deformed nuclei and that the angular distribution of protons in the laboratory frame does not coincide with that in the internal coordinate frame. It is demonstrated that these angular distributions coincide only if the adiabatic and the semiclassical approximation are simultaneously valid

  3. Evaluación del uso de los inhibidores de la bomba de protones en un servicio de medicina interna Assessing the use of proton pump inhibitors in an internal medicine department

    Directory of Open Access Journals (Sweden)

    E. Martín-Echevarría

    2008-02-01

    Full Text Available Introducción: los inhibidores de la bomba de protones (IBP bloquean la enzima H+/K+ ATPasa en las células parietales gástricas, logrando la inhibición de la secreción de ácido clorhídrico de forma basal como tras estimulación. Las indicaciones apropiadas para su uso son: enfermedad por reflujo gastroesofágico, hemorragia digestiva aguda, úlceras activas, gastritis o esofagitis erosiva, dispepsia, gastropatía por AINE, profilaxis de úlcera de estrés en pacientes de riesgo. El objetivo del estudio fue la revisión de las indicaciones de los IBP en nuestro medio y la evaluación de su utilización en el Hospital Universitario de Guadalajara. Material y métodos: se realizó un estudio de corte transversal analítico con selección aleatoria de los pacientes atendidos en el Servicio de Medicina Interna durante todo el año 2003. Se revisaron un total de 208 historias de 832 pacientes (un 25% a los que se administraron IBP. La edad media fue de 67 años (rango 16-92, el 46,2% fueron mujeres y las enfermedades subyacentes más frecuentes fueron: HTA, EPOC y DM. Resultados: un 34,6% de los pacientes tomaban IBP antes del ingreso. De estos, el 68,1% no tenía indicación. Durante el ingreso se prescribió de forma inadecuada el IBP al 73,07% y al alta, se mantenía el IBP sin indicación correcta. Conclusiones: los resultados están en concordancia con los anteriormente publicados, manteniéndose una alta frecuencia de uso incorrecto de los IBP y siendo recomendable una utilización más racional para evitar los efectos secundarios, las interacciones con otros fármacos y aportar una atención médica más eficiente.Introduction: proton pump inhibitors (PPIs block the H+/K+ ATPase enzyme in gastric wall cells, leading to an inhibition of both baseline and stimulated acid secretion. Appropriate indications include: Gastroesophageal reflux, acute upper gastrointestinal bleeding, erosive gastritis or esophagitis, dyspepsia, NSAID

  4. The leak microstructure, preliminary results

    International Nuclear Information System (INIS)

    Lombardi, M.

    1997-01-01

    The leak microstructure, a new type of element for position-sensitive proportional gas counter, is introduced. For every single detected ionizing radiation it gives a pair of ''induced'' charges of the same quantity (pulses of the same amplitude), of opposite sign, with the same collection time and essentially in time coincidence, that are proportional to the collected primary ionization. A gas multiplication up to 1.5 x 10 5 was achieved. The complete absence of insulating materials in the active volume of this microstructure enables to avoid problems of charging-up and makes its behaviour stable and repeatable. By using the charge-pair generated, it allows the development of a position-sensitive detecting board with a two-dimensional read-out. Between the two external surfaces of this board it is possible to insert an intermediate third conducting layer which reduces (or practically suppresses) the capacitive cross-talk between the X and Y read-out strip systems. Furthermore, this intermediate layer can give a very fast trigger to coordinate the charge-pair and to govern the data acquisition system. By reading every strip separately it is possible to resolve the multi hit problem in two-dimensions. Using isobutane as the gas, an energy resolution of about 8% FWHM was recorded with α-particles from an 241 Am source. In isobutane gas, X-rays from a 55 Fe source and β-particles from a 14 C source were also detected. (orig.)

  5. Do protons decay

    International Nuclear Information System (INIS)

    Litchfield, P.J.

    1984-09-01

    The experimental status of proton decay is reviewed after the Leipzig International conference, July 1984. A brief comparative description of the currently active experiments is given. From the overall samples of contained events it can be concluded that the experiments are working well and broadly agree with each other. The candidates for proton decay from each experiment are examined. Although several experiments report candidates at a higher rate than expected from background calculations, the validity of these calculations is still open to doubt. (author)

  6. Endoscopic management of bile leaks after laparoscopic ...

    African Journals Online (AJOL)

    Endoscopic management of bile leaks after laparoscopic cholecystectomy. ... endoscopic management at a median of 12 days (range 2 - 104 days) after surgery. Presenting features included intra-abdominal collections with pain in 58 cases ...

  7. Evaluation of leak rate by EPRI code

    International Nuclear Information System (INIS)

    Isozaki, Toshikuni; Hashiguchi, Issei; Kato, Kiyoshi; Miyazono, Shohachiro

    1987-08-01

    From 1987, a research on the leak rate from a cracked pipe under BWR or PWR operating condition is going to be carried out at the authors' laboratory. This report describes the computed results by EPRI's leak rate code which was mounted on JAERI FACOM-M380 machine. Henry's critical flow model is used in this program. For the planning of an experimental research, the leak rate from a crack under BWR or PWR operating condition is computed, varying a crack length 2c, crack opening diameter COD and pipe diameter. The COD value under which the minimum detectable leak rate of 5 gpm is given is 0.22 mm or 0.21 mm under the BWR or PWR condition with 2c = 100 mm and 16B pipe geometry. The entire lists are shown in the appendix. (author)

  8. The new CSA standard for leak detection

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Ulli [TAU, Edmonton, Alberta, (Canada); Scott, Don [TransCanada Pipelines, Edmonton, Alberta, (Canada)

    2010-07-01

    Standards need to be updated regularly to reflect current technology and industry practices. This paper describes the new Canadian Standards Association (CSA) for leak detection called Recommended Practice for Liquid Hydrocarbon Pipeline System Leak Detection, Annex E, which can be found in the CSA Z662 Oil and Gas Pipeline Systems standard. The CSA formed a task force of industry experts and regulators for a period of 18 months to draft the new standards. Several comparisons were made with the American Petroleum Institute (API) recommended practice API 1130. This new version introduces and defines the terms, critical instrument, critical process and dependent instrument. The most significant improvement made by the new Annex E is the new requirement that an operating company must develop a leak detection strategy. The writing of a leak detection manual is given high priority. The use of both Annex E and API 1130 is recommended.

  9. Postoperative ascitic leaks: the ongoing challenge.

    Science.gov (United States)

    Rosemurgy, A S; Statman, R C; Murphy, C G; Albrink, M H; McAllister, E W

    1992-06-01

    The leak of ascitic fluid from surgical incisions is thought to be associated with a very high mortality rate. There have been few reports, however, focusing on the clinical characteristics, management, or mortality rates of this condition. During a 10-year period, 18 patients with postoperative ascitic fluid leaks were treated. All patients had ascites before surgery and all had liver disease; in 13 of the 18 patients alcoholic liver disease was the cause of ascites. Ten of the 18 patients died (56%). Midline incisions were more often associated with recalcitrant leaks and fatal complications than were transverse incisions. Early consideration of fascial dehiscence and prompt repair is emphasized. The most effective predictor of survival was cessation of the leak.

  10. Helium leak testing the Westinghouse LCP coil

    International Nuclear Information System (INIS)

    Merritt, P.A.; Attaar, M.H.; Hordubay, T.D.

    1983-01-01

    The tests, equipment, and techniques used to check the Westinghouse LCP coil for coolant flow path integrity and helium leakage are unique in terms of test sensitivity and application. This paper will discuss the various types of helium leak testing done on the LCP coil as it enters different stages of manufacture. The emphasis will be on the degree of test sensitivity achieved under shop conditions, and what equipment, techniques and tooling are required to achieve this sensitivity (5.9 x 10 -8 scc/sec). Other topics that will be discussed are helium flow and pressure drop testing which is used to detect any restrictions in the flow paths, and the LCP final acceptance test which is the final leak test performed on the coil prior to its being sent for testing. The overall allowable leak rate for this coil is 5 x 10 -6 scc/sec. A general evaluation of helium leak testing experience are included

  11. Leak Detectives Saving Money, Water in Virginia

    Science.gov (United States)

    “Circuit riders” from the Virginia Rural Water Association (VRWA) are traveling to small communities across the Commonwealth using special equipment financed by EPA to locate expensive and wasteful leaks in drinking water distribution systems.

  12. Acoustic leak detection in piping systems, 4

    International Nuclear Information System (INIS)

    Kitajima, Akira; Naohara, Nobuyuki; Aihara, Akihiko

    1983-01-01

    To monitor a high-pressure piping of nuclear power plants, a possibility of acoustic leak detection method has been experimentally studied in practical field tests and laboratory tests. Characteristics of background noise in field test and the results of experiment are summarized as follows: (1) The level of background noise in primary loop (PWR) was almost constant under actual plant operation. But it is possible that it rises at the condition of the pressure in primary loop. (2) Based on many experience of laboratory tests and practical field tests. The leak monitoring system for practical field was designed and developed. To improve the reliability, a judgment of leak on this system is used three factors of noise level, duration time of phenomena and frequency spectrum of noise signal emitted from the leak point. (author)

  13. Acoustic leak detection in nuclear power plants

    International Nuclear Information System (INIS)

    McElroy, J.W.

    1986-01-01

    For several years now, utilities have been utilizing acoustic leak detection methods as an operating tool in their nuclear power stations. The purpose for using the leak detection system at the various stations vary from safety, ALARA, improved operations, preventive maintenance, or increased plant availability. This paper describes the various acoustic techniques and their application. The techniques are divided into three categories: specific component leakage, intersystem leakage, and pipe through-wall crack leakage. The paper addresses each category in terms of motivation to monitor, method of application and operation, and benefits to be gained. Current requirements are reviewed and analyzed with respect to the acoustic techniques. The paper shows how acoustic leak detection is one of the most effective leak detection tools available. 9 figures, 1 table

  14. Leaking Underground Storage Tank Sites in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Leaking Underground Storage Tank (LUST) sites where petroleum contamination has been found. There may be more than one LUST site per UST site.

  15. Routine intraoperative leak testing for sleeve gastrectomy: is the leak test full of hot air?

    Science.gov (United States)

    Bingham, Jason; Lallemand, Michael; Barron, Morgan; Kuckelman, John; Carter, Preston; Blair, Kelly; Martin, Matthew

    2016-05-01

    Staple line leak after sleeve gastrectomy (SG) is a rare but dreaded complication with a reported incidence of 0% to 8%. Many surgeons routinely test the staple line with an intraoperative leak test (IOLT), but there is little evidence to validate this practice. In fact, there is a theoretical concern that the leak test may weaken the staple line and increase the risk of a postop leak. Retrospective review of all SGs performed over a 7-year period was conducted. Cases were grouped by whether an IOLT was performed, and compared for the incidence of postop staple line leaks. The ability of the IOLT for identifying a staple line defect and for predicting a postoperative leak was analyzed. Five hundred forty-two SGs were performed between 2007 and 2014. Thirteen patients (2.4%) developed a postop staple line leak. The majority of patients (n = 494, 91%) received an IOLT, including all 13 patients (100%) who developed a subsequent clinical leak. There were no (0%) positive IOLTs and no additional interventions were performed based on the IOLT. The IOLT sensitivity and positive predictive value were both 0%. There was a trend, although not significant, to increase leak rates when a routine IOLT was performed vs no routine IOLT (2.6% vs 0%, P = .6). The performance of routine IOLT after SG provided no actionable information, and was negative in all patients who developed a postoperative leak. The routine use of an IOLT did not reduce the incidence of postop leak, and in fact was associated with a higher leak rate after SG. Published by Elsevier Inc.

  16. The effect of channel flow pattern on internal properties distribution of a proton exchange membrane fuel cell for cathode starvation conditions

    International Nuclear Information System (INIS)

    Ko, Dong Soo; Kang, Young Min; Yang, Jang Sik; Jeong, Ji Hwan; Choi, Gyung Min; Kim, Duck Jool

    2010-01-01

    The effect of channel flow pattern on the internal properties distribution of a proton exchange membrane fuel cell (PEMFC) for cathode starvation conditions in a unit cell was investigated through numerical studies and experiments. The polarization curves of a lab-scale mixed serpentine PEMFC were measured with increasing current loads for different cell temperatures (40, 50, and 60 .deg. C) at a relative humidity of 100%. To study the local temperature on the membrane, the water content in the MEA, and the gas velocity in terms of the channel type of the PEMFC with operating characteristics, numerical studies using the es-pemfc module of STAR-CD, which have been matched to the experimental data, were conducted in detail. The water content and velocity at the cathode channel bend of the mixed serpentine channel were relatively higher than those at the single and double channels. Conversely, the local temperature and mean temperature on the membrane of a single serpentine channel were the highest among all channels. These results can be used to design the PEMFC system, the channel flow field, and the cooling device

  17. Cable-Based Water Leak Detection Technology

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Water leaks can be considered as a serious problem from many sources such as water supply and return chains, air conditioning units, cold-water chillers, clogged drains, damaged skylights or windows, or even construction errors. The new water leak detection technologies can provide significant advantages in cost, reliability, and easy adoption have continued since the traditional technology mainly focusing on a spot detector revealed several limitations.

  18. Evaluation of pipeline leak detection systems

    International Nuclear Information System (INIS)

    Glauz, W.D.; Flora, J.D.; Hennon, G.J.

    1993-01-01

    Leaking underground storage tank system presents an environmental concern and a potential health hazard. It is well known that leaks in the piping associated with these systems account for a sizeable fraction of the leaks. EPA has established performance standards for pipeline leak detection systems, and published a document presenting test protocols for evaluating these systems against the standards. This paper discusses a number of facets and important features of evaluating such systems, and presents results from tests of several systems. The importance of temperature differences between the ground and the product in the line is shown both in theory and with test data. The impact of the amount of soil moisture present is addressed, along with the effect of frozen soil. These features are addressed both for line tightness test systems, which must detect leaks of 0.10 gal/h (0.38 L/h) at 150% of normal line pressure, or 0.20 gal/h (0.76 L/h) at normal line pressure, and for automatic line leak detectors that must detect leaks of 3 gal/h (11 L/h) at 10 psi (69 kPa) within an hour of the occurrence of the leak. This paper also addresses some statistical aspects of the evaluation of these systems. Reasons for keeping the evaluation process ''blind'' to the evaluated company are given, along with methods for assuring that the tests are blind. Most importantly, a test procedure is presented for evaluating systems that report a flow rate (not just a pass/fail decision) that is much more efficient than the procedure presented in the EPA protocol, and is just as stringent

  19. Detection of primary coolant leaks in NPP

    International Nuclear Information System (INIS)

    Slavov, S.; Bakalov, I.; Vassilev, H.

    2001-01-01

    The thermo-hydraulic analyses of the SG box behaviour of Kozloduy NPP units 3 and 4 in case of small primary circuit leaks and during normal operation of the existing ventilation systems in order to determine the detectable leakages from the primary circuit by analysing different parameters used for the purposes of 'Leak before break' concept, performed by ENPRO Consult Ltd. are presented. The following methods for leak detection: measurement of relative air humidity in SG box (can be used for detection of leaks with flow rate 3.78 l/min within one hour at ambient parameters - temperature 40 0 - 60 0 C and relative humidity form 30% to 60%); measurement of water level in SG box sumps (can not be used for reliable detection of small primary circuit leakages with flow rate about 3.78 l/min); measurement of gaseous radioactivity in SG box( can be used as a general global indication for detection of small leakages from the primary circuit); measurement of condensate flow after the air coolers of P-1 venting system (can be used for primary circuit leak detection) are considered. For determination of the confinement behaviour, a model used with computer code MELCOR has been developed by ENPRO Consult Ltd. A brief summary based on the capabilities of the different methods of leak detection, from the point of view of the applicability of a particular method is given. For both Units 3 and 4 of Kozloduy NPP a qualified complex system for small leak detection is planned to be constructed. Such a system has to unite the following systems: acoustic system for leak detection 'ALUS'; system for control of the tightness of the main primary circuit pipelines by monitoring the local humidity; system for primary circuit leakage detection by measuring condensate run-off in collecting tank after ventilation system P-1 air coolers

  20. Leak of draft report on radioactive waste

    International Nuclear Information System (INIS)

    1986-01-01

    The Environment Committee's second report discusses the leak of the draft report on radioactive waste. The circumstances of the leak are discussed and ''The Times'' and ''The Guardian'' articles of December 1985 are printed in full, as are the letter from the Chairman of the environmental committee to the members and their replies. The letters from Mr John Large of Large and Associates to the Chairman of the Environment Committee, and Mr Large's correspondence with Greenpeace are also printed. (UK)

  1. [Survey of the prescriptions of proton pump inhibitors in patients admitted in an internal medicine ward: how is the compliance to the French guidelines?].

    Science.gov (United States)

    Sauvaget, L; Rolland, L; Dabadie, S; Desblaches, J; Bernard, N; Vandenhende, M-A; Bonnet, F; Pédeboscq, S; Morlat, P

    2015-10-01

    In June 2009, the national French authority for Health reported many off-label uses of proton pump inhibitors (PPI). Our objective was to analyse the justification and modalities of PPI prescriptions in patients before their admission in a department of internal medicine. Data were prospectively collected during 5months. At admission, all prescriptions of PPI by general practitioners (GP) were recorded. The accordance of the prescriptions with the marketing authorization indications and the French guidelines in terms of duration of treatment or dosage was analyzed. These informations were obtained from computerized medical records and, if necessary, by contacting GPs. We collected 173 prescriptions. Fifty-six (32%) were in accordance with marketing authorization indications and, among them, 15 prescriptions (9% of all) respected the French guidelines about dosage and duration of treatment. One hundred and six prescriptions (61%) were not adequate and among them an off-label use was notified in 91 (53% of all); among them 33% for simple dyspeptic disorders, 23% for the prevention of NSAID-induced lesions in patients without risk factors, and finally 17% for the prevention of stress ulcer. Fifty-two prescriptions (30%) were unclassified due to incomplete data. Our study showed that a vast majority of the prescriptions for PPIs are not in accordance with French guidelines. Preventive actions against abusive prescriptions, withdrawal strategies or replacement of already prescribed PPIs should be implemented to reduce the risk of side effects and the economic impact of long term use of PPIs. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  2. Wireless sensor network for sodium leak detection

    International Nuclear Information System (INIS)

    Satya Murty, S.A.V.; Raj, Baldev; Sivalingam, Krishna M.; Ebenezer, Jemimah; Chandran, T.; Shanmugavel, M.; Rajan, K.K.

    2012-01-01

    Highlights: ► Early detection of sodium leak is mandatory in any reactor handling liquid sodium. ► Wireless sensor networking technology has been introduced for detecting sodium leak. ► We designed and developed a wireless sensor node in-house. ► We deployed a pilot wireless sensor network for handling nine sodium leak signals. - Abstract: To study the mechanical properties of Prototype Fast Breeder Reactor component materials under the influence of sodium, the IN Sodium Test (INSOT) facility has been erected and commissioned at Indira Gandhi Centre for Atomic Research. Sodium reacts violently with air/moisture leading to fire. Hence early detection of sodium leak if any is mandatory for such plants and almost 140 sodium leak detectors are placed throughout the loop. All these detectors are wired to the control room for data collection and monitoring. To reduce the cost, space and maintenance that are involved in cabling, the wireless sensor networking technology has been introduced in the sodium leak detection system of INSOT. This paper describes about the deployment details of the pilot wireless sensor network and the measures taken for the successful deployment.

  3. Helium leak testing of scanning electron microscope

    International Nuclear Information System (INIS)

    Ahmad, Anis; Tripathi, S.K.; Mukherjee, D.

    2015-01-01

    Scanning Electron Microscope (SEM) is a specialized electron-optical device which is used for imaging of miniscule features on topography of material specimens. Conventional SEMs used finely focused high energy (about 30 KeV) electron beam probes of diameter of about 10nm for imaging of solid conducting specimens. Vacuum of the order of 10"-"5 Torr is prerequisite for conventional Tungsten filament type SEMs. One such SEM was received from one of our laboratory in BARC with a major leak owing to persisting poor vacuum condition despite continuous pumping for several hours. He-Leak Detection of the SEM was carried out at AFD using vacuum spray Technique and various potential leak joints numbering more than fifty were helium leak tested. The major leak was detected in the TMP damper bellow. The part was later replaced and the repeat helium leak testing of the system was carried out using vacuum spray technique. The vacuum in SEM is achieved is better than 10"-"5 torr and system is now working satisfactorily. (author)

  4. Leak detector for reactor pressure vessel

    International Nuclear Information System (INIS)

    Morimoto, Mikio.

    1991-01-01

    A branched pipe is disposed to a leak off pipeline led from a flange surface which connects the main body and the upper lid of a reactor pressure vessel. An exhaust pump is disposed to the branched pipe and a moisture gage is disposed on the side of the exhaustion and a dry air supplier is connected to the branched pipe. Upon conducting a pressure-proof leak test for the reactor pressure vessel, the exhaust pump is operated and an electromagnet valve disposed at the upstream of the dry air supplier is opened and closed repeatedly. The humidity of air sucked by the exhaust pump is detected by the moisture gage. If leaks should be caused in the joining surface of the flange, leaked water is diffused as steams. Accordingly, occurrence of leak can be detected instantly based on the comparison with the moisture level of the dry air as a standard. In this way, a leak test can be conducted reliably in a short period of time with no change of for the reactor pressure container itself. (I.N.)

  5. 40 CFR 63.424 - Standards: Equipment leaks.

    Science.gov (United States)

    2010-07-01

    ....424 Standards: Equipment leaks. (a) Each owner or operator of a bulk gasoline terminal or pipeline... location of all equipment in gasoline service at the facility. (c) Each detection of a liquid or vapor leak... replacement of leaking equipment shall be completed within 15 calendar days after detection of each leak...

  6. Small leak shutdown, location, and behavior in LMFBR steam generators

    International Nuclear Information System (INIS)

    Sandusky, D.W.

    1976-01-01

    The paper summarizes an experimental study of small leaks tested under LMFBR steam generator conditions. Defected tubes were exposed to flowing sodium and steam. The observed behavior of the defected tubes is reported along with test results of shutdown methods. Leak location methods were investigated. Methods were identified to open plugged defects for helium leak testing and detect plugged leaks by nondestructive testing

  7. 40 CFR 86.328-79 - Leak checks.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Leak checks. 86.328-79 Section 86.328... Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.328-79 Leak checks. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could...

  8. Development of a portable heavy-water leak sensor based on laser absorption spectroscopy

    International Nuclear Information System (INIS)

    Lee, Lim; Park, Hyunmin; Kim, Taek-Soo; Kim, Minho; Jeong, Do-Young

    2016-01-01

    Highlights: • We developed a compact and portable laser sensor for a detection of heavy water leakage. • The sensor is wearable and also easy to use to search for the leak point. • It is sensitive enough to find invisible very tiny leaks. - Abstract: A compact and portable leak sensor based on cavity enhanced absorption spectroscopy has been newly developed for a detection of heavy water leakage which may happen in the facilities using heavy water such as pressurized heavy water reactor (PHWR). The developed portable sensor is suitable as an individual instrument for the measuring leak rate and finding the leak location because it is sufficiently compact in size and weight and operated by using an internal battery. In the performance test, the minimum detectable leak rate was estimated as 0.05 g/day from the calibration curve. This new sensor is expected to be a reliable and promising device for the detection of heavy water leakage since it has advantages on real-time monitoring and early detection for nuclear safety.

  9. An Experimental Investigation of Leak Rate Performance of a Subscale Candidate Elastomer Docking Space Seal

    Science.gov (United States)

    Garafolo, Nicholas G.; Daniels, Christopher C.

    2011-01-01

    A novel docking seal was developed for the main interface seal of NASA s Low Impact Docking System (LIDS). This interface seal was designed to maintain acceptable leak rates while being exposed to the harsh environmental conditions of outer space. In this experimental evaluation, a candidate docking seal assembly called Engineering Development Unit (EDU58) was characterized and evaluated against the Constellation Project leak rate requirement. The EDU58 candidate seal assembly was manufactured from silicone elastomer S0383-70 vacuum molded in a metal retainer ring. Four seal designs were considered with unique characteristic heights. The leak rate performance was characterized through a mass point leak rate method by monitoring gas properties within an internal control volume. The leakage performance of the seals were described herein at representative docking temperatures of -50, +23, and +50 C for all four seal designs. Leak performance was also characterized at 100, 74, and 48 percent of full closure. For all conditions considered, the candidate seal assemblies met the Constellation Project leak rate requirement.

  10. Field tests and commercialization of natural gas leak detectors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, D S; Jeon, J S; Kim, K D; Cho, Y A [R and D Center, Korea Gas Corporation, Ansan (Korea)

    1999-09-01

    Objectives - (1) fields test of industrial gas leak detection monitoring system. (2) commericialization of residential gas leak detector. Contents - (1) five sets of gas leak detection monitoring system were installed at natural gas transmition facilities and tested long term stability and their performance. (2) improved residential gas leak detector was commercialised. Expected benefits and application fields - (1) contribution to the improvement of domestic gas sensor technology. (2) localization of fabrication technology for gas leak detectors. 23 refs., 126 figs., 37 tabs.

  11. Proton dynamics in cancer.

    Science.gov (United States)

    Huber, Veronica; De Milito, Angelo; Harguindey, Salvador; Reshkin, Stephan J; Wahl, Miriam L; Rauch, Cyril; Chiesi, Antonio; Pouysségur, Jacques; Gatenby, Robert A; Rivoltini, Licia; Fais, Stefano

    2010-06-15

    Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth.Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC) in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  12. Proton dynamics in cancer

    Directory of Open Access Journals (Sweden)

    Pouysségur Jacques

    2010-06-01

    Full Text Available Abstract Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth. Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  13. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  14. Journal of Proton Therapy

    Directory of Open Access Journals (Sweden)

    Editorial Office

    2015-01-01

    Full Text Available Journal of Proton Therapy (JPT is an international open access, peer-reviewed journal, which publishes original research, technical reports, reviews, case reports, editorials, and other materials on proton therapy with focus on radiation oncology, medical physics, medical dosimetry, and radiation therapy.No article processing/submission feeNo publication feePeer-review completion within 3-6 weeksImmediate publication after the completion of final author proofreadDOI assignment for each published articleFree access to published articles for all readers without any access barriers or subscriptionThe views and opinions expressed in articles are those of the author/s and do not necessarily reflect the policies of the Journal of Proton Therapy.Authors are encouraged to submit articles for publication in the inaugural issue of the Journal of Proton Therapy by online or email to editor@protonjournal.comOfficial Website of Journal of Proton Therapy: http://www.protonjournal.org/

  15. Remote leak localization approach for fusion machines

    International Nuclear Information System (INIS)

    Durocher, Au.; Bruno, V.; Chantant, M.; Gargiulo, L.; Gherman, T.; Hatchressian, J.-C.; Houry, M.; Le, R.; Mouyon, D.

    2013-01-01

    Highlights: ► Description of leaks issue. ► Selection of leak localization concepts. ► Qualification of leak localization concepts. -- Abstract: Fusion machine operation requires high-vacuum conditions and does not tolerate water or gas leak in the vacuum vessels, even if they are micrometric. Tore Supra, as a fully actively cooled tokamak, has got a large leak management experience; 34 water leaks occurred since the beginning of its operation in 1988. To handle this issue, after preliminary machine protection phases, the current process for leak localization is based on water or helium pressurization network by network. It generally allows the identification of a set of components where the leakage element is located. However, the unique background of CEA-IRFM laboratory points needs of accuracy and promptness out in the leak localization process. Moreover, in-vessel interventions have to be performed trying to minimize time and risks for the persons. They are linked to access conditions, radioactivity, tracer gas high pressure and vessel conditioning. Remote operation will be one of the ways to improve these points on future fusion machines. In this case, leak sensors would have to be light weight devices in order to be integrated on a carrier or to be located outside with a sniffing process set up. A leak localization program is on-going at CEA-IRFM Laboratory with the first goal of identifying and characterizing relevant concepts to localize helium or water leaks on ITER. In the same time, CEA has developed robotic carrier for effective in-vessel intervention in a hostile environment. Three major tests campaigns with the goal to identify leak sensors have been achieved on several CEA test-beds since 2010. Very promising results have been obtained: relevant scenario of leak localization performed, concepts tested in a high volume test-bed called TITAN, and, in several conditions of pressure and temperature (ultrahigh vacuum to atmospheric pressure and 20

  16. Remote leak localization approach for fusion machines

    Energy Technology Data Exchange (ETDEWEB)

    Durocher, Au., E-mail: aurelien.durocher@cea.fr [CEA-IRFM, F-13108 Saint Paul-Lez-Durance (France); Bruno, V.; Chantant, M.; Gargiulo, L. [CEA-IRFM, F-13108 Saint Paul-Lez-Durance (France); Gherman, T. [Floralis UJF Filiale, F-38610 Gières (France); Hatchressian, J.-C.; Houry, M.; Le, R.; Mouyon, D. [CEA-IRFM, F-13108 Saint Paul-Lez-Durance (France)

    2013-10-15

    Highlights: ► Description of leaks issue. ► Selection of leak localization concepts. ► Qualification of leak localization concepts. -- Abstract: Fusion machine operation requires high-vacuum conditions and does not tolerate water or gas leak in the vacuum vessels, even if they are micrometric. Tore Supra, as a fully actively cooled tokamak, has got a large leak management experience; 34 water leaks occurred since the beginning of its operation in 1988. To handle this issue, after preliminary machine protection phases, the current process for leak localization is based on water or helium pressurization network by network. It generally allows the identification of a set of components where the leakage element is located. However, the unique background of CEA-IRFM laboratory points needs of accuracy and promptness out in the leak localization process. Moreover, in-vessel interventions have to be performed trying to minimize time and risks for the persons. They are linked to access conditions, radioactivity, tracer gas high pressure and vessel conditioning. Remote operation will be one of the ways to improve these points on future fusion machines. In this case, leak sensors would have to be light weight devices in order to be integrated on a carrier or to be located outside with a sniffing process set up. A leak localization program is on-going at CEA-IRFM Laboratory with the first goal of identifying and characterizing relevant concepts to localize helium or water leaks on ITER. In the same time, CEA has developed robotic carrier for effective in-vessel intervention in a hostile environment. Three major tests campaigns with the goal to identify leak sensors have been achieved on several CEA test-beds since 2010. Very promising results have been obtained: relevant scenario of leak localization performed, concepts tested in a high volume test-bed called TITAN, and, in several conditions of pressure and temperature (ultrahigh vacuum to atmospheric pressure and 20

  17. SINGLE-SHELL TANKS LEAK INTEGRITY ELEMENTS/SX FARM LEAK CAUSES AND LOCATIONS - 12127

    Energy Technology Data Exchange (ETDEWEB)

    VENETZ TJ; WASHENFELDER D; JOHNSON J; GIRARDOT C

    2012-01-25

    Washington River Protection Solutions, LLC (WRPS) developed an enhanced single-shell tank (SST) integrity project in 2009. An expert panel on SST integrity was created to provide recommendations supporting the development of the project. One primary recommendation was to expand the leak assessment reports (substitute report or LD-1) to include leak causes and locations. The recommendation has been included in the M-045-9IF Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) as one of four targets relating to SST leak integrity. The 241-SX Farm (SX Farm) tanks with leak losses were addressed on an individual tank basis as part of LD-1. Currently, 8 out of 23 SSTs that have been reported to having a liner leak are located in SX Farm. This percentage was the highest compared to other tank farms which is why SX Farm was analyzed first. The SX Farm is comprised of fifteen SSTs built 1953-1954. The tanks are arranged in rows of three tanks each, forming a cascade. Each of the SX Farm tanks has a nominal I-million-gal storage capacity. Of the fifteen tanks in SX Farm, an assessment reported leak losses for the following tanks: 241-SX-107, 241-SX-108, 241-SX-109, 241-SX-111, 241-SX-112, 241-SX-113, 241-SX-114 and 241-SX-115. The method used to identify leak location consisted of reviewing in-tank and ex-tank leak detection information. This provided the basic data identifying where and when the first leaks were detected. In-tank leak detection consisted of liquid level measurement that can be augmented with photographs which can provide an indication of the vertical leak location on the sidewall. Ex-tank leak detection for the leaking tanks consisted of soil radiation data from laterals and drywells near the tank. The in-tank and ex-tank leak detection can provide an indication of the possible leak location radially around and under the tank. Potential leak causes were determined using in-tank and ex-tank information that is not directly related to

  18. Single-Shell Tanks Leak Integrity Elements/ SX Farm Leak Causes and Locations - 12127

    Energy Technology Data Exchange (ETDEWEB)

    Girardot, Crystal [URS- Safety Management Solutions, Richland, Washington 99352 (United States); Harlow, Don [ELR Consulting Richland, Washington 99352 (United States); Venetz, Theodore; Washenfelder, Dennis [Washington River Protection Solutions, LLC Richland, Washington 99352 (United States); Johnson, Jeremy [U.S. Department of Energy, Office of River Protection Richland, Washington 99352 (United States)

    2012-07-01

    Washington River Protection Solutions, LLC (WRPS) developed an enhanced single-shell tank (SST) integrity project in 2009. An expert panel on SST integrity was created to provide recommendations supporting the development of the project. One primary recommendation was to expand the leak assessment reports (substitute report or LD-1) to include leak causes and locations. The recommendation has been included in the M-045-91F Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) as one of four targets relating to SST leak integrity. The 241-SX Farm (SX Farm) tanks with leak losses were addressed on an individual tank basis as part of LD-1. Currently, 8 out of 23 SSTs that have been reported to having a liner leak are located in SX Farm. This percentage was the highest compared to other tank farms which is why SX Farm was analyzed first. The SX Farm is comprised of fifteen SSTs built 1953-1954. The tanks are arranged in rows of three tanks each, forming a cascade. Each of the SX Farm tanks has a nominal 1-million-gal storage capacity. Of the fifteen tanks in SX Farm, an assessment reported leak losses for the following tanks: 241-SX-107, 241-SX-108, 241-SX-109, 241-SX- 111, 241-SX-112, 241-SX-113, 241-SX-114 and 241-SX-115. The method used to identify leak location consisted of reviewing in-tank and ex-tank leak detection information. This provided the basic data identifying where and when the first leaks were detected. In-tank leak detection consisted of liquid level measurement that can be augmented with photographs which can provide an indication of the vertical leak location on the sidewall. Ex-tank leak detection for the leaking tanks consisted of soil radiation data from laterals and dry-wells near the tank. The in-tank and ex-tank leak detection can provide an indication of the possible leak location radially around and under the tank. Potential leak causes were determined using in-tank and ex-tank information that is not directly related to

  19. Standard practice for leaks using ultrasonics

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 Practice A, Pressurization—This practice covers procedures for calibration of ultrasonic instruments, location, and estimated measurements of gas leakage to atmosphere by the airborne ultrasonic technique. 1.2 In general practice this should be limited to leaks detected by two classifications of instruments, Class I and Class II. Class I instruments should have a minimum detectable leak rate of 6.7 × 10−7 mol/s (1.5 × 10−2 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Class II instruments should have a minimal detectable leak rate of 6.7 × 10−6 mol/s (1.5 × 10−1 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Refer to Guide E432 for additional information. 1.3 Practice B, Ultrasonic Transmitter—For object under test not capable of being pressurized but capable of having ultrasonic tone placed/injected into the test area to act as an ultrasonic leak trace source. 1.3.1 This practice is limited to leaks producing leakage o...

