WorldWideScience

Sample records for thermal shock testing

  1. Evaluation of Defects of Thermal Barrier Coatings by Thermal Shock Test Using Eddy Current Testing

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Tae Hoon; Cho, Youn Ho; Lee, Joon Hyun [Pusan National University, Busan (Korea, Republic of); Oh, Jeong Seok; Lee, Koo Hyun [KIMM, Daejeon (Korea, Republic of)

    2009-10-15

    Periodical thermal shock can introduce defects in thermal barrier coating made by layers of CoNiCrAlY bond coating(BC) and ZrO{sub 2}-8wt%Y{sub 2}O{sub 3} ceramic top coating(TC) on Inconel-738 substrate using plasma spraying. Thermal shock test is performed by severe condition that is to heat until 1000 .deg. C and cool until 20 .deg. C. As the number of cycle is increased, the fatigue by thermal shock is also increased. After test, the micro-structures and mechanical characteristics of thermal barrier coating were investigated by SEM, XRD. The TGO layer of is Al{sub 2}O{sub 3} formed between BC and TC by periodical thermal shock test, and its change in thickness is inspected by eddy current test(ECT). By ECT test, it is shown that TGO and micro-crack can be detected and it is possible to predict the life of thermal barrier coating

  2. Thermal shock test of TiC and graphite

    International Nuclear Information System (INIS)

    Shirakawa, H.; Okamura, J.; Son, P.; Miyake, M.

    1989-01-01

    Thermal shock tests were performed by pulse electron beam heating on chemically vapor deposited coatings of TiC on Poco graphite, bulk TiC, and several kinds of isotropic graphite. The specimens were heated at various power densities (10-45 MW/m 2 ) for various pulse durations (1-2 s) to examine the dependence of thermal failures on heating conditions. The TiC coating on graphite suffered cracking, surface melting and evaporation by the thermal pulse. The surface melting limit, defined as F τ 1/2 , where F is the minimum power density that causes surface melting for a specified pulse duration τ, was approximately 48 MWs 1/2 /m 2 for the TiC coating. The combined-Carbon/Titanium ratio of the coating after electron beam heating decreased with increasing power density and pulse duration. The bulk TiC specimens were so brittle that they fractured at heat load conditions where the coating showed no damage. The graphite specimens showed sublimation as a principal damage mechanism by the thermal pulse, and the sublimation weight loss decreased with increasing the thermal conductivity of the specimen. It was confirmed that the TiC coating on graphite had favorable resistance to thermal shock as compared to the bulk TiC and that graphite with high thermal conductivity is promising material as a high heat flux component. (orig.)

  3. Thermal shock testing of ceramics with pulsed laser irradiation

    International Nuclear Information System (INIS)

    Benz, R.; Naoumidis, A.; Nickel, H.

    1986-04-01

    Arguments are presented showing that the resistance to thermal stressing (''thermal shock'') under pulsed thermal energy deposition by various kinds of beam irradiations is approximately proportional to Φ a √tp, where Φ a is the absorbed power density and tp is the pulse length, under conditions of diffusivity controlled spreading of heat. In practical beam irradiation testing, incident power density, Φ, is reported. To evaluate the usefulness of Φ√tp as an approximation to Φ a √tp, damage threshold values are reviewed for different kinds of beams (electron, proton, and laser) for a range of tp values 5x10 -6 to 2 s. Ruby laser beam irradiation tests were made on the following ceramics: AlN, BN, graphite, αSiC, β-SiC coated graphites, (α+β)Si 3 N 4 , CVD (chemical vapor deposition) TiC coated graphite, CVD TiC coated Mo, and CVD TiN coated IN 625. The identified failure mechanisms are: 1. plastic flow followed by tensile and bend fracturing, 2. chemical decomposition, 3. melting, and 4. loss by thermal spallation. In view of the theoretical approximations and the neglect of reflection losses there is reasonable accord between the damage threshold Φ√tp values from the laser, electron, and proton beam tests. (orig./IHOE)

  4. Thermal shock testing of TiC-coated molybdenum with pulsed hydrogen beams

    International Nuclear Information System (INIS)

    Nakamura, Kazuyuki

    1985-07-01

    Thermal shock testing of molybdenum samples, on which TiC is coated by TP-CVD and CVD methods, has been made by using a pulsed hydrogen beam. The power density applied was 2 kw/cm 2 . The test results showed that TiC coatings did not exfoliate until the melting of the substrate and showed good adhesion under the thermal shock condition. (author)

  5. High pulse number thermal shock tests on tungsten with steady state particle background

    Science.gov (United States)

    Wirtz, M.; Kreter, A.; Linke, J.; Loewenhoff, Th; Pintsuk, G.; Sergienko, G.; Steudel, I.; Unterberg, B.; Wessel, E.

    2017-12-01

    Thermal fatigue of metallic materials, which will be exposed to severe environmental conditions e.g. plasma facing materials in future fusion reactors, is an important issue in order to predict the life time of complete wall components. Therefore experiments in the linear plasma device PSI-2 were performed to investigate the synergistic effects of high pulse number thermal shock events (L = 0.38 GW m-2, Δt = 0.5 ms) and stationary D/He (6%) plasma particle background on the thermal fatigue behavior of tungsten. Similar to experiments with pure thermal loads, the induced microstructural and surface modifications such as recrystallization and roughening as well as crack formation become more pronounced with increasing number of thermal shock events. However, the amount of damage significantly increases for synergistic loads showing severe surface roughening, plastic deformation and erosion resulting from the degradation of the mechanical properties caused by bombardment and diffusion of D/He to the surface and the bulk of the material. Additionally, D/He induced blistering and bubble formation were observed for all tested samples, which could change the thermal and mechanical properties of near surface regions.

  6. Thermal shock testing of low-Z coatings with pulsed hydrogen beams

    International Nuclear Information System (INIS)

    Nakamura, Kazuyuki

    1982-03-01

    Thermal shock testing of candidate low-Z surface coatings for JT-60 application has been made by using a pulsed hydrogen beam apparatus which is operated at a power density of 2KW/cm 2 . The materials tested are PVD (Physical Vapor Deposited) TiC and PVD and CVD (Chemical Vapor Deposited) TiN on molybdenum and Inconel 625. The result shows that CVD TiC on Mo and CVD TiN on Inconel are the most interesting choices for the coating-substrate combinations. (author)

  7. Thermal shock tests to qualify different tungsten grades as plasma facing material

    Science.gov (United States)

    Wirtz, M.; Linke, J.; Loewenhoff, Th; Pintsuk, G.; Uytdenhouwen, I.

    2016-02-01

    The electron beam device JUDITH 1 was used to establish a testing procedure for the qualification of tungsten as plasma facing material. Absorbed power densities of 0.19 and 0.38 GW m-2 for an edge localized mode-like pulse duration of 1 ms were chosen. Furthermore, base temperatures of room temperature, 400 °C and 1000 °C allow investigating the thermal shock performance in the brittle, ductile and high temperature regime. Finally, applying 100 pulses under all mentioned conditions helps qualifying the general damage behaviour while with 1000 pulses for the higher power density the influence of thermal fatigue is addressed. The investigated reference material is a tungsten product produced according to the ITER material specifications. The obtained results provide a general overview of the damage behaviour with quantified damage characteristics and thresholds. In particular, it is shown that the damage strongly depends on the microstructure and related thermo-mechanical properties.

  8. Experimental facilities for PEC reactor design central channel test loop: CPC-1 - thermal shocks loop: CEDI

    International Nuclear Information System (INIS)

    Calvaresi, C.; Moreschi, L.F.

    1983-01-01

    PEC (Prova Elementi di Combustibile: Fuel Elements Test) is an experimental fast sodium-cooled reactor with a power of 120 MWt. This reactor aims at studying the behaviour of fuel elements under thermal and neutron conditions comparable with those existing in fast power nuclear facilities. Given the particular structure of the core, the complex operations to be performed in the transfer cell and the strict operating conditions of the central channel, two experimental facilities, CPC-1 and CEDI, have been designed as a support to the construction of the reactor. CPC-1 is a 1:1 scale model of the channel, transfer-cell and loop unit of the channel, whereas CEDI is a sodium-cooled loop which enables to carry out tests of isothermal endurance and thermal shocks on the group of seven forced elements, by simulating the thermo-hydraulic and mechanical conditions existing in the reactor. In this paper some experimental test are briefy discussed and some facilities are listed, both for the CPC-1 and for the CEDI. (Auth.)

  9. Pressurized thermal shock (PTS)

    International Nuclear Information System (INIS)

    Rosso, Ricardo D.; Ventura, Mirta A.

    2006-01-01

    In the present work, a description of Thermal Shock in Pressurized conditions (PTS), and its influence in the treatment of the integrity of the pressure vessel (RPV) of a Pressurized Water Reactor (PWR) and/or of a Heavy water Pressurized water Reactor (PHWR) is made. Generally, the analysis of PTS involves a process of three stages: a-) Modeling with a System Code of relevant thermohydraulics transients in reference with the thermal shock; b-) The local distribution of temperatures in the downcomer and the heat transference coefficients from the RPV wall to the fluid, are determined; c-) The fracture mechanical analysis. These three stages are included in this work: Results with the thermohydraulics code Relap5/mod.3, are obtained, for a LOCA scenario in the hot leg of the cooling System of the Primary System of the CAN-I reactor. The method used in obtaining results is described. A study on the basis of lumped parameters of the local evolutions of the temperature of the flow is made, in the downcomer of the reactor pressure vessel. The purpose of this study is to determine how the intensification of the stress coefficient, varies in function of the emergency injected water during the thermohydraulic transients that take place under the imposed conditions in the postulated scene. Specially, it is considered a 50 cm 2 break, located in the neighborhoods of the pressurized with the corresponding hot leg connection. This size is considered like the most critical. The method used to obtain the results is described. The fracture mechanical analysis is made. From the obtained results we confirmed that we have a simple tool of easy application in order to analyze phenomena of the type PTS in the postulated scenes by break in the cold and hot legs of the primary system. This methodology of calculus is completely independent of the used ones by the Nucleoelectrica Argentina S.A. (NASA) in the analysis of the PTS phenomena in the CAN-I. The results obtained with the adopted

  10. Pressurized Thermal Shock, Pts

    International Nuclear Information System (INIS)

    Boyd, C.

    2008-01-01

    Pressurized Thermal Shock (Pts) refers to a condition that challenges the integrity of the reactor pressure vessel. The root cause of this problem is the radiation embrittlement of the reactor vessel. This embrittlement leads to an increase in the reference temperature for nil ductility transition (RTNDT). RTNDT can increase to the point where the reactor vessel material can loose fracture toughness during overcooling events. The analysis of the risk of having a Pts for a specific plant is a multi-disciplinary problem involving probabilistic risk analysis (PRA), thermal-hydraulic analysis, and ultimately a structural and fracture analysis of the vessel wall. The PRA effort involves the postulation of overcooling events and ultimately leads to an integrated risk analysis. The thermal-hydraulic effort involves the difficult task of predicting the system behavior during a postulated overcooling scenario with a special emphasis on predicting the thermal and mechanic loadings on the reactor pressure vessel wall. The structural and fracture analysis of the reactor vessel wall relies on the thermal-hydraulic conditions as boundary conditions. The US experience has indicated that medium and large diameter primary system breaks dominate the risk of Pts along with scenarios that involve a stuck open valve (and associated system cooldown) that recloses resulting in system re-pressurization while the vessel wall is cool.

  11. Temperatures, strains and crack behavior during local thermal shock tests on the RPV-cylinder of the HDR

    International Nuclear Information System (INIS)

    Neubrech, G.E.; Goerner, F.; Siebler, T.

    1987-01-01

    This report summarises and critically discusses the results obtained from thermal shocks locally applied to the inner surface of the RPV-cylinder. This evaluation is based on on-line measurements (temperatures and strains at the RPV-wall during the thermal shock loading, non-destructive-testing), on materials investigations, and on theoretical investigations (finite element calculations, fracture mechanics analyses). The comparison between the corresponding measured and calculated results serves as a basis for subsequent assessments. It was the object of these tests to achieve the following primary aims: - Investigation of the loading conditions produced by local thermal shocks during realistic cooling processes. - A better understanding of the physical processes involved in crack initiation and propagation resulting from thermocyclic loading. - Assessment of non-destructive-testing methods with respect to detection and analysis of cracks as a basis for fracture mechanical evaluations. - Assessment of the reliability of the applied structural analysis methods. - Production of naturally formed deep cracks on the inner surface of the RPV-cylinder by means of excessive cooling processes. (orig./HP)

  12. Thermal shock cracking of GSO single crystal

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Yamamoto, Kazunari; Tamura, Takaharu; Kurashige, Kazuhisa; Ishibashi, Hiroyuki; Susa, Kenzo

    1998-01-01

    The quantitative estimation of the failure stress of a gadolinium orthosilicate (Gd 2 SiO 5 , hereafter abbreviated as GSO) single crystal due to thermal shock was investigated. A cylindrical test specimen was heated in a silicone oil bath, then subjected to thermal shock by pouring room temperature silicone oil. Cracking occurred during cooling. The heat conduction analysis was performed to obtain temperature distribution in a GSO single crystal at cracking, using the surface temperatures measured in the thermal shock cracking test. Then the thermal stress was calculated using temperature profile of the test specimen obtained from the heat conduction analysis. It is found from the results of the thermal stress analysis and the observation of the cracking in test specimens that the thermal shock cracking occurs in a cleavage plane due to the stress normal to the plane. Three-point bending tests were also performed to examine the relationship between the critical stress for thermal shock cracking and the three-point bending strength obtained from small-sized test specimens. (author)

  13. A new method for testing thermal shock resistance properties of soapstone – Effects of microstructures and mineralogical variables

    Directory of Open Access Journals (Sweden)

    A. Huhta

    2016-09-01

    Full Text Available Soapstone industry utilizes different types of soapstone mainly as a construction material for fireplaces. In this application soapstone has to meet different temperature requirements in different parts of fireplaces. Mineralogical and structural information is needed for placing an appropriate type of soapstone in an appropriate position in the fireplace construction. This allows employment of higher temperatures resulting in more particulate-free combustion, which makes it possible for soapstone industry to develop more efficient and environmentally friendly fireplaces. Of many soapstone types, which differ from each other in their chemical composition and thermal properties, carbonate soapstone and its microstructural variations were investigated in this study. A new method was developed to measure thermal shock resistant of natural stones. By exposing carbonate soapstone samples of different textural types to rapid temperature changes, it was possible to determine the parameters that affect the capacity of the rock to resist thermal shock. The results indicate that the type of microtexture is an important factor in controlling the thermal shock resistance of carbonate soapstone. The soapstone samples with a high thermal shock resistance show deformation textures, such as crenulation cleavage and S/C mylonite. A strong negative correlation was observed between the thermal shock resistance and length of cleavage domains in foliated rocks. Also a slight elevation in the iron concentration of talc and magnesite was discovered to improve the thermal shock resistance of carbonate soapstone. Attention should especially be paid to the length and planarity of cleavage domains of spaced foliation.

  14. Pressurized thermal shocks: the JRC Ispra experimental test rig and analytical results

    International Nuclear Information System (INIS)

    Jovanovic, A.; Lucia, A.C.

    1990-01-01

    The paper tackles some issues of particular interest for the remanent (remaining) life prediction for the pressurized components exposed to pressurized thermal shock (PTS) loads, that have been tackled in analytical work performed in the framework of the MPA - JRC collaboration for the PTS experimental research at the JRC Ispra. These issues regard in general application of damage mechanics, fracture mechanics and artificial intelligence (including the treatment of uncertainties in the PTS analysis and experiments). The considered issues are essential for further understanding and modelling of the crack behaviour and of the component response in PTS conditions. In particular, the development of the FRAP preprocessor and development and implementation of a methodology for analysis of local non-stationary heat transfer coefficients during a PTS, have been explained more in detail. FRAP is used as a frontend, for the finite element code ABAQUS, for the heat transfer, stress and fracture mechanics analyses. The ABAQUS results are used further on, for the probabilistic fatigue crack growth analysis performed by the COVASTOL code. (author)

  15. Pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    Whitman, G.D.; McCulloch, R.W.

    1982-01-01

    The primary objective of the ORNL pressurized-thermal-shock (PTS) experiments is to verify analytical methods that are used to predict the behavior of pressurized-water-reactor vessels under these accident conditions involving combined pressure and thermal loading. The criteria on which the experiments are based are: scale large enough to attain effective flaw border triaxial restraint and a temperature range sufficiently broad to produce a progression from frangible to ductile behavior through the wall at a given time; use of materials that can be completely characterized for analysis; stress states comparable to the actual vessel in zones of potential flaw extension; range of behavior to include cleavage initiation and arrest, cleavage initiation and arrest on the upper shelf, arrest in a high K/sub I/ gradient, warm prestressing, and entirely ductile behavior; long and short flaws with and without stainless steel cladding; and control of loads to prevent vessel burst, except as desired. A PTS test facility is under construction which will enable the establishment and control of wall temperature, cooling rate, and pressure on an intermediate test vessel (ITV) in order to simulate stress states representative of an actual reactor pressure vessel

  16. Thermal shock considerations for the TFCX limiter and first wall

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Resistance to thermal shock fracture of limiter and first wall surface material candidates during plasma disruption heating conditions is evaluated. A simple, figure-of-merit type thermal shock parameter which provides a mechanism to rank material candidates is derived. Combining this figure-of-merit parameter with the parameters defining specific heating conditions yields a non-dimensional thermal shock parameter. For values of this parameter below a critical value, a given material is expected to undergo thermal shock damage. Prediction of thermal shock damage with this parameter is shown to exhibit good agreement with test data. Applying this critical parameter value approach, all materials examined in this study are expected to experience thermal shock damage for nominal TFCX plasma disruption conditions. Since the extent of this damage is not clear, tests which explore the range of expected conditions for TFCX are recommended

  17. Shock resistance testing

    International Nuclear Information System (INIS)

    Pouard, M.

    1984-03-01

    In the framework of mechanical tests and to answer the different requests for tests, the T.C.R (Transport Conditionnement et Retraitement) laboratory got test facilities. These installations allow to carry out tests of resistance to shocks, mainly at the safety level of components of nuclear power plants, mockups of transport casks for fuel elements and transport containers for radioactive materials. They include a tower and a catapult. This paper give a decription of the facilities and explain their operation way [fr

  18. Thermal shock behaviour of SiC-fibre-reinforced glasses

    International Nuclear Information System (INIS)

    Klug, T.; Reichert, J.; Brueckner, R.

    1992-01-01

    The preparation of two SiC-fibre-reinforced glasses with very different thermal expansion coefficients and glass transition temperatures is described and the influence of long-time temperature and thermal shock behaviour of these composites on the mechanical properties is investigated by means of bending test experiments before and after thermal treatments. It will be shown from experiments and calculations on stresses due to thermal expansion mismatch between fibre and glass matrix that not only best mechanical properties but also best thermal shock behaviour are connected with low tensile intrinsic stresses produced by thermal expansion mismatch during preparation. The thermal shock resistance of the best composite (SiC fibre/DURAN glass) does not show a significant decrease of flexural strength even after 60 shocks from 550 to 25deg C in water, while the bulk glass sample of the same dimension was destroyed by one thermal shock from 350deg C. (orig.) [de

  19. Pressurized-thermal-shock technology

    International Nuclear Information System (INIS)

    Dickson, T.L.

    1991-01-01

    It was recognized at the time the original Issues on Pressurized Thermal Shock (IPTS) studies were conducted that distinct vertical plumes of cooling water form beneath the cold leg inlet nozzles during those particular transients that exhibit fluid/thermal stratification. The formation of these plumes (referred to as thermal streaming) induces a time-dependent circumferential temperature variation on the inner surface of the Reactor Pressure Vessel (RPV) wall that creates an axial stress component. This axial stress component is in addition to the axial stress components induced by time-dependent radial temperature variation through the wall thickness and the time-dependent pressure transient. This additional axial stress component will result in a larger axial stress resultant that results in a larger stress-intensity factor acting on circumferential flaws, thus reducing the fracture margin for circumferential flaws. Although this was recognized at the time of the original IPTS study, the contribution appeared to be relatively small; therefore, it was neglected. The original IPTS studies were performed with OCA-P, a computer program developed at ORNL to analyze the cleavage fracture response of a nuclear RPV subjected to PTS loading. OCA-P is a one-dimensional (1-D) finite-element code that analyzes the stresses and stress-intensity factors (axial and tangential) resulting from the pressure and the radial temperature variation through the wall thickness only. The HSST Program is investigating the potential effects of thermal-streaming-induced stresses in circumferential welds on the reactor vessel PTS analyses. The initial phase of this investigation focused on an evaluation of the available thermal-hydraulic data and analyses results. The objective for the initial phase of the investigation is to evaluate thermal-streaming behavior under conditions relevant to the operation of U.S. PWRs and chracterize any predicted thermal-streaming plumes

  20. Thermal shock tests with beryllium coupons in the electron beam facility JUDITH

    International Nuclear Information System (INIS)

    Roedig, M.; Duwe, R.; Schuster, J.L.A.

    1995-01-01

    Several grades of American and Russian beryllium have been tested in high heat flux tests by means of an electron beam facility. For safety reasons, major modifications of the facility had to be fulfilled in advance to the tests. The influence of energy densities has been investigated in the range between 1 and 7 MJ/m 2 . In addition the influence of an increasing number of shots at constant energy density has been studied. For all samples, surface profiles have been measured before and after the experiments. Additional information has been gained from scanning electron microscopy, and from metallography

  1. Dynamic Pressure of Liquid Mercury Target During 800-MeV Proton Thermal Shock Tests

    International Nuclear Information System (INIS)

    Allison, S.W.; Andriulli, J.B.; Cates, M.R.; Earl, D.D.; Haines, J.R.; Morrissey, F.X.; Tsai, C.C.; Wender, S.

    2000-01-01

    Described here are efforts to diagnose transient pressures generated by a short-pulse (about 0.5 microseconds) high intensity proton (∼ 2 * 10 14 per pulse) beam. Proton energy is 800-MeV. The tests were performed at the Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE-WNR). Such capability is required for understanding target interaction for the Spallation Neutron Source project as described previously at this conference.1-4 The main approach to effect the pressure measurements utilized the deflection of a diaphragm in intimate contact with the mercury. There are a wide variety of diaphragm-deflection methods used in scientific and industrial applications. Many deflection-sensing approaches are typically used, including, for instance, capacitive and optical fiber techniques. It was found, however, that conventional pressure measurement using commercial pressure gages with electrical leads was not possible due to the intense nuclear radiation environment. Earlier work with a fiber optic strain gauge demonstrated the viability of using fiber optics for this environment

  2. Elastic-plastic fracture mechanics study of thermal shock cracking

    International Nuclear Information System (INIS)

    Hirano, K.; Kobayashi, H.; Nakazawa, H.

    1980-01-01

    This paper describes thermal shock experiments conducted on a nuclear pressure vessel steel (A533 Grade B Class 1), an AISI304 steel and a tool steel (JIS SKD62) using both a new thermal shock test facility and method. Analysis of their quasi-static thermal stress intensity factors is performed on the basis of linear-elastic fracture mechanics; and a thermal shock fracture toughness value, Ksub(tsc) is evaluated. Then elastic-plastic fracture toughness tests are carried out in the same high temperature range of the thermal shock experiment, and a relation between the stretched zone width, SZW, formed as a result of the fatigue precrack tip plastic blunting and the J-integral is clarified. An elastic-plastic thermal shock fracture toughness value, Jsub(tsc), is evaluated from a critical value of the stretched zone width, SZWsub(tsc), at the initiation of the thermal shock cracking by using the relation between SZW and J. The Jsub(tsc) value is compared with an elastic-plastic fracture toughness value, Jsub(Ic), and the difference between these Jsub(tsc) and Jsub(Ic) values is discussed on the basis of fractography. (author)

  3. Strain measurements during pressurized thermal shock experiment

    International Nuclear Information System (INIS)

    Tarso Vida Gomes, P. de; Julio Ricardo Barreto Cruz; Tanius Rodrigues Mansur; Denis Henrique Bianchi Scaldaferri; Miguel Mattar Neto

    2005-01-01

    For the life extension of nuclear power plants, the residual life of most of their components must be evaluated along all their operating time. Concerning the reactor pressure vessel, the pressurized thermal shock (PTS) is a very important event to be considered. For better understanding the effects of this kind of event, tests are made. The approach described here consisted of building a simplified in-scale physical model of the reactor pressure vessel, submitting it to the actual operating temperature and pressure conditions and provoking a thermal shock by means of cold water flow in its external surface. To conduct such test, the Nuclear Technology Development Center (CDTN) has been conducting several studies related to PTS and has also built a laboratory that has made possible the simulation of the PTS loading conditions. Several cracks were produced in the external surface of the reactor pressure vessel model. Strain gages were fixed by means of electrical discharge welding over the cracks regions in both external and internal surfaces. The temperature was monitored in 10 points across the vessel wall. The internal pressure was manually controlled and monitored using a pressure transducer. Two PTS experiments were conducted and this paper presents the strain measurement procedures applied to the reactor pressure vessel model, during the PTS, using strain gages experimental methodology. (authors)

  4. Thermal shock investigation of silicon nitride

    International Nuclear Information System (INIS)

    Ziegler, G.; Leucht, R.

    1977-01-01

    In this work, the thermal shock properties of commercial reaction-bonded Si 3 N 4 quality material (RBSN), of commercial hot-pressed Si 3 N 4 (HPSN) and of different laboratory grades of hot-pressed Si 3 N 4 were examined. The thermal shock properties of RBSN quality material differ according to the structure considerably: The critical temperature difference for sample crossections of 5 x 5 or 6 x 6 mm after quenching in oil lies between 730 0 C and over 1400 0 C. The best thermal shock properties are shown by high density RBSN quality material having very fine pores and high initial strength. The results indicate that for RBSN large pores and density inhomogenities are responsible for bad thermal shock properties. Resistance to fast temperature change is higher for hot-pressed Si 3 N 4 than for RBSN quality material. In HPSN, the thermal shock results show dependence on structure. High MgO content and the associated coarse rod-shaped configuration of the β phase and structural inhomogenities affect the thermal shock properties in an adverse way. (orig.) [de

  5. Thermal shock problems in a plate

    International Nuclear Information System (INIS)

    Takeuti, Y.; Furukawa, T.

    1981-01-01

    The problems considered are coupled dynamic thermoelastic analysis in a plate. First we try to examine a problem of the coupled dynamic thermal stress problem with small time approximation for the finite region. Next, we treatise both effects individually by pursuing rigorous anaylsis without small time approximation. Finally we consider thermal shock problems in a plate against different values of heat transfer coefficient (Biot's number) for the time. In conclusion, for usual materials, the inertia effect may be disregarded in the pure thermal problems in contrast to the coupling effect which brings small lags in the temperature and thermal stress distributions. For the consideration of the maximum thermal stress problems, Manson's uncoupled quasi-static results give enough approximation to the thermal shock problems without significant error from our numerical results. The analysis is developed by the use of Laplace transforms and several useful graphical illustrations are given. (orig./HP)

  6. Thermal shock resistances of a bonding material of C/C composite and copper

    International Nuclear Information System (INIS)

    Kurumada, Akira; Oku, Tatsuo; Kawamata, Kiyohiro; Motojima, Osamu; Noda, Nobuaki; McEnaney, B.

    1997-01-01

    The purpose of this study is to contribute to the development and the safety design of plasma facing components for fusion reactor devices. We evaluated the thermal shock resistance and the thermal shock fracture toughness of a bonding material which was jointed a carbon-fiber-reinforced carbon composite (C/C composite) to oxygen-free copper. We also examined the microstructures of the bonding layers using a scanning electron microscope before and after thermal shock tests. The bonding material did not fracture during thermal shock tests. However, thermal cracks and delamination cracks were observed in the bonding layers. (author)

  7. Thermal Shielding Effects of a Damaged Shock Absorber and an Intact Shock Absorber

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K. S.; Lee, J. C.; Kim, K. Y.; Seo, C. S.; Seo, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    In order to safely transport the radioactive waste arising from the hot test of an ACP(Advanced Spent Fuel Conditioning Process) a shipping package is required. Therefore, KAERI is developing a shipping package to transport the radioactive waste arising from the ACPF during a hot test. The regulatory requirements for a Type B package are specified in the Korea Most Act 2009-37, IAEA Safety Standard Series No. TS-R-1, and US 10 CFR Part. These regulatory guidelines classify the hot cell cask as a Type B package, and state that the Type B package for transporting radioactive materials should be able to withstand a test sequence consisting of a 9 m drop onto an unyielding surface, a 1 m drop onto a puncture bar, and a 30 minute fully engulfing fire. Greiner et al. investigated the thermal protection provided by shock absorbers by using the CAFE computer code. To evaluate the thermal shielding effect of the shock absorber, the thermal test was performed by using a 1/2 scale model with a shock absorber which was damaged by both a 9 m drop test and a 1 m puncture test. For the purpose of comparison, the thermal test was also carried out by using a 1/2 scale model with the intact shock absorber

  8. Shock Isolation Elements Testing for High Input Loadings. Volume II. Foam Shock Isolation Elements.

    Science.gov (United States)

    SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*EXPANDED PLASTICS, (*SHOCK(MECHANICS), REDUCTION), TEST METHODS, SHOCK WAVES, STRAIN(MECHANICS), LOADS(FORCES), MATHEMATICAL MODELS, NUCLEAR EXPLOSIONS, HARDENING.

  9. Results of molten salt panel and component experiments for solar central receivers: Cold fill, freeze/thaw, thermal cycling and shock, and instrumentation tests

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, J.E.; Ralph, M.E.; Chavez, J.M.; Dunkin, S.R.; Rush, E.E.; Ghanbari, C.M.; Matthews, M.W.

    1995-01-01

    Experiments have been conducted with a molten salt loop at Sandia National Laboratories in Albuquerque, NM to resolve issues associated with the operation of the 10MW{sub e} Solar Two Central Receiver Power Plant located near Barstow, CA. The salt loop contained two receiver panels, components such as flanges and a check valve, vortex shedding and ultrasonic flow meters, and an impedance pressure transducer. Tests were conducted on procedures for filling and thawing a panel, and assessing components and instrumentation in a molten salt environment. Four categories of experiments were conducted: (1) cold filling procedures, (2) freeze/thaw procedures, (3) component tests, and (4) instrumentation tests. Cold-panel and -piping fill experiments are described, in which the panels and piping were preheated to temperatures below the salt freezing point prior to initiating flow, to determine the feasibility of cold filling the receiver and piping. The transient thermal response was measured, and heat transfer coefficients and transient stresses were calculated from the data. Freeze/thaw experiments were conducted with the panels, in which the salt was intentionally allowed to freeze in the receiver tubes, then thawed with heliostat beams. Slow thermal cycling tests were conducted to measure both how well various designs of flanges (e.g., tapered flanges or clamp type flanges) hold a seal under thermal conditions typical of nightly shut down, and the practicality of using these flanges on high maintenance components. In addition, the flanges were thermally shocked to simulate cold starting the system. Instrumentation such as vortex shedding and ultrasonic flow meters were tested alongside each other, and compared with flow measurements from calibration tanks in the flow loop.

  10. Low upper-shelf toughness, high transition temperature test insert in HSST [Heavy Section Steel Technology] PTSE-2 [Pressurized Thermal Shock Experiment-2] vessel and wide plate test specimens: Final report

    International Nuclear Information System (INIS)

    Domian, H.A.

    1987-02-01

    A piece of A387, Grade 22 Class 2 (2-1/4 Cr - 1 Mo) steel plate specially heat treated to produce low upper-shelf (LUS) toughness and high transition temperature was installed in the side wall of Heavy Section Steel Technology (HHST) vessel V-8. This vessel is to be tested by the Oak Ridge National Laboratory (ORNL) in the Pressurized Thermal Shock Experiment-2 (PTSE-2) project of the HSST program. Comparable pieces of the plate were made into six wide plate specimens and other samples. These samples underwent tensile tests, Charpy tests, and J-integral tests. The results of these tests are given in this report

  11. Radiative shocks with electron thermal conduction

    International Nuclear Information System (INIS)

    Borkowski, Kazimierz.

    1988-01-01

    The authors studies the influence of electron thermal conduction on radiative shock structure for both one- and two-temperature plasmas. The dimensionless ratio of the conductive length to the cooling length determines whether or not conduction is important, and shock jump conditions with conduction are established for a collisionless shock front. He obtains approximate solutions with the assumptions that the ionization state of the gas is constant and the cooling rate is a function of temperature alone. In the absence of magnetic fields, these solutions indicate that conduction noticeably influences normal-abundance interstellar shocks with velocities 50-100 km s -1 and dramatically affects metal-dominated shocks over a wide range of shock velocities. Magnetic fields inhibit conduction, but the conductive energy flux and the corresponding decrease in the post-shock electron temperature may still be appreciable. He calculates detailed steady-state radiative shock models in gas composed entirely of oxygen, with the purpose of explaining observations of fast-moving knots in Cas A and other oxygen-rich supernova remnants (SNRs). The O III ion, whose forbidden emission usually dominates the observed spectra, is present over a wide range of shock velocities, from 100 to 170 kms -1 . All models with conduction have extensive warm photoionization zones, which provides better agreement with observed optical (O I) line strengths. However, the temperatures in these zones could be lowered by (Si II) 34.8 μm and (Ne II) 12.8 μm cooling if Si and Ne are present in appreciable abundance relative to O. Such low temperatures would be inconsistent with the observed (O I) emission in oxygen-rich SNRs

  12. Development of a thermal fatigue test method for thermal barrier coatings by laser excitation using a laser thermal shock facility; Entwicklung eines Pruefverfahrens zur laserinduzierten thermischen Ermuedung thermischer Schutzschichten mittels einer Laser-Thermoschockpruefeinrichtung

    Energy Technology Data Exchange (ETDEWEB)

    Nies, Daniel

    2012-07-13

    The finite nature of fossil fuel supply and the growing environmental awareness become increasingly stronger motivations for the development of efficient gas turbines and jet engines for power generation or as engines for land-, sea- and water-based vehicles. One concept developed for this purpose are thermal barrier coatings, where the thermal load of components is reduced by applying a ceramic coating onto the components. In this work the possibility to use a laser thermal shock facility for thermo-cyclic testing of thermal barrier coatings is examined. A focused laser beam is used for heating the sample and a homogeneous temperature distribution on the sample surface is achieved by the used trajectory and radial adjusted laser power. The required improvements of the existing testing facility are explained, including the development of a new sample holder and of the testing and evaluation routines for the experiments. For the assessment of the initiation and evolution of damages, acoustic emission and thermographic methods are used. The possibilities and limits of these methods are assessed during the experiments. The work also includes an extensive temperature dependent characterisation of the ceramic material used for the thermal barrier coating. In this part, the measurement of the Young's modulus by a dynamic method is to be highlighted, as this is a rarely used technique. The characterisations show the expected values, except for a lower porosity as expected by the manufacturer and no significant phase changes during isothermal heat treatments. To reach sample surface temperatures above 1000 C, it is necessary to increase the absorption by an additional coating of magnetite. The temperature distribution on the surface is measured by an infrared camera, which is calibrated for this purpose. With the incorporated active air cooling of the sample backside, the temperature gradient can be controlled, but still leaves room for improvements. Already without

  13. Optimizing thermal shock resistance of layered refractories

    Energy Technology Data Exchange (ETDEWEB)

    Hein, Jarno; Kuna, Meinhard [Institute of Mechanics and Fluid Dynamics, Technical University Bergakademie Freiberg, Lampadiusstrasse 4, 09599 Freiberg (Germany)

    2012-06-15

    Severe thermal shocks may cause critical thermal stresses and failure in refractories or ceramic materials. To increase the thermal shock resistance, layered material structures are suggested. In order to optimize properties of these alternative structures, thermo-mechanical simulations are required. In this study, a finite difference method (FDM) is used for solving the partial differential equation of heat conduction with spatially varying parameters. The optimization of the strip's thermal shock resistance is exemplarily done on a 10 layered strip subjected to constant temperature jump on the top surface. Each layer can be set with different porous Al{sub 2}O{sub 3} and MgO ceramics, whose material properties are theoretically determined. In this study, an improved optimization method is developed that consists of a combination and sequence of Monte Carlo simulations and evolution strategies to overcome certain disadvantages of both techniques. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Pressurized thermal shock program sponsored by EPRI

    International Nuclear Information System (INIS)

    Stahlkopf, K.E.

    1983-01-01

    The potential for long term neutron embrittlement of reactor vessels has been recognized for a number of years. Reactor vessel thermal shock is not a new concern, but with a growing number of plants approaching their mid-lives, it is a concern that must be understood and dealt with. Recent attention has focused on the performance of vessels during overcooling transients. This concern was designated as Unresolved Safety Issue A-49 by the Nuclear Regulatory Commission in December 1981. The USNRC staff has identified eight overcooling events of concern in U.S. PWRs. The concern is currently limited to Pressurized Water Reactors. The Electric Power Research Institute (EPRI) has supported research on reactor vessel integrity for a number of years and has supported an extensive effort on reactor vessel pressurized thermal shock (PTS) over the last three years. In addition, EPRI has developed a linked set of computer codes to simulate the pressurized thermal shock transients and assess the integrity of the nuclear reactor vessels for various overcooling transients. This paper focuses on the integrated analysis approach being used by EPRI in performing such analysis. (orig.)

  15. Experimental and numerical studies of various thermal sleeves subjected to severe cyclic thermal shocks

    International Nuclear Information System (INIS)

    Masson, J.C.; Moinereau, D.

    1990-01-01

    During the first operating years of nuclear power plants of different countries, damage was encountered on thermal sleeves used as nozzle protection. Following this discovery studies were initiated to determine the causes and to find solutions. At first a problem of vibration was found and easily solved by reducing gaps and reinforcing the welding of the sleeves. But preliminary tests with cyclic thermal shocks showed a risk of fatigue crack initiation and propagation both in the sleeve fixation and in the nozzle. Therefore a large research and development program was led principally by EDF laboratories of Les Renardieres, to demonstrate the absence of nocivity of thermal shocks during the plants life time [fr

  16. Shock Isolation Elements Testing for High Input Loadings. Volume III. Mechanical Shock Isolation Elements.

    Science.gov (United States)

    SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*SPRINGS, (*SHOCK(MECHANICS), REDUCTION), TORSION BARS, ELASTOMERS, DAMPING, EQUATIONS OF MOTION, MODEL TESTS, TEST METHODS, NUCLEAR EXPLOSIONS, HARDENING.

  17. Evaluation of thermal shock strengths for graphite materials using a laser irradiation method

    International Nuclear Information System (INIS)

    Kim, Jae Hoon; Lee, Young Shin; Kim, Duck Hoi; Park, No Seok; Suh, Jeong; Kim, Jeng O.; Il Moon, Soon

    2004-01-01

    Thermal shock is a physical phenomenon that occurs during the exposure to rapidly high temperature and pressure changes or during quenching of a material. The rocket nozzle throat is exposed to combustion gas of high temperature. Therefore, it is important to select suitable materials having the appropriate thermal shock resistance and to evaluate these materials for rocket nozzle design. The material of this study is ATJ graphite, which is the candidate material for rocket nozzle throat. This study presents an experimental method to evaluate the thermal shock resistance and thermal shock fracture toughness of ATJ graphite using laser irradiation. In particular, thermal shock resistance tests are conducted with changes of specimen thickness, with laser source irradiated at the center of the specimen. Temperature distributions on the specimen surface are detected using type K and C thermocouples. Scanning electron microscope (SEM) is used to observe the thermal cracks on specimen surface

  18. Influence of recrystallization on thermal shock resistance of various tungsten grades

    International Nuclear Information System (INIS)

    Uytdenhouwen, I.; Decreton, M.; Hirai, T.; Linke, J.; Pintsuk, G.; Oost, G. van

    2007-01-01

    Thermal shock resistance of various tungsten grades (different manufacturing technologies and heat treatments) was examined under plasma disruption conditions, especially in the cracking regime, i.e. below the melting threshold. The tests have been simulated with the electron beam test facility JUDITH. The comparison of the thermal shock resistance showed that sintered tungsten appeared to be better than the deformed tungsten material and clear degradation after recrystallization was found. Damage processes linked to the mechanical properties of W are discussed

  19. Thermal shock behaviour of different tungsten grades under varying conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, Oliver Marius

    2012-07-19

    Thermonuclear fusion power plants are a promising option to ensure the energy supply for future generations, but in many fields of research enormous challenges have to be faced. A major step on the way to the prototype fusion reactor DEMO will be ITER which is build in Cadarache, southern France. One of the most critical issues is the field of in-vessel materials and components, in particular the plasma facing materials (PFM). PFMs that will be used in a device like ITER have to withstand severe environmental conditions in terms of steady state and transient thermal loads as well as high particle fluxes such as hydrogen, helium and neutrons. Candidate wall materials are beryllium, tungsten and carbon based materials like CFC (carbon fibre composite). Tungsten is the most promising material for an application in the divertor region with very severe loading conditions and it will most probably also be used as PFM for DEMO. Hence, this work focuses on the investigation of the thermal shock response of different tungsten grades in order to understand the damage mechanisms and to identify material parameters which influence this behaviour under ITER and DEMO relevant operation conditions. Therefore the microstructure and the mechanical and thermal properties of five industrially manufactured tungsten grades were characterised. All five tungsten grades were exposed to transient thermal events with very high power densities of up to 1.27 GWm{sup -2} at varying base temperatures between RT and 600 C in the electron beam device JUDITH 1. The pulse numbers were limited to a maximum of 1000 in order to avoid immoderate workload on the test facility and to have enough time to cover a wide range of loading conditions. The results of this damage mapping enable to define different damage and cracking thresholds for the investigated tungsten grades and to identify certain material parameters which influence the location of these thresholds and the distinction of the induced

  20. Thermal shock behaviour of different tungsten grades under varying conditions

    International Nuclear Information System (INIS)

    Wirtz, Oliver Marius

    2012-01-01

    Thermonuclear fusion power plants are a promising option to ensure the energy supply for future generations, but in many fields of research enormous challenges have to be faced. A major step on the way to the prototype fusion reactor DEMO will be ITER which is build in Cadarache, southern France. One of the most critical issues is the field of in-vessel materials and components, in particular the plasma facing materials (PFM). PFMs that will be used in a device like ITER have to withstand severe environmental conditions in terms of steady state and transient thermal loads as well as high particle fluxes such as hydrogen, helium and neutrons. Candidate wall materials are beryllium, tungsten and carbon based materials like CFC (carbon fibre composite). Tungsten is the most promising material for an application in the divertor region with very severe loading conditions and it will most probably also be used as PFM for DEMO. Hence, this work focuses on the investigation of the thermal shock response of different tungsten grades in order to understand the damage mechanisms and to identify material parameters which influence this behaviour under ITER and DEMO relevant operation conditions. Therefore the microstructure and the mechanical and thermal properties of five industrially manufactured tungsten grades were characterised. All five tungsten grades were exposed to transient thermal events with very high power densities of up to 1.27 GWm -2 at varying base temperatures between RT and 600 C in the electron beam device JUDITH 1. The pulse numbers were limited to a maximum of 1000 in order to avoid immoderate workload on the test facility and to have enough time to cover a wide range of loading conditions. The results of this damage mapping enable to define different damage and cracking thresholds for the investigated tungsten grades and to identify certain material parameters which influence the location of these thresholds and the distinction of the induced damages

  1. Ductile fracture estimation of reactor pressure vessel under thermal shock

    International Nuclear Information System (INIS)

    Takahashi, Jun; Sakai, Shinsuke; Okamura, Hiroyuki

    1990-01-01

    This paper presents a new scheme for the estimation of unstable ductile fracture of a reactor pressure vessel under thermal shock conditions. First, it is shown that the bending moment applied to the cracked section can be evaluated by considering the plastic deformation of the cracked section and the thermal deformation of the shell. As the contribution of the local thermal stress to the J-value is negligible, the J-value under thermal shock can be easily evaluated by using fully plastic solutions for the cracked part. Next, the phenomena of ductile fracture under thermal shock are expressed on the load-versus-displacement diagram which enables us to grasp the transient phenomena visually. In addition, several parametrical surveys are performed on the above diagram concerning the variation of (1) thermal shock conditions, (2) initial crack length, and (3) J-resistance curve (i.e. embrittlement by neutron irradiation). (author)

  2. Thermal shock effect on Mechanical and Physical properties of pre-moisture treated GRE composite

    Science.gov (United States)

    Chakraverty, A. P.; Panda, A. B.; Mohanty, U. K.; Mishra, S. C.; Biswal, B. B.

    2018-03-01

    Many practical situations may be encountered under which a GFRP (Glass fibre reinforced polymer) composite, during its service life, is exposed to the severities of sudden temperature fluctuations. Moisture absorption of GRE (Glass fibre reinforced epoxy) composites followed by various gradients of temperature fluctuations may cause thermo- mechanical degradation. It is on this context, the hand layed GRE composite samples are exposed to up-thermal shock (-40°C to +50°C) and down-thermal shock (+50°C to -40°C) for various time interval after several periods of moisture (hydrothermal/hygrothermal) conditioning. The thermally shocked GRE specimens are put to 3-point bend test to divulge inter laminar shear strength (ILSS). Least ILSS values are recorded for the samples with maximum period of moisture treatments under with both up-thermal and down-thermal shock conditions. Lower glass transition temperature (Tg) values, as revealed through the low temperature DSC test, are exhibited at maximum durations of both up-thermal and down-thermal shock for the samples with higher periods of hygrothermal/hydrothermal treatments. SEM fractographs of representative GRE specimens after optimum period of moisture treatments and thermal shock show the various modes of failures.

  3. Thermomechanical fields measurement for fatigue investigation under cyclic thermal shocks

    International Nuclear Information System (INIS)

    Charbal, Ali

    2017-01-01

    Thermal fatigue occurs in nuclear power plant pipes. The temperature variations are due to the turbulent mixing of fluids that have different temperatures. Many experimental setups have been designed but the measured temperatures have only been punctual and out of the zone of interest (e.g., via thermocouples). The equivalent strain variation in the crack initiation region is calculated with numerical thermomechanical simulations. In many cases, the comparisons between numerical and experimental results have shown that the crack initiation predictions in thermal fatigue are non-conservative. a new testing setup is proposed where thermal shocks are applied with a pulsed laser beam while the thermal and kinematic fields on the specimen surface are measured with infrared (IR) and visible cameras, respectively. Experimental testings are performed and different measurement techniques for temperature and kinematic fields are used. IR camera and pyrometers allow to measure the temperature variations in the zone impacted by the laser beam. To estimate the absolute temperature, the surface emissivities at the respective wavelengths are determined by different methods. The absolute temperature field is then used to apply the actual thermal loading in a decoupled FE model after an identification process of the parameters of the laser beam. Once the thermal loading is generated based upon the experimental data, the stress and strain fields can be computed in the region of interest with an elastoplastic law.The experimental strain variations calculated from the DIC measurements are compared with the predictions obtained with the FE simulation. (author) [fr

  4. Thermal shock fatigue behavior of TiC/Al2O3 composite ceramics

    Institute of Scientific and Technical Information of China (English)

    SI Tingzhi; LIU Ning; ZHANG Qingan; YOU Xianqing

    2008-01-01

    The thermal shock fatigue behaviors of pure hot-pressed alumina and 30 wt. % TiC/Al2O3 composites were studied. The effect of TiC and Al2O3 starting particle size on the mechanical properties of the composites was discussed. Indentation-quench test was conducted to evaluate the effect of thermal fatigue temperature difference (ΔT) and number of thermal cycles (N) on fatigue crack growth (Δα). The mechanical properties and thermal fatigue resistance of TiC/Al2O3 composites are remarkably improved by the addition of TiC. The thermal shock fatigue of monolithic alumina and TiC/Al2O3 composites is due to a "true" cycling effect (thermal fatigue). Crack deflection and bridging are the predominant reasons for the improvement of thermal shock fatigue resistance of the composites.

  5. Thermal Shock Property of Al/Ni-ZrO2 Gradient Thermal Barrier Coatings

    Institute of Scientific and Technical Information of China (English)

    FANJin-juan; WANGQuan-sheng; ZHANGWei-fang

    2004-01-01

    Al/Ni-ZrO2 gradient thermal barrier coatings are made on aluminum substrate using plasma spraying method and one direction thermal shock properties of the coatings are studied in this paper. The results show that pores in coatings link to form cracks vertical to coating surface. They go through the whole ZrO2 coating once vertical cracks form. When thermal shock cycles increase, horizontal cracks that result in coatings failure forms in the coatings and interface. And vertical cracks delay appearance of horizontal cracks and enhance thermal shock property of coatings. Failure mechanisms of coating thermal shock are discussed using experiments and finite element method.

  6. Ouellette Thermal Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Thermal Test Facility is a joint Army/Navy state-of-the-art facility (8,100 ft2) that was designed to:Evaluate and characterize the effect of flame and thermal...

  7. The elevated temperature and thermal shock fracture toughnesses of nuclear pressure vessel steel

    International Nuclear Information System (INIS)

    Hirano, Kazumi; Kobayashi, Hideo; Nakazawa, Hajime; Nara, Atsushi.

    1979-01-01

    Thermal shock experiments were conducted on nuclear pressure vessel steel A533 Grade B Class 1. Elastic-plastic fracture toughness tests were carried out within the same high temperature range of the thermal shock experiment and the relation between stretched zone width, SZW and J-integral was clarified. An elastic-plastic thermal shock fracture toughness value. J sub(tsc) was evaluated from a critical value of stretched zone width, SZW sub(tsc) at the initiation of thermal shock fracture by using the relation between SZW and J. The J sub(tsc) value was compared with elastic-plastic fracture toughness values, J sub( ic), and the difference between the J sub(tsc) and J sub( ic) values was discussed. The results obtained are summarized as follows; (1) The relation between SZW and J before the initiation of stable crack growth in fracture toughness test at a high temperature can be expressed by the following equation regardless of test temperature, SZW = 95(J/E), where E is Young's modulus. (2) Elevated temperature fracture toughness values ranging from room temperature to 400 0 C are nearly constant regardless of test temperature. It is confirmed that upper shelf fracture toughness exists. (3) Thermal shock fracture toughness is smaller than elevated temperature fracture toughness within the same high temperature range of thermal shock experiment. (author)

  8. Dynamic testing of adhesive joints using a shock testing machine

    NARCIS (Netherlands)

    Aanhold, J.E. van; Weersink, A.F.J.; Ludolphy, J.W.L.

    1998-01-01

    A light-weight shock testing machine, designed for type approval testing of naval equipment up to 300 kg mass, has been modified into a dynamic tensile test rig. This enables to test structural details for high rate dynamic tensile loadings such as occur during underwater shock. The maximum capacity

  9. Thermal shock problems of bonded structure for plasma facing components

    International Nuclear Information System (INIS)

    Shibui, M.; Kuroda, T.; Kubota, Y.

    1991-01-01

    Thermal shock tests have been performed on W(Re)/Cu and Mo/Cu duplex structures with a particular emphasis on two failure modes: failure on the heated surface and failure near the bonding interface. The results indicate that failure of the duplex structure largely depends on the constraint of thermal strain on the heated surface and on the ductility changes of armour materials. Rapid debonding of the bonding interface may be attributed to the yielding of armour materials. This leads to a residual bending deformation when the armour cools down. Arguments are also presented in this paper on two parameter characterization of the failure of armour materials and on stress distribution near the free edge of the bonding interface. (orig.)

  10. Basic thermal-mechanical properties and thermal shock, fatigue resistance of swaged + rolled potassium doped tungsten

    Science.gov (United States)

    Zhang, Xiaoxin; Yan, Qingzhi; Lang, Shaoting; Xia, Min; Ge, Changchun

    2014-09-01

    The potassium doped tungsten (W-K) grade was achieved via swaging + rolling process. The swaged + rolled W-K alloy exhibited acceptable thermal conductivity of 159.1 W/m K and ductile-to-brittle transition temperature of about 873 K while inferior mechanical properties attributed to the coarse pores and small deformation degree. Then the thermal shock, fatigue resistance of the W-K grade were characterized by an electron beam facility. Thermal shock tests were conducted at absorbed power densities varied from 0.22 to 1.1 GW/m2 in a step of 0.22 GW/m2. The cracking threshold was in the range of 0.44-0.66 GW/m2. Furthermore, recrystallization occurred in the subsurface of the specimens tested at 0.66-1.1 GW/m2 basing on the analysis of microhardness and microstructure. Thermal fatigue tests were performed at 0.44 GW/m2 up to 1000 cycles and no cracks emerged throughout the tests. Moreover, recrystallization occurred after 1000 cycles.

  11. Thermal analysis of a mix up sodium tank and its ebb pipeline for SS-050 circuit during a thermal shock

    International Nuclear Information System (INIS)

    Jesus Miranda, C.A. de; Gebrim, A.N.

    1988-12-01

    In this work a thermo-hydraulic model was developed in order to obtain the sodium temperature time history between the mixup tank (TM) and the drain tank of the SS-050 sodium test loop. Results are presented relative to a thermal shock whith initial and final sodium inlet temperature of 600 0 C and 400 0 C respectively, with a thermal gradient of-200 0 C/s. This sodium loop will be briefly installed in the IEN/RJ area. From the sodium temperature time-history during the thermal shock transient the temperature field for the walls of the TM bottom and outlet nozzle is obtained. (author) [pt

  12. 33 CFR 183.584 - Shock test.

    Science.gov (United States)

    2010-07-01

    ... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.584 Shock test. A fuel tank is tested by... the boat, apply 1000 cycles of 25g vertical accelerations at a rate of 80 cycles or less per minute... manufactured for installation with its center of gravity aft of the half length of the boat, apply 1000 cycles...

  13. Thermal properties and thermal shock resistance of liquid phase sintered ZrC-Mo cermets

    International Nuclear Information System (INIS)

    Landwehr, Sean E.; Hilmas, Gregory E.; Fahrenholtz, William G.; Talmy, Inna G.; Wang Hsin

    2009-01-01

    The linear thermal expansion coefficient (CTE), heat capacity, and thermal conductivity, were investigated as a function of temperature for hot pressed ZrC and liquid phase sintered ZrC-Mo cermets. The ZrC and the ZrC-Mo cermets had the same CTE at 50 deg. C (∼5.1-5.5 ppm deg. C -1 ), but the CTE of ZrC increased to ∼12.2 ppm deg. C -1 at 1000 deg. C compared to ∼7.2-8.5 ppm deg. C -1 for the ZrC-Mo cermets. Heat capacity was calculated using a rule of mixtures and previously reported thermodynamic data. Thermal diffusivity was measured with a laser flash method and was, in turn, used to calculate thermal conductivity. Thermal conductivity increased linearly with increasing temperature for all compositions and was affected by solid solution formation and carbon deficiency of the carbide phases. Hot pressed ZrC had the highest thermal conductivity (∼30-37 W m -1 K -1 ). The nominally 20 and 30 vol% Mo compositions of the ZrC-Mo cermets had a lower thermal conductivity, but the thermal conductivity generally increased with increasing Mo content. Water quench thermal shock testing showed that ZrC-30 vol% Mo had a critical temperature difference of 350 deg. C, which was ∼120 deg. C higher than ZrC. This increase was due to the increased toughness of the cermet compared to ZrC.