  20. Leak processing system for valve gland portion

    International Nuclear Information System (INIS)

    Nishino, Masami

    1990-01-01

    When a process fluid for a valve to be checked is at such a normal temperature as during reactor operation, leaked fluid can be detected depending on the temperature increase accompanying the leakage. However, detection is difficult if the temperature of the process fluid for the valve to be checked is low and, if leakage is detected after the reactor start-up, repair has to be applied after the shutdown of the plant. Then, gland leak is detected by detecting the pressure instead of the temperature in the pipeline system and the leak flow rate is calculated based on the pressure. As a result, leakage is detected irrespective of the temperature of the leaked fluid and, for instance, leakage can be detected even in a case where the temperature is not high as in the case of pressure proof test for the pressure vessel before start-up. It can contribute much to the improvement of the plant operation efficiency and can determine the leak flow rate at a high accuracy. (N.H.)

  1. Primary flow meter for calibrating a sniffer test leak artefact by a pressure rise method

    Science.gov (United States)

    Arai, Kenta; Yoshida, Hajime

    2014-10-01

    Sniffer tests are used to locate leaks in equipment during operation. The sensitivity of a sniffer leak detector must be calibrated against a known gas flow to atmospheric pressure generated by a sniffer test leak artefact. We have developed a primary flow meter for calibrating gas flows to atmospheric pressure through the leak artefact. The flow meter is based on a pressure rise method and two chambers are used to measure the pressure rise with small uncertainty even at atmospheric pressure. The calibration range of the flow rate is 5 × 10-7 Pa m3 s-1 to 7 × 10-4 Pa m3 s-1 to atmospheric pressure at 23.0 °C with a minimum uncertainty of 1.4% (k = 2), as well as 4 × 10-8 Pa m3 s-1 to 5 × 10-4 Pa m3 s-1 to a vacuum at 23.0 °C. The long term stability of the flow meter was determined as 0.41% by repeated measurements of the conductance of the leak artefact. In case of the flow rate into a vacuum, the flow meter was successfully linked to the international reference value of CCM.P-K12 by a lab-internal comparison.

  2. Recent Progress in Technology of Leak detection

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. K.; Kim, S. H.; Cho, J. W.; Joo, Y. S.; Yang, D. J

    2005-07-15

    It is very important to check for leakage points of fluids and gases on primary pressure boundary of nuclear power plants in order to maintain and manage various structures safely. Even though much investigation has been performed by a number of researchers, there are a lot of problems to detect the leakage under some areas to which people can not approach. In particular, it is certainly necessary to find the leakage point in order to repair and replace the pressure boundaries. In this report, the basic principle and application situations for the development of the leak detection system which can detect micro-leaks are introduced. As the technologies and performances of recent sensors have been improving, the application range of leak detection has been increasing steadily. Therefore the sensor technologies written in this report will be able to contribute to nuclear safety to detect the leakage rate and the leakage point with an on-line monitoring system in the near future.

  3. Location of leaks in pressurized underground pipelines

    International Nuclear Information System (INIS)

    Eckert, E.G.; Maresca, J.W. Jr.

    1993-01-01

    Millions of underground storage tanks (UST) are used to store petroleum and other chemicals. The pressurized underground pipelines associated with USTs containing petroleum motor fuels are typically 2 in. in diameter and 50 to 200 ft in length. These pipelines typically operate at pressures of 20 to 30 psi. Longer lines, with diameters up to 4 in., are found in some high-volume facilities. There are many systems that can be used to detect leaks in pressurized underground pipelines. When a leak is detected, the first step in the remediation process is to find its location. Passive-acoustic measurements, combined with advanced signal-processing techniques, provide a nondestructive method of leak location that is accurate and relatively simple, and that can be applied to a wide variety of pipelines and pipeline products

  4. Enhanced leak detection risk model development

    Energy Technology Data Exchange (ETDEWEB)

    Harron, Lorna; Barlow, Rick; Farquhar, Ted [Enbridge Pipelines Inc., Edmonton, Alberta (Canada)

    2010-07-01

    Increasing concerns and attention to pipeline safety have engaged pipeline companies and regulatory agencies to extend their approaches to pipeline integrity. The implementation of High Consequence Areas (HCAs) has especially had an impact on the development of integrity management protocols (IMPs) for pipelines. These IMPs can require that a risk based assessment of integrity issues be applied to specific HCA risk factors. This paper addresses the development of an operational risk assessment approach for pipeline leak detection requirements for HCAs. A detailed risk assessment algorithm that includes 25 risk variables and 28 consequence variables was developed for application to all HCA areas. This paper describes the consultative process that was used to workshop the development of this algorithm. Included in this description is how the process addressed various methods of leak detection across a wide variety of pipelines. The paper also looks at development challenges and future steps in applying operation risk assessment techniques to mainline leak detection risk management.

  5. Remote leak detection for the TFTR

    International Nuclear Information System (INIS)

    Walthers, C.R.

    1977-01-01

    The planned design for the TFTR (TOKAMAK Fusion Test Reactor) remote leak detection system consists of a central console which controls the application of tracer gas to possible leak areas. Seals are tested by admitting tracer gas to machined cavities on the atmospheric side of the seal. The tracer gas is brought to the seal cavity by 1 / 8 -inch diameter tubes which connect to local tracer gas/vacuum manifolds located outside the protective radiation shielding. Vacuum shell walls and welds are checked by flowing tracer gas through annular heating/cooling passages. The detector will be either an MSLD (mass spectrometer leak detector) or an RGA (residual gas analyzer), the location of which is not finalized. Feasibility tests performed and planned include response and sensitivity measurements of possible tubing/detector configurations with several tracer gases

  6. Combustion suppressing device for leaked sodium

    International Nuclear Information System (INIS)

    Ooto, Akihiro.

    1985-01-01

    Purpose: To suppress the atmospheric temperature to secure the building safety and shorten the recovery time after the leakage in a chamber for containing sodium leaked from coolant circuit equipments or pipeways of LMFBR type rector by suppressing the combustion of sodium contained in the chamber. Constitution: To the inner wall of a chamber for containing sodium handling equipments, are vertically disposed a panel having a coolant supply port at the upper portion and a coolant discharge port at the lower portion thereof and defined with a coolant flowing channel and a panel for sucking the coolant discharged from the abovementioned panel and exhausting the same externally. Further, a corrugated combustion suppressing plate having apertures for draining the condensated leaked sodium is disposed near the sodium handling equipments. If ruptures are resulted to the sodium handling equipments or pipeway, leaked sodium is passed through the drain apertures in the suppressing plate and stored at the bottom of the containing chamber. (Horiuchi, T.)

  7. Novel Methods of Hydrogen Leak Detection

    International Nuclear Information System (INIS)

    Pushpinder S Puri

    2006-01-01

    With the advent of the fuel cell technology and a drive for clean fuel, hydrogen gas is emerging as a leading candidate for the fuel of choice. For hydrogen to become a consumer fuel for automotive and domestic power generation, safety is paramount. It is, therefore, desired to have a method and system for hydrogen leak detection using odorant which can incorporate a uniform concentration of odorant in the hydrogen gas, when odorants are mixed in the hydrogen storage or delivery means. It is also desired to develop methods where the odorant is not added to the bulk hydrogen, keeping it free of the odorization additives. When odorants are not added to the hydrogen gas in the storage or delivery means, methods must be developed to incorporate odorant in the leaking gas so that leaks can be detected by small. Further, when odorants are not added to the stored hydrogen, it may also be desirable to observe leaks by sight by discoloration of the surface of the storage or transportation vessels. A series of novel solutions are proposed which address the issues raised above. These solutions are divided into three categories as follows: 1. Methods incorporating an odorant in the path of hydrogen leak as opposed to adding it to the hydrogen gas. 2. Methods where odorants are generated in-situ by chemical reaction with the leaking hydrogen 3. Methods of dispensing and storing odorants in high pressure hydrogen gas which release odorants to the gas at a uniform and predetermined rates. Use of one or more of the methods described here in conjunction with appropriate engineering solutions will assure the ultimate safety of hydrogen use as a commercial fuel. (authors)

  8. CT assessment of anastomotic bowel leak

    International Nuclear Information System (INIS)

    Power, N.; Atri, M.; Ryan, S.; Haddad, R.; Smith, A.

    2007-01-01

    Aim: To evaluate the predictors of clinically important gastrointestinal anastomotic leaks using multidetector computed tomography (CT). Subjects and methods: Ninety-nine patients, 73 with clinical suspicion of anastomotic bowel leak and 26 non-bowel surgery controls underwent CT to investigate postoperative sepsis. Fifty patients had undergone large bowel and 23 small bowel anastomoses. The time interval from surgery was 3-30 days (mean 10 ± 5.9 SD) for the anastomotic group and 3-40 days (mean 14 ± 11 SD) for the control group (p = 0.3). Two radiologists blinded to the final results reviewed the CT examinations in consensus and recorded the presence of peri-anastomotic air, fluid or combination of the two; distant loculated fluid or combination of fluid and air; free air or fluid; and intestinal contrast leak. Final diagnosis of clinically important anastomotic leak (CIAL) was confirmed at surgery or by chart review of predetermined clinical and laboratory criteria. Results: The prevalence of CIAL in the group undergoing CT was 31.5% (23/73). The CT examinations with documented leak were performed 5-28 (mean; 11.4 ± 6 SD) days after surgery. Nine patients required repeat operation, 10 percutaneous abscess drainage, two percutaneous drainage followed by surgery, and two prolonged antibiotic treatment and total parenteral nutrition (TPN). Of the CT features examined, only peri-anastomotic loculated fluid containing air was more frequently seen in the CIAL group as opposed to the no leak group (p = 0.04). There was no intestinal contrast leakage in this cohort. Free air was present up to 9 days and loculated air up to 26 days without CIAL. Conclusion: Most postoperative CT features overlap between patients with and without CIAL. The only feature seen statistically more frequently with CIAL is peri-anastomotic loculated fluid containing air

  9. CT assessment of anastomotic bowel leak

    Energy Technology Data Exchange (ETDEWEB)

    Power, N. [Department of Radiology, Sunnybrook Hospital, Toronto, Ontario M4N 3M5 (Canada); Atri, M. [Department of Radiology, Sunnybrook Hospital, Toronto, Ontario M4N 3M5 (Canada)]. E-mail: mostafa.atri@sw.ca; Ryan, S. [Department of Radiology, Sunnybrook Hospital, Toronto, Ontario M4N 3M5 (Canada); Haddad, R. [Department of Surgery, Sunnybrook Hospital, Toronto, Ontario M4N 3M5 (Canada); Smith, A. [Department of Surgery, Sunnybrook Hospital, Toronto, Ontario M4N 3M5 (Canada)

    2007-01-15

    Aim: To evaluate the predictors of clinically important gastrointestinal anastomotic leaks using multidetector computed tomography (CT). Subjects and methods: Ninety-nine patients, 73 with clinical suspicion of anastomotic bowel leak and 26 non-bowel surgery controls underwent CT to investigate postoperative sepsis. Fifty patients had undergone large bowel and 23 small bowel anastomoses. The time interval from surgery was 3-30 days (mean 10 {+-} 5.9 SD) for the anastomotic group and 3-40 days (mean 14 {+-} 11 SD) for the control group (p = 0.3). Two radiologists blinded to the final results reviewed the CT examinations in consensus and recorded the presence of peri-anastomotic air, fluid or combination of the two; distant loculated fluid or combination of fluid and air; free air or fluid; and intestinal contrast leak. Final diagnosis of clinically important anastomotic leak (CIAL) was confirmed at surgery or by chart review of predetermined clinical and laboratory criteria. Results: The prevalence of CIAL in the group undergoing CT was 31.5% (23/73). The CT examinations with documented leak were performed 5-28 (mean; 11.4 {+-} 6 SD) days after surgery. Nine patients required repeat operation, 10 percutaneous abscess drainage, two percutaneous drainage followed by surgery, and two prolonged antibiotic treatment and total parenteral nutrition (TPN). Of the CT features examined, only peri-anastomotic loculated fluid containing air was more frequently seen in the CIAL group as opposed to the no leak group (p = 0.04). There was no intestinal contrast leakage in this cohort. Free air was present up to 9 days and loculated air up to 26 days without CIAL. Conclusion: Most postoperative CT features overlap between patients with and without CIAL. The only feature seen statistically more frequently with CIAL is peri-anastomotic loculated fluid containing air.

  10. LMFBR steam generator leak detection development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Magee, P M; Gerrels, E E; Greene, D A [General Electric Company, Sunnyvale, CA (United States); McKee, J [Argonne National Laboratory, Argonne, IL (United States)

    1978-10-01

    Leak detection for Liquid Metal Fast Breeder Reactor steam generators is an important economic factor in the shutdown, repair and restart of a plant. Development of leak detection systems in the U.S. has concentrated on four areas: (1) chemical (H{sub 2} and O{sub 2}) leak detection meters; (2) acoustic leak detection/location techniques; (3) investigation of leak behavior (enlargement, damage effects, plugging and unplugging); and (4) data management for plant operations. This paper discusses the status, design aspects, and applications of leak detection technology for LMFBR plants. (author)

  11. LMFBR steam generator leak detection development in the United States

    International Nuclear Information System (INIS)

    Magee, P.M.; Gerrels, E.E.; Greene, D.A.; McKee, J.

    1978-01-01

    Leak detection for Liquid Metal Fast Breeder Reactor steam generators is an important economic factor in the shutdown, repair and restart of a plant. Development of leak detection systems in the U.S. has concentrated on four areas: (1) chemical (H 2 and O 2 ) leak detection meters; (2) acoustic leak detection/location techniques; (3) investigation of leak behavior (enlargement, damage effects, plugging and unplugging); and (4) data management for plant operations. This paper discusses the status, design aspects, and applications of leak detection technology for LMFBR plants. (author)

  12. Fuel leak detection on large transport airplanes

    OpenAIRE

    Behbahani-Pour, M.J.; Radice, G.

    2016-01-01

    Fuel leakage has the risk of being ignited by external ignition sources, and therefore it is important to detect\\ud any fuel leakage before the departure of the aircraft. Currently, there are no fuel leak detection systems installed\\ud on commercial aircrafts, to detect fuel tank leakage, while only a small number of more recent aircraft, have a fuel\\ud monitoring system, that generates a fuel leak-warning message in cockpit in the case of fuel imbalance between the\\ud tanks. The approach pro...

  13. Technique for detecting liquid metal leaks

    International Nuclear Information System (INIS)

    Bauerle, J.E.

    1979-01-01

    In a system employing flowing liquid metal as a heat transfer medium in contact with tubular members containing a working fluid, i.e., steam, liquid metal leaks through the wall of the tubular member are detected by dislodging the liquid metal compounds forming in the tubular member at the leak locations and subsequently transporting the dislodged compound in the form of an aerosol to a detector responsive to the liquid metal compound. In the application to a sodium cooled tubular member, the detector would consist of a sodium responsive device, such as a sodium ion detector

  14. Hydrogen detection systems leak response codes

    International Nuclear Information System (INIS)

    Desmas, T.; Kong, N.; Maupre, J.P.; Schindler, P.; Blanc, D.

    1990-01-01

    A loss in tightness of a water tube inside a Steam Generator Unit of a Fast Reactor is usually monitored by hydrogen detection systems. Such systems have demonstrated in the past their ability to detect a leak in a SGU. However, the increase in size of the SGU or the choice of ferritic material entails improvement of these systems in order to avoid secondary leak or to limit damages to the tube bundle. The R and D undertaken in France on this subject is presented. (author). 11 refs, 10 figs

  15. Transanal Drainage of Coloanal Anastomotic Leaks

    Directory of Open Access Journals (Sweden)

    Bradley Sherman

    2018-01-01

    Full Text Available The conventional operative intervention for leaks following coloanal anastomoses has been proximal fecal diversion with or without take-down of anastomosis. A few of these cases are also amenable to percutaneous drainage. Ostomies created in this situation are often permanent, specifically in cases where coloanal anastomoses are taken down at the time of reoperation. We present two patients who developed perianastomotic pelvic abscesses that were treated with transanal large bore catheter drainage resulting in successful salvage of coloanal anastomoses without the need for a laparotomy or ostomy creation. We propose this to be an effective therapeutic approach to leaks involving low coloanal anastomoses in the absence of generalized peritonitis.

  16. Single-Shell Tank Leak Integrity Summary

    Energy Technology Data Exchange (ETDEWEB)

    Harlow, D. G. [Washington River Protection Solutions LLC, Richland, WA (United States); Girardot, C. L. [Washington River Protection Solutions LLC, Richland, WA (United States); Venetz, T. J. [Washington River Protection Solutions LLC, Richland, WA (United States)

    2015-03-26

    This document summarizes and evaluates the information in the Hanford Tri-Party Agreement Interim Milestone M-045-91F Targets completed between 2010 and 2015. 1) Common factors of SST liner failures (M-045-91F-T02), 2) the feasibility of testing for ionic conductivity between the inside and outside of SSTs (M-045-91F-T03, and 3) the causes, locations, and rates of leaks from leaking SSTs (M-045-91F-T04).

  17. Attacks by “Anonymous‿ WikiLeaks Proponents not Anonymous

    NARCIS (Netherlands)

    Pras, Aiko; Sperotto, Anna; Moreira Moura, Giovane; Drago, Idilio; Barbosa, R.R.R.; Sadre, R.; de Oliveira Schmidt, R.; Hofstede, R.J.; Hofstede, Rick

    2010-01-01

    On November 28, 2010, the world started watching the whistle blower website WikiLeaks to begin publishing part of the 250,000 US Embassy Diplomatic cables. These confidential cables provide an insight on U.S. international affairs from 274 different embassies, covering topics such as analysis of

  18. Proton decay theory

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1983-01-01

    Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay

  19. A Correlated Active Acoustic Leak Detection in a SFR Steam Generator

    International Nuclear Information System (INIS)

    Kim, Tae Joon; Jeong, Ji Young; Kim, Jong Man; Kim, Byung Ho; Kim, Yong Il

    2009-01-01

    The methods of acoustic leak detection are active acoustic leak detection and passive acoustic leak detection. The methods for passive acoustic leak detection are already established, but because our goal is development of passive acoustic leak detection for detecting a leakage range of small and micro leak rates, it is difficult detecting a leak in steam generator using this developed passive acoustic leak detection. Thus the acoustic leak detection system is required to be able to detect wide range of water leaks. From this view point we need to develop an active acoustic leak detection technology to be able to detect intermediate leak rates

  20. Proton therapy

    International Nuclear Information System (INIS)

    Jongen, Y.

    1995-01-01

    Ideal radiotherapy deposits a large amount of energy in the tumour volume, and none in the surrounding healthy tissues. Proton therapy comes closer to this goal because of a greater concentration of dose, well defined proton ranges and points of energy release which are precisely known - the Bragg peak1. In the past, the development of clinical proton therapy has been hampered by complexity, size, and cost. To be clinically effective, energies of several hundred MeV are required; these were previously unavailable for hospital installations, and pioneering institutions had to work with complex, inadequate equipment originally intended for nuclear physics research. Recently a number of specialist organizations and commercial companies have been working on dedicated systems for proton therapy. One, IBA of Belgium, has equipment for inhouse hospital operation which encompasses a complete therapy centre, delivered as a turnkey package and incorporating a compact, automated, higher energy cyclotron with isocentric gantries. Their system will be installed at Massachusetts General Hospital, Boston. The proton therapy system comprises: - a 235 MeV isochronous cyclotron to deliver beams of up to 1.5 microamps, but with a hardware limitation to restrict the maximum possible dose; - variable energy beam (235 to 70 MeV ) with energy spread and emittance verification; - a beam transport and switching system to connect the exit of the energy selection system to the entrances of a number of gantries and fixed beamlines. Along the beam transport system, the beam characteristics are monitored with non-interceptive multiwire ionization chambers for automatic tuning; - gantries fitted with nozzles and beamline elements for beam control; both beam scattering and beam wobbling techniques are available for shaping the beam;

  1. Humos monitoring system of leaks in to the containment atmosphere

    International Nuclear Information System (INIS)

    Matal, O.; Zaloudek, J.; Matal, O. Jr.; Klinga, J.; Brom, J.

    1997-01-01

    HUmidity MOnitoring System (HUMOS) has been developed and designed to detect the presence of leak in selected primary circuit high energy pipelines and components that are evaluated from the point of view of Leak Before Break (LBB) requirements. It also requires to apply technical tools for detection and identification of coolant leaks from primary circuit and components of PWRs reactors. Safety significant of leaks depend on: leak source (location); leak rate, and leak duration. Therefore to detect and monitor coolant leaks in to the containment atmosphere during reactor operation is one of important safety measures. As potential leak sources flange connection in the upper head region of WWER reactors can be considered. HUMOS does not rely on the release of radioactivity to detect leaks but rather the relies on detection of moisture in the air resulting from a primary boundary leak. Because HUMOS relies on moisture and temperature detection, leaks can be detected without requiring the reactor to be critical. Therefore leaks can be detected during integrity pressure tests and any other mode of operation provided the reactor ventilation system is operating and primary circuit and components are pressurized. 3 figs

  2. Leak-before-break diagrams using simple plastic limit load criteria for pipes with circumferential cracks

    International Nuclear Information System (INIS)

    Goerner, F.; Munz, D.

    1984-01-01

    Simple criteria for local and global instabilities were used to calculate leak-before-break-diagrams for load-controlled deformations. Relations between the tension and bending stresses in the uncracked pipe and the critical crack angle α/sub c/, below which complete fracture cannot occur, were developed for combined loading by internal pressure and external tension and bending. The different assumptions made for local and global instability lead to similar conclusions about the allowable crack length for leak-before-break behavior. It was not the intention of this paper to compare the conclusions with experimental results available

  3. Percutaneous Hepaticojejunostomy Using a Radiofrequency Wire for Management of a Postoperative Bile Leak

    Energy Technology Data Exchange (ETDEWEB)

    Close, Orrie N. [University of Pittsburgh School of Medicine, Interventional Radiology, Department of Radiology (United States); Akinwande, Olaguoke [Johns Hopkins University, Division of Interventional Radiology (United States); Varma, Rakesh K.; Santos, Ernesto; Kim, Hyun S., E-mail: kevin.kim@yale.edu [University of Pittsburgh School of Medicine, Interventional Radiology, Department of Radiology (United States)

    2017-01-15

    Postoperative biliary complications following extensive hepatic resections are complex, often requiring a multidisciplinary team approach. We describe a case of a free bile duct leak following extended right hepatectomy and surgical hepaticojejunostomy treated with percutaneous transhepatic hepaticojejunostomy in which a radiofrequency guidewire was used to gain enteral access. A modified internal/external biliary catheter was left in place. The patient was enrolled in a benign biliary stricture protocol, and 8 months later, the catheter was removed following a normal cholangiogram and biliary manometric perfusion testing. At 3-month follow-up after catheter removal, the patient is asymptomatic with no clinical, biochemical, or radiographic evidence of biliary leak or obstruction.

  4. Validation of sleeve of straight union type B for leaks

    Energy Technology Data Exchange (ETDEWEB)

    Teutonico, Mauricio; Fazzini, Pablo [Gie S.A., Buenos Aires (Argentina)

    2009-07-01

    Analytic study and experimental validation of type B sleeve with overlapping, were done in order to determine whether they are suitable for used as permanent leaks repair in hydrocarbons transport lines. All relevant background of this type of repair was analyzed, following the guidelines defined by applicable regulations (ASME B31.8 and ASME B31.4) and modeled by finite elements methods. Solicitations under internal pressure of each one of the reinforcement parts were analyzed. All solicitations involved in welded unions were studied, so as the reinforcement effectiveness when it is filled with internal gap filler. Experimental tests were developed, consisted on the reinforcement installation upon damaged pipes and the following hydrostatic test. These tests were assisted by a digitalized measurement, to determine the solicitations at different parts of the reinforcement; strain gauges were used for this task. (author)

  5. Localized leak detection utilizing moisture sensitive tape

    International Nuclear Information System (INIS)

    Riddle, P.

    1984-01-01

    Moisture sensitive tape (MST) has been used in various nuclear power plants to detect leaks in reactor piping systems. The sensor assembly consists of MST, transponder, and sensor carrier, and is installed on the exterior of thermal insulation. The components, applications, installation, and purchasing information are discussed in the paper

  6. Steam generator leak detection using acoustic method

    International Nuclear Information System (INIS)

    Goluchko, V.V.; Sokolov, B.M.; Bulanov, A.N.

    1982-05-01

    The main requirements to meet by a device for leak detection in sodium - water steam generators are determined. The potentialities of instrumentation designed based on the developed requirements have been tested using a model of a 550 kw steam generator [fr

  7. GASFLOW analysis of a tritium leak accident

    International Nuclear Information System (INIS)

    Farman, R.F.; Fujita, R.K.; Travis, J.R.

    1994-01-01

    The consequences of an earthquake-induced fire involving a tritium leak were analyzed using the GASFLOW computer code. Modeling features required by the analysis include ventilation boundary conditions, flow of a gas mixture in an enclosure containing obstacles, thermally induced buoyancy, and combustion phenomena. (author). 2 refs., 6 figs

  8. GASFLOW analysis of a tritium leak accident

    International Nuclear Information System (INIS)

    Farman, R.F.; Fujita, R.K.; Travis, J.R.

    1994-01-01

    The consequences of an earthquake-induced fire involving a tritium leak were analyzed using the GASFLOW computer code. Modeling features required by the analysis include ventilation boundary conditions, flow of a gas mixture in an enclosure containing obstacles, thermally induced buoyancy, and combustion phenomena

  9. Detecting gas leaks by ultrasonic emission

    DEFF Research Database (Denmark)

    Rasmussen, Karsten Bo; Henriksen, Eigil

    1997-01-01

    The emission of noise in the frequency range 10 kHz to 25.6 kHz from an experimental gas leak in a flanged joint has been experimentally investigated. The overall conclusion is that the emitted noise is almost frequency independent in level within the considered frequency range.A small PC program...

  10. A Quick Guide to Paravalvular Leak Closure

    Science.gov (United States)

    Gafoor, Sameer; Franke, Jennifer; Bertog, Stefan; Lam, Simon; Vaskelyte, Laura; Hofmann, Ilona; Matic, Predrag

    2015-01-01

    Paravalvular leak (PVL) is a seldomly covered aspect of structural heart disease. However, this is a condition that frequently presents after valvular replacement. This article will cover the diagnosising and treating PVL (i.e. imaging, access, and device selection). In addition, specific aspects of aortic and mitral PVL closure will be covered in this review. PMID:29588686

  11. Developments in steam generator leak detection at Ontario Hydro

    Energy Technology Data Exchange (ETDEWEB)

    Maynard, K.J.; Singh, V.P. [Ontario Hydro Technologies, Toronto, Ontario (Canada)

    1998-07-01

    A method for locating small tube leaks in steam generators has been developed and implemented at Ontario Hydro. The technique utilizes both helium leak detection and moisture leak detection. The combination of these two methods allows tube leaks to be detected in any part of the tube bundle, including those submerged below water near the tubesheet. The estimated detection limits for the helium and moisture leak detection systems are 0.001 kg/hr and 0.05 kg/hr respectively, expressed as leak rates measured at typical boiler operating conditions. This technology is best utilized in situations where the leak rate under operating conditions is smaller than the practical limit for fluorescein dye techniques ({approx}2 kg/hour). Other novel techniques have been utilized to increase the reliability and speed of the boiler leak search process. These include the use of argon carrier gas to stabilize the buoyant helium gas in the boiler secondary. (author)

  12. Developments in steam generator leak detection at Ontario Hydro

    International Nuclear Information System (INIS)

    Maynard, K.J.; Singh, V.P.

    1998-01-01

    A method for locating small tube leaks in steam generators has been developed and implemented at Ontario Hydro. The technique utilizes both helium leak detection and moisture leak detection. The combination of these two methods allows tube leaks to be detected in any part of the tube bundle, including those submerged below water near the tubesheet. The estimated detection limits for the helium and moisture leak detection systems are 0.001 kg/hr and 0.05 kg/hr respectively, expressed as leak rates measured at typical boiler operating conditions. This technology is best utilized in situations where the leak rate under operating conditions is smaller than the practical limit for fluorescein dye techniques (∼2 kg/hour). Other novel techniques have been utilized to increase the reliability and speed of the boiler leak search process. These include the use of argon carrier gas to stabilize the buoyant helium gas in the boiler secondary. (author)

  13. Development of pressure boundaries leak detection technology for nuclear reactor

    International Nuclear Information System (INIS)

    Zhang Yao; Zhang Dafa; Chen Dengke; Zhang Liming

    2008-01-01

    The leak detection for the pressure boundaries is an important safeguard in nuclear reactor operation. In the paper, the status and the characters on the development of the pressure boundaries leak detection technology for the nuclear reactor were reviewed, especially, and the advance of the radiation leak detection technology and the acoustic emission leak detection technology were analyzed. The new advance trend of the leak detection technology was primarily explored. According to the analysis results, it is point out that the advancing target of the leak detection technology is to enhance its response speed, sensitivity, and reliability, and to provide effective information for operator and decision-maker. The realization of the global leak detection and the whole life cycle health monitoring for the nuclear boundaries is a significant advancing tendency of the leak detection technology. (authors)

  14. Enhancement of leak rate estimation model for corroded cracked thin tubes

    International Nuclear Information System (INIS)

    Chang, Y.S.; Jeong, J.U.; Kim, Y.J.; Hwang, S.S.; Kim, H.P.

    2010-01-01

    During the last couple of decades, lots of researches on structural integrity assessment and leak rate estimation have been carried out to prevent unanticipated catastrophic failures of pressure retaining nuclear components. However, from the standpoint of leakage integrity, there are still some arguments for predicting the leak rate of cracked components due primarily to uncertainties attached to various parameters in flow models. The purpose of present work is to suggest a leak rate estimation method for thin tubes with artificial cracks. In this context, 23 leak rate tests are carried out for laboratory generated stress corrosion cracked tube specimens subjected to internal pressure. Engineering equations to calculate crack opening displacements are developed from detailed three-dimensional elastic-plastic finite element analyses and then a simplified practical model is proposed based on the equations as well as test data. Verification of the proposed method is done through comparing leak rates and it will enable more reliable design and/or operation of thin tubes.

  15. Performance evaluation of PFBR wire type sodium leak detectors

    International Nuclear Information System (INIS)

    Vijayakumar, G.; Rajan, K.K.; Nashine, B.K.; Chandramouli, S.; Madhusoodanan, K.; Kalyanasundaram, P.

    2011-01-01

    Highlights: → Performance evaluation of wire type leak detectors was conducted in LEENA facility by creating sodium leaks. → The lowest leak rate of 214 g/h was detected in 50 min and the highest detection time was 6 h for a leak rate of 222 g/h. → Factors affecting the leak detection time are packing density of thermal insulation, layout of heater, temperature, etc. → Relationship between leak rate and detection time was established and a leak rate of 100 g/h is likely to be detected in 11.1 h. → Contact resistance of leaked sodium increased to 3.5 kilo ohms in 20 h. - Abstract: Wire type leak detectors working on conductivity principle are used for detecting sodium leak in the secondary sodium circuits of fast breeder reactors. It is required to assess the performance of these detectors and confirm that they are meeting the requirements. A test facility by name LEENA was constructed at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam to test the wire type leak detector lay out by simulating different sodium leak rates. This test facility consists of a sodium dump tank, a test vessel, interconnecting pipelines with valves, micro filter and test section with leak simulators. There are three different test sections in the test set up of length 1000 mm each. These test sections simulate piping of Prototype Fast Breeder Reactor (PFBR) secondary circuit and the wire type leak detector layout in full scale. All test sections are provided with leak simulators. A leak simulator consists of a hole of size one mm drilled in the test section and closed with a tapered pin. The tapered pin position in the hole is adjusted by a screw mechanism and there by the annular gap of flow area is varied for getting different leak rates. Various experiments were conducted to evaluate the performance of the leak detectors by creating different sodium leak rates. This paper deals with the details of wire type leak detector layout for the secondary sodium circuit of

  16. Endoscopic management of biliary injuries and leaks

    Directory of Open Access Journals (Sweden)

    T S Chandrasekar

    2012-01-01

    Full Text Available Bile duct injuries and subsequent leaks can occur following laparoscopic and open cholecystectomies and also during other hepatobiliary surgeries. Various patient related and technical factors are implicated in the causation of biliary injuries. Over a period of twenty five years managing such patients of biliary injuries our team has found a practical approach to assess the cause of biliary injuries based on the symptoms, clinical examination and imaging. Bismuth classification is helpful in most of the cases. Immediate referral to a centre experienced in the management of bile duct injury and timely intervention is associated with improved outcomes. Resuscitation, correcting dyselectrolytemia, aspiration of undrained biloma and antibiotics take the priority in the management. The goal is to restore the bile conduit, and to prevent short and longterm complications such as biliary fistula, intra-abdominal abscess, biliary stricture, recurrent cholangitis and secondary biliary cirrhosis. Endoscopic therapy by reducing the transpapillary pressure gradient helps in reducing the leak. Endoscopic therapy with biliary sphincterotomy alone or with additional placement of a biliary stent/ nasobiliary drainage is advocated. In our tertiary care referral unit, we found endoscopic interventions are useful in situations where there is leak with associated CBD calculus or a foreign body, peripheral bile duct injury, cystic duct stump leak and partial bile duct injury with leak/ narrowing of the lumen. Endotherapy is not useful in case of complete transection (total cut off and complete stricture involving common hepatic or common bile ducts. In conclusion, endoscopic treatment can be considered a highly effective therapy and should be the first-line therapy in such patients. Though less successful, an endoscopic attempt is warranted in patients suffering from central bile duct leakages failing which surgical management is recommended.

  17. Modeling leaks from liquid hydrogen storage systems.

    Energy Technology Data Exchange (ETDEWEB)

    Winters, William Stanley, Jr.

    2009-01-01

    This report documents a series of models for describing intended and unintended discharges from liquid hydrogen storage systems. Typically these systems store hydrogen in the saturated state at approximately five to ten atmospheres. Some of models discussed here are equilibrium-based models that make use of the NIST thermodynamic models to specify the states of multiphase hydrogen and air-hydrogen mixtures. Two types of discharges are considered: slow leaks where hydrogen enters the ambient at atmospheric pressure and fast leaks where the hydrogen flow is usually choked and expands into the ambient through an underexpanded jet. In order to avoid the complexities of supersonic flow, a single Mach disk model is proposed for fast leaks that are choked. The velocity and state of hydrogen downstream of the Mach disk leads to a more tractable subsonic boundary condition. However, the hydrogen temperature exiting all leaks (fast or slow, from saturated liquid or saturated vapor) is approximately 20.4 K. At these temperatures, any entrained air would likely condense or even freeze leading to an air-hydrogen mixture that cannot be characterized by the REFPROP subroutines. For this reason a plug flow entrainment model is proposed to treat a short zone of initial entrainment and heating. The model predicts the quantity of entrained air required to bring the air-hydrogen mixture to a temperature of approximately 65 K at one atmosphere. At this temperature the mixture can be treated as a mixture of ideal gases and is much more amenable to modeling with Gaussian entrainment models and CFD codes. A Gaussian entrainment model is formulated to predict the trajectory and properties of a cold hydrogen jet leaking into ambient air. The model shows that similarity between two jets depends on the densimetric Froude number, density ratio and initial hydrogen concentration.

  18. Investigation for the sodium leak in Monju. Sodium leak and fire test-1

    International Nuclear Information System (INIS)

    Kawata, Koji; Ohno, Shuji; Miyahara, Shinya; Miyake, Osamu; Tanabe, Hiromi

    2000-08-01

    As a part of the work for investigating the sodium leak accident which occurred in the Monju reactor (hereinafter referred to as Monju) on December 8, 1995, three tests, (1) a sodium leak test, (2) a sodium leak and fire test-1, and (3) a sodium leak and fire test-II, were carried out at OEC/PEC. The main objectives of these tests were to confirm the leak and burning behavior of sodium from the damaged thermometer, and the effects of the sodium fire on the integrity of the surrounding structure. This report describes the results of the sodium fire test-I carried out as a preliminary test. The test was performed using the SOLFA-2 (Sodium Leak, Fire and Aerosol) facility on April 8, 1996. In this test, sodium heated to 480degC was leaked for approximately 1.5 hours from a leak simulating apparatus and caused to drop onto a ventilation duct and a grating with the same dimensions and layout as those in Monju. The main conclusions obtained from the test are shown below: 1) Observation from video cameras in the test revealed that in the early stages of the sodium leak, sodium dripped out of the flexible tube of the thermometer. This dripping and burning expanded in range as the sodium splashed on the duct. 2) No damage to the duct itself was detected. However, the aluminum louver frame of the ventilation duct's lower inlet was damaged. Its machine screws came off, leaving half of the grill (on the grating side) detached. 3) No large hole, like the one seen at Monju, was found when the grating was removed from the testing system for inspection, although the area centered on the point were the sodium dripped was damaged in a way indicating the first stages of grating failure. The 5mm square lattice was corroded through in some parts, and numerous blades (originally 3.2 mm thick) had become sharpened like the blade of a knife. 4) The burning pan underside thermocouple near the leak point measured 700degC in within approximately 10 minutes, and for the next hour remained

  19. Experiences with leak rate calculations methods for LBB application

    International Nuclear Information System (INIS)

    Grebner, H.; Kastner, W.; Hoefler, A.; Maussner, G.

    1997-01-01

    In this paper, three leak rate computer programs for the application of leak before break analysis are described and compared. The programs are compared to each other and to results of an HDR Reactor experiment and two real crack cases. The programs analyzed are PIPELEAK, FLORA, and PICEP. Generally, the different leak rate models are in agreement. To obtain reasonable agreement between measured and calculated leak rates, it was necessary to also use data from detailed crack investigations

  20. Experiences with leak rate calculations methods for LBB application

    Energy Technology Data Exchange (ETDEWEB)

    Grebner, H.; Kastner, W.; Hoefler, A.; Maussner, G. [and others

    1997-04-01

    In this paper, three leak rate computer programs for the application of leak before break analysis are described and compared. The programs are compared to each other and to results of an HDR Reactor experiment and two real crack cases. The programs analyzed are PIPELEAK, FLORA, and PICEP. Generally, the different leak rate models are in agreement. To obtain reasonable agreement between measured and calculated leak rates, it was necessary to also use data from detailed crack investigations.

  1. Vehicle-based Methane Mapping Helps Find Natural Gas Leaks and Prioritize Leak Repairs

    Science.gov (United States)

    von Fischer, J. C.; Weller, Z.; Roscioli, J. R.; Lamb, B. K.; Ferrara, T.

    2017-12-01

    Recently, mobile methane sensing platforms have been developed to detect and locate natural gas (NG) leaks in urban distribution systems and to estimate their size. Although this technology has already been used in targeted deployment for prioritization of NG pipeline infrastructure repair and replacement, one open question regarding this technology is how effective the resulting data are for prioritizing infrastructure repair and replacement. To answer this question we explore the accuracy and precision of the natural gas leak location and emission estimates provided by methane sensors placed on Google Street View (GSV) vehicles. We find that the vast majority (75%) of methane emitting sources detected by these mobile platforms are NG leaks and that the location estimates are effective at identifying the general location of leaks. We also show that the emission rate estimates from mobile detection platforms are able to effectively rank NG leaks for prioritizing leak repair. Our findings establish that mobile sensing platforms are an efficient and effective tool for improving the safety and reducing the environmental impacts of low-pressure NG distribution systems by reducing atmospheric methane emissions.

  2. Proton radiography to improve proton therapy treatment

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E. R.; van Goethem, Marc-Jan; van Beuzekom, M.; Klaver, T.; Visser, Jan; Brandenburg, S.; Biegun, A. K.

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)

  3. Acoustic leak detection at complicated topologies using neural netwoks

    International Nuclear Information System (INIS)

    Hessel, G.; Schmitt, W.; Weiss, F.P.

    1994-01-01

    Considering the shortcomings of all the existing leak detecting principles, a new method again based on the measurement of the leak induced sound but also applying pattern recognition is being developed. The capability of neural networks to localize leaks at the reactor pressure vessel (RPV) head of VVER-440 reactors is discussed. (orig./DG)

  4. Damage phenomena at target surface by small leak

    International Nuclear Information System (INIS)

    Jeong, Kyung Chai; Jeong, J. Y.; Kim, B. H.; Kim, T. J.; Choi, J. H.

    2001-04-01

    Design of the steam generator should be considered the safety about the sodium-water reaction occurred by water leak in heat transfer tube. Water leak mainly occurred from welding defect at the process of tube connection, the vibration of heat transfer tube bundle in steam generating system, fretting, and pin hole in original tube manufacturing. The classification of water leak divided to two parts, roughly, in case of the water leak studies. One is small leak phenomena analysis, and the other is it of large leak which was mainly treated to the evaluation on pressure increasing from hydrogen gas formed by sodium-water reaction in sodium system. In small water leak, the leak propagation phenomena and the development of leak detecting system at initial stage of small water leak were studied, mainly. In this study, the corrosion phenomena on the target tube surface appeared by sodium-water reaction was analyzed through the small water leak experiments, and, also, the jet phenomena formed by N 2 gas injection through the leak nozzle under water medium was observed

  5. Small leak detection requirements for SNR-300 steam generator operation

    International Nuclear Information System (INIS)

    Dumm, K.

    1975-01-01

    The leak detection philosophy of the SNR-300 steam generators is described. Due to operational demands small leaks have already to be detectable at a stage where secondary tube damage has not yet occurred. The requirements on a leak detection instrument are developed and the instrument itself is described. (author)

  6. Double Shell Tank AY-102 Radioactive Waste Leak Investigation

    International Nuclear Information System (INIS)

    Washenfelder, Dennis J.

    2014-01-01

    PowerPoint. The objectives of this presentation are to: Describe Effort to Determine Whether Tank AY-102 Leaked; Review Probable Causes of the Tank AY-102 Leak; and, Discuss Influence of Leak on Hanford's Double-Shell Tank Integrity Program

  7. 1999 Leak Detection, Monitoring, and Mitigation Strategy Update

    International Nuclear Information System (INIS)

    OHL, P.C.

    1999-01-01

    This document is a complete revision of WHC-SD-WM-ES-378, Rev 1. This update includes recent developments in Leak Detection, Leak Monitoring, and Leak Mitigation technologies, as well as, recent developments in single-shell tank retrieval technologies. In addition, a single-shell tank retrieval release protection strategy is presented

  8. Special storage of leaking fuel at Paks NPP

    International Nuclear Information System (INIS)

    Biro, Janos; Szőke, L.; Burján, T.; Lukács, R.; Hózer, H.

    2015-01-01

    In this paper the activities related with spent, hermetic as well as leaking fuel handling and storage, including: Spent fuel pool; Transportation criteria for the spent fuel assemblies and Interim spent fuel dry storage; Short-term storage in the spent fuel pool; Identification of the leaking assemblies by the TS-device; Present conception of Identification, handling of the leaking FAs; Modified transport procedure for the leaking FAs; Calculation of solved activity inside the leaking fuel rod; Solved activity limit values for the leaking FAs; Long-term storage in the interim spent Fuel dry storage are presented. At the end authors’ concluded that: 1) The leaking FA can be transported to the interim dry storage together with the other spent fuel assemblies in the transport container. 2) The transport-documentation of the leaking FA has to contain: isotope inventory, calculated solved activity values of the failed FA and the quantity of failed fuel rods. 3) Performing three leakage tests of the identified leaking FA before the transportation in the 5FP. it is useful to decrease the solved activity concentration inside the leaking FA and give additional information about the extent of the leakage. 4) We can calculate simply the solved activity of the leaking FA. 5) The modified transport procedure will have to be authorized. 6) The radiological effects of the leaking FA are negligible relative to the natural background radiation

  9. Final evaluation of advanced and current leak detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.S.; Carlson, R.; Brewer, W.; Lanham, R.

    1989-01-01

    This report presents the results of a study to evaluate the adequacy of leak detection systems in light water reactors. The sources of numerous reported leaks and methods of detection have been documented. Research to advance the state of the art of acoustic leak detection is presented, and procedures for implementation are discussed

  10. Automated leak localization performance without detailed demand distribution data

    NARCIS (Netherlands)

    Moors, Janneke; Scholten, L.; van der Hoek, J.P.; den Besten, J.

    2018-01-01

    Automatic leak localization has been suggested to reduce the time and personnel efforts needed to localize
    (small) leaks. Yet, the available methods require a detailed demand distribution model for successful
    calibration and good leak localization performance. The main aim of this work was

  11. Water leaks in sodium-heated fast reactor boilers

    International Nuclear Information System (INIS)

    Hayes, D.J.

    1978-01-01

    Constraints on plant design which may result from considerations of leak behaviour and leak detection limits are briefly considered. The sodium-water interface and reactions, the behaviour of small leaks, hydrogen bubbles and detection methods, including galvanic cell methods, are included. (UK)

  12. 40 CFR 63.648 - Equipment leak standards.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Equipment leak standards. 63.648...) National Emission Standards for Hazardous Air Pollutants From Petroleum Refineries § 63.648 Equipment leak...) through (c)(10) and (e) through (i) of this section. (1) The instrument readings that define a leak for...

  13. 40 CFR 63.769 - Equipment leak standards.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Equipment leak standards. 63.769... § 63.769 Equipment leak standards. (a) This section applies to equipment subject to this subpart and... release to detect leaks, except under the following conditions. (i) The owner or operator has obtained...

  14. 40 CFR 63.1331 - Equipment leak provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Equipment leak provisions. 63.1331... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1331 Equipment leak... in pumps and agitator seals in light liquid service shall not be considered to be a leak. For...

  15. 10 CFR 39.35 - Leak testing of sealed sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Leak testing of sealed sources. 39.35 Section 39.35 Energy....35 Leak testing of sealed sources. (a) Testing and recordkeeping requirements. Each licensee who uses... record of leak test results in units of microcuries and retain the record for inspection by the...

  16. 40 CFR 63.1434 - Equipment leak provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Equipment leak provisions. 63.1434... Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production § 63.1434 Equipment leak provisions. (a) The owner or operator of each affected source shall comply with the HON equipment leak...

  17. 40 CFR 63.1410 - Equipment leak provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Equipment leak provisions. 63.1410... leak provisions. The owner or operator of each affected source shall comply with the requirements of 40 CFR part 63, subpart UU (national emission standards for equipment leaks (control level 2)) for all...

  18. 49 CFR 195.444 - CPM leak detection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false CPM leak detection. 195.444 Section 195.444... PIPELINE Operation and Maintenance § 195.444 CPM leak detection. Each computational pipeline monitoring (CPM) leak detection system installed on a hazardous liquid pipeline transporting liquid in single...

  19. 49 CFR 195.134 - CPM leak detection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false CPM leak detection. 195.134 Section 195.134... PIPELINE Design Requirements § 195.134 CPM leak detection. This section applies to each hazardous liquid... computational pipeline monitoring (CPM) leak detection system and each replaced component of an existing CPM...

  20. Small leak detection requirements for SNR-300 steam generator operation

    Energy Technology Data Exchange (ETDEWEB)

    Dumm, K

    1975-07-01

    The leak detection philosophy of the SNR-300 steam generators is described. Due to operational demands small leaks have already to be detectable at a stage where secondary tube damage has not yet occurred. The requirements on a leak detection instrument are developed and the instrument itself is described. (author)

  1. Surface proton transport of fully protonated poly(aspartic acid) thin films on quartz substrates

    Science.gov (United States)

    Nagao, Yuki; Kubo, Takahiro

    2014-12-01

    Thin film structure and the proton transport property of fully protonated poly(aspartic acid) (P-Asp100) have been investigated. An earlier study assessed partially protonated poly(aspartic acid), highly oriented thin film structure and enhancement of the internal proton transport. In this study of P-Asp100, IR p-polarized multiple-angle incidence resolution (P-MAIR) spectra were measured to investigate the thin film structure. The obtained thin films, with thicknesses of 120-670 nm, had no oriented structure. Relative humidity dependence of the resistance, proton conductivity, and normalized resistance were examined to ascertain the proton transport property of P-Asp100 thin films. The obtained data showed that the proton transport of P-Asp100 thin films might occur on the surface, not inside of the thin film. This phenomenon might be related with the proton transport of the biological system.

  2. Wall conditioning and leak localization in the advanced toroidal facility

    International Nuclear Information System (INIS)

    Langley, R.A.; Glowienka, J.C.; Mioduszewski, P.K.; Murakami, M.; Rayburn, T.F.; Simpkins, J.E.; Schwenterly, S.W.; Yarber, J.L.

    1989-01-01

    The Advanced Toroidal Facility (ATF) vacuum vessel and its internal components have been conditioned for plasma operation by baking, discharge cleaning with hydrogen and helium, and gettering with chromium and titanium. The plasma-facing surface of ATF consists mainly of stainless steel with some graphite; the outgassing area is dominated by the graphite because of its open porosity. Since this situation is somewhat different from that in other fusion plasma experiments, in which a single material dominates both the outgassing area and the plasma-facing area, different cleaning and conditioning techniques are required. The situation was aggravated by air leaks in the vacuum vessel, presumably resulting from baking and from vibration during plasma operation. The results of the various cleaning and conditioning techniques used are presented and compared on the basis of residual gas analysis and plasma performance. A technique for detecting leaks from the inside of the vacuum vessel is described; this technique was developed because access to the outside of the vessel is severely restricted by external components. 10 refs., 6 figs., 2 tabs

  3. Wall conditioning and leak localization in the Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    Langley, R.A.; Glowienka, J.C.; Mioduszewski, P.K.; Murakami, M.; Rayburn, T.F.; Simpkins, J.E.; Schwenterly, S.W.; Yarber, J.L.

    1990-01-01

    The Advanced Toroidal Facility (ATF) vacuum vessel and its internal components have been conditioned for plasma operation by baking, discharge cleaning with hydrogen and helium, and gettering with chromium and titanium. The plasma-facing surface of ATF consists mainly of stainless steel with some graphite; the outgassing area is dominated by the graphite because of its open porosity. Since this situation is somewhat different from that in other fusion plasma experiments, in which a single material dominates both the outgassing area and the plasma-facing area, different cleaning and conditioning techniques are required. The situation was aggravated by air leaks in the vacuum vessel, presumably resulting from baking and from vibration during plasma operation. The results of the various cleaning and conditioning techniques used are presented and compared on the basis of residual gas analysis and plasma performance. A technique for detecting leaks from the inside of the vacuum vessel is described. This technique was developed because access to the outside of the vessel is severely restricted by external components

  4. Exploring the entrance of proton pathways in cytochrome c oxidase from Paracoccus denitrificans: surface charge, buffer capacity and redox-dependent polarity changes at the internal surface.

    Science.gov (United States)

    Kirchberg, Kristina; Michel, Hartmut; Alexiev, Ulrike

    2013-03-01

    Cytochrome c oxidase (CcO), the terminal oxidase of cellular respiration, reduces molecular oxygen to water. The mechanism of proton pumping as well as the coupling of proton and electron transfer is still not understood in this redox-linked proton pump. Eleven residues at the aqueous-exposed surfaces of CcO from Paracoccus denitrificans have been exchanged to cysteines in a two-subunit base variant to yield single reactive cysteine variants. These variants are designed to provide unique labeling sites for probes to be used in spectroscopic experiments investigating the mechanism of proton pumping in CcO. To this end we have shown that all cysteine variants are enzymatically active. Cysteine positions at the negative (N-) side of the membrane are located close to the entrance of the D- and K-proton transfer pathways that connect the N-side with the catalytic oxygen reduction site. Labeling of the pH-indicator dye fluorescein to these sites allowed us to determine the surface potential at the cytoplasmic CcO surface, which corresponds to a surface charge density of -0.5 elementary charge/1000Å(2). In addition, acid-base titrations revealed values of CcO buffer capacity. Polarity measurements of the label environment at the N-side provided (i) site-specific values indicative of a hydrophilic and a more hydrophobic environment dependent on the label position, and (ii) information on a global change to a more apolar environment upon reduction of the enzyme. Thus, the redox state of the copper and heme centers inside the hydrophobic interior of CcO affect the properties at the cytoplasmic surface. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Leak Detection Modeling and Simulation for Oil Pipeline with Artificial Intelligence Method

    OpenAIRE

    Sukarno, Pudjo; Sidarto, Kuntjoro Adji; Trisnobudi, Amoranto; Setyoadi, Delint Ira; Rohani, Nancy; Darmadi, Darmadi

    2007-01-01

    Leak detection is always interesting research topic, where leak location and leak rate are two pipeline leaking parameters that should be determined accurately to overcome pipe leaking problems. In this research those two parameters are investigated by developing transmission pipeline model and the leak detection model which is developed using Artificial Neural Network. The mathematical approach needs actual leak data to train the leak detection model, however such data could not be obtained ...

  6. Intraoperative air leak measured after lobectomy is associated with postoperative duration of air leak.

    Science.gov (United States)

    Brunelli, Alessandro; Salati, Michele; Pompili, Cecilia; Gentili, Paolo; Sabbatini, Armando

    2017-11-01

    To verify the association between the air leak objectively measured intraoperatively (IAL) using the ventilator and the air leak duration after pulmonary lobectomy. Prospective analysis on 111 patients submitted to pulmonary lobectomy (33 by video-assisted thoracic surgery). After resection, objective assessment of air leak (in milliliter per minute) was performed before closure of the chest by measuring the difference between a fixed inspired and expired volume, using a tidal volume of 8 ml/kg, a respiratory rate of 10 and a positive-end expiratory pressure of 5 cmH2O. A multivariable analysis was performed for identifying factors associated with duration of postoperative air leak. Average IAL was 158 ml/min (range 0-1500 ml/min). The best cut-off (receiver-operating characteristics analysis) associated with air leak longer than 5 days was 500 ml/min. Nine patients had IAL >500 ml/min (8%). They had a longer duration of postoperative air leak compared with those with a lower IAL (mean values, 10.1 days, SD 8.8 vs 1.5 days, SD 4.9 P leak duration after multivariable regression: left side resection (P = 0.018), upper site resection (P = 0.031) and IAL >500 ml/min (P leak duration was generated: 1.7 + 2.4 × left side + 2.2 × upper site + 8.8 × IAL >500. The air leak measurement using the ventilator parameters after lung resection may assist in estimating the risk of postoperative prolonged air leak. An IAL > 500 ml/min may warrant the use of intraoperative preventative measures, particularly after video-assisted thoracic surgery lobectomy where a submersion test is often unreliable. © 2017 European Society of Cardiology and European Atherosclerosis Association. All rights reserved. For permissions please email: journals.permissions@oup.com.

  7. Application of acoustic leak detection technology for the detection and location of leaks in light water reactors

    International Nuclear Information System (INIS)

    Kupperman, D.S.; Prine, D.; Mathieson, T.

    1988-10-01

    This report presents the results of a study to evaluate the adequacy of leak detection systems in light water reactors. The sources of numerous reported leaks and methods of detection have been documented. Research to advance the state of the art of acoustic leak detection is presented, and procedures for implementation are discussed. 14 refs., 70 figs., 10 tabs

  8. Steam generator leak detection at Bruce A Unit 1

    International Nuclear Information System (INIS)

    Maynard, K.J.; McInnes, D.E.; Singh, V.P.

    1997-01-01

    A new steam generator leak detection system was recently developed and utilized at Bruce A. The equipment is based on standard helium leak detection, with the addition of moisture detection and several other capability improvements. All but 1% of the Unit 1 Boiler 03 tubesheet was inspected, using a sniffer probe which inspected tubes seven at a time and followed by individual tube inspections. The leak search period was completed in approximately 24 hours, following a prerequisite period of several days. No helium leak indications were found anywhere on the boiler. A single water leak indication was found, which was subsequently confirmed as a through-wall defect by eddy current inspection. (author)

  9. Fluid pipeline leak detection and location with miniature RF tags

    Science.gov (United States)

    McIntyre, Timothy J.

    2017-05-16

    Sensors locate troublesome leaks in pipes or conduits that carry a flowing medium. These sensors, through tailored physical and geometric properties, preferentially seek conduit leaks or breaches due to flow streaming. The sensors can be queried via transceivers outside the conduit or located and interrogated inside by submersible unmanned vehicle to identify and characterize the nature of a leak. The sensors can be functionalized with other capabilities for additional leak and pipeline characterization if needed. Sensors can be recovered from a conduit flow stream and reused for future leak detection activities.

  10. Experiences in integrated leak rate measurements

    International Nuclear Information System (INIS)

    Shirk, R.E.

    1982-01-01

    During a hypothetical design basis accident for nuclear power plants, the reactor containment system is relied upon to maintain radioactive exposure limits below acceptable limits. Integrated leak rate testing is a means of verifying that the leakage of radioactivity material from the reactor containment will be below allowable limits. Leakage rate computations are based on the ideal gas law. The absolute method of leakage rate testing utilizing mass point method of data analysis is recommended. Integrated leak rate testing data is obtained from pressure, drybulb temperature, dewpoint temperature, and flow measuring systems. Test data does not support the usual leakage (flow) - pressure square root relationship. The major source of potential leakage from the reactor containment is reactor containment isolation valves

  11. Monju secondary heat transport system sodium leak

    International Nuclear Information System (INIS)

    Suzuki, Takeo; Hiroi, Hiroshi; Usami, Shin; Iwata, Koji.

    1996-01-01

    On December 8, 1995, the sodium leakage from the secondary heat transport system (SHTS) occurred in the piping room of the reactor auxiliary building in Monju. The secondary sodium leaked through a temperature sensor, due to the breakaway of the tip of the well tube of the sensor installed near the outlet of the intermediate heat exchanger (IHX) in the C loop of SHTS. The reactor core remained cooled and thus, from the viewpoint of radiological hazards, the safety of the reactor was secured. There were no adverse effects for operating personnel or the surrounding environment. The cause of the well tube failure is considered to result from high cycle fatigue due to flow induced vibrations. Delay in draining the sodium from the leaking loop increased the consequential effects from sodium combustion products. (author)

  12. Development of leak detector by radiation. 2

    International Nuclear Information System (INIS)

    Suzuki, Takashi; Okano, Yasuhiro; Chisaka, Haruo

    1997-01-01

    Leak detector by radiation has been developed by cooperative research between Water Authority and us. In his fiscal year, the most suitable arrangement of detector system was simulated by Monte Carlo method. The first, the experimental values were compared with the results of simulation. The second, calculation was carried out by changing the quality of reflective materials and distance between radiation source and detector. The simulation results were agreed with the experimental results. On the basis of the rate of presence of leak, the most suitable arrangement of detector system was obtained under the conditions that both radiation source and detector covered with graphite or iron of 5 cm thickness and separated each other 3 cm apart. However, by comparing FOM (figure of merit), the suitable arrangement was that radiation source and detector adjoined each other and covered by graphite or iron of 20 cm thickness. (S.Y.)

  13. Heavy water leak detection using diffusion sampler

    International Nuclear Information System (INIS)

    Joshi, M.L.; Hussain, S.A.

    1990-01-01

    In the Pressurrised Heavy Water Reactors (PHWRs) detection of the sources of heavy water leaks is importent both for the purpose of radiation hazard control as well as for the reduction of escape/loss of heavy water which, is an expensive nuclear material. This paper describes an application of tritium diffusion sampler for heavy water leak detection. The diffusion sampler comprises an usual tritium counting glass vial with a special orifice. The counting vial has water vapour, deficient in HTO concentration. The HTO present outside diffuses in the vial through the orifice, gets exchanged with water of the wet filter paper kept at the bottom and the moisture in the vial atmosphere which has HTO concentration lower than that outside. This results in continuation of net movement of HTO in the vial. The exchanged tritium is counted in liquid scintillation spectrometer. The method has a sensitivity of 10000 dpm/DAC-h. (author). 2 figs., 2 ta bs

  14. Method for mapping a natural gas leak

    Science.gov (United States)

    Reichardt, Thomas A [Livermore, CA; Luong, Amy Khai [Dublin, CA; Kulp, Thomas J [Livermore, CA; Devdas, Sanjay [Albany, CA

    2009-02-03

    A system is described that is suitable for use in determining the location of leaks of gases having a background concentration. The system is a point-wise backscatter absorption gas measurement system that measures absorption and distance to each point of an image. The absorption measurement provides an indication of the total amount of a gas of interest, and the distance provides an estimate of the background concentration of gas. The distance is measured from the time-of-flight of laser pulse that is generated along with the absorption measurement light. The measurements are formatted into an image of the presence of gas in excess of the background. Alternatively, an image of the scene is superimposed on the image of the gas to aid in locating leaks. By further modeling excess gas as a plume having a known concentration profile, the present system provides an estimate of the maximum concentration of the gas of interest.

  15. Subsea leak detection systems - recommended practice

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Kristin Nergaard

    2010-07-01

    It is known in the industry that occasional leakages occur in subsea production systems. In spite of efforts to apply subsea leak detectors, the experience is that most leakages are either detected by ROV during routine inspections or interventions or as oil slicks on the surface . Operators and authority awareness towards the environmental impact of oil and gas production is increasing. The regulatory bodies in Norway, EU and USA specify requirements for detection of acute pollution. This paper presents the development of a Recommended Practice (RP) sponsored by OLF (The Norwegian Oil Industry Association). The JIP includes several major oil and gas operators. The objective of the RP is to serve as a technical and practical reference in the field of subsea leak detection. (Author)

  16. Fast leak in channel H9

    International Nuclear Information System (INIS)

    Bauer, E.

    1987-01-01

    The loss of seal of the H9 channel in vacuum, freeing the entire cross section of the front part, leads to a fast leak that progresses rapidly. The effect of depressurizing the reflector can leads to shutdown of the shutdown rod pumps. The source changer associated with the channel fills completely before the valve closes. All of the leak water remains contained within the source changer containment. After the valves open, cooling of the fuel element is handled by natural convection, requiring a reversal of the flow between the plates. This changeover, which takes place at a relatively low pressure level, could lead to local boiling in the fuel element. Consequently, irreversible transformations cannot be excluded as possibilities for the fuel element and even for the control rod. Subsequently, the can is refilled with heavy water with establishment of the usual pressure levels

  17. Probabilistic pipe fracture evaluations for leak-rate-detection applications

    International Nuclear Information System (INIS)

    Rahman, S.; Ghadiali, N.; Paul, D.; Wilkowski, G.

    1995-04-01

    Regulatory Guide 1.45, open-quotes Reactor Coolant Pressure Boundary Leakage Detection Systems,close quotes was published by the U.S. Nuclear Regulatory Commission (NRC) in May 1973, and provides guidance on leak detection methods and system requirements for Light Water Reactors. Additionally, leak detection limits are specified in plant Technical Specifications and are different for Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). These leak detection limits are also used in leak-before-break evaluations performed in accordance with Draft Standard Review Plan, Section 3.6.3, open-quotes Leak Before Break Evaluation Proceduresclose quotes where a margin of 10 on the leak detection limit is used in determining the crack size considered in subsequent fracture analyses. This study was requested by the NRC to: (1) evaluate the conditional failure probability for BWR and PWR piping for pipes that were leaking at the allowable leak detection limit, and (2) evaluate the margin of 10 to determine if it was unnecessarily large. A probabilistic approach was undertaken to conduct fracture evaluations of circumferentially cracked pipes for leak-rate-detection applications. Sixteen nuclear piping systems in BWR and PWR plants were analyzed to evaluate conditional failure probability and effects of crack-morphology variability on the current margins used in leak rate detection for leak-before-break

  18. He leak testing of Indus-2 dipole vacuum chambers

    International Nuclear Information System (INIS)

    Sindal, B.K.; Bhavsar, S.T.; Shukla, S.K.

    2003-01-01

    Full text: Centre for Advanced Technology is developing its second synchrotron radiation source INDUS-2 which is a 2.5 GeV electron storage ring. Dipole vacuum chambers are the vital components of Indus-2 vacuum system. Each of these chambers is approx. 3.6 m long and 0.67 m wide with 24 nos. of ports of various sizes. The dipole chambers were made by machining two halves and they are then lip welded together. The dipole chamber has approx. 14 m of total weld length and it was leak tested for leak tightness of the order of 10 -10 mbar 1/s. Helium mass spectrometer leak detector (HMSLD) was utilized for the leak testing. Subsequently the leaks of various orders in welding joints were repaired and leak tightness achieved. This paper describes the experiences during leak testing of 20 nos. of aluminum dipole chambers for INDUS-2

  19. Fuel leak testing performance at NPP Jaslovske Bohunice

    International Nuclear Information System (INIS)

    Slugen, V.; Krnac, S.; Smiesko, I.