  14. Small-Scale Shock Testing of Propellants and Ingredients

    National Research Council Canada - National Science Library

    Dawley, S

    2004-01-01

    .... The use of small-scale gap testing to evaluate the shock sensitivity of individual propellant ingredients and propellant formulations is a valuable method for experimentally establishing shock...

  15. Evaluation of thermal shock resistance of cordierite honeycombs

    Indian Academy of Sciences (India)

    A comparative study on thermal shock resistance (TSR) of extruded cordierite honeycombs is presented. TSR is an important property that predicts the life of these products in thermal environments used for automobile pollution control as catalytic converter or as diesel particulate filter. TSR was experimentally studied by ...

  16. Evaluation of the of thermal shock resistance of a castable containing andalusite aggregates by thermal shock cycles

    International Nuclear Information System (INIS)

    Garcia, G.C.R.; Santos, E.M.B.; Ribeiro, S.; Rodrigues, J.A.

    2011-01-01

    The thermal shock resistance of refractory materials is one of the most important characteristics that determine their performance in many applications, since abrupt and drastic differences in temperature can damage them. Resistance to thermal shock damage can be evaluated based on thermal cycles, i.e., successive heating and cooling cycles followed by an analysis of the drop in Young's modulus occurring in each cycle. The aim of this study was to evaluate the resistance to thermal shock damage in a commercial refractory concrete with andalusite aggregate. Concrete samples that were sintered at 1000 deg C and 1450 deg C for 5 hours to predict and were subjected to 30 thermal shock cycles, soaking in the furnace for 20 minutes at a temperature of 1000 deg C, and subsequent cooling in circulating water at 25 deg C. The results showed a decrease in Young's modulus and rupture around 72% for samples sintered at 1000 ° C, and 82% in sintered at 1450 ° C. The refractory sintered at 1450 deg C would show lower thermal shock resistance than the refractory sintered at 1000 deg C. (author)

  17. Thermal shock behavior of rare earth modified alumina ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junlong; Liu, Changxia [Ludong Univ., Yantai (China). School of Transportation

    2017-05-15

    Alumina matrix ceramic composites toughened by AlTiC master alloys, diopside and rare earths were fabricated by hot-pressing and their thermal shock behavior was investigated and compared with that of monolithic alumina. Results showed that the critical thermal shock temperature (ΔT) of monolithic alumina was 400 C. However, it decreased to 300 C for alumina incorporating only AlTiC master alloys, and increased with further addition of diopside and rare earths. Improvement of thermal shock resistance was obtained for alumina ceramic composites containing 9.5 wt.% AlTiC master alloys and 0.5 wt.% rare earth additions, which was mainly attributed to the formation of elongated grains in the composites.

  18. Thermal shock resistance of ceramic fibre composites characterized by non-destructive methods

    Directory of Open Access Journals (Sweden)

    M. Dimitrijević

    2008-12-01

    Full Text Available Alumina based ceramic fibres and alumina based ceramic were used to produce composite material. Behaviour of composite ceramics after thermal shock treatments was investigated. Thermal shock of the samples was evaluated using water quench test. Surface deterioration level of samples was monitored by image analysis before and after a number of quenching cycles. Ultrasonic measurements were done on samples after quench tests. Dynamic Young modulus of elasticity and strength degradation were calculated using measured values of ultrasonic velocities. Strengths deterioration was calculated using the non-destructive measurements and correlated to degradation of surface area and number of quenches. The addition of small amount of ceramic fibres improves the strengths and diminishes the loss of mechanical properties of samples during thermal shock experiments.

  19. Thermal test options

    International Nuclear Information System (INIS)

    Koski, J.A.; Keltner, N.R.; Sobolik, K.B.

    1993-02-01

    Shipping containers for radioactive materials must be qualified to meet a thermal accident environment specified in regulations, such at Title 10, Code of Federal Regulations, Part 71. Aimed primarily at the shipping container design, this report discusses the thermal testing options available for meeting the regulatory requirements, and states the advantages and disadvantages of each approach. The principal options considered are testing with radiant heat, furnaces, and open pool fires. The report also identifies some of the facilities available and current contacts. Finally, the report makes some recommendations on the appropriate use of these different testing methods

  20. Crack propagation behavior of TiN coatings by laser thermal shock experiments

    International Nuclear Information System (INIS)

    Choi, Youngkue; Jeon, Seol; Jeon, Min-seok; Shin, Hyun-Gyoo; Chun, Ho Hwan; Lee, Youn-seoung; Lee, Heesoo

    2012-01-01

    Highlights: ► The crack propagation behavior of TiN coating after laser thermal shock experiment was observed by using FIB and TEM. ► Intercolumnar cracks between TiN columnar grains were predominant cracking mode after laser thermal shock. ► Cracks were propagated from the coating surface to the substrate at low laser pulse energy and cracks were originated at coating-substrate interface at high laser pulse energy. ► The cracks from the interface spread out transversely through the weak region of the columnar grains by repetitive laser shock. - Abstract: The crack propagation behavior of TiN coatings, deposited onto 304 stainless steel substrates by arc ion plating technique, related to a laser thermal shock experiment has been investigated using focused ion beam (FIB) and transmission electron microscopy (TEM). The ablated regions of TiN coatings by laser ablation system have been investigated under various conditions of pulse energies and number of laser pulses. The intercolumnar cracks were predominant cracking mode following laser thermal shock tests and the cracks initiated at coating surface and propagated in a direction perpendicular to the substrate under low loads conditions. Over and above those cracks, the cracks originated from coating-substrate interface began to appear with increasing laser pulse energy. The cracks from the interface also spread out transversely through the weak region of the columnar grains by repetitive laser shock.

  1. Thermal Testing Measurements Report

    Energy Technology Data Exchange (ETDEWEB)

    R. Wagner

    2002-09-26

    The purpose of the Thermal Testing Measurements Report (Scientific Analysis Report) is to document, in one report, the comprehensive set of measurements taken within the Yucca Mountain Project Thermal Testing Program since its inception in 1996. Currently, the testing performed and measurements collected are either scattered in many level 3 and level 4 milestone reports or, in the case of the ongoing Drift Scale Test, mostly documented in eight informal progress reports. Documentation in existing reports is uneven in level of detail and quality. Furthermore, while all the data collected within the Yucca Mountain Site Characterization Project (YMP) Thermal Testing Program have been submitted periodically to the Technical Data Management System (TDMS), the data structure--several incremental submittals, and documentation formats--are such that the data are often not user-friendly except to those who acquired and processed the data. The documentation in this report is intended to make data collected within the YMP Thermal Testing Program readily usable to end users, such as those representing the Performance Assessment Project, Repository Design Project, and Engineered Systems Sub-Project. Since either detailed level 3 and level 4 reports exist or the measurements are straightforward, only brief discussions are provided for each data set. These brief discussions for different data sets are intended to impart a clear sense of applicability of data, so that they will be used properly within the context of measurement uncertainty. This approach also keeps this report to a manageable size, an important consideration because the report encompasses nearly all measurements for three long-term thermal tests. As appropriate, thermal testing data currently residing in the TDMS have been reorganized and reformatted from cumbersome, user-unfriendly Input-Data Tracking Numbers (DTNs) into a new set of Output-DTNs. These Output-DTNs provide a readily usable data structure

  2. Dynamic testing of airplane shock-absorbing struts

    Science.gov (United States)

    Langer, P; Thome, W

    1932-01-01

    Measurement of perpendicular impacts of a landing gear with different shock-absorbing struts against the drum testing stand. Tests were made with pneumatic shock absorbers having various degrees of damping, liquid shock absorbers, steel-spring shock absorbers and rigid struts. Falling tests and rolling tests. Maximum impact and gradual reduction of the impacts in number and time in the falling tests. Maximum impact and number of weaker impacts in rolling tests.

  3. Microstructure Evolution and Impedance Spectroscopy Characterization of Thermal Barrier Coating Exposed to Gas Thermal-shock Environment

    Directory of Open Access Journals (Sweden)

    CHEN Wen-long

    2017-10-01

    Full Text Available Gas thermal-shock experiment of thermal barrier coatings (TBCs was carried out in air up to 1250℃ in order to simulate the thermal cycling process of the engine blades during the start heating and shut down cooling. The growth of thermal growth oxide (TGO layer and microstructure evolution of YSZ layer during thermal cycling process were investigated systematically by electrochemical impedance spectroscopy testing and SEM. The results show that the thickness of TGO layer increases when increasing the frequency of thermal cycling, and the impedance response of middle frequencies is more and more remarkable. Meanwhile, initiation and growth of micro-cracks occur in YSZ layer during the gas thermal-shock experiment. The corresponding impedance characterization of YSZ layer after 100 cycles is similar to the as-sprayed sample, indicating that micro-cracks in short time could heal since the YSZ micro-cracks sinter at high temperature. But after 300 cycles, the impedance spectroscopy of YSZ layer is quite different to the as-sprayed sample, with the corresponding impedance of particle-gap of YSZ more and more remarkable with the increase of the thermal-shock times, indicating that non-healing micro-cracks form in the YSZ layer, which may be the main reason to induce the failure of YSZ layer.

  4. An alternative method for performing pressurized thermal shock analysis

    International Nuclear Information System (INIS)

    Bishop, B.A.; Meyer, T.A.; Carter, R.G.; Gamble, R.M.

    1997-01-01

    This paper describes how Probability of Crack Initiation and acceptable Pressurized Thermal Shock frequency were correlated with a c and summarizes several example applications, including evaluation of potential plant modifications. Plans for an industry supported pilot-plant application of the alternative Probabilistic Fracture Mechanics method for RG 1.154 are also discussed. 9 refs, 4 figs, 1 tab

  5. Pressurized thermal shock evaluation of RPV-Stade

    International Nuclear Information System (INIS)

    Blauel, J.G.; Hodulak, L.; Siegele, D.; Nagel, G.; Hertlein, D.

    1997-01-01

    The presentation overviews the following issues: thermal shock analysis (thermohydraulics, temperatures and stresses, crack tip field parameters, cladding influence, methodology of fracture mechanics assessment); EOL safety evaluation for RPV Stade (initial conditions and input data, fracture toughness, load path diagrams, warm prestress effect, crack arrest, remaining load carrying capacity)

  6. Pressurized-thermal-shock experiments with thick vessels

    International Nuclear Information System (INIS)

    Bryan, R.H.; Nanstad, R.K.; Merkle, J.G.; Robinson, G.C.; Whitman, G.D.

    1986-01-01

    Information is provided on the series of pressurized-thermal-shock experiments at the Oak Ridge National Laboratory, motivated by a concern for the behavior of flaws in reactor pressure vessels having welds or shells exhibiting low upper-shelf Charpy impact energies, approx. 68J or less

  7. Thermal shock behaviour of mullite-cordierite refractory materials

    Czech Academy of Sciences Publication Activity Database

    Boccaccini, D. N.; Leonelli, C.; Romagnoli, M.; Pellacani, G. C.; Veronesi, P.; Dlouhý, Ivo; Boccaccini, A. R.

    2007-01-01

    Roč. 106, č. 3 (2007), s. 142-148 ISSN 1743-6753 R&D Projects: GA AV ČR IAA200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : refraktory materials * thermal shock * fracutre toughness Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.074, year: 2007

  8. Pressurized thermal shock evaluation of RPV-Stade

    Energy Technology Data Exchange (ETDEWEB)

    Blauel, J G; Hodulak, L; Siegele, D [Fraunhofer-Institut fuer Werkstoffmechanik, Freiburg im Breisgau (Germany); Nagel, G [PreussenElektra AG, Hannover (Germany); Hertlein, D [Siemens AG Unternehmensbereich KWU, Erlangen (Germany)

    1997-09-01

    The presentation overviews the following issues: thermal shock analysis (thermohydraulics, temperatures and stresses, crack tip field parameters, cladding influence, methodology of fracture mechanics assessment); EOL safety evaluation for RPV Stade (initial conditions and input data, fracture toughness, load path diagrams, warm prestress effect, crack arrest, remaining load carrying capacity).

  9. An alternative method for performing pressurized thermal shock analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, B A; Meyer, T A [Westinghouse Energy Systems, Pittsburgh, PA (United States); Carter, R G [Electric Power Research Inst., Charlotte, NC (United States); Gamble, R M [Sartrex Corp., Rockville, MD (United States)

    1997-09-01

    This paper describes how Probability of Crack Initiation and acceptable Pressurized Thermal Shock frequency were correlated with a{sub c} and summarizes several example applications, including evaluation of potential plant modifications. Plans for an industry supported pilot-plant application of the alternative Probabilistic Fracture Mechanics method for RG 1.154 are also discussed. 9 refs, 4 figs, 1 tab.

  10. Some numerical approaches of creep, thermal shock, damage

    Indian Academy of Sciences (India)

    Creep can be satisfactorily described by a kinematic hardening, and exhibits different creep rates in tension and compression. Concerning the thermal shock of materials, the numerical approach depends whether or not the material is able to develop a sprayed out damage, leading to micro- or macro-cracking. Finally ...

  11. A comparative analysis of reticular crack on ceramic plate driven by thermal shock

    Science.gov (United States)

    Xu, XiangHong; Sheng, ShiLong; Tian, Cheng; Yuan, WenJun

    2016-07-01

    Reticular crack is generally found on the surface of ceramic material that has been subjected to a thermal-shock condition. In the present study, a quantitative effect of thermal shock and quench temperature has been studied and investigated. Experimental tests were carried out to characterize the reticular crack that has been found in the Ge Kiln, which is a famous art of the ancient Chinese culture. After comparative analysis between thermal-shock cracks and the glaze crack patterns of the Ge Kiln porcelain, it is found that this study is expected to provide a powerful tool for recurrence of the long-lost firing and cooling process of the Ge Kiln porcelain.

  12. Residual stress evolution regularity in thermal barrier coatings under thermal shock loading

    Directory of Open Access Journals (Sweden)

    Ximin Chen

    2014-01-01

    Full Text Available Residual stress evolution regularity in thermal barrier ceramic coatings (TBCs under different cycles of thermal shock loading of 1100°C was investigated by the microscopic digital image correlation (DIC and micro-Raman spectroscopy, respectively. The obtained results showed that, as the cycle number of the thermal shock loading increases, the evolution of the residual stress undergoes three distinct stages: a sharp increase, a gradual change, and a reduction. The extension stress near the TBC surface is fast transformed to compressive one through just one thermal cycle. After different thermal shock cycles with peak temperature of 1100°C, phase transformation in TBC does not happen, whereas the generation, development, evolution of the thermally grown oxide (TGO layer and micro-cracks are the main reasons causing the evolution regularity of the residual stress.

  13. Revisiting the thermal effect on shock wave propagation in weakly ionized plasmas

    International Nuclear Information System (INIS)

    Zhou, Qianhong; Dong, Zhiwei; Yang, Wei

    2016-01-01

    Many researchers have investigated shock propagation in weakly ionized plasmas and observed the following anomalous effects: shock acceleration, shock recovery, shock weakening, shock spreading, and splitting. It was generally accepted that the thermal effect can explain most of the experimental results. However, little attention was paid to the shock recovery. In this paper, the shock wave propagation in weakly ionized plasmas is studied by fluid simulation. It is found that the shock acceleration, weakening, and splitting appear after it enters the plasma (thermal) region. The shock splits into two parts right after it leaves the thermal region. The distance between the splitted shocks keeps decreasing until they recover to one. This paper can explain a whole set of features of the shock wave propagation in weakly ionized plasmas. It is also found that both the shock curvature and the splitting present the same photoacoustic deflection (PAD) signals, so they cannot be distinguished by the PAD experiments.

  14. Experimental analysis of the evolution of thermal shock damage using transit time measurement of ultrasonic waves

    NARCIS (Netherlands)

    Damhof, F.; Brekelmans, W.A.M.; Geers, M.G.D.

    2009-01-01

    Thermal shock is a principal cause of catastrophic wear of the refractory lining of high temperature installations in metal making processes. To investigate thermal shock experimentally with realistic and reproducible heat transfer conditions, chamotte and corund refractory samples of ambient

  15. Thermal shock resistance of thick boron-doped diamond under extreme heat loads

    NARCIS (Netherlands)

    De Temmerman, G.; Dodson, J.; Linke, J.; Lisgo, S.; Pintsuk, G.; Porro, S.; Scarsbrook, G.

    2011-01-01

    Thick free-standing boron-doped diamonds were prepared by microwave plasma assisted chemical vapour deposition. Samples with a final thickness close to 5 mm and with lateral dimensions 25 x 25 mm were produced. The thermal shock resistance of the material was tested by exposure in the JUDITH

  16. Surface flaw in a thermally shocked hollow cylinder

    International Nuclear Information System (INIS)

    Kobayashi, A.S.; Emery, A.F.; Polvanich, N.; Love, W.J.

    1975-01-01

    The objective of this paper is to illustrate a procedure for estimating the stress intensity factors of a semi-elliptical crack located in the inner or outer surface of a thermally shocked hollow cylinder. The first step in this procedure is to estimate the transient thermal elastic stresses induced by sudden cooling of an uncracked cylinder by numerically evaluating standard heat transfer and thermal stress formulae. The stresses at the location of the crack surface in the uncracked cylinder are eliminated by the method of superposition in order to obtain a stress free crack surface. The stress intensity factors are then determined by a judicious use of two sets of solutions, one set involving stress intensity factors for a semi-elliptical crack in a flat plate and subjected to a polynomial distribution of pressure loading, and another set involving single-edge notched plates with prescribed edge-displacements and single-edge internally or externally notched cylinders with thermal shock loading. The former solutions are determined by the alternating technique in three-dimensional fracture mechanics with a fourth order polynomial pressure distribution on the crack surface where both the front and back surface effects are accounted for. The latter solutions involve two-dimensional finite element solutions of single-edge notched plates with prescribed edge-displacements and single-edge notched cylinders with thermal shock loading. By comparing these two two-dimensional solutions, an estimate of the effect of the cylindrical curvature on an edge-cracked plate is obtained. The combination of these two sets of solutions thus yields an estimate of the stress intensity factor in an internal and external semi-elliptical crack in a thermally shocked cylinder

  17. Shock wave collisions and thermalization in AdS5

    International Nuclear Information System (INIS)

    Kovchegov, Yuri V.

    2011-01-01

    We study heavy ion collisions at strong 't Hooft coupling using AdS/CFT correspondence. According to the AdS/CFT dictionary heavy ion collisions correspond to gravitational shock wave collisions in AdS 5 . We construct the metric in the forward light cone after the collision perturbatively through expansion of Einstein equations in graviton exchanges. We obtain an analytic expression for the metric including all-order graviton exchanges with one shock wave, while keeping the exchanges with another shock wave at the lowest order. We read off the corresponding energy-momentum tensor of the produced medium. Unfortunately this energy-momentum tensor does not correspond to ideal hydrodynamics, indicating that higher order graviton exchanges are needed to construct the full solution of the problem. We also show that shock waves must completely stop almost immediately after the collision in AdS 5 , which, on the field theory side, corresponds to complete nuclear stopping due to strong coupling effects, likely leading to Landau hydrodynamics. Finally, we perform trapped surface analysis of the shock wave collisions demonstrating that a bulk black hole, corresponding to ideal hydrodynamics on the boundary, has to be created in such collisions, thus constructing a proof of thermalization in heavy ion collisions at strong coupling. (author)

  18. Thermal shock properties of 2D-SiCf/SiC composites

    International Nuclear Information System (INIS)

    Lee, Sang Pill; Lee, Jin Kyung; Son, In Soo; Bae, Dong Su; Kohyama, Akira

    2012-01-01

    This paper dealt with the thermal shock properties of SiC f /SiC composites reinforced with two dimensional SiC fabrics. SiC f /SiC composites were fabricated by a liquid phase sintering process, using a commercial nano-size SiC powder and oxide additive materials. An Al 2 O 3 –Y 2 O 3 –SiO 2 powder mixture was used as a sintering additive for the consolidation of SiC matrix region. In this composite system, Tyranno SA SiC fabrics were also utilized as a reinforcing material. The thermal shock test for SiC f /SiC composites was carried out at the elevated temperature. Both mechanical strength and microstructure of SiC f /SiC composites were investigated by means of optical microscopy, SEM and three point bending test. SiC f /SiC composites represented a dense morphology with a porosity of about 8.2% and a flexural strength of about 160 MPs. The characterization of SiC f /SiC composites was greatly affected by the history of cyclic thermal shock. Especially, SiC f /SiC composites represented a reduction of flexural strength at the thermal shock temperature difference higher than 800 °C.

  19. Test design requirements: Thermal conductivity probe testing

    International Nuclear Information System (INIS)

    Heath, R.E.

    1985-01-01

    This document establishes the test design requirements for development of a thermal conductivity probe test. The thermal conductivity probe determines in situ thermal conductivity using a line source transient heat conduction analysis. This document presents the rationale for thermal conductivity measurement using a thermal conductivity probe. A general test description is included. Support requirements along with design constraints are detailed to allow simple design of the thermal conductivity probe and test. The schedule and delivery requirements of the responsible test designer are also included. 7 refs., 1 fig

  20. Basic thermal–mechanical properties and thermal shock, fatigue resistance of swaged + rolled potassium doped tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoxin; Yan, Qingzhi, E-mail: qzyan@ustb.edu.cn; Lang, Shaoting; Xia, Min; Ge, Changchun

    2014-09-15

    Highlights: • The potassium doped tungsten grade was achieved via swaging + rolling process. • The cracking threshold of the W–K alloy was in the range of 0.44–0.66 GW/m{sup 2}. • Recrystallization occurred at 0.66–1.1 GW/m{sup 2} during the thermal shock tests. • No cracks emerged during the thermal fatigue tests (0.44 GW/m{sup 2}, 1000 cycles). • Recrystallization occurred after 1000 cycles during the thermal fatigue tests. - Abstract: The potassium doped tungsten (W–K) grade was achieved via swaging + rolling process. The swaged + rolled W–K alloy exhibited acceptable thermal conductivity of 159.1 W/m K and ductile-to-brittle transition temperature of about 873 K while inferior mechanical properties attributed to the coarse pores and small deformation degree. Then the thermal shock, fatigue resistance of the W–K grade were characterized by an electron beam facility. Thermal shock tests were conducted at absorbed power densities varied from 0.22 to 1.1 GW/m{sup 2} in a step of 0.22 GW/m{sup 2}. The cracking threshold was in the range of 0.44–0.66 GW/m{sup 2}. Furthermore, recrystallization occurred in the subsurface of the specimens tested at 0.66–1.1 GW/m{sup 2} basing on the analysis of microhardness and microstructure. Thermal fatigue tests were performed at 0.44 GW/m{sup 2} up to 1000 cycles and no cracks emerged throughout the tests. Moreover, recrystallization occurred after 1000 cycles.

  1. Assessment of RANS CFD modelling for pressurised thermal shock analysis

    International Nuclear Information System (INIS)

    Sander M Willemsen; Ed MJ Komen; Sander Willemsen

    2005-01-01

    Full text of publication follows: The most severe Pressurised Thermal Shock (PTS) scenario is a cold water Emergency Core Coolant (ECC) injection into the cold leg during a LOCA. The injected ECC water mixes with the hot fluid present in the cold leg and flows towards the downcomer where further mixing takes place. When the cold mixture comes into contact with the Reactor Pressure Vessel (RPV) wall, it may lead to large temperature gradients and consequently to high stresses in the RPV wall. Knowledge of these thermal loads is important for RPV remnant life assessments. The existing thermal-hydraulic system codes currently applied for this purpose are based on one-dimensional approximations and can, therefore, not predict the complex three-dimensional flows occurring during ECC injection. Computational Fluid Dynamics (CFD) can be applied to predict these phenomena, with the ultimate benefit of improved remnant RPV life assessment. The present paper presents an assessment of various Reynolds Averaged Navier Stokes (RANS) CFD approaches for modeling the complex mixing phenomena occurring during ECC injection. This assessment has been performed by comparing the numerical results obtained using advanced turbulence models available in the CFX 5.6 CFD code in combination with a hybrid meshing strategy with experimental results of the Upper Plenum Test Facility (UPTF). The UPTF was a full-scale 'simulation' of the primary system of the four loop 1300 MWe Siemens/KWU Pressurised Water Reactor at Grafenrheinfeld. The test vessel upper plenum internals, downcomer and primary coolant piping were replicas of the reference plant, while other components, such as core, coolant pump and steam generators were replaced by simulators. From the extensive test programme, a single-phase fluid-fluid mixing experiment in the cold leg and downcomer was selected. Prediction of the mixing and stratification is assessed by comparison with the measured temperature profiles at several locations

  2. Thermal fluid mixing behavior during medium break LOCA in evaluation of pressurized thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jae Won; Bang, Young Seok; Seul, Kwang Won; Kim, Hho Jung [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    Thermal fluid mixing behavior during a postulated medium-size hot leg break loss of coolant accident is analyzed for the international comparative assessment study on pressurized thermal shock (PTS-ICAS) proposed by OECD-NEA. The applicability of RELAP5 code to analyze the thermal fluid mixing behavior is evaluated through a simple modeling relevant to the problem constraints. Based on the calculation result, the onset of thermal stratification is investigated using Theofanous`s empirical correlation. Sensitivity calculations using a fine node model and crossflow model are also performed to evaluate the modeling capability on multi-dimensional characteristics related to thermal fluid mixing. 6 refs., 8 figs. (Author)

  3. Thermal fluid mixing behavior during medium break LOCA in evaluation of pressurized thermal shock

    International Nuclear Information System (INIS)

    Jung, Jae Won; Bang, Young Seok; Seul, Kwang Won; Kim, Hho Jung

    1998-01-01

    Thermal fluid mixing behavior during a postulated medium-size hot leg break loss of coolant accident is analyzed for the international comparative assessment study on pressurized thermal shock (PTS-ICAS) proposed by OECD-NEA. the applicability of RELAP5 code to analyze the thermal fluid mixing behavior is evaluated through a simple modeling relevant to the problem constraints. Based on the calculation result, the onset of thermal stratification is investigated using Theofanous's empirical correlation. Sensitivity calculations using a fine node model and crossflow model are also performed to evaluate the modeling capability on multi-dimensional characteristics related to thermal fluid mixing

  4. Applications of the fundamental solution for a thermal shock on a finite orthotropic cylindrical thin shell

    International Nuclear Information System (INIS)

    Woo, H.K.; Huang, C.L.D.

    1979-01-01

    The authors investigate the temperature variations in a thin cylindrical shell of graphite materials with finite length, subjected to an instantaneous thermal shock. The solutions for the line source and the area source of thermal shock are obtained. Quasi-linear theory for heat transfer is assumed. Grades ATJ and ZTA graphite are used in the numerical examples. As is expected, the orthotropically thermal properties significantly affect the temperature variations in the shell due to the thermal shocks. (Auth.)

  5. Thermal Failure Analysis of Fiber-Reinforced Silica Aerogels under Liquid Nitrogen Thermal Shock

    Directory of Open Access Journals (Sweden)

    Ai Du

    2018-06-01

    Full Text Available Aerogel materials are recognized as promising candidates for the thermal insulator and have achieved great successes for the aerospace applications. However, the harsh environment on the exoplanet, especially for the tremendous temperature difference, tends to affect the tenuous skeleton and performances of the aerogels. In this paper, an evaluation method was proposed to simulate the environment of exoplanet and study the influence on the fiber-reinforced silica aerogels with different supercritical point drying (SPD technology. Thermal conductivity, mechanical property and the microstructure were characterized for understanding the thermal failure mechanism. It was found that structure and thermal property were significantly influenced by the adsorbed water in the aerogels under the thermal shocks. The thermal conductivity of CO2-SPD aerogel increased 35.5% after the first shock and kept in a high value, while that of the ethanol-SPD aerogel increased only 19.5% and kept in a relatively low value. Pore size distribution results showed that after the first shock the peak pore size of the CO2-SPD aerogel increased from 18 nm to 25 nm due to the shrinkage of the skeleton, while the peak pore size of the ethanol-SPD aerogel kept at ~9 nm probably induced by the spring-back effect. An 80 °C treatment under vacuum was demonstrated to be an effective way for retaining the good performance of ethanol-SPD aerogels under the thermal shock. The thermal conductivity increases of the ethanol-SPD aerogels after 5 shocks decreased from ~30 to ~0% via vacuum drying, while the increase of the CO2-SPD aerogels via the same treatments remains ~28%. The high-strain hardening and low-strain soften behaviors further demonstrated the skeleton shrinkage of the CO2-SPD aerogel.

  6. Electrochemical behaviour of a stainless steel coating after thermal fatigue and thermal shocks

    International Nuclear Information System (INIS)

    Boudebane, A.; Darsouni, A.; Chadli, H.; Boudebane, S.

    2012-01-01

    This work aims to study of the influence of thermal fatigue and thermal shock on the corrosion behaviour of coated steel AISI 304L. The coating was welded by TIG welding on specimens in ferritic-pearlitic steel grade AISI 4140. The study concerns three different states of deposit: sensitized, sensitized and strain hardened in surface and no sensitized. We realized electrochemical corrosion in an aqueous solution of NaCl 34 g/l. The corrosion of the specimens were evaluated by comparing the potentiodynamic curves for different states of the coating. Firstly, electrochemical characterization of deposits has shown a localized intergranular corrosion. Furthermore, the increase in the number of cycles of thermal fatigue accelerates the dissolution of deposit. Thermal shocks tend to improve resistance to corrosion. Against, the mechanical treatment of surfaces by burnishing decreases the dissolution rate of deposit cycles in thermal fatigue. (authors)

  7. Young’s modulus evaluation and thermal shock behavior of a porous SiC/cordierite composite material

    Directory of Open Access Journals (Sweden)

    Pošarac-Marković M.

    2015-01-01

    Full Text Available Porous SiC/Cordierite Composite Material with graphite content (10% was synthesized. Evaluation of Young modulus of elasticity and thermal shock behavior of these samples was presented. Thermal shock behavior was monitored using water quench test, and non destructive methods such are UPVT and image analysis were also used for accompaniment the level of destruction of the samples during water quench test. Based on the level of destruction graphical modeling of critical number of cycles was given. This approach was implemented on discussion of the influence of the graphite content on thermal stability behavior of the samples. [Projekat Ministarstva nauke Republike Srbije, br. III 45012

  8. Experiment and numerical analysis of the NPP pressurizer auxiliary spray line submitted to large thermal shocks

    International Nuclear Information System (INIS)

    Couterot, C.; Geyer, P.; Proix, J.M.

    1994-03-01

    The pressurizer auxiliary spray line of PWR nuclear power plants may be submitted to severe temperature transients during upset conditions: a 325 deg C cold thermal shock in one second is followed by a 200 deg C hot thermal shock. For such transients, the RCC-M French design code rules that prevent the ratcheting deformation hazard are not respected for the components with thickness transition. Consequently, Electricite de France has realized twenty thermal cycles under pressure on a representative mock-up. During these tests, many temperature, strain and diametral variations were measured. No significant ratcheting deformation was detected on all components, except on the 6'' x 2'' x 6'' T-piece, where a weak progressive diameter increase was observed during a few cycles. Moreover, computations of a 2'' socket welding were made with the non linear kinematic hardening Chaboche model which also showed a weak progressive deformation behaviour. (authors). 7 figs., 7 refs

  9. Pressurized Thermal Shock Analysis for OPR1000 Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, P. K.; Shamim, J. A.; Gairola, A.; Suh, Kune Y. [Seoul National Univ., Seoul (Korea, Republic of)

    2014-10-15

    The study provides a brief understanding of the analysis procedure and techniques using ANSYS, such as the acceptance criteria, selection and categorization of events, thermal analysis, structural analysis including fracture mechanics assessment, crack propagation and evaluation of material properties. PTS may result from instrumentation and control malfunction, inadvertent steam dump, and postulated accidents such as smallbreak (SB) LOCA, large-break (LB) LOCA, main steam line break (MSLB), feedwater line breaks and steam generator overfill. In this study our main focus is to consider only the LB LOCA due to a cold leg break of the Optimized Power Reactor 1000 MWe (OPR1000). Consideration is given as well to the emergency core cooling system (ECCS) specific sequence with the operating parameters like pressure, temperature and time sequences. The static structural and thermal analysis to investigate the effects of PTS on RPV is the main motivation of this study. Specific surface crack effects and its propagation is also considered to measure the integrity of the RPV. This study describes the procedure for pressurized thermal shock analysis due to a loss of coolant accidental condition and emergency core cooling system operation for reactor pressure vessel.. Different accidental events that cause pressurized thermal shock to nuclear RPV that can also be analyzed in the same way. Considering the limitations of low speed computer only the static analysis is conducted. The modified LBLOCA phases and simplified geometry can is utilized to analyze the effect of PTS on RPV for general understanding not for specific specialized purpose. However, by integrating the disciplines of thermal and structural analysis, and fracture mechanics analysis a clearer understanding of the total aspect of the PTS problem has resulted. By adopting the CFD, thermal hydraulics, uncertainties and risk analysis for different type of accidental conditions, events and sequences with proper

  10. Numerical evaluation of stress intensity factor for vessel and pipe subjected to thermal shock

    International Nuclear Information System (INIS)

    Kim, Y.W.; Lee, H.Y.; Yoo, B.

    1994-01-01

    The thermal weight function method and the finite element method were employed in the numerical computation of the stress intensity factor for a cracked vessel and the cracked pipe subjected to thermal shock. A wall subjected to thermal shock was analyzed, and it has been shown that the effect of thermal shock on the stress intensity factor is dominant for the crack with small crack length to thickness ratio. Convection at the crack face had an influence on the stress intensity factor in the early stage of thermal shock. (Author)

  11. Thermal-shock experiments with flawed clad cylinders

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Bryson, J.W.; Alexander, D.J.

    1989-01-01

    The life expectancy of LWR pressure vessels is influenced by a reduction in fracture toughness that is the result of radiation damage. As the fracture toughness decreases, the probability of propagation of preexisting flaws (sharp, crack-like defects) in the wall of the vessel increases. The probability of propagation is also influenced by the type of loading condition and the type of flaws that might exist. A loading condition of particular concern is referred to as pressurized thermal shock (PTS), and a flaw of particular concern for PTS loading conditions is a shallow surface flaw. A sudden cooling (thermal shock) of the inner surface of the vessel results in relatively high tensile stresses and relatively low fracture toughness at the inner surface. In addition, the attenuation of the fast-neutron fluence also results in relatively low fracture toughness at the inner surface. Under some circumstances, this combination of high stress and low toughness at the inner surface makes it possible for very shallow surface flaws to propagate. The PTS issue has been under investigation for quite some time, but thus far possible beneficial effects, other than thermal resistance, of the cladding on the inner surface of the vessel have not been included in the analysis of flaw behavior. This document discusses this effect of cladding on surface flaws and crack propagation

  12. Effect of severely thermal shocked MWCNT enhanced glass fiber reinforced polymer composite: An emphasis on tensile and thermal responses

    Science.gov (United States)

    Mahato, K. K.; Fulmali, A. O.; Kattaguri, R.; Dutta, K.; Prusty, R. K.; Ray, B. C.

    2018-03-01

    Fiber reinforced polymeric (FRP) composite materials are exposed to diverse changing environmental temperatures during their in-service period. Current investigation is aimed to investigate the influence of thermal-shock exposure on the mechanical behavior of multiwalled carbon nanotube (MWCNT) enhanced glass fiber reinforced polymeric (GFRP) composites. The samples were exposed to +70°C for 36 hrs followed by further exposure to ‑ 60°C for the similar interval of time. Tensile tests were conducted in order to evaluate the results of thermal-shock on the mechanical behavior of the neat and conditioned samples at 1 mm/min loading rate. The polymer phase i.e. epoxy was modified with various MWCNT content. The ultimate tensile strength (UTS) was raised by 15.11 % with increase in the 0.1 % MWCNT content GFRP as related to the thermal-shocked neat GFRP conditioned samples. The possible reason may be attributed to the variation in the coefficients of thermal expansion at the time of conditioning. Also, upto some extent the pre-existing residual stresses allows uniform distribution of stress and hence the reason in enhanced mechanical properties of GFRP and MWCNT filled composites. In order to access the modifications in the glass transition temperature (Tg) due to the addition of MWCNT in GFRP composite and also due to the thermal shock temperature modulated differential scanning calorimeter (TMDSC) measurements are carried out. Scanning electron microscopy(SEM) was carried out to identify different modes of failures and strengthening morphology in the composites.

  13. DNA extraction in Echinococcus granulosus and Taenia spp. eggs in dogs stool samples applying thermal shock.

    Science.gov (United States)

    Hidalgo, Alejandro; Melo, Angélica; Romero, Fernando; Hidalgo, Víctor; Villanueva, José; Fonseca-Salamanca, Flery

    2018-03-01

    The extraction of DNA in taeniid eggs shows complications attached to the composition of stool samples and the high resistance of eggs to degradation. The objective of this study was to test a method of DNA extraction in taeniid eggs by applying a thermal shock to facilitate the chemical-enzymatic degradation of these elements. A group of six tubes containing 1 ml of dog stool sample was spiked with eggs of Echinococcus granulosus and another group of six with Taenia pisiformis. Samples were floated with supersaturated sugar solution and centrifuged. The upper portion of each tube (500 μl) was aspirated and deposited in 1.5 ml tubes. Three tubes from each group were incubated at -20 °C and then at 90 °C, the remaining three from each group, incubated at room temperature. Proteinase K and lysis buffer were added to each tube and incubated for 12 h at 58 °C. The lysis effect was evaluated by microscopy at 3, 6 and 12 h and integrity by electrophoresis in 1% agarose gels. With the same experimental scheme, the thermal shock effect was evaluated in extractions of 1, 2, 3 and 4 eggs of each species and the DNA was quantified. Additionally, the protocol was applied in samples of 4 dogs diagnosed with natural infection by Taeniidae worms. Finally, all the extractions were tested by PCR amplification. Both E. granulosus and T. pisiformis eggs showed a similar response in the tests. In samples without treatment, the lysis effect was poor and showed no differences over time, but in those subjected to thermal shock, eggs degradation increased with time. In both treatments, there was no DNA loss integrity. The protocol applied to limited amounts of eggs yielded PCR products in 100% of the samples exposed to thermal shock, allowing PCR amplifications up to 1 egg. In non-exposed samples, the results were not replicable. However, DNA quantification showed low values in both treatments. In turn, DNA extractions with thermal shock in infected dog samples

  14. Pressure thermal shock analysis for nuclear reactor pressure vessel

    International Nuclear Information System (INIS)

    Galik, G.; Kutis, V.; Jakubec, J.; Paulech, J.; Murin, J.

    2015-01-01

    The appearance of structural weaknesses within the reactor pressure vessel or its structural failure caused by crack formation during pressure thermal shock processes pose as a severe environmental hazard. Coolant mixing during ECC cold water injection was simulated in a detailed CFD analysis. The temperature distribution acting on the pipe wall internal surface was calculated. Although, the results show the formation of high temperature differences and intense gradients, an additional structural analysis is required to determine the possibility of structural damage from PTS. Such an analysis will be the subject of follow-up research. (authors)

  15. Thermal shock experiment analysis, the use of crack arrest toughness measurements

    International Nuclear Information System (INIS)

    Miannay, D.; Pellissier-Tanon, A.; Chavaillard, J.P.

    1984-06-01

    The main purpose of thermal shock experiment is to assess the procedure codified in the ASME XI appendix 1 or RCC-M-B appendix ZG, and allow comparisons with numerical simulations. The analysis of the integrity of the PWR vessel belt line under accidental transients is based on reference curves. The test-piece is a cylinder of SA 508 cl.3 steel. Arrest toughness measured agrees with reference curve

  16. The effect of Y2O3 addition on thermal shock behavior of magnesium aluminate spinel

    Directory of Open Access Journals (Sweden)

    Pošarac Milica

    2009-01-01

    Full Text Available The effect of yttria additive on the thermal shock behavior of magnesium aluminate spinel has been investigated. As a starting material we used spinel (MgAl2O4 obtained by the modified glycine nitrate procedure (MGNP. Sintered products were characterized in terms of phase analysis, densities, thermal shock, monitoring the damaged surface area in the refractory specimen during thermal shock and ultrasonic determination of the Dynamic Young modulus of elasticity. It was found that a new phase between yttria and alumina is formed, which improved thermal shock properties of the spinel refractories. Also densification of samples is enhanced by yttria addition.

  17. Pressure vessel fracture studies pertaining to a PWR LOCA-ECC thermal shock: experiments TSE-1 and TSE-2

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1976-09-01

    The LOCA-ECC Thermal Shock Program was established to investigate the potential for flaw propagation in pressurized-water reactor (PWR) vessels during injection of emergency core coolant following a loss-of-coolant accident. Studies thus far have included fracture mechanics analyses of typical PWRs, the design and construction of a thermal shock test facility, determination of material properties for test specimens, and two thermal shock experiments with 0.53-m-OD (21-in.) by 0.15-m-wall (6-in.) cylindrical test specimens. The PWR calculations indicated that under some circumstances crack propagation could be expected and that experiments should be conducted for cracks that would have the potential for propagation at least halfway through the wall

  18. Thermal shock resistance behavior of a functionally graded ceramic: Effects of finite cooling rate

    Directory of Open Access Journals (Sweden)

    Zhihe Jin

    2014-01-01

    Full Text Available This work presents a semi-analytical model to explore the effects of cooling rate on the thermal shock resistance behavior of a functionally graded ceramic (FGC plate with a periodic array of edge cracks. The FGC is assumed to be a thermally heterogeneous material with constant elastic modulus and Poisson's ratio. The cooling rate applied at the FGC surface is modeled using a linear ramp function. An integral equation method and a closed form asymptotic temperature solution are employed to compute the thermal stress intensity factor (TSIF. The thermal shock residual strength and critical thermal shock of the FGC plate are obtained using the SIF criterion. Thermal shock simulations for an Al2O3/Si3N4 FGC indicate that a finite cooling rate leads to a significantly higher critical thermal shock than that under the sudden cooling condition. The residual strength, however, is relatively insensitive to the cooling rate.

  19. Thermal shock behaviour of mullite-bonded porous silicon carbide ceramics with yttria addition

    International Nuclear Information System (INIS)

    Ding Shuqiang; Zeng Yuping; Jiang Dongliang

    2007-01-01

    Thermal shock resistance of mullite (3Al 2 O 3 · 2SiO 2 )-bonded porous silicon carbide (SiC) ceramics with 3.0 wt% yttria (Y 2 O 3 ) addition was evaluated by a water-quenching technique. The thermal shock damage was investigated as a function of the quenching temperature, quenching cycles and specimen thickness. The residual flexural strength of the quenched specimens decreases with increasing quenching temperature and specimen thickness due to the larger thermal stress caused by thermal shock. However, quenching cycles at the temperature difference of 1200 deg. C have no effect on the residual strength since the same thermal stress was produced in repeated thermal shock processes. The good thermal shock damage resistance of the specimens is contributed mainly by the low strength and moderate elastic modulus. Moreover, the pores prevent the continuous propagation of cracks and alleviate further damage

  20. Thermal shock behavior of toughened gadolinium zirconate/YSZ double-ceramic-layered thermal barrier coating

    International Nuclear Information System (INIS)

    Zhong, Xinghua; Zhao, Huayu; Zhou, Xiaming; Liu, Chenguang; Wang, Liang; Shao, Fang; Yang, Kai; Tao, Shunyan; Ding, Chuanxian

    2014-01-01

    Highlights: • Gd 2 Zr 2 O 7 /YSZ DCL thermal barrier coating was designed and fabricated. • The Gd 2 Zr 2 O 7 top ceramic layer was toughened by addition of nanostructured 3YSZ. • Remarkable improvement in thermal shock resistance of the DCL coating was achieved. - Abstract: Double-ceramic-layered (DCL) thermal barrier coating system comprising of toughened Gadolinium zirconate (Gd 2 Zr 2 O 7 , GZ) as the top ceramic layer and 4.5 mol% Y 2 O 3 partially-stabilized ZrO 2 (4.5YSZ) as the bottom ceramic layer was fabricated by plasma spraying and thermal shock behavior of the DCL coating was investigated. The GZ top ceramic layer was toughened by addition of nanostructured 3 mol% Y 2 O 3 partially-stabilized ZrO 2 (3YSZ) to improve fracture toughness of the matrix. The thermal shock resistance of the DCL coating was enhanced significantly compared to that of single-ceramic-layered (SCL) GZ-3YSZ composite coating, which is believed to be primarily attributed to the two factors: (i) the increase in fracture toughness of the top ceramic layer by incorporating nanostructured YSZ particles and (ii) the improvement in strain tolerance through the utilization of 4.5YSZ as the bottom ceramic layer. In addition, the failure mechanisms are mainly attributed to the still low fracture toughness of the top ceramic layer and oxidation of the bond-coat

  1. Correlation of physical properties of ceramic materials with resistance to fracture by thermal shock

    Science.gov (United States)

    Lidman, W G; Bobrowsky, A R

    1949-01-01

    An analysis is made to determine which properties of materials affect their resistance to fracture by thermal stresses.From this analysis, a parameter is evaluated that is correlated with the resistance of ceramic materials to fracture by thermal shock as experimentally determined. This parameter may be used to predict qualitatively the resistance of a material to fracture by thermal shock. Resistance to fracture by thermal shock is shown to be dependent upon the following material properties: thermal conductivity, tensile strength, thermal expansion, and ductility modulus. For qualitative prediction of resistance of materials to fracture by thermal shock, the parameter may be expressed as the product of thermal conductivity and tensile strength divided by the product of linear coefficient of thermal expansion and ductility modulus of the specimen.

  2. High thermal shock resistance of the hot rolled and swaged bulk W–ZrC alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z.M.; Liu, R.; Miao, S.; Yang, X.D. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Zhang, T., E-mail: zhangtao@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Fang, Q.F.; Wang, X.P. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Liu, C.S., E-mail: csliu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Lian, Y.Y. [Southwestern Institute of Physics, Chengdu (China); Liu, X., E-mail: xliu@swip.ac.cn [Southwestern Institute of Physics, Chengdu (China); Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-15

    The thermal shock (single shot) resistance and mechanical properties of the W–0.5wt% ZrC (WZC) alloys manufactured by ordinary sintering followed by swaging or rolling process were investigated. No cracks or surface melting were detected on the surface of the rolled WZC alloy plates after thermal shock at a power density of 0.66 GW/m{sup 2} for 5 ms, while primary intergranular cracks appear on the surface of the swaged WZC samples after thermal shock at a power density of 0.44 GW/m{sup 2} for 5 ms. Three point bending tests indicate that the rolled WZC alloy has a flexural strength of ∼2.4 GPa and a total strain of 1.8% at room temperature, which are 100% and 260% higher than those of the swaged WZC, respectively. The fracture energy density of the rolled WZC alloy is 3.23 × 10{sup 7} J/m{sup 3}, about 10 times higher than that of the swaged WZC (2.9 × 10{sup 6} J/m{sup 3}). The high thermal shock resistance of the rolled WZC alloys can be ascribed to their extraordinary ductility and plasticity. - Graphical abstract: (Left panel) surface morphology observed by optical microscope after a single pulse for 5 ms with various absorbed power densities at RT on the rolled WZC. (Right panel) curves of flexural stress versus strain at RT (a) and the calculated fracture energy (b) for the swaged WZC and rolled WZC alloys. - Highlights: • No cracks or surface melting were detected on the rolled WZC alloy samples after thermal shock at 0.66 GW/m{sup 2} for 5 ms. • Hot rolled WZC alloy plates exhibit a flexural strength of 2.4 GPa and a strain of 1.8% at RT. • The fracture energy of the rolled WZC alloy is 3.23 × 10{sup 7} J/m{sup 3} at RT, about 10 times higher than that of the swaged WZC. • A detailed analysis of the relationships between the mechanical properties and the thermal shock resistance is given.

  3. National Solar Thermal Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The National Solar Thermal Test Facility (NSTTF) is the only test facility in the United States of its type. This unique facility provides experimental engineering...

  4. Apollo telescope mount thermal systems unit thermal vacuum test

    Science.gov (United States)

    Trucks, H. F.; Hueter, U.; Wise, J. H.; Bachtel, F. D.

    1971-01-01

    The Apollo Telescope Mount's thermal systems unit was utilized to conduct a full-scale thermal vacuum test to verify the thermal design and the analytical techniques used to develop the thermal mathematical models. Thermal vacuum test philosophy, test objectives configuration, test monitoring, environment simulation, vehicle test performance, and data correlation are discussed. Emphasis is placed on planning and execution of the thermal vacuum test with particular attention on problems encountered in conducting a test of this maguitude.

  5. Thermal shock studies associated with injection of emergency core coolant in pressurized water reactors

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Bolt, S.E.; Iskander, S.K.

    1977-01-01

    Studies to determine the accuracy of calculational techniques for predicting crack initiation and arrest in PWR vessels due to thermal shock from ECC injection are described. The reference calculational model is reviewed, the experimental program and facilities are described, and some thermal shock experiments and results are discussed

  6. Probabilistic structural integrity of reactor vessel under pressurized thermal shock

    International Nuclear Information System (INIS)

    Myung Jo Hhung; Young Hwan Choi; Hho Jung Kim; Changheui Jang

    2005-01-01

    Performed here is a comparative assessment study for the probabilistic fracture mechanics approach of the pressurized thermal shock of the reactor pressure vessel. A round robin consisting of 1 prerequisite study and 5 cases for probabilistic approaches is proposed, and all organizations interested are invited. The problems are solved and their results are compared to issue some recommendation of best practices in this area and to assure an understanding of the key parameters of this type of approach, which will be useful in the justification through a probabilistic approach for the case of a plant over-passing the screening criteria. Six participants from 3 organizations in Korea responded to the problem and their results are compiled in this study. (authors)

  7. Thermal shock analysis of liquid-mercury spallation target

    CERN Document Server

    Ishikura, S; Futakawa, M; Hino, R; Date, H

    2002-01-01

    The developments of the neutron scattering facilities are carried out under the high-intensity proton accelerator project promoted by JAERI and KEK. To estimate the structural integrity of the heavy liquid-metal (Hg) target used as a spallation neutron source in a MW-class neutron scattering facility, dynamic stress behavior due to the incident of a 1 MW-pulsed proton beam was analyzed by using FEM code. Two-type target containers with semi-cylindrical type and flat-plate type window were used as models for analyses. As a result, it is confirmed that the stress (pressure wave) generated by dynamic thermal shock becomes the largest at the center of window, and the flat-plate type window is more advantageous from the structural viewpoint than the semi-cylindrical type window. It has been understood that the stress generated in the window by the pressure wave can be treated as the secondary stress. (author)

  8. Thermo-hydraulic-mechanical analysis of the SS-050 sodium loop during a thermal shock of 2000C/s

    International Nuclear Information System (INIS)

    Jesus Miranda, C.A. de; Gebrin, A.N.

    1988-01-01

    An analytical thermo-hydraulic model was developed to obtain the temperature of the sodium flowing between the mixing tank TM of constant volume and the drain tank of the SS-050 sodium test facility. The piping connecting these two tanks is considered in the analysis. The sodium enters in the TM through a tube with lateral holes immersed in the TM's sodium. The model and relative computer program were tested and a typical situation was studied: a thermal shock with -200 0 C/s of thermal gradient in the test section. The sodium temperature time-histories along the piping length are presented. For the thermal shock situation, the temperature field in the TM bottom and outlet nozzle was calculated and the stresses were evaluated. The final thermal stresses will allow a detailed verification of the circuit design. (author) [pt

  9. The Sandia MEMS Passive Shock Sensor : FY08 testing for functionality, model validation, and technology readiness.

    Energy Technology Data Exchange (ETDEWEB)

    Walraven, Jeremy Allen; Blecke, Jill; Baker, Michael Sean; Clemens, Rebecca C.; Mitchell, John Anthony; Brake, Matthew Robert; Epp, David S.; Wittwer, Jonathan W.

    2008-10-01

    This report summarizes the functional, model validation, and technology readiness testing of the Sandia MEMS Passive Shock Sensor in FY08. Functional testing of a large number of revision 4 parts showed robust and consistent performance. Model validation testing helped tune the models to match data well and identified several areas for future investigation related to high frequency sensitivity and thermal effects. Finally, technology readiness testing demonstrated the integrated elements of the sensor under realistic environments.

  10. Conservatism implications of shock test tailoring for multiple design environments

    Science.gov (United States)

    Baca, Thomas J.; Bell, R. Glenn; Robbins, Susan A.

    1987-01-01

    A method for analyzing shock conservation in test specifications that have been tailored to qualify a structure for multiple design environments is discussed. Shock test conservation is qualified for shock response spectra, shock intensity spectra and ranked peak acceleration data in terms of an Index of Conservation (IOC) and an Overtest Factor (OTF). The multi-environment conservation analysis addresses the issue of both absolute and average conservation. The method is demonstrated in a case where four laboratory tests have been specified to qualify a component which must survive seven different field environments. Final judgment of the tailored test specification is shown to require an understanding of the predominant failure modes of the test item.

  11. Thermal hydraulic evaluation for an experimental facility to investigate pressurized thermal shock (PTS) in CDTN/CNEN

    International Nuclear Information System (INIS)

    Palmieri, Elcio T.; Navarro, Moyses A.; Aronne, Ivam D.; Terra, Jose L.

    2002-01-01

    The goal of the work presented in this paper is to provide necessary thermal hydraulics information to the design of an experimental installation to investigate the Pressurized Thermal Shock (PTS) to be implemented at Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN). The envisaged installation has a test section that represents, in a small scale, a pressure vessel of a nuclear reactor. This test section will be heated and then exposed to a PTS in order to evaluate the appearance and development of cracks. To verify the behavior of the temperatures of the pressure vessel after a sudden flood through the annulus, calculations were made using the RELAP5/MOD 3.2.2 gamma code. Different outer radiuses were studied for the annular region. The results showed that the smaller annulus spacing (20 mm) anticipates the wetting of the surface and produces a higher cooling of the external surface, which stays completely wet for a longer time. (author)

  12. A powerful methodology for reactor vessel pressurized thermal shock analysis

    International Nuclear Information System (INIS)

    Boucau, J.; Mager, T.

    1994-01-01

    The recent operating experience of the Pressurized Water Reactor (PWR) Industry has focused increasing attention on the issue of reactor vessel pressurized thermal shock (PTS). More specifically, the review of the old WWER-type of reactors (WWER 440/230) has indicated a sensitive behaviour to neutron embrittlement. This led already to some remedial actions including safety injection water preheating or vessel annealing. Such measures are usually taken based on the analysis of a selected number of conservative PTS events. Consideration of all postulated cooldown events would draw attention to the impact of operator action and control system effects on reactor vessel PTS. Westinghouse has developed a methodology which couples event sequence analysis with probabilistic fracture mechanics analyses, to identify those events that are of primary concern for reactor vessel integrity. Operating experience is utilized to aid in defining the appropriate event sequences and event frequencies of occurrence for the evaluation. Once the event sequences of concern are identified, detailed deterministic thermal-hydraulic and structural evaluations can be performed to determine the conditions required to minimize the extension of postulated flaws or enhance flaw arrest in the reactor vessel. The results of these analyses can then be used to better define further modifications in vessel and plant system design and to operating procedures. The purpose of the present paper will be to describe this methodology and to show its benefits for decision making. (author). 1 ref., 3 figs

  13. Integrated Software Environment for Pressurized Thermal Shock Analysis

    Directory of Open Access Journals (Sweden)

    Dino Araneo

    2011-01-01

    Full Text Available The present paper describes the main features and an application to a real Nuclear Power Plant (NPP of an Integrated Software Environment (in the following referred to as “platform” developed at University of Pisa (UNIPI to perform Pressurized Thermal Shock (PTS analysis. The platform is written in Java for the portability and it implements all the steps foreseen in the methodology developed at UNIPI for the deterministic analysis of PTS scenarios. The methodology starts with the thermal hydraulic analysis of the NPP with a system code (such as Relap5-3D and Cathare2, during a selected transient scenario. The results so obtained are then processed to provide boundary conditions for the next step, that is, a CFD calculation. Once the system pressure and the RPV wall temperature are known, the stresses inside the RPV wall can be calculated by mean a Finite Element (FE code. The last step of the methodology is the Fracture Mechanics (FM analysis, using weight functions, aimed at evaluating the stress intensity factor (KI at crack tip to be compared with the critical stress intensity factor KIc. The platform automates all these steps foreseen in the methodology once the user specifies a number of boundary conditions at the beginning of the simulation.