    1995-01-01

    The NPP Bohunice VVER-440 fuel leak testing experience are relatively extensive in comparison with other VVER-440 users. As the first Europe NPP was adapted Siemens (KWU) in core-sipping equipment to VVER-440 units and since this time were have done these tests also for NPP Paks (Hungary) and NPP Dukovany (Czech Republic). The occurrence of leaking fuel assemblies in NPP is in the last 5 years relatively stabilised and low. A significant difference can be observed between type V-230 (31 leaks) and type V-213 (1 leak). None of of the indicated leaking fuel assemblies has been investigated in the hot cell. Therefore cannot be confirm the effective causes of leak occurrence. Nevertheless, the fuel failure rate and the performance of leak testing in NPP Bohunice are comparable to the world standard at PWR's. 1 tab., 2 figs., 3 refs

  20. Fuel leak testing performance at NPP Jaslovske Bohunice

    Energy Technology Data Exchange (ETDEWEB)

    Slugen, V; Krnac, S [Slovak Technical Univ., Bratislava (Slovakia); Smiesko, I [Nuclear Powr Plant EBO, Jaslovske Bohuce (Slovakia)

    1996-12-31

    The NPP Bohunice VVER-440 fuel leak testing experience are relatively extensive in comparison with other VVER-440 users. As the first Europe NPP was adapted Siemens (KWU) in core-sipping equipment to VVER-440 units and since this time were have done these tests also for NPP Paks (Hungary) and NPP Dukovany (Czech Republic). The occurrence of leaking fuel assemblies in NPP is in the last 5 years relatively stabilised and low. A significant difference can be observed between type V-230 (31 leaks) and type V-213 (1 leak). None of of the indicated leaking fuel assemblies has been investigated in the hot cell. Therefore cannot be confirm the effective causes of leak occurrence. Nevertheless, the fuel failure rate and the performance of leak testing in NPP Bohunice are comparable to the world standard at PWR`s. 1 tab., 2 figs., 3 refs.

  1. Stimulated leaks found with SmartBall tool

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2011-05-15

    Pure Technologies has developed a SmartBall leak detection tool which can be used in oil and gas pipelines. This tool contains acoustic sensors which listen for leaks and other problems in pipelines. Pig tracking units are used to track the tool along with receivers positioned on the pipe. With these technologies, SmartBall is able to detect small leaks that conventional methods would not detect and to assess their location accurately. Two runs on a Petrobras pipeline in Brazil highlighted the effectiveness of this technology, detecting three simulated leaks as small as 240mL/min. In addition, this system can give an estimation of the leak rate and traverse non piggable pipelines. Software is then used to analyze data and generate a report giving the size and location of the leaks identified. SmartBall is a technology capable of detecting small leaks and locating them in all sorts of oil and gas pipelines.

  2. Feedback regarding leaks in pipe work

    International Nuclear Information System (INIS)

    Guerville, C.; Boudouin, E.

    2011-01-01

    Contaminated effluent from nuclear medicine departments is stored in decay tanks before being discharged via the sewage system. Generally speaking, these tanks are located outside hospital wards, within the hospital's maintenance rooms. Pipes leading from the evacuation points (e.g. toilets in isolation wards) to the tanks may nonetheless pass through various other parts of the hospital premises (wards, corridors, offices, etc.). Should a leak occur in any of these pipes, this may impact on the public, workers or the environment. (author)

  3. Natural gas pipeline leaks across Washington, DC.

    Science.gov (United States)

    Jackson, Robert B; Down, Adrian; Phillips, Nathan G; Ackley, Robert C; Cook, Charles W; Plata, Desiree L; Zhao, Kaiguang

    2014-01-01

    Pipeline safety in the United States has increased in recent decades, but incidents involving natural gas pipelines still cause an average of 17 fatalities and $133 M in property damage annually. Natural gas leaks are also the largest anthropogenic source of the greenhouse gas methane (CH4) in the U.S. To reduce pipeline leakage and increase consumer safety, we deployed a Picarro G2301 Cavity Ring-Down Spectrometer in a car, mapping 5893 natural gas leaks (2.5 to 88.6 ppm CH4) across 1500 road miles of Washington, DC. The δ(13)C-isotopic signatures of the methane (-38.2‰ ± 3.9‰ s.d.) and ethane (-36.5 ± 1.1 s.d.) and the CH4:C2H6 ratios (25.5 ± 8.9 s.d.) closely matched the pipeline gas (-39.0‰ and -36.2‰ for methane and ethane; 19.0 for CH4/C2H6). Emissions from four street leaks ranged from 9200 to 38,200 L CH4 day(-1) each, comparable to natural gas used by 1.7 to 7.0 homes, respectively. At 19 tested locations, 12 potentially explosive (Grade 1) methane concentrations of 50,000 to 500,000 ppm were detected in manholes. Financial incentives and targeted programs among companies, public utility commissions, and scientists to reduce leaks and replace old cast-iron pipes will improve consumer safety and air quality, save money, and lower greenhouse gas emissions.

  4. Anastomotic leak detection by electrolyte electrical resistance.

    Science.gov (United States)

    DeArmond, Daniel T; Cline, Adam M; Johnson, Scott B

    2010-08-01

    To characterize a new method of postoperative gastrointestinal leak detection based on electrical resistance changes due to extravasated electrolyte contrast. Postoperative gastrointestinal leak results in increased patient morbidity, mortality, and hospital costs that can be mitigated by early diagnosis. A sensitive and specific diagnostic test that could be performed at the bedside has the potential to shorten the time to diagnosis and thereby improve the quality of treatment. Anaesthetized rats underwent celiotomy and creation of a 5-mm gastrotomy. In experimental animals, electrical resistance changes were measured with a direct current ohmmeter after the introduction of 5 cc of 23.4% NaCl electrolyte solution via gavage and measured with a more sensitive alternating current ohmmeter after the gavage of 1-5 cc of 0.9% NaCl. Comparison was made to negative controls and statistical analysis was performed. Leakage from the gastrotomy induced by as little as 1 cc of gavage-delivered 0.9% NaCl contrast solution was detectable as a statistically significant drop in electrical resistance when compared to results from negative controls. Electrical resistance change associated with electrolyte-gated leak detection is highly sensitive and specific and has the potential to be rapidly translated into clinical settings.

  5. Color Changing Material for Hydrogen Leak Detection

    Science.gov (United States)

    Victor, Megan E.

    2014-01-01

    Kennedy Space Center scientists developed a hydrogen leak sensor utilizing a combination of chemochromic pigment and polymer that can be molded or fiber spun into rigid or flexible shapes such as tape. The sensor turns a dark color when exposed to hydrogen gas. This sensor has proven to be very effective for pinpointing the exact location of leaks in hydrogen gas lines and fittings at launch pads. Kennedy Space Center exclusively licensed this technology to the University of Central Florida (UCF), who also holds patents that are complimentary to KSC's. UCF has bundled the patents and exclusively licensed the portfolio to HySense Technology LLC, a startup company founded by a UCF professor who supports the UCF Florida Solar Energy Center (FSEC). HySense has fully developed its product (known as Intellipigment"TM"), and currently has five commercial customers. The company recently won the $100,000 first-place award at the CAT5 innovation competition at the Innovation Concourse of the Southeast: Safety & Manufacturing event in Orlando, FL. Commercial production and sales of this technology by HySense Technology will make this leak sensor widely available for use by NASA, DoD, and industries that utilize hydrogen gas.

  6. FFTF integrated leak rate computer system

    International Nuclear Information System (INIS)

    Hubbard, J.A.

    1987-01-01

    The Fast Flux Test Facility (FFTF) is a liquid-metal-cooled test reactor located on the Hanford site. The FFTF is the only reactor of this type designed and operated to meet the licensing requirements of the Nuclear Regulatory Commission. Unique characteristics of the FFTF that present special challenges related to leak rate testing include thin wall containment vessel construction, cover gas systems that penetrate containment, and a low-pressure design basis accident. The successful completion of the third FFTF integrated leak rate test 5 days ahead of schedule and 10% under budget was a major achievement for the Westinghouse Hanford Company. The success of this operational safety test was due in large part to a special network (LAN) of three IBM PC/XT computers, which monitored the sensor data, calculated the containment vessel leak rate, and displayed test results. The equipment configuration allowed continuous monitoring of the progress of the test independent of the data acquisition and analysis functions, and it also provided overall improved system reliability by permitting immediate switching to backup computers in the event of equipment failure

  7. Leak rate test of containment personnel lock

    International Nuclear Information System (INIS)

    Julien, J.T.; Peters, S.W.

    1988-01-01

    As part of the US NRC Containment Integrity Program, a leak rate test was performed on a full size personnel airlock for a nuclear containment building. The airlock was subjected to conditions simulating severe accident conditions. The objective of the test was to characterize the performance of airlock door seals when subjected to conditions that exceeded design. The seals tested were a double dog-ear configuration and made from EPDM E603. The data obtained from this test will be used by SNL as a benchmark for development of analytical methods. In addition to leak rate information, strain, temperature, displacements, and pressure data were measured and recorded from over 330 transducers. The test lasted approximately 60 hours. Data were recorded at regular intervals and during heating, pressurization and depressurization. The inner airlock door and bulkhead were exposed to a maximum air temperature of 850 F and a maximum air pressure of 300 psig. The airlock was originally designed for 340 F and 60 psig. Two heating and pressurization cycles were planned; one to heat to 400 F and pressurize to 300 psig, and the second to heat to 800 F and pressurize to 300 psig. No significant leakage was recorded during these two cycles. A third cycle was added to the test program. The air temperature was increased to 850 F and held at this temperature for approximately 10 hours. The inner door seal failed quickly at a pressure of 150.5 psig. The maximum leak rate was 706 SCFM

  8. Confidence Leak in Perceptual Decision Making.

    Science.gov (United States)

    Rahnev, Dobromir; Koizumi, Ai; McCurdy, Li Yan; D'Esposito, Mark; Lau, Hakwan

    2015-11-01

    People live in a continuous environment in which the visual scene changes on a slow timescale. It has been shown that to exploit such environmental stability, the brain creates a continuity field in which objects seen seconds ago influence the perception of current objects. What is unknown is whether a similar mechanism exists at the level of metacognitive representations. In three experiments, we demonstrated a robust intertask confidence leak-that is, confidence in one's response on a given task or trial influencing confidence on the following task or trial. This confidence leak could not be explained by response priming or attentional fluctuations. Better ability to modulate confidence leak predicted higher capacity for metacognition as well as greater gray matter volume in the prefrontal cortex. A model based on normative principles from Bayesian inference explained the results by postulating that observers subjectively estimate the perceptual signal strength in a stable environment. These results point to the existence of a novel metacognitive mechanism mediated by regions in the prefrontal cortex. © The Author(s) 2015.

  9. Waste Transfer Leaks Control Decision Record

    International Nuclear Information System (INIS)

    RYAN, G.W.

    2000-01-01

    Control decision meetings for Waste Transfer Leaks were held on April 24,25,26, and 27, 2000. The agenda for the control decision meetings is included in Appendix A, and attendee lists are included in Appendix B. The purpose of the control decision meetings was to review and revise previously selected controls for the prevention or mitigation of waste transfer leak accidents. Re-evaluation of the controls is warranted due to revisions in the hazard and accident analysis for these Tank Farm events. In particular, calculated radiological consequences are significantly reduced from those currently reported in the Final Safety Analysis Report (FSAR). Revised hazard and accident analysis and a revised control recommendation will be reflected in an Authorization Basis Amendment to be submitted at the Department of Energy, Office of River Protection's (ORP's) request by June 30, 2000 to satisfy ORP Performance Incentive (PI) 2.1.1, Revision 1, ''Authorization Basis Management Process Efficiency Improvement''. The scope of the control decision meetings was to address all waste transfer leak-related hazardous conditions identified in the Tank Farm hazard analysis database, excluding those associated with the use of the Replacement Cross-Site Transfer System (RCSTS) slurry line and sluicing of Tank 241-C-106, which is addressed in FSAR Addendum 1. The scope of this control decision process does include future waste feed delivery waste transfer operations

  10. Leak monitoring method for a reactor container

    International Nuclear Information System (INIS)

    Uehara, Toshio.

    1987-01-01

    Purpose: To confirm leakages from a container upon nuclear reactor operation. Method: Leakages from a nuclear reactor container has been prevented by lowering the inner pressure of the container relative to the external pressure. In the conventional method of calculating the leakage by applying an inner pressure to the container and measuring the pressure change, etc. after the elapse of a pre-determined time, the measurement has to be conducted at periodical inspection when the nuclear reactor is shut-down. In view of the above, the leak test is conducted in the present invention by applying a slight inner pressure to the inside of the reactor container by supplying gases from a gas supply system and detecting the flow rate of the gases in the gas supply system while maintaining the slight inner pressure constant by controlling the supply and discharge of the gases. By applying such a inner pressure as causing no effect to the reactor operation, it is possible to monitor the leaks during operation and to detect the flow rate value surely and continuously if the leak is resulted. (Kamimura, M.)

  11. Airborne pipeline leak detection: UV or IR?

    Science.gov (United States)

    Babin, François; Gravel, Jean-François; Allard, Martin

    2016-05-01

    This paper presents a study of different approaches to the measurement of the above ground vapor plume created by the spill caused by a small 0.1 l/min (or less) leak in an underground liquid petroleum pipeline. The scenarios are those for the measurement from an airborne platform. The usual approach is that of IR absorption, but in the case of liquid petroleum products, there are drawbacks that will be discussed, especially when using alkanes to detect a leak. The optical measurements studied include UV enhanced Raman lidar, UV fluorescence lidar and IR absorption path integrated lidars. The breadboards used for testing the different approaches will be described along with the set-ups for leak simulation. Although IR absorption would intuitively be the most sensitive, it is shown that UV-Raman could be an alternative. When using the very broad alkane signature in the IR, the varying ground spectral reflectance are a problem. It is also determined that integrated path measurements are preferred, the UV enhanced Raman measurements showing that the vapor plume stays very close to the ground.

  12. Epidural block and neostigmine cause anastomosis leak

    Directory of Open Access Journals (Sweden)

    Ataro G

    2016-05-01

    Full Text Available Getu Ataro Department of Anesthesia, Jimma University, Jimma, EthiopiaI read the article by Phillips entitled, “Reducing gastrointestinal anastomotic leak rates: review of challenges and solutions”, published in the journal of Open Access Surgery with enthusiasm and found it crucial for perioperative management of patients with gastrointestinal (GI surgery, particularly anastomosis. I appreciate the author’s exhaustive search of literature and discussion with some limitation on review basics like methodology, which may affect the reliability of the review findings. The effects of risk factors for anastomosis leak, such as malnutrition, smoking, steroid use, bowel preparation, chemotherapy, duration of surgery, use of pressors, intravenous fluid administration, blood transfusion, and surgical anastomotic technique, were well discussed.1 However, from anesthesia perspective, there are some other well-studied risk factors that can affect healing of anastomosis wound and cause anastomosis leak. Among others, the effect of neostigmine and epidural block has been reported in many studies since half a century ago. View the original paper by Phillips

  13. Estimation of Leak Flow Rate during Post-LOCA Using Cascaded Fuzzy Neural Networks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Yeong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of)

    2016-10-15

    In this study, important parameters such as the break position, size, and leak flow rate of loss of coolant accidents (LOCAs), provide operators with essential information for recovering the cooling capability of the nuclear reactor core, for preventing the reactor core from melting down, and for managing severe accidents effectively. Leak flow rate should consist of break size, differential pressure, temperature, and so on (where differential pressure means difference between internal and external reactor vessel pressure). The leak flow rate is strongly dependent on the break size and the differential pressure, but the break size is not measured and the integrity of pressure sensors is not assured in severe circumstances. In this paper, a cascaded fuzzy neural network (CFNN) model is appropriately proposed to estimate the leak flow rate out of break, which has a direct impact on the important times (time approaching the core exit temperature that exceeds 1200 .deg. F, core uncover time, reactor vessel failure time, etc.). The CFNN is a data-based model, it requires data to develop and verify itself. Because few actual severe accident data exist, it is essential to obtain the data required in the proposed model using numerical simulations. In this study, a CFNN model was developed to predict the leak flow rate before proceeding to severe LOCAs. The simulations showed that the developed CFNN model accurately predicted the leak flow rate with less error than 0.5%. The CFNN model is much better than FNN model under the same conditions, such as the same fuzzy rules. At the result of comparison, the RMS errors of the CFNN model were reduced by approximately 82 ~ 97% of those of the FNN model.

  14. Momentum starts to build for enactment of leak detector standards

    International Nuclear Information System (INIS)

    Prowler, S.

    1992-01-01

    This paper reports that after years of being bandied about within the LP-gas industry but never quite moving beyond the discussion stage, the subject of residential fuel gas leak detectors has finally elicited sufficient attention and group involvement to command priority status and a government agency report. The question of whether or not a propane consumer should spend his or her money on one or more of these devices has sparked deeper discussions regarding internal placement, response sensitivity, maintenance, and a host of other issues. Although some technical questions remain unresolved, it is noteworthy for now that the need to establish a suitable installation standard has been officially recognized by the Consumer Product Safety Commission (CPSC) and the National Fire Protection Association (NFPA) - two prominent entities that exert considerable influence upon the LP-gas industry

  15. The detection of leaks on sodium pipes in a 'leak before break' approach

    International Nuclear Information System (INIS)

    Antonakas, D.

    1989-01-01

    The operation of circuits containing liquid sodium requires, given the chemical affinity of this fluid for air and water, a reliable detection of possible leaks. This system of detection should alert the operators to the occurrence of a leak in sufficient time to limit the potential consequences of a discharge of sodium in the building, leading to a severe sodium fire or at least to an extended corrosion of the pipe system. From a design point of view, the most likely event leading to this situation can be the consequence. of an initial undetected defect which develops under the effect of thermo-mechanical loadings, produces a sodium. leak below the dejection threshold remains undetectable white progressing and finally leads to a guillotine-type rupture when an incidental loading is superimposed to the normal one. The 'leak before break' approach which is now currently introduced in design considerations consists of insuring the detection of incipient leaks corresponding to through-the-wall cracks well below instability of the pipe. Under this short statement, lies a considerable and still necessary effort of research broadly presented in the present paper

  16. Proton diffraction

    International Nuclear Information System (INIS)

    Den Besten, J.L.; Jamieson, D.N.; Allen, L.J.

    1998-01-01

    The Lindhard theory on ion channeling in crystals has been widely accepted throughout ion beam analysis for use in simulating such experiments. The simulations use a Monte Carlo method developed by Barret, which utilises the classical 'billiard ball' theory of ions 'bouncing' between planes or tubes of atoms in the crystal. This theory is not valid for 'thin' crystals where the planes or strings of atoms can no longer be assumed to be of infinite proportions. We propose that a theory similar to that used for high energy electron diffraction can be applied to MeV ions, especially protons, in thin crystals to simulate the intensities of transmission channeling and of RBS spectra. The diffraction theory is based on a Bloch wave solution of the Schroedinger equation for an ion passing through the periodic crystal potential. The widely used universal potential for proton-nucleus scattering is used to construct the crystal potential. Absorption due to thermal diffuse scattering is included. Experimental parameters such as convergence angle, beam tilt and scanning directions are considered in our calculations. Comparison between theory and experiment is encouraging and suggests that further work is justified. (authors)

  17. Surface proton transport of fully protonated poly(aspartic acid) thin films on quartz substrates

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Yuki, E-mail: ynagao@jaist.ac.jp; Kubo, Takahiro

    2014-12-30

    Graphical abstract: - Highlights: • Proton transport of fully protonated poly(aspartic acid) thin film was investigated. • The thin film structure differed greatly from the partially protonated one. • Proton transport occurs on the surface, not inside of the thin film. • This result contributes to biological transport systems such as bacteriorhodopsin. - Abstract: Thin film structure and the proton transport property of fully protonated poly(aspartic acid) (P-Asp100) have been investigated. An earlier study assessed partially protonated poly(aspartic acid), highly oriented thin film structure and enhancement of the internal proton transport. In this study of P-Asp100, IR p-polarized multiple-angle incidence resolution (P-MAIR) spectra were measured to investigate the thin film structure. The obtained thin films, with thicknesses of 120–670 nm, had no oriented structure. Relative humidity dependence of the resistance, proton conductivity, and normalized resistance were examined to ascertain the proton transport property of P-Asp100 thin films. The obtained data showed that the proton transport of P-Asp100 thin films might occur on the surface, not inside of the thin film. This phenomenon might be related with the proton transport of the biological system.

  18. Surface proton transport of fully protonated poly(aspartic acid) thin films on quartz substrates

    International Nuclear Information System (INIS)

    Nagao, Yuki; Kubo, Takahiro

    2014-01-01

    Graphical abstract: - Highlights: • Proton transport of fully protonated poly(aspartic acid) thin film was investigated. • The thin film structure differed greatly from the partially protonated one. • Proton transport occurs on the surface, not inside of the thin film. • This result contributes to biological transport systems such as bacteriorhodopsin. - Abstract: Thin film structure and the proton transport property of fully protonated poly(aspartic acid) (P-Asp100) have been investigated. An earlier study assessed partially protonated poly(aspartic acid), highly oriented thin film structure and enhancement of the internal proton transport. In this study of P-Asp100, IR p-polarized multiple-angle incidence resolution (P-MAIR) spectra were measured to investigate the thin film structure. The obtained thin films, with thicknesses of 120–670 nm, had no oriented structure. Relative humidity dependence of the resistance, proton conductivity, and normalized resistance were examined to ascertain the proton transport property of P-Asp100 thin films. The obtained data showed that the proton transport of P-Asp100 thin films might occur on the surface, not inside of the thin film. This phenomenon might be related with the proton transport of the biological system

  19. Sodium leak at Monju (II): Sodium leak, burning and aerosol behavior

    International Nuclear Information System (INIS)

    Funada, T.; Yamagishi, Y.

    1996-01-01

    The amount of leaked sodium was estimated as approximately 640 kg during the 220 minute leak. The ventilation duct and the walkway grating under the leak site were severely damaged by Na-Fe-O reaction, but the floor liner and the concrete wall were not. A total 100 kg of sodium aerosol was deposited in the reactor auxiliary building and 230 kg was released to the atmosphere. The sodium concentration at the site boundary was calculated as 0.05 mg/m 3 , NaOH equivalent, which was low in comparison with the permitted level of 2 mg/m 3 . The tritium quantity released was estimated as 4.4 x 10 7 Bq, which was about 0.03% of the average released value per month for a LWR. (author)

  20. Evaluation of advanced and current leak detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.S.

    1988-01-01

    U.S. Nuclear Regulatory Commission Guide 1.45 recommends the use of at least three different detection methods in reactors to detect leakage. Monitoring of both sump-flow and airborne particulate radioactivity is mandatory. A third method can involve either monitoring of condensate flow rate from air coolers or monitoring of airborne gaseous radioactivity. Although the methods currently used for leak detection reflect the state of the art, other techniques may be developed and used. Since the recommendations of Regulatory Guide 1.45 are not mandatory, Licensee Event Report Compilations have been reviewed to help establish actual capabilities for leak detection. The review of event reports, which had previously covered the period of June 1985 to August 1986 has been extended, and now covers events to June 1987. The total number of significant events is now 83. These reports have provided documented, sometimes detailed, summaries of reactor leaks. They have helped establish the capabilities of existing systems to detect and locate leaks. Differences between PWRs and BWRs with regard to leak detection have now been analyzed. With regard to detection methods, the greatest differences between reactor types are as follows: (a) The sump pump is reported as the detection method more frequently in BWRs than in PWRs (64% vs. 35%). (b) The radiation monitor is reported as the detection method (excluding false alarms) more frequently in PWRs. Current efforts at Argonne National Laboratory (ANL) to evaluate advanced acoustic leak detection methods are directed toward the generation and analysis of acoustic data from large (0.5 to 10 gal/min) leaks and modification of the software of the GARD/ANL advanced acoustic leak detection system. In order to reach the goal of 10 gal/min leaks, the Steam Generator Test Facility at ANL has been modified to carry out the leak testing. Tests were carried out with water at 525 deg. F and 1100 psi leaking through a fatigue crack in a 4-in

  1. The experiment and analysis on small leak phenomena

    International Nuclear Information System (INIS)

    Jeong, Kyung Chai; Hwang, S. T.; Kim, B. H.; Jeong, J. Y.

    2000-07-01

    The liquid sodium which is used as a coolant in LMFBR, may give rise to a serious trouble in the safety aspect of steam generator. The defects in a heat transfer tube, such as pin-hole or tube welding defect, will result in a leakage of high pressure steam into the sodium side and production of hydrogen gas and corrosive sodium compounds which can cause significant damage to the tube wall of steam generator by using exothermic reaction. In significant damage to the tube wall of steam generator by using exothermic reaction. In this case, initial leak size will be enlarged with time and the leak rate developed to large leak through the micro, small, intermediate leaks. Therefore, the analysis of sodium-water reaction phenomena on the micro and small water leaks in the heat transfer tube is very important in the initial leak stage in the aspects of the protection of leak progress and safety evaluation of steam generator. In this study, firstly, the micro and small leaks phenomena, such as reopen size, shape, and time of leak path, self-wastage, corrosion of tube materials, was analyzed from the literature survey and water leakage experiments using the leak specimen. In small water leak experiments, the leak path was plugged by the sodium-water reaction products at the leak path of a specimen, and re-open phenomena were not observed in initial experiments. Other leak experiments, reopen phenomena of self-plugged leak path was observed. Re-open mechanism of sealed path could be explained by the thermal transient and vibration of heat transfer tube. As a result, perfect reopen time of self plugged leak path was observed to be about 130 minutes after water leak initiation. Reopen shape of a specimen was appeared with double layer of circular type, and reopen size of this specimen surface was about 2 mm diameter on sodium side. Also, the corrosion of a specimen initiated from sodium side, the segregation phenomena of Cr in the specimen was found much more than those of

  2. Simple catalytic cell for restoring He leak detector sensitivity on vacuum systems with high D2 backgrounds

    International Nuclear Information System (INIS)

    Busath, J.; Chiu, H.K.

    1998-12-01

    The DIII-D National Fusion Facility at General Atomics focuses on plasma physics and fusion energy science. The DIII-D tokamak is a 35 m 3 toroidal vacuum vessel with over 200 ports for diagnostic instrumentation, cryogenics, microwave heating, and four large neutral beam injectors. Maintaining vacuum in the 10 -8 Torr range is crucial for producing high performance plasma discharges. He leak checking the DIII-D tokamak and the neutral beamlines has historically been difficult. D 2 is used as the fuel gas in most plasma discharges and neutral beams. After plasma operations, D 2 out-gassing from the torus walls and internal beamline components can exceed 10 -4 std cc/s. The mass of the D 2 molecule (4.028 u) is indistinguishable from that of the He atom (4.003 u) to a standard mass spectrometer leak detector. High levels of D 2 reduce leak detector sensitivity and effectively mask the He trace gas signal rendering normal leak checking techniques ineffective. A simple apparatus was developed at GA to address these problems. It consists of a palladium based catalyst cell and associated valves and piping placed in series with the leak detector. This reduces the D 2 throughput by a factor greater than 10,000, restoring leak detector sensitivity. This paper will briefly discuss the development of the cell, the physical processes involved, the tests performed to quantify and optimize the processes, and the operational results at DIII-D

  3. Fabrication of ultra-sensitive leak detection standards

    International Nuclear Information System (INIS)

    Winkelman, C.R.

    1980-01-01

    The primary difficulty with flow rate measurements below 10 -10 standard cubic centimeters per second (std. cc/sec) is that there are no commercially available standards. The requirements, however, dictate that the problem of design and construction of a qualifiable standard in the ultra-sensitive range had to be solved. There are a number of leak types which were considered - capillary leaks, orifice leaks, and the pore type leaks, among others. The capillary leak was not used because of the cracking or sorting effects that are common to this type leak. For example, a gas blend flowing through a capillary leak will result in the lighter gases passing through the leak first. The difficulty of fabricating the proper hole size in relation to the flow rate requirements ruled out the orifice type leak. The choice was the pore type leak which utilizes the basic concept of a stainless steel knife edge driven into a fixed section composed of stainless steel with a gold over-lay and maintained under force

  4. Prioritizing Test Cases for Memory Leaks in Android Applications

    Institute of Scientific and Technical Information of China (English)

    Ju Qian; Di Zhou

    2016-01-01

    Mobile applications usually can only access limited amount of memory. Improper use of the memory can cause memory leaks, which may lead to performance slowdowns or even cause applications to be unexpectedly killed. Although a large body of research has been devoted into the memory leak diagnosing techniques after leaks have been discovered, it is still challenging to find out the memory leak phenomena at first. Testing is the most widely used technique for failure discovery. However, traditional testing techniques are not directed for the discovery of memory leaks. They may spend lots of time on testing unlikely leaking executions and therefore can be inefficient. To address the problem, we propose a novel approach to prioritize test cases according to their likelihood to cause memory leaks in a given test suite. It firstly builds a prediction model to determine whether each test can potentially lead to memory leaks based on machine learning on selected code features. Then, for each input test case, we partly run it to get its code features and predict its likelihood to cause leaks. The most suspicious test cases will be suggested to run at first in order to reveal memory leak faults as soon as possible. Experimental evaluation on several Android applications shows that our approach is effective.

  5. LEAK: A source term generator for evaluating release rates from leaking vessels

    International Nuclear Information System (INIS)

    Clinton, J.H.

    1994-01-01

    An interactive computer code for estimating the rate of release of any one of several materials from a leaking tank or broken pipe leading from a tank is presented. It is generally assumed that the material in the tank is liquid. Materials included in the data base are acetonitrile, ammonia, carbon tetrachloride, chlorine, chlorine trifluoride, fluorine, hydrogen fluoride, nitric acid, nitrogen tetroxide, sodium hydroxide, sulfur hexafluoride, sulfuric acid, and uranium hexafluoride. Materials that exist only as liquid and/or vapor over expected ranges of temperature and pressure can easily be added to the data base file. The Fortran source code for LEAK and the data file are included with this report

  6. Proton imaging apparatus for proton therapy application

    International Nuclear Information System (INIS)

    Sipala, V.; Lo Presti, D.; Brianzi, M.; Civinini, C.; Bruzzi, M.; Scaringella, M.; Talamonti, C.; Bucciolini, M.; Cirrone, G.A.P.; Cuttone, G.; Randazzo, N.; Stancampiano, C.; Tesi, M.

    2011-01-01

    Radiotherapy with protons, due to the physical properties of these particles, offers several advantages for cancer therapy as compared to the traditional radiotherapy and photons. In the clinical use of proton beams, a p CT (Proton Computer Tomography) apparatus can contribute to improve the accuracy of the patient positioning and dose distribution calculation. In this paper a p CT apparatus built by the Prima (Proton Imaging) Italian Collaboration will be presented and the preliminary results will be discussed.

  7. Proton radioactivity from proton-rich nuclei

    International Nuclear Information System (INIS)

    Guzman, F.; Goncalves, M.; Tavares, O.A.P.; Duarte, S.B.; Garcia, F.; Rodriguez, O.

    1999-03-01

    Half-lives for proton emission from proton-rich nuclei have been calculated by using the effective liquid drop model of heavy-particle decay of nuclei. It is shown that this model is able to offer results or spontaneous proton-emission half-life-values in excellent agreement with the existing experimental data. Predictions of half-life-values for other possible proton-emission cases are present for null orbital angular momentum. (author)

  8. Concept for a Future Super Proton-Proton Collider

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jingyu; et al.

    2015-07-12

    Following the discovery of the Higgs boson at LHC, new large colliders are being studied by the international high-energy community to explore Higgs physics in detail and new physics beyond the Standard Model. In China, a two-stage circular collider project CEPC-SPPC is proposed, with the first stage CEPC (Circular Electron Positron Collier, a so-called Higgs factory) focused on Higgs physics, and the second stage SPPC (Super Proton-Proton Collider) focused on new physics beyond the Standard Model. This paper discusses this second stage.

  9. Concept for a Future Super Proton-Proton Collider

    CERN Document Server

    Tang, Jingyu; Chai, Weiping; Chen, Fusan; Chen, Nian; Chou, Weiren; Dong, Haiyi; Gao, Jie; Han, Tao; Leng, Yongbin; Li, Guangrui; Gupta, Ramesh; Li, Peng; Li, Zhihui; Liu, Baiqi; Liu, Yudong; Lou, Xinchou; Luo, Qing; Malamud, Ernie; Mao, Lijun; Palmer, Robert B.; Peng, Quanling; Peng, Yuemei; Ruan, Manqi; Sabbi, GianLuca; Su, Feng; Su, Shufang; Stratakis, Diktys; Sun, Baogeng; Wang, Meifen; Wang, Jie; Wang, Liantao; Wang, Xiangqi; Wang, Yifang; Wang, Yong; Xiao, Ming; Xing, Qingzhi; Xu, Qingjin; Xu, Hongliang; Xu, Wei; Witte, Holger; Yan, Yingbing; Yang, Yongliang; Yang, Jiancheng; Yuan, Youjin; Zhang, Bo; Zhang, Yuhong; Zheng, Shuxin; Zhu, Kun; Zhu, Zian; Zou, Ye

    2015-01-01

    Following the discovery of the Higgs boson at LHC, new large colliders are being studied by the international high-energy community to explore Higgs physics in detail and new physics beyond the Standard Model. In China, a two-stage circular collider project CEPC-SPPC is proposed, with the first stage CEPC (Circular Electron Positron Collier, a so-called Higgs factory) focused on Higgs physics, and the second stage SPPC (Super Proton-Proton Collider) focused on new physics beyond the Standard Model. This paper discusses this second stage.

  10. Acoustic detection for water/steam leak from a tube of LMFBR steam generator

    International Nuclear Information System (INIS)

    Sonoda, Masataka; Shindo, Yoshihisa

    1989-01-01

    Acoustic leak detector is useful for detecting more quickly intermediate leak than the existing hydrogen detector and is available for identification of leak location on the accident of water/steam leak from a tube of LMFBR steam generator. This paper presents the overview of HALD (High frequency Acoustics Leak Detection) system, which is more sensitive for leak detection and lower cost of equipment for identification of leak location than a low frequency type detector. (author)

  11. The EDDA experiment: proton-proton elastic scattering excitation functions at intermediate energies

    International Nuclear Information System (INIS)

    Hinterberher, F.

    1996-01-01

    The EDDA experiment is designed to provide a high precision measurement of proton-proton elastic scattering excitation functions ranging from 0.5 to 2.5 GeV of (lab) incident kinetic energy. It is an internal target experiment utilizing the proton beam of the cooler synchrotron COSY operated by KFA Juelich. The excitation functions are measured during the acceleration ramp of COSY. (author)

  12. Leak detection and location in MONJU steam generators

    International Nuclear Information System (INIS)

    Saito, T.; Kosugi, T.

    1978-01-01

    Leak detection system of MONJU steam generator depends mostly on in-sodium hydrogen detectors. The requirements on leak detector performance are determined from the point of view of protecting tube leak propagation due to wastage, and the process of determining the performance is shown briefly. Research and development activities on in-sodium hydrogen detectors are described and the specifications of leak detectors for MONJU are also presented. In-cover-gas hydrogen detector and acoustic detector are under development. Research and development activities on the leak location after steam generator shutdown by such methods as an electromagnetic method and ultrasonic method are described. The results of the research and development work on inserting the test probes into tubes are described also. An idea for finding the condition of tubes in the neighbourhood of the leak is also presented. (author)

  13. Leak detection and location in MONJU steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T; Kosugi, T [Prototype Reactor Office, Tokyo (Japan)

    1978-10-01

    Leak detection system of MONJU steam generator depends mostly on in-sodium hydrogen detectors. The requirements on leak detector performance are determined from the point of view of protecting tube leak propagation due to wastage, and the process of determining the performance is shown briefly. Research and development activities on in-sodium hydrogen detectors are described and the specifications of leak detectors for MONJU are also presented. In-cover-gas hydrogen detector and acoustic detector are under development. Research and development activities on the leak location after steam generator shutdown by such methods as an electromagnetic method and ultrasonic method are described. The results of the research and development work on inserting the test probes into tubes are described also. An idea for finding the condition of tubes in the neighbourhood of the leak is also presented. (author)

  14. Management of vacuum leak-detection processes, calibration, and standards

    International Nuclear Information System (INIS)

    Wilson, N.G.

    1985-01-01

    Vacuum leak detection requires integrated management action to ensure the successful production of apparatus having required leak tightness. Implementation of properly planned, scheduled, and engineered procedures and test arrangements are an absolute necessity to prevent unexpected, impractical, technically inadequate, or unnecessarily costly incidents in leak-testing operations. The use of standard procedures, leak standards appropriate to the task, and accurate calibration systems or devices is necessary to validate the integrity of any leak-test procedure. In this paper, the need for implementing these practices is discussed using case histories of typical examples of large complex vacuum systems. Aggressive management practices are of primary importance throughout a project's life cycle to ensure the lowest cost; this includes successful leak testing of components. It should be noted that the opinions and conclusions expressed in this paper are those of the author and are not those of the Los Alamos National Laboratory or the Department of Energy

  15. Research on pipeline leak detection method based on pressure and dynamic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Likun; Xiong, Min; Zhao, Jinyun; Wang, Hongchao; Xu, Bin; Yu, DongLiang; Sun, Yi; Cai, Yongjun [RnD center of PetroChina Pipeline Company, Langfang, Hebei, (China)

    2010-07-01

    Pipeline leakages are very frequent and need to be detected as fast as possible to avoid safety and environment issues. Many leakage detection processes have been developed. Acoustic wave methods based on static pressure and dynamic pressure are both used for pipeline leakage detection. This study investigated a new pipeline leak detection method based on joint pressure and dynamic pressure. A dynamic pressure transmitter was designed based on a piezoelectric dynamic pressure sensor. The study showed that the dynamic pressure signal should be used for pipeline leak detection with a quick-change in pipeline internal pressure, while the static pressure signal provides better results with a slow-change of pipeline internal pressure. The in-field results showed that the location error of dynamic pressure is reduced to 80 m with a leakage ratio of 0.6 % pipeline throughput.

  16. Lessons learned from MONJU sodium leak accident

    International Nuclear Information System (INIS)

    Nakai, Ryodai; Ito, Kazumoto; Nagata, Takashi

    2000-01-01

    MONJU sodium leak accident was a small accident with a large public impact. There was no injures or exposure to radiation, nor was there any loss of safety function such as reactor shutdown or reactor cooling. On the contrary a social impact is considerably large, whereby the plant remains shutdown. This paper describes the lessons learned from the accident, i.e. the impact of the accident and its cause, and the features on risk management in view of social aspect as well as technical aspect. (author)

  17. Leak before break experience in CANDU reactors

    International Nuclear Information System (INIS)

    Price, E.G.; Moan, G.D.; Coleman, C.E.

    1988-04-01

    The paper describes how the requirements for Leak-Before-Break are met in CANDU reactors. The requirements are based on operational and laboratory experience. After the onset of leakage in a fuel channel from a delayed hydride crack, time is available to the operator to take action before the crack grows to an unstable length. The time available is calculated using different models which use crack growth data from small specimen tests. When the results from crack growth behaviour experiments, carried out on components removed from reactor are used in the model, the time available for operator response is about 100 hours

  18. IR analyzer spots heavy water leaks

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    A correlation spectrometer developed by Barringer Research Ltd. (in collaboration with Atomic Energy of Canada and Ontario Hydro) is used to measure HDO concentrations in DTO in the final (distillation) stage of heavy-water production. A unit has been installed at Bruce Heavy Water Plant. Previously, such spectrometers had been installed to detect heavy-water leaks in CANDU reactors. The principle on which the instrument works is explained, with illustrations. It works by comparing the absorption at 2.9 μm, due to HDO, with that at 2.6 μm, due to both HDO and D 2 O. (N.D.H.)

  19. Cerebrospinal fluid leak mimicking allergic rhinitis.

    Science.gov (United States)

    Ricketti, Anthony J; Cleri, Dennis J; Porwancher, Richard B; Panesar, Mandip; Villota, Francisco J; Seelagy, Marc M

    2005-01-01

    Rhinitis and rhinorrhea are common clinical complaints that may be allergic or nonallergic in etiology. Distinguishing between allergic and nonallergic etiologies can be difficult but necessary for treatment. Here, we present a case of a 50-year-old woman with > 20 years of rhinorrhea before a diagnosis of cerebrospinal fluid leak and a life-threatening complication occurred. It is essential that no symptom, especially that which persists and resists treatment, is trivialized. Here, we establish how a careful history and evaluation will direct the clinician to the correct diagnosis.

  20. Leak detection device for reactor coolant

    International Nuclear Information System (INIS)

    Oshima, Koichiro.

    1990-01-01

    In a light water cooled reactor, if reactor coolants are leaked from pipelines in a pipeline chamber, activated products (N-16) are diffused together to an atmosphere in the pipeline chamber. N-16 is sucked from an extracting tube which is always sucking the atmosphere in the pipeline chamber to a sucking blower. Then, β-rays released from N-16 are monitored by a radiation monitor in a measuring chamber which is radiation-shielded from the pipeline chamber. Accordingly, since the radiation monitor can detect even slight leakage, the slight leakage of reactor coolants in the pipelines can be detected at an early stage. (I.N.)

  1. 340 Facility secondary containment and leak detection

    International Nuclear Information System (INIS)

    Bendixsen, R.B.

    1995-01-01

    This document presents a preliminary safety evaluation for the 340 Facility Secondary Containment and Leak Containment system, Project W-302. Project W-302 will construct Building 340-C which has been designed to replace the current 340 Building and vault tank system for collection of liquid wastes from the Pacific Northwest Laboratory buildings in the 300 Area. This new nuclear facility is Hazard Category 3. The vault tank and related monitoring and control equipment are Safety Class 2 with the remainder of the structure, systems and components as Safety Class 3 or 4

  2. Proton exchange membrane fuel cells

    CERN Document Server

    Qi, Zhigang

    2013-01-01

    Preface Proton Exchange Membrane Fuel CellsFuel CellsTypes of Fuel CellsAdvantages of Fuel CellsProton Exchange Membrane Fuel CellsMembraneCatalystCatalyst LayerGas Diffusion MediumMicroporous LayerMembrane Electrode AssemblyPlateSingle CellStackSystemCell Voltage Monitoring Module (CVM)Fuel Supply Module (FSM)Air Supply Module (ASM)Exhaust Management Module (EMM)Heat Management Module (HMM)Water Management Module (WMM)Internal Power Supply Module (IPM)Power Conditioning Module (PCM)Communications Module (COM)Controls Module (CM)SummaryThermodynamics and KineticsTheoretical EfficiencyVoltagePo

  3. Detection of steam generator tube leaks in pressurized water reactors

    International Nuclear Information System (INIS)

    Roach, W.H.

    1984-11-01

    This report addresses the early detection of small steam generator tube leaks in pressurized water reactors. It identifies physical parameters, establishes instrumentation performance goals, and specifies sensor types and locations. It presents a simple algorithm that yields the leak rate as a function of known or measurable quantities. Leak rates of less than one-tenth gram per second should be detectable with existing instrumentation

  4. Design of a Novel In-Pipe Reliable Leak Detector

    OpenAIRE

    Chatzigeorgiou, Dimitrios; Youcef-Toumi, Kamal; Ben-Mansour, Rached

    2013-01-01

    Leakage is the major factor for unaccounted losses in every pipe network around the world (oil, gas, or water). In most cases, the deleterious effects associated with the occurrence of leaks may present serious economical and health problems. Therefore, leaks must be quickly detected, located, and repaired. Unfortunately, most state-of-the-art leak detection systems have limited applicability, are neither reliable nor robust, while others depend on the user experience. In this paper, we prese...

  5. Telescope sipping the optimum fuel leak detection system

    International Nuclear Information System (INIS)

    Deleryd, R.

    1998-01-01

    The TELESCOPE Sipping technology is an evolutionary development from previous ABB fuel leak systems used in LWR reactors. The system utilizes the existing dynamics that cause numerous fission products to leak from a failed fuel rod when the fuel assembly is raised from a reactor core during core fuel alterations. The system can also be used by repair work in pool side inspection in order to detect leaking rods or to verify reconstituted assemblies as non leakers. (author)

  6. Detection of Leaks in Water Mains Using Ground Penetrating Radar

    OpenAIRE

    Alaa Al Hawari; Mohammad Khader; Tarek Zayed; Osama Moselhi

    2016-01-01

    Ground Penetrating Radar (GPR) is one of the most effective electromagnetic techniques for non-destructive non-invasive subsurface features investigation. Water leak from pipelines is the most common undesirable reason of potable water losses. Rapid detection of such losses is going to enhance the use of the Water Distribution Networks (WDN) and decrease threatens associated with water mains leaks. In this study, GPR approach was developed to detect leaks by implementing an appropriate imagin...

  7. Locating leaks in water mains using noise loggers

    OpenAIRE

    El-Abbasy, Mohammed S.; Mosleh, Fadi; Senouci, Ahmed; Zayed, Tarek; Al-Derham, Hassan

    2016-01-01

    Because of their potential danger to public health, economic loss, environmental damage, and energy waste, underground water pipelines leaks have received more attention globally. Researchers have proposed active leakage control approaches to localize, locate, and pinpoint leaks. Noise loggers have usually been used only for localizing leaks while other tools were used for locating and pinpointing. These approaches have resulted in additional cost and time. Thus, regression and artificial neu...

  8. WE-G-BRE-07: Proton Therapy Enhanced by Tumor-Targeting Gold Nanoparticles: A Pilot in Vivo Experiment at The Proton Therapy Center at MD Anderson Cancer Center

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, T; Grant, J; Wolfe, A; Gillin, M; Krishnan, S [MD Anderson Cancer Ctr., Houston, TX (United States)

    2014-06-15

    Purpose: Assess tumor-growth delay and survival in a mouse model of prostate cancer treated with tumor-targeting gold nanoparticles (AuNPs) and proton therapy. Methods: We first examined the accumulation of targeting nanoparticles within prostate tumors by imaging AuNPs with ultrasound-guided photoacoustics at 24h after the intravenous administration of goserelin-conjugated AuNPs (gAuNP) in three mice. Nanoparticles were also imaged at the cellular level with TEM in PC3 cells incubated with gAuNP for 24h. Pegylated AuNPs (pAuNP) were also imaged in vivo and in vitro for comparison. PC3 cells were then implanted subcutaneously in nude mice; 51mice with 8–10mm tumors were included. AuNPs were injected intravenously at 0.2%w/w final gold concentration 24h before irradiation. A special jig was designed to facilitate tumor irradiation perpendicular to the proton beam. Proton energy was set to 180MeV, the radiation field was 18×18cm{sup 2}, and 9cm or 13.5cm thick solid-water compensators were used to position the tumors at either the beam entrance (BE) or the SOBP. Physical doses of 5Gy were delivered to all tumors on a patient beam line at MD Anderson's Proton Therapy Center. Results: The photoacoustic experiment reveled that our nanoparticles leak from the tumor-feeding vasculature and accumulate within the tumor volume over time. Additionally, TEM images showed gAuNP are internalized in cancer cells, accumulating within the cytoplasm, whereas pAuNP are not. Tumor-growth was delayed by 11 or 32days in mice receiving gAuNP irradiated at the BE or the SOBP, relative to proton radiation alone. Survival curves (ongoing experiment) reveal that gAuNPs improved survival by 36% or 74% for tumors irradiated at the BE or SOBP. Conclusion: These important, albeit preliminary, in vivo findings reveal nanoparticles to be potent sensitizers to proton therapy. Further, conjugation of AuNPs to tumor-specific antigens that promote enhanced cellular internalization improved

  9. Experimental investigation of leak detection using mobile distributed monitoring system

    Science.gov (United States)

    Chen, Jiang; Zheng, Junli; Xiong, Feng; Ge, Qi; Yan, Qixiang; Cheng, Fei

    2018-01-01

    The leak detection of rockfill dams is currently hindered by spatial and temporal randomness and wide monitoring range. The spatial resolution of fiber Bragg grating (FBG) temperature sensing technology is related to the distance between measuring points. As a result, the number of measuring points should be increased to ensure that the precise location of the leak is detected. However, this leads to a higher monitoring cost. Consequently, it is difficult to promote and apply this technology to effectively monitor rockfill dam leakage. In this paper, a practical mobile distributed monitoring system with dual-tubes is used by combining the FBG sensing system and hydrothermal cycling system. This dual-tube structure is composed of an outer polyethylene of raised temperature resistance heating pipe, an inner polytetrafluoroethylene tube, and a FBG sensor string, among which, the FBG sensor string can be dragged freely in the internal tube to change the position of the measuring points and improve the spatial resolution. In order to test the effectiveness of the system, the large-scale model test of concentrated leakage in 13 working conditions is carried out by identifying the location, quantity, and leakage rate of leakage passage. Based on Newton’s law of cooling, the leakage state is identified using the seepage identification index ζ v that was confirmed according to the cooling curve. Results suggested that the monitoring system shows high sensitivity and can improve the spatial resolution with limited measuring points, and thus better locate the leakage area. In addition, the seepage identification index ζ v correlated well with the leakage rate qualitatively.

  10. Margins in high temperature leak-before-break assessments

    International Nuclear Information System (INIS)

    Budden, P.J.; Hooton, D.G.

    1997-01-01

    Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep

  11. Margins in high temperature leak-before-break assessments

    Energy Technology Data Exchange (ETDEWEB)

    Budden, P.J.; Hooton, D.G.

    1997-04-01

    Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep.

  12. Software-aided operation of modern industrial leak detectors

    Energy Technology Data Exchange (ETDEWEB)

    Grosse Bley, W. [INFICON GmbH, Koeln (Germany)

    2006-07-01

    When leak-testing parts with the tracer gas method, the ''no-indication'' response of the leak detector leaves the operator with the question whether there is really no leak present or the test instrument may be in a faulty (= insensitive) condition. Moreover, an operator being absent-minded or distracted may easily move the sniffer tip to the wrong spot on the test object or at least not to all required test areas. To make sure that the uncertainty about sensitivity is avoided specific artificial leaks (''test leaks'') are routinely used for frequent verification of the correct function and calibration of the leak detector. However, absent-minded, distracted or even lazy operators are not detected in this way. Recent software features implemented into INFICON leak detectors can help prevent mistakes of the above kind. Such features include intelligent filtering of the signal (preventing spurious noise), suppression of interfering gas effects, dynamic zeroing of the signal, simple on-site function tests with a built-in test leak, a complete spectrum of indications (optical, acoustical, tactile,..) if the trigger for leaky objects is exceeded and more. As an example of the latest achievements in this field the operator-controlling features of the new ECOTEC E3000 refrigerant leak detector from INFICON are described in some detail. It will become quite clear that product quality (in this case of refrigerators and air conditioners) is greatly enhanced by such supervising functions. (orig.)

  13. New helium sniffing device for locating very fine leaks

    International Nuclear Information System (INIS)

    Murakami, Y.; Shimomura, Y.; Abe, T.; Obara, K.

    1984-01-01

    A new helium sniffing method for leak checking large vacuum vessels is described. The low sensitivity problem of the conventional helium sniffing method has been overcome by increasing the gas draw rate from around leaks into the detector up to about 0.1 Pa m 3 /s. The devised system consists of a flexible stainless steel capillary tube 0.6 mm i.d. and 10 m long, a sorption pump using molecular sieve, and a helium leak detector in series. This method is particularly useful for locating very fine leaks down to 10 -11 Pa m 3 /s. Relevant theoretical considerations and experimental results are presented

  14. Proton movies

    CERN Multimedia

    2009-01-01

    A humorous short film made by three secondary school students received an award at a Geneva film festival. Even without millions of dollars or Hollywood stars at your disposal, it is still possible to make a good science fiction film about CERN. That is what three students from the Collège Madame de Staël in Carouge, near Geneva, demonstrated. For their amateur short film on the LHC, they were commended by the jury of the video and multimedia festival for schools organised by the "Media in education" service of the Canton of Geneva’s Public Education Department. The film is a spoof of a television news report on the LHC start-up. In sequences full of humour and imagination, the reporter conducts interviews with a very serious "Professor Sairne", some protons preparing for their voyage and even the neutrons that were rejected by the LHC. "We got the idea of making a film about CERN at the end of the summer," explains Lucinda Päsche, one of the three students. "We did o...

  15. Acoustic leak detection and ultrasonic crack detection

    International Nuclear Information System (INIS)

    Kupperman, D.S.; Claytor, T.N.; Groenwald, R.

    1983-10-01

    A program is under way to assess the effectiveness of current and proposed techniques for acoustic leak detection (ALD) in reactor coolant systems. An ALD facility has been constructed and tests have begun on five laboratory-grown cracks (three fatigue and two thermal-fatigue and two field-induced IGSCC specimens. After ultrasonic testing revealed cracks in the Georgia Power Co. HATCH-1 BWR recirculation header, the utility installed an ALD system. Data from HATCH-1 have given an indication of the background noise level at a BWR recirculation header sweepolet weld. The HATCH leak detection system was tested to determine the sensitivity and dynamic range. Other background data have been acquired at the Watts Bar Nuclear Reactor in Tennessee. An ANL waveguide system, including transducer and electronics, was installed and tested on an accumulator safety injection pipe. The possibility of using ultrasonic wave scattering patterns to discriminate between IGSCCs and geometric reflectors has been explored. Thirteen reflectors (field IGSCCs, graphite wool IGSCCs, weld roots, and slits) were examined. Work with cast stainless steel (SS) included sound velocity and attenuation in isotropic and anisotropic cast SS. Reducing anisotropy does not help reduce attenuation in large-grained material. Large artificial flaws (e.g., a 1-cm-deep notch with a 4-cm path) could not be detected in isotropic centrifugally cast SS (1 to 2-mm grains) by longitudinal or shear waves at frequencies of 1 MHz or greater, but could be detected with 0.5-MHz shear waves. 13 figures

  16. Numerical Study on POSRV Leak Detection

    International Nuclear Information System (INIS)

    Ko, Yong Sang; Baik, Se Jin; Cho, Yoon Jae; Yune, Seok Jeong; Kim, Eun Kee

    2015-01-01

    This study shows that the selected temperature measuring locations on the discharge lines of MV, MOPV, SLPV0 and SLPV1 are adequate for POSRV leakage detection. The analyzed temperature can be used as an alarm setpoint for leakage detection. Spring-Loaded Pilot Valve (SLPV) acts as a Reactor Coolant Pressure Boundary (RCPB) isolator in the closed position during the normal operation, but it opens automatically when the system pressure increases to its set pressure. The POSRVs shall be closed tightly to maintain the integrity of RCPB during the normal operation. Leakage through the RCPB is limited extremely. Each POSRV has several discharge lines for MV and auxiliary valves. Temperature instruments are installed on each discharge lines for leakage detection. In this study, Computational Fluid Dynamics (CFD) analyses using FLUENT are conducted to evaluate the temperature measurement for POSRV leakage detection. The followings are concluded from this study: 1) The determined temperature measuring points are adequate for effective leak detection, which are at the downstream of the first bend of each discharge line as close as to the discharge nozzle. 2) The alarm set point for detecting a leak is adequate and can be determined with considering the analysis results. 3) The temperature rise is sufficiently high to detect a small leakage. 4) The temperature sensing method is appropriate for finding a valve leakage

  17. Proton irradiation experiment for x-ray charge-coupled devices of the monitor of all-sky x-ray image mission onboard the international space station. 2. Degradation of dark current and identification of electron trap level

    CERN Document Server

    Miyata, E; Kamiyama, D

    2003-01-01

    We have investigated the radiation damage effects on a charge-coupled device (CCD) to be used for the Japanese X-ray mission, the monitor of all-sky X-ray image (MAXI), onboard the international space station (ISS). A temperature dependence of the dark current as a function of incremental dose is studied. We found that the protons having energy of >292 keV seriously increased the dark current of the devices. In order to improve the radiation tolerance of the devices, we have developed various device architectures to minimize the radiation damage in orbit. Among them, nitride oxide enables us to reduce the dark current significantly and therefore we adopted nitride oxide for the flight devices. We also compared the dark current of a device in operation and that out of operation during the proton irradiation. The dark current of the device in operation became twofold that out of operation, and we thus determined that devices would be turned off during the passage of the radiation belt. The temperature dependenc...

  18. Outcome of T4 (International Union Against Cancer Staging System, 7th edition) or Recurrent Nasal Cavity and Paranasal Sinus Carcinoma Treated With Proton Beam

    Energy Technology Data Exchange (ETDEWEB)

    Fukumitsu, Nobuyoshi, E-mail: fukumitsun@yahoo.co.jp [Proton Medical Research Center, University of Tsukuba, Tsukuba (Japan); Okumura, Toshiyuki; Mizumoto, Masashi; Oshiro, Yoshiko; Hashimoto, Takayuki; Kanemoto, Ayae; Hashii, Haruko; Ohkawa, Ayako; Moritake, Takashi; Tsuboi, Koji [Proton Medical Research Center, University of Tsukuba, Tsukuba (Japan); Tabuchi, Keiji; Wada, Tetsuro; Hara, Akira [Department of Otolaryngology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba (Japan); Sakurai, Hideyuki [Proton Medical Research Center, University of Tsukuba, Tsukuba (Japan)

    2012-06-01

    Purpose: To investigate the clinical features, prognostic factors, and toxicity of treatment for unresectable carcinomas of the nasal cavity and paranasal sinus (NCPS) treated with proton beam therapy (PBT). Methods and Materials: Seventeen patients (13 men, 4 women) with unresectable carcinomas of the NCPS who underwent PBT at University of Tsukuba between 2001 and 2007 were analyzed. The patients' median age was 62 years (range, 30-83 years). The tumors were located in the nasal cavity in 3 patients, the frontal sinus in 1, the ethmoid sinus in 9, and the maxillary sinus in 4. The clinical stage was Stage IVA in 5 cases, IVB in 10, and recurrent in 2. The tumors were deemed unresectable for medical reasons in 16 patients and because of refusal at a previous hospital 4 months earlier in 1 patient. All the patients received PBT irradiation dose of 22-82.5 GyE and a total of 72.4-89.6 GyE over 30-64 fractions (median 78 GyE over 36 fractions) with X-ray, with attention not exceeding the delivery of 50 GyE to the optic chiasm and brainstem. Results: The overall survival rate was 47.1% at 2 years and 15.7% at 5 years, and the local control rate was 35.0% at 2 years and 17.5% at 5 years. Invasion of the frontal or sphenoid sinus was a prognostic factor for overall survival or local control. Late toxicity of more than Grade 3 was found in 2 patients (brain necrosis in 1 and ipsilateral blindness in 1); however, no mortal adverse effects were observed. Conclusion: Proton beam therapy enabled a reduced irradiation dose to the optic chiasm and brainstem, enabling the safe treatment of unresectable carcinomas in the NCPS. Superior or posterior extension of the tumor influenced patient outcome.

  19. Outcome of T4 (International Union Against Cancer Staging System, 7th edition) or Recurrent Nasal Cavity and Paranasal Sinus Carcinoma Treated With Proton Beam

    International Nuclear Information System (INIS)

    Fukumitsu, Nobuyoshi; Okumura, Toshiyuki; Mizumoto, Masashi; Oshiro, Yoshiko; Hashimoto, Takayuki; Kanemoto, Ayae; Hashii, Haruko; Ohkawa, Ayako; Moritake, Takashi; Tsuboi, Koji; Tabuchi, Keiji; Wada, Tetsuro; Hara, Akira; Sakurai, Hideyuki

    2012-01-01

    Purpose: To investigate the clinical features, prognostic factors, and toxicity of treatment for unresectable carcinomas of the nasal cavity and paranasal sinus (NCPS) treated with proton beam therapy (PBT). Methods and Materials: Seventeen patients (13 men, 4 women) with unresectable carcinomas of the NCPS who underwent PBT at University of Tsukuba between 2001 and 2007 were analyzed. The patients' median age was 62 years (range, 30–83 years). The tumors were located in the nasal cavity in 3 patients, the frontal sinus in 1, the ethmoid sinus in 9, and the maxillary sinus in 4. The clinical stage was Stage IVA in 5 cases, IVB in 10, and recurrent in 2. The tumors were deemed unresectable for medical reasons in 16 patients and because of refusal at a previous hospital 4 months earlier in 1 patient. All the patients received PBT irradiation dose of 22–82.5 GyE and a total of 72.4–89.6 GyE over 30–64 fractions (median 78 GyE over 36 fractions) with X-ray, with attention not exceeding the delivery of 50 GyE to the optic chiasm and brainstem. Results: The overall survival rate was 47.1% at 2 years and 15.7% at 5 years, and the local control rate was 35.0% at 2 years and 17.5% at 5 years. Invasion of the frontal or sphenoid sinus was a prognostic factor for overall survival or local control. Late toxicity of more than Grade 3 was found in 2 patients (brain necrosis in 1 and ipsilateral blindness in 1); however, no mortal adverse effects were observed. Conclusion: Proton beam therapy enabled a reduced irradiation dose to the optic chiasm and brainstem, enabling the safe treatment of unresectable carcinomas in the NCPS. Superior or posterior extension of the tumor influenced patient outcome.

  20. Pipeline leak detection and location by on-line-correlation with a process computer

    International Nuclear Information System (INIS)

    Siebert, H.; Isermann, R.

    1977-01-01

    A method for leak detection using a correlation technique in pipelines is described. For leak detection and also for leak localisation and estimation of the leak flow recursive estimation algorithms are used. The efficiency of the methods is demonstrated with a process computer and a pipeline model operating on-line. It is shown that very small leaks can be detected. (orig.) [de

  1. Risk Factors for Gastrointestinal Leak after Bariatric Surgery: MBASQIP Analysis.

    Science.gov (United States)

    Alizadeh, Reza Fazl; Li, Shiri; Inaba, Colette; Penalosa, Patrick; Hinojosa, Marcelo W; Smith, Brian R; Stamos, Michael J; Nguyen, Ninh T

    2018-03-30

    Gastrointestinal leak remains one of the most dreaded complications in bariatric surgery. We aimed to evaluate risk factors and the impact of common perioperative interventions on the development of leak in patients who underwent laparoscopic bariatric surgery. Using the 2015 database of accredited centers, data were analyzed for patients who underwent laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass (LRYGB). Emergent, revisional, and converted cases were excluded. Multivariate logistic regression was used to analyze risk factors for leak, including provocative testing of anastomosis, surgical drain placement, and use of postoperative swallow study. Data from 133,478 patients who underwent laparoscopic sleeve gastrectomy (n = 92,495 [69.3%]) and LRYGB (n = 40,983 [30.7%]) were analyzed. Overall leak rate was 0.7% (938 of 133,478). Factors associated with increased risk for leak were oxygen dependency (adjusted odds ratio [AOR] 1.97), hypoalbuminemia (AOR 1.66), sleep apnea (AOR 1.52), hypertension (AOR 1.36), and diabetes (AOR 1.18). Compared with LRYGB, laparoscopic sleeve gastrectomy was associated with a lower risk of leak (AOR 0.52; 95% CI 0.44 to 0.61; p leak rate was higher in patients with vs without a provocative test (0.8% vs 0.4%, respectively; p leak rate was higher in patients with vs without a surgical drain placed (1.6% vs 0.4%, respectively; p leak rate was similar between patients with vs without swallow study (0.7% vs 0.7%; p = 0.50). The overall rate of gastrointestinal leak in bariatric surgery is low. Certain preoperative factors, procedural type (LRYGB), and interventions (intraoperative provocative test and surgical drain placement) were associated with a higher risk for leaks. Copyright © 2018 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  2. Proton-air and proton-proton cross sections

    Directory of Open Access Journals (Sweden)

    Ulrich Ralf

    2013-06-01

    Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

  3. Leak detection system for a high temperature fluid pipe

    International Nuclear Information System (INIS)

    Puyal, C.; Meuwisse, C.

    1989-01-01

    The leak detection system is made by a cable with at least two isolated electrical conductors, close to the wall of the pipe. The material of the cable is chosen so as to change its electrical characteristics if a leak causes heating of the cable. A detector at one end of the cable can measure the modifications of the electrical characteristics [fr

  4. Cook Strait cable leak investigation, March-June 1985

    International Nuclear Information System (INIS)

    Barry, B.J.; Fitzgerald, G.J.

    1985-09-01

    An investigation was made to locate a gas leak in an under-sea electric power cable. Krypton-85 was used as the tracer. Despite problems with the investigation there was strong evidence to suggest that the leak was in the joint between the land and sea portions of the cable. (auths)

  5. 241-AY-102 Leak Detection Pit Drain Line Inspection Report

    International Nuclear Information System (INIS)

    Boomer, Kayle D.; Engeman, Jason K.; Gunter, Jason R.; Joslyn, Cameron C.; Vazquez, Brandon J.; Venetz, Theodore J.; Garfield, John S.

    2014-01-01

    This document provides a description of the design components, operational approach, and results from the Tank AY-102 leak detection pit drain piping visual inspection. To perform this inspection a custom robotic crawler with a deployment device was designed, built, and operated by IHI Southwest Technologies, Inc. for WRPS to inspect the 6-inch leak detection pit drain line

  6. Leak detection in LMFBR steam generators during operation

    Energy Technology Data Exchange (ETDEWEB)

    Dumm, K [INTERATOM, Bergisch Gladbach (Germany)

    1978-10-01

    This paper deals with the following four main aspects: requirement on the leak detection of the SNR-300 steam generators; the hydrogen detector of SNR-300; remarks on the disadvantage of impurity detectors; and the first approach to acoustic leak detection systems.

  7. Commercial Grade Item (CGI) Dedication for Leak Detection Relays

    International Nuclear Information System (INIS)

    KOCH, M.R.; JOHNS, B.R.

    1999-01-01

    This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis

  8. Leak detection in LMFBR steam generators during operation

    International Nuclear Information System (INIS)

    Dumm, K.

    1978-01-01

    This paper deals with the following four main aspects: requirement on the leak detection of the SNR-300 steam generators; the hydrogen detector of SNR-300; remarks on the disadvantage of impurity detectors; and the first approach to acoustic leak detection systems

  9. Reliability evaluation of the Savannah River reactor leak detection system

    International Nuclear Information System (INIS)

    Daugherty, W.L.; Sindelar, R.L.; Wallace, I.T.