  14. Effect of ion implantation on thermal shock resistance of magnesia and glass

    International Nuclear Information System (INIS)

    Gurarie, V.N.; Williams, J.S.; Watt, A.J.

    1995-01-01

    Monocrystals of magnesia together with glass samples have been subjected to ion implantation prior to thermal shock testing in an impulse plasma of continuously varied intensity. Measurements of the separation between fragments have been used to estimate the surface temperature. Fracture and deformation characteristics of the surface layer are measured in ion implanted and unimplanted samples using optical and scanning electron microscopy. Implantation-induced near-surface damage is analysed by ion channeling using 2 MeV He + ions. Ion implantation is shown to modify the near-surface structure of magnesia samples by introducing damage, which makes crack initiation easier under thermal stresses. The fracture threshold and maximum crack density are shifted towards the lower temperature range. Ion implanted MgO crystals show a ten fold increase in surface crack density. An increased crack density results in a decreased degree of damage characterised by the depth of crack penetration. The thermal stress resistance parameter of glass samples is increased at relatively small doses and decreased at higher doses. The results suggest that crack density and the degree of fracture damage in brittle ceramics operating under thermal shock conditions can be effectively controlled by ion implantation which provides crack initiating defects in the near-surface region. 23 refs., 7 figs

  15. Induction of thermal shock proteins and changes in radiosensitivity after heat treatment of Bombyx mori L. embryos

    International Nuclear Information System (INIS)

    Agaev, F.A.

    1993-01-01

    The method of gel-electrophoresis was used to study thermal shock protein synthesis in Bombyx mori embryos exposed to a mixture of heat and gamma-radiation. Induction of thermal shock protein synthesis was not inhibited by gamma-radiation. It is suggested that thermal shock proteins are involved embryo radiosensitivity modification

  16. Relationship between mechanical characteristics and thermal shock stability of refractories

    International Nuclear Information System (INIS)

    Volkov-Husovic, T.; Raic, K.

    2003-01-01

    Thermal stability of the refractory material with the content of 60 % Al 2 O 3 was investigated. Water quench test (JUS.B.D8.319) was applied as experimental method for thermal stability testing. Damage of porous materials is commonly related to a modification of strength that is mostly a reduction. This is linked with characteristics related to pore space. Mechanical characteristics are considered such as compressive strength, dynamic modulus of elasticity and resistance parameters resulting from resonance frequency measurements, as well as ultrasonic velocity. (Original)

  17. Modelling of thermal shock experiments of carbon based materials in JUDITH

    International Nuclear Information System (INIS)

    Ogorodnikova, O.V.; Pestchanyi, S.; Koza, Y.; Linke, J.

    2005-01-01

    The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments

  18. Modelling of thermal shock experiments of carbon based materials in JUDITH

    Energy Technology Data Exchange (ETDEWEB)

    Ogorodnikova, O.V. [Forschungszentrum Juelich, EURATOM-Association, IWV-2, 52425 Juelich (Germany)]. E-mail: o.ogorodnikova@fz-juelich.de; Pestchanyi, S. [Forschungszentrum Karlsruhe, EURATOM-Associaton, IHM, 76021 Karlsruhe (Germany); Koza, Y. [Forschungszentrum Juelich, EURATOM-Association, IWV-2, 52425 Juelich (Germany); Linke, J. [Forschungszentrum Juelich, EURATOM-Association, IWV-2, 52425 Juelich (Germany)

    2005-03-01

    The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments.

  19. Modelling of thermal shock experiments of carbon based materials in JUDITH

    Science.gov (United States)

    Ogorodnikova, O. V.; Pestchanyi, S.; Koza, Y.; Linke, J.

    2005-03-01

    The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments.

  20. 3-D thermal weight function method and multiple virtual crack extension technique for thermal shock problems

    International Nuclear Information System (INIS)

    Lu Yanlin; Zhou Xiao; Qu Jiadi; Dou Yikang; He Yinbiao

    2005-01-01

    An efficient scheme, 3-D thermal weight function (TWF) method, and a novel numerical technique, multiple virtual crack extension (MVCE) technique, were developed for determination of histories of transient stress intensity factor (SIF) distributions along 3-D crack fronts of a body subjected to thermal shock. The TWF is a universal function, which is dependent only on the crack configuration and body geometry. TWF is independent of time during thermal shock, so the whole history of transient SIF distributions along crack fronts can be directly calculated through integration of the products of TWF and transient temperatures and temperature gradients. The repeated determinations of the distributions of stresses (or displacements) fields for individual time instants are thus avoided in the TWF method. An expression of the basic equation for the 3-D universal weight function method for Mode I in an isotropic elastic body is derived. This equation can also be derived from Bueckner-Rice's 3-D WF formulations in the framework of transformation strain. It can be understood from this equation that the so-called thermal WF is in fact coincident with the mechanical WF except for some constants of elasticity. The details and formulations of the MVCE technique are given for elliptical cracks. The MVCE technique possesses several advantages. The specially selected linearly independent VCE modes can directly be used as shape functions for the interpolation of unknown SIFs. As a result, the coefficient matrix of the final system of equations in the MVCE method is a triple-diagonal matrix and the values of the coefficients on the main diagonal are large. The system of equations has good numerical properties. The number of linearly independent VCE modes that can be introduced in a problem is unlimited. Complex situations in which the SIFs vary dramatically along crack fronts can be numerically well simulated by the MVCE technique. An integrated system of programs for solving the

  1. Thermal response of rat fibroblasts stably transfected with the human 70-kDa heat shock protein-encoding gene

    International Nuclear Information System (INIS)

    Li, G.C.; Li, Ligeng; Liu, Yunkang; Mak, J.Y.; Chen, Lili; Lee, W.M.F.

    1991-01-01

    The major heat shock protein hsp70 is synthesized by cells of a wide variety of organisms in response to heat shock or other environmental stresses and is assumed to play an important role in protecting cells from thermal stress. The authors have tested this hypothesis directly by transfecting a constitutively expressed recombinant human hsp70-encoding gene into rat fibroblasts and examining the relationship between the levels of human hsp70 expressed and thermal resistance of the stably transfected rat cells. Successful transfection and expression of the gene for human hsp70 were characterized by RNA hybridization analysis, low-dimensional gel electrophoresis, and immunoblot analysis. When individual cloned cell lines were exposed to 45C and their thermal survivals were determined by colony-formation assay, they found that the expression of human hsp70 conferred heat resistance to the rat cells. These results reinforce the hypothesis that hsp70 has a protective function against thermal stress

  2. Overview of the Integrated Pressurized Thermal-Shock (IPTS) study

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1990-01-01

    By the early 1980s, (PTS)-related, deterministic, vessel-integrity studies sponsored by the US Nuclear Regulatory Commission (NRC) indicated a potential for failure of some PWR vessels before design end of life, in the event of a postulated severe PTS transient. In response, the NRC established screening criteria, in the form of limiting values of the reference nil-ductility transition temperature (RT NDT ), and initiated the development of a probabilistic methodology for evaluating vessel integrity. This latter effort, referred to as the Integrated Pressurized Thermal-Shock (IPTS) Program, included development of techniques for postulating PTS transients, estimating their frequencies, and calculating the probability of vessel failure for a specific transient. Summing the products of frequency of transient and conditional probability of failure for each of the many postulated transients provide a calculated value of the frequency of failure. The IPTS Program also included the application of the IPTS methodology to three US PWR plants (Oconee-1, Calvert Cliffs-1, and HBRobinson-2) and the specification of a maximum permissible value of the calculated frequency of vessel failure. Another important purpose of the IPTS study was to determine, through application of the IPTS methodology, which design and operating features, parameters, and PTS transients were dominant in affecting the calculated frequency of failure. The scope of the IPTS Program included the development of a probabilistic fracture-mechanics capability, modification of the TRAC and RELAP5 thermal/hydraulic codes, and development of the methodology for estimating the uncertainty in the calculated frequency of vessel failure

  3. Hydride transport vessel vibration and shock test report

    Energy Technology Data Exchange (ETDEWEB)

    Tipton, D.G.

    1998-06-01

    Sandia National Laboratories performed vibration and shock testing on a Savannah River Hydride Transport Vessel (HTV) which is used for bulk shipments of tritium. This testing is required to qualify the HTV for transport in the H1616 shipping container. The main requirement for shipment in the H1616 is that the contents (in this case the HTV) have a tritium leak rate of less than 1x10{sup {minus}7} cc/sec after being subjected to shock and vibration normally incident to transport. Helium leak tests performed before and after the vibration and shock testing showed that the HTV remained leaktight under the specified conditions. This report documents the tests performed and the test results.

  4. Hydride transport vessel vibration and shock test report

    International Nuclear Information System (INIS)

    Tipton, D.G.

    1998-06-01

    Sandia National Laboratories performed vibration and shock testing on a Savannah River Hydride Transport Vessel (HTV) which is used for bulk shipments of tritium. This testing is required to qualify the HTV for transport in the H1616 shipping container. The main requirement for shipment in the H1616 is that the contents (in this case the HTV) have a tritium leak rate of less than 1x10 -7 cc/sec after being subjected to shock and vibration normally incident to transport. Helium leak tests performed before and after the vibration and shock testing showed that the HTV remained leaktight under the specified conditions. This report documents the tests performed and the test results

  5. PNL technical review of pressurized thermal-shock issues

    International Nuclear Information System (INIS)

    Pedersen, L.T.; Apley, W.J.; Bian, S.H.; Defferding, L.J.; Morgenstern, M.H.; Pelto, P.J.; Simonen, E.P.; Simonen, F.A.; Stevens, D.L.; Taylor, T.T.

    1982-07-01

    Pacific Northwest Laboratory (PNL) was asked to develop and recommend a regulatory position that the Nuclear Regulatory Commission (NRC) should adopt regarding the ability of reactor pressure vessels to withstand the effects of pressurized thermal shock (PTS). Licensees of eight pressurized water reactors provided NRC with estimates of remaining effective full power years before corrective actions would be required to prevent an unsafe operating condition. PNL reviewed these responses and the results of supporting research and concluded that none of the eight reactors would undergo vessel failure from a PTS event before several more years of operation. Operator actions, however, were often required to terminate a PTS event before it deteriorated to the point where failure could occur. Therefore, the near-term (less than one year) recommendation is to upgrade, on a site-specific basis, operational procedures, training, and control room instrumentation. Also, uniform criteria should be developed by NRC for use during future licensee analyses. Finally, it was recommended that NRC upgrade nondestructive inspection techniques used during vessel examinations and become more involved in the evaluation of annealing requirements

  6. Thermal shock behavior of W-ZrC/Sc2O3 composites under two different transient events by electron and laser irradiation

    Science.gov (United States)

    Chen, Hong-Yu; Luo, Lai-Ma; Zan, Xiang; Xu, Qiu; Tokunaga, Kazutoshi; Liu, Jia-Qin; Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng

    2018-02-01

    The transient thermal shock behaviors of W-ZrC/Sc2O3 composites with different ZrC contents were evaluated using transient thermal shock test by electron and laser beams. The effects of different ZrC doping contents on the surface morphology and thermal shock resistance of W-ZrC/Sc2O3 composites were then investigated. Similarity and difference between effects of electron and laser beam transient heat loading were also discussed in this study. Repeated heat loading resulted in thermal fatigue of the irradiated W-ZrC/Sc2O3 samples by thermal stress, leading to the rough surface morphologies with cracks. After different transient thermal tests, significant surface roughening, cracks, surface melting, and droplet ejection occurred. W-2vol.%Sc2O3 sample has superior thermal properties and greater resistance to surface modifications under transient thermal shock, and with the increasing ZrC content in W alloys, thermal shock resistance of W-Zr/Sc2O3 sample tends to be unsatisfied.

  7. Thermal-hydraulic analyses of pressurized-thermal-shock-induced vessel ruptures

    International Nuclear Information System (INIS)

    Dobranich, D.

    1982-05-01

    A severe overcooling transient was postulated to produce vessel wall temperatures below the nil-ductility transition temperature which in conjunction with system repressurization, led to vessel rupture at the core midplane. Such transients are referred to as pressurized-thermal-shock transients. A wide range of vessel rupture sizes were investigated to assess the emergency system's ability to cool the fuel rods. Ruptures greater than approximately 0.015 m 2 produced flows greater than those of the emergency system and resulted in core uncovery and subsequent core damage

  8. Performance of low-upper-shelf material under pressurized-thermal-shock loading (PTSE-2)

    International Nuclear Information System (INIS)

    Bryan, R.H.; Corwin, W.R.; Bass, B.R.; Nanstad, R.K.; Bolt, S.E.; Merkle, J.G.; Bryson, J.W.; Robinson, G.C.

    1988-01-01

    The second pressurized-thermal-shock experiment (Pse-2) of the Heavy-Section Steel Technology Program was conceived to investigate fracture behavior of steel with low ductile-tearing resistance. The experiment was performed in the pressurized-thermal-shock test facility at the Oak Ridge National Laboratory. PTSE-2 was designed primarily to reveal the interaction of ductile and brittle modes of fracture and secondarily to investigate the effects of warm pre-stressing. A test vessel was prepared by inserting a crack-like flaw of well-defined geometry on the outside surface of the vessel. The flaw was 1 m long by ∼ 15 mm deep. The instrumented vessel was placed in the test facility in which it ws initially heated to a uniform temperature and was then concurrently cooled on the outside and pressurized on the inside. These actions produced an evolution of temperature, toughness, and stress gradients relative to the prepared flaw that was appropriate to the planned objectives. The experiment was conducted in two separate transients, each one starting with the vessel nearly isothermal. The first transient induced a warm-prestressed state, during which K I first exceeded K Ic . This was followed by re-pressurization until a cleavage fracture propagated and arrested. The final transient was designed to produce and investigate a cleavage crack propagation followed by unstable tearing. During this transient, the fracture events occurred as had been planned. (author)

  9. Thermal Shock Resistance of Stabilized Zirconia/Metal Coat on Polymer Matrix Composites by Thermal Spraying Process

    Science.gov (United States)

    Zhu, Ling; Huang, Wenzhi; Cheng, Haifeng; Cao, Xueqiang

    2014-12-01

    Stabilized zirconia/metal coating systems were deposited on the polymer matrix composites by a combined thermal spray process. Effects of the thicknesses of metal layers and ceramic layer on thermal shock resistance of the coating systems were investigated. According to the results of thermal shock lifetime, the coating system consisting of 20 μm Zn and 125 μm 8YSZ exhibited the best thermal shock resistance. Based on microstructure evolution, failure modes and failure mechanism of the coating systems were proposed. The main failure modes were the formation of vertical cracks and delamination in the outlayer of substrate, and the appearance of coating spallation. The residual stress, thermal stress and oxidation of substrate near the substrate/metal layer interface were responsible for coating failure, while the oxidation of substrate near the substrate/coating interface was the dominant one.

  10. Finite element study of a HDR-RPV-section including a nozzle under thermal shock transient

    Energy Technology Data Exchange (ETDEWEB)

    Roos, E [Stuttgart Univ. (Germany); Katzenmeier, G [Forschungszentrum Juelich GmbH (Germany); Wanner, R; Mercier, O [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1988-12-31

    This document presents a finite element study of a reactor pressure vessel section under thermal stresses. The strength properties of the vessel walls are studied as well as cracks due to the thermo-shock transient. (TEC). 6 refs.

  11. On-line monitoring on thermal shock damage of ceramics using acoustic emission

    International Nuclear Information System (INIS)

    Lee, Jin Kyung; Lee, Joon Hyun; Song, Sang Hun

    1999-01-01

    The objective of this paper is to investigate the degree of the thermal shock damage on alumina ceramic using acoustic emission technique. For this purpose, alumina ceramic specimen was heated in the elastic furnace and then was quenched into the water tank. When the specimen was quenched into water tank, a lot of micro-cracks were generated on the surface of specimen due to the thermal shock damage. In this study, acoustic emission technique was used to evaluate the elastic waves generated by the crack initiation and propagation on the surface of specimen. It was found that when the micro-crack was initiated on the surface of specimen, AE signals were the higher in amplitude than those of bubbling effect and crack propagation. A lot of AE events were generated at the first thermal shock, the number of AE events decreased gradually as the thermal shock cycle increased.

  12. Thermal shock behaviour of H and H/He-exposed tungsten at high temperature

    International Nuclear Information System (INIS)

    Lemahieu, N; Linke, J; Pintsuk, G; Wirtz, M; Greuner, H; Maier, H; Oost, G Van; Noterdaeme, J-M

    2016-01-01

    Polycrystalline tungsten samples were characterized and exposed to a pure H beam or mixed H/He beam containing 6% He in GLADIS at a surface temperature of 600 °C, 1000 °C, or 1500 °C. After 5400 s of exposure time with a heat flux of 10.5 MW m −2 , the total accumulated fluence of 2 × 10 25 m −2 was reached. Thereafter, edge localized mode (ELM)-like thermal shocks with a duration of 1 ms and an absorbed power density of 190 MW m −2 and 380 MW m −2 were applied on the samples in JUDITH 1. During the thermal shocks, the base temperature was kept at 1000 °C. The ELM-experiments with the lowest transient power density did not result in any detected damage. The other tests showed the beginning of crack formation for every sample, except the sample pre-exposed with the pure H-beam at 1500 °C in GLADIS. This sample was roughened, but did not show any crack initiation. With exception to the roughened sample, the category of ELM-induced damage for the pre-exposed samples is identical to the reference tests without pre-exposure to a particle flux. (paper)

  13. VISA-2, Reactor Vessel Failure Probability Under Thermal Shock

    International Nuclear Information System (INIS)

    Simonen, F.; Johnson, K.

    1992-01-01

    1 - Description of program or function: VISA2 (Vessel Integrity Simulation Analysis) was developed to estimate the failure probability of nuclear reactor pressure vessels under pressurized thermal shock conditions. The deterministic portion of the code performs heat transfer, stress, and fracture mechanics calculations for a vessel subjected to a user-specified temperature and pressure transient. The probabilistic analysis performs a Monte Carlo simulation to estimate the probability of vessel failure. Parameters such as initial crack size and position, copper and nickel content, fluence, and the fracture toughness values for crack initiation and arrest are treated as random variables. Linear elastic fracture mechanics methods are used to model crack initiation and growth. This includes cladding effects in the heat transfer, stress, and fracture mechanics calculations. The simulation procedure treats an entire vessel and recognizes that more than one flaw can exist in a given vessel. The flaw model allows random positioning of the flaw within the vessel wall thickness, and the user can specify either flaw length or length-to-depth aspect ratio for crack initiation and arrest predictions. The flaw size distribution can be adjust on the basis of different inservice inspection techniques and inspection conditions. The toughness simulation model includes a menu of alternative equations for predicting the shift in the reference temperature of the nil-ductility transition. 2 - Method of solution: The solution method uses closed form equations for temperatures, stresses, and stress intensity factors. A polynomial fitting procedure approximates the specified pressure and temperature transient. Failure probabilities are calculated by a Monte Carlo simulation. 3 - Restrictions on the complexity of the problem: Maxima of 30 welds. VISA2 models only the belt-line (cylindrical) region of a reactor vessel. The stresses are a function of the radial (through-wall) coordinate only

  14. Oxidation and thermal shock behavior of thermal barrier coated 18/10CrNi alloy with coating modifications

    Energy Technology Data Exchange (ETDEWEB)

    Guergen, Selim [Vocational School of Transportation, Anadolu University, Eskisehir (Turkmenistan); Diltemiz, Seyid Fehmi [Turkish Air Force1st Air Supply and Maintenance Center Command, Eskisehir (Turkmenistan); Kushan, Melih Cemal [Dept. of Mechanical Engineering, Eskisehir Osmangazi University, Eskisehir (Turkmenistan)

    2017-01-15

    In this study, substrates of 18/10CrNi alloy plates were initially sprayed with a Ni-21Cr-10Al-1Y bond coat and then with an yttria stabilized zirconia top coat by plasma spraying. Subsequently, plasma-sprayed Thermal barrier coatings (TBCs) were treated with two different modification methods, namely, vacuum heat treatment and laser glazing. The effects of modifications on the oxidation and thermal shock behavior of the coatings were evaluated. The effect of coat thickness on the bond strength of the coats was also investigated. Results showed enhancement of the oxidation resistance and thermal shock resistance of TBCs following modifications. Although vacuum heat treatment and laser glazing exhibited comparable results as per oxidation resistance, the former generated the best improvement in the thermal shock resistance of the TBCs. Bond strength also decreased as coat thickness increased.

  15. Electron bulk acceleration and thermalization at Earth's quasi-perpendicular bow shock

    Science.gov (United States)

    Chen, L.-J.; Wang, S.; Wilson, L. B., III; Schwartz, S. J.; Bessho, N.; Moore, T. E.; Gershman, D. J.; Giles, B. L.; Malaspina, D. M.; Wilder, F. D.; Ergun, R. E.; Hesse, M.; Lai, H.; Russell, C. T.; Strangeway, R. J.; Torbert, R. B.; Vinas, A. F.-; Burch, J. L.; Lee, S.; Pollock, C.; Dorelli, J.; Paterson, W. R.; Ahmadi, N.; Goodrich, K. A.; Lavraud, B.; Le Contel, O.; Khotyaintsev, Yu. V.; Lindqvist, P.-A.; Boardsen, S.; Wei, H.; Le, A.; Avanov, L. A.

    2018-05-01

    Electron heating at Earth's quasiperpendicular bow shock has been surmised to be due to the combined effects of a quasistatic electric potential and scattering through wave-particle interaction. Here we report the observation of electron distribution functions indicating a new electron heating process occurring at the leading edge of the shock front. Incident solar wind electrons are accelerated parallel to the magnetic field toward downstream, reaching an electron-ion relative drift speed exceeding the electron thermal speed. The bulk acceleration is associated with an electric field pulse embedded in a whistler-mode wave. The high electron-ion relative drift is relaxed primarily through a nonlinear current-driven instability. The relaxed distributions contain a beam traveling toward the shock as a remnant of the accelerated electrons. Similar distribution functions prevail throughout the shock transition layer, suggesting that the observed acceleration and thermalization is essential to the cross-shock electron heating.

  16. Computational methods for fracture mechanics analysis of pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    Bass, B.R.; Bryan, R.H.; Bryson, J.W.; Merkle, J.G.

    1984-01-01

    Extensive computational analyses are required to determine material parameters and optimum pressure-temperature transients compatible with proposed pressurized-thermal-shock (PTS) test scenarios and with the capabilities of the PTS test facility at the Oak Ridge National Laboratory (ORNL). Computational economy has led to the application of techniques suitable for parametric studies involving the analysis of a large number of transients. These techniques, which include analysis capability for two- and three-dimensional (2-D and 3-D) superposition, inelastic ligament stability, and upper-shelf arrest, have been incorporated into the OCA/USA computer program. Features of the OCA/USA program are discussed, including applications to the PTS test configuration

  17. Computational methods for fracture mechanics analysis of pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    Bass, B.R.; Bryan, R.H.; Bryson, J.W.; Merkle, J.G.

    1984-01-01

    Extensive computational analyses are required to determine material parameters and optimum pressure-temperature transients compatible with proposed pressurized-thermal-shock (PTS) test scenarios and with the capabilities of the PTS test facility at the Oak Ridge National Laboratory (ORNL). Computational economy has led to the application of techniques suitable for parametric studies involving the analysis of a large number of transients. These techniques, which include analysis capability for two- and three-dimensional (2-D and 3-D) superposition, inelastic ligament stability, and upper-shelf arrest, have been incorporated into the OCA/ USA computer program. Features of the OCA/USA program are discussed, including applications to the PTS test configuration. (author)

  18. Mechanical Properties and Thermal Shock Resistance Analysis of BNNT/Si3N4 Composites

    Science.gov (United States)

    Wang, Shouren; Wang, Gaoqi; Wen, Daosheng; Yang, Xuefeng; Yang, Liying; Guo, Peiquan

    2018-04-01

    BNNT/Si3N4 ceramic composites with different weight amount of BNNT fabricated by hot isostatic pressing were introduced. The mechanical properties and thermal shock resistance of the composites were investigated. The results showed that BNNT-added ceramic composites have a finer and more uniform microstructure than that of BNNT-free Si3N4 ceramic because of the retarding effect of BNNT on Si3N4 grain growth. The addition of 1.5 wt.% BNNT results in simultaneous increase in flexural strength, fracture toughness, and thermal shock resistance. The analysis of the results indicates that BNNT brings many thermal transport channels in the microstructure, increasing the efficiency of thermal transport, therefore results in increase of thermal shock resistance. In addition, BNNT improves the residual flexural strength of composites by crack deflection, bridging, branching and pinning, which increase the crack propagation resistance.

  19. The Shock and Vibration Bulletin. Part 1. Opening Session, Panel Session, Shock Analysis Shock Testing, Isolation and Damping.

    Science.gov (United States)

    1977-09-01

    ORTHOTROPIC PLATES WITH VARIOUS ,I PLANFORMS AND EDGE CONDITIONS C.W. Bert, The University of Oklahoma, Norman , OK - -’ DYNAMIC RESPONSE OF LAMINATED...EVALUATION OF AN ADAPTIVE FILTER AS A DIGITAL TRACKING FILTER D.O. Smallwood and D.L. Gregory, Sandia Laboratories, Albuquerque, NM TOTAL MISSION ENVIRONMENTAL...June 1967. ration Bulletin No. 40, Part 2, 1969. 6. J. P. Barthmaier, "Shock Testing Under 2. D. 0. Smallwood , "Time History Synthesis Minicomputer

  20. Open stack thermal battery tests

    Energy Technology Data Exchange (ETDEWEB)

    Long, Kevin N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grillet, Anne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Headley, Alexander J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fenton, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wong, Dennis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingersoll, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-04-17

    We present selected results from a series of Open Stack thermal battery tests performed in FY14 and FY15 and discuss our findings. These tests were meant to provide validation data for the comprehensive thermal battery simulation tools currently under development in Sierra/Aria under known conditions compared with as-manufactured batteries. We are able to satisfy this original objective in the present study for some test conditions. Measurements from each test include: nominal stack pressure (axial stress) vs. time in the cold state and during battery ignition, battery voltage vs. time against a prescribed current draw with periodic pulses, and images transverse to the battery axis from which cell displacements are computed. Six battery configurations were evaluated: 3, 5, and 10 cell stacks sandwiched between 4 layers of the materials used for axial thermal insulation, either Fiberfrax Board or MinK. In addition to the results from 3, 5, and 10 cell stacks with either in-line Fiberfrax Board or MinK insulation, a series of cell-free “control” tests were performed that show the inherent settling and stress relaxation based on the interaction between the insulation and heat pellets alone.

  1. H/He irradiation on tungsten exposed to ELM-like thermal shocks

    International Nuclear Information System (INIS)

    Lemahieu, Nathan; Balden, Martin; Elgeti, Stefan; Greuner, Henri; Linke, Jochen; Maier, Hans; Pintsuk, Gerald; Wirtz, Marius; Van Oost, Guido; Noterdaeme, Jean-Marie

    2016-01-01

    Highlights: • After ELM-like thermal shocks, tungsten was exposed to H/He particle fluxes. • The influence of combined loading conditions on the damage behaviour was studied. • Roughened surfaces do not alter H/He induced surface modifications. • Cracks interact with the particle flux, resulting in phenomena such as crack bridging. - Abstract: ELM-like thermal shocks and H/He particle exposure were subsequently applied on tungsten samples. Polished test specimens underwent in the JUDITH 1 electron beam facility 100 transient thermal events with a duration of 1 ms. The absorbed heat flux was 0.4 GW m"−"2 and 1.5 GW m"−"2, which is above the material's damage threshold. These experiments were done at room temperature and with the samples heated to 400 °C base temperature. Depending on the loading conditions the test specimens have either a crack network or showed surface roughening. The samples were then loaded in the GLADIS facility at different surface temperatures with a mixed H/He beam with a flux of 3.7 × 10"2"1 m"−"2 s"−"1. Post-mortem analysis showed that the roughened surface did not alter the H/He induced surface modifications. In contrast to that on the test specimens that exhibited crack formation, phenomena such as bubble creation along the crack edge, formation of a shallow layer of nano-structures covering the crack opening, and the emerging of a porous structure which partially fills the crack are observed.

  2. H/He irradiation on tungsten exposed to ELM-like thermal shocks

    Energy Technology Data Exchange (ETDEWEB)

    Lemahieu, Nathan, E-mail: Nathan.Lemahieu@UGent.be [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Institute of Interfacial Process Engineering and Plasma Technology IGVP, Universität Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany); Balden, Martin; Elgeti, Stefan; Greuner, Henri [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Linke, Jochen [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Maier, Hans [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Pintsuk, Gerald; Wirtz, Marius [Institute for Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich (Germany); Van Oost, Guido [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Noterdaeme, Jean-Marie [Max Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching (Germany); Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium)

    2016-11-01

    Highlights: • After ELM-like thermal shocks, tungsten was exposed to H/He particle fluxes. • The influence of combined loading conditions on the damage behaviour was studied. • Roughened surfaces do not alter H/He induced surface modifications. • Cracks interact with the particle flux, resulting in phenomena such as crack bridging. - Abstract: ELM-like thermal shocks and H/He particle exposure were subsequently applied on tungsten samples. Polished test specimens underwent in the JUDITH 1 electron beam facility 100 transient thermal events with a duration of 1 ms. The absorbed heat flux was 0.4 GW m{sup −2} and 1.5 GW m{sup −2}, which is above the material's damage threshold. These experiments were done at room temperature and with the samples heated to 400 °C base temperature. Depending on the loading conditions the test specimens have either a crack network or showed surface roughening. The samples were then loaded in the GLADIS facility at different surface temperatures with a mixed H/He beam with a flux of 3.7 × 10{sup 21} m{sup −2} s{sup −1}. Post-mortem analysis showed that the roughened surface did not alter the H/He induced surface modifications. In contrast to that on the test specimens that exhibited crack formation, phenomena such as bubble creation along the crack edge, formation of a shallow layer of nano-structures covering the crack opening, and the emerging of a porous structure which partially fills the crack are observed.

  3. An investigation into the relationship between thermal shock resistance and ballistic performance of ceramic materials

    Science.gov (United States)

    Beaumont, Robert

    Currently, there are no reliable methods for screening potential armour materials and hence full-scale ballistic trials are needed. These are both costly and time-consuming in terms of the actual test and also in the materials development that needs to take place to produce sufficient material to give a meaningful result. Whilst it will not be possible to dispense with ballistic trials before material deployment in armour applications, the ability to shorten the development cycle would be advantageous. The thermal shock performance of ceramic armour materials has been highlighted as potential marker for ballistic performance. Hence the purpose of this study was to investigate this further. A new thermal shock technique that reproduced features relevant to ballistic testing was sought. As it would be beneficial to have a simple test that did not use much material, a water-drop method was adopted. This was combined with a variety of characterisation techniques, administered pre- and post-shock. The methods included measurement of the amplitude of ultrasonic wave transmission through the sample alongside residual strength testing using a biaxial ball-on-ball configuration and reflected light and confocal microscopy. Once the protocols had been refined the testing regime was applied to a group of ceramic materials. The materials selected were from two broad groups: alumina and carbide materials. Carbide ceramics show superior performance to alumina ceramics in ballistic applications so it was essential that any screening test would be easily able to differentiate the two groups. Within the alumina family, two commercially available materials, AD995 and Sintox FA, were selected. These were tested alongside three developmental silicon carbide-boron carbide composites, which had identical chemical compositions but different microstructures and thus presented more of a challenge in terms of differentiation. The results from the various tests were used to make predictions

  4. Impact of the surface quality on the thermal shock performance of beryllium armor tiles for first wall applications

    Energy Technology Data Exchange (ETDEWEB)

    Spilker, B., E-mail: b.spilker@fz-juelich.de; Linke, J.; Pintsuk, G.; Wirtz, M.

    2016-11-01

    Highlights: • Different surface qualities of S-65 beryllium are tested under high heat flux conditions. • After 1000 thermal shocks, the loaded area exhibits a crucial destruction. • Stress accelerated grain boundary oxidation/dynamic embrittlement effects are linked to the thermal shock performance of beryllium. • Thermally induced cracks form between 1 and 10 pulses and grow wider and deeper between 10 and 100 pulses. • Thermally induced cracks form and propagate independently from surface grooves and the surface quality. - Abstract: Beryllium will be applied as first wall armor material in ITER. The armor has to sustain high steady state and transient power fluxes. For transient events like edge localized modes, these transient power fluxes rise up to 1.0 GW m{sup −2} with a duration of 0.5–0.75 ms in the divertor region and a significant fraction of this power flux is deposited on the first wall as well. In the present work, the reference beryllium grade for the ITER first wall application S-65 was prepared with various surface conditions and subjected to transient power fluxes (thermal shocks) with ITER relevant loading parameters. After 1000 thermal shocks, a crucial destruction of the entire loaded area was observed and linked to the stress accelerated grain boundary oxidation (SAGBO)/dynamic embrittlement (DE) effect. Furthermore, the study revealed that the majority of the thermally induced cracks formed between 1 and 10 pulses and then grew wider and deeper with increasing pulse number. The surface quality did not influence the cracking behavior of beryllium in any detectable way. However, the polished surface demonstrated the highest resistance against the observed crucial destruction mechanism.

  5. Pressurized-thermal-shock experiments: PTSE-1 results and PTSE-2 plans

    International Nuclear Information System (INIS)

    Bryan, R.H.; Nanstad, R.K.; Wanner, R.; Merkle, J.G.; Robinson, G.C.; Whitman, G.D.

    1985-01-01

    The first pressurized-thermal-shock experiment (PTSE-1) was performed with a vessel with a 1-m-long flaw in a plug of specially tempered steel having the composition of SA-508 forging steel. The second experiment (PTSE-2) will have a similar arrangement, but the material in which the flaw will be implanted is being prepared to have low tearing resistance. Special tempering of a 2 1/4 Cr - 1 Mo steel plate has been shown to induce a low Charpy impact energy in the upper-shelf temperature range. The purpose of PTSE-2 is to investigate the fracture behavior of low-upper-shelf material in a vessel under the combined loading of concurrent pressure and thermal shock. The primary objective of the experimental plan is to induce a rapidly propagating cleavage fracture under conditions that are likely to induce a ductile tearing instability at the time of arrest of the cleavage fracture. The secondary objective of the test is to extend the range of the investigation of warm prestressing. 11 figs

  6. Solar-Thermal Engine Testing

    Science.gov (United States)

    Tucker, Stephen; Salvail, Pat; Haynes, Davy (Technical Monitor)

    2001-01-01

    A solar-thermal engine serves as a high-temperature solar-radiation absorber, heat exchanger, and rocket nozzle. collecting concentrated solar radiation into an absorber cavity and transferring this energy to a propellant as heat. Propellant gas can be heated to temperatures approaching 4,500 F and expanded in a rocket nozzle, creating low thrust with a high specific impulse (I(sub sp)). The Shooting Star Experiment (SSE) solar-thermal engine is made of 100 percent chemical vapor deposited (CVD) rhenium. The engine 'module' consists of an engine assembly, propellant feedline, engine support structure, thermal insulation, and instrumentation. Engine thermal performance tests consist of a series of high-temperature thermal cycles intended to characterize the propulsive performance of the engines and the thermal effectiveness of the engine support structure and insulation system. A silicone-carbide electrical resistance heater, placed inside the inner shell, substitutes for solar radiation and heats the engine. Although the preferred propellant is hydrogen, the propellant used in these tests is gaseous nitrogen. Because rhenium oxidizes at elevated temperatures, the tests are performed in a vacuum chamber. Test data will include transient and steady state temperatures on selected engine surfaces, propellant pressures and flow rates, and engine thrust levels. The engine propellant-feed system is designed to Supply GN2 to the engine at a constant inlet pressure of 60 psia, producing a near-constant thrust of 1.0 lb. Gaseous hydrogen will be used in subsequent tests. The propellant flow rate decreases with increasing propellant temperature, while maintaining constant thrust, increasing engine I(sub sp). In conjunction with analytical models of the heat exchanger, the temperature data will provide insight into the effectiveness of the insulation system, the structural support system, and the overall engine performance. These tests also provide experience on operational

  7. Improvement of thermal shock resistance of isotropic graphite by ti-doping

    International Nuclear Information System (INIS)

    Lopez-Galilea, I.; Ordas, N.; Garcia-Rosales, C.; Lindig, S.

    2007-01-01

    order to establish a relationship between the catalytic effect of TiC and the final properties (density, porosity, mechanical properties, thermal conductivity, thermal shock resistance...). The study of microstructural evolution and carbide distribution during the heat treatments is presented. In addition, the evaluation of the fracture surfaces after bending tests allows understanding the reinforcement effect of TiC. (authors)

  8. Improvement of thermal shock resistance of isotropic graphite by ti-doping

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Galilea, I.; Ordas, N.; Garcia-Rosales, C. [Navarrra Univ., CEPT, San Sebastian (Spain); Lindig, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Garching (Germany)

    2007-07-01

    order to establish a relationship between the catalytic effect of TiC and the final properties (density, porosity, mechanical properties, thermal conductivity, thermal shock resistance...). The study of microstructural evolution and carbide distribution during the heat treatments is presented. In addition, the evaluation of the fracture surfaces after bending tests allows understanding the reinforcement effect of TiC. (authors)

  9. Application of large-eddy simulation to pressurized thermal shock: Assessment of the accuracy

    International Nuclear Information System (INIS)

    Loginov, M.S.; Komen, E.M.J.; Hoehne, T.

    2011-01-01

    Highlights: → We compare large-eddy simulation with experiment on the single-phase pressurized thermal shock problem. → Three test cases are considered, they cover entire range of mixing patterns. → The accuracy of the flow mixing in the reactor pressure vessel is assessed qualitatively and quantitatively. - Abstract: Pressurized Thermal Shock (PTS) is identified as one of the safety issues where Computational Fluid Dynamics (CFD) can bring real benefits. The turbulence modeling may impact overall accuracy of the calculated thermal loads on the vessel walls, therefore advanced methods for turbulent flows are required. The feasibility and mesh resolution of LES for single-phase PTS are assessed earlier in a companion paper. The current investigation deals with the accuracy of LES approach with respect to the experiment. Experimental data from the Rossendorf Coolant Mixing (ROCOM) facility is used as a basis for validation. Three test cases with different flow rates are considered. They correspond to a buoyancy-driven, a momentum-driven, and a transitional coolant mixing pattern in the downcomer. Time- and frequency-domain analysis are employed for comparison of the numerical and experimental data. The investigation shows a good qualitative prediction of the bulk flow patterns. The fluctuations are modeled correctly. A conservative estimate of the temperature drop near the wall can be obtained from the numerical results with safety factor of 1.1-1.3. In general, the current LES gives a realistic and reliable description of the considered coolant mixing experiments. The accuracy of the prediction is definitely improved with respect to earlier CFD simulations.

  10. FABRICATION OF MICROPOROUS SILICA CERAMICS WITH VARIED POLYMORPHIC FORMS AND INVESTIGATION OF THEIR THERMAL SHOCK BEHAVIOUR

    Directory of Open Access Journals (Sweden)

    Osman ŞAN

    2011-06-01

    Full Text Available In this study; the SiO₂ micro-porous ceramics in the phase α-quartz, α-cristobalite and β-cristobalite were produced and thermal shock resistance of products were compared. In the production of ceramic materials; α-quartz obtained from natural quartz powder, α-cristobalite from pure silica powder which prepared by Stöber technique and β-cristobalite from sol-gel approach. The β-composition was designed as Si₁₋⨯Al⨯Ca⨯/₂O₂ where x=0.05 and obtained gel was calcined at 850 °C. Before shaping, α-quartz powder and calcined β-cristobalite powder were grind in the planetary mill and the powder produced by Stöber technique was shaped directly without any milling process. The prepared powders were shaped by uniaxally press at 50 bars. The samples produced from α-quartz and β-cristobalite powders were sintered at 1150 °C and α-cristobalite obtained by Stöber technique was sintered at 1400 °C. In the defined polymorphic structure, micro-porous materials with pore size ~0.1-5 µm were produced and thermal shock tests were applied. Irrespective of β-cristobalite material, the samples were cracked and the tests could only repeat on the samples with β-cristobalite material. In the result, the β-cristobalite sample is believed to be great potential to use as a membrane filters for harsh thermal environments.

  11. Predictive FEM simulation of thermal shock damage in the refractory lining of steelmaking installations

    NARCIS (Netherlands)

    Damhof, F.; Brekelmans, W.A.M.; Geers, M.G.D.

    2011-01-01

    Thermal shock damage in the refractory lining of steelmaking installations is modelled using an experimentally validated constitutive damage framework which is coupled incrementally with a thermo-elastic FE package. Both non-local elasticity-based damage induced by temperature gradients and thermal

  12. Non-local modelling of cyclic thermal shock damage including parameter estimation

    NARCIS (Netherlands)

    Damhof, F.; Brekelmans, W.A.M.; Geers, M.G.D.

    2011-01-01

    In this paper, rate dependent evolution laws are identified and characterized to model the mechanical (elasticity-based) and thermal damage occurring in coarse grain refractory material subject to cyclic thermal shock. The interacting mechanisms for elastic deformation driven damage induced by

  13. 16 CFR 1204.4 - Electric shock protection tests.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Electric shock protection tests. 1204.4 Section 1204.4 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... the cable shall be between 28 and 29 feet (8.5 to 8.8 meters) above a horizontal plane through the...

  14. Cadmium safety rod thermal tests

    International Nuclear Information System (INIS)

    Thomas, J.K.; Iyer, N.C.; Peacock, H.B.

    1992-01-01

    Thermal testing of cadmium safety rods was conducted as part of a program to define the response of Savannah River Site (SRS) production reactor core components to a hypothetical LOCA leading to a drained reactor tank. The safety rods are present in the reactor core only during shutdown and are not used as a control mechanism during operation; thus, their response to the conditions predicted for the LOCA is only of interest to the extent that it could impact the progression of the accident. This document provides a description of this testing

  15. Thermal shock behavior of nano-sized SiC particulate reinforced AlON composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, X.J. [Department of Materials Science and Engineering, School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004 (China); Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Ru, H.Q., E-mail: ruhq@smm.neu.edu.cn [Department of Materials Science and Engineering, School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004 (China); Chen, D.L., E-mail: dchen@ryerson.ca [Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Zhang, N.; Liang, B. [Key Laboratory of Advanced Materials Manufacturing Technology of Liaoning Province, Shenyang University, Shenyang, Liaoning 110044 (China)

    2012-03-25

    Highlights: Black-Right-Pointing-Pointer Addition of nano-SiC particles enhances residual strength and critical temperature. Black-Right-Pointing-Pointer Young's modulus decreases with increasing quenching temperature. Black-Right-Pointing-Pointer Linear relationship between residual strength and thermal shock times is obtained. Black-Right-Pointing-Pointer Rougher fracture surfaces in the SiC-AlON composites are observed. - Abstract: Aluminum oxynitride (AlON) has been considered as a potential ceramic material for high-performance structural and advanced refractory applications. Thermal shock resistance is a major concern and an important performance index of high-temperature ceramics. While silicon carbide (SiC) particles have been proven to improve mechanical properties of AlON ceramic, the high-temperature thermal shock behavior was unknown. The aim of this investigation was to identify the thermal shock resistance and underlying mechanisms of AlON ceramic and 8 wt% SiC-AlON composites over a temperature range between 175 Degree-Sign C and 275 Degree-Sign C. The residual strength and Young's modulus after thermal shock decreased with increasing quenching temperature and thermal shock times due to large temperature gradients and thermal stresses caused by abrupt water-quenching. A linear relationship between the residual strength and thermal shock times was observed in both pure AlON and SiC-AlON composites. The addition of nano-sized SiC particles increased both residual strength and critical temperature from 200 Degree-Sign C in the monolithic AlON to 225 Degree-Sign C in the SiC-AlON composites due to the toughening effect, the lower coefficient of thermal expansion and higher thermal conductivity of SiC. The enhancement of the thermal shock resistance in the SiC-AlON composites was directly related to the change of fracture mode from intergranular cracking along with cleavage-type fracture in the AlON to a rougher fracture surface with ridge

  16. Molecular dynamics of shock waves in one-dimensional chains. II. Thermalization

    International Nuclear Information System (INIS)

    Straub, G.K.; Holian, B.L.; Petschek, R.G.

    1979-01-01

    The thermalization behavior behind a shock front in one-dimensional chains has been studied in a series of molecular-dynamics computer experiments. We have found that a shock wave generated in a chain initially at finite temperature has essentially the same characteristics as in a chain initially at zero temperature. We also find that the final velocity distribution function for particles behind the shock front is not the Maxwell-Boltzmann distribution for an equilibrium system of classical particles. For times long after the shock has passed, we propose a nonequilibrium velocity distribution which is based upon behavior in the harmonic and hard-rod limits and agrees with our numerical results. Temperature profiles for both harmonic and anharmonic chains are found to exhibit a long-time tail that decays inversely with time. Finally, we have run a computer experiment to generate what qualitatively resembles solitons in Toda chains by means of shock waves

  17. Pressure vessel fracture studies pertaining to a PWR LOCA-ECC thermal shock: experiments TSE-3 and TSE-4 and update of TSE-1 and TSE-2 analysis

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Bolt, S.E.

    1977-01-01

    The LOCA-ECC Thermal Shock Program was established to investigate the potential for flaw propagation in pressurized-water reactor (PWR) vessels during injection of emergency core coolant following a loss-of-coolant accident. Studies thus far have included fracture mechanics analyses of typical PWRs, the design and construction of a thermal shock test facility, determination of material properties for test specimens, and four thermal shock experiments with 0.53-m-OD (21-in.) by 0.15-m-wall (6-in.) cylindrical test specimens. In the first experiment, initiation was not expected and did not occur, although there was a small amount of subcritical crack growth. In the second experiment, initiation of a semicircular flaw took place as expected; the final length along the surface was about four times the initial length, but there was no radial growth. The third and fourth experiments were similar, and the long axial flaw initiated in good agreement with predictions

  18. An integrity evaluation method of the pressure vessel of nuclear reactors under pressurized thermal shock

    International Nuclear Information System (INIS)

    Matsubara, Masaaki; Okamura, Hiroyuki.

    1987-01-01

    Present paper proposes a new algorithm of the integrity evaluation of the pressure vessel of nuclear reactors under pressurized thermal shock, PTS. This method enables us to do an effective evaluation by superimposing proposed ''PTS state-transient curves'' and ''toughness transient curves'', and is superior to a conventional one in the following points; (1) easy to get an overall view of the result of PTS event for the variations of several parameters, (2) possible to evaluate a safety margin for irradiation embrittlement, and (3) enable to construct an Expert-friendly evaluation system. In addition, the paper shows that we can execute a safety assurance test by using a flat plate model with the same thickness as that of real plant. (author)

  19. Effects caused by thermal shocks in plasma sprayed protective coatings from materials based on Al2O3

    International Nuclear Information System (INIS)

    Gorski, L.; Wolski, T.; Gostynski, D.

    1996-01-01

    Plasma sprayed coatings from the materials based on Al 2 O 3 with addition of NiO and TiO 2 have been studied. Thermal shock resistance of these coatings has been tested on special experimental arrangement in the stream of hot and cold gases. Changes in coating microstructure has been determined by light microscopy methods. Phase transition caused by the experiments are revealed by X-ray diffraction methods. The resistance for thermal fatigue processes depends on used coatings materials. (author). 21 refs, 21 figs, 1 tab

  20. Simulation and Analysis of Converging Shock Wave Test Problems

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory

    2012-06-21

    Results and analysis pertaining to the simulation of the Guderley converging shock wave test problem (and associated code verification hydrodynamics test problems involving converging shock waves) in the LANL ASC radiation-hydrodynamics code xRAGE are presented. One-dimensional (1D) spherical and two-dimensional (2D) axi-symmetric geometric setups are utilized and evaluated in this study, as is an instantiation of the xRAGE adaptive mesh refinement capability. For the 2D simulations, a 'Surrogate Guderley' test problem is developed and used to obviate subtleties inherent to the true Guderley solution's initialization on a square grid, while still maintaining a high degree of fidelity to the original problem, and minimally straining the general credibility of associated analysis and conclusions.

  1. Preliminary applications of the new Neptune two-phase CFD solver to pressurized thermal shock investigations

    International Nuclear Information System (INIS)

    Boucker, M.; Laviaville, J.; Martin, A.; Bechaud, C.; Bestion, D.; Coste, P.

    2004-01-01

    The objective of this communication is to present some preliminary applications to pressurized thermal shock (PTS) investigations of the CFD (Computational Fluid Dynamics) two-phase flow solver of the new NEPTUNE thermal-hydraulics platform. In the framework of plant life extension, the Reactor Pressure Vessel (RPV) integrity is a major concern, and an important part of RPV integrity assessment is related to PTS analysis. In the case where the cold legs are partially filled with steam, it becomes a two-phase problem and new important effects occur, such as condensation due to the Emergency Core Cooling (ECC) injections of sub-cooled water. Thus, an advanced prediction of RPV thermal loading during these transients requires sophisticated two-phase, local scale, 3-dimensional codes. In that purpose, a program has been set up to extend the capabilities of the NEPTUNE two-phase CFD solver. A simple set of turbulence and condensation model for free surface steam-water flow has been tested in simulation of an ECC high pressure injection representing facility, using a full 3-dimensional mesh and the new NEPTUNE solver. Encouraging results have been obtained but it should be noticed that several sources of error can compensate for one another. Nevertheless, the computation presented here allows to be reasonable confident in the use of two-phase CFD in order to carry out refined analysis of two-phase PTS scenarios within the next years

  2. Thermal shock fracture of graphite armor plate under the heat load of plasma disruption

    International Nuclear Information System (INIS)

    Horie, Tomoyoshi; Seki, Masahiro; Ohmori, Junji

    1989-01-01

    Experiments on the thermal shock brittle fracture of graphite plates were performed. Thermal loading which simulated a plasma disruption was produced by an electron beam facility. Pre-cracks produced on the surface propagated to the inside of the specimen even if the thermal stress on the surface was compressive. Two mechanisms are possible to produce tensile stress around the crack tip under thermal shock conditions. Temperature, thermal stress, and the stress intensity factor for the specimen were analyzed based on the finite element method for various heating conditions. The trend of experimental results under the asymmetric heating agrees qualitatively with the analytical results. This phenomenon is important for the design of plasma facing components made of graphite. Establishment of a lifetime prediction procedure including fatigue, fatigue crack growth, and brittle fracture is needed for graphite armors. (orig.)

  3. Microstructural effects associated to CTE mismatch for enhancing the thermal shock resistance of refractories

    International Nuclear Information System (INIS)

    Huger, M; Tessier-Doyen, N; Michaud, P; Chotard, T; Ota, T

    2011-01-01

    This work is devoted to the study of thermomechanical properties of several industrial and model refractory materials in relation with the evolution of their microstructure during thermal treatments. The aim is, in particular, to highlight the role of thermal expansion mismatches existing between phases which can induce damage at local scale. The resulting network of microcracks is well known to improve thermal shock resistance of materials, since it usually involves a significant decrease in elastic properties. Moreover, this network of microcracks can strongly affect the thermal expansion at low temperature and the stress-strain behaviour in tension. Even if these two last aspects are not so much documented in the literature, they certainly also constitute key points for the improvement of the thermal shock resistance of refractory materials. Evolution of damage during thermal cycling has been monitored by a specific ultrasonic device at high temperature. Beyond its influence on Young's modulus, this damage also allows to decrease the thermal expansion and to improve the non-linear character of the stress-strain curves determined in tension. The large increase in strain to rupture, which results from this non-linearity, is of great interest for thermal shock application.

  4. Behavior of deep flaws in a thick-wall cylinder under thermal shock loading

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1979-01-01

    Behavior of inner-surface flaws in thick-walled vessels was studied in a 991-mm OD x 152 mm wall x 1220 mm length cylinder with toughness properties similar to those for HSST Plate. The initial temperature of 93 0 C and a thermal shock medium of liquid nitrogen (-197 0 C) were employed. The initial flaw selected was a sharp, 16 mm deep, long (1220 mm) axial crack. Crack arrest methodology was shown to be valid for deep flaws under severe thermal shock

  5. Ion Thermalization and Electron Heating across Quasi-Perpendicular Shocks Observed by the MMS Mission

    Science.gov (United States)

    Chen, L. J.; Wilson, L. B., III; Wang, S.; Bessho, N.; Figueroa-Vinas, A.; Lai, H.; Russell, C. T.; Schwartz, S. J.; Hesse, M.; Moore, T. E.; Burch, J.; Gershman, D. J.; Giles, B. L.; Torbert, R. B.; Ergun, R.; Dorelli, J.; Strangeway, R. J.; Paterson, W. R.; Lavraud, B.; Khotyaintsev, Y. V.

    2017-12-01

    Collisionless shocks often involve intense plasma heating in space and astrophysical systems. Despite decades of research, a number of key questions concerning electron and ion heating across collisionless shocks remain unanswered. We `image' 20 supercritical quasi-perpendicular bow shocks encountered by the Magnetospheric Multiscale (MMS) spacecraft with electron and ion distribution functions to address how ions are thermalized and how electrons are heated. The continuous burst measurements of 3D plasma distribution functions from MMS reveal that the primary thermalization phase of ions occurs concurrently with the main temperature increase of electrons as well as large-amplitude wave fluctuations. Approaching the shock from upstream, the ion temperature (Ti) increases due to the reflected ions joining the incoming solar wind population, as recognized by prior studies, and the increase of Ti precedes that of the electrons. Thermalization in the form of merging between the decelerated solar wind ions and the reflected component often results in a decrease in Ti. In most cases, the Ti decrease is followed by a gradual increase further downstream. Anisotropic, energy-dependent, and/or nongyrotropic electron energization are observed in association with large electric field fluctuations in the main electron temperature (Te) gradient, motivating a renewed scrutiny of the effects from the electrostatic cross-shock potential and wave fluctuations on electron heating. Particle-in-cell (PIC) simulations are carried out to assist interpretations of the MMS observations. We assess the roles of instabilities and the cross-shock potential in thermalizing ions and heating electrons based on the MMS measurements and PIC simulation results. Challenges will be posted for future computational studies and laboratory experiments on collisionless shocks.

  6. Discrimination of Thermal versus Mechanical Effects of Shock on Rock Magnetic Properties of Spherically Shocked up to 10-160 GPa Basalt and Diabase

    Science.gov (United States)

    Bezaeva, N. S.; Swanson-Hysell, N.; Tikoo, S.; Badyukov, D. D.; Kars, M. A. C.; Egli, R.; Chareev, D. A.; Fairchild, L. M.