    1991-01-01

    The Savannah River Reactors have been in operation since the mid-1950's. The primary degradation mode for the primary coolant loop piping is intergranular stress corrosion cracking. The leak-before-break (LBB) capability of the primary system piping has been demonstrated as part of an overall structural integrity evaluation. One element of the LBB analyses is a reliability evaluation of the leak detection system. The most sensitive element of the leak detection system is the airborne tritium monitors. The presence of small amounts of tritium in the heavy water coolant provide the basis for a very sensitive system of leak detection. The reliability of the tritium monitors to properly identify a crack leaking at a rate of either 50 or 300 lb/day (0.004 or 0.023 gpm, respectively) has been characterized. These leak rates correspond to action points for which specific operator actions are required. High reliability has been demonstrated using standard fault tree techniques. The probability of not detecting a leak within an assumed mission time of 24 hours is estimated to be approximately 5 x 10 -5 per demand. This result is obtained for both leak rates considered. The methodology and assumptions used to obtain this result are described in this paper. 3 refs., 1 fig., 1 tab

  10. Prediction of Gas Leak Tightness of Superplastically Formed Products

    NARCIS (Netherlands)

    Snippe, Q.H.C.; Meinders, Vincent T.; Barlat, F; Moon, Y.H.; Lee, M.G.

    2010-01-01

    In some applications, in this case an aluminium box in a subatomic particle detector containing highly sensitive detecting devices, it is important that a formed sheet should show no gas leak from one side to the other. In order to prevent a trial-and-error procedure to make this leak tight box, a

  11. Coil embolization of an anastomotic leak after ascending aorta replacement

    DEFF Research Database (Denmark)

    Nørgaard, Anders; Andersen, Lars Ib; Haahr, P.E.

    2008-01-01

    treated aneurysm in the ascending thoracic aorta complicated with an anastomotic leak. If a short prosthesis (6 cm) had been available, the anastomotic leak would have been treated with endovascular repair. In lack of this prosthesis, we were forced to treat the patient with a method not generally...

  12. Air leak after lung resection: pathophysiology and patients' implications.

    Science.gov (United States)

    Pompili, Cecilia; Miserocchi, Giuseppe

    2016-02-01

    Protocols for the management of air leaks are critical aspects in the postoperative course of patients following lung resections. Many investigations in the last decade are focusing on the chest tube modalities or preventative measures, however, little is known about the pathophysiology of air leak and the patient perception of this common complication. This review concentrates on understanding the reasons why a pulmonary parenchyma may start to leak or an air leak may be longer than others. Experimental works support the notion that lung overdistension may favor air leak. These studies may represent the basis of future investigations. Furthermore, the standardization of nomenclature in the field of pleural space management and the creation of novel air leak scoring systems have contributed to improve the knowledge among thoracic surgeons and facilitate the organization of trials on this matter. We tried to summarize available evidences about the patient perception of a prolonged air leak and about what would be useful for them in order to prevent worsening of their quality of life. Future investigations are warranted to better understand the pathophysiologic mechanisms responsible of prolonged air leak in order to define tailored treatments and protocols. Improving the care at home with web-based telemonitoring or real time connected chest drainage may in a future improve the quality of life of the patients experience this complication and also enhance hospital finances.

  13. Measurement error in pressure-decay leak testing

    International Nuclear Information System (INIS)

    Robinson, J.N.

    1979-04-01

    The effect of measurement error in presssure-decay leak testing is considered, and examples are presented to demonstrate how it can be properly accomodated in analyzing data from such tests. Suggestions for more effective specification and conduct of leak tests are presented

  14. Cooling device for leaking fluid from a centrifugal pump

    International Nuclear Information System (INIS)

    Raymond, J.R.; Thomson, C.I.

    1978-01-01

    The patented device consists of an integrated heat exchanger in a centrifugal primary cooling circuit pump whose purpose is to cool the coolant medium which leaks along the pump shaft so that the shaft seals are not damaged. The cooling water passes through spirally arranged banks of tubes round the shaft, with baffle plates to direct the leaking coolant. (JIW)

  15. Leaking tankers: how much oil was spilled?

    International Nuclear Information System (INIS)

    Simecek-Beatty, D. A.; Lehr, W. J.; Lankford, J. F.

    1997-01-01

    A model to estimate leak rates from tankers has been developed for use in emergency situations when more direct oil-loss estimation methods are not available. The model includes algorithms for gravity outflow and air and water ingestion. Three laboratory tests were conducted using fresh water and canola oil to evaluate the model output. Comparison with results from the laboratory experiments indicate good correlation of model results with measured data. However, it is not yet possible in the case of very large crude carriers to answer the question 'how much oil was spilled?' Sensitivity analysis and further laboratory testing were suggested to determine the effect of factors such as: pressure vacuum relief valves that prevent cavitation in the event of tank puncture; changing outside water levels due to wave and tidal action; tank and hole dimensions; and the amount and density of the product.10 refs., 4 figs

  16. Applicability of the leak before break concept

    International Nuclear Information System (INIS)

    1993-06-01

    Within the framework of the IAEA Extrabudgetary Programme on the Safety of WWER-440 Model 230 NPPs, a list of safety issues requiring broad studies of general interest have been agreed upon by an Advisory Group which met in Vienna in September 1990. The information on the status of the issues, and on amount of work already completed and under way in various countries, needs to be compiled. Moreover, an evaluation of what further work is required to resolve each of the issues is also necessary. In view of this, the IAEA has started the preparation of a series of status reports on the various issues. This report on the generic safety issue ''Applicability of the Leak Before Break Concept'' presents a comprehensive survey of technical information available in the field and identifies those which require further investigation. 50 refs, 15 figs, 2 tabs

  17. The FAIR proton linac

    International Nuclear Information System (INIS)

    Kester, O.

    2015-01-01

    FAIR - the Facility for Antiproton and Ion Research in Europe - constructed at GSI in Darmstadt comprises an international centre of heavy ion accelerators that will drive heavy ion and antimatter research. FAIR will provide worldwide unique accelerator and experimental facilities, allowing a large variety of fore-front research in physics and applied science. FAIR will deliver antiproton and ion beams of unprecedented intensities and qualities. The main part of the FAIR facility is a sophisticated accelerator system, which delivers beams to different experiments of the FAIR experimental collaborations - APPA, NuSTAR, CBM and PANDA - in parallel. Modern H-type cavities offer highest shunt impedances of resonant structures of heavy ion linacs at low beam energies < 20 MeV/u and enable the acceleration of intense proton and ion beams. One example is the interdigital H-type structure. The crossed-bar H-cavities extend these properties to high energies even beyond 100 MeV/u. Compared to conventional Alvarez cavities, these crossed-bar (CH) cavities feature much higher shunt impedance at low energies. The design of the proton linac is based on those cavities

  18. Superoxide activates a GDP-sensitive proton conductance in skeletal muscle mitochondria from king penguin (Aptenodytes patagonicus).

    Science.gov (United States)

    Talbot, Darren A; Hanuise, Nicolas; Rey, Benjamin; Rouanet, Jean-Louis; Duchamp, Claude; Brand, Martin D

    2003-12-26

    We present the partial nucleotide sequence of the avian uncoupling protein (avUCP) gene from king penguin (Aptenodytes patagonicus), showing that the protein is 88-92% identical to chicken (Gallus gallus), turkey (Meleagris gallopavo), and hummingbird (Eupetomena macroura). We show that superoxide activates the proton conductance of mitochondria isolated from king penguin skeletal muscle. GDP abolishes the superoxide-activated proton conductance, indicating that it is mediated via avUCP. In the absence of superoxide there is no GDP-sensitive component of the proton conductance from penguin muscle mitochondria demonstrating that avUCP plays no role in the basal proton leak.

  19. Fully automatic AI-based leak detection system

    Energy Technology Data Exchange (ETDEWEB)

    Tylman, Wojciech; Kolczynski, Jakub [Dept. of Microelectronics and Computer Science, Technical University of Lodz in Poland, ul. Wolczanska 221/223, Lodz (Poland); Anders, George J. [Kinectrics Inc., 800 Kipling Ave., Toronto, Ontario M8Z 6C4 (Canada)

    2010-09-15

    This paper presents a fully automatic system intended to detect leaks of dielectric fluid in underground high-pressure, fluid-filled (HPFF) cables. The system combines a number of artificial intelligence (AI) and data processing techniques to achieve high detection capabilities for various rates of leaks, including leaks as small as 15 l per hour. The system achieves this level of precision mainly thanks to a novel auto-tuning procedure, enabling learning of the Bayesian network - the decision-making component of the system - using simulated leaks of various rates. Significant new developments extending the capabilities of the original leak detection system described in and form the basis of this paper. Tests conducted on the real-life HPFF cable system in New York City are also discussed. (author)

  20. Steam leak detection method in pipeline using histogram analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Se Oh; Jeon, Hyeong Seop; Son, Ki Sung; Chae, Gyung Sun [Saean Engineering Corp, Seoul (Korea, Republic of); Park, Jong Won [Dept. of Information Communications Engineering, Chungnam NationalUnversity, Daejeon (Korea, Republic of)

    2015-10-15

    Leak detection in a pipeline usually involves acoustic emission sensors such as contact type sensors. These contact type sensors pose difficulties for installation and cannot operate in areas having high temperature and radiation. Therefore, recently, many researchers have studied the leak detection phenomenon by using a camera. Leak detection by using a camera has the advantages of long distance monitoring and wide area surveillance. However, the conventional leak detection method by using difference images often mistakes the vibration of a structure for a leak. In this paper, we propose a method for steam leakage detection by using the moving average of difference images and histogram analysis. The proposed method can separate the leakage and the vibration of a structure. The working performance of the proposed method is verified by comparing with experimental results.

  1. The benefits of SCADA integrated pipeline leak detection

    Energy Technology Data Exchange (ETDEWEB)

    Pichler, Ruprecht M.J. [Pichler Engineering GmbH, Munich (Germany)

    2003-07-01

    Software based leak detection and locating for pipelines based upon evaluation of hydraulic parameters is a widely used approach to online pipeline integrity monitoring. Typically, these software packages are installed in a stand-alone configuration with a narrow bandwidth interface to the pipeline SCADA system. However, the performance characteristics of the SCADA system and interface do have a substantial impact on the performance of the leak detection system. By a tight integration of leak detection software into the SCADA system, a source of false alarms typically experienced with leak detection systems can be eliminated, the overall performance of the leak detection system can be improved, and the project costs can be reduced. (author)

  2. Reliability of leak detection systems in light water reactors

    International Nuclear Information System (INIS)

    Kupperman, D.S.

    1987-01-01

    US Nuclear Regulatory Commission Guide 1.45 recommends the use of at least three different detection methods in reactors to detect leakage. Monitoring of both sump-flow and airborne particulate radioactivity is recommended. A third method can involve either monitoring of condensate flow rate from air coolers or monitoring of airborne gaseous radioactivity. Although the methods currently used for leak detection reflect the state of the art, other techniques may be developed and used. Since the recommendations of Regulatory Guide 1.45 are not mandatory, the technical specifications for 74 operating plants have been reviewed to determine the types of leak detection methods employed. In addition, Licensee Event Report (LER) Compilations from June 1985 to June 1986 have been reviewed to help establish actual capabilities for detecting leaks and determining their source. Work at Argonne National Laboratory has demonstrated that improvements in leak detection, location, and sizing are possible with advanced acoustic leak detection technology

  3. Evaluation of methodologies for the calculation of leak rates for pressure retaining components with crack-like leaks

    International Nuclear Information System (INIS)

    Sievers, Juergen; Heckmann, Klaus; Blaesius, Christoph

    2015-06-01

    For the demonstration of break preclusion for pressure retaining components in nuclear power plants, the nuclear safety standard KTA 3206 determines also the requirements for the leak-before-break verification. For this procedure, it has to be ensured that a wall-penetrating crack is subcritical with respect to instable growth, and that the resulting leakage under stationary operation conditions can be detected by a leak detection system. Within the scope of the project 3613R01332 analyses with respect to conservative estimates of the leak rates in case of detections regarding break preclusion were performed by means of leak rate models being available at GRS. For this purpose, conservative assumptions in the procedure were quantified by comparative calculations concerning selected leak rate experiments and the requirements regarding the determination of leak rates indicated in the KTA 3206 were verified and specified. Moreover, the models were extended and relevant recommendations for the calculation procedure were developed. During the investigations of leak rate tests the calculation methods were validated, qualified by means of both examples indicated in KTA 3206 and applied to a postulated leak accident in the cooling circuit of a PWR. For the calculation of leak rates several simplified solution methods which are included in the GRS program WinLeck were applied, and for the simulation of a leak accident the large-scale programs ANSYS Mechanical and ATHLET (thermohydraulics program developed by GRS) were used. When applying simplified methods for the calculation of leak rates using the limiting curve for the friction factor which has been derived during the project and which is included in the KTA 3206 attention has to be paid to the fact that in case of small flow lengths the entrance loss can dominate compared to the friction loss. However, the available data do not suffice in order to make a quantitative statement with respect to limits of applicability

  4. Transcatheter closure of paravalvular leaks using a paravalvular leak device – a prospective Polish registry

    Directory of Open Access Journals (Sweden)

    Grzegorz Smolka

    2016-05-01

    Full Text Available Introduction : Transcatheter paravalvular leak closure (TPVLC has become an established treatment option but is mostly performed with off-label use of different non-dedicated occluders. The first one specifically designed for TPVLC is the paravalvular leak device (PLD – Occlutech. Aim : We present initial short-term results of a prospective registry intended to assess the safety and efficacy of TPVLC with PLD. Material and methods : We screened patients with paravalvular leak (PVL after surgical valve replacement (SVR. Heart failure symptoms and/or hemolytic anemia were indications for TPVLC. Patients were selected according to PVL anatomy by RT 3D TEE. Only those considered appropriate for closure with a single PLD were enrolled. The procedures were performed via transvascular or transapical access using type W (waist PLDs only. Results : Thirty patients with 34 PVLs (18 aortic, 16 mitral were included. We implanted 35 PLDs with a total device success rate of 94.3% (100% for aortic, 88.2% for mitral. The procedural success rate, encompassing device success without in-hospital complications, was 94.1% (100% for aortic, 93.8% for mitral. During the follow-up period we recorded an increase of hemoglobin concentration (3.9 to 4.1 g/dl, red blood count (11.6 to 12.2 M/mm3 and functional improvement by NYHA class. Conclusions : Paravalvular leak device type W is a promising TPVLC device, but meticulous preselection of patients based on imaging of PVL anatomy is a prerequisite. A PLD should only be chosen for channels shorter than 5 mm. Size of the device should match the PVL cross-sectional area without any oversizing. Such an approach facilitates high device and procedural success rates.

  5. Steam leak detection in advance reactors via acoustics method

    International Nuclear Information System (INIS)

    Singh, Raj Kumar; Rao, A. Rama

    2011-01-01

    Highlights: → Steam leak detection system is developed to detect any leak inside the reactor vault. → The technique uses leak noise frequency spectrum for leak detection. → Testing of system and method to locate the leak is also developed and discussed in present paper. - Abstract: Prediction of LOCA (loss of coolant activity) plays very important role in safety of nuclear reactor. Coolant is responsible for heat transfer from fuel bundles. Loss of coolant is an accidental situation which requires immediate shut down of reactor. Fall in system pressure during LOCA is the trip parameter used for initiating automatic reactor shut down. However, in primary heat transport system operating in two phase regimes, detection of small break LOCA is not simple. Due to very slow leak rates, time for the fall of pressure is significantly slow. From reactor safety point of view, it is extremely important to find reliable and effective alternative for detecting slow pressure drop in case of small break LOCA. One such technique is the acoustic signal caused by LOCA in small breaks. In boiling water reactors whose primary heat transport is to be driven by natural circulation, small break LOCA detection is important. For prompt action on post small break LOCA, steam leak detection system is developed to detect any leak inside the reactor vault. The detection technique is reliable and plays a very important role in ensuring safety of the reactor. Methodology developed for steam leak detection is discussed in present paper. The methods to locate the leak is also developed and discussed in present paper which is based on analysis of the signal.

  6. Proton therapy device

    International Nuclear Information System (INIS)

    Tronc, D.

    1994-01-01

    The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs

  7. Essential results of analyses accompanying the leak rate experiments E22 at HDR

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1994-01-01

    Under the E22 test group of phase III of the HDR safety programme, experiments were performed on the crack opening and leak rate behaviour of pipe components of smaller nominal bores. The experiments were complemented by computations, in particular verifications, to qualify the computation models as one of the main aims of the HDR safety programme. Most of the analyses to determine crack openings were performed by means of the finite-element method, including elastic-plastic materials behaviour and, complementarily, assessing engineering methods. The leak rate was calculated by means of separate 2-phase computation models. Altogether, it may be concluded from the structural and fracture mechanical experiments with pipes, elbows and branch pieces, that crack openings and incipient cracks at loading with internal pressure or bending moment can be described with good accuracy by means of the finite-element programme ADINA and the developed FE-models. (orig.) [de

  8. Study on Leak Detection of the Pipeline System by Acoustic Emission

    International Nuclear Information System (INIS)

    Yoon, D. J.; Kim, C. J.

    1987-01-01

    Leak detection testing for the pipeline system was performed by the acoustic emission method. It was found that the detected signal spectrum was influenced by the frequency response of sensors and pressure changes. AE parameters and frequency spectrum distributions were used to analyze the leak signals. The slope rise time of AE parameters were the important factors for distinguishing leak signals. The amplitude of leak signal was more affected by the changes of leak, rate and pressure than those of leak type

  9. International

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  10. Leak testing of cryogenic components — problems and solutions

    Science.gov (United States)

    Srivastava, S. P.; Pandarkar, S. P.; Unni, T. G.; Sinha, A. K.; Mahajan, K.; Suthar, R. L.

    2008-05-01

    A prototype of Cold Neutron Source (CNS) for Dhruva Reactor is being manufactured at Centre for Design and Manufacture (CDM), BARC, Mumbai for validating the mechanical and thermal engineering design aspects, besides checking the integrity of all joints and components at low temperature, 77K. Task of a Cold Neutron Source is to generate cold neutrons by cooling down the thermal neutrons, which are originally produced in a nuclear research reactor. The complete Cold Neutron Source system comprises a complex arrangement of moderator pot, transfer line (piping), pumps, refrigerators, storage tanks, a heat exchanger and associated controls and instrumentation. The heart of the system is moderator pot in which water (moderator) is cooled down by Liquid Nitrogen (LN2) being circulated through an annular cavity machined on the walls of the pot. Transfer lines for LN2 basically consist of two concentric Stainless Steel flexible pipes, which are joined to the inlet and outlet Aluminium tubes of the moderator pot through transition joints. Leak in any component may result in loss of liquid Nitrogen, degradation of vacuum, which in turn may affect the heat removal efficiency of the source. Hence, leak testing was considered a very important quality control tool and all joints and components were subjected to helium leak test using mass spectrometer leak detector (MSLD) at cryogenic temperature. During one of the earlier experiments, flow of LN2 through inner flexible pipe of the transfer line resulted in rise of pressure in the vacuum annulus and sweating on the outer flexible pipe. After investigations it was found that large thermal stress compounded with mechanical stress resulted in cracks in the inner pipe. Accordingly design was modified to get leak proof transfer line assembly. Further, during leak testing of thin wall moderator pot, gross leak was observed on the outer jacket welded joint. Leak was so large that even a small amount of Helium gas in the vicinity of the

  11. Strange magnetism and the anapole structure of the proton

    International Nuclear Information System (INIS)

    Hasty, R.; Beck, D.H.; Danagoulian, A.; Blake, A.; Carr, R.; Covrig, S.; Filipoone, B.W.; Ito, T.M.; Gao, J.; Jones, C.E.; Lee, P.; McKeown, R.D.; Savu, V.; Beise, E.J.; Breuer, H.; Spayde, D.T.; Tieulent, R.; Herda, M.C.; Barkhuff, D.; Dodson, G.; Dow, K.; Farkhondeh, M.; Kowalski, S.; Tsentalovich, E.; Yang, B.; Zwart, T.; Hawthorne-Allen, A.M.; Pitt, M.; Ritter, J.; Korsch, W.; Mueller, B.; Wells, S.P.; Averett, T.; Roche, J.; Kramer, K.

    2000-01-01

    The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

  12. Proton spin structure in the rest frame

    International Nuclear Information System (INIS)

    Zavada, P.

    1997-01-01

    It is shown that the quark-parton model in the standard infinite momentum approach overestimates the proton spin structure function g 1 (x) in comparison with the approach taking consistently into account the internal motion of quarks described by a spherical phase space in the proton rest frame. Particularly, it is shown the first moment of the spin structure function in the latter approach, assuming only the valence quarks contribution to the proton spin, does not contradict the experimental data. copyright 1997 The American Physical Society

  13. The mechanism of electron gating in proton pumping cytochrome c oxidase: the effect of pH and temperature on internal electron transfer.

    Science.gov (United States)

    Brzezinski, P; Malmström, B G

    1987-10-29

    Electron-transfer reactions following flash photolysis of the mixed-valence cytochrome oxidase-CO complex have been measured at 445, 598 and 830 nm between pH 5.2 and 9.0 in the temperature range of 0-25 degrees C. There is a rapid electron transfer from the cytochrome a3-CuB pair to CuA (time constant: 14200 s-1), which is followed by a slower electron transfer to cytochrome a. Both the rate and the amplitude of the rapid phase are independent of pH, and the rate in the direction from CuA to cytochrome a3-CuB is practically independent of temperature. The second phase depends strongly on pH due to the titration of an acid-base group with pKa = 7.6. The equilibrium at pH 7.4 corresponds to reduction potentials of 225 and 345 mV for cytochrome a and a3, respectively, from which it is concluded that the enzyme is in a different conformation compared to the fully oxidized form. The results have been used to suggest a series of reaction steps in a cycle of the oxidase as a proton pump. Application of the electron-transfer theory to the temperature-dependence data suggests a mechanism for electron gating in the pump. Reduction of both cytochrome a and CuA leads to a conformational change, which changes the structure of cytochrome a3-CuB in such a way that the reorganizational barrier for electron transfer is removed and the driving force is increased.

  14. Elastic proton-proton scattering at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Yip, K.

    2011-09-03

    Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

  15. Baryon production in proton-proton collisions

    International Nuclear Information System (INIS)

    Liu, F.M.; Werner, K.

    2002-01-01

    Motivated by the recent rapidity spectra of baryons and antibaryons in pp collisions at 158 GeV and the Ω-bar/Ω ratio discussion, we reviewed string formation mechanism and some string models. This investigation told us how color strings are formed in ultrarelativistic proton-proton collisions

  16. Air-Leak Effects on Ear-Canal Acoustic Absorbance

    Science.gov (United States)

    Rasetshwane, Daniel M.; Kopun, Judy G.; Gorga, Michael P.; Neely, Stephen T.

    2015-01-01

    Objective: Accurate ear-canal acoustic measurements, such as wideband acoustic admittance, absorbance, and otoacoustic emissions, require that the measurement probe be tightly sealed in the ear canal. Air leaks can compromise the validity of the measurements, interfere with calibrations, and increase variability. There are no established procedures for determining the presence of air leaks or criteria for what size leak would affect the accuracy of ear-canal acoustic measurements. The purpose of this study was to determine ways to quantify the effects of air leaks and to develop objective criteria to detect their presence. Design: Air leaks were simulated by modifying the foam tips that are used with the measurement probe through insertion of thin plastic tubing. To analyze the effect of air leaks, acoustic measurements were taken with both modified and unmodified foam tips in brass-tube cavities and human ear canals. Measurements were initially made in cavities to determine the range of critical leaks. Subsequently, data were collected in ears of 21 adults with normal hearing and normal middle-ear function. Four acoustic metrics were used for predicting the presence of air leaks and for quantifying these leaks: (1) low-frequency admittance phase (averaged over 0.1–0.2 kHz), (2) low-frequency absorbance, (3) the ratio of compliance volume to physical volume (CV/PV), and (4) the air-leak resonance frequency. The outcome variable in this analysis was the absorbance change (Δabsorbance), which was calculated in eight frequency bands. Results: The trends were similar for both the brass cavities and the ear canals. ΔAbsorbance generally increased with air-leak size and was largest for the lower frequency bands (0.1–0.2 and 0.2–0.5 kHz). Air-leak effects were observed in frequencies up to 10 kHz, but their effects above 1 kHz were unpredictable. These high-frequency air leaks were larger in brass cavities than in ear canals. Each of the four predictor variables

  17. Incidence and risk factors predisposing anastomotic leak after transhiatal esophagectomy

    International Nuclear Information System (INIS)

    Tabatabai, Abbas; Hashemi, Mozaffar; Mohajeri, Gholamreza; Ahmadinejad, Mojtaba; Khan, Ishfaq Abass; Haghdani, Saeid

    2009-01-01

    The objective of our study was to identify the incidence and risk factors of anastomotic leaks following transhiatal esophagectomy (THE). A prospective study was conducted on 61 patients treated for carcinoma of the esophagus between 2006 and 2007. We examined the following variables: age, gender, preoperative cardiovascular function, intraoperative complications such as hypotension, arrhythmia, mediastinal manipulation period, blood loss volume, blood transfusion, duration of surgery, postoperative complications such as anastomotic leak, anastomotic stricture, requiring reoperation, respiratory complications, and total morbidity and mortality. Variables were compared between the patients with and without anastomotic leak. T-test for quantitative variables and Chi-square test for qualitative variables were used to find out any relationship. P value less than 0.05 was considered significant. Out of 61 patients, anastomotic leaks occurred in 13 (21.3%). Weight loss, forced expiratory volume (FEV1) < 2 lit, preoperative albumin, intaoperative blood loss volume, and respiratory complication were associated with the anastomotic leak in patients undergoing THE. Anastomotic leaks were the leading cause of postoperative morbidity, anastomotic stricture, and reoperation. Anastomotic leakage is a life-threatening postoperative complication. Careful attention to the factors contributing to the development of a leak can reduce the incidence of anastomotic complications postoperatively. (author)

  18. Hollow-core fiber sensing technique for pipeline leak detection

    Science.gov (United States)

    Challener, W. A.; Kasten, Matthias A.; Karp, Jason; Choudhury, Niloy

    2018-02-01

    Recently there has been increased interest on the part of federal and state regulators to detect and quantify emissions of methane, an important greenhouse gas, from various parts of the oil and gas infrastructure including well pads and pipelines. Pressure and/or flow anomalies are typically used to detect leaks along natural gas pipelines, but are generally very insensitive and subject to false alarms. We have developed a system to detect and localize methane leaks along gas pipelines that is an order of magnitude more sensitive by combining tunable diode laser spectroscopy (TDLAS) with conventional sensor tube technology. This technique can potentially localize leaks along pipelines up to 100 km lengths with an accuracy of +/-50 m or less. A sensor tube buried along the pipeline with a gas-permeable membrane collects leaking gas during a soak period. The leak plume within the tube is then carried to the nearest sensor node along the tube in a purge cycle. The time-to-detection is used to determine leak location. Multiple sensor nodes are situated along the pipeline to minimize the time to detection, and each node is composed of a short segment of hollow core fiber (HCF) into which leaking gas is transported quickly through a small pressure differential. The HCF sensing node is spliced to standard telecom solid core fiber which transports the laser light for spectroscopy to a remote interrogator. The interrogator is multiplexed across the sensor nodes to minimize equipment cost and complexity.

  19. Detection of steam generator tube leaks in pressurized water reactors

    International Nuclear Information System (INIS)

    Roach, W.H.

    1985-01-01

    This report addresses the early detection of small steam generator tube leaks in pressurized water reactors. It discusses the third, and final, year's work on an NRC-funded project examining diagnostic instrumentation in water reactors. The first two years were broad in coverage, concentrating on anticipatory measurements for detection of potential problems in both pressurized- and boiling-water reactors, with recommendations for areas of further study. One of these areas, the early detection of small steam tube leaks in PWRs, formed the basis of study for the last year of the project. Four tasks are addressed in this study of the detection of steam tube leaks. (1) Determination of which physical parameters indicate the onset of steam generator tube leaks. (2) Establishing performance goals for diagnostic instruments which could be used for early detection of steam generator tube leaks. (3) Defining the diagnostic instrumentation and their location which satisfy Items 1 and 2 above. (4) Assessing the need for diagnostic data processing and display. Parameters are identified, performance goals established, and sensor types and locations are specified in the report, with emphasis on the use of existing instrumentation with a minimum of retrofitting. A simple algorithm is developed which yields the leak rate as a function of known or measurable quantities. The conclusion is that leak rates of less than one-tenth gram per second should be detectable with existing instrumentation. (orig./HP)

  20. Study on the leak rate test for HANARO reactor building

    International Nuclear Information System (INIS)

    Choi, Y. S.; Kim, Y. K.; Kim, M. J.; Park, J. M.; Woo, J. S.

    2002-01-01

    The reactor building of HANARO adopts the confinement concept, which allows a certain amount of air leakage. In order to restrict the air leakage through the confinement boundary, negative pressure of at least 2.5 mmWG is maintained in normal operating condition while maintaining 25 mmWG of negative pressure in abnormal condition, the inside air filtered by a train of charcoal filter is released to the atmosphere through the stack. In this situation, if the emergency ventilation system is not operable, the reactor building is isolated from the outside then the trapped air inside will be leaked out through the building by ground release concept. As the leak rate may be affected by an effect of wind velocity outside the reactor building, the air tightness of confinement should be maintained to limit the leak rate below the allowable value. The local leak rate test method was used since the beginning of the commissioning until July 1999. However it has been pointed out as a defect that the method is so susceptible to the change of temperature and atmospheric pressure during testing. For more accurate leak rate testing, we have introduced a new test method. We have periodically carried out the new leak rate testing and the results indicate that the bad effect by the temperature and atmospheric pressure change is considerably reduced, which gives more stable leak rate measurement

  1. Method of judging leak sources in a reactor container

    International Nuclear Information System (INIS)

    Maeda, Katsuji.

    1984-01-01

    Purpose: To enable exact judgement for leak sources upon leak accident in a reactor container of BWR type power plants as to whether the sources are present in the steam system or coolant system. Method: If leak is resulted from the main steam system, the hydrogen density in the reactor container is about 170 times as high as the same amount of leak from the reactor water. Accordingly, it can be judged whether the leak source is present in the steam system or reactor water system based on the change in the indication of hydrogen densitometer within the reactor container, and the indication from the drain amount from the sump in the container or the indication of a drain flow meter in the container dehumidifier. Further, I-131, Na-24 and the like as the radioactive nucleides in sump water of the container are measured to determine the density ratio R = (I-131)/(Na-24), and it is judged that the leak is resulted in nuclear water if the density ratio R is equal to that of reactor water and that the leak is resulted from the main steam or like other steam system if the density ratio R is higher than by about 100 times than that of reactor water. (Horiuchi, T.)

  2. Autogenous Metallic Pipe Leak Repair in Potable Water Systems.

    Science.gov (United States)

    Tang, Min; Triantafyllidou, Simoni; Edwards, Marc A

    2015-07-21

    Copper and iron pipes have a remarkable capability for autogenous repair (self-repair) of leaks in potable water systems. Field studies revealed exemplars that metallic pipe leaks caused by nails, rocks, and erosion corrosion autogenously repaired, as confirmed in the laboratory experiments. This work demonstrated that 100% (N = 26) of 150 μm leaks contacting representative bulk potable water in copper pipes sealed autogenously via formation of corrosion precipitates at 20-40 psi, pH 3.0-11.0, and with upward and downward leak orientations. Similar leaks in carbon steel pipes at 20 psi self-repaired at pH 5.5 and 8.5, but two leaks did not self-repair permanently at pH 11.0 suggesting that water chemistry may control the durability of materials that seal the leaks and therefore the permanence of repair. Larger 400 μm holes in copper pipes had much lower (0-33%) success of self-repair at pH 3.0-11.0, whereas all 400 μm holes in carbon steel pipes at 20 psi self-repaired at pH 4.0-11.0. Pressure tests indicated that some of the repairs created at 20-40 psi ambient pressure could withstand more than 100 psi without failure. Autogenous repair has implications for understanding patterns of pipe failures, extending the lifetime of decaying infrastructure, and developing new plumbing materials.

  3. An algorithm for leak point detection of underground pipelines

    International Nuclear Information System (INIS)

    Lee, Young Sup; Yoon, Dong Jin

    2004-01-01

    Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. However, the necessity of long-range detection of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretically analyzed and the wave velocity was confirmed with experiment. The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detection for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested, and a long-range detection has been achieved at real underground water pipelines longer than 300 m.

  4. An integrated leak detection system for the ALMR steam generator

    International Nuclear Information System (INIS)

    Dayal, Y.; Gaubatz, D.C.; Wong, K.K.; Greene, D.A.

    1995-01-01

    The steam generator (SG) of the Advanced Liquid Metal Reactor (ALMR) system serves as a heat exchanger between the shell side secondary loop hot liquid sodium and the tube side water/steam mixture. A leak in the tube will result in the injection of the higher pressure water/steam into the sodium and cause an exothermic sodium-water reaction. An initial small leak (less than 1 gm/sec) can escalate into an intermediate size leak in a relatively short time by self enlargement of the original flaw and by initiating leaks in neighboring tubes. If not stopped, complete rupture of one or more tubes can cause injection rates of thousands of gm/sec and result in the over pressurization of the secondary loop rupture disk and dumping of the sodium to relieve pressure. The down time associated with severe sodium-water reaction damage has great adverse economic consequence. An integrated leak detection system (ILDS) has been developed which utilizes both chemical and acoustic sensors for improved leak detection. The system provides SG leak status to the reactor operator and is reliable enough to trigger automatic control action to protect the SG. The ILDS chemical subsystem uses conventional in-sodium and cover gas hydrogen detectors and incorporates knowledge based effects due to process parameters for improved reliability. The ILDS acoustic subsystem uses an array of acoustic sensors and incorporates acoustic beamforming technology for highly reliable and accurate leak identification and location. The new ILDS combines the small leak detection capability of the chemical system with the reliability and rapid detection/location capability of the acoustic system to provide a significantly improved level of protection for the SG over a wide range of operation conditions. (author)

  5. Autologous Blood Pleurodesis In Patients With Persistent Air Leaks

    Directory of Open Access Journals (Sweden)

    Agkajanzadeh M

    2003-10-01

    Full Text Available Persistent air leaks occur after Spontaneous pneumothorax both primary and secondary, and after lungs trauma and lung surgeries are sever problems encountered chest surgeons with. Persistent air leak causes longer patients hospitalization."nMaterials and Methods: We used autologous blood pleurodesis in patients with persistent air leak for 30patients with more than 8 days air leaks, during a three years period 1377-1380 (1999-2002."nResults: The patients had 19 years up to 70 years old. Eight patients had thoracotomy and lobectomy and /or segmentectomies 6 with primary pneumothorax, 10 with secondary pneumothorax, and four with penetrated or blunt thoracic traumas. Blood was obtained from femoral or brachial veins and 70-150 mis. Injected in chest tubes. Chest bottle was first lied 80cm higher than body levels. After 24 hours repositioned in normal levels, and patients were supervised. Via chest tube we injected blood 70-100ml.for young patients, and 100-150 ml for older patients into intra pleural space. There were no clamped chest tubes. There were no pain, respiratory distress, fever, or cough in pleurodesized patients. The only patient's complaint was local pain in femoral vein or brachial vein because blood sampling and blood obtaining, although there was no local visible complication as hematoma or bleeding. After 48 hours in 24 patients air leak ceased. In six patients because persistent air leak autologous blood pleurodesis repeated, two patients after 48hours"nair leak ceased, remaining four patients underwent for thoracotomies, success rate"nwas 86.6%."nConclusion: According above success rate we suggest autologous blood pleurodesis in patients with persistent air leak is a reliable, effective, and no complicated procedure for persistent air leaks.

  6. Pumping and leak detection system of the HL-2A

    International Nuclear Information System (INIS)

    Cao Zeng; Xu Yunxian; Fu Weidong

    2001-01-01

    The pumping system is a combination of 8 turbomolecular pumps with three stages pumping for HL-2A vacuum vessel, a total effective pumping speed at the vessel of 12 m 3 ·s -1 for nitrogen. The leak detection of element and vessel is performed with inspiration, case of leak detection and two mass spectrometry. The total leak rate of vessel is bellow 1 x 10 -5 Pa ·m 3 ·s -1 . The base pressure is 1 x 10 -5 Pa

  7. Timing tests: automatic valve closure for tritium leaks

    International Nuclear Information System (INIS)

    Hanel, S.

    1976-01-01

    How fast can an automotive valve be closed after a tritium leak occurs in a system. Tests described found that a valve can be closed within fifteen seconds of leakage. In one practical example considered, this delay would limit loss of tritium from a plumbing leak in a tritium system to 1 1 / 4 g. The tests were made in a typical LLL air-flush hood in which a tritium handling system had been installed. Incidental observations suggest that further study be made of a possible leak-actuated recovery system for an entire tritium facility

  8. The pressure and leak tests in Atucha II

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This work deals with the pressure and leak tests of the containment sphere in the Atucha II Nuclear Power Plant's reactor building. This sphere is a metallic container, made in highly resistant steel plate, that is, built for providing the plant with a biological and structural barrier, which -in turn- provides safety and environmental protection. The applicable rules for these tests establish that the containment erection must be complete and in equivalent conditions to those that will prevail during the NPP operation. Particularly, pressure tests were carried out for assessing the structural condition of the sphere, while the leak test is aimed at the detection of tentative leaks [es

  9. Evaluation of primary coolant leaks and assessment of detection methods

    International Nuclear Information System (INIS)

    Cassette, P.; Giroux, C.; Roche, H.; Seveon, J.J.

    1984-11-01

    A review of French PWR situation concerning primary coolant leaks is presented, including a description of operating technical specifications, of the collecting system of primary coolant leakage into the containment and of the detection methods. It is mainly based on a compilation over three years, 1981 to 1983, of almost all occurred leaks, their natures, causes, consequences and methods used for their detection. By analysing these data it is possible to evaluate the efficiency of the primary coolant leak detection system and the problems raised by the compliance with the criteria defined in the operating technical specifications

  10. Evaluation of primary coolant leaks and assessment of detection methods

    International Nuclear Information System (INIS)

    Cassette, P.; Giroux, C.; Roche, H.; Seveon, J.J.

    1986-01-01

    A review of the French PWR situation concerning primary coolant leaks is presented, including a description of operating technical specifications, of the collecting system of primary coolant leakage into the containment and of the detection methods. It is mainly based on a compilation over three years, 1981 to 1983, of almost all actual leaks, their natures, causes, consequences and methods used for their detection. By analysing these data it is possible to evaluate the efficiency of the primary coolant leak detection system and the problems raised by compliance with the criteria defined in the operating technical specifications

  11. Evaluation of methods to leak test sealed radiation sources

    International Nuclear Information System (INIS)

    Arbeau, N.D.; Scott, C.K.

    1987-04-01

    The methods for the leak testing of sealed radiation sources were reviewed. One hundred and thirty-one equipment vendors were surveyed to identify commercially available leak test instruments. The equipment is summarized in tabular form by radiation type and detector type for easy reference. The radiation characteristics of the licensed sources were reviewed and summarized in a format that can be used to select the most suitable detection method. A test kit is proposed for use by inspectors when verifying a licensee's test procedures. The general elements of leak test procedures are discussed

  12. Acoustic Leak Detection under Micro and Small Water Steam Leaks into Sodium for a Protection of the SFR Steam Generator

    International Nuclear Information System (INIS)

    Kim, Tae-Joon; Jeong, Ji-Young; Kim, Jong-Man; Kim, Byung-Ho; Hahn, Do-Hee; Yugay, Valeriy S.

    2008-01-01

    The results of an experimental study of water in a sodium leak noise spectrum formation related with a leak noise attenuation and absorption, and at various rates of water into a sodium leak, smaller than 1.0 g/s, are presented. We focused on studying the micro leak dynamics with an increasing rate of water into sodium owing to a self-development from 0.005 till 0.27 g/s. Conditions and ranges for the existence of bubbling and jetting modes in a water steam outflow into circulating sodium through an injector device, for simulating a defect in a wall of a heat-transmitting tube of a sodium water steam generator were determined. On the basis of the experimental leak noise data the simple dependency of an acoustic signal level from the rate of a micro and small leak at different frequency bands is presented to understand the principal analysis for the development of an acoustic leak detection methodology used in a K- 600 steam generator, with the operational experiences for the noise analysis and measurements in BN-600

  13. Sodium and Proton Effects on Inward Proton Transport through Na/K Pumps

    Science.gov (United States)

    Mitchell, Travis J.; Zugarramurdi, Camila; Olivera, J. Fernando; Gatto, Craig; Artigas, Pablo

    2014-01-01

    The Na/K pump hydrolyzes ATP to export three intracellular Na (Nai) as it imports two extracellular K (Ko) across animal plasma membranes. Within the protein, two ion-binding sites (sites I and II) can reciprocally bind Na or K, but a third site (site III) exclusively binds Na in a voltage-dependent fashion. In the absence of Nao and Ko, the pump passively imports protons, generating an inward current (IH). To elucidate the mechanisms of IH, we used voltage-clamp techniques to investigate the [H]o, [Na]o, and voltage dependence of IH in Na/K pumps from ventricular myocytes and in ouabain-resistant pumps expressed in Xenopus oocytes. Lowering pHo revealed that Ho both activates IH (in a voltage-dependent manner) and inhibits it (in a voltage-independent manner) by binding to different sites. Nao effects depend on pHo; at pHo where no Ho inhibition is observed, Nao inhibits IH at all concentrations, but when applied at pHo that inhibits pump-mediated current, low [Na]o activates IH and high [Na]o inhibits it. Our results demonstrate that IH is a property inherent to Na/K pumps, not linked to the oocyte expression environment, explains differences in the characteristics of IH previously reported in the literature, and supports a model in which 1), protons leak through site III; 2), binding of two Na or two protons to sites I and II inhibits proton transport; and 3), pumps with mixed Na/proton occupancy of sites I and II remain permeable to protons. PMID:24940773

  14. Leak detection device on flange surface

    International Nuclear Information System (INIS)

    Hanai, Koi.

    1988-01-01

    Purpose: To improve the response to fine leakage thereby enabling to leakage detection at high sensitivity, by detecting the humidity by the use of an inert dry gas. Constitution: Annular grooves are coaxially engraved to a flange and an annular water channel groove is also engraved between each of the annular grooves. Dry nitrogen flown out is blown along the circumferential direction of the water channel grooves, turned there around and then released from the end of the pipeway. If there is any water leakage, the dry nitrogen absorbs leaked water to be wettened and then reach a humidity sensor. The sensor detects the humidity in the nitrogen and delivers an output into a signal processing circuit. The processing circuit judges the absence or presence of the leakage in accordance with the detected humidity to generate an alarm signal. The time required for the blown out dry nitrogen, which turn around the water channel groove and enter the sensor, is about several minutes and the device shows excellent response even for minute leakage. (Yoshino, Y.)

  15. Standard Practice for Dosimetry of Proton Beams for use in Radiation Effects Testing of Electronics

    International Nuclear Information System (INIS)

    McMahan, Margaret A.; Blackmore, Ewart; Cascio, Ethan W.; Castaneda, Carlos; von Przewoski, Barbara; Eisen, Harvey

    2008-01-01

    Representatives of facilities that routinely deliver protons for radiation effect testing are collaborating to establish a set of standard best practices for proton dosimetry. These best practices will be submitted to the ASTM International for adoption

  16. Standard Practice for Dosimetry of Proton Beams for use in Radiation Effects Testing of Electronics

    Energy Technology Data Exchange (ETDEWEB)

    McMahan, Margaret A.; Blackmore, Ewart; Cascio, Ethan W.; Castaneda, Carlos; von Przewoski, Barbara; Eisen, Harvey

    2008-07-25

    Representatives of facilities that routinely deliver protons for radiation effect testing are collaborating to establish a set of standard best practices for proton dosimetry. These best practices will be submitted to the ASTM International for adoption.

  17. Spherical proton emitters

    International Nuclear Information System (INIS)

    Berg, S.; Semmes, P.B.; Nazarewicz, W.

    1997-01-01

    Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society

  18. Proton therapy physics

    CERN Document Server

    2012-01-01

    Proton Therapy Physics goes beyond current books on proton therapy to provide an in-depth overview of the physics aspects of this radiation therapy modality, eliminating the need to dig through information scattered in the medical physics literature. After tracing the history of proton therapy, the book summarizes the atomic and nuclear physics background necessary for understanding proton interactions with tissue. It describes the physics of proton accelerators, the parameters of clinical proton beams, and the mechanisms to generate a conformal dose distribution in a patient. The text then covers detector systems and measuring techniques for reference dosimetry, outlines basic quality assurance and commissioning guidelines, and gives examples of Monte Carlo simulations in proton therapy. The book moves on to discussions of treatment planning for single- and multiple-field uniform doses, dose calculation concepts and algorithms, and precision and uncertainties for nonmoving and moving targets. It also exami...

  19. Proton solvation and proton transfer in chemical and electrochemical processes

    International Nuclear Information System (INIS)

    Lengyel, S.; Conway, B.E.

    1983-01-01

    This chapter examines the proton solvation and characterization of the H 3 O + ion, proton transfer in chemical ionization processes in solution, continuous proton transfer in conductance processes, and proton transfer in electrode processes. Topics considered include the condition of the proton in solution, the molecular structure of the H 3 O + ion, thermodynamics of proton solvation, overall hydration energy of the proton, hydration of H 3 O + , deuteron solvation, partial molal entropy and volume and the entropy of proton hydration, proton solvation in alcoholic solutions, analogies to electrons in semiconductors, continuous proton transfer in conductance, definition and phenomenology of the unusual mobility of the proton in solution, solvent structure changes in relation to anomalous proton mobility, the kinetics of the proton-transfer event, theories of abnormal proton conductance, and the general theory of the contribution of transfer reactions to overall transport processes

  20. Leak in spiral weld in a 16 inches gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Fazzini, Pablo G; Bona, Jeremias de [GIE S.A., Mar del Plata (Argentina); Otegui, Jose L [University of Mar del Plata (Argentina)

    2009-07-01

    This paper discusses a failure analysis after a leak in the spiral weld of a 16 inches natural gas pipeline, in service since 1974. The leak was the result of the coalescence of two different defects, on each surface of the pipe wall, located in the center of the inner cord of the helical DSAW weld. Fractographic and metallographic studies revealed that the leak was a combination of three conditions. During fabrication of the pipe, segregation in grain boundary grouped in mid weld. During service, these segregations underwent a process of selective galvanic corrosion. One of these volumetric defects coincided with a tubular pore in the outer weld. Pigging of the pipeline in 2005 for cleaning likely contributed to the increase of the leak flow, when eliminating corrosion product plugs. Although these defects are likely to repeat, fracture mechanics shows that a defect of this type is unlikely to cause a blowout. (author)

  1. Plasmonic leak-free focusing lens under radially polarized illumination

    International Nuclear Information System (INIS)

    Li, Xiaowei; Tan, Qiaofeng; Bai, Benfeng; Jin, Guofan

    2010-01-01

    A plasmonic leak-free focusing lens with two asymmetric concentric ring slits under radially polarized illumination is proposed. Each ring slit in the plasmonic lens is designed to generate surface plasmon polaritons (SPPs) with a relative initial phase controlled by the ring slit parameters. Through mutual interference of the SPPs with different phases excited by the two concentric ring slits at the output metal–dielectric interface, the field intensity towards the center of the focusing lens can be enhanced while that leaking to the counter-focus direction is effectively suppressed. The optimal parameters of the plasmonic leak-free lens are theoretically obtained by satisfying the above condition and its focusing performance is demonstrated by numerical simulation. Furthermore, a plasmonic leak-free lens with multiple double-slit groups is proposed and discussed, which exhibits a higher energy density at the focusing spot of the output interface

  2. Water leak detection in steam generator of SUPER PHENIX

    International Nuclear Information System (INIS)

    Brunet, M.; Garnaud, P.; Ghaleb, D.; Kong, N.

    1988-01-01

    With the intent of detecting water leaks inside steam generators, we developed a third system, called acoustic detector, to complement hydrogen detectors and rupture disks (burst disks). The role of the acoustic system is to enable rapid intervention in the event of a leak growing rapidly which could rupture neighbouring tubes. In such a case, the detectable flow rate of the leak varies from a few tens of g/s to a few hundred g/s. At the SUPER PHENIX, three teams work in [20-100 kHz] and CEA/STA* [50-300 kHz]. The simulation of water leaks in the steam generator by the argon injections performed to date at 50% of the rated power has shown promising results. An anomaly in the evolution of the background noise at more than 50% loading of one of the two instrumented steam generators would make difficult any extrapolation to full power behaviour. (author)

  3. The world is polluted with leaked cyber data

    CSIR Research Space (South Africa)

    Burke, Ivan D

    2017-10-01

    Full Text Available Data breaches are becoming more common and numerous every day, where huge amount of data (corporate and personal) are leaked more frequently than ever. Corporate responses to data breaches are insufficient, when commonly remediation is minimal...

  4. Analysis of Bracket Assembly for Portable Leak Detector Station

    International Nuclear Information System (INIS)

    ZIADA, H.H.

    1999-01-01

    This Supporting Document Presents Structural and Stress Analysis of a Portable Leak Detector Station for Tank Farms. The results show that the bracket assembly meets the requirements for dead load and natural phenomena hazards loads (seismic and wind)

  5. Leaking Underground Tanks in Rhode Island; LUSTs12

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — This dataset shows the location of storage tanks and associated piping used for petroleum and certain hazardous substances that have experienced leaks as determined...

  6. Helium leak testing of large pressure vessels or subassemblies

    International Nuclear Information System (INIS)

    Hopkins, J.S.; Valania, J.J.

    1977-01-01

    Specifications for pressure-vessel components [such as the intermediate heat exchangers (IHX)] for service in the liquid metal fast breeder reactor facilities require helium leak testing of pressure boundaries to very exacting standards. The experience of Foster Wheeler Energy Corporation (FWEC) in successfully leak-testing the IHX shells and bundle assemblies now installed in the Fast Flux Test Facility at Richland, WA is described. Vessels of a somewhat smaller size for the closed loop heat exchanger system in the Fast Flux Test Facility have also been fabricated and helium leak tested for integrity of the pressure boundary by FWEC. Specifications on future components call for helium leak testing of the tube to tubesheet welds of the intermediate heat exchangers

  7. Anastomotic leak after oesophagectomy and stent implantation: a systematic review

    Directory of Open Access Journals (Sweden)

    A.N. Kanatas

    2011-12-01

    Full Text Available Anastomotic leaks following oesophageal cancer resection have a high mortality. Stents have an established position in the palliation of dysphagia due to malignancy and in treating malignant perforation or fistula. They are increasingly used for benign conditions such as spontaneous oesophageal perforation with encouraging results. In this systematic review we examine the available evidence and attempt to define the role of stents in the management of oesophageal anastomotic leaks after resection for cancer. It is evident from the review that plastic- and metal-covered stents are an effective strategy for the treatment of anastomotic leaks. Vigilance is required as complications such as stent migration and incomplete sealing are not uncommon. Further clinical studies with greater methodological rigor in terms of sample size and study design may confirm that stents have an important contribution to make in the management of oesophageal anastomotic leak.

  8. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  9. Rio Vista gas leak study: Belleaire Gas Field, California

    International Nuclear Information System (INIS)

    Wilkey, P.L.

    1992-08-01

    The Rio Vista gas leak study evaluated methods for remotely sensing gas leaks from buried pipelines and developed methods to elucidate methane transport and microbial oxidation in soils. Remote-sensing methods were evaluated by singing gas leaks along an abandoned Pacific Gas and Electric (PG ampersand E) gas field collection line in northern California and applying surface-based and airborne remote-sensing techniques in the field, including thermal imaging, laser imaging, and multispectral imagery. The remote-sensing techniques exhibited limitations in range and in their ability to correlate with ground truth data. To elucidate methane transport and microbial oxidation in soils, a study of a controlled leak permitted field testing of methods so that such processes could be monitored and evaluated. Monitoring and evaluation techniques included (1) field measurement of soil-gas concentrations, temperatures, and pressures; (2) laboratory measurement of soil physical/chemical properties and activity of methane-oxidizing microorganisms by means of field samples; and (3) development of a preliminary numerical analysis technique for combined soil-gas transport/methane oxidation. Soil-gas concentrations at various depths responded rapidly to the high rate of gas leakage. The number of methane-oxidizing microorganisms in site soils rapidly increased when the gas leak was initiated and decreased after the leak was terminated. The preliminary field, laboratory, and numerical analysis techniques tested for this study of a controlled gas leak could be successfully applied to future studies of gas leaks. Because soil-gas movement is rapid and temporally variable, the use of several complementary techniques that permit generalization of site-specific results is favored

  10. Space Shuttle RCS Oxidizer Leak Repair for STS-26

    Science.gov (United States)

    Delventhal, R. A.; Faget, N. M.

    1989-01-01

    Following propellant loading of the Space Shuttle's reaction control system (RCS) for mission STS 26, an oxidizer leak was detected in the left orbital maneuvering system (OMS) pod, where the RCS is located. Subsequent investigation determined that the leak was isolated at a mechanical Dynatube fitting near the RCS nitrogen tetroxide tank. An intense effort was initiated to design, fabricate, and qualify a sealing device to stop the oxidizer leak externally so that the Space Shuttle launch could proceed. It was discovered that sealing devices called clamshells were widely used throughout the petrochemical and power generation industries to stop leaks developed in large diameter pipes which carry steam or other hazardous fluids. These clamshells are available in different diameters and strengths and are placed around the pipe at the location of the leak. A sealing compound is then injected under high pressure into the clamshell to stop the leak. This technology was scaled down and applied to the problem of stopping the leak on the Orbiter, which was on a half-inch diameter line in a nearly inaccessible location. Many obstacles had to be overcome such as determining that the sealing material would be compatible with the nitrogen tetroxide and ensuring that the clamshell would actually fit around the Dynatube fitting without interfering with other lines which were in close proximity. The effort at the NASA Johnson Space Center included materials compatibility testing of several sealants, design of a clamshell to fit in the confined compartment, and manufacture and qualification of the flight hardware. A clamshell was successfully placed around the Dynatube fitting on the Orbiter and the oxidizer leak was terminated. Then it was decided to apply this technology further and design clamshells for other mechanical fittings onboard the Orbiter and develop sealing compounds which will be compatible with fuels such as monomethyl hydrazine (MMH). The potential exists for

  11. Tig welding produces leak-proof joints for nuclear application

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    A pulsed welding apparatus using a Hobart Cyber-tig power source with programmed pulsed current has been developed to produce leak-free welds required for a new hermetically sealed leak-free valve for use in nuclear power plants. Advantages of the technique are precise control over travel speed and filler metal addition allowing the weld to be repeated with precision. (R.A.)

  12. Method for fuel element leak detection in pressurized water reactors

    International Nuclear Information System (INIS)

    Kunze, U.

    1983-01-01

    The method is aimed at detecting fuel element leaks during reactor operation. It is based on neutron flux measurements at many points in the core, using at least two detectors at a time. The detectors must be arranged in the direction of the coolant flow. Values obtained from periodic measurements are compared with threshold values. The location of fuel element leaks is determined from those values exceeding the threshold of individual detectors

  13. EBR-II water-to-sodium leak detection system

    International Nuclear Information System (INIS)

    Wrightson, M.M.; McKinley, K.; Ruther, W.E.; Holmes, J.T.

    1976-01-01

    The water-to-sodium leak detection system installed at EBR-II in April, 1975, is described in detail. Topics covered include operational characteristics, maintenance problems, alarm functions, background hydrogen level data, and future plans for refinements to the system. Particular emphasis is given to the failures of eight of the ten leak detectors due to sodium-to-vacuum leakage, and the program anticipated for complete recovery of the system

  14. Identification of sewage leaks by active remote-sensing methods

    Science.gov (United States)

    Goldshleger, Naftaly; Basson, Uri

    2016-04-01

    The increasing length of sewage pipelines, and concomitant risk of leaks due to urban and industrial growth and development is exposing the surrounding land to contamination risk and environmental harm. It is therefore important to locate such leaks in a timely manner, to minimize the damage. Advances in active remote sensing Ground Penetrating Radar (GPR) and Frequency Domain Electromagnetic (FDEM) technologies was used to identify leaking potentially responsible for pollution and to identify minor spills before they cause widespread damage. This study focused on the development of these electromagnetic methods to replace conventional acoustic methods for the identification of leaks along sewage pipes. Electromagnetic methods provide an additional advantage in that they allow mapping of the fluid-transport system in the subsurface. Leak-detection systems using GPR and FDEM are not limited to large amounts of water, but enable detecting leaks of tens of liters per hour, because they can locate increases in environmental moisture content of only a few percentage along the pipes. The importance and uniqueness of this research lies in the development of practical tools to provide a snapshot and monitoring of the spatial changes in soil moisture content up to depths of about 3-4 m, in open and paved areas, at relatively low cost, in real time or close to real time. Spatial measurements performed using GPR and FDEM systems allow monitoring many tens of thousands of measurement points per hectare, thus providing a picture of the spatial situation along pipelines and the surrounding. The main purpose of this study was to develop a method for detecting sewage leaks using the above-proposed geophysical methods, since their contaminants can severely affect public health. We focused on identifying, locating and characterizing such leaks in sewage pipes in residential and industrial areas.

  15. FUZZY INFERENCE BASED LEAK ESTIMATION IN WATER PIPELINES SYSTEM

    OpenAIRE

    N. Lavanya; G. Anand; S. Srinivasan

    2015-01-01

    Pipeline networks are the most widely used mode for transporting fluids and gases around the world. Leakage in this pipeline causes harmful effects when the flowing fluid/gas is hazardous. Hence the detection of leak becomes essential to avoid/minimize such undesirable effects. This paper presents the leak detection by spectral analysis methods in a laboratory pipeline system. Transient in the pressure signal in the pipeline is created by opening and closing the exit valve. These pressure var...

  16. Isotopic method of leaks detection in oil pipelines

    International Nuclear Information System (INIS)

    Listwam, W.; Mottl, J.

    1974-01-01

    Isotopic method of leaks detection in oil pipelines of diameter 200-800 mm is described. Tracer is injected into pipeline in the form of CH 3 Br 82 . After few hours one or two detectors are passed through pipeline to detect leaks. Detector set consists of scintillation radiometer with Na I/Tl crystal, electronic blecks with one-channel analyzer, recorder and storage batteries. Detector set is built on integrated circuits. (Z.M.)

  17. Lipophilic triphenylphosphonium cations inhibit mitochondrial electron transport chain and induce mitochondrial proton leak.

    Directory of Open Access Journals (Sweden)

    Jan Trnka

    Full Text Available The lipophilic positively charged moiety of triphenylphosphonium (TPP+ has been used to target a range of biologically active compounds including antioxidants, spin-traps and other probes into mitochondria. The moiety itself, while often considered biologically inert, appears to influence mitochondrial metabolism.We used the Seahorse XF flux analyzer to measure the effect of a range of alkylTPP+ on cellular respiration and further analyzed their effect on mitochondrial membrane potential and the activity of respiratory complexes. We found that the ability of alkylTPP+ to inhibit the respiratory chain and decrease the mitochondrial membrane potential increases with the length of the alkyl chain suggesting that hydrophobicity is an important determinant of toxicity.More hydrophobic TPP+ derivatives can be expected to have a negative impact on mitochondrial membrane potential and respiratory chain activity in addition to the effect of the biologically active moiety attached to them. Using shorter linker chains or adding hydrophilic functional groups may provide a means to decrease this negative effect.

  18. Different effects of guanine nucleotides (GDP and GTP) on protein-mediated mitochondrial proton leak.

    Science.gov (United States)

    Woyda-Ploszczyca, Andrzej M; Jarmuszkiewicz, Wieslawa

    2014-01-01

    In this study, we compared the influence of GDP and GTP on isolated mitochondria respiring under conditions favoring oxidative phosphorylation (OXPHOS) and under conditions excluding this process, i.e., in the presence of carboxyatractyloside, an adenine nucleotide translocase inhibitor, and/or oligomycin, an FOF1-ATP synthase inhibitor. Using mitochondria isolated from rat kidney and human endothelial cells, we found that the action of GDP and GTP can differ diametrically depending on the conditions. Namely, under conditions favoring OXPHOS, both in the absence and presence of linoleic acid, an activator of uncoupling proteins (UCPs), the addition of 1 mM GDP resulted in the state 4 (non-phosphorylating respiration)-state 3 (phosphorylating respiration) transition, which is characteristic of ADP oxidative phosphorylation. In contrast, the addition of 1 mM GTP resulted in a decrease in the respiratory rate and an increase in the membrane potential, which is characteristic of UCP inhibition. The stimulatory effect of GDP, but not GTP, was also observed in inside-out submitochondrial particles prepared from rat kidney mitochondria. However, the effects of GDP and GTP were more similar in the presence of OXPHOS inhibitors. The importance of these observations in connection with the action of UCPs, adenine nucleotide translocase (or other carboxyatractyloside-sensitive carriers), carboxyatractyloside- and purine nucleotide-insensitive carriers, as well as nucleoside-diphosphate kinase (NDPK) are considered. Because the measurements favoring oxidative phosphorylation better reflect in vivo conditions, our study strongly supports the idea that GDP cannot be considered a significant physiological inhibitor of UCP. Moreover, it appears that, under native conditions, GTP functions as a more efficient UCP inhibitor than GDP and ATP.

  19. Operational tank leak detection and minimization during retrieval

    International Nuclear Information System (INIS)

    Hertzel, J.S.

    1996-03-01

    This report evaluates the activities associated with the retrieval of wastes from the single-shell tanks proposed under the initial Single-Shell Tank Retrieval System. This report focuses on minimizing leakage during retrieval by using effective leak detection and mitigating actions. After reviewing the historical data available on single-shell leakage, and evaluating current leak detection technology, this report concludes that the only currently available leak detection method which can function within the most probable leakage range is the mass balance system. If utilized after each sluicing campaign, this method should allow detection at a leakage value well below the leakage value where significant health effects occur which is calculated for each tank. Furthermore, this report concludes that the planned sequence or sluicing activities will serve to further minimize the probability and volume of leaks by keeping liquid away from areas with the greatest potential for leaking. Finally, this report identifies a series of operational responses which when used in conjunction with the recommended sluicing sequence and leak detection methods will minimize worker exposure and environmental safety health risks

  20. Leak test fixture and method for using same

    Science.gov (United States)

    Hawk, Lawrence S.

    1976-01-01

    A method and apparatus are provided which are especially useful for leak testing seams such as an end closure or joint in an article. The test does not require an enclosed pressurized volume within the article or joint section to be leak checked. A flexible impervious membrane is disposed over an area of the seamed surfaces to be leak checked and sealed around the outer edges. A preselected vacuum is applied through an opening in the membrane to evacuate the area between the membrane and the surface being leak checked to essentially collapse the membrane to conform to the article surface or joined adjacent surfaces. A pressure differential is concentrated at the seam bounded by the membrane and only the seam experiences a pressure differential as air or helium molecules are drawn into the vacuum system through a leak in the seam. A helium detector may be placed in a vacuum exhaust line from the membrane to detect the helium. Alternatively, the vacuum system may be isolated at a preselected pressure and leaks may be detected by a subsequent pressure increase in the vacuum system.

  1. Gas Leak Detection by Dilution of Atmospheric Oxygen

    Directory of Open Access Journals (Sweden)

    Armin Lambrecht

    2017-12-01

    Full Text Available Gas leak detection is an important issue in infrastructure monitoring and industrial production. In this context, infrared (IR absorption spectroscopy is a major measurement method. It can be applied in an extractive or remote detection scheme. Tunable laser spectroscopy (TLS instruments are able to detect CH4 leaks with column densities below 10 ppm·m from a distance of 30 m in less than a second. However, leak detection of non-IR absorbing gases such as N2 is not possible in this manner. Due to the fact that any leaking gas displaces or dilutes the surrounding background gas, an indirect detection is still possible. It is shown by sensitive TLS measurements of the ambient background concentration of O2 that N2 leaks can be localized with extractive and standoff methods for distances below 1 m. Minimum leak rates of 0.1 mbar·L/s were determined. Flow simulations confirm that the leakage gas typically effuses in a narrow jet. The sensitivity is mainly determined by ambient flow conditions. Compared to TLS detection of CH4 at 1651 nm, the indirect method using O2 at 761 nm is experimentally found to be less sensitive by a factor of 100. However, the well-established TLS of O2 may become a universal tool for rapid leakage screening of vessels that contain unknown or inexpensive gases, such as N2.

  2. Depressurization as a means of leak checking large vacuum vessels

    International Nuclear Information System (INIS)

    Callis, R.W.; Langhorn, A.; Petersen, P.I.; Ward, C.; Wesley, J.

    1985-01-01

    A common problem associated with large vacuum vessels used in magnetic confinement fusion experiments is that leak checking is hampered by the inaccessibility to most of the vacuum vessel surface. This inaccessibility is caused by the close proximity of magnetic coils, diagnostics and, for those vessels that are baked, the need to completely surround the vessel with a thermal insulation blanket. These obstructions reduce the effectiveness of the standard leak checking method of using a mass spectrometer and spraying a search gas such as helium on the vessel exterior. Even when the presence of helium is detected, its entry point into the vessel cannot always be pinpointed. This paper will describe a method of overcoming this problem. By slightly depressurizing the vessel, an influx of helium through the leak is created. The leak site can then be identified by personnel within the vessel using standard sniffing procedures. There are two conditions which make this method of leak checking practical. First, the vessel need only be depressurized 2 psi, thus allowing personnel inside to perform the sniffing operation. Second, the sniffing probe used (Leybold--Heraus ''Quick Test'') could detect a change in helium concentration as small as 100 ppb, which allows for faster scanning of the vessel inferior. Use of this technique to find an elusive 10 -3 Torrxl/s leak in the Doublet III tokamak vacuum vessel will be presented

  3. Measurement of Submerged Oil/Gas Leaks using ROV Video

    Science.gov (United States)

    Shaffer, Franklin; de Vera, Giorgio; Lee, Kenneth; Savas, Ömer

    2013-11-01

    Drilling for oil or gas in the Gulf of Mexico is increasing rapidly at depths up to three miles. The National Commission on the Deepwater Horizon Oil Leak concluded that inaccurate estimates of the leak rate from the Deepwater Horizon caused an inadequate response and attempts to cap the leak to fail. The first response to a submerged oil/gas leak will be to send a Remotely Operated Vehicle (ROV) down to view the leak. During the response to the Deepwater Horizon crisis, the authors Savas and Shaffer were members of the Flow Rate Technical Group's Plume Team who used ROV video to develop the FRTG's first official estimates of the oil leak rate. Savas and Shaffer developed an approach using the larger, faster jet features (e.g., turbulent eddies, vortices, entrained particles) in the near-field developing zone to measure discharge rates. The authors have since used the Berkeley Tow Tank to test this approach on submerged dye-colored water jets and compressed air jets. Image Correlation Velocimetry has been applied to measure the velocity of visible features. Results from tests in the Berkeley Tow Tank and submerged oil jets in the OHMSETT facility will be presented.