    2016-12-01

    Understanding how shock waves generated during hypervelocity impacts affect rock magnetic properties is key for interpreting the paleomagnetic records of lunar rocks, meteorites, and cratered planetary surfaces. Laboratory simulations of impacts show that ultra-high shocks may induce substantial post-shock heating of the target material. At high pressures (>10 GPa), shock heating occurs in tandem with mechanical effects, such as grain fracturing and creation of crystallographic defects and dislocations within magnetic grains. This makes it difficult to conclude whether shock-induced changes in the rock magnetic properties of target materials are primarily associated with mechanical or thermal effects. Here we present novel experimental methods to discriminate between mechanical and thermal effects of shock on magnetic properties and illustrate it with two examples of spherically shocked terrestrial basalt and diabase [1], which were shocked to pressures of 10 to >160 GPa, and investigate possible explanations for the observed shock-induced magnetic hardening (i.e., increase in remanent coercivity Bcr). The methods consist of i) conducting extra heating experiments at temperatures resembling those experienced during high-pressure shock events on untreated equivalents of shocked rocks (with further comparison of Bcr of shocked and heated samples) and ii) quantitative comparison of high-resolution first-order reversal curve (FORC) diagrams (field step: 0.5-0.7 mT) for shocked, heated and untreated specimens. Using this approach, we demonstrated that the shock-induced coercivity hardening in our samples is predominantly due to solid-state, mechanical effects of shock rather than alteration associated with shock heating. Indeed, heating-induced changes in Bcr in the post-shock temperature range were minor. Visual inspection of FORC contours (in addition to detailed analyses) reveals a stretching of the FORC distribution of shocked sample towards higher coercivities

  7. Time-dependent diffusive acceleration of test particles at shocks

    Energy Technology Data Exchange (ETDEWEB)

    Drury, L.O' C. (Dublin Inst. for Advanced Studies (Ireland))

    1991-07-15

    The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author).

  8. Time-dependent diffusive acceleration of test particles at shocks

    International Nuclear Information System (INIS)

    Drury, L.O'C.

    1991-01-01

    The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author)

  9. BOW SHOCK FRAGMENTATION DRIVEN BY A THERMAL INSTABILITY IN LABORATORY ASTROPHYSICS EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki-Vidal, F.; Lebedev, S. V.; Pickworth, L. A.; Swadling, G. F.; Skidmore, J.; Hall, G. N.; Bennett, M.; Bland, S. N.; Burdiak, G.; De Grouchy, P.; Music, J.; Suttle, L. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Ciardi, A. [Sorbonne Universités, UPMC Univ. Paris 6, UMR 8112, LERMA, F-75005, Paris (France); Rodriguez, R.; Gil, J. M.; Espinosa, G. [Departamento de Fisica de la Universidad de Las Palmas de Gran Canaria, E-35017 Las Palmas de Gran Canaria (Spain); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Hansen, E.; Frank, A., E-mail: f.suzuki@imperial.ac.uk [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

    2015-12-20

    The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the collision of two counterstreaming, supersonic plasma jets produced by an opposing pair of radial foil Z-pinches driven by the current pulse from the MAGPIE pulsed-power generator. The jets have different flow velocities in the laboratory frame, and the experiments are driven over many times the characteristic cooling timescale. The initially smooth bow shock rapidly develops small-scale nonuniformities over temporal and spatial scales that are consistent with a thermal instability triggered by strong radiative cooling in the shock. The growth of these perturbations eventually results in a global fragmentation of the bow shock front. The formation of a thermal instability is supported by analysis of the plasma cooling function calculated for the experimental conditions with the radiative packages ABAKO/RAPCAL.

  10. Thermal Shielding of the Shock Absorber to a Seal of a Hot-cell Cask

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K. S.; Lee, J. C.; Kim, K. Y.; Seo, C. S.; Seo, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    In order to safely transport the radioactive waste arising from the hot test of ACP(Advanced Spent Fuel Conditioning Process) a shipping package is required. Therefore KAERI is developing a shipping package to transport the radioactive waste arising in the ACPF during a hot test. Regulatory requirements for a Type B package are specified in the Korea MOST Act 2008-69, IAEA Safety Standard Series No. TS-R-1, and US 10 CFR Part. These regulatory guidelines classify the hot cell cask as a Type B package, and state that the Type B package for transporting radioactive materials should be able to withstand a test sequence consisting of a 9 m drop onto an unyielding surface, a 1 m drop onto a puncture bar, and a 30 minute fully engulfing fire. Greiner et al. performed a research on the thermal protection provided by shock absorbers by using CAFE computer code. This paper discusses the experimental approach used to simulate the response of the hot cell cask to fire in a furnace with chamber dimensions of 300 cm(W) x 400 cm(L) x 200 cm(H) by using a 1/2 scale model which was damaged by both a 9 m drop test and a 1 m puncture test

  11. Thermal chemical-mechanical reactive flow model of shock initiation in solid explosives

    International Nuclear Information System (INIS)

    Nicholls, A.L. III; Tarver, C.M.

    1998-01-01

    The three dimensional Arbitrary Lagrange Eulerian hydrodynamic computer code ALE3D with fully coupled thermal-chemical-mechanical material models provides the framework for the development of a physically realistic model of shock initiation and detonation of solid explosives. The processes of hot spot formation during shock compression, subsequent ignition of reaction or failure to react, growth of reaction in individual hot spots, and coalescence of reacting hot spots during the transition to detonation can now be modeled using Arrhenius chemical kinetic rate laws and heat transfer to propagate the reactive flow. This paper discusses the growth rates of reacting hot spots in HMX and TATB and their coalescence during shock to detonation transition. Hot spot deflagration rates are found to be fast enough to consume explosive particles less than 10 mm in diameter during typical shock duration times, but larger particles must fragment and create more reactive surface area in order to be rapidly consumed

  12. Prevention against fragile fracture in PWR pressure vessel in the presence of pressurized thermal shock

    International Nuclear Information System (INIS)

    Carmo, E.G.D. do; Oliveira, L.F.S. de; Roberty, N.C.

    1984-01-01

    A method for the determination of operational limit curves (primary pressure versus temperature) for PWR is presented. Such curves give the operators indications related to the safety status of the plant concerning the possibility of a pressurized thermal shock. The method begins by a thermal analysis for several postulated transients, followed by the determination of the thermomechanical stresses in the vessel and finally it makes use of the linear elasticity fracture mechanics. Curves are shown for a typical PWR. (Author) [pt

  13. Model of fragmentation of limestone particles during thermal shock and calcination in fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, J.; Pikkarainen, T.; Tourunen, A.; Rasanen, M.; Jantti, T. [VTT Technical Research Center, Jyvaskyla (Finland)

    2008-11-15

    Fragmentation of limestone due to thermal shock and calcination in a fluidised bed was studied through experiments and modelling. The time for heating was estimated by model calculations and the time for calcination by measurements. Fragmentation due to thermal shock was carried out by experiments in a CO{sub 2} atmosphere in order to prevent the effect of calcination. It was found to be much less than fragmentation due to calcination. Average particle sizes before and after fragmentation are presented for several types of limestone. The effects of particle size and gas composition on the primary fragmentation were studied through experiments. Increasing the fluidisation velocity increased the tendency to fragment. The evolution of the particle size distribution (PSD) of limestone particles due to thermal shock and during calcination (or simultaneous calcination and sulphation) were calculated using a population balance model. Fragmentation due to thermal shock is treated as an instantaneous process. The fragmentation frequency during calcination is presented as exponentially decaying over time. In addition to the final PSD, this model also predicts the PSD during the calcination process. The fragmentation was practically found to end after 10 min. Furthermore. a population balance method to calculate the particle size distribution and amount of limestone in fluidised beds in dynamic and steady state, when feeding history is known, is presented.

  14. Effect of magnesium aluminum silicate glass on the thermal shock resistance of BN matrix composite ceramics

    NARCIS (Netherlands)

    Cai, Delong; Jia, Dechang; Yang, Zhihua; Zhu, Qishuai; Ocelik, Vaclav; Vainchtein, Ilia D.; De Hosson, Jeff Th M.; Zhou, Yu

    The effects of magnesium aluminum silicate (MAS) glass on the thermal shock resistance and the oxidation behavior of h-BN matrix composites were systematically investigated at temperature differences from 600 degrees C up to 1400 degrees C. The retained strength rate of the composites rose with the

  15. Variable flaw shape analysis for a reactor vessel under pressurized thermal shock loading

    International Nuclear Information System (INIS)

    Yang, C.Y.; Bamford, W.H.

    1984-01-01

    A study has been conducted to characterize the response of semi-elliptic surface flaws to thermal shock conditions which can result from safety injection actuation in nuclear reactor vessels. A methodology was developed to predict the behavior of a flaw during sample pressurized thermal shock events. The effects of a number of key variables on the flaw propagation were studied, including fracture toughness of the material and its gradient through the thickness, irradiation effects, effects of warm prestressing, and effects of the stainless steel cladding. The results of these studies show that under thermal shock loading conditions the flaw always tends to elongate along the vessel inside surface from the initial aspect ratio. However, the flaw shape always remains finite rather than becoming continuously long, as has often been assumed in earlier analyses. The final shape and size of the flaws were found to be rather strongly dependent on the effects of warm prestressing and the distribution of neutron flux. The improved methodology results in a more accurate and more realistic treatment of flaw shape changes during thermal shock events and provides the potential for quantifying additional margins for reactor vessel integrity analyses

  16. Molecular Line Emission from Multifluid Shock Waves. I. Numerical Methods and Benchmark Tests

    Science.gov (United States)

    Ciolek, Glenn E.; Roberge, Wayne G.

    2013-05-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part, independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other, equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are Lt magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests confirming its accuracy are presented, including (1) MHD wave packets ranging over orders of magnitude in length- and timescales, (2) early evolution of multifluid shocks caused by two colliding clouds, and (3) a multifluid shock with mass transfer between the fluids by cosmic-ray ionization and ion-electron recombination, demonstrating the effect of ion mass loading on magnetic precursors of MHD shocks. An exact solution to an MHD Riemann problem forming the basis for an approximate numerical solver used in the homogeneous part of our scheme is presented, along with derivations of the analytic benchmark solutions and tests showing the convergence of the numerical algorithm.

  17. MOLECULAR LINE EMISSION FROM MULTIFLUID SHOCK WAVES. I. NUMERICAL METHODS AND BENCHMARK TESTS

    International Nuclear Information System (INIS)

    Ciolek, Glenn E.; Roberge, Wayne G.

    2013-01-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part, independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other, equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are << magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests confirming its accuracy are presented, including (1) MHD wave packets ranging over orders of magnitude in length- and timescales, (2) early evolution of multifluid shocks caused by two colliding clouds, and (3) a multifluid shock with mass transfer between the fluids by cosmic-ray ionization and ion-electron recombination, demonstrating the effect of ion mass loading on magnetic precursors of MHD shocks. An exact solution to an MHD Riemann problem forming the basis for an approximate numerical solver used in the homogeneous part of our scheme is presented, along with derivations of the analytic benchmark solutions and tests showing the convergence of the numerical algorithm.

  18. Comparison of Shock Response Spectrum for Different Gun Tests

    Directory of Open Access Journals (Sweden)

    J.A. Cordes

    2013-01-01

    Full Text Available The Soft Catch Gun at Picatinny Arsenal is regularly used for component testing. Most shots contain accelerometers which record accelerations as a function of time. Statistics of accelerometer data indicate that the muzzle exit accelerations are, on average, higher than tactical firings. For that reason, Soft Catch Gun tests with unusually high accelerations may not be scored for Lot Acceptance Tests (LAT by some customers. The 95/50 Normal Tolerance Limit (NTL is proposed as a means of determining which test results should be scored. This paper presents comparisons of Shock Response Spectra (SRS used for the 95/50 scoring criteria. The paper also provides a Discussion Section outlining some concerns with scoring LAT results based on test results outside of the proposed 95/50 criteria.

  19. Design and testing of a shock absorber for a type I container

    International Nuclear Information System (INIS)

    Sappok, M.; Beine, B.; Rittscher, D.; Jais, M.

    1994-01-01

    A simple method of designing a shock absorber to protect a type B cast-iron container is developed. The results of deformation tests of the structural material (steel pipes) used for the shock absorber are presented. The accelerations and strains measured during the 9m drop tests of the container with the shock absorber are compared with the theoretical results of the calculations for the shock absorber design. ((orig.))

  20. THERMAL X-RAY EMISSION FROM THE SHOCKED STELLAR WIND OF PULSAR GAMMA-RAY BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Zabalza, V.; Paredes, J. M. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E08028 Barcelona (Spain); Bosch-Ramon, V., E-mail: vzabalza@am.ub.es [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

    2011-12-10

    Gamma-ray-loud X-ray binaries are binary systems that show non-thermal broadband emission from radio to gamma rays. If the system comprises a massive star and a young non-accreting pulsar, their winds will collide producing broadband non-thermal emission, most likely originated in the shocked pulsar wind. Thermal X-ray emission is expected from the shocked stellar wind, but until now it has neither been detected nor studied in the context of gamma-ray binaries. We present a semi-analytic model of the thermal X-ray emission from the shocked stellar wind in pulsar gamma-ray binaries, and find that the thermal X-ray emission increases monotonically with the pulsar spin-down luminosity, reaching luminosities of the order of 10{sup 33} erg s{sup -1}. The lack of thermal features in the X-ray spectrum of gamma-ray binaries can then be used to constrain the properties of the pulsar and stellar winds. By fitting the observed X-ray spectra of gamma-ray binaries with a source model composed of an absorbed non-thermal power law and the computed thermal X-ray emission, we are able to derive upper limits on the spin-down luminosity of the putative pulsar. We applied this method to LS 5039, the only gamma-ray binary with a radial, powerful wind, and obtain an upper limit on the pulsar spin-down luminosity of {approx}6 Multiplication-Sign 10{sup 36} erg s{sup -1}. Given the energetic constraints from its high-energy gamma-ray emission, a non-thermal to spin-down luminosity ratio very close to unity may be required.

  1. The Acceleration of Thermal Protons and Minor Ions at a Quasi-Parallel Interplanetary Shock

    Science.gov (United States)

    Giacalone, J.; Lario, D.; Lepri, S. T.

    2017-12-01

    We compare the results from self-consistent hybrid simulations (kinetic ions, massless fluid electrons) and spacecraft observations of a strong, quasi-parallel interplanetary shock that crossed the Advanced Composition Explorer (ACE) on DOY 94, 2001. In our simulations, the un-shocked plasma-frame ion distributions are Maxwellian. Our simulations include protons and minor ions (alphas, 3He++, and C5+). The interplanetary shock crossed both the ACE and the Wind spacecraft, and was associated with significant increases in the flux of > 50 keV/nuc ions. Our simulation uses parameters (ion densities, magnetic field strength, Mach number, etc.) consistent with those observed. Acceleration of the ions by the shock, in a manner similar to that expected from diffusive shock acceleration theory, leads to a high-energy tail in the distribution of the post-shock plasma for all ions we considered. The simulated distributions are directly compared to those observed by ACE/SWICS, EPAM, and ULEIS, and Wind/STICS and 3DP, covering the energy range from below the thermal peak to the suprathermal tail. We conclude from our study that the solar wind is the most significant source of the high-energy ions for this event. Our results have important implications for the physics of the so-called `injection problem', which will be discussed.

  2. Shock-tunnel combustor testing for hypersonic vehicles

    Science.gov (United States)

    Loomis, Mark P.

    1994-01-01

    Proposed configurations for the next generation of transatmospheric vehicles will rely on air breathing propulsion systems during all or part of their mission. At flight Mach numbers greater than about 7 these engines will operate in the supersonic combustion ramjet mode (scramjet). Ground testing of these engine concepts above Mach 8 requires high pressure, high enthalpy facilities such as shock tunnels and expansion tubes. These impulse, or short duration facilities have test times on the order of a millisecond, requiring high speed instrumentation and data systems. One such facility ideally suited for scramjet testing is the NASA-Ames 16-Inch shock tunnel, which over the last two years has completed a series of tests for the NASP (National Aero-Space Plane) program at simulated flight Mach numbers ranging from 12-16. The focus of the experimental programs consisted of a series of classified tests involving a near-full scale hydrogen fueled scramjet combustor model in the semi-free jet method of engine testing whereby the compressed forebody flow ahead of the cowl inlet is reproduced (see appendix A). The AIMHYE-1 (Ames Integrated Modular Hypersonic Engine) test entry for the NASP program was completed in April 1993, while AIMHYE-2 was completed in May 1994. The test entries were regarded as successful, resulting in some of the first data of its kind on the performance of a near full scale scramjet engine at Mach 12-16. The data was distributed to NASP team members for use in design system verification and development. Due to the classified nature of the hardware and data, the data reports resulting from this work are classified and have been published as part of the NASP literature. However, an unclassified AIAA paper resulted from the work and has been included as appendix A. It contains an overview of the test program and a description of some of the important issues.

  3. Contribution for the improvement of pressurized thermal shock assessment methodologies in PWR pressure vessels

    International Nuclear Information System (INIS)

    Gomes, Paulo de Tarso Vida

    2005-01-01

    The structural integrity assessment of nuclear reactor pressure vessel, concerned to Pressurized Thermal Shock (PTS) accidents, became a necessity and has been investigated since the eighty's. The recognition of the importance of PTS assessment has led the international nuclear technology community to devote a considerable research effort directed to the complete integrity assessment process of the Reactor Pressure Vessels (VPR). Researchers in Europe, Japan and U.S.A. have concentrated efforts in the VPR structural and fracture analysis, conducting experiments to best understand how specific factors act on the behavior of discontinuities, under PTS loading conditions. The main goal of this work is to study de structural behavior of an 'in scale' PWR nuclear reactor pressure vessel model, containing actual discontinuities, under loading conditions generated by a pressurized thermal shock. To construct the pressure vessel model utilized in this research, the approach developed by Barroso (1995) and based on likelihood studies, related to thermal-hydraulic behavior during the PTS was employed. To achieve the objective of this research, a new methodology to generate cracks, with known geometry and localization in the vessel model wall was developed. Additionally, an hydraulic circuit, able to flood the vessel model, heated to 300 deg C, with 10 m 3 of water at 8 deg C, in 170 seconds, was built. Thermo-hydraulic calculations using RELAP5/M0D 3.2.2γ computational code were done, to estimate the temperature profiles during the cooling time. The resulting data subsidized the thermo-structural calculations that were accomplished using ANSYS 7.01 computational code, for both 2D and 3D models. So, the stress profiles obtained with these calculations were associated with fracture mechanics concepts, to assess the crack growth behavior in the VPR model wall. After the PTS test, the VPR model was submitted to destructive and non-destructive inspections. The results

  4. Cyclic elastic analysis of a PWR nozzle subjected to a repeated thermal shock

    International Nuclear Information System (INIS)

    Locci, J.M.; Prost, J.P.

    1979-01-01

    In the primary piping system of a PWR nuclear power plant, some nozzles are subjected to strong thermal shocks due to sudden thermal variations in the internal water flow. The thermal gradients are sufficiently high to induce general elastic plastic behaviour. The design of these nozzles using the simplified elastic plastic analysis given in the ASME III Code NB-3200 generally leads to a very high usage factor. The aim of this work is to show by giving an example that a complete cyclic elastic plastic analysis makes it possible to considerably reduce the usage factor. (orig.)

  5. ENDF/B Thermal Data Testing

    CERN Document Server

    McCrosson, F J

    2001-01-01

    The thermal data testing group is concerned with establishing the merit of ENDF/B cross sections for the analysis of thermal systems. The integral experiments used in the testing are designed to analyze each of the phenomena identified in the familiar four-factor formula. For brevity, only the testing of the cross sections in uranium systems is described in this report.

  6. Assessment of thermal shock induced damage in silicon carbide fibre reinforced glass matrix composites

    Directory of Open Access Journals (Sweden)

    Boccaccini, A. R.

    1998-09-01

    Full Text Available The development of microstructural damage in silicon carbide fibre (Nicalon™ reinforced glass matrix composite samples subjected to thermal shock was investigated by using a nondestructive forced resonance technique and fibre push out indentation tests. Thermal shock testing involved quenching samples in a water bath maintained at room temperature from a high temperature (650ºC. Changes in the Young's modulus and internal friction of the samples with increasing number of shocks were measured accurately by the forced resonance technique. Fibre push-out tests showed no significant changes in the properties of the fibre-matrix interface, indicating that damage in the composite was concentrated mainly in the development of matrix microcracking. It was also shown that the internal friction is a very sensitive parameter by which to detect the onset and development of such microcracking. A simple semi-empirical model is proposed to correlate the internal friction level with the microcracking density in the glass matrix. Finally, the relevance of detecting nondestructively the existence of microcracks in the glass matrix, before any significant interfacial degradation occurs, is emphasized, in conextion with the possibility of inducing a crack healing process by a thermal treatment (annealing, taking advantage of the viscous flow properties of the glass.

    El desarrollo de daño microestructural en materiales compuestos de matriz de vidrio reforzados con fibras de carburo de silicio (Nicalon™ sometidos a choque térmico fue investigado mediante la técnica no-destructiva de resonancia forzada y por mediciones de indentación "push-out" de fibras. Los ensayos de choque térmico involucraron el enfriamiento brusco en un baño de agua a temperatura ambiente de las piezas previamente calentadas a una temperatura elevada (650ºC. La técnica de resonancia forzada permitió medir cambios en el módulo de Young de elasticidad y en la fricci

  7. STRESSES IN CEMENT-CONCRETE PAVEMENT SURFACING CAUSED BY THERMAL SHOCK

    Directory of Open Access Journals (Sweden)

    M. K. Pshembaev

    2016-01-01

    Full Text Available It is necessary to mention specially so-called thermal shock among various impacts on highway surface. Ice layer is formed on a concrete surface during the winter period of pavement surfacing operation. Sodium chloride which lowers temperature of water-ice transition temperature and causes ice thawing at negative temperature is usually used to remove ice from the pavement surface. Consequently, temperature in the concrete laying immediately under a thawing ice layer is coming down with a run that leads to significant stresses. Such phenomenon is known as a thermal shock with a meaning of local significant change in temperature. This process is under investigation, it has practical importance for an estimation of strength and longevity of a cement-concrete pavement surfacing and consequently it is considered as rather topical issue. The purpose of investigations is to develop a mathematical model and determination of shock blow permissible gradients for a cementconcrete road covering. Finite difference method has been used in order to determine stressed and deformed condition of the cement-concrete pavement surfacing of highways. A computer program has been compiled and it permits to carry out calculation of a road covering at various laws of temperature distribution in its depth. Regularities in distribution of deformation and stresses in the cement-concrete pavement surfacing of highways at thermal shock have been obtained in the paper. A permissible parameter of temperature distribution in pavement surfacing thickness has been determined in the paper. A strength criterion based on the process of micro-crack formation and development in concrete has been used for making calculations. It has been established that the thermal shock causes significant temperature gradients on the cement-concrete surfacing that lead to rather large normal stresses in the concrete surface layer. The possibility of micro-crack formation in a road covering is

  8. Theoretical Research on Thermal Shock Resistance of Ultra-High Temperature Ceramics Focusing on the Adjustment of Stress Reduction Factor

    Directory of Open Access Journals (Sweden)

    Daining Fang

    2013-02-01

    Full Text Available The thermal shock resistance of ceramics depends on not only the mechanical and thermal properties of materials, but also the external constraint and thermal condition. So, in order to study the actual situation in its service process, a temperature-dependent thermal shock resistance model for ultra-high temperature ceramics considering the effects of the thermal environment and external constraint was established based on the existing theory. The present work mainly focused on the adjustment of the stress reduction factor according to different thermal shock situations. The influences of external constraint on both critical rupture temperature difference and the second thermal shock resistance parameter in either case of rapid heating or cooling conditions had been studied based on this model. The results show the necessity of adjustment of the stress reduction factor in different thermal shock situations and the limitations of the applicable range of the second thermal shock resistance parameter. Furthermore, the model was validated by the finite element method.

  9. Used fuel rail shock and vibration testing options analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Best, Ralph E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Klymyshyn, Nicholas A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maheras, Steven J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-25

    The objective of the rail shock and vibration tests is to complete the framework needed to quantify loads of fuel assembly components that are necessary to guide materials research and establish a technical basis for review organizations such as the U.S. Nuclear Regulatory Commission (NRC). A significant body of experimental and numerical modeling data exists to quantify loads and failure limits applicable to normal conditions of transport (NCT) rail transport, but the data are based on assumptions that can only be verified through experimental testing. The test options presented in this report represent possible paths for acquiring the data that are needed to confirm the assumptions of previous work, validate modeling methods that will be needed for evaluating transported fuel on a case-by-case basis, and inform material test campaigns on the anticipated range of fuel loading. The ultimate goal of this testing is to close all of the existing knowledge gaps related to the loading of used fuel under NCT conditions and inform the experiments and analysis program on specific endpoints for their research. The options include tests that would use an actual railcar, surrogate assemblies, and real or simulated rail transportation casks. The railcar carrying the cradle, cask, and surrogate fuel assembly payload would be moved in a train operating over rail track modified or selected to impart shock and vibration forces that occur during normal rail transportation. Computer modeling would be used to help design surrogates that may be needed for a rail cask, a cask’s internal basket, and a transport cradle. The objective of the design of surrogate components would be to provide a test platform that effectively simulates responses to rail shock and vibration loads that would be exhibited by state-of-the-art rail cask, basket, and/or cradle structures. The computer models would also be used to help determine the placement of instrumentation (accelerometers and strain gauges

  10. Comparison of the thermal shock performance of different tungsten grades and the influence of microstructure on the damage behaviour

    International Nuclear Information System (INIS)

    Wirtz, M; Linke, J; Pintsuk, G; Singheiser, L; Uytdenhouwen, I

    2011-01-01

    The thermal shock performances of two new tungsten grades with 1 and 5 wt% of tantalum were characterized with the electron beam facility JUDITH 1. As a reference material, ultra-high-purity tungsten (W-UHP) with a purity of 99.9999 wt% was used. The induced thermal shock crack networks and surface modifications were analysed by a scanning electron microscope, light microscopy and laser profilometry. Damage and cracking thresholds were defined for all materials as a function of absorbed power density and base temperature. The materials showed significantly different thermal shock behaviour, which is, among others, expressed by differences in cracking patterns, i.e. crack distance and depth. These results allow us to quantify the influence of the materials' mechanical and thermal properties on the thermal shock performance. Furthermore, the specific grain structure of the materials has a significant influence on crack propagation towards the bulk material.

  11. Response of beryllium to severe thermal shocks -simulation of disruption and vertical displacement events in future thermonuclear devices

    Energy Technology Data Exchange (ETDEWEB)

    Linke, J.; Duwe, R.; Roedig, M.; Schuster, A. [Association Euratom-Forschungszentrum Juelich GmbH (Germany); Merola, M.; Qian, R.H.

    1998-01-01

    Beryllium will play an important role for plasma facing components in next step thermonuclear fusion devices such as ITER. In particular for the first wall beryllium will be used with an armor thickness of several millimeters. However, during plasma instabilities they will experience severe thermal shocks. Here plasma disruptions with deposited energy densities of several ten MJm{sup -2} are the most essential damaging mechanism. However, a signifant fraction of the incident energy will be absorbed by a dense cloud of ablation vapor, hence reducing the effective energy density at the beryllium surface to values in the order of 10 MJm{sup -2}. To investigate the material response to all these plasma instabilities thermal shock tests on small scale test coupons (disruption effects) and on actively cooled divertor modules (VDEs) have been performed in the electron beam test facility JUDITH at ITER relevant surface heat loads. These tests have been performed on different bulk beryllium grades and on plasma sprayed coatings; the influence of pulse duration, power density, and temperature effects has been investigated experimentally. Detailed in-situ diagnostics (for beam characterization, optical pyrometry etc.) and post mortem analyses (profilometry, metallography, optical and electron microscopy) have been applied to quantify the resulting material damage. 1D- and 2D models have developed to verify the experimental results obtained in the electron beam simulation experiments. (J.P.N.)

  12. Thermal Conductivity Analysis and Lifetime Testing of Suspension Plasma-Sprayed Thermal Barrier Coatings

    Directory of Open Access Journals (Sweden)

    Nicholas Curry

    2014-08-01

    Full Text Available Suspension plasma spraying (SPS has become an interesting method for the production of thermal barrier coatings for gas turbine components. The development of the SPS process has led to structures with segmented vertical cracks or column-like structures that can imitate strain-tolerant air plasma spraying (APS or electron beam physical vapor deposition (EB-PVD coatings. Additionally, SPS coatings can have lower thermal conductivity than EB-PVD coatings, while also being easier to produce. The combination of similar or improved properties with a potential for lower production costs makes SPS of great interest to the gas turbine industry. This study compares a number of SPS thermal barrier coatings (TBCs with vertical cracks or column-like structures with the reference of segmented APS coatings. The primary focus has been on lifetime testing of these new coating systems. Samples were tested in thermo-cyclic fatigue at temperatures of 1100 °C for 1 h cycles. Additional testing was performed to assess thermal shock performance and erosion resistance. Thermal conductivity was also assessed for samples in their as-sprayed state, and the microstructures were investigated using SEM.

  13. A Literature Review of Shock Sensitivity Changes of TATB Due to Thermal Cycling

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, Boyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Mechanical Engineering

    2016-07-15

    Insensitive high explosives (IHEs) based on 1,3,5-triamino 2,4,6-trinitro-benzene (TATB) are the IHEs of choice for use in nuclear warheads over conventional high explosives when safety is the only consideration, because they are very insensitive to thermal or mechanical initiation stimuli. It is this inherent insensitivity to high temperatures, shock, and impact, which provides detonation design challenges when designing TATB explosive systems while at the same time providing a significant level of protection against accidental initiation. Although classified as IHE, over the past few years the focus on explosive safety has demonstrated that the shock sensitivity of TATB is influenced with respect to temperature. A number of studies have been performed on TATB and TATB formulations, plastic bonded explosives (PBX) 9502, and LX-17-01 (LX-17), which demonstrates the increase in shock sensitivity of the explosive after it has been preheated or thermally cycled over various temperature ranges. Many studies suggest the change in sensitivity is partly due to the decomposition rates of the temperature elevated TATB. Others point to the coefficient of thermal expansion, the crystalline structures of TATB and/or the combination of all factors, which create voids which can become active hot spots. During thermal cycling, TATB is known to undergo an irreversible increase in specific volume called ratchet growth. This increase in specific volume correlates to a decrease in density. This decrease in density and increase in volume, demonstrate the creations of additional void spaces which could serve as potential new initiation hot spots thus, increasing the overall sensitivity of the HE. This literature review evaluates the published works to understand why the shock sensitivity of TATB-based plastic bonded explosives (PBXs) changes with temperature.

  14. Effect of thermal shock on mechanical properties of injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Takahashi, Yutaka; Hamanaka, Ippei; Shimizu, Hiroshi

    2012-07-01

    This study investigated the effect of thermal shock on the mechanical properties of injection-molded thermoplastic denture base resins. Four thermoplastic resins (two polyamides, one polyethylene terephthalate, one polycarbonate) and, as a control, a conventional heat-polymerized polymethyl methacrylate (PMMA), were tested. Specimens of each denture base material were fabricated according to ISO 1567 and were either thermocycled or not thermocycled (n = 10). The flexural strength at the proportional limit (FS-PL), the elastic modulus and the Charpy impact strength of the denture base materials were estimated. Thermocycling significantly decreased the FS-PL of one of the polyamides and the PMMA and it significantly increased the FS-PL of one of the polyamides. In addition, thermocycling significantly decreased the elastic modulus of one of the polyamides and significantly increased the elastic moduli of one of the polyamides, the polyethylene terephthalate, polycarbonate and PMMA. Thermocycling significantly decreased the impact strength of one of the polyamides and the polycarbonate. The mechanical properties of injection-molded thermoplastic denture base resins changed after themocycling.

  15. Improvement of thermal shock resistance of isotropic graphite by Ti-doping

    International Nuclear Information System (INIS)

    Lopez-Galilea, I.; Ordas, N.; Garcia-Rosales, C.; Lindig, S.

    2009-01-01

    Ti-doped isotropic graphite is a promising candidate material for the strike point area of the ITER divertor due to its reduced chemical erosion by hydrogen bombardment and its high thermal shock resistance, mainly due the catalytic effect of TiC on the graphitization leading to an increase of thermal conductivity and to higher mechanical strength. Several manufacturing parameters such as oxidative stabilization treatment, carbonization cycle, graphitization temperature and dwell time during graphitization have been investigated in order to establish a relationship between these parameters and the final properties.

  16. Improvement of thermal shock resistance of isotropic graphite by Ti-doping

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Galilea, I. [Inmaculada Lopez-Galilea, CEIT and Tecnun (University of Navarra), Po de Manuel Lardizabal, 15 E-20018 San Sebastian (Spain)], E-mail: ilopez@ceit.es; Ordas, N.; Garcia-Rosales, C. [Inmaculada Lopez-Galilea, CEIT and Tecnun (University of Navarra), Po de Manuel Lardizabal, 15 E-20018 San Sebastian (Spain); Lindig, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

    2009-04-30

    Ti-doped isotropic graphite is a promising candidate material for the strike point area of the ITER divertor due to its reduced chemical erosion by hydrogen bombardment and its high thermal shock resistance, mainly due the catalytic effect of TiC on the graphitization leading to an increase of thermal conductivity and to higher mechanical strength. Several manufacturing parameters such as oxidative stabilization treatment, carbonization cycle, graphitization temperature and dwell time during graphitization have been investigated in order to establish a relationship between these parameters and the final properties.

  17. Fast qualification using thermal shock combined with moisture absorption

    NARCIS (Netherlands)

    Ma, X.S.; Zhang, G.Q.; Jansen, K.M.B.; Driel, van W.D.; Sluis, van der O.; Ernst, L.J.; Regard, C.; Gautier, C.; Fremont, H.

    2009-01-01

    Time to market is becoming one of the most important factors because of the fierce market competition. However, traditional reliability and interface toughness characterization tests take very long time. For example, moisture sensitivity level assessment (MSL1) will take 168 hours pre conditioning

  18. Pressurized thermal shock analysis in German nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Stefan; Braun, Michael [TUEV NORD Nuclear, Hannover (Germany)

    2015-03-15

    For more than 30 years TUeV NORD is a competent consultant in nuclear safety is-sues giving expert third party opinion to our clients. According to the German regulations the safety against brittle fracture has to be proved for the reactor pressure vessel (RPV) and with a new level of knowledge the proof has to be continuously updated with the development in international codes and standards like ASME, BS and RCC-M. The load of the RPV is a very complex transient pressure and temperature situation. Today these loading conditions can be modeled by thermal hydraulic calculations and new experimental results much more detailed than in the construction phase of German Nuclear Power Plants in the 1980s. Therefore, the proof against brittle fracture from the construction phase had to be updated for all German Nuclear Power Plants with the new findings of the loading conditions especially for a postulated small leakage in the main coolant line. The RPV consists of ferritic base material (about 250 mm) and austenitic cladding (about 6 mm) at the inner side. The base material and the cladding have different physical properties which have to be considered temperature dependently in the cal-culations. Radiation-embrittlement effects on the material are to be respected in the fracture mechanics assessment. The regions of the RPV of special interest are the core weld, the inlet and outlet nozzle region and the flange connecting weld zone. The fracture mechanics assessment is performed for normal and abnormal operating conditions and for accidents like LOCA (Loss of Coolant Accident). In this paper the German approach to fracture mechanics assessment to brittle fracture will be discussed from the point of view of a third party organization.

  19. Universal treatment of plumes and stresses for pressurized thermal shock evaluations

    International Nuclear Information System (INIS)

    Theofanous, T.G.; Angelini, S.; Yan, H.

    1991-01-01

    Thermally-induced stresses in a reactor pressure vessel wall, as a result of high-pressure safety injection, are an essential component of integrated risk analyses of pressurized thermal shock transients. Limiting cooldowns arise when this injection occurs under stagnated loop conditions which, in turn, correspond to a rather narrow range (in size) of small-break loss-of-coolant accidents. Moreover, at these conditions, the flow is thermally stratified, and in addition to the global cooldown, one must be concerned about the additional cooling potential due to the downcomer plumes formed by the cold streams pouring out of the cold legs. In the Nuclear Regulatory Commission's Integrated Pressurized Thermal Shock (IPTS) study, this stratification was calculated with the codes REMIX/NEWMIX. A comprehensive comparison with all available experimental data has currently been compiled. The stress analysis using this input was carried out at Oak Ridge National Laboratory using a one-dimensional approximation with the intent to conservatively bound the magnitude of thermal stresses

  20. Below-Ambient and Cryogenic Thermal Testing

    Science.gov (United States)

    Fesmire, James E.

    2016-01-01

    Thermal insulation systems operating in below-ambient temperature conditions are inherently susceptible to moisture intrusion and vapor drive toward the cold side. The subsequent effects may include condensation, icing, cracking, corrosion, and other problems. Methods and apparatus for real-world thermal performance testing of below-ambient systems have been developed based on cryogenic boiloff calorimetry. New ASTM International standards on cryogenic testing and their extension to future standards for below-ambient testing of pipe insulation are reviewed.

  1. Failure analysis of glass-ceramic insulators of shock tested vacuum (neutron) tubes

    International Nuclear Information System (INIS)

    Spears, R.K.

    1980-01-01

    Eight investigative techniques were used to examine the glass-ceramic insulators in vacuum (neutron) tubes. The insulators were extracted from units that had been subjected to low temperature mechanical shock tests. Two of the three units showed reduced neutron output after these tests and an insulator on one of these two was cracked completely through which probably occurred during shock testing. The objective of this study was to determine if any major differences existed between the insulators of these tubes. After eight analyses, it was concluded that no appreciable differences existed. It appeared that cracking of the one glass-ceramic sample was initiated at inner-sleeve interface voids. For this sample, the interface void density was much higher than is presently acceptable. All insulators were made with glass-ceramic having a Na 2 O content of 4.6 wt%. An increased Na 2 O content will cause an increase in the coefficient of expansion and will reduce the residual stress level since the molybdenum has a higher coefficient of thermal expansion than the insulator. Thus, it is believed that a decrease in interface voids and an increase in Na 2 O should aid in reduced cracking of the insulator during these tests

  2. Constant load supports attenuating shocks and vibrations for networks of pipes submitted to large thermal dilatation

    International Nuclear Information System (INIS)

    Prisecaru, Ilie; Panait; Adrian; Serban, Viorel; Ciocan, George; Androne, Marian; Florea, Ioana; State, Elena

    2004-01-01

    Full text: To avoid some drawbacks in the classical supports employed currently in networks of pipes it was conceived, designed, built and experimentally tested a new type of constant load supports which attenuate largely the shocks and vibrations for networks of pipes subjected to large thermal dilatation. These supports are particularly needed for solving the severe problems of the vibrations in networks of pipes in thermoelectric stations, nuclear power plants, or heavy water production plants. These supports allow building networks of new types, more reliable and of lower cost. The new type of support was developed on the basis of a number of patents protected by OSIM. It has a simple structure, ensures a secure functioning without blocking or other kinds of failures and is resistant to a very large variety of stresses. The new type of support of constant load avoids the drawbacks in classical supports i.e. the stress/deformation diagram is practically independent of stress level. The characteristic of the support is geometrically non-linear and presents a plateau with a small slope over a rather large deformation range which results from a serially mounted structure of sandwiches the deformation of which is controlled by a system of deforming central and peripheral pieces. The new supports of constant load, called SERB-PIPE, present a controlled elasticity and a high degree of damping as the package of elastic blades (the sandwich structure) is made of two sub-packages with relative movements what ensure the attenuation of the shocks and vibrations produced by the fluid flow within the pipes and or by seismic motions. By contrast with classical supports, the new supports have a simple structure and a high reliability. Breakdown under stress leading to severe changes in the stress distribution in pipe networks, which could generate overloads in pipes and over-loading in other supports, cannot occur. One can also mention that these supports can be built in a

  3. Testing the Asymmetry of Shocks with Euro Area

    Directory of Open Access Journals (Sweden)

    Marius-Corneliu MARINAŞ

    2012-01-01

    Full Text Available The objective of this study is to identify the demand and supply shocks affecting 13 EU member states and to estimate their degree of correlation with the Euro area shocks. This research ensures identifying the asymmetry of shocks degree with the monetary union, depending on which it’s judging the desirability of adopting a single currency. The analysis is also useful for the economies outside the Euro area, because they are strongly commercial and financial integrated especially with the core economies from union. Applying the Blanchard and Quah methodology to estimate the shocks in the period from 1998:1- 2010:3, I have found a weak and negative correlation between demand shocks and a medium to high correlation of the supply shocks. The results obtained suggest the presence of a structural convergence process with the Euro area, in the context of domestic macroeconomic policies rather different, both inside and outside the monetary union.

  4. Thermal histories of chondrules in solar nebula shocks, including the effect of molecular line cooling

    Science.gov (United States)

    Morris, Melissa A.

    Chondrules are millimeter-sized, silicate (mostly ferromagnesian) igneous spheres found within chondritic meteorites. They are some of the oldest materials in our Solar System, having formed within a few million years of its birth. Chondrules were melted at high temperature (over 1800 K), while they were free-floating objects in the early solar nebula. Their petrology and chemistry constrain their formation, especially their thermal histories. Chondrules provide some of the most powerful constraints on conditions in the solar nebula. Models in which chondrule precursors melted by passage through solar nebula shocks are very promising, and meet most constraints on chondrule formation in broad brush. However, these models have been lacking in some of the relevant physics. Previous shock models have used incorrect approximations to the input radiation boundary condition, and the opacity of solids has been treated simply. Most important, a proper treatment of cooling due to molecular line emission has not been included. In this thesis, the shock model is significantly improved in order to determine if it remains consistent with observational constraints. The appropriate boundary condition for the input radiation and the proper method for calculation of the opacity of solids are determined, and a complete treatment of molecular line cooling due to water is included. Previous estimates of the effect of line cooling predicted chondrule cooling rates in excess of 10,000 K per hour. However, once molecular line cooling due to water was incorporated into the full shock model, it was found that line cooling has a minimal effect on the thermal histories of gas and chondrules. This behavior is attributed mostly to the thermal buffering of the gas due to hydrogen dissociation and recombination, which tends to keep the gas temperature at approximately 2000 K until the column densities of water become optically thick to line emission. Chondrule cooling rates in the range of 10

  5. Prevention of crack initiation in valve bodies under thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Delmas, J.; Coppolani, P.

    1996-12-01

    On site and testing experience has shown that cracking in valves affects mainly the stellite hardfacing on seats and discs but may also be a concern for valve bodies. Metallurgical investigations conducted by EDF laboratories on many damaged valves have shown that most of the damage had either a chemical, manufacturing, or operating origin with a strong correlation between the origins and the type of damage. The chemical defects were either excess ferritic dilution of stellite or excess carburizing. Excess carburizing leads to a too brittle hardfacing which cracks under excessive stresses induced on the seating surfaces, via the stem, by too high operating thrusts. The same conditions can also induce cracks of the seats in the presence, in the hardfacing, of hidden defects generated during the welding process. Reduction of the number of defects results first from controls during manufacturing, mainly in the thickness of stellite. On the other hand, maintenance must be fitted to the type of defect. In-situ lapping may lead to release of cobalt, resulting in contamination of the circuit. Furthermore, it is ineffectual in the case of a crack through the seating surface, as is often found on globe valves. The use of new technologies of valves with removable seats and cobalt-free alloys solves permanently this kind of problem.

  6. Modeling properties of chromospheric evaporation driven by thermal conduction fronts from reconnection shocks

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, Sean; Longcope, Dana [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2014-09-01

    Magnetic reconnection in the corona results in contracting flare loops, releasing energy into plasma heating and shocks. The hydrodynamic shocks produced in this manner drive thermal conduction fronts (TCFs) which transport energy into the chromosphere and drive upflows (evaporation) and downflows (condensation) in the cooler, denser footpoint plasma. Observations have revealed that certain properties of the transition point between evaporation and condensation (the 'flow reversal point' or FRP), such as temperature and velocity-temperature derivative at the FRP, vary between different flares. These properties may provide a diagnostic tool to determine parameters of the coronal energy release mechanism and the loop atmosphere. In this study, we develop a one-dimensional hydrodynamical flare loop model with a simplified three-region atmosphere (chromosphere/transition region/corona), with TCFs initiated by shocks introduced in the corona. We investigate the effect of two different flare loop parameters (post-shock temperature and transition region temperature ratio) on the FRP properties. We find that both of the evaporation characteristics have scaling-law relationships to the varied flare parameters, and we report the scaling exponents for our model. This provides a means of using spectroscopic observations of the chromosphere as quantitative diagnostics of flare energy release in the corona.

  7. Evaluation of the of thermal shock resistance of a castable containing andalusite aggregates by thermal shock cycles; Avaliacao da resistencia ao dano por choque termico por ciclagem de um concreto refratario contendo agregados de andaluzita

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, G.C.R.; Santos, E.M.B.; Ribeiro, S., E-mail: girribeiro@yahoo.com.br [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia de. Departamento de Engenharia de Materiais; Resende, W.S. [Industrias Brasileiras de Artigos Refratarios (IBAR), Lorena, SP (Brazil); Rodrigues, J.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil)

    2011-07-01

    The thermal shock resistance of refractory materials is one of the most important characteristics that determine their performance in many applications, since abrupt and drastic differences in temperature can damage them. Resistance to thermal shock damage can be evaluated based on thermal cycles, i.e., successive heating and cooling cycles followed by an analysis of the drop in Young's modulus occurring in each cycle. The aim of this study was to evaluate the resistance to thermal shock damage in a commercial refractory concrete with andalusite aggregate. Concrete samples that were sintered at 1000 deg C and 1450 deg C for 5 hours to predict and were subjected to 30 thermal shock cycles, soaking in the furnace for 20 minutes at a temperature of 1000 deg C, and subsequent cooling in circulating water at 25 deg C. The results showed a decrease in Young's modulus and rupture around 72% for samples sintered at 1000 ° C, and 82% in sintered at 1450 ° C. The refractory sintered at 1450 deg C would show lower thermal shock resistance than the refractory sintered at 1000 deg C. (author)

  8. Mars Science Laboratory Rover System Thermal Test

    Science.gov (United States)

    Novak, Keith S.; Kempenaar, Joshua E.; Liu, Yuanming; Bhandari, Pradeep; Dudik, Brenda A.

    2012-01-01

    On November 26, 2011, NASA launched a large (900 kg) rover as part of the Mars Science Laboratory (MSL) mission to Mars. The MSL rover is scheduled to land on Mars on August 5, 2012. Prior to launch, the Rover was successfully operated in simulated mission extreme environments during a 16-day long Rover System Thermal Test (STT). This paper describes the MSL Rover STT, test planning, test execution, test results, thermal model correlation and flight predictions. The rover was tested in the JPL 25-Foot Diameter Space Simulator Facility at the Jet Propulsion Laboratory (JPL). The Rover operated in simulated Cruise (vacuum) and Mars Surface environments (8 Torr nitrogen gas) with mission extreme hot and cold boundary conditions. A Xenon lamp solar simulator was used to impose simulated solar loads on the rover during a bounding hot case and during a simulated Mars diurnal test case. All thermal hardware was exercised and performed nominally. The Rover Heat Rejection System, a liquid-phase fluid loop used to transport heat in and out of the electronics boxes inside the rover chassis, performed better than predicted. Steady state and transient data were collected to allow correlation of analytical thermal models. These thermal models were subsequently used to predict rover thermal performance for the MSL Gale Crater landing site. Models predict that critical hardware temperatures will be maintained within allowable flight limits over the entire 669 Sol surface mission.

  9. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.H.

    1990-03-01

    The GA-4 and GA-9 spent fuel shipping casks employ a solid neutron shielding material. During a hypothetical thermal accident, any combustion of the neutron shield must not compromise the ability of the cask to contain the radioactive contents. A two-phase thermal testing program was carried out to assist in selecting satisfactory shielding materials. In the first phase, small-scale screening tests were performed on nine candidate materials using ASTM procedures. From these initial results, three of the nine candidates were chosen for inclusion in the second phase of testing, These materials were Bisco Products NS-4-FR, Reactor Experiments 201-1, and Reactor Experiments 207. In the second phase, each selected material was fabricated into a test article which simulated a full-scale of neutron shield from the cask. The test article was heated in an environmental prescribed by NRC regulations. Results of this second testing phase showed that all three materials are thermally acceptable

  10. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.N.

    1990-01-01

    The GA-4 and GA-9 spent fuel shipping casks employ a solid neutron shielding material. During a hypothetical thermal accident, any combustion of the neutron shield must not compromise the ability of the cask to contain the radioactive contents. A two-phase thermal testing program was carried out to assist in selecting satisfactory shielding materials. In the first phase, small-scale screening tests were performed on nine candidate materials using ASTM procedures. From these initial results, three of the nine candidates were chosen for inclusion in the second phase of testing. These materials were Bisco Products NS-4-FR, Reactor Experiments 201-1, and Reactor Experiments 207. In the second phase, each selected material was fabricated into a test article which simulated a full-scale section of neutron shield from the cask. The test article was heated in an environment prescribed by NRC regulations. Results of this second testing phase show that all three materials are thermally acceptable

  11. Microstructure, Tensile Adhesion Strength and Thermal Shock Resistance of TBCs with Different Flame-Sprayed Bond Coat Materials Onto BMI Polyimide Matrix Composite

    Science.gov (United States)

    Abedi, H. R.; Salehi, M.; Shafyei, A.

    2017-10-01

    In this study, thermal barrier coatings (TBCs) composed of different bond coats (Zn, Al, Cu-8Al and Cu-6Sn) with mullite top coats were flame-sprayed and air-plasma-sprayed, respectively, onto bismaleimide matrix composites. These polyimide matrix composites are of interest to replace PMR-15, due to concerns about the toxicity of the MDA monomer from which PMR-15 is made. The results showed that pores and cracks appeared at the bond coat/substrate interface for the Al-bonded TBC because of its high thermal conductivity and diffusivity resulting in transferring of high heat flux and temperature to the polymeric substrate during top coat deposition. The other TBC systems due to the lower conductivity and diffusivity of bonding layers could decrease the adverse thermal effect on the polymer substrate during top coat deposition and exhibited adhesive bond coat/substrate interfaces. The tensile adhesion test showed that the adhesion strength of the coatings to the substrate is inversely proportional to the level of residual stress in the coatings. However, the adhesion strength of Al bond-coated sample decreased strongly after mullite top coat deposition due to thermal damage at the bond coat/substrate interface. TBC system with the Cu-6Sn bond coat exhibited the best thermal shock resistance, while Al-bonded TBC showed the lowest. It was inferred that thermal mismatch stresses and oxidation of the bond coats were the main factors causing failure in the thermal shock test.

  12. Non-thermal electron acceleration in low Mach number collisionless shocks. II. Firehose-mediated Fermi acceleration and its dependence on pre-shock conditions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xinyi; Narayan, Ramesh [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sironi, Lorenzo [NASA Einstein Postdoctoral Fellow. (United States)

    2014-12-10

    Electron acceleration to non-thermal energies is known to occur in low Mach number (M{sub s} ≲ 5) shocks in galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Using two-dimensional (2D) particle-in-cell (PIC) plasma simulations, we showed in Paper I that electrons are efficiently accelerated in low Mach number (M{sub s} = 3) quasi-perpendicular shocks via a Fermi-like process. The electrons bounce between the upstream region and the shock front, with each reflection at the shock resulting in energy gain via shock drift acceleration. The upstream scattering is provided by oblique magnetic waves that are self-generated by the electrons escaping ahead of the shock. In the present work, we employ additional 2D PIC simulations to address the nature of the upstream oblique waves. We find that the waves are generated by the shock-reflected electrons via the firehose instability, which is driven by an anisotropy in the electron velocity distribution. We systematically explore how the efficiency of wave generation and of electron acceleration depend on the magnetic field obliquity, the flow magnetization (or equivalently, the plasma beta), and the upstream electron temperature. We find that the mechanism works for shocks with high plasma beta (≳ 20) at nearly all magnetic field obliquities, and for electron temperatures in the range relevant for galaxy clusters. Our findings offer a natural solution to the conflict between the bright radio synchrotron emission observed from the outskirts of galaxy clusters and the low electron acceleration efficiency usually expected in low Mach number shocks.

  13. Shaft shock absorber tests for a spent fuel canister

    International Nuclear Information System (INIS)

    Kukkola, T.; Toermaelae, V.P.

    2005-06-01

    The disposal canister for spent nuclear fuel will be transferred by a lift to the repository, which is 500 m deep in the bedrock. Model tests were carried out with the objective to estimate weather feasible shock absorber can be developed against the design accident case where the canister should survive a free fall to the lift shaft. If the velocity of the canister is not controlled by air drag or by any other deceleration means, the impact velocity may reach ultimate speed of 100m/s. The canister would retain its integrity in impact on water when the bottom pit of the lift well is filled with groundwater. However, the canister would hit the pit bottom with high velocity since the water hardly slows down the canister. The impact to the bottom of the pit should be dampened mechanically. The tests demonstrated that 20 m high filling to the bottom pit of the lift well by Light Expanded Clay Aggregate (LECA), gives fair impact absorption to protect the fuel canister. Presence of ground water is not harmful for impact absorption system provided that the ceramic gravel is not floating too high from the pit bottom. Almost ideal impact absorption conditions are met if the water high level does not exceed two thirds of the height of the gravel. Shaping of the bottom head of the cylindrical canister does not give meaningful advantages to the impact absorption system. The flat nose bottom head of the fuel canister gives adequate deceleration properties. (orig.)

  14. Hydrogen-Helium shock Radiation tests for Saturn Entry Probes

    Science.gov (United States)

    Cruden, Brett A.

    2016-01-01

    This paper describes the measurement of shock layer radiation in Hydrogen/Helium mixtures representative of that encountered by probes entering the Saturn atmosphere. Normal shock waves are measured in Hydrogen-Helium mixtures (89:11% by volume) at freestream pressures between 13-66 Pa (0.1-0.5 Torr) and velocities from 20-30 km/s. Radiance is quantified from the Vacuum Ultraviolet through Near Infrared. An induction time of several centimeters is observed where electron density and radiance remain well below equilibrium. Radiance is observed in front of the shock layer, the characteristics of which match the expected diffusion length of Hydrogen.

  15. Large-scale thermal-shock experiments with clad and unclad steel cylinders

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1992-01-01

    Flaw behavior trends associated with pressurized-thermal-shock (PTS) loading of pressurized-water-reactor pressure vessels have been under investigation at the Oak Ridge National Laboratory for nearly 20 years. During that time, twelve thermal-shock experiments with thick-walled (152 mm) steel cylinders were conducted as a part of the investigations. The first eight experiments were conducted with unclad cylinders initially containing shallow (8--19 mm) two-dimensional and semicircular inner-surface flaws. These experiments demonstrated, in good agreement with linear elastic fracture mechanics, crack initiation and arrest, a series of initiation/arrest events with deep penetration of the wall, long crack jumps, arrest with the stress intensity factor (K I ) increasing with crack depth, extensive surface extension of an initially short and shallow (semicircular) flaw, and warm prestressing with K I ≤ 0. The remaining four experiments were conducted with clad cylinders containing initially shallow (19--24 mm) semielliptical subclad and surface flaws at the inner surface. In the first of these experiments one of six equally spaced (60 degrees) open-quotes identicalclose quotes subclad flaws extended nearly the length of the cylinder (1,220 mm) beneath the cladding (no crack extension into the cladding) and nearly 50% of the wall, radially. For the final experiment, four of the semielliptical subclad flaws that had not propagated previously were converted to surface flaws, and they experienced extensive extension beneath the cladding with no cracking of the cladding. Information from this series of thermal-shock experiments is being used in the evaluation of the PTS issue

  16. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800 degree C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280 degree F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found

  17. A fracture mechanics method of evaluating structural integrity of a reactor vessel due to thermal shock effects following LOCA condition

    International Nuclear Information System (INIS)

    Ramani, D.T.

    1977-01-01

    The importance of knowledge of structural integrity of a reactor vessel due to thermal shock effects, is related to safety and operational requirements in assessing the adequacy and flawless functioing of the nuclear power systems. Followig a loss-of-coolant accident (LOCA) condition the integrity of the reactor vessel due to a sudden thermal shock induced by actuation of emergency core cooling system (ECCS), must be maintained to ensure safe and orderly shutdown of the reactor and its components. The paper encompasses criteria underlaying a fracture mechanics method of analysis to evaluate structural integrity of a typical 950 MWe PWR vessel as a result of very drastic changes in thermal and mechanical stress levels in the reactor vessel wall. The main object of this investigation therefore consists in assessing the capability of a PWR vessel to withstand the most critical thermal shock without inpairing its ability to conserve vital coolant owing to probable crack propagation. (Auth.)

  18. Stochastic simulation of PWR vessel integrity for pressurized thermal shock conditions

    International Nuclear Information System (INIS)

    Jackson, P.S.; Moelling, D.S.

    1984-01-01

    A stochastic simulation methodology is presented for performing probabilistic analyses of Pressurized Water Reactor vessel integrity. Application of the methodology to vessel-specific integrity analyses is described in the context of Pressurized Thermal Shock (PTS) conditions. A Bayesian method is described for developing vessel-specific models of the density of undetected volumetric flaws from ultrasonic inservice inspection results. Uncertainty limits on the probabilistic results due to sampling errors are determined from the results of the stochastic simulation. An example is provided to illustrate the methodology

  19. WSEAT Shock Testing Margin Assessment Using Energy Spectra Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Sisemore, Carl; Babuska, Vit; Booher, Jason

    2018-02-01

    Several programs at Sandia National Laboratories have adopted energy spectra as a metric to relate the severity of mechanical insults to structural capacity. The purpose being to gain insight into the system's capability, reliability, and to quantify the ultimate margin between the normal operating envelope and the likely system failure point -- a system margin assessment. The fundamental concern with the use of energy metrics was that the applicability domain and implementation details were not completely defined for many problems of interest. The goal of this WSEAT project was to examine that domain of applicability and work out the necessary implementation details. The goal of this project was to provide experimental validation for the energy spectra based methods in the context of margin assessment as they relate to shock environments. The extensive test results concluded that failure predictions using energy methods did not agree with failure predictions using S-N data. As a result, a modification to the energy methods was developed following the form of Basquin's equation to incorporate the power law exponent for fatigue damage. This update to the energy-based framework brings the energy based metrics into agreement with experimental data and historical S-N data.

  20. Survey of solar thermal test facilities

    Energy Technology Data Exchange (ETDEWEB)

    Masterson, K.

    1979-08-01

    The facilities that are presently available for testing solar thermal energy collection and conversion systems are briefly described. Facilities that are known to meet ASHRAE standard 93-77 for testing flat-plate collectors are listed. The DOE programs and test needs for distributed concentrating collectors are identified. Existing and planned facilities that meet these needs are described and continued support for most of them is recommended. The needs and facilities that are suitable for testing components of central receiver systems, several of which are located overseas, are identified. The central contact point for obtaining additional details and test procedures for these facilities is the Solar Thermal Test Facilities Users' Association in Albuquerque, N.M. The appendices contain data sheets and tables which give additional details on the technical capabilities of each facility. Also included is the 1975 Aerospace Corporation report on test facilities that is frequently referenced in the present work.

  1. Advanced Testing Method for Ground Thermal Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaobing [ORNL; Clemenzi, Rick [Geothermal Design Center Inc.; Liu, Su [University of Tennessee (UT)

    2017-04-01

    A new method is developed that can quickly and more accurately determine the effective ground thermal conductivity (GTC) based on thermal response test (TRT) results. Ground thermal conductivity is an important parameter for sizing ground heat exchangers (GHEXs) used by geothermal heat pump systems. The conventional GTC test method usually requires a TRT for 48 hours with a very stable electric power supply throughout the entire test. In contrast, the new method reduces the required test time by 40%–60% or more, and it can determine GTC even with an unstable or intermittent power supply. Consequently, it can significantly reduce the cost of GTC testing and increase its use, which will enable optimal design of geothermal heat pump systems. Further, this new method provides more information about the thermal properties of the GHEX and the ground than previous techniques. It can verify the installation quality of GHEXs and has the potential, if developed, to characterize the heterogeneous thermal properties of the ground formation surrounding the GHEXs.

  2. Drop Hammer Tests with Three Oleo Strut Models and Three Different Shock Strut Oils at Low Temperatures

    Science.gov (United States)

    Kranz, M

    1954-01-01

    Drop hammer tests with different shock strut models and shock strut oils were performed at temperatures ranging to -40 C. The various shock strut models do not differ essentially regarding their springing and damping properties at low temperatures; however, the influence of the different shock strut oils on the springing properties at low temperatures varies greatly.

  3. Advanced Spectroscopic and Thermal Imaging Instrumentation for Shock Tube and Ballistic Range Facilities

    Science.gov (United States)

    Grinstead, Jay H.; Wilder, Michael C.; Reda, Daniel C.; Cruden, Brett A.; Bogdanoff, David W.

    2010-01-01

    The Electric Arc Shock Tube (EAST) facility and Hypervelocity Free Flight Aerodynamic Facility (HFFAF, an aeroballistic range) at NASA Ames support basic research in aerothermodynamic phenomena of atmospheric entry, specifically shock layer radiation spectroscopy, convective and radiative heat transfer, and transition to turbulence. Innovative optical instrumentation has been developed and implemented to meet the challenges posed from obtaining such data in these impulse facilities. Spatially and spectrally resolved measurements of absolute radiance of a travelling shock wave in EAST are acquired using multiplexed, time-gated imaging spectrographs. Nearly complete spectral coverage from the vacuum ultraviolet to the near infrared is possible in a single experiment. Time-gated thermal imaging of ballistic range models in flight enables quantitative, global measurements of surface temperature. These images can be interpreted to determine convective heat transfer rates and reveal transition to turbulence due to isolated and distributed surface roughness at hypersonic velocities. The focus of this paper is a detailed description of the optical instrumentation currently in use in the EAST and HFFAF.

  4. Potential effect of fracture technology on IPTS [Integrated Pressurized Thermal Shock] analysis (Fracture toughness: Kla and Klc and warm prestressing)

    International Nuclear Information System (INIS)

    Dickson, T.L.

    1990-01-01

    A major nuclear plant life extension issue to be confronted in the 1990's is pressure vessel integrity for the pressurized thermal shock (PTS) loading condition. Governing criteria associated with PTS are included in ''The PTS Rule'' (10 CFR 50.61) and Regulatory Guide 1.154: Format and Content of Plant-Specific Pressurized Thermal Shock Safety Analysis Reports for Pressurized Water Reactors. The results of the Integrated Pressurized Water Reactors. The results of the Integrated Pressurized Thermal Shock (IPTS) Program, along with risk assessments and fracture analyses performed by the NRC and reactor system vendors, contributed to the derivation of the PTS Rule. Over the last several years, the Heavy Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory (ORNL) has performed a series of large-scale fracture-mechanics experiments. The Thermal Shock Experiments (TSE), Pressurized Thermal Shock Experiments (PTSE), and Wide Plate Experiments (WPE) produced K IC and K Ia data that suggest increased mean K IC and K Ia curves relative to the ones used in the IPTS study. Also, the PTSE and WPE have demonstrated that prototypical nuclear reactor pressure vessel steels are capable of arresting a propagating crack at K I values considerably above 220 MPa√m, the implicit limit of the ASME Code and the limit used in the IPTS studies. This document provides a discussion of the results of these experiments

  5. Thermal testing of solid neutron shielding materials

    International Nuclear Information System (INIS)

    Boonstra, R.H.

    1993-01-01

    In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-A19897, R.H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280degF. Table 1 lists the neutron shield materials tested. The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found. The Bisco modified NS-4 and Reactor Experiments HMPP are both acceptable materials from a thermal accident standpoint for use in the shipping cask. Tests of the Kobe PP-R01 and Envirotech HDPE were stopped for safety reasons, due to inability to deal with the heavy smoke, before completion of the 30-minute heating phase. However these materials may prove satisfactory if they could undergo the complete heating. (J.P.N.)

  6. Shaft shock absorber tests for a spent fuel canister

    International Nuclear Information System (INIS)

    Kukkola, T.; Toermaelae, V.P.

    2003-01-01

    The holding canister for spent nuclear fuel will be transferred by a lift to the final disposal tunnels 500m deep in the bedrock. Model tests were carried out with an objective to estimate weather feasible shock absorbing properties can be met in a design accident case where the canister should survive a free fall due to e.g. sabotage. If the velocity of the canister is not controlled by air drag or any other deceleration means, the impact velocity may reach ultimate speed of 100m/s. The canister would retain its integrity when stricken by the surface penetration impact if the bottom pit of the lift well would be filled with groundwater. However the canister would hit the pit bottom with high velocity since the water hardly slows down the canister. The impact to the bottom of the pit should be dampened mechanically. The tests demonstrated that 20m high filling to the bottom pit of the lift well by ceramic gravel, trade mark LECA-sora, gives a fair impact absorption to protect the spent fuel canister. Presence of ground water is not harmful for impact absorption system provided that the ceramic gravel is not floating too high from the pit bottom. Almost ideal impact absorption conditions are met if the water high level does not exceed two thirds of the height of the gravel. Shaping of the bottom head of the cylindrical canister does not give meaningful advantages to the impact absorption system. The flat nose bottom head of the fuel canister gives adequate deceleration properties. (orig.)

  7. Thermal shock induced dynamics of a spacecraft with a flexible deploying boom

    Science.gov (United States)

    Shen, Zhenxing; Li, Huijian; Liu, Xiaoning; Hu, Gengkai

    2017-12-01

    The dynamics in the process of deployment of a flexible extendible boom as a deployable structure on the spacecraft is studied. For determining the thermally induced vibrations of the boom subjected to an incident solar heat flux, an axially moving thermal-dynamic beam element based on the absolute nodal coordinate formulation which is able to precisely describe the large displacement, rotation and deformation of flexible body is presented. For the elastic forces formulation of variable-length beam element, the enhanced continuum mechanics approach is adopted, which can eliminate the Poisson locking effect, and take into account the tension-bending-torsion coupling deformations. The main body of the spacecraft, modeled as a rigid body, is described using the natural coordinates method. In the derived nonlinear thermal-dynamic equations of rigid-flexible multibody system, the mass matrix is time-variant, and a pseudo damping matrix which is without actual energy dissipation, and a heat conduction matrix which is relative to the moving speed and the number of beam element are arisen. Numerical results give the dynamic and thermal responses of the nonrotating and spinning spacecraft, respectively, and show that thermal shock has a significant influence on the dynamics of spacecraft.

  8. Behaviour of Ti-doped CFCs under thermal fatigue tests

    Energy Technology Data Exchange (ETDEWEB)

    Centeno, A. [Instituto Nacional del Carbon (CSIC), Apdo. 73, 33080 Oviedo (Spain); Pintsuk, G.; Linke, J. [Forschungszentrum Juelich GmbH, EURATOM Association, 52425 Juelich (Germany); Gualco, C. [Ansaldo Energia, I-16152 Genoa (Italy); Blanco, C., E-mail: clara@incar.csic.es [Instituto Nacional del Carbon (CSIC), Apdo. 73, 33080 Oviedo (Spain); Santamaria, R.; Granda, M.; Menendez, R. [Instituto Nacional del Carbon (CSIC), Apdo. 73, 33080 Oviedo (Spain)

    2011-01-15

    In spite of the remarkable progress in the design of in-vessel components for the divertor of the first International Thermonuclear Experimental Reactor (ITER), a great effort is still put into the development of manufacturing technologies for carbon armour with improved properties. Newly developed 3D titanium-doped carbon fibre reinforced composites and their corresponding undoped counterparts were brazed to a CuCrZr heat sink to produce actively cooled flat tile mock-ups. By exposing the mock-ups to thermal fatigue tests in an electron beam test facility, the material behaviour and the brazing between the individual constituents in the mock-up was qualified. The mock-ups with titanium-doped CFCs exhibited a significantly improved thermal fatigue resistance compared with those undoped materials. The comparison of these mock-ups with those produced using pristine NB31, one of the reference materials as plasma facing material for ITER, showed almost identical results, indicating the high potential of Ti-doped CFCs due to their improved thermal shock resistance.

  9. Thermal test requirements and their verification by different test methods

    International Nuclear Information System (INIS)

    Droste, B.; Wieser, G.; Probst, U.

    1993-01-01

    The paper discusses the parameters influencing the thermal test conditions for type B-packages. Criteria for different test methods (by analytical as well as by experimental means) will be developed. A comparison of experimental results from fuel oil pool and LPG fire tests will be given. (J.P.N.)

  10. Analysis of Reactor Pressurized Thermal Shock Conditions Considering Upgrading of Systems Important to Safety

    International Nuclear Information System (INIS)

    Mazurok, A.S; Vyshemirskyij, M.P.

    2015-01-01

    The paper analyzes conditions of pressurized thermal shock on the reactor pressure vessel taking into account upgrading of the emergency core cooling system and primary overpressure protection system. For representative accident scenarios, calculation and comparative analysis was carried out. These scenarios include a small leak from the hot leg and PRZ SV stuck opening with re closure after 3600 sec and 3 SG heat transfer tube rupture. The efficiency of mass flow control by valves on the pump head (emergency core cooling systems) and cold overpressure protection (primary overpressure protection system) was analyzed. The thermal hydraulic model for RELAP5/Mod3.2 code with detailed downcomer (DC) model and changes in accordance with upgrades was used for calculations. Detailed (realistic) modeling of piping and equipment was performed. The upgrades prevent excessive primary cooling and, consequently, help to preserve the RPV integrity and to avoid the formation of a through crack, which can lead to a severe accident

  11. RETRAN applications in pressurized thermal shock analysis of turkey point units 3 and 4

    International Nuclear Information System (INIS)

    Arpa, J.; Fatemi, A.S.; Mathavan, S.K.

    1985-01-01

    A methodology to assess the impact of overcooling transients on vessel wall integrity with respect to pressurized thermal shock conditions has been developed at Florida Power and Light Company for the Turkey Point Nuclear Units. Small break loss-of-coolant and small steamline break events have been simulated with the RETRAN code. Highly conservative assumptions, such as engineered safeguards with minimum temperature and maximum flow, have been made to maximize cooldown and thermal stress in the vessel wall. Temperatures, pressures, and flows obtained with RETRAN provide input for stress and fracture mechanics analyses that evaluate reactor vessel integrity. The results of the RETRAN analyses compare well with generic calculations performed by the Westinghouse Owners Group for a similar type of plant

  12. Pressurized thermal shock probabilistic fracture mechanics sensitivity analysis for Yankee Rowe reactor pressure vessel

    International Nuclear Information System (INIS)

    Dickson, T.L.; Cheverton, R.D.; Bryson, J.W.; Bass, B.R.; Shum, D.K.M.; Keeney, J.A.

    1993-08-01

    The Nuclear Regulatory Commission (NRC) requested Oak Ridge National Laboratory (ORNL) to perform a pressurized-thermal-shock (PTS) probabilistic fracture mechanics (PFM) sensitivity analysis for the Yankee Rowe reactor pressure vessel, for the fluences corresponding to the end of operating cycle 22, using a specific small-break-loss- of-coolant transient as the loading condition. Regions of the vessel with distinguishing features were to be treated individually -- upper axial weld, lower axial weld, circumferential weld, upper plate spot welds, upper plate regions between the spot welds, lower plate spot welds, and the lower plate regions between the spot welds. The fracture analysis methods used in the analysis of through-clad surface flaws were those contained in the established OCA-P computer code, which was developed during the Integrated Pressurized Thermal Shock (IPTS) Program. The NRC request specified that the OCA-P code be enhanced for this study to also calculate the conditional probabilities of failure for subclad flaws and embedded flaws. The results of this sensitivity analysis provide the NRC with (1) data that could be used to assess the relative influence of a number of key input parameters in the Yankee Rowe PTS analysis and (2) data that can be used for readily determining the probability of vessel failure once a more accurate indication of vessel embrittlement becomes available. This report is designated as HSST report No. 117

  13. Elastic-plastic Fracture Mechanics Assessment of nozzle corners submitted to thermal shock loading

    International Nuclear Information System (INIS)

    Chapuliot, S.; Marie, S.

    2016-01-01

    This paper focuses on the development of a simplified analytical scheme for the elastic-plastic Fracture Mechanics Assessment of large nozzle corners. Within that frame, following the specific numerical effort performed for the definition of a Stress Intensity Factor compendium, complementary elastic-plastic developments are proposed here for the consideration of the thermal shock loading in the elastic-plastic domain: this type of loading is a major loading for massive structures such as nozzle corners of large components. Thus, an important numerical was performed in order to extend the applicability domain of existing analytical schemes to those complex geometries. The final formulation is a simple one, applicable to a large variety of materials and geometrical configurations as long as the structure is large and the defect remains small in comparison to the internal radius of the nozzle. - Highlights: • Fracture Mechanics Assessment of large nozzle corners. • Elastic-plastic Stress Intensity Factor determination under thermal shock loading. • Semi-analytical schemes for J calculation.

  14. Effects of heat transfer coefficient treatments on thermal shock fracture prediction for LWR fuel claddings in water quenching

    International Nuclear Information System (INIS)

    Lee, Youho; Lee, Jeong Ik; Cheon, Hee

    2015-01-01

    Accurate modeling of thermal shock induced stresses has become ever most important to emerging accident-tolerant ceramic cladding concepts, such as silicon carbide (SiC) and SiC coated zircaloy. Since fractures of ceramic (entirely ceramic or coated) occur by excessive tensile stresses with linear elasticity, modeling transient stress distribution in the material provides a direct indication of the structural integrity. Indeed, even for the current zircaloy cladding material, the oxide layer formed on the surface - where cracks starts to develop upon water quenching - essentially behaves as a brittle ceramic. Hence, enhanced understanding of thermal shock fracture of a brittle material would fundamentally contribute to safety of nuclear reactors for both the current fuel design and that of the coming future. Understanding thermal shock fracture of a brittle material requires heat transfer rate between the solid and the fluid for transient temperature fields of the solid, and structural response of the solid under the obtained transient temperature fields. In water quenching, a solid experiences dynamic time-varying heat transfer rates with phase changes of the fluid over a short quenching period. Yet, such a dynamic change of heat transfer rates during the water quenching transience has been overlooked in assessments of mechanisms, predictability, and uncertainties for thermal shock fracture. Rather, a time-constant heat transfer coefficient, named 'effective heat transfer coefficient' has become a conventional input to thermal shock fracture analysis. No single constant heat transfer could suffice to depict the actual stress evolution subject to dynamic heat transfer coefficient changes with fluid phase changes. Use of the surface temperature dependent heat transfer coefficient will remarkably increase predictability of thermal shock fracture of brittle materials and complete the picture of stress evolution in the quenched solid. The presented result

  15. Fracture-mechanics data deduced from thermal-shock and related experiments with LWR pressure-vessel material

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Canonico, D.A.; Iskander, S.K.; Bolt, S.E.; Holz, P.P.; Nanstad, R.K.; Stelzman, W.J.

    1982-01-01

    Pressurized water reactors (PWRs) are susceptible to certain types of hypothetical accidents that can subject the reactor pressure vessel to severe thermal shock, that is, a rapid cooling of the inner surface of the vessel wall. The thermal-shock loading, coupled with the radiation-induced reduction in the material fracture toughness, introduces the possibility of propagation of preexistent flaws and what at one time were regarded as somewhat unique fracture-oriented conditions. Several postulated reactor accidents have been analyzed to discover flaw behavior trends; seven intermediate-scale thermal-shock experiments with steel cylinders have been conducted; and corresponding materials characterization studies have been performed. Flaw behavior trends and related fracture-mechanics data deduced from these studies are discussed

  16. Effects of heat transfer coefficient treatments on thermal shock fracture prediction for LWR fuel claddings in water quenching

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho; Lee, Jeong Ik; Cheon, Hee [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Accurate modeling of thermal shock induced stresses has become ever most important to emerging accident-tolerant ceramic cladding concepts, such as silicon carbide (SiC) and SiC coated zircaloy. Since fractures of ceramic (entirely ceramic or coated) occur by excessive tensile stresses with linear elasticity, modeling transient stress distribution in the material provides a direct indication of the structural integrity. Indeed, even for the current zircaloy cladding material, the oxide layer formed on the surface - where cracks starts to develop upon water quenching - essentially behaves as a brittle ceramic. Hence, enhanced understanding of thermal shock fracture of a brittle material would fundamentally contribute to safety of nuclear reactors for both the current fuel design and that of the coming future. Understanding thermal shock fracture of a brittle material requires heat transfer rate between the solid and the fluid for transient temperature fields of the solid, and structural response of the solid under the obtained transient temperature fields. In water quenching, a solid experiences dynamic time-varying heat transfer rates with phase changes of the fluid over a short quenching period. Yet, such a dynamic change of heat transfer rates during the water quenching transience has been overlooked in assessments of mechanisms, predictability, and uncertainties for thermal shock fracture. Rather, a time-constant heat transfer coefficient, named 'effective heat transfer coefficient' has become a conventional input to thermal shock fracture analysis. No single constant heat transfer could suffice to depict the actual stress evolution subject to dynamic heat transfer coefficient changes with fluid phase changes. Use of the surface temperature dependent heat transfer coefficient will remarkably increase predictability of thermal shock fracture of brittle materials and complete the picture of stress evolution in the quenched solid. The presented result

  17. Electrostatic Assembly Preparation of High-Toughness Zirconium Diboride-Based Ceramic Composites with Enhanced Thermal Shock Resistance Performance.

    Science.gov (United States)

    Zhang, Baoxi; Zhang, Xinghong; Hong, Changqing; Qiu, Yunfeng; Zhang, Jia; Han, Jiecai; Hu, PingAn

    2016-05-11

    The central problem of using ceramic as a structural material is its brittleness, which associated with rigid covalent or ionic bonds. Whiskers or fibers of strong ceramics such as silicon carbide (SiC) or silicon nitride (Si3N4) are widely embedded in a ceramic matrix to improve the strength and toughness. The incorporation of these insulating fillers can impede the thermal flow in ceramic matrix, thus decrease its thermal shock resistance that is required in some practical applications. Here we demonstrate that the toughness and thermal shock resistance of zirconium diboride (ZrB2)/SiC composites can be improved simultaneously by introducing graphene into composites via electrostatic assembly and subsequent sintering treatment. The incorporated graphene creates weak interfaces of grain boundaries (GBs) and optimal thermal conductance paths inside composites. In comparison to pristine ZrB2-SiC composites, the toughness of (2.0%) ZrB2-SiC/graphene composites exhibited a 61% increasing (from 4.3 to 6.93 MPa·m(1/2)) after spark plasma sintering (SPS); the retained strength after thermal shock increased as high as 74.8% at 400 °C and 304.4% at 500 °C. Present work presents an important guideline for producing high-toughness ceramic-based composites with enhanced thermal shock properties.

  18. In-situ thermal testing program strategy

    International Nuclear Information System (INIS)

    1995-06-01

    In the past year the Yucca Mountain Site Characterization Project has implemented a new Program Approach to the licensing process. The Program Approach suggests a step-wise approach to licensing in which the early phases will require less site information than previously planned and necessitate a lesser degree of confidence in the longer-term performance of the repository. Under the Program Approach, the thermal test program is divided into two principal phases: (1) short-term in situ tests (in the 1996 to 2000 time period) and laboratory thermal tests to obtain preclosure information, parameters, and data along with bounding information for postclosure performance; and (2) longer-term in situ tests to obtain additional data regarding postclosure performance. This effort necessitates a rethinking of the testing program because the amount of information needed for the initial licensing phase is less than previously planned. This document proposes a revised and consolidated in situ thermal test program (including supporting laboratory tests) that is structured to meet the needs of the Program Approach. A customer-supplier model is used to define the Project data needs. These data needs, along with other requirements, were then used to define a set of conceptual experiments that will provide the required data within the constraints of the Program Approach schedule. The conceptual thermal tests presented in this document represent a consolidation and update of previously defined tests that should result in a more efficient use of Project resources. This document focuses on defining the requirements and tests needed to satisfy the goal of a successful license application in 2001, should the site be found suitable

  19. Context-dependent effects of hippocampal damage on memory in the shock-probe test.

    Science.gov (United States)

    Lehmann, Hugo; Carfagnini, Adrienne; Yamin, Stephanie; Mumby, Dave G

    2005-01-01

    We assessed the role of the hippocampus in anterograde memory, using the shock-probe test. Rats with sham or neurotoxic lesions of the hippocampus were given a shock-probe acquisition session during which each time they contacted a probe they received a shock; 24 h later, the rats were given a second shock-probe session to test their retention, but in this instance the probe was not electrified. Rats were tested in either the same context as the one used during acquisition or in a different context. The hippocampal lesions impaired avoidance of the probe and burying on the retention test, suggesting that the lesions induced anterograde amnesia. However, the impairment was context dependent. The hippocampal lesions impaired avoidance only when the rats were tested in the context in which they received the conditioning. The results of the shock-probe test suggest that the anterograde amnesia following hippocampal lesions is due mainly to an inability to associate the context with the shock more than to an inability to associate the probe with shock. Copyright (c) 2004 Wiley-Liss, Inc.

  20. Rippled shock front solutions for testing hydrodynamic stability simulations

    International Nuclear Information System (INIS)

    Munro, D.H.

    1989-01-01

    The response of a shock front to arbitrary small perturbations can be calculated analytically. Such rippled shock front solutions are useful for determining the accuracy of hydrodynamic simulation codes such as LASNEX [Comments Plasma Phys. Controlled Fusion 2, 51 (1977)], which are used to compute perturbation growth in inertial fusion targets. The LASNEX fractional errors are of order κ 2 L 2 , where κ is the transverse wavenumber of the perturbation, and L is the largest zone dimension. Numerical errors are about 25% for a calculation using 26 zones per transverse wavelength

  1. Probabilistic fracture mechanics analysis of reactor vessel for pressurized thermal shock: the effect of residual stress and fracture toughness

    International Nuclear Information System (INIS)

    Jung, Sung Gyu; Jin, Tae Eun; Jhung, Myung Jo; Choi, Young Hwan

    2003-01-01

    The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated

  2. Noncoplanar magnetic fields at collisionless shocks: A test of a new approach

    International Nuclear Information System (INIS)

    Gosling, J.T.; Winske, D.; Thomsen, M.F.

    1988-01-01

    Within the foot and ramp of a fast mode collisionless shock the magnetic field rotates out of the plane of coplanarity defined by the upstream magnetic field and the shock normal. As previously noted (Goodrich and Scudder, 1984), the sense of this rotation is such as to reduce the cross-shock potential drop when measured in the deHoffman-Teller frame relative to that measured in the normal incidence frame. From a consideration of the requirement that there be zero current in the coplanarity plane downstream of the shock, Jones and Ellison (1987) have argued that the field rotation and potential drop difference are a consequence of unequal ion and electron masses, and have derived an expression for the spatial integral of the noncoplanar field component in terms of the electron current within the shock layer. Moreover, by assuming that the ion current within the shock layer is negligible compared to the electron current, they derive equations which predict the magnitude of both the field rotation and the potential drop difference in terms of upstream quantities and the field jump at the shock. We have tested their equations with ISEE 1 and 2 plasma and field measurements at the Earth's bow shock and by means of numerical simulations. We find substantial support for their suggestion that the field rotation and thus also the frame dependence of the potential drop are fundamentally a consequence of unequal ion and electron masses. Further, for subcritical shocks (low Mach number) one can neglect the ion current to predict both the sign and the magnitude of the field rotation and potential drop difference. However, at supercritical shocks (high Mach numbers) the ion current associated with reflected, gyrating ions cannot be neglected, and the final equations of Jones and Ellison seriously underestimate the magnitude of the field rotation and the potential drop difference at these shocks

  3. Low carbon content and carbon-free refractory materials with high thermal shock resistance; Thermoschockbestaendige feuerfeste Erzeugnisse mit geringerem Kohlenstoffgehalt bzw. kohlenstofffreie Erzeugnisse

    Energy Technology Data Exchange (ETDEWEB)

    Brachhold, Nora; Aneziris, C.G.; Stein, Volker; Roungos, Vasileios; Moritz, Kirsten [TU Bergakademie Freiberg (TUBAF) (DE). Inst. fuer Keramik, Glas- und Baustofftechnik (IKGB)

    2012-07-01

    Carbon bonded refractories are essential for steelmaking due to their excellent thermal shock resistance. The research on carbon reduced and carbon-free materials is necessary to manufacture high quality stainless steels tending carbon pick-up in contact to conventional refractory materials. Further advantages are reduced emissions of CO{sub 2} and energy saving potentials due to better heat insulation properties. The challenge is to develop alternative materials with lower carbon contents but with the necessary thermal shock resistance. The Priority Programme 1418 funded by the German Research Foundation (DFG) concentrates on this problem. In this article two materials are presented. First, the carbon content could be reduced by nanoscaled additives resulting in better bonding between matrix and oxidic components. Second, an AL{sub 2}O{sub 3}-rich carbon-free material is presented showing a very good thermal shock resistance due to its designed microstructure. Finally, a steel casting simulator is introduced to test the new materials under nearly real conditions. (orig.)

  4. Development and Realization of a Shock Wave Test on Expert Flap Qualification Model

    Science.gov (United States)

    De Fruytier, C.; Dell'Orco, F.; Ullio, R.; Gomiero, F.

    2012-07-01

    This paper presents the methodology and the results of the shock test campaign conducted by TAS-I and TAS ETCA to qualify the EXPERT Flap in regards of shock wave and acoustic load generated by pyrocord detonation at stages 2/3 separation phase of the EXPERT vehicle. The design concept of the open flap (manufactured by MT AEROSPACE) is a fully integral manufactured, four sided control surface, with an additional stiffening rib and flanges to meet the first eigenfrequency and the allowable deformation requirement with a minimum necessary mass. The objectives were to reproduce equivalent loading at test article level in terms of pulse duration, front pressure, front velocity and acoustic emission. The Thales Alenia Space ETCA pyrotechnic shock test device is usually used to produce high level shocks by performing a shock on a test fixture supporting the unit under test. In this case, the facility has been used to produce a shock wave, with different requested physical characteristics, directed to the unit under test. Different configurations have been tried on a dummy of the unit to test, following an empirical process. This unusual work has lead to the definition of a nominal set- up meeting the requested physical parameters. Two blast sensors have been placed to acquire the pressure around the flap. The distance between the two sensors has allowed estimating the front pressure velocity. Then, several locations have been selected to acquire the acceleration responses on the unit when it was submitted to this environment. Additionally, a “standard” shock test has been performed on this model. The qualification of the flap, in regards of shock environment, has been successfully conducted.

  5. Shallow crack effect on brittle fracture of RPV during pressurised thermal shock

    International Nuclear Information System (INIS)

    Ikonen, K.

    1995-12-01

    This report describes the study on behaviour of postulated shallow surface cracks in embrittled reactor pressure vessel subjected to pressurised thermal shock loading in an emergency core cooling. The study is related to the pressure vessel of a VVER-440 type reactor. Instead of a conventional fracture parameter like stress intensity factor or J integral the maximum principal stress distribution on a crack tip area is used as a fracture criteria. The postulated cracks locate circumferentially at the inner surface of the reactor pressure wall and they penetrate the cladding layer and open to the inner surface. Axisymmetric and semielliptical crack shapes were studied. Load is formed of an internal pressure acting also on crack faces and of a thermal gradient in the pressure vessel wall. Physical properties of material and loading data correspond real conditions in VVER-440 RPV. The study was carried out by making lot of 2D- and 3D- finite element calculations. Analysing principles and computer programs are explained. Except of studying the shallow crack effect, one objective of the study has also been to develop further expertise and the in-house developed computing system to make effectively elastic-plastic fracture mechanical analyses for real structures under complicated loads. Though the study concerns VVER-440 RPV, the results are of more general interest especially related to thermal loads. (orig.) (11 refs.)

  6. FAVOR: A new fracture mechanics code for reactor pressure vessels subjected to pressurized thermal shock

    International Nuclear Information System (INIS)

    Dickson, T.L.

    1993-01-01

    This report discusses probabilistic fracture mechanics (PFM) analysis which is a major element of the comprehensive probabilistic methodology endorsed by the NRC for evaluation of the integrity of Pressurized Water Reactor (PWR) pressure vessels subjected to pressurized-thermal-shock (PTS) transients. It is anticipated that there will be an increasing need for an improved and validated PTS PFM code which is accepted by the NRC and utilities, as more plants approach the PTS screening criteria and are required to perform plant-specific analyses. The NRC funded Heavy Section Steel Technology (HSST) Program at Oak Ridge National Laboratories is currently developing the FAVOR (Fracture Analysis of Vessels: Oak Ridge) PTS PFM code, which is intended to meet this need. The FAVOR code incorporates the most important features of both OCA-P and VISA-II and contains some new capabilities such as PFM global modeling methodology, the capability to approximate the effects of thermal streaming on circumferential flaws located inside a plume region created by fluid and thermal stratification, a library of stress intensity factor influence coefficients, generated by the NQA-1 certified ABAQUS computer code, for an adequate range of two and three dimensional inside surface flaws, the flexibility to generate a variety of output reports, and user friendliness

  7. High shock load testing of lithium-thionyl chloride batteries

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, J.; Marincic, N.

    1983-10-01

    Low rate cylindrical cells have been developed, capable of withstanding mechanical shocks up to 23,000 g's for one millisecond. The cells were based on the lithium-thionyl chloride battery system and totally hermetic stainless steel hardware incorporating a glass sealed positive terminal. Four cells in series were required to deliver 25 mA pulses at a minimum voltage of 10 V before and after such exposure to one mechanical shock. Batteries were contained in a hardened steel housing and mounted within a projectile accelerated by means of a gas gun. The velocity of the projectile was measured with electronic probes immediately before impact and the deceleration was effected using a special aluminum honeycomb structure from which the g values were calculated. A high survival rate for the cells was achieved in spite of some mechanical damage to the battery housing still present.

  8. Pressurized thermal shock evaluation of the Calvert Cliffs Unit 1 Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, L [ed.

    1985-09-01

    An evaluation of the risk to the Calvert Cliffs Unit 1 nuclear power plant due to pressurized thermal shock (PTS) has been completed by Oak Ridge National Laboratory (ORNL) with the assistance of several other organizations. This evaluation was part of a Nuclear Regulatory Commission program designed to study the PTS risk to three nuclear plants, the other two plants being Oconee Unit 1 and H.B. Robinson Unit 2. The specific objectives of the program were to (1) provide a best estimate of the frequency of a through-the-wall crack in the pressure vessel at each of the three plants, together with the uncertainty in the estimated frequency and its sensitivity to the variables used in the evaluation; (2) determine the dominant overcooling sequences contributing to the estimated frequency and the associated failures in the plant systems or in operator actions; and (3) evaluate the effectiveness of potential corrective measures.

  9. Effects of low upper shelf fracture toughness on reactor vessel integrity during pressurized thermal shock events

    International Nuclear Information System (INIS)

    Bamford, W.H.; Heinecke, C.C.; Balkey, K.R.

    1988-01-01

    For the past decade, significant attention has been focused on the subject of nuclear rector vessel integrity during pressurized thermal shock (PTS) events. The issue of low upper shelf fracture toughness at operating temperatures has been a consideration for some reactor vessel materials since the early 1970's. Deterministic and probabilistic fracture mechanics sensitivity studies have been completed to evaluate the interaction between the PTS and lower upper shelf toughness issues that result from neutron embrittlement of the critical beltline region materials. This paper presents the results of these studies to show the interdependency of these fracture considerations in certain instances and to identify parameters that need to be carefully treated in reactor vessel integrity evaluations for these subjects. This issue is of great importance to those vessels which have low upper shelf toughness, both for demonstrating safety during the original design life and in life extension assessments

  10. Analysis of crack behavior in the JRC Ispra pressurized thermal shock experiment

    International Nuclear Information System (INIS)

    Jovanovic, A.; Lucia, A.C.

    1990-01-01

    The analytical work performed in the framework of the Pressurized Thermal Shock (PTS) experimental research at the JRC Ispra, Italy, is described in the paper. In particular, the development of the FRAP preprocessor and development and implementation of a methodology for analysis of local non-stationary heat transfer coefficients during a PTS, have been tackled. FRAP is used as a front-end for the finite element code ABAQUS, for the heat transfer, stress and fracture mechanics analyses. The ABAQUS results are used further on, for the probabilistic fatigue crack analysis performed by the JRC Ispra code COVASTOL. Only the preliminary results of application of FRAP, ABAQUS and COVASTOL codes in the experiment are given in this paper, in order to illustrate the applied analytical procedure. (orig.)

  11. Radiosensitivity of Bombyx mori embryos and its modification by thermal shock

    International Nuclear Information System (INIS)

    Agaev, F.A.; Zakrzhevskaya, D.T.; Yusifov, N.I.; Gaziev, A.I.; AN Azerbajdzhanskoj SSR, Baku

    1991-01-01

    Radiosensitivity of Bombyx mori embryos on days 3-4 of their development is more than 10 times higher than that of 7-9 day embryos. The rate of DNA synthesis in the embryos correlates with their radiosensitivity. Heat treatment (40 deg C, 60 min) of embryos just before γ-irradiation increases their radioresistance (DMF=+1.6), whereas such a treatment immediately after irradiation reduces the survival rate of embryos as compared to the controls irradiated without heat treatment (DMA=-1.5). The radiomodifying effect of the thermal shock on the Bombyx mori embryos is the same with exposure at both the radioresistant and the radiosensitive stage of their development. However, it is more pronounced at the radiosensitive stage

  12. Pressurized thermal shock evaluation of the Calvert Cliffs Unit 1 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Abbott, L.

    1985-09-01

    An evaluation of the risk to the Calvert Cliffs Unit 1 nuclear power plant due to pressurized thermal shock (PTS) has been completed by Oak Ridge National Laboratory (ORNL) with the assistance of several other organizations. This evaluation was part of a Nuclear Regulatory Commission program designed to study the PTS risk to three nuclear plants, the other two plants being Oconee Unit 1 and H.B. Robinson Unit 2. The specific objectives of the program were to (1) provide a best estimate of the frequency of a through-the-wall crack in the pressure vessel at each of the three plants, together with the uncertainty in the estimated frequency and its sensitivity to the variables used in the evaluation; (2) determine the dominant overcooling sequences contributing to the estimated frequency and the associated failures in the plant systems or in operator actions; and (3) evaluate the effectiveness of potential corrective measures

  13. Kinetic and energetic approaches to analysis of scabbing fracture of structural steels under thermal shock

    International Nuclear Information System (INIS)

    Molitvin, A.M.

    2002-01-01

    The regularities of the scabbing fracture of nine brands of structural steels under the conditions of the impact of the nuclear explosion X-ray irradiation are studied. The time dependences of the scabbing strength of the structural materials under thermal shock, initiated by the X-ray irradiation, are established within the frames of the approach to the problem on the scabbing fracture. The time dependences of the critical specific energy of the steels fracture under the conditions of the X-ray irradiation effect are determined within the frames of the energetic approach to the problem on the scabbing fracture, based on the comparison of the sample energy reserve and fracture work [ru

  14. Thermal elastic shock and its effect on TOPEX spacecraft attitude control

    Science.gov (United States)

    Zimbelman, Darrell F.

    1991-01-01

    Thermal elastic shock (TES) is a twice per orbit impulsive disturbance torque experienced by low-Earth orbiting spacecraft. The fundamental equations used to model the TES disturbance torque for typical spacecraft appendages (e.g., solar arrays and antenna booms) are derived in detail. In particular, the attitude-pointing performance of the TOPEX spacecraft, when subjected to the TES disturbance, is analyzed using a three-axis nonlinear time-domain simulation. Results indicate that the TOPEX spacecraft could exceed its roll-axis attitude-control requirement during penumbral transitions, and remain in violation for approximately 150 sec each orbit until the umbra collapses. A localized active-control system is proposed as a solution to minimize and/or eliminate the degrading effects of the TES disturbance.

  15. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

    2014-12-25

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

  16. Reactor pressure vessel failure probability following through-wall cracks due to pressurized thermal shock events

    International Nuclear Information System (INIS)

    Simonen, F.A.; Garnich, M.R.; Simonen, E.P.; Bian, S.H.; Nomura, K.K.; Anderson, W.E.; Pedersen, L.T.

    1986-04-01

    A fracture mechanics model was developed at the Pacific Northwest Laboratory (PNL) to predict the behavior of a reactor pressure vessel following a through-wall crack that occurs during a pressurized thermal shock (PTS) event. This study, which contributed to a US Nuclear Regulatory Commission (NRC) program to study PTS risk, was coordinated with the Integrated Pressurized Thermal Shock (IPTS) Program at Oak Ridge National Laboratory (ORNL). The PNL fracture mechanics model uses the critical transients and probabilities of through-wall cracks from the IPTS Program. The PNL model predicts the arrest, reinitiation, and direction of crack growth for a postulated through-wall crack and thereby predicts the mode of vessel failure. A Monte-Carlo type of computer code was written to predict the probabilities of the alternative failure modes. This code treats the fracture mechanics properties of the various welds and plates of a vessel as random variables. Plant-specific calculations were performed for the Oconee-1, Calvert Cliffs-1, and H.B. Robinson-2 reactor pressure vessels for the conditions of postulated transients. The model predicted that 50% or more of the through-wall axial cracks will turn to follow a circumferential weld. The predicted failure mode is a complete circumferential fracture of the vessel, which results in a potential vertically directed missile consisting of the upper head assembly. Missile arrest calculations for the three nuclear plants predict that such vertical missiles, as well as all potential horizontally directed fragmentation type missiles, will be confined to the vessel enclosre cavity. The PNL failure mode model is recommended for use in future evaluations of other plants, to determine the failure modes that are most probable for postulated PTS events

  17. Facility for endurance tests of thermal insulations

    International Nuclear Information System (INIS)

    Mauersberger, R.

    1984-01-01

    In the following report the design and construction of an experimental facility for endurance tests of thermal insulations is presented. It's name in abbreviation is 'ADI' standing for the German words A nlage zum Dauertest von Isolierungen . This test facility was build by HRB in order to investigate the performance of thermal insulation systems of hot gas ducts for the process heat-reactor-project. The tests are intended to simulate the conditions of reactor operation. They include short-time experiments for selection of insulation-concepts and in a second step long-time experiments as performance tests. During these tests are measured the effective heat conductivity the local heat losses the temperature profiles of the insulation, of the fixing elements and along the wall of the duct. The design-data required to perform all these tasks are shown in the first picture: The gas-atmosphere must be Helium in tests like in reactor with regard to the special thermal and hydraulic properties of Helium and to the influence of Helium on mechanic friction and wear. The hot gas temperature in the PNP-reactor will be 950 deg. C and should be equal in the experiments. The temperature on the cold side of the insulation has to be adjustable from 50 deg. C up to 300 deg. C. The Helium pressure in the hot gas ducts of a HTR-plant is about 42 bar. The ADI was laid out for 70 bar to cover the hole range of interest. A Helium mass flow has to stream through the insulated test duct in order to realize equal temperatures on the hot side of the insulation. A flow rate of 4,5 kg/s is sufficient for this requirement. The axial pressure gradient along the insulation must be the same as in the reactor, because this has an essential influence on the heat losses. This pressure gradient is about 40 Pa/m

  18. Thermal endurance tests on silicone rubber specimens

    International Nuclear Information System (INIS)

    Warburton, C.

    1977-07-01

    Thermal endurance tests have been performed on a range of silicone rubber specimens at temperature above 300 0 C. It is suggested that the rubber mix A2426, the compound from which Wylfa sealing rings are manufactured, will fail at temperatures above 300 0 C within weeks. Hardness measurements show that this particular rubber performs in a similar manner to Walker's S.I.L./60. (author)

  19. Buoyancy effects in overcooling transients calculated for the NRC pressurized thermal shock study

    International Nuclear Information System (INIS)

    Theofanous, T.G.; Iyer, K.; Nourbakhsh, H.P.; Gherson, P.

    1986-05-01

    The thermal-hydraulic responses of three PWRs (Oconee, Calvert Cliffs, and H.B. Robinson), to postulated Pressurized Thermal Shock (PTS) scenarios, which were originally determined by RELAP5 and TRAC calculations, are being further developed here with regard to buoyancy/stratification effects. These three PWRs were the subject of the NRC PTS study, and the present results helped define the thermal-hydraulic conditions utilized in the fracture mechanics calculations carried out at ORNL. The computer program REMIX, which is based on the Regional Mixing Model (RMM), was the analytical tool employed, while Purdue's 1/2-Scale HPI Thermal Mixing facility provided the basis for experimental support. Important mixing and wall heat transfer regimes are delineated on the basis of these results. We conclude that stratification is important only in cases of complete loop stagnation and that mixed-convection effects are important for downcomer flow velocities below approx.0.25 m/s. The stratification is small in magnitude, however it is important in creating a recirculating flow pattern which activates the lower plenum, pump and loop seal volumes, to participate in the mixing process. This mixing process together with the heat input from the wall metal significantly impact the cooldown rates. Heat transfer in the plume region is dominated by forced convection. On the other hand, the presence of the Reactor Pressure Vessel (RPV) wall cladding and wall conduction significantly dampen the free convection effects in the low velocity, mixed-convection, regime. For the stagnant loop cases, all locations outside the plume region are included in this regime. In the presence of natural loop circulation and a uniformly distributed downcomer flow, the mixed convection regime is also expected, however, the forced convection regime can also be observed in highly asymmetric flow behavior

  20. Thermal property testing technique on micro specimen

    International Nuclear Information System (INIS)

    Baba, Tetsuya; Kishimoto, Isao; Taketoshi, Naoyuki

    2000-01-01

    This study aims at establishment of further development on some testing techniques on the nuclear advanced basic research accumulated by the National Research Laboratory of Metrology for ten years. For this purpose, a technology to test heat diffusion ratio and specific heat capacity of less than 3 mm in diameter and 1 mm in thickness of micro specimen and technology to test heat diffusion ratio at micro area of less than 1 mm in area along cross section of less than 10 mm in diameter of column specimen were developed to contribute to common basic technology supporting the nuclear power field. As a result, as an element technology to test heat diffusion ratio and specific heat capacity of the micro specimen, a specimen holding technique stably to hold a micro specimen with 3 mm in diameter could be developed. And, for testing the specific heat capacity by using the laser flush differential calorimetry, a technique to hold two specimen of 5 mm in diameter at their proximities was also developed. In addition, by promoting development of thermal property data base capable of storing thermal property data obtained in this study and with excellent workability in this 1998 fiscal year a data in/out-put program with graphical user interface could be prepared. (G.K.)

  1. COLLISIONLESS ELECTRON–ION SHOCKS IN RELATIVISTIC UNMAGNETIZED JET–AMBIENT INTERACTIONS: NON-THERMAL ELECTRON INJECTION BY DOUBLE LAYER

    International Nuclear Information System (INIS)

    Ardaneh, Kazem; Cai, Dongsheng; Nishikawa, Ken-Ichi

    2016-01-01

    The course of non-thermal electron ejection in relativistic unmagnetized electron–ion shocks is investigated by performing self-consistent particle-in-cell simulations. The shocks are excited through the injection of a relativistic jet into ambient plasma, leading to two distinct shocks (referred to as the trailing shock and leading shock) and a contact discontinuity. The Weibel-like instabilities heat the electrons up to approximately half of the ion kinetic energy. The double layers formed in the trailing and leading edges then accelerate the electrons up to the ion kinetic energy. The electron distribution function in the leading edge shows a clear, non-thermal power-law tail which contains ∼1% of electrons and ∼8% of the electron energy. Its power-law index is −2.6. The acceleration efficiency is ∼23% by number and ∼50% by energy, and the power-law index is −1.8 for the electron distribution function in the trailing edge. The effect of the dimensionality is examined by comparing the results of three-dimensional simulations with those of two-dimensional simulations. The comparison demonstrates that electron acceleration is more efficient in two dimensions.

  2. Insights into chondrule formation process and shock-thermal history of the Dergaon chondrite (H4-5

    Directory of Open Access Journals (Sweden)

    D. Ray

    2017-05-01

    Full Text Available The Dergaon fall represents a shock-melted H4-5 (S5 ordinary chondrite which includes at least ten textural varieties of chondrules and belongs to the high chondrule-matrix ratio type. Our study reveals that the chondrules are of diverse mineralogy with variable olivine-pyroxene ratios (Type II, igneous melt textures developed under variable cooling rates and formed through melt fractionations from two different melt reservoirs. Based on the experimental analogues, mineralogical associations and phase compositions, it is suggested that the Dergaon chondrules reflect two contrasting environments: a hot, dust-enriched and highly oxidized nebular environment through melting, without significant evaporation, and an arrested reducing environment concomitant with major evaporation loss of alkali and highly volatile trace elements. Coexistence of chlorapatite and merrillite suggests formation of the Dergaon matrix in an acidic accretionary environment. Textural integration and chemical homogenization occurred at ∼1 atmospheric pressure and a mean temperature of 765 °C mark the radiogenic thermal event. Equilibrated shock features (olivine mosaicism, diaplectic plagioclase, polycrystalline troilite due to an impact-induced thermal event reflect a shock pressure >45 GPa and temperature of 600 °C. By contrast, the local disequilibrium shock features (silicate melt veins comprising of olivine crystallites, troilite melt veins and metal droplets correspond to a shock pressure up to 75 GPa and temperature >950 °C.

  3. Prediction of cleavage crack propagation and arrest in a nuclear pressure vessel steel (16MND5) under thermal shock

    International Nuclear Information System (INIS)

    Yang, Xiaoyu

    2015-01-01

    the critical stress was developed. The results of this analytical model is in good agreement with the empirical criterion identified. In order to test the validity of the identified criterion, the prediction of the crack propagation and arrest by the criterion was first performed for isothermal tests. It was performed both on CT25 specimens (crack was solicited in mode I) and on ring specimens in mixed mode loading which were carried out at three different temperatures. The numerical results of prediction were in good agreement with experiments. They showed the validity of the criterion for experiments under isothermal loading for two different specimen geometries. In order to test the validity of criterion for the situation of thermal shock, experiments were carried out on ring specimens. At first, one ring specimen was cooled down to -150 C, and then hot water (∼90 C) was injected through the inner side of the ring specimen. At the same time of thermal shock, this specimen was submitted to a mechanical compressive loading (-750 kN). The prediction of crack propagation and arrest by the criterion for this situation was calculated in both 2D and 3D. The predicted results were in good agreement with experiments for both crack speed and crack length. This confirmed that the criterion is relevant to predict the crack propagation and arrest for thermal shock. In parallel, some experiments were performed on extended CT25 specimens (same height but double the width of the CT25 specimen). The crack path on this kind of specimen was curved. A statistical effect by a random selection in the propagation direction was introduced to take into account the instability during the crack propagation. The numerical results correctly reproduce the curvature and the dispersion of the crack paths. (author) [fr

  4. Thermal Module Tests with Irradiated 070 Detectors.

    CERN Document Server

    HOWCROFT, C L F

    1998-01-01

    Four n-in-n detectors were irradiated at KEK to a fluence of 3*1014 protons cm-2. These were used to construct a thermal barrel module to 070 drawings with an A3-90 baseboard at the Rutherford Appleton Laboratory. Thermal testes were conducted on the module, examining the runaway point and the temperatures across the silicon. The results obtained were used to calculate the runaway point under ATLAS conditions. It was concluded that this module meets the specifications in the Technical Design Report, of 160 mW mm-2@ 0°C for runaway and less than 5°C across the silicon. The module was also compared to a Finite Element Analysis, and showed a good agreement.

  5. Thermal modelling of Advanced LIGO test masses

    International Nuclear Information System (INIS)

    Wang, H; Dovale Álvarez, M; Mow-Lowry, C M; Freise, A; Blair, C; Brooks, A; Kasprzack, M F; Ramette, J; Meyers, P M; Kaufer, S; O’Reilly, B

    2017-01-01

    High-reflectivity fused silica mirrors are at the epicentre of today’s advanced gravitational wave detectors. In these detectors, the mirrors interact with high power laser beams. As a result of finite absorption in the high reflectivity coatings the mirrors suffer from a variety of thermal effects that impact on the detectors’ performance. We propose a model of the Advanced LIGO mirrors that introduces an empirical term to account for the radiative heat transfer between the mirror and its surroundings. The mechanical mode frequency is used as a probe for the overall temperature of the mirror. The thermal transient after power build-up in the optical cavities is used to refine and test the model. The model provides a coating absorption estimate of 1.5–2.0 ppm and estimates that 0.3 to 1.3 ppm of the circulating light is scattered onto the ring heater. (paper)

  6. Dosification of a cement-talc-chamotte refractory mortar subjected to thermal shock

    Directory of Open Access Journals (Sweden)

    Kittl, P.

    1992-03-01

    Full Text Available A cement-talc-chamotte refractory mixture was dosified by subjecting the same to thermal shock. To this end, specimens compacted to 350 Kg/cm2 through compression as well as specimens compacted manually were prepared. All the specimens were submitted to an initial working temperature of 1000ºC and then left to cool down to room temperature. The thermal shock was originated by heating the specimens in an oven till reaching a certain temperature T¡ and then quenching the same through immersion in water at 20ºC; temperature T¡ was varied between 170ºC and 970ºC by means of 100ºC increments. The optimum dosification amounting to 90 % cement-talc and 10 % chamotte was obtained by studying mean stress at compression fracture of five cement-talc-chamote mixtures as a function of thermal shock. In addition, thermal fatigue exhibited by the optimum dosification was studied through the determination of mean loss in compressive strength, which amounted to 52% after 7 cycles with ΔT = 500ºC.

    Se dosificó una mezcla refractaria cemento-talco-chamota sometiéndola a un choque térmico. Con este objeto se fabricaron probetas compactadas a 350 kg/cm2 mediante compresión y probetas compactadas manualmente. Se aplicó a todas ellas una temperatura inicial de trabajo a 1.000 ºC, luego se las dejó enfriar hasta que alcanzaran la temperatura de sala del laboratorio. El choque térmico se originó calentando las probetas en un horno hasta una temperatura T¡ y luego se las enfrió súbitamente sumergiéndolas en agua a 20 ºC; la temperatura T¡ varió entre 170 ºC y 970 ºC con incrementos de 100 ºC. La dosificación óptima, 90% cemento-talco y 10% chamota, se obtuvo estudiando la tensión media de fractura a la compresión de cinco mezclas de cemento-talco-chamota en función del choque térmico. Se estudió además la fatiga térmica de la dosificación óptima determinando la

  7. Hexavalent chromium, a lung carcinogen, confers resistance to thermal stress and interferes with heat shock protein expression in human bronchial epithelial cells.

    Science.gov (United States)

    Abreu, Patrícia L; Cunha-Oliveira, Teresa; Ferreira, Leonardo M R; Urbano, Ana M

    2018-03-16

    Exposure to hexavalent chromium [Cr(VI)], a lung carcinogen, triggers several types of cellular stresses, namely oxidative, genotoxic and proteotoxic stresses. Given the evolutionary character of carcinogenesis, it is tempting to speculate that cells that survive the stresses produced by this carcinogen become more resistant to subsequent stresses, namely those encountered during neoplastic transformation. To test this hypothesis, we determined whether pre-incubation with Cr(VI) increased the resistance of human bronchial epithelial cells (BEAS-2B cells) to the antiproliferative action of acute thermal shock, used here as a model for stress. In line with the proposed hypothesis, it was observed that, at mildly cytotoxic concentrations, Cr(VI) attenuated the antiproliferative effects of both cold and heat shock. Mechanistically, Cr(VI) interfered with the expression of two components of the stress response pathway: heat shock proteins Hsp72 and Hsp90α. Specifically, Cr(VI) significantly depleted the mRNA levels of the former and the protein levels of the latter. Significantly, these two proteins are members of heat shock protein (Hsp) families (Hsp70 and Hsp90, respectively) that have been implicated in carcinogenesis. Thus, our results confirm and extend previous studies showing the capacity of Cr(VI) to interfere with the expression of stress response components.

  8. Cracking of a layered medium on an elastic foundation under thermal shock

    Science.gov (United States)

    Rizk, Abd El-Fattah A.; Erdogan, Fazil

    1988-01-01

    The cladded pressure vessel under thermal shock conditions which is simulated by using two simpler models was studied. The first model (Model 1) assumes that, if the crack size is very small compared to the vessel thickness, the problem can be treated as a semi-infinite elastic medium bonded to a very thin layer of different material. However, if the crack size is of the same order as the vessel thickness, the curvature effects may not be negligible. In this case it is assumed that the relatively thin walled hollow cylinder with cladding can be treated as a composite beam on an elastic foundation (Model 2). In both models, the effect of surface cooling rate is studied by assuming the temperature boundary condition to be a ramp function. The calculated results include the transient temperature, thermal stresses in the uncracked medium and stress intensity factors which are presented as a function of time, and the duration of cooling ramp. The stress intensity factors are also presented as a function of the size and the location of the crack. The problem is solved for two bonded materials of different thermal and mechanical properties. The mathematical formulation results in two singular integral equations which are solved numerically. The results are given for two material pairs, namely an austenitic steel layer welded on a ferritic steel substrate, and a ceramic coating on ferritic steel. In the case of the yielded clad, the stress intensity factors for a crack under the clad are determined by using a plastic strip model and are compared with elastic clad results.

  9. Thermal Testing Methods for Solar Dryers

    DEFF Research Database (Denmark)

    Singh, Shobhana

    2017-01-01

    Solar food drying is a complex heat and mass transfer phenomena which depend on a number of drying process-dependent parameters such as operating conditions and characteristics of the food product to be dried. The variation in these parameters significantly affects the overall performance...... of the dryer system. Since commercial growth and acceptance of any solar dryer system momentously depend on its performance guarantee, the development of a standard methodology for their thermal testing has become necessary. The standard testing method not only provides better performance management...... of the dryer system but allows the manufacturers to achieve competitive efficiency and good product quality by comparing the available designs. In this chapter, an extensive review of solar dryer performance evaluation has been carried out. Furthermore, the chapter describes the existing testing procedures...

  10. Thermal Protection Test Bed Pathfinder Development Project

    Science.gov (United States)

    Snapp, Cooper

    2015-01-01

    In order to increase thermal protection capabilities for future reentry vehicles, a method to obtain relevant test data is required. Although arc jet testing can be used to obtain some data on materials, the best method to obtain these data is to actually expose them to an atmospheric reentry. The overprediction of the Orion EFT-1 flight data is an example of how the ground test to flight traceability is not fully understood. The RED-Data small reentry capsule developed by Terminal Velocity Aerospace is critical to understanding this traceability. In order to begin to utilize this technology, ES3 needs to be ready to build and integrate heat shields onto the RED-Data vehicle. Using a heritage Shuttle tile material for the heat shield will both allow valuable insight into the environment that the RED-Data vehicle can provide and give ES3 the knowledge and capability to build and integrate future heat shields for this vehicle.

  11. Shock and vibration tests of uranium mononitride fuel pellets for a space power nuclear reactor

    Science.gov (United States)

    Adams, D. W.

    1972-01-01

    Shock and vibration tests were conducted on cylindrically shaped, depleted, uranium mononitride (UN) fuel pellets. The structural capabilities of the pellets were determined under exposure to shock and vibration loading which a nuclear reactor may encounter during launching into space. Various combinations of diametral and axial clearances between the pellets and their enclosing structures were tested. The results of these tests indicate that for present fabrication of UN pellets, a diametral clearance of 0.254 millimeter and an axial clearance of 0.025 millimeter are tolerable when subjected to launch-induced loads.

  12. Elastic moduli, damping and modulus of rupture changes in a high alumina refractory castable due to different types of thermal shock

    Directory of Open Access Journals (Sweden)

    Pereira, A. H. A.

    2012-06-01

    Full Text Available The work herein verifies the changes of the elastic moduli, damping and modulus of rupture (MOR of a high alumina refractory castable due to heating, cooling and heating-cooling thermal shock damage. Twelve prismatic specimens were prepared for the tests and divided into four groups. The thermal shocks were performed on three groups, each containing three specimens having abrupt temperature changes of 1100°C during heating in the first group, during cooling in the second and during heating followed by cooling in the third group. The fourth group, which was taken as a reference did not receive any thermal shock. The elastic moduli were measured after each thermal shock cycle. After 10 cycles, the MOR, the damping and the damping dependence on excitation amplitude were measured at room temperature for all specimens. The elastic moduli showed a similar decrease and the damping a similar increase due to the cooling and heating-cooling thermal shocks. The heating thermal shocks caused no significant changes on the elastic moduli and damping. However, the MOR appeared to be sensitive to the heating thermal shock. This work also shows that the damping for the studied refractory castable is non-linear (i.e., amplitude of excitation sensitive and that this non-linearity increases when the damage level rises.

    En este trabajo se investigaron las alteraciones de los módulos elásticos dinámicos, del amortiguamiento y del módulo de rotura (MOR de un material refractario moldeable de alta alúmina después de recibir choques térmicos de calentamiento, enfriamiento y calentamiento seguido de enfriamiento (calentamiento-enfriamiento. Para ello se prepararon doce cuerpos prismáticos dividiéndolos en cuatro grupos. Los choques térmicos se le aplicaron a sólo tres grupos, cada uno con tres muestras. Al primer grupo se le aplicó un cambio brusco de temperatura de 1100 °C en calentamiento, en enfriamiento al segundo grupo y calentamiento seguido

  13. Design and testing of a shock absorber for a type 1 container

    International Nuclear Information System (INIS)

    Sappok, M.; Beine, B.; Rittscher, D.

    1993-01-01

    A shock-absorber will be required for a rad. waste 'Konrad' type 1 container made of ductile cast iron whenever it will be used as a type B container according to the IAEA-Regulations for the Safe Transport of Radioactive materials. The shock-absorber has to protect the type B container during shipping such as to withstand the accident scenarios that are covered by the IAEA-Regulation tests without substantial loss of its shielding and tightness functions. The designation as type 1 container originates from German regulations for the intermediate storage site Gorleben and the final depository Konrad-mine. These regulations call for the limits on outside dimensions of 1700 mm in length, 1600 mm in width and 1450 mm in height as well as for a limit of 20 Mg on total weight without shock-absorber. The relatively simple design method for the shock-absorber has been validated by the test results. It can be extended to other materials and designs for shock-absorbers if reliable force-displacement-diagrams are available for the structural elements from which the absorbed energy and the displacements can be calculated by integration. In order to account for the dynamic effects, the better approximation of the true duration of the impact would be helpful. The present limit of 0.5 R p0,2 on the nominal stresses should be discussed because the large number of tests on containers made of ductile cast iron that have been performed up to now have shown a substantial level of conservatism on this respect. The sharply tapered pipes on edge Kl of the shock-absorbers should be replaced by pipe bends. This will result in smaller accelerations and in an even higher level of protection of the container than effected by the tested shock-absorber

  14. 40 CFR 90.329 - Catalyst thermal stress test.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress test. 90.329... Equipment Provisions § 90.329 Catalyst thermal stress test. (a) Oven characteristics. The oven used for thermally stressing the test catalyst must be capable of maintaining a temperature of 500 ±5 °C and 1000 ±10...

  15. Intra-operative defibrillation testing and clinical shock efficacy in patients with implantable cardioverter-defibrillators

    DEFF Research Database (Denmark)

    Bänsch, Dietmar; Bonnemeier, Hendrik; Brandt, Johan

    2015-01-01

    AIMS: This trial was designed to test the hypothesis that shock efficacy during follow-up is not impaired in patients implanted without defibrillation (DF) testing during first implantable cardioverter-defibrillator (ICD) implantation. METHODS AND RESULTS: Between February 2011 and July 2013, 107...

  16. Experimental investigation of a PCM-HP heat sink on its thermal performance and anti-thermal-shock capacity for high-power LEDs

    International Nuclear Information System (INIS)

    Wu, Yuxuan; Tang, Yong; Li, Zongtao; Ding, Xinrui; Yuan, Wei; Zhao, Xuezhi; Yu, Binhai

    2016-01-01

    Highlights: • A phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) is designed. • The PCM-HP heat sink can significantly lower the LED heating rate and temperature. • The PCM-HP heat sink achieves a best anti-thermal-shock capacity in LED cyclic working modes. - Abstract: High-power LEDs demonstrate a number of benefits compared with conventional incandescent lamps and fluorescent lamps, including a longer lifetime, higher brightness and lower power consumption. However, owing to their severe high heat flux, it is difficult to develop effective thermal management of high-power LEDs, especially under cyclic working modes, which cause serious periodic thermal stress and limit further development. Focusing on the above problem, this paper designed a phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) that consists of a PCM base, adapter plate, heat pipe and finned radiator. Different parameters, such as three types of interior materials to fill the heat sink, three LED power inputs and eight LED cyclic working modes, were separately studied to investigate the thermal performance and anti-thermal-shock capacity of the PCM-HP heat sink. The results show that the PCM-HP heat sink possesses remarkable thermal performance owing to the reduction of the LED heating rate and peak temperature. More importantly, an excellent anti-thermal-shock capacity of the PCM-HP heat sink is also demonstrated when applied in LED cyclic working modes, and this capacity demonstrates the best range.

  17. Fracture risk assessment for the pressurized water reactor pressure vessel under pressurized thermal shock events

    International Nuclear Information System (INIS)

    Chou, Hsoung-Wei; Huang, Chin-Cheng

    2016-01-01

    Highlight: • The PTS loading conditions consistent with the USNRC's new PTS rule are applied as the loading condition for a Taiwan domestic PWR. • The state-of-the-art PFM technique is employed to analyze a reactor pressure vessel. • Novel flaw model and embrittlement correlation are considered in the study. • The RT-based regression formula of NUREG-1874 was also utilized to evaluate the failure risks of RPV. • For slightly embrittled RPV, the SO-1 type PTSs play more important role than other types of PTS. - Abstract: The fracture risk of the pressurized water reactor pressure vessel of a Taiwan domestic nuclear power plant has been evaluated according to the technical basis of the U.S.NRC's new pressurized thermal shock (PTS) screening criteria. The ORNL's FAVOR code and the PNNL's flaw models were employed to perform the probabilistic fracture mechanics analysis associated with plant specific parameters of the domestic reactor pressure vessel. Meanwhile, the PTS thermal hydraulic and probabilistic risk assessment data analyzed from a similar nuclear power plant in the United States for establishing the new PTS rule were applied as the loading conditions. Besides, an RT-based regression formula derived by the U.S.NRC was also utilized to verify the through-wall cracking frequencies. It is found that the through-wall cracking of the analyzed reactor pressure vessel only occurs during the PTS events resulted from the stuck-open primary safety relief valves that later reclose, but with only an insignificant failure risk. The results indicate that the Taiwan domestic PWR pressure vessel has sufficient structural margin for the PTS attack until either the current license expiration dates or during the proposed extended operation periods.

  18. Reynolds stress turbulence model applied to two-phase pressurized thermal shocks in nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mérigoux, Nicolas, E-mail: nicolas.merigoux@edf.fr; Laviéville, Jérôme; Mimouni, Stéphane; Guingo, Mathieu; Baudry, Cyril

    2016-04-01

    Highlights: • NEPTUNE-CFD is used to model two-phase PTS. • k-ε model did produce some satisfactory results but also highlights some weaknesses. • A more advanced turbulence model has been developed, validated and applied for PTS. • Coupled with LIM, the first results confirmed the increased accuracy of the approach. - Abstract: Nuclear power plants are subjected to a variety of ageing mechanisms and, at the same time, exposed to potential pressurized thermal shock (PTS) – characterized by a rapid cooling of the internal Reactor Pressure Vessel (RPV) surface. In this context, NEPTUNE-CFD is used to model two-phase PTS and give an assessment on the structural integrity of the RPV. The first available choice was to use standard first order turbulence model (k-ε) to model high-Reynolds number flows encountered in Pressurized Water Reactor (PWR) primary circuits. In a first attempt, the use of k-ε model did produce some satisfactory results in terms of condensation rate and temperature field distribution on integral experiments, but also highlights some weaknesses in the way to model highly anisotropic turbulence. One way to improve the turbulence prediction – and consequently the temperature field distribution – is to opt for more advanced Reynolds Stress turbulence Model. After various verification and validation steps on separated effects cases – co-current air/steam-water stratified flows in rectangular channels, water jet impingements on water pool free surfaces – this Reynolds Stress turbulence Model (R{sub ij}-ε SSG) has been applied for the first time to thermal free surface flows under industrial conditions on COSI and TOPFLOW-PTS experiments. Coupled with the Large Interface Model, the first results confirmed the adequacy and increased accuracy of the approach in an industrial context.

  19. Linking physiological and cellular responses to thermal stress: β-adrenergic blockade reduces the heat shock response in fish.

    Science.gov (United States)

    Templeman, Nicole M; LeBlanc, Sacha; Perry, Steve F; Currie, Suzanne

    2014-08-01

    When faced with stress, animals use physiological and cellular strategies to preserve homeostasis. We were interested in how these high-level stress responses are integrated at the level of the whole animal. Here, we investigated the capacity of the physiological stress response, and specifically the β-adrenergic response, to affect the induction of the cellular heat shock proteins, HSPs, following a thermal stress in vivo. We predicted that blocking β-adrenergic stimulation during an acute heat stress in the whole animal would result in reduced levels of HSPs in red blood cells (RBCs) of rainbow trout compared to animals where adrenergic signaling remained intact. We first determined that a 1 h heat shock at 25 °C in trout acclimated to 13 °C resulted in RBC adrenergic stimulation as determined by a significant increase in cell swelling, a hallmark of the β-adrenergic response. A whole animal injection with the β2-adrenergic antagonist, ICI-118,551, successfully reduced this heat-induced RBC swelling. The acute heat shock caused a significant induction of HSP70 in RBCs of 13 °C-acclimated trout as well as a significant increase in plasma catecholamines. When heat-shocked fish were treated with ICI-118,551, we observed a significant attenuation of the HSP70 response. We conclude that circulating catecholamines influence the cellular heat shock response in rainbow trout RBCs, demonstrating physiological/hormonal control of the cellular stress response.

  20. Application of the French codes to the pressurized thermal shocks assessment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya; Wang, Rong Shan; Yu, Weiwei; Lu, Feng; Zhang, Guo Dong; Xue, Fei; Chen, Zhilin [Suzhou Nuclear Power Research Institute, Life Management Center, Suzhou (China); Qian, Guian [Paul Scherrer Institute, Nuclear Energy and Safety Department, Villigen (Switzerland); Shi, Jinhua [Amec Foster Wheeler, Clean Energy Department, Gloucester (United Kingdom)

    2016-12-15

    The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. This paper introduces an integrity assessment of an RPV subjected to a PTS transient based on the French codes. In the USA, the 'screening criterion' for maximum allowable embrittlement of RPV material is developed based on the probabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, which are developed based on the deterministic fracture mechanics, there is no 'screening criterion'. In this paper, the methodology in the RCC-M and RSE-M codes, which are used for PTS analysis, are firstly discussed. The bases of the French codes are compared with ASME and FAVOR codes. A case study is also presented. The results show that the method in the RCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF) may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significant differences in the assessment results. Therefore, homogenization of the codes in the long time operation of nuclear power plants is needed.

  1. Pressurized thermal shock. Thermo-hydraulic conditions in the CNA-I reactor pressure vessel

    International Nuclear Information System (INIS)

    Ventura, Mirta A.; Rosso, Ricardo D.

    2002-01-01

    In this paper we analyze several reports issued by the Utility (Nucleo Electrica S.A.) and related to Reactor Pressure Vessel (RPV) phenomena in the CNA-I Nuclear Power Plant. These analyses are aimed at obtaining conclusions and establishing criteria ensuring the RPV integrity. Special attention was given to the effects ECCS cold-water injection at the RPV down-comer leading to pressurized thermal shock scenarios. The results deal with hypothetical primary system pipe breaks of different sizes, the inadvertent opening of the pressurizer safety valve, the double guillotine break of a live steam line in the containment and the inadvertent actuation pressurizer heaters. Modeling conditions were setup to represent experiments performed at the UPTF, under the hypothesis that they are representative of those that, hypothetically, may occur at the CNA-I. No system scaling analysis was performed, so this assertion and the inferred conclusions are no fully justified, at least in principle. The above mentioned studies, indicate that the RPV internal wall surface temperature will be nearly 40 degree. It was concluded that they allowed a better approximation of PTS phenomena in the RPV of the CNA-I. Special emphasis was made on the influence of the ECCS systems on the attained RPV wall temperature, particularly the low-pressure TJ water injection system. Some conservative hypothesis made, are discussed in this report. (author)

  2. Structural integrity assessment of the reactor pressure vessel under the pressurized thermal shock loading

    International Nuclear Information System (INIS)

    Chen, Mingya; Lu, Feng; Wang, Rongshan; Ren, Ai

    2014-01-01

    Highlights: • The regulation and the code are proved to be conservative in the integrity assessment. • This study is helpful to understand the complex influence of the parameters. • The most dangerous case is given for the reference transient. - Abstract: Fracture mechanics analysis of pressurized thermal shock (PTS) is the key element of the integrity evaluation of the nuclear reactor pressure vessel (RPV). While the regulation of 10 CFR 50.61 and the ASME Code provide the guidance for the structural integrity, the guidance has been prepared under conservative assumptions. In this paper, the effects of conservative assumptions involved in the PTS analysis were investigated. The influence of different parameters, such as crack size, cladding effect and neutron fluence, were reviewed based on 3-D finite element analyses. Also, the sensitivity study of elastic–plastic approach, crack type and cladding thickness were reviewed. It was shown that crack depth, crack type, plastic effect and cladding thickness change the safety margin (SM) significantly, and the SM at the deepest point of the crack is not always smaller than that of the surface point, indicating that both the deepest and surface points of the crack front should be considered. For the reference transient, deeper cracks always give more conservative prediction. So compared to the prescribed analyses of a set of postulated defects with varying depths in the ASME code, it only needs to assess the crack with maximum depth in the code for the reference transient according to the conclusions

  3. A quantitative methodology for reactor vessel pressurized thermal shock decision making

    International Nuclear Information System (INIS)

    Ackerson, D.S.; Balkey, K.R.; Meyer, T.A.; Ofstun, R.P.; Rupprecht, S.D.; Sharp, D.R.

    1983-01-01

    The recent operating experience of the Pressurized Water Reactor (PWR) Industry has focused increasing attention on the issue of reactor vessel pressurized thermal shock (PTS). Previous reactor vessel integrity concerns have led to changes in vessel and plant system design and to operating procedures, and increased attention to the PTS issue is causing consideration of further modifications. Events such as excess feedwater, loss of normal feedwater, and steam generator tube rupture have led to significant primary system cooldowns. Each of these cooldown transients occurred concurrently with a relatively high primary system pressure. Considerations of these and other postulated cooldown events has drawn attention to the impact of operator action and control system effects on reactor vessel PTS. A methodology, which couples event sequence analysis with probabilistic fracture mechanics analyses, was developed to identify those events that are of primary concern for reactor vessel integrity. Operating experience is utilized to aid in defining the appropriate event sequences and event frequencies of occurrence for the evaluation. (orig./RW)

  4. IPTS [Integrated Pressurized-Thermal-Shock] study for H.B. Robinson (HBR-HYPO)

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1990-01-01

    A primary purpose of the US Nuclear Regulatory Commission (NRC) Integrated Pressurized-Thermal-Shock (IPTS) Program, completed in 1985, was to develop an integrated probabilistic approach for evaluating pressurized water reactor (PWR) pressure vessel integrity; and the scope included the application of the methodology to three ''high risk'' PWR plants. The three plants selected were Oconee Unit 1, Calvert Cliffs Unit 1, and HBRobinson Unit 2 (HBR-2); and the plant studies were conducted in that order. As a result of this sequence and the developmental nature of the program, the HBR-2 study was the more complete and state-of-the-art. However, by the time the HBR-2 study was conducted, a reevaluation of vessel chemistry and reference nil-ductility transition temperature (RT NDT ) had indicated relatively low concentrations of copper and nickel and low values of initial RT NDT (RT NDT 0 ), resulting in very low probabilities of failure. Thus, for illustrative purposes, copper, nickel, and RT NDT 0 were increased so that RT NDT (2σ) = 270 degree F for the critical weld at 32 EFPY. This value of RT NDT corresponds, of course, to the NRC PTS-Rule screening criteria (10 CFR 5.61). This hypothetical ''plant'' was referred to as HBR-HYPO, and it was identical to HBR-2 in every respect except for the concentrations of copper and nickel and the value of RT NDT 0 for the welds. 3 refs

  5. Application of the French Codes to the Pressurized Thermal Shocks Assessment

    Directory of Open Access Journals (Sweden)

    Mingya Chen

    2016-12-01

    Full Text Available The integrity of a reactor pressure vessel (RPV related to pressurized thermal shocks (PTSs has been extensively studied. This paper introduces an integrity assessment of an RPV subjected to a PTS transient based on the French codes. In the USA, the “screening criterion” for maximum allowable embrittlement of RPV material is developed based on the probabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, which are developed based on the deterministic fracture mechanics, there is no “screening criterion”. In this paper, the methodology in the RCC-M and RSE-M codes, which are used for PTS analysis, are firstly discussed. The bases of the French codes are compared with ASME and FAVOR codes. A case study is also presented. The results show that the method in the RCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significant differences in the assessment results. Therefore, homogenization of the codes in the long time operation of nuclear power plants is needed.

  6. Application of the French codes to the pressurized thermal shocks assessment

    International Nuclear Information System (INIS)

    Chen, Mingya; Wang, Rong Shan; Yu, Weiwei; Lu, Feng; Zhang, Guo Dong; Xue, Fei; Chen, Zhilin; Qian, Guian; Shi, Jinhua

    2016-01-01

    The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. This paper introduces an integrity assessment of an RPV subjected to a PTS transient based on the French codes. In the USA, the 'screening criterion' for maximum allowable embrittlement of RPV material is developed based on the probabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, which are developed based on the deterministic fracture mechanics, there is no 'screening criterion'. In this paper, the methodology in the RCC-M and RSE-M codes, which are used for PTS analysis, are firstly discussed. The bases of the French codes are compared with ASME and FAVOR codes. A case study is also presented. The results show that the method in the RCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF) may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significant differences in the assessment results. Therefore, homogenization of the codes in the long time operation of nuclear power plants is needed

  7. Influence of Test Section Geometry on the Blast Environment in an Explosively Driven Conical Shock Tube

    Science.gov (United States)

    2018-03-30

    ARL-TR-8335•MAR 2018 US Army Research Laboratory Influence of Test Section Geometry on theBlast Environment in an Explosively DrivenConical Shock...ARL-TR-8335•MAR 2018 US Army Research Laboratory Influence of Test Section Geometry on theBlast Environment in an Explosively DrivenConical Shock...TITLE AND SUBTITLE    5a. CONTRACT NUMBER  5b. GRANT NUMBER  5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S)    5d.  PROJECT  NUMBER  5e. TASK NUMBER  5f

  8. Finite Element Modeling of Material Fatigue and Cracking Problems for Steam Power System HP Devices Exposed to Thermal Shocks

    Directory of Open Access Journals (Sweden)

    Pawlicki Jakub

    2016-09-01

    Full Text Available The paper presents a detailed analysis of the material damaging process due to low-cycle fatigue and subsequent crack growth under thermal shocks and high pressure. Finite Element Method (FEM model of a high pressure (HP by-pass valve body and a steam turbine rotor shaft (used in a coal power plant is presented. The main damaging factor in both cases is fatigue due to cycles of rapid temperature changes. The crack initiation, occurring at a relatively low number of load cycles, depends on alternating or alternating-incremental changes in plastic strains. The crack propagation is determined by the classic fracture mechanics, based on finite element models and the most dangerous case of brittle fracture. This example shows the adaptation of the structure to work in the ultimate conditions of high pressure, thermal shocks and cracking.

  9. Release of Bacterial Spores from the Inner Walls of a Stainless Steel Cup Subjected to Thermal Stresses and Mechanical Shock

    Science.gov (United States)

    Wolochow, H.; Chatigny, M.; Hebert, J.

    1973-01-01

    The release and fallout of particulates from surfaces afforded thermal or impact stress is of concern for control of contamination of Mars from planetary landing vehicles. A metal vessel contaminated by aerosols of spores was used as a model system and the fallout of spores as affected by various mechanisms was examined. Thermal stresses simulating those expected on the Mars lander dislodged approximately .01% of the aerosol deposited surface burden as did a landing shock of 8 to 10G deceleration. Spores imprinted by finger or swab contact yielded similar results. In all cases where repeated cycling of temperature, motion, or shock were employed the majority of fallout occurred in the first cycle. Particles released from the surface were predominantly in the size range 1 to 5 microns.

  10. Thermal Hydraulic Tests for Reactor Core Safety

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S. K.; Baek, W. P.; Chun, S. Y. (and others)

    2007-06-15

    The main objectives of the present project are to resolve the current issues of reactor core thermal hydraulics, to develop an advanced measurement and analytical techniques, and to perform reactor core safety verification tests. 6x6 reflood experiments, various heat transfer experiments using Freon, and experiments on the spacer grids effects on the post-dryout are carried out using spacer grids developed in Korea in order to resolve the current issues of the reactor core thermal hydraulics. In order to develop a reflood heat transfer model, the detailed reflood phenomena are visualized and measured using round tube and 2x2 rod bundle. A detailed turbulent mixing phenomenon for subchannels is measured using advanced measurement techniques such as LDV and PIV. MARS and MATRA codes developed in Korea are assessed, verified and improved using the obtained experimental data. Finally, a systematic quality assurance program and experimental data generation system has been constructed in order to increase the reliability of the experimental data.

  11. Flexible thermal cycle test equipment for concentrator solar cells

    Science.gov (United States)

    Hebert, Peter H [Glendale, CA; Brandt, Randolph J [Palmdale, CA

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  12. Shock absorber

    International Nuclear Information System (INIS)

    Nemeth, J.D.

    1981-01-01

    A shock absorber for the support of piping and components in a nuclear power plant is described. It combines a high degree of stiffness under sudden shocks, e.g. seismic disturbances, with the ability to allow for thermal expansion without resistance when so required. (JIW)

  13. Evolution of seismic shock test qualification of equipment

    International Nuclear Information System (INIS)

    Berriaud, C.

    1979-01-01

    From the first nuclear power plants a new industrial problem is appeared: the seismic test qualification of equipment. Nothing was existing in this range. Methods and test experiments were to be studied and perfected in order to obtain safe results. This paper presents the evolution of this question up to now [fr

  14. 14 CFR 25.723 - Shock absorption tests.

    Science.gov (United States)

    2010-01-01

    ... the greater value of landing impact energy. (2) The test attitude of the landing gear unit and the... manner consistent with the development of rational or conservative limit loads. (b) The landing gear may... acting during the landing impact. (c) In lieu of the tests prescribed in this section, changes in...

  15. Thermal hydraulic evaluation for an experimental facility to investigate pressurized thermal shock (PTS) in CDTN/CNEN; Avaliacao termo-hidraulica da montagem experimental de choque termico pressurizado do CDTN/CNEN

    Energy Technology Data Exchange (ETDEWEB)

    Palmieri, Elcio T.; Navarro, Moyses A.; Aronne, Ivam D.; Terra, Jose L. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)

    2002-07-01

    The goal of the work presented in this paper is to provide necessary thermal hydraulics information to the design of an experimental installation to investigate the Pressurized Thermal Shock (PTS) to be implemented at Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN). The envisaged installation has a test section that represents, in a small scale, a pressure vessel of a nuclear reactor. This test section will be heated and then exposed to a PTS in order to evaluate the appearance and development of cracks. To verify the behavior of the temperatures of the pressure vessel after a sudden flood through the annulus, calculations were made using the RELAP5/MOD 3.2.2 gamma code. Different outer radiuses were studied for the annular region. The results showed that the smaller annulus spacing (20 mm) anticipates the wetting of the surface and produces a higher cooling of the external surface, which stays completely wet for a longer time. (author)

  16. Methane Lunar Surface Thermal Control Test

    Science.gov (United States)

    Plachta, David W.; Sutherlin, Steven G.; Johnson, Wesley L.; Feller, Jeffrey R.; Jurns, John M.

    2012-01-01

    NASA is considering propulsion system concepts for future missions including human return to the lunar surface. Studies have identified cryogenic methane (LCH4) and oxygen (LO2) as a desirable propellant combination for the lunar surface ascent propulsion system, and they point to a surface stay requirement of 180 days. To meet this requirement, a test article was prepared with state-of-the-art insulation and tested in simulated lunar mission environments at NASA GRC. The primary goals were to validate design and models of the key thermal control technologies to store unvented methane for long durations, with a low-density high-performing Multi-layer Insulation (MLI) system to protect the propellant tanks from the environmental heat of low Earth orbit (LEO), Earth to Moon transit, lunar surface, and with the LCH4 initially densified. The data and accompanying analysis shows this storage design would have fallen well short of the unvented 180 day storage requirement, due to the MLI density being much higher than intended, its substructure collapse, and blanket separation during depressurization. Despite the performance issue, insight into analytical models and MLI construction was gained. Such modeling is important for the effective design of flight vehicle concepts, such as in-space cryogenic depots or in-space cryogenic propulsion stages.

  17. FAVOR: A new fracture mechanics code for reactor pressure vessels subjected to pressurized thermal shock

    International Nuclear Information System (INIS)

    Dickson, T.L.

    1993-01-01

    Probabilistic fracture mechanics (PFM) analysis is a major element of the comprehensive probabilistic methodology endorsed by the Nuclear Regulatory Commission (NRC) for evaluation of the integrity of pressurized water reactor pressure vessels subjected to pressurized-thermal-shock (PTS) transients. OCA-P and VISA-II are PTS PFM computer codes that are currently referenced in Regulatory Guide 1.154 as acceptable codes for performing plant-specific analyses. These codes perform PFM analyses to estimate the increase in vessel failure probability as the vessel accumulates radiation damage over the operating life of the vessel. Experience with the application of these codes in the last few years has provided insights into areas where they could be improved. As more plants approach the PTS screening criteria and are required to perform plant-specific analyses, there will be an increasing need for an improved and validated PTS PFM code that is accepted by the NRC and utilities. The NRC funded Heavy Section Steel Technology Program (HSST) at the Oak Ridge National Laboratory is currently developing the FAVOR (Fracture Analysis of Vessels: Oak Ridge) code, which is expected to meet this need. The FAVOR code incorporates the most important features of both OCA-P and VISA-II and contains some new capabilities such as (1) a PFM global modeling methodology; (2) the calculation of the axial stress component associated with coolant streaming beneath an inlet nozzle; (3) a library of stress intensity factor influence coefficients, generated by the NQA-1 certified ABAQUS computer code, for an appropriate range of two and three dimensional inner-surface flaws; (4) the flexibility to generate a variety of output reports; and (5) enhanced user friendliness

  18. Potential impact of enhanced fracture-toughness data on pressurized-thermal-shock analysis

    International Nuclear Information System (INIS)

    Dickson, T.L.; Theiss, T.J.

    1990-01-01

    The Heavy Section Steel Technology (HSST) Program is involved with the generation of ''enhanced'' fracture-initiation toughness and fracture-arrest toughness data of prototypic nuclear reactor vessel steels. These two sets of data are enhanced because they have distinguishing characteristics that could potentially impact PWR pressure vessel integrity assessments for the pressurized-thermal shock (PTS) loading condition which is a major plant-life extension issue to be confronted in the 1990's. Currently, the HSST Program is planning experiments to verify and quantify, for A533B steel, the distinguishing characteristic of elevated initiation-fracture toughness for shallow flaws which has been observed for other steels. Deterministic and probabilistic fracture-mechanics analyses were performed to examine the influence of the enhanced initiation and arrest fracture-toughness data on the cleavage fracture response of a nuclear reactor pressure vessel subjected to PTS loading. The results of the analyses indicated that application of the enhanced K Ia data does reduce the conditional probability of failure P(F|E); however, it does not appear to have the potential to significantly impact the results of PTS analyses. The application of enhanced fracture-initiation-toughness data for shallow flaws also reduces P(F|E), but it does appear to have a potential for significantly affecting the results of PTS analyses. The effect of including Type I warm prestress in probabilistic fracture-mechanics analyses is beneficial. The benefit is transient dependent and, in some cases, can be quite significant. 19 refs., 12 figs., 1 tab

  19. Verification, validation and application of NEPTUNE-CFD to two-phase Pressurized Thermal Shocks

    Energy Technology Data Exchange (ETDEWEB)

    Mérigoux, N., E-mail: nicolas.merigoux@edf.fr [Electricité de France, R& D Division, 6 Quai Watier, 78401 Chatou (France); Laviéville, J.; Mimouni, S.; Guingo, M.; Baudry, C. [Electricité de France, R& D Division, 6 Quai Watier, 78401 Chatou (France); Bellet, S., E-mail: serge.bellet@edf.fr [Electricité de France, Thermal & Nuclear Studies and Projects Division, 12-14 Avenue Dutriévoz, 69628 Villeurbanne (France)

    2017-02-15

    Nuclear Power Plants are subjected to a variety of ageing mechanisms and, at the same time, exposed to potential Pressurized Thermal Shock (PTS) – characterized by a rapid cooling of the Reactor Pressure Vessel (RPV) wall. In this context, NEPTUNE-CFD is developed and used to model two-phase PTS in an industrial configuration, providing temperature and pressure fields required to assess the integrity of the RPV. Furthermore, when using CFD for nuclear safety demonstration purposes, EDF applies a methodology based on physical analysis, verification, validation and application to industrial scale (V&V), to demonstrate the quality of, and the confidence in results obtained. By following this methodology, each step must be proved to be consistent with the others, and with the final goal of the calculations. To this effect, a chart demonstrating how far the validation step of NEPTUNE-CFD is covering the PTS application will be drawn. A selection of the code verification and validation cases against different experiments will be described. For results consistency, a single and mature set of models – resulting from the knowledge acquired during the code development over the last decade – has been used. From these development and validation feedbacks, a methodology has been set up to perform industrial computations. Finally, the guidelines of this methodology based on NEPTUNE-CFD and SYRTHES coupling – to take into account the conjugate heat transfer between liquid and solid – will be presented. A short overview of the engineering approach will be given – starting from the meshing process, up to the results post-treatment and analysis.

  20. Shock tube experiments on nitromethane and Promotion of chemical reactions by non-thermal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Seljeskog, Morten

    2002-06-01

    This dissertation was undertaken to study two different subjects both related to molecular decomposition by applying a shock tube and non-thermal plasma to decompose selected hydrocarbons. The first approach to molecular decomposition concerned thermal decomposition and oxidation of highly diluted nitromethane (NM) in a shock tube. Reflected shock tube experiments on NM decomposition, using mixtures of 0.2 to 1.5 vol% NM in nitrogen or argon were performed over the temperature range 850-1550 K and pressure range 190-900 kPa, with 46 experiments diluted in nitrogen and 44 diluted in argon. By residual error analysis of the measured decomposition profiles it was found that NM decomposition (CH{sub 3}NO{sub 2} + M {yields} CH{sub 3} + NO{sub 2} + M, where M = N{sub 2} /Ar) corresponds well to a law of first order. Arrhenius expressions corresponding to NM diluted either in N{sub 2} or in Ar were found as k{sub N2} = 10{sup 17.011} * exp(- 182.6 kJ/mole / R*T) and k{sub Ar} = 10{sup 17.574}*exp(-207 kJ/mole / R*T ) , respectively. A new reaction mechanism was then proposed, based on new experimental data for NM decomposition both in Ar and N{sub 2} and on three previously developed mechanisms. The new mechanism predicts well the decomposition of NM diluted in both N{sub 2} and Ar within the pressure and temperature range covered by the experiments. In parallel to, and following the decomposition experiments, oxidative experiments on the ignition delay times of NM/O{sub 2}/Ar mixtures were investigated over high temperature and low to high pressure ranges. These experiments were carried out with eight different mixtures of gaseous NM and oxygen diluted in argon, with pressures ranging between 44.3-600 kPa, and temperatures ranging between 842-1378 K. The oxidation experiments were divided into different categories according to the type of decomposition signals achieved. For signals with and without emission, the apparent quasi

  1. Over-the-road shock and vibration testing of the radioisotope thermoelectric generator transportation system

    International Nuclear Information System (INIS)

    Becker, D.L.

    1997-01-01

    Radioisotope Thermoelectric Generators (RTG) convert heat generated by radioactive decay into electricity through the use of thermocouples. The RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance, which make them particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71 (10 CFR 71). To meet these regulations, a RTG Transportation System (RTGTS) that fully complies with 10 CFR 71 has been developed, which protects RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock, vibration, and heat). To ensure the protection of RTGs from shock and vibration loadings during transport, extensive over-the-road testing was conducted on the RTG'S to obtain real-time recordings of accelerations of the air-ride suspension system trailer floor, packaging, and support structure. This paper provides an overview of the RTG'S, a discussion of the shock and vibration testing, and a comparison of the test results to the specified shock response spectra and power spectral density acceleration criteria

  2. Kinetics of the Thermal Decomposition of Tetramethylsilane behind the Reflected Shock Waves in a Single Pulse Shock Tube (SPST) and Modeling Study

    Science.gov (United States)

    Parandaman, A.; Sudhakar, G.; Rajakumar, B.

    Thermal reactions of Tetramethylsilane (TMS) diluted in argon were studied behind the reflected shock waves in a single-pulse shock tube (SPST) over the temperature range of 1085-1221 K and pressures varied between 10.6 and 22.8 atm. The stable products resulting from the decomposition of TMS were identified and quantified using gas chromatography and also verified with Fourier Transform Infrared (FTIR) spectrometer. The major reaction products are methane (CH4) and ethylene (C2H4). The minor reaction products are ethane (C2H6) and propylene (C3H6). The initiation of mechanism in the decomposition of TMS takes plays via the Si-C bond scission by ejecting the methyl radicals (CH3) and trimethylsilyl radicals ((CH3)3Si). The measured temperature dependent rate coefficient for the total decomposition of TMS was to be ktotal = 1.66 ×1015 exp (-64.46/RT) s-1 and for the formation of CH4 reaction channel was to be k = 2.20 × 1014 exp (-60.15/RT) s-1, where the activation energies are given in kcal mol-1. A kinetic scheme containing 17 species and 28 elementary reactions was used for the simulation using chemical kinetic simulator over the temperature range of 1085-1221 K. The agreement between the experimental and simulated results was satisfactory.

  3. Thermal Shock Experiment (TSEX): a ''proof-of-principle'' evaluation of the use of electron beam heating to simulate the thermal mechanical environment anticipated for the first wall of the Reference Theta-Pinch Reactor (RTPR)

    International Nuclear Information System (INIS)

    Armstrong, P.E.; Krakowski, R.A.

    1977-06-01

    The results of a ''proof-of-principle'' Thermal Shock Experiment (TSEX), designed to simulate the thermal mechanical response of insulator-metal composite first walls anticipated for pulsed high-density fusion reactors, are given. A programmable 10-kV, 1.0-A electron beam was used to pulse repeatedly (0.30-mm)Al 2 O 3 /(1.0-mm) Nb-1Zr composite samples 200 to 300 K, relative to a base-line temperature of 1000 K. The experimental goals of TSEX were established relative to the first-wall environment anticipated for the Reference Theta-Pinch Reactor (RTPR). A detailed description of the TSEX ''proof-of-principle'' apparatus, experimental procedure, and diagnostics is given. The results of extensive thermal analyses are given, which are used to estimate the thermal stresses generated. Although little or no control was exercised over the sample fabrication and thermal history, one sample experienced in excess of 800 thermal cycles of approximately 250 K at approximately 1000 K, and the results of optical and SEM examination of this specimen are presented. The resistance of this sample to macroscopic failure was truly impressive. Recommendations for the construction of an apparatus dedicated to extensive testing of first-wall composites are given on the basis of these ''proof-of-principle'' TSEX results

  4. Estimation of fracture conditions of ceramics by thermal shock with laser beams based on the maximum compressive stress criterion

    International Nuclear Information System (INIS)

    Akiyama, Shigeru; Amada, Shigeyasu.

    1992-01-01

    Structural ceramics are attracting attention in the development of space planes, aircraft and nuclear fusion reactors because they have excellent wear-resistant and heat-resistant characteristics. However, in some applications it is anticipated that they will be exposed to very-high-temperature environments of the order of thousands of degrees. Therefore, it is very important to investigate their thermal shock characteristics. In this report, the distributions of temperatures and thermal stresses of cylindrically shaped ceramics under irradiation by laser beams are discussed using the finite-element computer code (MARC) with arbitrary quadrilateral axisymmetric ring elements. The relationships between spot diameters of laser beams and maximum values of compressive thermal stresses are derived for various power densities. From these relationships, a critical fracture curve is obtained, and it is compared with the experimental results. (author)

  5. Observational test of shock drift and Fermi acceleration on a seed particle population upstream of earth's bow shock

    Science.gov (United States)

    Anagnostopoulos, G. C.; Sarris, E. T.; Krimigis, S. M.

    1988-01-01

    The efficiency of proposed shock acceleration mechanisms as they operate at the bow shock in the presence of a seed energetic particle population was examined using data from simultaneous observations of energetic solar-origin protons, carried out by the IMP 7 and 8 spacecraft in the vicinity of the quasi-parallel (dawn) and quasi-perpendicular (dusk) regions of the earth's bow shock, respectively. The results of observations (which include acceleration effects in the intensities of the energetic protons with energies as high as 4 MeV observed at the vicinity of the dusk bow shock, but no evidence for any particle acceleration at the energy equal to or above 50 keV at the dawn side of the bow shock) indicate that the acceleration of a seed particle population occurs only at the quasi-perpendicular bow shock through shock drift acceleration and that the major source of observed upstream ion populations is the leakage of magnetospheric ions of energies not less than 50 keV, rather than in situ acceleration.

  6. Mechanical properties and thermal shock performance of W-Y2O3 composite prepared by high-energy-rate forging

    Science.gov (United States)

    Lian, Youyun; Liu, Xiang; Feng, Fan; Song, Jiupeng; Yan, Binyou; Wang, Yingmin; Wang, Jianbao; Chen, Jiming

    2017-12-01

    The effects of the addition of Y2O3 and hot-deformation on the mechanical properties of tungsten (W) have been studied. The processing route comprises a doping technique for the distribution of Y2O3 particles in a tungsten matrix, conventional sintering in a hydrogen environment, and high-energy-rate forging (HERF). The microstructure of the composite was characterized by using transmission electron microscopy and electron backscattering diffraction imaging technique, and its mechanical properties were studied by means of tensile testing. The thermal shock response of the HERF processed W-Y2O3 was evaluated by applying edge-localized mode-like loads (100 pulses) with a pulse duration of 1 ms and an absorbed power density of up to 1 GW m-2 at various temperatures between room temperature and 200 °C. HERF processing has produced elongated W grains with preferred orientations and a high density of structure defects in the composite. The composite material exhibits high tensile strength and good ductility, and a thermal shock cracking threshold lower than 100 °C.

  7. Effect of nano-ZrO2 addition on microstructure, mechanical property and thermal shock behaviour of dense chromic oxide refractory material

    International Nuclear Information System (INIS)

    Lu, Lixia; Ding, Chunhui; Zhanga, Chi; Yanga, De'an; Di, Lizhi

    2015-01-01

    To obtain a good performance hot-face lining material in gasifier, nano-ZrO 2 , up to 5 wt %, was added into chromic oxide powder with 3 wt % TiO 2 followed by sintering at 1500°C for 2.5 h. The effect of nano-ZrO 2 addition on microstructure, mechanical property and thermal shock behaviour was studied. ZrO 2 promoted densification at contents higher than 1 wt %. Microcracks and phase transformation toughened the dense chromic oxide refractory material. The main reason for decrease of strength was the existence microcracks in specimens and weakening of intergranular fracture. Dense chromic oxide refractory material with 2∼3 wt % nano-ZrO 2 possessed good densification, uniform microstructure, normal mechanical property and proper thermal shock resistance. The rupture strength retention ratio was nearly twice than that of chromic oxide material without ZrO 2 after three cycles of quenching test from 950°C to cold water. (author)

  8. 40 CFR 91.329 - Catalyst thermal stress test.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress test. 91.329....329 Catalyst thermal stress test. (a) Oven characteristics. The oven used for termally stressing the test catalyst must be capable of maintaining a temperature of 500 ±5 °C and 1000 ±10 °C. (b) Evaluation...

  9. Thermal Shock Tests on UO{sub 2} Small Spheres; Essais de choc thermique sur des elements spheriques de UO{sub 2}; Ispytaniya nebol'shikh sharikov iz UO{sub 2} teplovykh udarom; Ensayo de pequenas esferas de UO{sub 2} por choque.termico

    Energy Technology Data Exchange (ETDEWEB)

    Perona, G.; Brutto, E.; Galbusera, U.; Palladino, G.; Sesini, R. [Centro Informazioni Studi Esperienze, Milan (Italy)

    1963-11-15

    If UO{sub 2} small spheres are used as fuel in a reactor in contact with the cooler, it is necessary to know the maximum value of the thermal stress, due to the work conditions in the reactor, which the small spheres are able to withstand without breaking. These conditions can be calculated if the physical properties of the material are known. Owing to the considerable number of properties involved, and in consideration of the uncertainty which always exists in each of them, it is preferable to test directly the spheres, submitting them to the same kind of stresses that they undergo in thereactor. In this work a thermal shock method for the small spheres has been studied, while conditions are indicated in which this method can reproduce stress conditions directly comparable with those existing in the reactor. As for small spheres, the difficulty consists in producing coolings with very high values of the coefficient of surface heat transfer. The experimental methods are described and the results obtained are indicated. The application of this method seems to be very interesting particularly in the field of the technological research for improving the characteristics of the UO{sub 2} small spheres by means of additives. In fact it allows the control of the total interesting effect with a single measurement. (author) [French] Si l'on veut utiliser comme combustible dans un reacteur des elements spheriques de UO{sub 2} en contact avec le refroidisseur, il faut au prealable determiner la valeur maximum de la contrainte thermique - due aux conditions regnant dans le reacteura laquelle les elements sont capables de resister sans se fissurer. Il est possible de calculer ces conditions si l'on connait les proprietes physiques du materiau utilise. En raison du nombre important des proprietes a prendre en consideration, et compte tenu de l'incertitude qui existe toujours pour chacune d'elles, il est preferable de faire des essais thermiques en soumettant directement les

  10. The probabilistic structural integrity assessment of reactor pressure vessels under pressurized thermal shock loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya, E-mail: chenmingya@cgnpc.com.cn [Suzhou Nuclear Power Research Institute, 215004 Suzhou, Jiangsu Province (China); Lu, Feng; Wang, Rongshan; Yu, Weiwei [Suzhou Nuclear Power Research Institute, 215004 Suzhou, Jiangsu Province (China); Wang, Donghui [State Nuclear Power Plant Service Company, 200237 Shanghai (China); Zhang, Guodong; Xue, Fei [Suzhou Nuclear Power Research Institute, 215004 Suzhou, Jiangsu Province (China)

    2015-12-01

    Highlights: • The methodology and the case study of the FAVOR software were shown. • The over-conservative parameters in the DFM were shown. • The differences between the PFM and the DFM were discussed. • The limits in the current FAVOR were studied. - Abstract: The pressurized thermal shock (PTS) event poses a potentially significant challenge to the structural integrity of the reactor pressure vessel (RPV) during the long time operation (LTO). In the USA, the “screening criteria” for maximum allowable embrittlement of RPV material, which forms part of the USA regulations, is based on the probabilistic fracture mechanics (PFM). The FAVOR software developed by Oak Ridge National Laboratory (ORNL) is used to establish the regulation. As the technical basis of FAVOR is not the most widely-used and codified methodologies, such as the ASME and RCC-M codes, in most countries (with exception of the USA), proving RPV integrity under the PTS load is still based on the deterministic fracture mechanics (DFM). As the maximum nil-ductility-transition temperature (RT{sub NDT}) of the beltline material for the 54 French RPVs after 40 years operation is higher than the critical values in the IAEA-TECDOC-1627 and European NEA/CSNI/R(99)3 reports (while still obviously lower than the “screening criteria” of the USA), it may conclude that the RPV will not be able to run in the LTO based on the DFM. In the FAVOR, the newest developments of fracture mechanics are applied, such as the warm pre-stress (WPS) effect, more accurate estimation of the flaw information and less conservation of the toughness (such as the three-parameter Weibull distribution of the fracture toughness). In this paper, the FAVOR software is first applied to show both the methodology and the results of the PFM, and then the limits in the current FAVOR software (Version 6.1, which represents the baseline for re-assessing the regulation of 10 CFR 50.61), lack of the impact of the constraint effect

  11. Power Control and Monitoring Requirements for Thermal Vacuum/Thermal Balance Testing of the MAP Observatory

    Science.gov (United States)

    Johnson, Chris; Hinkle, R. Kenneth (Technical Monitor)

    2002-01-01

    The specific heater control requirements for the thermal vacuum and thermal balance testing of the Microwave Anisotropy Probe (MAP) Observatory at the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland are described. The testing was conducted in the 10m wide x 18.3m high Space Environment Simulator (SES) Thermal Vacuum Facility. The MAP thermal testing required accurate quantification of spacecraft and fixture power levels while minimizing heater electrical emissions. The special requirements of the MAP test necessitated construction of five (5) new heater racks.

  12. Test of a new heat-flow equation for dense-fluid shock waves.

    Science.gov (United States)

    Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

    2010-09-21

    Using a recently proposed equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, we model shockwave propagation in the dense Lennard-Jones fluid. Disequilibrium among the three components of temperature, namely, the difference between the kinetic temperature in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, gives rise to a new transport (equilibration) mechanism not seen in usual one-dimensional heat-flow situations. The modification of the heat-flow equation was tested earlier for the case of strong shock waves in the ideal gas, which had been studied in the past and compared to Navier-Stokes-Fourier solutions. Now, the Lennard-Jones fluid, whose equation of state and transport properties have been determined from independent calculations, allows us to study the case where potential, as well as kinetic contributions are important. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations under strong shock wave conditions, compared to Navier-Stokes.

  13. Assessment of margins with respect to pressurized thermal shock for the 3 loop plants of the French program

    International Nuclear Information System (INIS)

    Buchalet, C.; Haussaire, P.; Houssin, B.; Vagner, J.

    1983-08-01

    Presentation of the FRAMATOME and EDF program on pressurized thermal shock which objectives are to demonstrate that present and older French reactor vessels have adequate safety margins and to provide recommendations of feasible plant specific modifications, both technically and economically. Phase I consists in a thorough analysis of pressure and temperature transients that the R.P.V. beltine could undergo during plant operations; phase II is the fracture mechanics analysis; phase III estimates the safety margins available during normal, upset, emergency and faulted conditions

  14. Thermal cycling tests of actively cooled beryllium copper joints

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, M.; Duwe, R.; Linke, J.; Schuster, A.; Wiechers, B. [Forschungszentrum Juelich GmbH (Germany)

    1998-01-01

    Screening tests (steady state heating) and thermal fatigue tests with several kinds of beryllium-copper joints have been performed in an electron beam facility. Joining techniques under investigation were brazing with silver containing and silver-free braze materials, hot isostatic pressing (HIP) and diffusion bonding (hot pressing). Best thermal fatigue performance was found for the brazed samples. (author)

  15. Electrical, thermal and abusive tests on lithium thionyl chloride cells

    Science.gov (United States)

    Frank, H. A.

    1980-04-01

    Electrical characterizations, thermal characterizations, and outer limits tests of lithium thionyl chloride cells are discussed. Graphs of energy density vs power density and heat rate vs time are presented along with results of forced reversal and high rate discharge tests.

  16. Comparison report of RPV pressurised thermal shock - international comparative assessment study (PTS ICAS)

    International Nuclear Information System (INIS)

    1999-01-01

    A summary of the recently completed International Comparative Assessment Study of Pressurized- Thermal-Shock in Reactor Pressure Vessels (RPV PTS ICAS) is presented here to record the results in actual and comparative fashions. The ICAS Project brought together an international group of experts from research, utility and regulatory organizations to perform a comparative evaluation of analysis methodologies employed in the assessment of RPV integrity under PTS loading conditions. The Project was sponsored jointly by Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS), Koeln, Germany, and Oak Ridge National Laboratory (ORNL), USA, with assistance from the Organization for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA)/Committee on the Safety of Nuclear Installations (CSNI)/Principal Working Group (PWG) No. 3 (Integrity of Components and Structures). The ICAS Project grew out of a strong interest expressed by participants in the previous FALSIRE II Project to proceed with further evaluations of analysis methods used in RPV integrity assessment. A Launch Meeting for the ICAS Project was held at GRS-Koeln, during June 1996, where an emphasis was placed on identifying the different approaches to RPV integrity assessment being employed within the international nuclear technology community. Also a Problem Statement was drafted that defined a Western type four-loop RPV with cladding on the inner surface. Also, a detailed task matrix was defined that included a set of transient thermal-mechanical loading conditions postulated to result from loss-of-coolant accidents. The primary focus of the analyses was on the behaviour of relatively shallow cracks under these conditions. The assessment activities based on the Problem Statement were divided under three tasks: deterministic fracture mechanics (DFM), probabilistic fracture mechanics (PFM) and thermal-hydraulic mixing (THM). An Intermediate Workshop was held at OECD/NEA-Paris during June 1997, to

  17. Thermal tests of a transport / Storage cask in buried conditions

    International Nuclear Information System (INIS)

    Yamakawa, H.; Gomi, Y.; Saegusa, T.; Ito, C.

    1998-01-01

    Thermal tests for a hypothetical accident which simulated accidents caused by building collapse in case of an earthquake were conducted using a full-scale dry type transport and storage cask (total heat load: 23 kW). The objectives of these tests were to clarify the heat transfer features of the buried cask under such accidents and the time limit for maintaining the thermal integrity of the cask. Moreover, thermal analyses of the test cask under the buried conditions were carried out on basis of experimental results to establish methodology for the thermal analysis. The characteristics of the test cask are described as well as the test method used. The heat transfer features of the buried cask under such accidents and a time for maintaining the thermal integrity of the cask have been obtained. (O.M.)

  18. Stochastic shock response spectrum decomposition method based on probabilistic definitions of temporal peak acceleration, spectral energy, and phase lag distributions of mechanical impact pyrotechnic shock test data

    Science.gov (United States)

    Hwang, James Ho-Jin; Duran, Adam

    2016-08-01

    Most of the times pyrotechnic shock design and test requirements for space systems are provided in Shock Response Spectrum (SRS) without the input time history. Since the SRS does not describe the input or the environment, a decomposition method is used to obtain the source time history. The main objective of this paper is to develop a decomposition method producing input time histories that can satisfy the SRS requirement based on the pyrotechnic shock test data measured from a mechanical impact test apparatus. At the heart of this decomposition method is the statistical representation of the pyrotechnic shock test data measured from the MIT Lincoln Laboratory (LL) designed Universal Pyrotechnic Shock Simulator (UPSS). Each pyrotechnic shock test data measured at the interface of a test unit has been analyzed to produce the temporal peak acceleration, Root Mean Square (RMS) acceleration, and the phase lag at each band center frequency. Maximum SRS of each filtered time history has been calculated to produce a relationship between the input and the response. Two new definitions are proposed as a result. The Peak Ratio (PR) is defined as the ratio between the maximum SRS and the temporal peak acceleration at each band center frequency. The ratio between the maximum SRS and the RMS acceleration is defined as the Energy Ratio (ER) at each band center frequency. Phase lag is estimated based on the time delay between the temporal peak acceleration at each band center frequency and the peak acceleration at the lowest band center frequency. This stochastic process has been applied to more than one hundred pyrotechnic shock test data to produce probabilistic definitions of the PR, ER, and the phase lag. The SRS is decomposed at each band center frequency using damped sinusoids with the PR and the decays obtained by matching the ER of the damped sinusoids to the ER of the test data. The final step in this stochastic SRS decomposition process is the Monte Carlo (MC

  19. Shock-induced thermal wave propagation and response analysis of a viscoelastic thin plate under transient heating loads

    Science.gov (United States)

    Li, Chenlin; Guo, Huili; Tian, Xiaogeng

    2018-04-01

    This paper is devoted to the thermal shock analysis for viscoelastic materials under transient heating loads. The governing coupled equations with time-delay parameter and nonlocal scale parameter are derived based on the generalized thermo-viscoelasticity theory. The problem of a thin plate composed of viscoelastic material, subjected to a sudden temperature rise at the boundary plane, is solved by employing Laplace transformation techniques. The transient responses, i.e. temperature, displacement, stresses, heat flux as well as strain, are obtained and discussed. The effects of time-delay and nonlocal scale parameter on the transient responses are analyzed and discussed. It can be observed that: the propagation of thermal wave is dynamically smoothed and changed with the variation of time-delay; while the displacement, strain, and stress can be rapidly reduced by nonlocal scale parameter, which can be viewed as an important indicator for predicting the stiffness softening behavior for viscoelastic materials.

  20. Test facilities for evaluating nuclear thermal propulsion systems

    International Nuclear Information System (INIS)

    Beck, D.F.; Allen, G.C.; Shipers, L.R.; Dobranich, D.; Ottinger, C.A.; Harmon, C.D.; Fan, W.C.; Todosow, M.

    1992-01-01

    Interagency panels evaluating nuclear thermal propulsion (NTP) development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and baseline performance of some of the major subsystems designed to support a proposed ground test complex for evaluating nuclear thermal propulsion fuel elements and engines being developed for the Space Nuclear Thermal Propulsion (SNTP) program. Some preliminary results of evaluating this facility for use in testing other NTP concepts are also summarized

  1. Two-phase pressurized thermal shock investigations using a 3D two-fluid modeling of stratified flow with condensation

    International Nuclear Information System (INIS)

    Yao, W.; Coste, P.; Bestion, D.; Boucker, M.

    2003-01-01

    In this paper, a local 3D two-fluid model for a turbulent stratified flow with/without condensation, which can be used to predict two-phase pressurized thermal shock, is presented. A modified turbulent K- model is proposed with turbulence production induced by interfacial friction. A model of interfacial friction based on a interfacial sublayer concept and three interfacial heat transfer models, namely, a model based on the small eddies controlled surface renewal concept (HDM, Hughes and Duffey, 1991), a model based on the asymptotic behavior of the Eddy Viscosity (EVM), and a model based on the Interfacial Sublayer concept (ISM) are implemented into a preliminary version of the NEPTUNE code based on the 3D module of the CATHARE code. As a first step to apply the above models to predict the two-phase thermal shock, the models are evaluated by comparison of calculated profiles with several experiments: a turbulent air-water stratified flow without interfacial heat transfer; a turbulent steam-water stratified flow with condensation; turbulence induced by the impact of a water jet in a water pool. The prediction results agree well with the experimental data. In addition, the comparison of three interfacial heat transfer models shows that EVM and ISM gave better prediction results while HDM highly overestimated the interfacial heat transfers compared to the experimental data of a steam water stratified flow

  2. The effect of thermal shock on morphological characteristics of blood cells in Siberian sturgeon (Acipenser baerii triploids

    Directory of Open Access Journals (Sweden)

    Teresa Wlasow

    2011-01-01

    Full Text Available The aim of the study was to evaluate the effect of thermal shock on morphotic blood elements in Siberian sturgeon Acipenser baerii triploids. The thermal shock (37 °C for 2 min was applied in the 18th min after fertilization. Blood was sampled from parallel cultured ten triploids and ten diploids on day 70 after hatching. Ploidy was assessed with the cytogenetic method and measurements of cellular nuclei. In the blood of triploids, significant dominance of immature red blood cells, erythrocytes with a displaced nucleus, microcytes and erythroplastids were observed. The blood of triploids was also characterized by a reduced number of lymphocytes. The percentage of neutrophil and eosinophil granulocytes was elevated; increased share of neutrophil granulocytes with a 4-, 5- or 6-segmented nucleus and eosinophil granulocytes with a nucleus consisting of three and more segments was observed. Disturbances in the picture of red blood cells can be considered as an expression of intensification of end-stage changes in triploids. The response to these changes in the blood of triploid Siberian sturgeon is an increase in the share of polymorphonuclear PMN, cells counted as microphages. Frequent presence of immature red blood cells in triploid Siberian sturgeon is a process that aims at counterbalancing the loss among these blood cells. It is the first report on morphological changes and proportions among blood cells in triploid Siberian sturgeon.

  3. Effect of long-term water immersion or thermal shock on mechanical properties of high-impact acrylic denture base resins.

    Science.gov (United States)

    Sasaki, Hirono; Hamanaka, Ippei; Takahashi, Yutaka; Kawaguchi, Tomohiro

    2016-01-01

    The purpose of this study was to investigate the effect of long-term water immersion or thermal shock on the mechanical properties of high-impact acrylic denture base resins. Two high-impact acrylic denture base resins were selected for the study. Specimens of each denture base material tested were fabricated according to the manufacturers' instructions (n=10). The flexural strength at the proportional limit, the elastic modulus and the impact strength of the specimens were evaluated. The flexural strength at the proportional limit of the high-impact acrylic denture base resins did not change after six months' water immersion or thermocycling 50,000 times. The elastic moduli of the high-impact acrylic denture base resins significantly increased after six months' water immersion or thermocycling 50,000 times. The impact strengths of the high-impact acrylic denture base resins significantly decreased after water immersion or thermocycling as described above.

  4. Thermal reactor benchmark tests on JENDL-2

    International Nuclear Information System (INIS)

    Takano, Hideki; Tsuchihashi, Keichiro; Yamane, Tsuyoshi; Akino, Fujiyoshi; Ishiguro, Yukio; Ido, Masaru.

    1983-11-01

    A group constant library for the thermal reactor standard nuclear design code system SRAC was produced by using the evaluated nuclear data JENDL-2. Furthermore, the group constants for 235 U were calculated also from ENDF/B-V. Thermal reactor benchmark calculations were performed using the produced group constant library. The selected benchmark cores are two water-moderated lattices (TRX-1 and 2), two heavy water-moderated cores (DCA and ETA-1), two graphite-moderated cores (SHE-8 and 13) and eight critical experiments for critical safety. The effective multiplication factors and lattice cell parameters were calculated and compared with the experimental values. The results are summarized as follows. (1) Effective multiplication factors: The results by JENDL-2 are considerably improved in comparison with ones by ENDF/B-IV. The best agreement is obtained by using JENDL-2 and ENDF/B-V (only 235 U) data. (2) Lattice cell parameters: For the rho 28 (the ratio of epithermal to thermal 238 U captures) and C* (the ratio of 238 U captures to 235 U fissions), the values calculated by JENDL-2 are in good agreement with the experimental values. The rho 28 (the ratio of 238 U to 235 U fissions) are overestimated as found also for the fast reactor benchmarks. The rho 02 (the ratio of epithermal to thermal 232 Th captures) calculated by JENDL-2 or ENDF/B-IV are considerably underestimated. The functions of the SRAC system have been continued to be extended according to the needs of its users. A brief description will be given, in Appendix B, to the extended parts of the SRAC system together with the input specification. (author)

  5. JENDL-3.3 thermal reactor benchmark test

    International Nuclear Information System (INIS)

    Akie, Hiroshi

    2001-01-01

    Integral tests of JENDL-3.2 nuclear data library have been carried out by Reactor Integral Test WG of Japanese Nuclear Data Committee. The most important problem in the thermal reactor benchmark testing was the overestimation of the multiplication factor of the U fueled cores. With several revisions of the data of 235 U and the other nuclides, JENDL-3.3 data library gives a good estimation of multiplication factors both for U and Pu fueled thermal reactors. (author)

  6. COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. I. NEUTRAL RETURN FLUX AND ITS EFFECTS ON ACCELERATION OF TEST PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Blasi, P.; Morlino, G.; Bandiera, R.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125 Firenze (Italy); Caprioli, D. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08540 (United States)

    2012-08-20

    A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high-velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, which we refer to as the neutral return flux, is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge-exchange interaction lengths of fast neutrals moving toward upstream infinity. In the case of a shock propagating in the interstellar medium, the effects of ion-neutral interactions are especially important for shock velocities <3000 km s{sup -1}. Such propagation velocities are common among shocks associated with supernova remnants, the primary candidate sources for the acceleration of Galactic cosmic rays. We then investigate the effects of the return flux of neutrals on the spectrum of test particles accelerated at the shock. We find that, for shocks slower than {approx}3000 km s{sup -1}, the particle energy spectrum steepens appreciably with respect to the naive expectation for a strong shock, namely, {proportional_to}E{sup -2}.

  7. Thermal and Alignment Analysis of the Instrument-Level ATLAS Thermal Vacuum Test

    Science.gov (United States)

    Bradshaw, Heather

    2012-01-01

    This paper describes the thermal analysis and test design performed in preparation for the ATLAS thermal vacuum test. NASA's Advanced Topographic Laser Altimeter System (ATLAS) will be flown as the sole instrument aboard the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2). It will be used to take measurements of topography and ice thickness for Arctic and Antarctic regions, providing crucial data used to predict future changes in worldwide sea levels. Due to the precise measurements ATLAS is taking, the laser altimeter has very tight pointing requirements. Therefore, the instrument is very sensitive to temperature-induced thermal distortions. For this reason, it is necessary to perform a Structural, Thermal, Optical Performance (STOP) analysis not only for flight, but also to ensure performance requirements can be operationally met during instrument-level thermal vacuum testing. This paper describes the thermal model created for the chamber setup, which was used to generate inputs for the environmental STOP analysis. This paper also presents the results of the STOP analysis, which indicate that the test predictions adequately replicate the thermal distortions predicted for flight. This is a new application of an existing process, as STOP analyses are generally performed to predict flight behavior only. Another novel aspect of this test is that it presents the opportunity to verify pointing results of a STOP model, which is not generally done. It is possible in this case, however, because the actual pointing will be measured using flight hardware during thermal vacuum testing and can be compared to STOP predictions.

  8. Fracture mechanics analysis of reactor pressure vessel under pressurized thermal shock - The effect of elastic-plastic behavior and stainless steel cladding -

    International Nuclear Information System (INIS)

    Joo, Jae Hwang; Kang, Ki Ju; Jhung, Myung Jo

    2002-01-01

    Performed here is an assessment study for deterministic fracture mechanics analysis of a pressurized thermal shock (PTS). The PTS event means an event or transient in pressurized water reactors (PWRs) causing severe overcooling (thermal shock) concurrent with or followed by significant pressure in the reactor vessel. The problems consisting of two transients and 10 cracks are solved and maximum stress intensity factors and maximum allowable nil-ductility reference temperatures are calculated. Their results are compared each other to address the general characteristics between transients, crack types and analysis methods. The effects of elastic-plastic material behavior and clad coating on the inner surface are explored

  9. Reflection of a shock wave from a thermally accommodating wall - Molecular simulation.

    Science.gov (United States)

    Deiwert, G. S.

    1973-01-01

    Reflection of a plane shock wave from a wall has been simulated on a microscopic scale using a direct simulation Monte Carlo technique of the type developed by Bird. A monatomic gas model representing argon was used to describe the fluid medium and a simple one-parameter accommodation coefficient model was used to describe the gas-surface interaction. The influence of surface accommodation was studied parametrically by varying the accommodation coefficient from zero to one. Results are presented showing the temporal variations of flow field density, and mass, momentum, and energy fluxes to the wall during the shock wave reflection process. The energy flux was used to determine the wall temperature history. Comparisons with experiment are found to be satisfactory where data are available.

  10. Thermal Shock In Periodic Edge-Cracked Plate Supported By Elastic Foundation

    OpenAIRE

    Abd El-Fattah A. Rizk

    2012-01-01

    The study of the transient thermal stress problem for a periodic edge cracks in an elastic plate on an elastic foundations is investigated. This study may also be applied for circumferentially periodic cracked hollow cylinder under transient thermal stresses. Based on previous studies, the cylindrical shell may be modeled by a plate on an elastic foundation. The thermal stresses are generated due to sudden convective cooling on the boundary containing the edge cracks while the other boundary ...

  11. Thermal Hydraulic Integral Effect Tests for Pressurized Water Reactors

    International Nuclear Information System (INIS)

    Baek, Won Pil; Song, C. H.; Kim, Y. S.

    2007-02-01

    The objectives of the project are to construct a thermal-hydraulic integral effect test facility and to perform the tests for design, operation, and safety regulation of pressurized water reactors. In the first phase of this project (1997.8∼2002.3), the basic technology for thermal-hydraulic integral effect tests was established and the basic design of the test facility was accomplished. In the second phase (2002.4∼2005.2), an optimized design of the ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) was established and the construction of the facility was almost completed. In the third phase (2005.3∼2007.2), the construction and commission tests of the ATLAS are to be completed and some first-phase tests are to be conducted

  12. Performance testing of thermal analysis codes for nuclear fuel casks

    International Nuclear Information System (INIS)

    Sanchez, L.C.

    1987-01-01

    In 1982 Sandia National Laboratories held the First Industry/Government Joint Thermal and Structural Codes Information Exchange and presented the initial stages of an investigation of thermal analysis computer codes for use in the design of nuclear fuel shipping casks. The objective of the investigation was to (1) document publicly available computer codes, (2) assess code capabilities as determined from their user's manuals, and (3) assess code performance on cask-like model problems. Computer codes are required to handle the thermal phenomena of conduction, convection and radiation. Several of the available thermal computer codes were tested on a set of model problems to assess performance on cask-like problems. Solutions obtained with the computer codes for steady-state thermal analysis were in good agreement and the solutions for transient thermal analysis differed slightly among the computer codes due to modeling differences

  13. Oxygen Containment System Options for Nuclear Thermal Propulsion Testing

    Data.gov (United States)

    National Aeronautics and Space Administration — All nuclear thermal propulsion (NTP) ground testing conducted in the 1950s and 1960s during the ROVER/(Nuclear Engine Rocket Vehicle Application (NERVA) program...

  14. Multi-scale modelling of thermal shock damage in refractory materials

    NARCIS (Netherlands)

    Özdemir, I.

    2009-01-01

    Refractories are high-temperature resistant materials used extensively in many engineering structures and assemblies in a wide spectrum of applications ranging from metallurgical furnace linings to thermal barrier coatings. Such structures are often exposed to severe thermal loading conditions in

  15. Radioisotope Thermoelectric Generator Transporation System licensed hardware second certification test series and package shock mount system test

    International Nuclear Information System (INIS)

    Ferrell, P.C.; Moody, D.A.

    1995-10-01

    This paper presents a summary of two separate drop test a e performed in support of the Radioisotope Thermoelectric Generator (RTG) Transportation System (RTGTS). The first portion of this paper presents the second series of drop testing required to demonstrate that the RTG package design meets the requirements of Title 10, Code of Federal Regulations, ''Part 71'' (10 CFR 71). Results of the first test series, performed in July 1994, demonstrated that some design changes were necessary. The package design was modified to improve test performance and the design changes were incorporated into the Safety Analysis Report for Packaging (SARP). The second full-size certification test article (CTA-2) incorporated the modified design and was tested at the US Department of Energy's (DOE) Hanford Site near Richland, Washington. With the successful completion of the test series, and pending DOE Office of Facility Safety Analysis approval of the SARP, a certificate of compliance will be issued for the RTG package allowing its use. The second portion of this paper presents the design and testing of the RTG Package Mount System. The RTG package mount was designed to protect the RTG from excessive vibration during transport, provide shock protection during on/off loading, and provide a mechanism for moving the RTG package with a forklift. Military Standard (MIL-STD) 810E, Transit Drop Procedure (DOE 1989), was used to verify that the shock limiting system limited accelerations in excess of 15 G's at frequencies below 150 Hz. Results of the package mount drop tests indicate that an impact force of 15 G's was not exceeded in any test from a free drop height of 457 mm (18 in.)

  16. Thermal Hydraulic Integral Effect Tests for Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Baek, W. P.; Song, C. H.; Kim, Y. S. and others

    2005-02-15

    The objectives of the project are to construct a thermal-hydraulic integral effect test facility and to perform various integral effect tests for design, operation, and safety regulation of pressurized water reactors. During the first phase of this project (1997.8{approx}2002.3), the basic technology for thermal-hydraulic integral effect tests was established and the basic design of the test facility was accomplished: a full-height, 1/300-volume-scaled full pressure facility for APR1400, an evolutionary pressurized water reactor that was developed by Korean industry. Main objectives of the present phase (2002.4{approx}2005.2), was to optimize the facility design and to construct the experimental facility. We have performed following researches: 1) Optimization of the basic design of the thermal-hydraulic integral effect test facility for PWRs - ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation) - Reduced height design for APR1400 (+ specific design features of KSNP safety injection systems) - Thermal-hydraulic scaling based on three-level scaling methodology by Ishii et al. 2) Construction of the ATLAS facility - Detailed design of the test facility - Manufacturing and procurement of components - Installation of the facility 3) Development of supporting technology for integral effect tests - Development and application of advanced instrumentation technology - Preliminary analysis of test scenarios - Development of experimental procedures - Establishment and implementation of QA system/procedure.

  17. IBL Thermal Mockup Bake-Out Tests

    CERN Document Server

    Nuiry, FX

    2014-01-01

    This note summarizes different bake-out tests that have been performed with the ATLAS Insertable B-Layer (IBL) mockup. Two beam pipe configurations have been tested: one with the aerogel insulation layer all along the pipe and one without insulation over 622 mm around Z0. These tests have been crucial for decisions about aerogel removal, choice of heaters for the LHC beam pipe bake-out, and choice of temperature setpoints for the cooling system during nominal IBL operation. They also revealed very useful information on integration issues and the thermo-mechanical behaviour of the IBL detector.

  18. Thermal conductivity tests on buffermasses of bentonite/silt

    International Nuclear Information System (INIS)

    Knutsson, S.

    1977-09-01

    The investigation concerns the thermal conductivity of the bentonite/quartz buffer mass suggested as embedding substance for radioactive canisters. The first part presents the theoretical relationships associated with the various heat transfer mechanisms in moist granular materials. Chapter 3 describes the author's experimental determination of the thermal conductivity of the buffer mass. The tested mass consisted of 10 percent (by weight) bentonite and 90 percent natural silt. Four tests were made with different water content values and degree of water saturation. A comparison between the measured and calculated thermal conductivities is given. It is shown that the conductivity can be calculated with an accuracy of +-20 percent. (author)

  19. Pretest Calculations of Temperature Changes for Field Thermal Conductivity Tests

    International Nuclear Information System (INIS)

    N.S. Brodsky

    2002-01-01

    A large volume fraction of the potential monitored geologic repository at Yucca Mountain may reside in the Tptpll (Tertiary, Paintbrush Group, Topopah Spring Tuff, crystal poor, lower lithophysal) lithostratigraphic unit. This unit is characterized by voids, or lithophysae, which range in size from centimeters to meters. A series of thermal conductivity field tests are planned in the Enhanced Characterization of the Repository Block (ECRB) Cross Drift. The objective of the pretest calculation described in this document is to predict changes in temperatures in the surrounding rock for these tests for a given heater power and a set of thermal transport properties. The calculation can be extended, as described in this document, to obtain thermal conductivity, thermal capacitance (density x heat capacity, J · m -3 · K -1 ), and thermal diffusivity from the field data. The work has been conducted under the ''Technical Work Plan For: Testing and Monitoring'' (BSC 2001). One of the outcomes of this analysis is to determine the initial output of the heater. This heater output must be sufficiently high that it will provide results in a reasonably short period of time (within several weeks or a month) and be sufficiently high that the heat increase is detectable by the instruments employed in the test. The test will be conducted in stages and heater output will be step increased as the test progresses. If the initial temperature is set too high, the experiment will not have as many steps and thus fewer thermal conductivity data points will result

  20. Thermal testing of packages for transport of radioactive wastes

    International Nuclear Information System (INIS)

    Koski, J.A.

    1994-01-01

    Shipping containers for radioactive materials must be shown capable of surviving tests specified by regulations such as Title 10, Code of Federal Regulations, Part 71 (called 10CFR71 in this paper) within the United States. Equivalent regulations hold for other countries such as Safety Series 6 issued by the International Atomic Energy Agency. The containers must be shown to be capable of surviving, in order, drop tests, puncture tests, and thermal tests. Immersion testing in water is also required, but must be demonstrated for undamaged packages. The thermal test is intended to simulate a 30 minute exposure to a fully engulfing pool fire that could occur if a transport accident involved the spill of large quantities of hydrocarbon fuels. Various qualification methods ranging from pure analysis to actual pool fire tests have been used to prove regulatory compliance. The purpose of this paper is to consider the alternatives for thermal testing, point out the strengths and weaknesses of each approach, and to provide the designer with the information necessary to make informed decisions on the proper test program for the particular shipping container under consideration. While thermal analysis is an alternative to physical testing, actual testing is often emphasized by regulators, and this report concentrates on these testing alternatives

  1. Thermal Analysis of Bending Under Tension Test

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Martins, Paulo A.F.; Bay, Niels

    2014-01-01

    during testing is similar to the one in the production tool. A universal sheet tribo-tester has been developed, which can run multiple tests automatically from coil. This allows emulating the temperature increase as in production. The present work performs finite element analysis of the evolution......The tribological conditions in deep drawing can be simulated in the Bending Under Tension test to evaluate the performance of new lubricants, tool materials, etc. Deep drawing production with automatic handling runs normally at high rate. This implies considerable heating of the tools, which...... sometimes can cause lubricant film breakdown and galling. In order to replicate the production conditions in bending under tension testing it is thus important to control the tool/workpiece interface temperature. This can be done by pre-heating the tool, but it is essential that the interface temperature...

  2. Prognostic value of brachioradialis muscle oxygen saturation index and vascular occlusion test in septic shock patients.

    Science.gov (United States)

    Marín-Corral, J; Claverias, L; Bodí, M; Pascual, S; Dubin, A; Gea, J; Rodriguez, A

    2016-05-01

    To compare rSO2 (muscle oxygen saturation index) static and dynamic variables obtained by NIRS (Near Infrared Spectroscopy) in brachioradialis muscle of septic shock patients and its prognostic implications. Prospective and observational study. Intensive care unit. Septic shock patients and healthy volunteers. The probe of a NIRS device (INVOS 5100) was placed on the brachioradialis muscle during a vascular occlusion test (VOT). Baseline, minimum and maximum rSO2 values, deoxygenation rate (DeOx), reoxygenation slope (ReOx) and delta value. Septic shock patients (n=35) had lower baseline rSO2 (63.8±12.2 vs. 69.3±3.3%, p<0.05), slower DeOx (-0.54±0.31 vs. -0.91±0.35%/s, p=0.001), slower ReOx (2.67±2.17 vs. 9.46±3.5%/s, p<0.001) and lower delta (3.25±5.71 vs. 15.1±3.9%, p<0.001) when compared to healthy subjects (n=20). Among septic shock patients, non-survivors showed lower baseline rSO2 (57.0±9.6 vs. 69.8±11.3%, p=0.001), lower minimum rSO2 (36.0±12.8 vs. 51.3±14.8%, p<0.01) and lower maximum rSO2 values (60.6±10.6 vs. 73.3±11.2%, p<0.01). Baseline rSO2 was a good mortality predictor (AUC 0.79; 95%CI: 0.63-0.94, p<0.01). Dynamic parameters obtained with VOT did not improve the results. Septic shock patients present an important alteration of microcirculation that can be evaluated by NIRS with prognostic implications. Monitoring microvascular reactivity in the brachioradialis muscle using VOT with our device does not seem to improve the prognostic value of baseline rSO2. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  3. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-10-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable␣interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  4. Thermal Shock Properties of Cladding with SiC{sub f}/SiC Composite Protective Films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Donghee; Park, Kwangheon [Kyunghee University, Yongin (Korea, Republic of); Kim, Weonju; Park, Jiyeon; Kim, Daejong; Lee, Hyeon Geun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    In general, Zr-4 alloy is used for such nuclear fuel cladding. Zr-4 possesses a very small thermal neutron absorption cross-section and has superior corrosion resistance in the normal operating conditions of a nuclear reactor. However, in the case of a critical accident such as a LOCA (loss-of-coolant accident) in the Fukushima disaster, the risk of hydrogen explosion becomes serious. That is, in the case of coolant leakage, a dramatic reaction between the nuclear fuel cladding and steam can cause a heating reaction accompanied by rapid high-temperature oxidation, while creating a huge amount of hydrogen. Hence, the search for an alternative material for nuclear fuel cladding is being actively undertaken. Ceramic-based nuclear fuel cladding is receiving much attention as a means of improving safety. SiC has excellent properties of resistance to high temperature and high exposure and superior mechanical properties, as well as a very small thermal neutron absorption cross-section (0.09 barns), which causes almost no decrease in mechanical strength or volume change following exposure. This experiment examined the thermal shock properties and microstructure of cladding that has SiCf/SiC composite protective film, using polycarbosilane preceramic polymer.

  5. Thermal Vacuum Test Correlation of a Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytical Model

    Science.gov (United States)

    Mckim, Stephen A.

    2016-01-01

    This thesis describes the development and correlation of a thermal model that forms the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented are presented. The thermal model was correlated to within plus or minus 3 degrees Celsius of the thermal vacuum test data, and was determined sufficient to make future propellant predictions on MMS. The model was also found to be relatively sensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed to improve temperature predictions in the upper hemisphere of the propellant tank where predictions were found to be 2 to 2.5 C lower than the test data. A road map for applying the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

  6. Effect of Thermal Shock During Legionella Bacteria Removal on the Corrosion Properties of Zinc-Coated Steel Pipes

    Science.gov (United States)

    Orlikowski, Juliusz; Ryl, Jacek; Jazdzewska, Agata; Krakowiak, Stefan

    2016-07-01

    The purpose of this investigation was to conduct the failure analysis of a water-supply system made from zinc-coated steel. The observed corrosion process had an intense and complex character. The brownish deposits and perforations were present after 2-3 years of exploitation. The electrochemical study based on the Tafel polarization, corrosion potential monitoring, and electrochemical impedance spectroscopy together with microscopic analysis via SEM and EDX were performed in order to identify the cause of such intense corrosion. The performed measurements allowed us to determine that thermal shock was the source of polarity-reversal phenomenon. This process had begun the corrosion of steel which later led to the formation of deposits and perforations in the pipes. The work includes appropriate action in order to efficiently identify the described corrosion threat.

  7. Stress intensity factors for underclad and through clad defects in a reactor pressure vessel submitted to a pressurised thermal shock

    International Nuclear Information System (INIS)

    Marie, S.; Menager, Y.; Chapuliot, S.

    2005-01-01

    CEA has launched important work on the development of a Stress Intensity Factors compendium for cracks in a Reactor Pressure Vessel (RPV) taking into account the cladding. The work is performed by Finite Element analysis with a parametric mesh for two types of defects (under clad defect and through clad defect) and a wide range of geometrical and material parameters. In addition, an analytical stress solution for Pressurised Thermal Shock (PTS) on the RPV is proposed to allow a complete analytical estimation of the stress intensity factor K I for the PTS problem. The results are validated by comparison with a complete 3D finite element calculation performed on a complex and realistic case study

  8. Testing for Nuclear Thermal Propulsion Systems: Identification of Technologies for Effluent Treatment in Test Facilities

    Data.gov (United States)

    National Aeronautics and Space Administration — Key steps to ensure identification of relevant effluent treatment technologies for Nuclear Thermal Propulsion (NTP) testing include the following. 1. Review of...

  9. Numerical thermal mathematical model correlation to thermal balance test using adaptive particle swarm optimization (APSO)

    International Nuclear Information System (INIS)

    Beck, T.; Bieler, A.; Thomas, N.

    2012-01-01

    We present structural and thermal model (STM) tests of the BepiColombo laser altimeter (BELA) receiver baffle with emphasis on the correlation of the data with a thermal mathematical model. The test unit is a part of the thermal and optical protection of the BELA instrument being tested under infrared and solar irradiation at University of Bern. An iterative optimization method known as particle swarm optimization has been adapted to adjust the model parameters, mainly the linear conductivity, in such a way that model and test results match. The thermal model reproduces the thermal tests to an accuracy of 4.2 °C ± 3.2 °C in a temperature range of 200 °C after using only 600 iteration steps of the correlation algorithm. The use of this method brings major benefits to the accuracy of the results as well as to the computational time required for the correlation. - Highlights: ► We present model correlations of the BELA receiver baffle to thermal balance tests. ► Adaptive particle swarm optimization has been adapted for the correlation. ► The method improves the accuracy of the correlation and the computational time.

  10. Study of the response of Zircaloy- 4 cladding to thermal shock during water quenching after double sided steam oxidation at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sawarn, Tapan K., E-mail: sawarn@barc.gov.in; Banerjee, Suparna; Kumar, Sunil

    2016-05-15

    This study investigates the failure of embrittled Zircaloy-4 cladding in a simulated loss of coolant accident condition and correlates it with the evolved stratified microstructure. Isothermal steam oxidation of Zircaloy-4 cladding at high temperatures (900–1200 °C) with soaking periods in the range 60–900 s followed by water quenching was carried out. The combined oxide + oxygen stabilized α-Zr layer thickness and the fraction of the load bearing phase (recrystallised α-Zr grains + prior β-Zr or only prior β-Zr) of clad tube specimens were correlated with the %ECR calculated using Baker-Just equation. Average oxygen concentration of the load bearing phase corresponding to different oxidation conditions was calculated from the average microhardness using an empirical correlation. The results of these experiments are presented in this paper. Thermal shock sustainability of the clad was correlated with the %ECR, combined oxide+α-Zr(O) layer thickness, fraction of the load bearing phase and its average oxygen concentration. - Highlights: • Response of the embrittled Zircaloy-4 clad towards thermal shock, simulated under LOCA condition was investigated. • Thermal shock sustainability of the clad was correlated with its evolved stratified microstructure. • Cladding fails at %ECR value ≥ 29. • To resist the thermal shock, clad should have load bearing phase fraction > 0.44 and average oxygen concentration < 0.69 wt%.

  11. Experiment Study on Elastic Indicator of Thermal Shock Ceramic Materials——Implementation of Students’ Innovative Research Project of Shandong University of Science and Technology

    Directory of Open Access Journals (Sweden)

    Wang Yanxia

    2017-01-01

    Full Text Available In order to improve the quality of undergraduate education and combine theory and practice, Shandong University of science and technology organized innovative research activities project for undergraduates. Combined with the characteristics of engineering mechanics course, teachers of engineering mechanics teaching and research section guided students to take an active part in scientific research and innovation practice teaching, which has obtained a good teaching effect. This paper introduces the concrete implement process of the college students’ innovative scientific research project “Experiment Study on Elastic Indicator of Thermal Shock Ceramic Materials”, which measures elastic indicator of ceramics using the ultrasonic method. This paper studies elastic indicator change rule of the mullite ceramic samples under different factors such as temperature difference, thermal shock times and so on. Studies have shown that in the condition of air-cooling, with the increase of thermal shock temperature difference and thermal shock times, the elastic modulus value, shear modulus and Poisson’s ratio are in a falling trend. The project implementation have proved that implement undergraduate innovation research projects could effectively arouse students’ learning enthusiasm, cultivate students’ scientific research innovation and analytical abilities to solve practical scientific research problems.

  12. A fractographic study of cracks produced by thermal shocks in 20MnMoNi55 and comparable weld material in water environment

    International Nuclear Information System (INIS)

    Toerroenen, K.; Rintamaa, R.; Kemppainen, M.

    1983-04-01

    This report gives the results of a fractographic study of cracks produced by thermal shocks in 20MnMoNi55 and comparable weld material in water environment. The basic crack growth mechanism is shown to be by mechanical fatigue, but after some crack growth indications of environmentally assisted cyclic crack growth is seen. (author)

  13. Thermal Analysis of a SHIELD Electromigration Test Structure

    Energy Technology Data Exchange (ETDEWEB)

    Benson, David A.; Bowman, Duane J.; Mitchell, Robert T.

    1999-05-01

    The steady state and transient thermal behavior of an electromigration test structure was analyzed. The test structure was a Sandia SHIELD (Self-stressing HIgh fregquency rELiability Device) electromigration test device manufactured by an outside vendor. This device has a high frequency oscillator circuit, a buffer circuit to isolate and drive the metal line to the tested (DUT), the DUT to be electromigrated itself, a metal resistance thermometry monitor, and a heater elment to temperature accelerate the electromigration effect.

  14. A Thermal Test System for Helmet Cooling Studies

    Directory of Open Access Journals (Sweden)

    Shaun Fitzgerald

    2018-02-01

    Full Text Available One of the primary causes of discomfort to both irregular and elite cyclists is heat entrapment by a helmet resulting in overheating and excessive sweating of the head. To accurately assess the cooling effectiveness of bicycle helmets, a heated plastic thermal headform has been developed. The construction consists of a 3D-printed headform of low thermal conductivity with an internal layer of high thermal mass that is heated to a constant uniform temperature by an electrical heating element. Testing is conducted in a wind tunnel where the heater power remains constant and the resulting surface temperature distribution is directly measured by 36 K-type thermocouples embedded within the surface of the head in conjunction with a thermal imaging camera. Using this new test system, four bicycle helmets were studied in order to measure their cooling abilities and to identify ‘hot spots’ where cooling performance is poor.

  15. Geographic variation in thermal tolerance and strategies of heat shock protein expression in the land snail Theba pisana in relation to genetic structure.

    Science.gov (United States)

    Mizrahi, Tal; Goldenberg, Shoshana; Heller, Joseph; Arad, Zeev

    2016-03-01

    Land snails are exposed to conditions of high ambient temperature and low humidity, and their survival depends on a suite of morphological, behavioral, physiological, and molecular adaptations to the specific microhabitat. We tested in six populations of the land snail Theba pisana whether adaptations to different habitats affect their ability to cope with thermal stress and their strategies of heat shock protein (HSP) expression. Levels of Hsp70 and Hsp90 in the foot tissue were measured in field-collected snails and after acclimation to laboratory conditions. Snails were also exposed to various temperatures (32 up to 54 °C) for 2 h and HSP messenger RNA (mRNA) levels were measured in the foot tissue and survival was determined. To test whether the physiological and molecular data are related to genetic parameters, we analyzed T. pisana populations using partial sequences of nuclear and mitochondrial DNA ribosomal RNA genes. We show that populations collected from warmer habitats were more thermotolerant and had higher constitutive levels of Hsp70 isoforms in the foot tissue. Quantitative real-time polymerase chain reaction (PCR) analysis indicated that hsp70 and hsp90 mRNA levels increased significantly in response to thermal stress, although the increase in hsp70 mRNA was larger compared to hsp90 and its induction continued up to higher temperatures. Generally, warm-adapted populations had higher temperatures of maximal induction of hsp70 mRNA synthesis and higher upper thermal limits to HSP mRNA synthesis. Our study suggests that Hsp70 in the foot tissue of T. pisana snails may have important roles in determining stress resistance, while Hsp90 is more likely implicated in signal transduction processes that are activated by stress. In the phylogenetic analysis, T. pisana haplotypes were principally divided into two major clades largely corresponding to the physiological ability to withstand stress, thus pointing to genetically fixed tolerance.

  16. COMPARISON OF RESULTS OF THERMAL TESTS OF BALCONY DOORS

    Directory of Open Access Journals (Sweden)

    Golubev Stanislav Sergeevich

    2012-10-01

    Full Text Available Results of thermal tests of balcony doors are presented in the article. In the course of the research project, two types of doors were tested. The first type represents a PVC frame door (width 82 mm; it has a triple glazing (4K-16Ar-4-16Ar-K4; its blank part represents a polystyrene sandwich panel (width 40 mm. The second type represents a PVC frame door (width 82 mm, that has a triple glazing (4K-16Ar-4-16Ar-K4 and composite PVC panels. The testing procedure and processing results are described in the article. The test has demonstrated that the thermal resistance value of the balcony door of the first type exceeds the thermal resistance value of the balcony door of the second type.

  17. Dynamic loads on human and animal surrogates at different test locations in compressed-gas-driven shock tubes

    Science.gov (United States)

    Alay, E.; Skotak, M.; Misistia, A.; Chandra, N.

    2018-01-01

    Dynamic loads on specimens in live-fire conditions as well as at different locations within and outside compressed-gas-driven shock tubes are determined by both static and total blast overpressure-time pressure pulses. The biomechanical loading on the specimen is determined by surface pressures that combine the effects of static, dynamic, and reflected pressures and specimen geometry. Surface pressure is both space and time dependent; it varies as a function of size, shape, and external contour of the specimens. In this work, we used two sets of specimens: (1) anthropometric dummy head and (2) a surrogate rodent headform instrumented with pressure sensors and subjected them to blast waves in the interior and at the exit of the shock tube. We demonstrate in this work that while inside the shock tube the biomechanical loading as determined by various pressure measures closely aligns with live-fire data and shock wave theory, significant deviations are found when tests are performed outside.

  18. Data from thermal testing of the Open Source Cryostage

    DEFF Research Database (Denmark)

    Buch, Johannes Lørup; Ramløv, Hans

    2016-01-01

    The data presented here is related to the research article "An open source cryostage and software analysis method for detection of antifreeze activity" (Buch and Ramløv, 2016) [1]. The design of the Open Source Cryostage (OSC) is tested in terms of thermal limits, thermal efficiency and electrical...... efficiency. This article furthermore includes an overview of the electrical circuitry and a flowchart of the software program controlling the temperature of the OSC. The thermal efficiency data is presented here as degrees per volt and maximum cooling capacity....

  19. Documentation of probabilistic fracture mechanics codes used for reactor pressure vessels subjected to pressurized thermal shock loading: Parts 1 and 2. Final report

    International Nuclear Information System (INIS)

    Balkey, K.; Witt, F.J.; Bishop, B.A.

    1995-06-01

    Significant attention has been focused on the issue of reactor vessel pressurized thermal shock (PTS) for many years. Pressurized thermal shock transient events are characterized by a rapid cooldown at potentially high pressure levels that could lead to a reactor vessel integrity concern for some pressurized water reactors. As a result of regulatory and industry efforts in the early 1980's, a probabilistic risk assessment methodology has been established to address this concern. Probabilistic fracture mechanics analyses are performed as part of this methodology to determine conditional probability of significant flaw extension for given pressurized thermal shock events. While recent industry efforts are underway to benchmark probabilistic fracture mechanics computer codes that are currently used by the nuclear industry, Part I of this report describes the comparison of two independent computer codes used at the time of the development of the original U.S. Nuclear Regulatory Commission (NRC) pressurized thermal shock rule. The work that was originally performed in 1982 and 1983 to compare the U.S. NRC - VISA and Westinghouse (W) - PFM computer codes has been documented and is provided in Part I of this report. Part II of this report describes the results of more recent industry efforts to benchmark PFM computer codes used by the nuclear industry. This study was conducted as part of the USNRC-EPRI Coordinated Research Program for reviewing the technical basis for pressurized thermal shock (PTS) analyses of the reactor pressure vessel. The work focused on the probabilistic fracture mechanics (PFM) analysis codes and methods used to perform the PTS calculations. An in-depth review of the methodologies was performed to verify the accuracy and adequacy of the various different codes. The review was structured around a series of benchmark sample problems to provide a specific context for discussion and examination of the fracture mechanics methodology

  20. Thermal stresses in the space shuttle orbiter: Analysis versus test

    International Nuclear Information System (INIS)

    Grooms, H.R.; Gibson, W.F. Jr.; Benson, P.L.

    1984-01-01

    Significant temperature differences occur between the internal structure and the outer skin of the Space Shuttle Orbiter as it returns from space. These temperature differences cause important thermal stresses. A finite element model containing thousands of degrees of freedom is used to predict these stresses. A ground test was performed to verify the prediction method. The analysis and test results compare favorably. (orig.)

  1. Research on the Random Shock Vibration Test Based on the Filter-X LMS Adaptive Inverse Control Algorithm

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2016-01-01

    Full Text Available The related theory and algorithm of adaptive inverse control were presented through the research which pointed out the adaptive inverse control strategy could effectively eliminate the noise influence on the system control. Proposed using a frequency domain filter-X LMS adaptive inverse control algorithm, and the control algorithm was applied to the two-exciter hydraulic vibration test system of random shock vibration control process and summarized the process of the adaptive inverse control strategies in the realization of the random shock vibration test. The self-closed-loop and field test show that using the frequency-domain filter-X LMS adaptive inverse control algorithm can realize high precision control of random shock vibration test.

  2. CRYogenic Orbital TEstbed Ground Test Article Thermal Analysis

    Science.gov (United States)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to CRYOTE ground test data. The CRYOTE ground test artide was jointly developed by Innovative Engineering Solutions, United Launch Alliance and NASA KSC. The test article was constructed out of a titanium alloy tank, Sapphire 77 composite skin (similar to G10), an external secondary payload adapter ring, thermal vent system, multi layer insulation and various data acquisition instrumentation. In efforts to understand heat loads throughout this system, the GTA (filled with liquid nitrogen for safety purposes) was subjected to a series of tests in a vacuum chamber at Marshall Space Flight Center. By anchoring analytical models against test data, higher fidelity thermal environment predictions can be made for future flight articles which would eventually demonstrate critical cryogenic fluid management technologies such as system chilldown, transfer, pressure control and long term storage. Significant factors that influenced heat loads included radiative environments, multi-layer insulation performance, tank fill levels and pressures and even contact conductance coefficients. This report demonstrates how analytical thermal/fluid networks were established and includes supporting rationale for specific thermal responses.

  3. Maximum thermal loading test of BWR fuel assembly

    International Nuclear Information System (INIS)

    Nakajima, Yoshitaka; Yoshimura, Kunihiro; Nakamura, Satoshi; Ishizuka, Takao.

    1987-01-01

    Various proving tests on the reliability of nuclear power plants have been conducted at the Nuclear Power Engineering Test Center and at the Japan Power Plant Engineering and Inspection Corporation. The tests were initiated at the request of the Ministry of International Trade and Industry (MITI). Toshiba undertook one of the proving tests on the reliability of nuclear fuel assembly; the maximum thermal loading test of BWR fuel assembly from the Nuclear Power Engineering Test Center. These tests are part of the proving tests mentioned above, and their purpose is to confirm the reliability of the thermal hydraulic engineering techniques. Toshiba has been engaged for the past nine years in the design, fabrication and testing of the equipment. For the project, a test model fuel assembly was used to measure the critical power of the BWR fuel assembly and the void and fluidity of the coolant. From the test results, it has been confirmed that the heat is transferred safely from the fuel assembly to the coolant in the BWR nuclear power plant. In addition, the propriety and reliability of the thermal hydraulic engineering techniques for the fuel assembly have been proved. (author)

  4. Interfacial Characteristics of TiN Coatings on SUS304 and Silicon Wafer Substrates with Pulsed Laser Thermal Shock

    International Nuclear Information System (INIS)

    Seo, Nokun; Jeon, Seol; Choi, Youngkue; Shin, Hyun-Gyoo; Lee, Heesoo; Jeon, Min-Seok

    2014-01-01

    TiN coatings prepared on different substrates that had different coefficients of thermal expansion were subjected to pulsed laser thermal shock and observed by using FIB milling to compare the deterioration behaviors. TiN coating on SUS304, which had a larger CTE (⁓17.3 × 10 - 6 /℃) than the coating was degraded with pores and cracks on the surface and showed significant spalling of the coating layer over a certain laser pulses. TiN coating on silicon wafer with a smaller CTE value, ⁓4.2 × 10‒6 /℃, than the coating exhibited less degradation of the coating layer at the same ablation condition. Cracks propagated at the interface were observed in the coating on the silicon wafer, which induced a compressive stress to the coating. The coating on the SUS304 showed less interface cracks while the tensile stress was applied to the coating. Delamination of the coating layer related to the intercolumnar cracks at the interface was observed in both coatings through bright-field TEM analysis.

  5. Pressurized thermal shock. CNA-I behavior when a hot leg breaks of 50 cm2 is produced

    International Nuclear Information System (INIS)

    Rosso, Ricardo D.; Ventura, Mirta A.

    2002-01-01

    Pressurized thermal shock (PTS) phenomena in the CNA-I pressurize heavy water reactor is analyzed in this paper. The initiating event is a hypothetical 50 cm 2 break of the line connecting the pressurizer and the primary system. The calculation procedure for obtaining the local thermal-hydraulic parameters in the reactor pressure vessel downcomer is described firstly. Results obtained lead to conclusions in different subjects. The first conclusion is that a simple tool of easy application is available to analyze PTS phenomena in cases of breaks in the primary system in cold and hot legs. This methodology is fully independent of the methodology utilized by the Utility. Another important conclusion comes from the analysis of the temperature evolution of the fluid below the cold leg level in the RPV downcomer, as a function of the T HPI temperature of the TJ system injected water from. It is also concluded that the results obtained with the methodology adopted agree with the ones obtained with the methodologies validated against experiments in the UPTF facility. It is possible to observe that when T HPI increase, the conditions suitable for PTS occurrence in a LOCA accident tend to diminish. The maximum value to the T HPI may be fixed from the maximum temperature allowed to preserve the structural integrity of the fuel cladding. (author)

  6. TRAC-PF1 analyses of potential pressurized-thermal-shock transients at a Combustion-Engineering PWR

    International Nuclear Information System (INIS)

    Koenig, J.E.; Spriggs, G.D.; Smith, R.C.

    1984-01-01

    Los Alamos is participating in a program to assess the risk of pressurized thermal shock (PTS) to a reactor vessel. Our role is to provide best-estimate thermal-hydraulic analyses of 12 postulated overcooling transients using TRAC-PF1. These transients are hypothetical and include multiple operator/equipment failures. Calvert Cliffs/Unit-1, a Combustion-Engineering plant, is the pressurized water reactor modeled for this study. The utility and the vendor supplied information for the comprehensive TRAC-PF1 model. Secondary and primary breaks from both hot-zero-power and full-power conditions were simulated for 7200 s (2 h). Low bulk temperatures and loop-flow stagnation while the system was at a high pressure were of particular interest for PTS analysis. Three transients produced primary temperatures below 405 K (270 0 F - the NRC screening criterion) with system repressurization. Six transients indicated flow stagnation would occur in one loop but not both. One transient showed flow stagnation might occur in both loops. Oak Ridge National Laboratory will do fracture-mechanics analysis using these TRAC-PF1 results and make the final determination of the risk of PTS

  7. Evaluating piezo-electric transducer response to thermal shock from in-cilinder pressure data

    NARCIS (Netherlands)

    Baert, R.S.G.; Rosseel, E.; Sierens, R.

    1999-01-01

    One of the major effects limiting the accuracy of piezoelectric transducers for performing in-cylinder pressure measurements is their sensitivity to the cyclic thermal loading effects of the intermittent combustion process. This paper compares five different methods for evaluating the effect of this

  8. Characterization of heat shock cognate protein 70 gene and its differential expression in response to thermal stress between two wing morphs of Nilaparvata lugens (Stål).

    Science.gov (United States)

    Lu, Kai; Chen, Xia; Liu, Wenting; Zhou, Qiang

    2016-09-01

    Previous studies have demonstrated differences in thermotolerance between two wing morphs of Nilaparvata lugens, the most serious pest of rice across the Asia. To reveal the molecular regulatory mechanisms underlying the differential thermal resistance abilities between two wing morphs, a full-length of transcript encoding heat shock cognate protein 70 (Hsc70) was cloned, and its expression patterns across temperature gradients were analyzed. The results showed that the expression levels of NlHsc70 in macropters increased dramatically after heat shock from 32 to 38°C, while NlHsc70 transcripts in brachypters remained constant under different temperature stress conditions. In addition, NlHsc70 expression in the macropters was significantly higher than that in brachypters at 1 and 2h recovery from 40°C heat shock. There was no significant difference in NlHsc70 mRNA expression between brachypters and macropters under cold shock conditions. Therefore, NlHsc70 was indeed a constitutively expressed member of the Hsp70 family in brachypters of N. lugens, while it was heat-inducible in macropters. Furthermore, the survival rates of both morphs injected with NlHsc70 dsRNA were significantly decreased following heat shock at 40°C or cold shock at 0°C for 1h. These results suggested that the up-regulation of NlHsc70 is possibly related to the thermal resistance, and the more effective inducement expression of NlHsc70 in macropters promotes a greater thermal tolerance under temperature stress conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Thermal Environmental Testing of NSTAR Engineering Model Ion Thrusters

    Science.gov (United States)

    Rawlin, Vincent K.; Patterson, Michael J.; Becker, Raymond A.

    1999-01-01

    NASA's New Millenium program will fly a xenon ion propulsion system on the Deep Space 1 Mission. Tests were conducted under NASA's Solar Electric Propulsion Technology Applications Readiness (NSTAR) Program with 3 different engineering model ion thrusters to determine thruster thermal characteristics over the NSTAR operating range in a variety of thermal environments. A liquid nitrogen-cooled shroud was used to cold-soak the thruster to -120 C. Initial tests were performed prior to a mature spacecraft design. Those results and the final, severe, requirements mandated by the spacecraft led to several changes to the basic thermal design. These changes were incorporated into a final design and tested over a wide range of environmental conditions.

  10. Thermal results of the Japanese LCT coil's domestic test

    International Nuclear Information System (INIS)

    Tada, Eisuke; Hiyama, Tadao; Kato, Takashi; Takahashi, Osamu; Shimamoto, Susumu

    1984-01-01

    This paper describes thermal results obtained in the domestic test of the Japanese LCT coil which was constructed at the Japan Atomic Energy Research Institute (JAERI) in order to develop large superconducting coils for fusion in international collaboration proposed by the IEA. The domestic test was carried out from May 13 to June 17 in 1982 by using the test facility named as SETF (Superconducting Engineering Test Facility) which was composed of a 350-l/h helium cryogenic system, a vacuum system, a 30 KA-DC power supply and protection system, and a PDP-11/70 computer system. The cool-down characteristics, heat load, fast discharge characteristics, stability, and warm-up characteristics of the LCT coil were successfully measured in the test. The details of thermal test results acquired in the cool-down, heat load measurement, fast discharge, and warm-up, and the comparison between measurements and calculations are described in this paper. (author)

  11. A study on thermal ratcheting structure test of 316L test cylinder

    International Nuclear Information System (INIS)

    Lee, H. Y.; Kim, J. B.; Koo, G. H.

    2001-01-01

    In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature liquid metal reactor was simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The inelastic deformation of the reactor baffle cylinder can occur due to the moving temperature distribution along the axial direction as the hot free surface moves up and down under the cyclic heat-up and cool-down of reactor operations. The ratchet deformations were measured with the laser displacement sensor and LVDTs after cooling the structural specimen which experiences thermal load up to 550 .deg. C and the temperature differences of about 500 .deg. C. During structural thermal ratchet test, the temperature distribution of the test cylinder along the axial direction was measured from 28 channels of thermocouples and the temperatures were used for the ratchet analysis. The thermal ratchet deformation analysis was performed with the NONSTA code whose constitutive model is nonlinear combined kinematic and isotropic hardening model and the test results were compared with those of the analysis. Thermal ratchet test was carried out with respect to 9 cycles of thermal loading and the maximum residual displacements were measured to be 1.8mm. It was shown that thermal ratchet load can cause a progressive deformation to the reactor structure. The analysis results with the combined hardening model were in reasonable agreement with those of the tests

  12. Thermal Vacuum Test Correlation of A Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytics Model

    Science.gov (United States)

    McKim, Stephen A.

    2016-01-01

    This thesis describes the development and test data validation of the thermal model that is the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented to validate the model are presented. The thermal model was correlated to within plus or minus 3 degrees Centigrade of the thermal vacuum test data, and was found to be relatively insensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed, however, to refine the thermal model to further improve temperature predictions in the upper hemisphere of the propellant tank. Temperatures predictions in this portion were found to be 2-2.5 degrees Centigrade lower than the test data. A road map to apply the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

  13. Thermal testing transport packages for radioactive materials: Reality vs regulation

    International Nuclear Information System (INIS)

    Hovingh, J.; Carlson, R.W.

    1994-03-01

    The principle objective of this paper is to provide information that will help describe the physical thermal tests performed to demonstrate compliance with the hypothetical accident conditions specified in 10 CFR 71.73. Physical testing should be applied to packages that cannot be modeled by analysis to adequately predict their response to hypothetical accident conditions. These tests should be used when chemical decomposition or material changes occur during an accident that would be difficult to analytically predict or model

  14. Effect of LaB6 on the thermal shock property of MoSi2-SiC coating for carbon/carbon composites

    International Nuclear Information System (INIS)

    Li Ting; Li Hejun; Shi Xiaohong

    2013-01-01

    Highlights: ► LaB 6 -MoSi 2 -SiC and MoSi 2 -SiC multi-composition coatings were coated on C/C composites by pack cementation. ► The microstructure and thermal shock resistance of both coatings were investigated. ► The addition of LaB 6 can increase the compactness, flexural strength and fracture toughness of the MoSi 2 -SiC coating simultaneously. ► Both coatings bond well with the substrates before and after thermal cycling oxidation between 1773 K and room temperature. ► The LaB 6 -MoSi 2 -SiC coated C/C shows better thermal shock resistance than the MoSi 2 -SiC coated C/C. - Abstract: LaB 6 -MoSi 2 -SiC and MoSi 2 -SiC coatings were prepared on the surface of carbon/carbon composites by pack cementation method. The crystal structures of the coatings were measured by X-ray diffraction. The morphologies and element distributions were also analyzed by scanning electron microscopy and energy dispersive spectroscopy, respectively. The effect of LaB 6 on the microstructure and thermal shock resistance of MoSi 2 -SiC coating was investigated. The results indicated that the LaB 6 -MoSi 2 -SiC coating possessed a denser structure and superior thermal shock resistance. After 25 times of thermal cycling oxidation between 1773 K and room temperature, the weight losses of the LaB 6 -MoSi 2 -SiC and MoSi 2 -SiC coated samples were 0.627% and 2.019%, respectively.

  15. A study of thermal stratification in the cold legs during the subcooled blowdown phase of a loss of coolant accident in the OSU APEX thermal hydraulic testing facility

    International Nuclear Information System (INIS)

    Wachs, D. M.

    1998-01-01

    Thermal stratification, which has been linked to the occurrence of pressurized thermal shock (PTS), is observed to occur during the early stages of simulated loss of coolant accidents (LOCAS) in the Oregon State University Advanced Plant Experiment (OSU APEX) Thermal Hydraulic Test Facility. The OSU APEX Test Facility is a scaled model of the Westinghouse AP600 nuclear power plant. Analysis of the OSU APEX facility data has allowed the determination of an onset criteria for thermal stratification and has provided support for the postulated mechanisms leading to thermal stratification. CFX 4.1, a computational fluid dynamics code, was used to generate a model of the cold legs and the downcomer that described the phenomena occurring within them. Some mixing phenomena were predicted that lead to non-uniformity between the two cold legs attached to the steam generator on the side of the facility containing the Passive Residual Heat Removal (PRHR) injection system. The stratification was found to be two phase and unlikely to be a factor in PTS

  16. Handling effluent from nuclear thermal propulsion system ground tests

    International Nuclear Information System (INIS)

    Shipers, L.R.; Allen, G.C.

    1992-01-01

    A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the different methods to handle effluent from nuclear thermal propulsion system ground tests

  17. Effluent treatment options for nuclear thermal propulsion system ground tests

    International Nuclear Information System (INIS)

    Shipers, L.R.; Brockmann, J.E.

    1992-01-01

    A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the strengths and weaknesses of different methods to handle effluent from nuclear thermal propulsion system ground tests

  18. Thermal performance test for steam turbine of nuclear power plants

    International Nuclear Information System (INIS)

    Bu Yubing; Xu Zongfu; Wang Shiyong

    2014-01-01

    Through study of steam turbine thermal performance test of CPR1000 nuclear power plant, we solve the enthalpy calculation problems of the steam turbine in wet steam zone using heat balance method which can help to figure out the real overall heat balance diagram for the first time, and we develop a useful software for thermal heat balance calculation. Ling'ao phase II as an example, this paper includes test instrument layout, system isolation, risk control, data acquisition, wetness measurement, heat balance calculation, etc. (authors)

  19. Experimental analysis on physical and mechanical properties of thermal shock damage of granite

    Directory of Open Access Journals (Sweden)

    He Xiao

    2017-01-01

    Full Text Available The purpose of this study was to explore the changes of mechanical and physical properties of granite under different thermal loading effects. Uniaxial compression experiments studying the rules of the influence of temperature load on mechanical properties of granite were carried out. After high-temperature heating at above 600 °C, granite tended to have stronger ductility and plasticity as well as declined peak stress and compressive strength. Thermogravimetry - differential scanning calorimetry (TG-DSC analysis results showed that, thermal load at different temperatures induced reactions such as water loss, oxidation and crystallization in the microstructure of granite, which led to physical changes of granite. Hence it is concluded that, heating can significantly weaken the mechanical performance of granite, which provides an important support for the optimization of heating assisted processing of granite. It also reveals that, heating assisted cutting technique can effectively lower energy consumption and improve processing efficiency.

  20. Effect of thermal shock on developmental stages of estuarine fish. Final report

    International Nuclear Information System (INIS)

    Dean, J.M.

    1978-12-01

    Physiological data and ecological data show that the few estuarine spawners have a higher thermal tolerance in the embryonic and larval stages than do the freshwater, coastal, or oceanic spawning species. However, since all three groups (freshwater, estuarine, and oceanic spawners) occupy the estuary and coastal waters at different times of the year, knowledge of their physiology and ecology at different developmental or life cycle stages is critical for estuarine management decisions

  1. Thermal hydraulic-Mechanic Integrated Simulation for Advanced Cladding Thermal Shock Fracture Analysis during Reflood Phase in LBLOCA

    Energy Technology Data Exchange (ETDEWEB)

    Son, Seong Min; Lee, You Ho; Cho, Jae Wan; Lee, Jeong Ik [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This study suggested thermal hydraulic-mechanical integrated stress based methodology for analyzing the behavior of ATF type claddings by SiC-Duplex cladding LBLOCA simulation. Also, this paper showed that this methodology could predict real experimental result well. That concept for enhanced safety of LWR called Advanced Accident-Tolerance Fuel Cladding (ATF cladding, ATF) is researched actively. However, current nuclear fuel cladding design criteria for zircaloy cannot be apply to ATF directly because those criteria are mainly based on limiting their oxidation. So, the new methodology for ATF design criteria is necessary. In this study, stress based analysis methodology for ATF cladding design criteria is suggested. By simulating LBLOCA scenario of SiC cladding which is the one of the most promising candidate of ATF. Also we'll confirm our result briefly through comparing some facts from other experiments. This result is validating now. Some of results show good performance with 1-D failure analysis code for SiC fuel cladding that already developed and validated by Lee et al,. It will present in meeting. Furthermore, this simulation presented the possibility of understanding the behavior of cladding deeper. If designer can predict the dangerous region and the time precisely, it may be helpful for designing nuclear fuel cladding geometry and set safety criteria.

  2. Endogenous Versus Exogenous Shocks in Complex Networks: An Empirical Test Using Book Sale Rankings

    Science.gov (United States)

    Sornette, D.; Deschâtres, F.; Gilbert, T.; Ageon, Y.

    2004-11-01

    We study the precursory and recovery signatures accompanying shocks in complex networks, that we test on a unique database of the Amazon.com ranking of book sales. We find clear distinguishing signatures classifying two types of sales peaks. Exogenous peaks occur abruptly and are followed by a power law relaxation, while endogenous peaks occur after a progressively accelerating power law growth followed by an approximately symmetrical power law relaxation which is slower than for exogenous peaks. These results are rationalized quantitatively by a simple model of epidemic propagation of interactions with long memory within a network of acquaintances. The observed relaxation of sales implies that the sales dynamics is dominated by cascades rather than by the direct effects of news or advertisements, indicating that the social network is close to critical.

  3. Separate effects tests to determine the effective thermal conductivity in the PBMR HTTU test facility

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P.G., E-mail: pgr@mtechindustrial.com [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Toit, C.G. du; Antwerpen, W. van [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Antwerpen, H.J. van [M-Tech Industrial (Pty) Ltd., PO Box 19855, Noordbrug 2522 (South Africa)

    2014-05-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTU non-nuclear test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effective thermal conductivity through the pebble bed under near-vacuum conditions and temperatures up to 1200 °C. It also presents the measured temperature distributions and the methodology applied in the data analysis to derive the resultant values of effective thermal conductivity and its associated uncertainty.

  4. Separate effects tests to determine the effective thermal conductivity in the PBMR HTTU test facility

    International Nuclear Information System (INIS)

    Rousseau, P.G.; Toit, C.G. du; Antwerpen, W. van; Antwerpen, H.J. van

    2014-01-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTU non-nuclear test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effective thermal conductivity through the pebble bed under near-vacuum conditions and temperatures up to 1200 °C. It also presents the measured temperature distributions and the methodology applied in the data analysis to derive the resultant values of effective thermal conductivity and its associated uncertainty

  5. Approximating a free-field blast environment in the test section of an explosively driven conical shock tube

    Science.gov (United States)

    Stewart, J. B.

    2018-02-01

    This paper presents experimental data on incident overpressures and the corresponding impulses obtained in the test section of an explosively driven 10° (full angle) conical shock tube. Due to the shock tube's steel walls approximating the boundary conditions seen by a spherical sector cut out of a detonating sphere of energetic material, a 5.3-g pentolite shock tube driver charge produces peak overpressures corresponding to a free-field detonation from an 816-g sphere of pentolite. The four test section geometries investigated in this paper (open air, cylindrical, 10° inscribed square frustum, and 10° circumscribed square frustum) provide a variety of different time histories for the incident overpressures and impulses, with a circumscribed square frustum yielding the best approximation of the estimated blast environment that would have been produced by a free-field detonation.

  6. Thermal fatigue behavior of valves

    International Nuclear Information System (INIS)

    Moinereau, D.; Scliffet, L.; Capion, J.C.; Genette, P.

    1991-01-01

    This paper reports that valves of pressurized water reactors are exposed to thermal shocks during transient operations. The numerous thermal shock tests performed on valves on the EDF test facilities have shown the sensibility of fillets and geometrical discontinuities to thermal fatigue: cracks can appear in those areas and grow through the valve body. Valves systems designated as level 1 must be designed to withstand fatigue up to the second isolation valve: the relevant rule is specified in the paragraph B 3500 of the French RCCM code. It is a simplified method which doesn't require finite element calculations. Many valve systems have been designed according to this rule and have been operated without accident. However, in one case, important cracks were found in the fillet of a check-valve after numerous thermal shocks. Calculation of the valve's behavior according to the RCCM code to estimate the fatigue damage resulting from thermal shocks led to a low damage factor, which doesn't agree with the experimental results. This was confirmed by new testings and showed the inadequacy of B 3500 rule for thermal transients. On this base a new rule is proposed to estimate fatigue damage resulting from thermal shocks. An experimental program has been realized to validate this rule. Axisymetrical analytical mock-ups with different geometries and one check-valve in austenitic stainless steel 316 L have been submitted to hot thermal shocks of 210 degrees C magnitude

  7. Shock wave effects in copper: Design of an experimental device for post recovery mechanical testing

    International Nuclear Information System (INIS)

    Buy, Francois; Llorca, Fabrice

    2002-01-01

    The mechanical behavior of metals may prove high changes with strain rate and pressure loading history. In order to investigate the effect of a shock on the ulterior mechanical behavior of high purity copper, we set up an experimental device inspired from G. T. Gray III's works. This device, based on the trapping of shock waves after a plane plate impact is validated by numerical simulations. The aim of these simulations is the evaluation of the heterogeneity of plastic deformation. Shock pressures up to 10 GPa have been investigated. The plastic strain levels subsequent to the shock are between 0.08 and 0.15 in the sample

  8. Engineered Barrier System Thermal-Hydraulic-Chemical Column Test Report

    International Nuclear Information System (INIS)

    W.E. Lowry

    2001-01-01

    The Engineered Barrier System (EBS) Thermal-Hydraulic-Chemical (THC) Column Tests provide data needed for model validation. The EBS Degradation, Flow, and Transport Process Modeling Report (PMR) will be based on supporting models for in-drift THC coupled processes, and the in-drift physical and chemical environment. These models describe the complex chemical interaction of EBS materials, including granular materials, with the thermal and hydrologic conditions that will be present in the repository emplacement drifts. Of particular interest are the coupled processes that result in mineral and salt dissolution/precipitation in the EBS environment. Test data are needed for thermal, hydrologic, and geochemical model validation and to support selection of introduced materials (CRWMS M and O 1999c). These column tests evaluated granular crushed tuff as potential invert ballast or backfill material, under accelerated thermal and hydrologic environments. The objectives of the THC column testing are to: (1) Characterize THC coupled processes that could affect performance of EBS components, particularly the magnitude of permeability reduction (increases or decreases), the nature of minerals produced, and chemical fractionation (i.e., concentrative separation of salts and minerals due to boiling-point elevation). (2) Generate data for validating THC predictive models that will support the EBS Degradation, Flow, and Transport PMR, Rev. 01

  9. BWR 9 X 9 Fuel Assembly Thermal-Hydraulic Tests (2): Hydraulic Vibration Test

    International Nuclear Information System (INIS)

    Yoshiaki Tsukuda; Katsuichiro Kamimura; Toshiitsu Hattori; Akira Tanabe; Noboru Saito; Masahiko Warashina; Yuji Nishino

    2002-01-01

    Nuclear Power Engineering Corporation (NUPEC) conducted thermal-hydraulic projects for verification of thermal-hydraulic design reliability for BWR high-burnup 8 x 8 and 9 x 9 fuel assemblies, entrusted by the Ministry of Economy, Trade and Industry (METI). As a part of the NUPEC thermal-hydraulic projects, hydraulic vibration tests using full-scale test assemblies simulating 9 x 9 fuel assemblies were carried out to evaluate BWR fuel integrity. The test data were applied to development of a new correlation for the estimation of fuel rod vibration amplitude. (authors)

  10. Impact Testing of Orbiter Thermal Protection System Materials

    Science.gov (United States)

    Kerr, Justin

    2006-01-01

    This viewgraph presentation reviews the impact testing of the materials used in designing the shuttle orbiter thermal protection system (TPS). Pursuant to the Columbia Accident Investigation Board recommendations a testing program of the TPS system was instituted. This involved using various types of impactors in different sizes shot from various sizes and strengths guns to impact the TPS tiles and the Leading Edge Structural Subsystem (LESS). The observed damage is shown, and the resultant lessons learned are reviewed.

  11. Pressurized thermal shock in nuclear power plants: Good practices for assessment. Deterministic evaluation for the integrity of reactor pressure vessel

    International Nuclear Information System (INIS)

    2010-02-01

    Starting in the early 1970s, a series of coordinated research projects (CRPs) was sponsored by the IAEA focusing on the effects of neutron radiation on reactor pressure vessel (RPV) steels and RPV integrity. In conjunction with these CRPs, many consultants meetings, specialists meetings, and international conferences, dating back to the mid-1960s, were held. Individual studies on the basic phenomena of radiation hardening and embrittlement were also performed to better understand increases in tensile strength and shifts to higher temperatures for the integrity of the RPV. The overall objective of this CRP was to perform benchmark deterministic calculations of a typical pressurized thermal shock (PTS) regime, with the aim of comparing the effects of individual parameters on the final RPV integrity assessment, and then to recommend the best practices for their implementation in PTS procedures. At present, several different procedures and approaches are used for RPV integrity assessment for both WWER 440-230 reactors and pressurized water reactors (PWRs). These differences in procedures and approaches are based, in principle, on the different codes and rules used for design and manufacturing, and the different materials used for the various types of reactor, and the different levels of implementation of recent developments in fracture mechanics. Benchmark calculations were performed to improve user qualification and to reduce the user effect on the results of the analysis. This addressed generic PWR and WWER types of RPV, as well as sensitivity analyses. The complementary sensitivity analyses showed that the following factors significantly influenced the assessment: flaw size, shape, location and orientation, thermal hydraulic assumptions and material toughness. Applying national codes and procedures to the benchmark cases produced significantly different results in terms of allowable material toughness. This was mainly related to the safety factors used and the

  12. On the estimation of durability during thermal fatigue tests

    International Nuclear Information System (INIS)

    Vashunin, A.I.; Kotov, P.I.

    1981-01-01

    It is shown that during thermal fatigue tests under conditions of varying loading rigidity the value of stored one-sided deformation in a fracture zone tends to the limit value of material ductility. Holding at Tsub(max) is semicycle of compression increases irreversible deformation on value of Atausub(confer)sup(a), which does not depend on loading rigidity. It is established that the Use of curves of thermal fatigue as basic ones for determination of resistance of non-isothermal low-cycle fatigue is possible only at values of stored quasistatical damage, constituting less than 5% from available ductility [ru

  13. Shock wave and modeling study of the thermal decomposition reactions of pentafluoroethane and 2-H-heptafluoropropane.

    Science.gov (United States)

    Cobos, C J; Sölter, L; Tellbach, E; Troe, J

    2014-06-07

    The thermal decomposition reactions of CF3CF2H and CF3CFHCF3 have been studied in shock waves by monitoring the appearance of CF2 radicals. Temperatures in the range 1400-2000 K and Ar bath gas concentrations in the range (2-10) × 10(-5) mol cm(-3) were employed. It is shown that the reactions are initiated by C-C bond fission and not by HF elimination. Differing conclusions in the literature about the primary decomposition products, such as deduced from experiments at very low pressures, are attributed to unimolecular falloff effects. By increasing the initial reactant concentrations in Ar from 60 to 1000 ppm, a retardation of CF2 formation was observed while the final CF2 yields remained close to two CF2 per C2F5H or three CF2 per C3F7H decomposed. This is explained by secondary bimolecular reactions which lead to comparably stable transient species like CF3H, releasing CF2 at a slower rate. Quantum-chemical calculations and kinetic modeling help to identify the reaction pathways and provide estimates of rate constants for a series of primary and secondary reactions in the decomposition mechanism.

  14. Reversible thermal transition in GrpE, the nucleotide exchange factor of the DnaK heat-shock system.

    Science.gov (United States)

    Grimshaw, J P; Jelesarov, I; Schönfeld, H J; Christen, P

    2001-03-02

    DnaK, a Hsp70 acting in concert with its co-chaperones DnaJ and GrpE, is essential for Escherichia coli to survive environmental stress, including exposure to elevated temperatures. Here we explored the influence of temperature on the structure of the individual components and the functional properties of the chaperone system. GrpE undergoes extensive but fully reversible conformational changes in the physiologically relevant temperature range (transition midpoint at approximately 48 degrees C), as observed with both circular dichroism measurements and differential scanning calorimetry, whereas no thermal transitions occur in DnaK and DnaJ between 15 degrees C and 48 degrees C. The conformational changes in GrpE appear to be important in controlling the interconversion of T-state DnaK (ATP-liganded, low affinity for polypeptide substrates) and R-state DnaK (ADP-liganded, high affinity for polypeptide substrates). The rate of the T --> R conversion of DnaK due to DnaJ-triggered ATP hydrolysis follows an Arrhenius temperature dependence. In contrast, the rate of the R --> T conversion due to GrpE-catalyzed ADP/ATP exchange increases progressively less with increasing temperature and even decreases at temperatures above approximately 40 degrees C, indicating a temperature-dependent reversible inactivation of GrpE. At heat-shock temperatures, the reversible structural changes of GrpE thus shift DnaK toward its high-affinity R state.

  15. Effect of Rotation for Two-Temperature Generalized Thermoelasticity of Two-Dimensional under Thermal Shock Problem

    Directory of Open Access Journals (Sweden)

    Kh. Lotfy

    2013-01-01

    Full Text Available The theory of two-temperature generalized thermoelasticity based on the theory of Youssef is used to solve boundary value problems of two-dimensional half-space. The governing equations are solved using normal mode method under the purview of the Lord-Şhulman (LS and the classical dynamical coupled theory (CD. The general solution obtained is applied to a specific problem of a half-space subjected to one type of heating, the thermal shock type. We study the influence of rotation on the total deformation of thermoelastic half-space and the interaction with each other under the influence of two temperature theory. The material is homogeneous isotropic elastic half-space. The methodology applied here is use of the normal mode analysis techniques that are used to solve the resulting nondimensional coupled field equations for the two theories. Numerical results for the displacement components, force stresses, and temperature distribution are presented graphically and discussed. The conductive temperature, the dynamical temperature, the stress, and the strain distributions are shown graphically with some comparisons.

  16. The influence of chemistry concentration on the fracture risk of a reactor pressure vessel subjected to pressurized thermal shocks

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Pin-Chiun [Institute of Nuclear Engineering and Science, National Tsing-Hua University, Hsinchu 30013, Taiwan, ROC (China); Chou, Hsoung-Wei, E-mail: hwchou@iner.gov.tw [Institute of Nuclear Energy Research, Taoyuan 32546, Taiwan, ROC (China); Ferng, Yuh-Ming [Institute of Nuclear Engineering and Science, National Tsing-Hua University, Hsinchu 30013, Taiwan, ROC (China)

    2016-02-15

    Highlights: • Probabilistic fracture mechanics method was used to analyze a reactor pressure vessel. • Effects of copper and nickel contents on RPV fracture probability under PTS were investigated and discussed. • Representative PTS transients of Beaver Valley nuclear power plant were utilized. • The range of copper and nickel contents of the RPV materials were suggested. • With different embrittlement levels the dominated PTS category is different. - Abstract: The radiation embrittlement behavior of reactor pressure vessel shell is influenced by the chemistry concentration of metal materials. This paper aims to study the effects of copper and nickel content variations on the fracture risk of pressurized water reactor (PWR) pressure vessel subjected to pressurized thermal shock (PTS) transients. The probabilistic fracture mechanics (PFM) code, FAVOR, which was developed by the Oak Ridge National Laboratory in the United States, is employed to perform the analyses. A Taiwan domestic PWR pressure vessel assumed with varied copper and nickel contents of beltline region welds and plates is investigated in the study. Some PTS transients analyzed from Beaver Valley Unit 1 for establishing the U.S. NRC's new PTS rule are applied as the loading condition. It is found that the content variation of copper and nickel will significantly affect the radiation embrittlement and the fracture probability of PWR pressure vessels. The results can be regarded as the risk incremental factors for comparison with the safety regulation requirements on vessel degradation as well as a reference for the operation of PWR plants in Taiwan.

  17. Thermal Development Test of the NEXT PM1 Ion Engine

    Science.gov (United States)

    Anderson, John R.; Snyder, John S.; VanNoord, Jonathan L.; Soulas, George C.

    2010-01-01

    NASA's Evolutionary Xenon Thruster (NEXT) is a next-generation high-power ion propulsion system under development by NASA as a part of the In-Space Propulsion Technology Program. NEXT is designed for use on robotic exploration missions of the solar system using solar electric power. Potential mission destinations that could benefit from a NEXT Solar Electric Propulsion (SEP) system include inner planets, small bodies, and outer planets and their moons. This range of robotic exploration missions generally calls for ion propulsion systems with deep throttling capability and system input power ranging from 0.6 to 25 kW, as referenced to solar array output at 1 Astronomical Unit (AU). Thermal development testing of the NEXT prototype model 1 (PM1) was conducted at JPL to assist in developing and validating a thruster thermal model and assessing the thermal design margins. NEXT PM1 performance prior to, during and subsequent to thermal testing are presented. Test results are compared to the predicted hot and cold environments expected missions and the functionality of the thruster for these missions is discussed.

  18. Testing of High Thermal Cycling Stability of Low Strength Concrete as a Thermal Energy Storage Material

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2016-09-01

    Full Text Available Concrete has the potential to become a solution for thermal energy storage (TES integrated in concentrating solar power (CSP systems due to its good thermal and mechanical properties and low cost of material. In this study, a low strength concrete (C20 is tested at high temperatures up to 600 °C. Specimens are thermally cycled at temperatures in the range of 400–300 °C, 500–300 °C, and 600–300 °C, which TES can reach in operation. For comparison, specimens also cycled at temperature in the range of 400–25 °C (room temperature, 500–25 °C, and 600–25 °C. It is found from the test results that cracks are not observed on the surfaces of concrete specimens until the temperature is elevated up to 500 °C. There is mechanical deterioration of concrete after exposure to high temperature, especially to high thermal cycles. The residual compressive strength of concrete after 10 thermal cycles between 600 °C and 300 °C is about 58.3%, but the specimens remain stable without spalling, indicating possible use of low strength concrete as a TES material.

  19. The role of ductile ligaments and warm prestress on the re-initiation of fracture from a crack arrested during thermal shock

    International Nuclear Information System (INIS)

    Smith, E.

    1982-01-01

    The protection offered by warm prestress can be important for preserving a nuclear pressure vessel's integrity during a postulated emergency condition involving a loss of coolant, when the emergency core cooling water subjects the pressure vessel to a thermal shock. There are two aspects to the problem: (a) the initial extension of a defect into the vessel wall, and (b) the subsequent re-initiation of fracture at an arrested crack tip. This note considers the effect of warm prestress on the re-initiation of fracture from an arrested crack, and emphasizes the role of ductile ligaments. It is argued that the warm prestress concept is applicable, thus complementing the limited experimental results provided by the HSST Thermal Shock experimental programme. (orig.)

  20. Thermal-hydraulic tests for reactor safety system

    International Nuclear Information System (INIS)

    Chun, Se Young; Chung, Moon Ki; Baek, Won Pil

    2002-05-01

    Tests for the safety depressurization system, Sparger adopted for the Korean next generation reactor, APR1400 are carried out for several geometries with the B and C (Blowdown and Condensation) facility in the condition of high temperature and pressure and with a small test facility in the condition of atmospheric temperature and pressure. Tests for the critical heat flux are performed with the RCS(Reactor Coolant System) facility as well as with the Freon CHF Loop in the condition of high temperature and pressure. The atmospheric temperature and pressure facility is utilized for development of the high standard thermal hydraulic measurement technology. The optical method is developed to measure the local thermal-hydraulic behavior for the single and two-phase boiling phenomena

  1. Thermal test and analysis of a spent fuel storage cask

    International Nuclear Information System (INIS)

    Yamakawa, H.; Gomi, Y.; Ozaki, S.; Kosaki, A.

    1993-01-01

    A thermal test simulated with full-scale cask model for the normal storage was performed to verify the storage skill of the spent fuels of the cask. The maximum temperature at each point in the test was lower than the allowable temperature. The integrity of the cask was maintained. It was observed that the safety of containment system was also kept according to the check of the seal before and after the thermal test. Therefore it was shown that using the present skill, it is possible to store spent fuels in the dry-type cask safely. Moreover, because of the good agreement between analysis and experimental results, it was shown that the analysis model was successfully established to estimate the temperature distribution of the fuel cladding and the seal portion. (J.P.N.)

  2. Space nuclear thermal propulsion test facilities accommodation at INEL

    International Nuclear Information System (INIS)

    Hill, T.J.; Reed, W.C.; Welland, H.J.

    1993-01-01

    The U.S. Air Force (USAF) has proposed to develop the technology and demonstrate the feasibility of a particle bed reactor (PBR) propulsion system that could be used to power an advanced upper stage rocket engine. The U.S. Department of Energy (DOE) is cooperating with the USAF in that it would host the test facility if the USAF decides to proceed with the technology demonstration. Two DOE locations have been proposed for testing the PBR technology, a new test facility at the Nevada Test Site, or the modification and use of an existing facility at the Idaho National Engineering Laboratory. The preliminary evaluations performed at the INEL to support the PBR technology testing has been completed. Additional evaluations to scope the required changes or upgrade needed to make the proposed USAF PBR test facility meet the requirements for testing Space Exploration Initiative (SEI) nuclear thermal propulsion engines are underway

  3. Space nuclear thermal propulsion test facilities accommodation at INEL

    Science.gov (United States)

    Hill, Thomas J.; Reed, William C.; Welland, Henry J.

    1993-01-01

    The U.S. Air Force (USAF) has proposed to develop the technology and demonstrate the feasibility of a particle bed reactor (PBR) propulsion system that could be used to power an advanced upper stage rocket engine. The U.S. Department of Energy (DOE) is cooperating with the USAF in that it would host the test facility if the USAF decides to proceed with the technology demonstration. Two DOE locations have been proposed for testing the PBR technology, a new test facility at the Nevada Test Site, or the modification and use of an existing facility at the Idaho National Engineering Laboratory. The preliminary evaluations performed at the INEL to support the PBR technology testing has been completed. Additional evaluations to scope the required changes or upgrade needed to make the proposed USAF PBR test facility meet the requirements for testing Space Exploration Initiative (SEI) nuclear thermal propulsion engines are underway.

  4. Numerical modeling of Thermal Response Tests in Energy Piles

    Science.gov (United States)

    Franco, A.; Toledo, M.; Moffat, R.; Herrera, P. A.

    2013-05-01

    Nowadays, thermal response tests (TRT) are used as the main tools for the evaluation of low enthalpy geothermal systems such as heat exchangers. The results of TRT are used for estimating thermal conductivity and thermal resistance values of those systems. We present results of synthetic TRT simulations that model the behavior observed in an experimental energy pile system, which was installed at the new building of the Faculty of Engineering of Universidad de Chile. Moreover, we also present a parametric study to identify the most influent parameters in the performance of this type of tests. The modeling was developed using the finite element software COMSOL Multiphysics, which allows the incorporation of flow and heat transport processes. The modeled system consists on a concrete pile with 1 m diameter and 28 m deep, which contains a 28 mm diameter PEX pipe arranged in a closed circuit. Three configurations were analyzed: a U pipe, a triple U and a helicoid shape implemented at the experimental site. All simulations were run considering transient response in a three-dimensional domain. The simulation results provided the temperature distribution on the pile for a set of different geometry and physical properties of the materials. These results were compared with analytical solutions which are commonly used to interpret TRT data. This analysis demonstrated that there are several parameters that affect the system response in a synthetic TRT. For example, the diameter of the simulated pile affects the estimated effective thermal conductivity of the system. Moreover, the simulation results show that the estimated thermal conductivity for a 1 m diameter pile did not stabilize even after 100 hours since the beginning of the test, when it reached a value 30% below value used to set up the material properties in the simulation. Furthermore, we observed different behaviors depending on the thermal properties of concrete and soil. According to the simulations, the thermal

  5. James Webb Space Telescope Core 2 Test - Cryogenic Thermal Balance Test of the Observatorys Core Area Thermal Control Hardware

    Science.gov (United States)

    Cleveland, Paul; Parrish, Keith; Thomson, Shaun; Marsh, James; Comber, Brian

    2016-01-01

    The James Webb Space Telescope (JWST), successor to the Hubble Space Telescope, will be the largest astronomical telescope ever sent into space. To observe the very first light of the early universe, JWST requires a large deployed 6.5-meter primary mirror cryogenically cooled to less than 50 Kelvin. Three scientific instruments are further cooled via a large radiator system to less than 40 Kelvin. A fourth scientific instrument is cooled to less than 7 Kelvin using a combination pulse-tube Joule-Thomson mechanical cooler. Passive cryogenic cooling enables the large scale of the telescope which must be highly folded for launch on an Ariane 5 launch vehicle and deployed once on orbit during its journey to the second Earth-Sun Lagrange point. Passive cooling of the observatory is enabled by the deployment of a large tennis court sized five layer Sunshield combined with the use of a network of high efficiency radiators. A high purity aluminum heat strap system connects the three instrument's detector systems to the radiator systems to dissipate less than a single watt of parasitic and instrument dissipated heat. JWST's large scale features, while enabling passive cooling, also prevent the typical flight configuration fully-deployed thermal balance test that is the keystone of most space missions' thermal verification plans. This paper describes the JWST Core 2 Test, which is a cryogenic thermal balance test of a full size, high fidelity engineering model of the Observatory's 'Core' area thermal control hardware. The 'Core' area is the key mechanical and cryogenic interface area between all Observatory elements. The 'Core' area thermal control hardware allows for temperature transition of 300K to approximately 50 K by attenuating heat from the room temperature IEC (instrument electronics) and the Spacecraft Bus. Since the flight hardware is not available for test, the Core 2 test uses high fidelity and flight-like reproductions.

  6. Smart built-in test for nuclear thermal propulsion

    International Nuclear Information System (INIS)

    Lombrozo, P.C.

    1992-03-01

    Smart built-in test (BIT) technologies are envisioned for nuclear thermal propulsion spacecraft components which undergo constant irradiation and are therefore unsafe for manual testing. Smart BIT systems of automated/remote type allow component and system tests to be conducted; failure detections are directly followed by reconfiguration of the components affected. The 'smartness' of the BIT system in question involves the reduction of sensor counts via the use of multifunction sensors, the use of components as integral sensors, and the use of system design techniques which allow the verification of system function beyond component connectivity

  7. Research on signal processing of shock absorber test bench based on zero-phase filter

    Science.gov (United States)

    Wu, Yi; Ding, Guoqing

    2017-10-01

    The quality of force-displacement diagram is significant to help evaluate the performance of shock absorbers. Damping force sampling data is often interfered by Gauss white noise, 50Hz power interference and its harmonic wave during the process of testing; data de-noising has become the core problem of drawing true, accurate and real-time indicator diagram. The noise and interference can be filtered out through generic IIR or FIR low-pass filter, but addition phase lag of useful signal will be caused due to the inherent attribute of IIR and FIR filter. The paper uses FRR method to realize zero-phase digital filtering in a software way based on mutual cancellation of phase lag between the forward and reverse sequences after through the filter. High-frequency interference above 40Hz are filtered out completely and noise attenuation is more than -40dB, with no additional phase lag. The method is able to restore the true signal as far as possible. Theoretical simulation and practical test indicate high-frequency noises have been effectively inhibited in multiple typical speed cases, signal-to-noise ratio being greatly improved; the curve in indicator diagram has better smoothness and fidelity. The FRR algorithm has low computational complexity, fast running time, and can be easily transplanted in multiple platforms.

  8. Subgrain Rotation Behavior in Sn3.0Ag0.5Cu-Sn37Pb Solder Joints During Thermal Shock

    Science.gov (United States)

    Han, Jing; Tan, Shihai; Guo, Fu

    2018-01-01

    Ball grid array (BGA) samples were soldered on a printed circuit board with Sn37Pb solder paste to investigate the recrystallization induced by subgrain rotation during thermal shock. The composition of the solder balls was Sn3.0Ag0.5Cu-Sn37Pb, which comprised mixed solder joints. The BGA component was cross-sectioned before thermal shock. The microstructure and grain orientations were obtained by a scanning electron microscope equipped with an electron back-scattered diffraction system. Two mixed solder joints at corners of the BGA component were selected as the subjects. The results showed that recrystallization occurred at the corner of the solder joints after 200 thermal shock cycles. The recrystallized subgrains had various new grain orientations. The newly generated grain orientations were closely related to the initial grain orientations, which indicated that different subgrain rotation behaviors could occur in one mixed solder joint with the same initial grain orientation. When the misorientation angles were very small, the rotation axes were about Sn [100], [010] and [001], as shown by analyzing the misorientation angles and subgrain rotation axes, while the subgrain rotation behavior with large misorientation angles in the solder joints was much more complicated. As Pb was contained in the solder joints and the stress was concentrated on the corner of the mixed solder joints, concaves and cracks were formed. When the adjacent recrystallized subgrains were separated, and the process of the continuous recrystallization was limited.

  9. Thermal System Upgrade of the Space Environment Simulation Test Chamber

    Science.gov (United States)

    Desai, Ashok B.

    1997-01-01

    The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

  10. Hall Thruster Thermal Modeling and Test Data Correlation

    Science.gov (United States)

    Myers, James; Kamhawi, Hani; Yim, John; Clayman, Lauren

    2016-01-01

    The life of Hall Effect thrusters are primarily limited by plasma erosion and thermal related failures. NASA Glenn Research Center (GRC) in cooperation with the Jet Propulsion Laboratory (JPL) have recently completed development of a Hall thruster with specific emphasis to mitigate these limitations. Extending the operational life of Hall thursters makes them more suitable for some of NASA's longer duration interplanetary missions. This paper documents the thermal model development, refinement and correlation of results with thruster test data. Correlation was achieved by minimizing uncertainties in model input and recognizing the relevant parameters for effective model tuning. Throughout the thruster design phase the model was used to evaluate design options and systematically reduce component temperatures. Hall thrusters are inherently complex assemblies of high temperature components relying on internal conduction and external radiation for heat dispersion and rejection. System solutions are necessary in most cases to fully assess the benefits and/or consequences of any potential design change. Thermal model correlation is critical since thruster operational parameters can push some components/materials beyond their temperature limits. This thruster incorporates a state-of-the-art magnetic shielding system to reduce plasma erosion and to a lesser extend power/heat deposition. Additionally a comprehensive thermal design strategy was employed to reduce temperatures of critical thruster components (primarily the magnet coils and the discharge channel). Long term wear testing is currently underway to assess the effectiveness of these systems and consequently thruster longevity.

  11. Preliminary data evaluation for thermal insulation characterization testing

    International Nuclear Information System (INIS)

    DeClue, J.F.; Moses, S.D.; Tollefson, D.A.

    1991-01-01

    The purpose of Thermal Insulation Characterization Testing is to provide physical data to support certain assumptions and calculational techniques used in the criticality safety calculations in Section 6 of the Safety Analysis Reports for Packaging (SARPs) for drum-type packaging for Department of Energy's (DOE) Oak Ridge Y-12 Plant, managed by Martin Marietta Energy Systems, Inc. Results of preliminary data evaluation regarding the fire-test condition reveal that realistic weight loss consideration and residual material characterization in developing calculational models for the hypothetical accident condition is necessary in order to prevent placement of unduly conservative restrictions on shipping requirements as a result of overly conservative modeling. This is particularly important for fast systems. Determination of the geometric arrangement of residual material is of secondary importance. Both the methodology used to determine the minimum thermal insulation mass remaining after the fire test and the treatment of the thermal insulation in the criticality safety calculational models requires additional evaluation. Specific testing to be conducted will provide experimental data with which to validate the mass estimates and calculational modeling techniques for extrapolation to generic drum-type containers

  12. Thermal Vacuum Integrated System Test at B-2

    Science.gov (United States)

    Kudlac, Maureen T.; Weaver, Harold F.; Cmar, Mark D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Space Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility during pump down of the vacuum chamber, operation of the liquid nitrogen heat sink (or cold wall) and the infrared lamp array. A vacuum level of 1.3x10(exp -4)Pa (1x10(exp -6)torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (140deg R) along the entire inner surface of the vacuum chamber. The recently rebuilt and modernized infrared lamp array produced a nominal heat flux of 1.4 kW/sq m at a chamber diameter of 6.7 m (22 ft) and along 11 m (36 ft) of the chamber s cylindrical vertical interior. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface. The data acquired matched pretest predictions and demonstrated system functionality.

  13. Testing of Method for Assessing of Room Thermal Stability

    Directory of Open Access Journals (Sweden)

    Charvátová Hana

    2017-01-01

    Full Text Available The paper presents the interim results of our research on the developing methodological procedure which could be used for assessment of a thermal stability of buildings with regards to its thermal accumulative parameters. The principle of testing is based on a combination of computer simulation of cooled room model developed in COMSOL Multiphysics software and on theoretical calculations with respect to compliance with valid European and Czech technical standards used in building industry and architecture under conditions obtained by real measurement for the room to be tested. The presented example shows the effect of the heataccumulation properties of the outside wall insulation materials on the course of the cooling room for winter conditions.

  14. Solar Thermal Upper Stage Cryogen System Engineering Checkout Test

    Science.gov (United States)

    Olsen, A. D; Cady, E. C.; Jenkins, D. S.

    1999-01-01

    The Solar Thermal Upper Stage technology (STUSTD) program is a solar thermal propulsion technology program cooperatively sponsored by a Boeing led team and by NASA MSFC. A key element of its technology program is development of a liquid hydrogen (LH2) storage and supply system which employs multi-layer insulation, liquid acquisition devices, active and passive thermodynamic vent systems, and variable 40W tank heaters to reliably provide near constant pressure H2 to a solar thermal engine in the low-gravity of space operation. The LH2 storage and supply system is designed to operate as a passive, pressure fed supply system at a constant pressure of about 45 psia. During operation of the solar thermal engine over a small portion of the orbit the LH2 storage and supply system propulsively vents through the enjoy at a controlled flowrate. During the long coast portion of the orbit, the LH2 tank is locked up (unvented). Thus, all of the vented H2 flow is used in the engine for thrust and none is wastefully vented overboard. The key to managing the tank pressure and therefore the H2 flow to the engine is to manage and balance the energy flow into the LH2 tank with the MLI and tank heaters with the energy flow out of the LH2 tank through the vented H2 flow. A moderate scale (71 cu ft) LH2 storage and supply system was installed and insulated at the NASA MSFC Test Area 300. The operation of the system is described in this paper. The test program for the LH2 system consisted of two parts: 1) a series of engineering tests to characterize the performance of the various components in the system: and 2) a 30-day simulation of a complete LEO and GEO transfer mission. This paper describes the results of the engineering tests, and correlates these results with analytical models used to design future advanced Solar Orbit Transfer Vehicles.

  15. Innovative improvements of thermal response tests - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Poppei, J.; Schwarz, R. [AF-Colenco Ltd, Baden (Switzerland); Peron, H.; Silvani, C; Steinmann, G.; Laloui, L. [Swiss Federal Institute of Technology, Laboratoire de Mecanique des Sols, Lausanne (Switzerland); Wagner, R.; Lochbuehler, T.; Rohner, E. [Geowatt AG, Zuerich (Switzerland)

    2008-12-15

    This illustrated final report for Swiss Federal Office of Energy (SFOE) takes a look at innovative improvements to thermal response tests that are used to investigate the thermo-physical properties of the ground for the purpose of dimensioning borehole heat exchangers. Recent technical developments in the borehole investigation tools area provide a promising prerequisite for improved estimates of thermal conductivity. A mini-module developed at the Swiss Federal Institute of Technology EPFL which is suitable for fast and flexible thermal response testing is discussed as is a wireless miniature data logger for continuous temperature recordings in borehole heat exchangers up to a depth of 350 m. This allows high-resolution vertical temperature profiling in boreholes. International state-of-the-art methods are reviewed. The adaptations to the analytical methods necessary for the effective application of these tools are discussed and numerical methods available are looked at. The testing of the methods developed and their results are discussed, as is the influence of ground-water flow.

  16. Thermal Analysis of Low Layer Density Multilayer Insulation Test Results

    Science.gov (United States)

    Johnson, Wesley L.

    2011-01-01

    Investigation of the thermal performance of low layer density multilayer insulations is important for designing long-duration space exploration missions involving the storage of cryogenic propellants. Theoretical calculations show an analytical optimal layer density, as widely reported in the literature. However, the appropriate test data by which to evaluate these calculations have been only recently obtained. As part of a recent research project, NASA procured several multilayer insulation test coupons for calorimeter testing. These coupons were configured to allow for the layer density to be varied from 0.5 to 2.6 layer/mm. The coupon testing was completed using the cylindrical Cryostat-l00 apparatus by the Cryogenics Test Laboratory at Kennedy Space Center. The results show the properties of the insulation as a function of layer density for multiple points. Overlaying these new results with data from the literature reveals a minimum layer density; however, the value is higher than predicted. Additionally, the data show that the transition region between high vacuum and no vacuum is dependent on the spacing of the reflective layers. Historically this spacing has not been taken into account as thermal performance was calculated as a function of pressure and temperature only; however the recent testing shows that the data is dependent on the Knudsen number which takes into account pressure, temperature, and layer spacing. These results aid in the understanding of the performance parameters of MLI and help to complete the body of literature on the topic.

  17. Porosimetric, Thermal and Strength Tests of Aerated and Nonaerated Concretes

    Science.gov (United States)

    Strzałkowski, Jarosław; Garbalińska, Halina

    2017-10-01

    The paper presents the results of porosimetry tests of lightweight concretes, obtained with three research methods. Impact of different porosity structures on the basic thermal and strength properties was also evaluated. Tests were performed, using the pressure gauge method on fresh concrete mixes, as well as using the mercury porosimetry test and optic RapidAir method on specimens prepared from mature composites. The study was conducted on lightweight concretes, based on expanded clay aggregate and fly ash aggregate, in two variants: with non-aerated and aerated cement matrix. In addition, two reference concretes, based on normal aggregate, were prepared, also in two variants of matrix aeration. Changes in thermal conductivity λ and volumetric specific heat cv throughout the first three months of curing of the concretes were examined. Additionally, tests for compressive strength on cubic samples were performed during the first three months of curing. It was found that the pressure gauge method, performed on a fresh mix, gave lowered values of porosity, compared to the other methods. The mercury porosity tests showed high sensitivity in evaluation of pores smaller than 30μm. Unfortunately, this technique is not suitable for analysing pores greater than 300μm. On the other hand, the optical method proves good in evaluation of large pores, greater than 300μm. The paper also presents results of correlation of individual methods of porosity testing. A consolidated graph of the pore structure, derived from both mercury and optical methods, was presented, too. For the all of six tested concretes, differential graphs of porosity, prepared with both methods, show a very broad convergence. The thermal test results indicate usefulness of aeration of the cement matrix of the composites based on lightweight aggregates for the further reduction of the thermal conductivity coefficient λ of the materials. The lowest values of the λ coefficient were obtained for the aerated

  18. Molecular characterization of three heat shock protein 70 genes and their expression profiles under thermal stress in the citrus red mite.

    Science.gov (United States)

    Yang, Li-Hong; Jiang, Hong-Bo; Liu, Yong-Hua; Dou, Wei; Wang, Jin-Jun

    2012-04-01

    Three heat shock protein 70 family transcripts, named PcHsp70-1, PcHsp70-2 and PcHsp70-3, were isolated from the citrus red mite, Panonychus citri. PcHsp70-1, PcHsp70-2, and PcHsp70-3 contained an open reading frame of 1977, 1968, and 2028 nucleotides that encoded 658, 655 and 675 amino acid residues, respectively. Comparison of deduced amino acid sequences of PcHsp70-1 and PcHsp70-2 showed 86.34% identity, while the amino acid sequence of PcHsp70-3 was only 57.39 and 58.75% identical to that of PcHsp70-1 and PcHsp70-2, respectively. Sequences and phylogenetic analyses suggested that PcHsp70-1 and PcHsp70-2 were cytosolic Hsps, whereas PcHsp70-3 was located in ER (endoplasmic reticulum). To accurately validate mRNA expression profiles of the three Hsp70s under thermal stress conditions, seven housekeeping genes were evaluated. Alpha-tubulin and RpII were selected as optimal endogenous references for cold shock and heat shock conditions, respectively. Real-time quantitative RT-PCR revealed that only the mRNA expression of PcHsp70-2 was up-regulated under heat shocks, and all of the three Hsp70s were constitutively expressed under cold shocks. The results suggest that the three Hsp70s were more critical to coping with heat than cold shocks.

  19. 2-MW plasmajet facility thermal tests of concrete

    International Nuclear Information System (INIS)

    Goin, K.L.

    1977-07-01

    A test was made in the 2-Megawatt Plasmajet Facility to obtain experimental data relative to the thermal response of concrete to incident heat flux. 14.6 cm diameter by 8.0 cm long concrete cylinders were positioned in a supersonic flow of heated nitrogen from an arc heater. The end of the concrete cylinders impacted by the flow were subjected to heat fluxes in the range of 0.13 to 0.35 kW/cm 2 . Measurements included cold wall surface heat flux and pressure distributions, surface and indepth temperatures, ablation rates, and surface emission spectrographs. The test was part of the Sandia light water reactor safety research program and complements similar tests made in the Radiant Heat Facility at heat fluxes from 0.03 to 0.12 kW/cm 2 . A description of the tests and a tabulation of test data are included

  20. Fragmentation of Solid Materials Using Shock Tubes. Part 2: First Test Series in a Large Diameter Shock Tube

    Science.gov (United States)

    2017-12-01

    series used improved experimental techniques to reduce obscuration due to smoke and fire which, again, increased the number of observed fragments (iii...minimally-reinforced concrete masonry unit (CMU) wall, and one 8-ft x 8-ft reinforced concrete panel, each carefully fabricated and mounted to replicate...develops a vertical compressive force that resists horizontal flexure. Figure 4. A view of CMU sample set-up used in Test 20. 6 Figure 5

  1. Life Shocks and Crime: A Test of the “Turning Point” Hypothesis

    Science.gov (United States)

    Noonan, Kelly; Reichman, Nancy E.; Schwartz-Soicher, Ofira

    2012-01-01

    Other researchers have posited that important events in men’s lives—such as employment, marriage, and parenthood—strengthen their social ties and lead them to refrain from crime. A challenge in empirically testing this hypothesis has been the issue of self-selection into life transitions. This study contributes to this literature by estimating the effects of an exogenous life shock on crime. We use data from the Fragile Families and Child Wellbeing Study, augmented with information from hospital medical records, to estimate the effects of the birth of a child with a severe health problem on the likelihood that the infant’s father engages in illegal activities. We conduct a number of auxiliary analyses to examine exogeneity assumptions. We find that having an infant born with a severe health condition increases the likelihood that the father is convicted of a crime in the three-year period following the birth of the child, and at least part of the effect appears to operate through work and changes in parental relationships. These results provide evidence that life events can cause crime and, as such, support the “turning point” hypothesis. PMID:21660628

  2. Life shocks and crime: a test of the "turning point" hypothesis.

    Science.gov (United States)

    Corman, Hope; Noonan, Kelly; Reichman, Nancy E; Schwartz-Soicher, Ofira

    2011-08-01

    Other researchers have posited that important events in men's lives-such as employment, marriage, and parenthood-strengthen their social ties and lead them to refrain from crime. A challenge in empirically testing this hypothesis has been the issue of self-selection into life transitions. This study contributes to this literature by estimating the effects of an exogenous life shock on crime. We use data from the Fragile Families and Child Wellbeing Study, augmented with information from hospital medical records, to estimate the effects of the birth of a child with a severe health problem on the likelihood that the infant's father engages in illegal activities. We conduct a number of auxiliary analyses to examine exogeneity assumptions. We find that having an infant born with a severe health condition increases the likelihood that the father is convicted of a crime in the three-year period following the birth of the child, and at least part of the effect appears to operate through work and changes in parental relationships. These results provide evidence that life events can cause crime and, as such, support the "turning point" hypothesis.

  3. Vibration damage testing of thermal barrier fibrous blanket insulation

    International Nuclear Information System (INIS)

    Black, W.E.; Betts, W.S.

    1984-01-01

    GA Technologies is engaged in a long-term, multiphase program to determine the vibration characteristics of thermal barrier components leading to qualification of assemblies for High Temperature Gas-Cooled Reactor (HTGR) service. The phase of primary emphasis described herein is the third in a series of acoustic tests and uses as background the more elemental tests preceding it. Two sizes of thermal barrier coverplates with one fibrous blanket insulation type were tested in an acoustic environment at sound pressure levels up to 160 dB. Three tests were conducted using sinusoidal and random noise for up to 200 h duration at room temperature. Frequent inspections were made to determine the progression of degradation using definition of stages from a prior test program. Initially the insulation surface adjacent to the metallic seal sheets (noise side) assumed a chafed or polished appearance. This was followed by flattening of the as-received pillowed surface. This stage was followed by a depression being formed in the vicinity of the free edge of the coverplate. Next, loose powder from within the blanket and from fiber erosion accumulated in the depression. Prior experience showed that the next stage of deterioration exhibited a consolidation of the powder to form a local crust. In this test series, this last stage generally failed to materialize. Instead, surface holes generated by solid ceramic particulates (commonly referred to as 'shot') constituted the stage following powdering. With the exception of some manufacturing-induced anomalies, the final stage, namely, gross fiber breakup, did not occur. It is this last stage that must be prevented for the thermal barrier to maintain its integrity. (orig./GL)

  4. Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

    Directory of Open Access Journals (Sweden)

    N. Simos

    2016-11-01

    Full Text Available A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have been studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10^{20}  p/cm^{2}. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (∼5×10^{18}

  5. Thermal performance test of the hot gas ducts of HENDEL

    International Nuclear Information System (INIS)

    Hishida, M.; Kunitomi, K.; Ioka, I.; Umenishi, K.; Tanaka, T.; Shimomura, H.; Sanokawa, K.

    1984-01-01

    A hot gas duct provided with internal thermal insulation is to be used for high-temperature gas-cooled reactors (HTGR). This type of hot gas duct has not been used so far in industrial facilities, and only a couple of tests on such a large-scale model of a hot gas duct have been conducted. The present report deals with the results of the thermal performance of the single tube type hot gas ducts which are installed as parts of a helium engineering demonstration loop (HENDEL). Uniform temperature and heat flux distribution at the surface of the duct were observed, the experimental correlations being obtained for the effective thermal conductivity of the internal thermal insulation layer. The measured temperature distribution of the pressure tube was in good agreement with the calculation by a TRUMP heat transfer computer code. The temperature distribution of the inner tube of the co-axial hot gas duct was evaluated and no hot spot was detected. These results would be very valuable for the design and development of HTGR. (orig.)

  6. Simulation and test of the thermal behavior of pressure switch

    Science.gov (United States)

    Liu, Yifang; Chen, Daner; Zhang, Yao; Dai, Tingting

    2018-04-01

    Little, lightweight, low-power microelectromechanical system (MEMS) pressure switches offer a good development prospect for small, ultra-long, simple atmosphere environments. In order to realize MEMS pressure switch, it is necessary to solve one of the key technologies such as thermal robust optimization. The finite element simulation software is used to analyze the thermal behavior of the pressure switch and the deformation law of the pressure switch film under different temperature. The thermal stress releasing schemes are studied by changing the structure of fixed form and changing the thickness of the substrate, respectively. Finally, the design of the glass substrate thickness of 2.5 mm is used to ensure that the maximum equivalent stress is reduced to a quarter of the original value, only 154 MPa when the structure is in extreme temperature (80∘C). The test results show that after the pressure switch is thermally optimized, the upper and lower electrodes can be reliably contacted to accommodate different operating temperature environments.

  7. Design, fabrication and testing of a thermal diode

    Science.gov (United States)

    Swerdling, B.; Kosson, R.

    1972-01-01

    Heat pipe diode types are discussed. The design, fabrication and test of a flight qualified diode for the Advanced Thermal Control Flight Experiment (ATFE) are described. The review covers the use of non-condensable gas, freezing, liquid trap, and liquid blockage techniques. Test data and parametric performance are presented for the liquid trap and liquid blockage techniques. The liquid blockage technique was selected for the ATFE diode on the basis of small reservoir size, low reverse mode heat transfer, and apparent rapid shut-off.

  8. Final report on the reactor pressure vessel pressurized-thermal-shock. International comparative assessment study (RPV PTS ICAS)

    International Nuclear Information System (INIS)

    Sievers, J.; Schulz, H.; Bass, R.; Pugh, C.

    1999-10-01

    A summary of the recently completed International Comparative Assessment Study of Pressurized-Thermal-Shock in Reactor Pressure Vessels (RPV PTS ICAS) is presented here to record the results in actual and comparative fashions. Within the DFM task, where account was taken of material properties and boundary conditions, reasonable agreement was obtained in linear-elastic and elastic-plastic analysis results. Linear elastic analyses and J-estimation schemes were shown to provide conservative estimates of peak crack driving force when compared with those obtained using complex three-dimensional (3D) finite element analyses. Predictions of RT NDT generally showed less scatter than that observed in crack driving force calculations due to the fracture toughness curve used for fracture assessment in the transition temperature region. Observed scatter in some analytical results could be traced mainly to a misinterpretation of the thermal expansion coefficient data given for the cladding and base metal. Also, differences in some results could be due to a quality assurance problem related to procedures for approximating the loading data given in the Problem Statement. For the PFM task, linear-elastic solutions were again shown to be conservative with respect to elastic-plastic solutions (by a factor of 2 to 4). Scatter in solutions obtained using the same computer code was generally attributable to differences in input parameters, e.g. standard deviations for the initial value of RT NDT , as well as for nickel and copper content. In the THM task, while there was a high degree of scatter during the early part of the transient, reasonable agreement in results was obtained during the latter part of the transient. Generally, the scatter was due to differences in analytical approaches used by participants, which included