  4. Occurrence of occult CSF leaks during standard FESS procedures.

    Science.gov (United States)

    Bucher, S; Kugler, A; Probst, E; Epprecht, L; Stadler, R S; Holzmann, D; Soyka, M B

    2018-03-18

    To determine the incidence of occult cerebrospinal fluid leaks (CSF) after functional endoscopic sinus surgery (FESS) and to evaluate the diagnostic performance of beta2-transferrin in blood-contaminated conditions. Prospective cohort study. An analysis of 57 intraoperative samples using hydrogel 6 beta2-transferrin assay after FESS was undertaken. In case of CSF positive samples and continuing rhinorrhea, reanalysis after more than 1 year was conducted. In-vivo analysis of a primary spontaneous CSF leak sample took place to verify difficulties in detecting beta2-transferrin in blood-contaminated settings. Own titrations were performed to evaluate detection limits of CSF by beta2-transferrin and beta-trace protein assays in these settings. An incidence of 13% for occult CSF leaks after FESS was found. In blood-contaminated conditions, routine beta2-transferrin assays showed low sensitivity. In over 1 year follow-up, all samples were negative for CSF and none of them developed clinical relevant CSF leaks or meningitis. Occult and clinically irrelevant CSF leaks do occur in a significant proportion of patients during and shortly after FESS. Intra- and postoperatively, routine beta2-transferrin assays show low sensitivity. They should not be used in these settings. The clinical course of patients with occult CSF leaks indicated possibility of an uneventful follow-up.

  5. Detection of pressure tube leaks relying on moisture beetles only

    International Nuclear Information System (INIS)

    Kenchington, J.M.; Choi, A.; Jin, Y.

    2004-01-01

    A major decision was made for Pickering NGS A Annulus Gas System (ACS) that detection of a pressure tube (PT) leak should be achieved by using only moisture beetles and that dew point monitors would provide 'early warning' without status to shut down the reactor. Experience with Unit 3 has shown that dew point monitoring of pressure tube leaks was particularly subject to gas leaks and surface adsorption effects. Unit 4 was the first one to be converted during the full scale pressure tube replacement programme. Because of the fundamental change in design philosophy, moisture injection tests were carried out during commissioning to demonstrate that performance matched design. In particular it was necessary to show that leak before break (LBB) would be achieved if a leak occurred in the limiting string. Units 1 and 3 have since been converted. No decision has been taken to convert Pickering B units as gas leaks are small and no significant adsorption effects are anticipated. Hence dew point monitoring will not be impaired. (author)

  6. Influence of Crack Morphology on Leak Before Break Margins

    International Nuclear Information System (INIS)

    Weilin Zang

    2007-11-01

    The purpose of the project is to evaluate the deterministic LBB-margins for different pipe systems in a Swedish PWR-plant and using different crack morphology parameters. Results: - The influence of crack morphology on Leak Before Break (LBB) margins is studied. The subject of the report is a number of LBB-submittals to SKI where deterministic LBB-margins are reported. These submittals typically uses a surface roughness of 0.0762 mm (300 microinch) and number of turns equal to zero and an in-house code for the leak rate evaluations. The present report has shown that these conditions give the largest LBB-margins both in terms of the quotient between the critical crack length and the leakage crack size and for the leak rate margin. - Crack morphology parameters have a strong influence on the leak rate evaluations. Using the SQUIRT code and more recent recommendations for crack morphology parameters, it is shown that in many cases the evaluated margins, using 1 gpm as the reference leak rate detection limit, are below the safety factor of 2 on crack size and 10 on leak rate, which is generally required for LBB approval. - The effect of including weld residual stresses on the LBB margins is also investigated. It is shown that for the two examples studied, weld residual stresses were important for the small diameter thin wall pipe whereas it was negligible for the large diameter thick wall pipe which had a self-balanced weld residual stress distribution

  7. FUZZY INFERENCE BASED LEAK ESTIMATION IN WATER PIPELINES SYSTEM

    Directory of Open Access Journals (Sweden)

    N. Lavanya

    2015-01-01

    Full Text Available Pipeline networks are the most widely used mode for transporting fluids and gases around the world. Leakage in this pipeline causes harmful effects when the flowing fluid/gas is hazardous. Hence the detection of leak becomes essential to avoid/minimize such undesirable effects. This paper presents the leak detection by spectral analysis methods in a laboratory pipeline system. Transient in the pressure signal in the pipeline is created by opening and closing the exit valve. These pressure variations are captured and power spectrum is obtained by using Fast Fourier Transform (FFT method and Filter Diagonalization Method (FDM. The leaks at various positions are simulated and located using these methods and the results are compared. In order to determine the quantity of leak a 2 × 1 fuzzy inference system is created using the upstream and downstream pressure as input and the leak size as the output. Thus a complete leak detection, localization and quantification are done by using only the pressure variations in the pipeline.

  8. Local Leak Detection and Health Monitoring of Pressurized Tanks

    Science.gov (United States)

    Polzin, Kurt; Witherow, William; Korman, Valentin; Sinko, John; Hendrickson, Adam

    2011-01-01

    An optical gas-detection sensor safely monitors pressurized systems (such as cryogenic tanks) and distribution systems for leaks. This sensor system is a fiber-coupled, solid optical body interferometer that allows for the miniaturized sensing element of the device to be placed in the smallest of recesses, and measures a wide range of gas species and densities (leaks). The deflection of the fringe pattern is detected and recorded to yield the time-varying gas density in the gap. This technology can be used by manufacturers or storage facilities with toxic, hazardous, or explosive gases. The approach is to monitor the change in the index of refraction associated with low-level gas leaks into a vacuum environment. The completion of this work will provide NASA with an enabling capability to detect gas system leaks in space, and to verify that pressurized systems are in a safe (i.e. non-leaking) condition during manned docking and transit operations. By recording the output of the sensor, a time-history of the leak can be constructed to indicate its severity. Project risk is mitigated by having several interferometric geometries and detection techniques available, each potentially leveraging hardware and lessons learned to enhance detectability.

  9. 40 CFR 63.1086 - How must I monitor for leaks to cooling water?

    Science.gov (United States)

    2010-07-01

    ... monitor for leaks to cooling water? You must monitor for leaks to cooling water by monitoring each heat... system so that the cooling water flow rate is 51,031 liters per minute or less so that a leak of 3.06 kg... detected a leak. (b) Individual heat exchangers. Monitor the cooling water at the entrance and exit of each...

  10. 40 CFR 63.1087 - What actions must I take if a leak is detected?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false What actions must I take if a leak is... leak is detected? If a leak is detected, you must comply with the requirements in paragraphs (a) and (b) of this section unless repair is delayed according to § 63.1088. (a) Repair the leak as soon as...

  11. The pump and leak steady-state concept with a variety of regulated leak pathways

    DEFF Research Database (Denmark)

    Hoffmann, E K

    2001-01-01

    . This had a major influence on my later description of a swelling-activated Cl- conductance. (ii) The pump-leak steady-state concept for cell volume control was introduced by Krogh in 1946, but it was developed in detail by Leaf and Ussing in 1959. This concept was the basis for me and others, when we later...... found that the passive ion leaks play an active role in cell volume control. (iii) The use of isotopes and Ussing's famous flux ratio equation provided an ingenious instrument for distinguishing the various transport routes. We used this to identify the Na,K,2Cl cotransport system as accounting...... for maintaining a [Cl-]i in the EATC far above thermodynamic equilibrium, as well as accounting for the ion uptake during a regulatory volume increase (RVI) in EATC, similar to what Ussing had found in frog skin. (iv) Short-circuit current setup in the Ussing chamber is still used in laboratories around the world...

  12. Active acoustic leak detection for LMFBR steam generators. Pt. 7. Potential for small leak detection

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Yoshida, Kazuo

    1998-01-01

    In order to prevent the expansion of tube damage and to maintain structural integrity in the steam generators (SGs) of fast breeder reactors (FBR), it is necessary to detect precisely and immediately the leakage of water from heat transfer tubes. Therefore, an active acoustic method, which detects the sound attenuation due to bubbles generated in the sodium-water reactions, is being developed. Previous studies have revealed that the active acoustic method can detect bubbles of 10 l/s (equivalence water leak rate about 10 g/s) within 10 seconds in practical steam generators. In order to prevent the expansion of damage to neighboring tubes, however, it is necessary to detect smaller leakage of water from heat transfer tubes. In this study, in order to evaluate the detection sensitivity of the active method, the signal processing methods for emitter and receiver sound and the detection method for leakage within 1 g/s are investigated experimentally, using an SG full-sector model that simulates the actual SGs. A typical result shows that detection of 0.4 l/s air bubbles (equivalent water leak rate about 0.4 g/s) takes about 80 seconds, which is shorter than the propagation time of damage to neighboring tubes. (author)

  13. Leak before break piping evaluation diagram

    International Nuclear Information System (INIS)

    Fabi, R.J.; Peck, D.A.

    1994-01-01

    Traditionally Leak Before Break (LBB) has been applied to the evaluation of piping in existing nuclear plants. This paper presents a simple method for evaluating piping systems for LBB during the design process. This method produces a piping evaluation diagram (PED) which defines the LBB requirements to the piping designer for use during the design process. Several sets of LBB analyses are performed for each different pipe size and material considered in the LBB application. The results of this method are independent of the actual pipe routing. Two complete LBB evaluations are performed to determine the maximum allowable stability load, one evaluation for a low normal operating load, and the other evaluation for a high normal operating load. These normal operating loads span the typical loads for the particular system being evaluated. In developing the allowable loads, the appropriate LBB margins are included in the PED preparation. The resulting LBB solutions are plotted as a set of allowable curves for the maximum design basis load, such is the seismic load versus the normal operating load. Since the required margins are already accounted for in the LBB PED, the piping designer can use the diagram directly with the results of the piping analysis and determine immediately if the current piping arrangement passes LBB. Since the LBB PED is independent of pipe routing, changes to the piping system can be evaluated using the existing PED. For a particular application, all that remains is to confirm that the actual materials and pipe sizes assumed in creating the particular design are built into the plant

  14. Location estimation method of steam leak in pipeline using leakage area analysis

    International Nuclear Information System (INIS)

    Kim, Se Oh; Jeon, Hyeong Seop; Son, Ki Sung; Park, Jong Won

    2016-01-01

    It is important to have a pipeline leak-detection system that determines the presence of a leak and quickly identifies its location. Current leak detection methods use a acoustic emission sensors, microphone arrays, and camera images. Recently, many researchers have been focusing on using cameras for detecting leaks. The advantage of this method is that it can survey a wide area and monitor a pipeline over a long distance. However, conventional methods using camera monitoring are unable to target an exact leak location. In this paper, we propose a method of detecting leak locations using leak-detection results combined with multi-frame analysis. The proposed method is verified by experiment

  15. Location estimation method of steam leak in pipeline using leakage area analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Se Oh; Jeon, Hyeong Seop; Son, Ki Sung [Sae An Engineering Corp., Seoul (Korea, Republic of); Park, Jong Won [Dept. of Information Communications Engineering, Chungnam National University, Daejeon (Korea, Republic of)

    2016-10-15

    It is important to have a pipeline leak-detection system that determines the presence of a leak and quickly identifies its location. Current leak detection methods use a acoustic emission sensors, microphone arrays, and camera images. Recently, many researchers have been focusing on using cameras for detecting leaks. The advantage of this method is that it can survey a wide area and monitor a pipeline over a long distance. However, conventional methods using camera monitoring are unable to target an exact leak location. In this paper, we propose a method of detecting leak locations using leak-detection results combined with multi-frame analysis. The proposed method is verified by experiment.

  16. Engineering study of tank leaks related to hydraulic retrieval of sludge from tank 241-C-106

    International Nuclear Information System (INIS)

    Lowe, S.S.; Carlos, W.C.; Irwin, J.J.; Khaleel, R.; Kline, N.W.; Ludowise, J.D.; Marusich, R.M.; Rittman, P.D.

    1993-01-01

    This study evaluates hydraulic retrieval (sluicing) of the waste in single-shell tank 241-C-106 with respect to the likelihood of tank leaks, gross volumes of potential leaks, and their consequences. A description of hydraulic retrieval is developed to establish a baseline for the study. Leak models are developed based on postulated leak mechanisms to estimate the amount of waste that could potentially leak while sluicing. Transport models describe the movement of the waste constituents in the surrounding soil and groundwater after a leak occurs. Environmental impact and risk associated with tank leaks are evaluated. Transport of leaked material to the groundwater is found to be dependent on the rate of recharge of moisture in the soil for moderate-sized leaks. Providing a cover over the tank and surrounding area would eliminate the recharge. The bulk of any leaked material would remain in the vicinity of the tank for remedial action

  17. Analysis on signal properties due to concurrent leaks at two points in water supply pipelines

    International Nuclear Information System (INIS)

    Lee, Young Sup

    2015-01-01

    Intelligent leak detection is an essential component of a underground water supply pipeline network such as a smart water grid system. In this network, numerous leak detection sensors are needed to cover all of the pipelines in a specific area installed at specific regular distances. It is also necessary to determine the existence of any leaks and estimate its location within a short time after it occurs. In this study, the leak signal properties and feasibility of leak location detection were investigated when concurrent leaks occurred at two points in a pipeline. The straight distance between the two leak sensors in the 100A sized cast-iron pipeline was 315.6 m, and their signals were measured with one leak and two concurrent leaks. Each leak location was described after analyzing the frequency properties and cross-correlation of the measured signals.

  18. Analysis on signal properties due to concurrent leaks at two points in water supply pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Sup [Dept. of Embedded Systems Engineering, Incheon National University, Incheon (Korea, Republic of)

    2015-02-15

    Intelligent leak detection is an essential component of a underground water supply pipeline network such as a smart water grid system. In this network, numerous leak detection sensors are needed to cover all of the pipelines in a specific area installed at specific regular distances. It is also necessary to determine the existence of any leaks and estimate its location within a short time after it occurs. In this study, the leak signal properties and feasibility of leak location detection were investigated when concurrent leaks occurred at two points in a pipeline. The straight distance between the two leak sensors in the 100A sized cast-iron pipeline was 315.6 m, and their signals were measured with one leak and two concurrent leaks. Each leak location was described after analyzing the frequency properties and cross-correlation of the measured signals.

  19. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  20. TACIS 91: Application of leak-before-break concept in VVER 440-230

    Energy Technology Data Exchange (ETDEWEB)

    Bartholome, G.; Faidy, C.; Franco, C. [and others

    1997-04-01

    The applicability of the leak-before-break (LBB) concept for primary piping in the first generation of WWER type plants in Russia is investigated. The procedures for LBB behavior used in France and Germany are applied, and the evaluation is discussed within the framework of the European Technical Assistance for the Community of Independent States (TACIS) project. Emphasis is placed on experimental validation of national and international engineering practice for evaluating and optimizing existing installations. Design criteria of WWER plants are compared to western standard design.

  1. Innovative Acoustic Sensor Technologies for Leak Detection in Challenging Pipe Types

    Science.gov (United States)

    2016-12-30

    the level of water leakage within the water distribution system. Table 7-3. Cost Summary for LeakFinderRT LeakFinderRT Leak Detection Cost...and to limit the drawdown of local water supplies. Implementation of improved leak detection technologies and the timely repair of water mains will...6-5. Water -filled Valve Box in Vicinity of Leak Detected by ZoneScan Alpha System

  2. Sodium fire tests for investigating the sodium leak in Monju

    International Nuclear Information System (INIS)

    Seino, Hiroshi; Miyahara, Shinya; Miyake, Osamu; Tanabe, Hiromi

    1996-01-01

    As a part of the work for investigating the sodium leak accident which occurred in Monju on December 8, 1995, three tests, (1) sodium leak test, (2) sodium fire test-I, and (3) sodium fire test-II, were carried out at OEC/PNC. Main objectives of these tests are to confirm leak and burning behavior of sodium from the damaged thermometer, and effects of the sodium fire on integrity of the surrounding structure, etc. The main conclusions obtained from the tests are shown as below. 1) Average sodium leak rate obtained from the sodium leak test was about 50 g/sec. This was equivalent to the value estimated from level change in the sodium overflow tank in the Monju accident. 2) Observation from video cameras in the sodium fire tests revealed that in early stages of sodium leak, sodium dropped down out of the flexible tube of thermometer in drips. This dripping and burning were expanded in range as sodium splashed on the duct. 3) Though, in the sodium fire test-I, there was a decrease of about 1 mm at a thickness of the burning pan in the vicinity in just under in the leak point, there were completely no crack and failure. In the meantime, in the sodium fire test-II the six open holes were found in the floor liner. By this liner failure, the reaction between sodium and concrete might take place. At present, while the detailed evaluation on the sodium fire test-II has been mainly carried out, the investigation for clarifying the cause of the liner failure has been also carried out. (author)

  3. Proton Fast Ignition

    International Nuclear Information System (INIS)

    Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

    2006-04-01

    Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

  4. A survey of existing and emerging technologies for external detection of liquid leaks at the Hanford Site

    International Nuclear Information System (INIS)

    Lewis, R.E.; Teel, S.S.

    1994-10-01

    During the history of the Hanford Site, many structures were built that stored and transported liquids used for the production mission; some of these structures are still active. Active structures include underground storage tanks retention basins, and pipes and pipelines. Many of the liquids stored and transported in these structures are potentially hazardous to human health and the environment. Any leakage of liquids from active structures, has the added potential to mobilize contaminants in the unsaturated zone. Therefore, it is beneficial to monitor these structures for leaks. The purpose of tills report is to catalog existing and emerging technologies that have potential for the external monitoring of liquid leaks. The report will focus primarily on the needs at the Hanford Site tank farms that are located in the 200 Areas, but will also be relevant to other Hanford Site facilities. Leak detection systems, both external and internal, are currently used at some Hanford facilities. This report focuses on the detection of leaks as they migrate into the soils surrounding the facilities

  5. Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model.

    Science.gov (United States)

    Tracy, Mark B; Shah, Dharmesh; Hinder, Murray; Klimek, Jan; Marceau, James; Wright, Audrey

    2014-05-01

    To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants. Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak. The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p mask leak of 6.8% (p mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  6. Mechanical experiments on the superplastic material ALNOVI-1, including leak information

    International Nuclear Information System (INIS)

    Snippe, Q.H.C.; Meinders, T.

    2011-01-01

    forming process. Such a pressure postpones the nucleation and growth of internal cavities, which means that higher plastic strains can be reached before failure. Results from these experiments showed that at higher hydrostatic pressures, higher bulges were made. All these bulges were leak tested, showing also that higher hydrostatic pressures lead to a lower void volume fraction at higher hydrostatic pressures, since these bulges were more leak tight at the same bulge height than bulges made without the application of this pressure. This article describes the setup and results of the uniaxial (tensile) and biaxial (bulging) experiments on the superplastic aluminium ALNOVI-1.

  7. Full scale leak test of the MEGAPIE containment hull

    Energy Technology Data Exchange (ETDEWEB)

    Samec, K

    2006-07-15

    The Full Scale Leak Test (FSLT) experiment is designed to replicate an accidental leak of Lead-Bismuth Eutectic (LBE) liquid metal from the MEGAPIE neutron spallation source. The neutron source is totally encased in an aluminum containment hull cooled by heavy water. Any liquid metal which would, in a hypothetical accident, leak into the helium-filled insulation gap between the source and the aluminum containment hull, would immediately impact the hull. Furthermore, during irradiation in the PSI SINQ facility, the LBE in the MEGAPIE Lower Liquid Metal Container (LLMC) accumulates radio-active substances which, in the event of a leak, must be cooled and contained under controlled conditions, as they may otherwise contaminate the facility. The FSLT experiment has been devised to fully test the structural integrity of the containment hull against a sudden liquid metal leak, and in addition, to resolve the peak temperature of he coolant, to validate the sensors used in detecting a leak and of proof-test the analytical methods used in predicting the consequences of a leak. The FSLT experiment has been analysed ahead of the test, and both thermal and structural aspects calculated using commercial codes. The predictions applied conservative assumptions to the analysis of the thermal shock so as to preclude the likelihood of an unforeseen failure of the hull. In this document, these initial predictions are compared to the temperature and strain data recorded in the experiment. Further analysis, to be published at a later stage, will focus on applying actual conditions realised in the experiment, as opposed to the envelope case used in the test predictions. The integrity of the containment hull under loads resulting from liquid metal-leak is therefore the focal point of the experiment described in the current document, and serves as a key reference test for the Iicensing of the facility. The data recorded during the SLT experiment shows that the MEGAPIE containment hull is

  8. Full scale leak test of the MEGAPIE containment hull

    International Nuclear Information System (INIS)

    Samec, K.

    2006-07-01

    The Full Scale Leak Test (FSLT) experiment is designed to replicate an accidental leak of Lead-Bismuth Eutectic (LBE) liquid metal from the MEGAPIE neutron spallation source. The neutron source is totally encased in an aluminum containment hull cooled by heavy water. Any liquid metal which would, in a hypothetical accident, leak into the helium-filled insulation gap between the source and the aluminum containment hull, would immediately impact the hull. Furthermore, during irradiation in the PSI SINQ facility, the LBE in the MEGAPIE Lower Liquid Metal Container (LLMC) accumulates radio-active substances which, in the event of a leak, must be cooled and contained under controlled conditions, as they may otherwise contaminate the facility. The FSLT experiment has been devised to fully test the structural integrity of the containment hull against a sudden liquid metal leak, and in addition, to resolve the peak temperature of he coolant, to validate the sensors used in detecting a leak and of proof-test the analytical methods used in predicting the consequences of a leak. The FSLT experiment has been analysed ahead of the test, and both thermal and structural aspects calculated using commercial codes. The predictions applied conservative assumptions to the analysis of the thermal shock so as to preclude the likelihood of an unforeseen failure of the hull. In this document, these initial predictions are compared to the temperature and strain data recorded in the experiment. Further analysis, to be published at a later stage, will focus on applying actual conditions realised in the experiment, as opposed to the envelope case used in the test predictions. The integrity of the containment hull under loads resulting from liquid metal-leak is therefore the focal point of the experiment described in the current document, and serves as a key reference test for the Iicensing of the facility. The data recorded during the SLT experiment shows that the MEGAPIE containment hull is

  9. Proton decay: spectroscopic probe beyond the proton drip line

    International Nuclear Information System (INIS)

    Seweryniak, D; Davids, C N; Robinson, A; Woods, P J; Blank, B; Carpenter, M P; Davinson, T; Freeman, S J; Hammond, N; Hoteling, N; Janssens, R V F; Khoo, T L; Liu, Z; Mukherjee, G; Shergur, J; Sinha, S; Sonzogni, A A; Walters, W B; Woehr, A

    2005-01-01

    Proton decay has been transformed in recent years from an exotic phenomenon into a powerful spectroscopic tool. The frontiers of experimental and theoretical proton-decay studies will be reviewed. Different aspects of proton decay will be illustrated with recent results on the deformed proton emitter 135 Tb, the odd-odd deformed proton emitter 130 Eu, the complex fine structure in the odd-odd 146 Tm nucleus and on excited states in the transitional proton emitter 145 Tm

  10. NOEL: a no-leak fusion blanket concept

    International Nuclear Information System (INIS)

    Powell, J.R.; Yu, W.S.; Fillo, J.A.; Horn, F.L.; Makowitz, H.

    1980-01-01

    Analysis and tests of a no-leak fusion blanket concept (NOEL-NO External Leak) are described. Coolant cannot leak into the plasma chamber even if large through-cracks develop in the first wall. Blanket modules contain a two-phase material, A, that is solid (several cm thick) on the inside of the module shell, and liquid in the interior. The solid layer is maintained by imbedded tubes carrying a coolant, B, below the freezing point of A. Most of the 14-MeV neutron energy is deposited as heat in the module interior. The thermal energy flow from the module interior to the shell keeps the interior liquid. Pressure on the liquid A interior is greater than the pressure on B, so that B cannot leak out if failures occur in coolant tubes. Liquid A cannot leak into the plasma chamber through first wall cracks because of the intervening frozen layer. The thermal hydraulics and neutronics of NOEL blankets have been investigated for various metallic (e.g., Li, Pb 2 , LiPb, Pb) and fused salt choices for material A

  11. Maintaining leak tightness capability of Caorso BWR containment

    International Nuclear Information System (INIS)

    Barsanti, P.; Di Palo, L.; Grimaldi, G.

    1988-01-01

    In 1987 the local leak rate test (LLRT) results of the primary containment were revised, with the following main goals: to highlight recurring problems, leading to lack of leak tightness of the primary containment; to individuate the pertinent degradation mechanisms; to assess the corrective actions already implemented and to plan further improvements, if necessary; and to optimize the preventive maintenance program on the containment, particularly the inspection frequency. All LLRTs in the past operating period, both before (as found) and after (as left) maintenance were analyzed, in terms of leakage rate and equivalent area of leak, for each penetration. Corrective actions already implemented included replacement of some valves with better quality type one, passivation of the carbon steel pipes and improvement of the pertinent surveillance procedures. Long term corrective actions, now under consideration, will include the following: more extensive passivation of pipes, carrying humid air, so that oxidation could be drastically reduced; better chemistry control in fluid systems; extensive replacement of the butterfly valves presently used; implementation of the LLRT practice, such to quantitatively measure the leakage rate, also in presence of large leak; and reduction of the time interval between periodical tests, on the basis of the results of the previous ones. Following these guidelines, future overall leakage tests would be performed in as found condition, aimed to verify the effectiveness of the entire maintenance and testing program of the primary containment and of its capability to maintain leak tightness during the time between two subsequent tests

  12. Leak-before-break behaviour of nuclear piping systems

    International Nuclear Information System (INIS)

    Bartholome, G.; Wellein, R.

    1992-01-01

    The general concept for break preclusion of nuclear piping systems in the FRG consists of two main prerequisites: Basic safety; independent redundancies. The leak-before-break behaviour is open of these redundancies and will be verified by fracture mechanics. The following items have to be evaluated: The growth of detected and postulated defects must be negligible in one life time of the plant; the growth behaviour beyond design (i.e. multiple load collectives are taken into account) leads to a stable leak; This leakage of the piping must be detected by an adequate leak detection system long before the critical defect size is reached. The fracture mechanics calculations concerning growth and instability of the relevant defects and corresponding leakage areas are described in more detail. The leak-before-break behaviour is shown for two examples of nuclear piping systems in pressurized water reactors: main coolant line of SIEMENS-PWR 1300 MW (ferritic material, diameter 800 mm); surge line of Russian WWER 440 (austenitic material, diameter 250 mm). The main results are given taking into account the relevant leak detection possibilities. (author). 9 refs, 9 figs

  13. Helium Leak Test for the PLS Storage Ring Chamber

    International Nuclear Information System (INIS)

    Choi, M. H.; Kim, H. J.; Choi, W. C.

    1993-01-01

    The storage ring vacuum system for the Pohang Light Source (PLS) has been designed to maintain the vacuum pressure of 10 1 0 Torr which requires UHV welding to have helium leak rate less than 1x10 1 0 Torr·L/sec. In order to develop new technique (PLS) welding technique), a prototype vacuum chamber has been welded by using Tungsten Inert Gas welding method and all the welded joints have been tested with a non-destructive method, so called helium leak detection, to investigate the vacuum tightness of the weld joints. The test was performed with a detection limit of 1x10 1 0 Torr·L/sec for helium and no detectable leaks were found for all the welded joints. Thus the performance of welding technique is proven to meet the criteria of helium leak rate required in the PLS Storage Ring. Both the principle and the procedure for the helium leak detection are also discussed

  14. CEGB research on boiler leaks and their detection in service

    International Nuclear Information System (INIS)

    Hayes, D.J.

    1978-01-01

    The penalty in loss of output to an electricity generation organisation as a consequence of failure to deal effectively with small LMFBR boiler leaks would be large. There is therefore a considerable incentive for these organisations to satisfy themselves that proper provisions are made to ensure that both the incidence and the severity of boiler leaks are minimised. In the UK, responsibility for the research, development and design work for this and indeed for most aspects of future nuclear power plant rests with the UKAEA and NPC; nevertheless as a consequence of its 'informed operator' policy the Central Electricity Generating Board has devoted some research effort to this field in recent years. o date, research work has been put in hand with the objective of achieving an understanding of the basic behaviour of boiler leaks. In addition, attention has been given to leak detection by monitoring the sodium for increases in oxygen and hydrogen levels. In both cases leaks into liquid sodium rather than into the gas space have been considered. In the course of the work hydrogen and oxygen meters based on the galvanic cell principle have been constructed and evaluated. The former is a new device which is comparable in performance with hydrogen meters based on the ion pump. The present state of the work is briefly described in this paper

  15. Operational experiences with on line BWR condenser tube leak verification

    International Nuclear Information System (INIS)

    Bryant, R.A.; Duvall, W.E.; Kirkley, W.B.; Zavadoski, R.W.

    1988-01-01

    Verifying condenser tube leaks at a boiling water reactor is, at best, a difficult task carried out in hot steamy water boxes with concurrent radiation exposure. For small apparent leaks with slight chemical changes there is always uncertainty of whether the problem is a condenser tube leak or a feedback from radwaste. Most conventional methods (e.g soap tests, Saran wrap suction, and helium tests) usually involve a load reduction to isolate the water boxes one at a time and hours of drain down on each box. The sensitivity of the most sensitive test (helium) is of the order of 7500 l per day per box. Sulfur hexafluoride has been successfully used at a BWR to identify one leaking water box out of four while the unit was at 100 % power. The actual tubes leakig in the water box were identified by injecting helium during drain down of the box and subsequent manifold testing. Additional tests with sulfur hexafluoride on the second BWR unit indicated tight water boxes to within the sensitivity of the measurement, i.e. less than 19 l per day for all four boxes. Problems encountered in both tests included sulfur hexafluoride carry over from the plume of the cooling towers and off gas considerations. In brief sulfur hexafluoride can be used to quickly identify which particular water box has a condenser tube leak or, just as quickly, establish the integrity of all the water boxes to a level not previously attainable. (author)

  16. CEGB research on boiler leaks and their detection in service

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, D J [Berkeley Nuclear Laboratories, Berkeley, Gloucestershire (United Kingdom)

    1978-10-01

    The penalty in loss of output to an electricity generation organisation as a consequence of failure to deal effectively with small LMFBR boiler leaks would be large. There is therefore a considerable incentive for these organisations to satisfy themselves that proper provisions are made to ensure that both the incidence and the severity of boiler leaks are minimised. In the UK, responsibility for the research, development and design work for this and indeed for most aspects of future nuclear power plant rests with the UKAEA and NPC; nevertheless as a consequence of its 'informed operator' policy the Central Electricity Generating Board has devoted some research effort to this field in recent years. o date, research work has been put in hand with the objective of achieving an understanding of the basic behaviour of boiler leaks. In addition, attention has been given to leak detection by monitoring the sodium for increases in oxygen and hydrogen levels. In both cases leaks into liquid sodium rather than into the gas space have been considered. In the course of the work hydrogen and oxygen meters based on the galvanic cell principle have been constructed and evaluated. The former is a new device which is comparable in performance with hydrogen meters based on the ion pump. The present state of the work is briefly described in this paper.

  17. Review of inelastic proton-proton reactions

    CERN Document Server

    Morrison, Douglas Robert Ogston

    1973-01-01

    The most important new results on inelastic proton-proton scattering obtained with the new machines, I.S.R. and N.A.L., are: (1) The inelastic cross-section increases monotonically with energy from threshold to 1500 GeV/c. Above 6 GeV/c the energy variation has a s /sup +0.04/ behaviour. (2) Scaling is observed at I.S.R. energies in pion production. Confirmation is obtained of the hypothesis of limiting fragmentation. (3) The results are in general, consistent with the two-component model-one class of events being produced by diffraction dissociation and the other by a short-range-order process (e.g. the multiperipheral model). (4) There are indications that the protons have a granular structure; this from observation of secondaries of large transverse momenta. (33 refs).

  18. Proton ejection project for Saturne

    International Nuclear Information System (INIS)

    Bronca, G.; Gendreau, G.

    1959-01-01

    The reasons for choosing the ejection system are given. The characteristics required for the ejected beam are followed by a description of the ejection process, in chronological order from the viewpoint of the protons: movement of the particles, taking into account the various elements which make up the system (internal magnet, external magnet, quadrupoles, ejection correction coils, thin and thick cables,...) and specification of these elements. Then follows an estimation of the delay in manufacture and the cost of the project. Finally, the characteristics of the magnets and quadrupoles are listed in an appendix. (author) [fr

  19. Acoustic valve leak detection in nuclear plants

    International Nuclear Information System (INIS)

    Dimmick, J.G.; Dickey, J.W.

    1983-01-01

    Internal valve leakage is a hidden energy loss and can cause or prolong a forced outage. Recent advances in acoustic detection of internal valve leakage have reduced piping system maintenance costs, unnecessary downtime, and energy waste. Extremely short payback periods have been reported by plants applying this technology to preventive maintenance, troubleshooting, energy conservation and outage planning. Sensors temporarily attached to the outside of valves and connected to the instruments detect ultrasonic acoustic emissions which are characteristic of internal valve leakage. Since the sensors are attached to the outside of the valves, the time and expense of dismantling the valves or removing them from the systems are eliminated. This paper describes the instrumentation and specific applications to nuclear plant valves, including independent verification of initial findings. Guidelines for potential users, including instrumentation selection, training requirements, application planning, and the choice of in-house versus contract services are discussed

  20. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Nissen, Poul

    2008-01-01

    molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...... proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK (a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires....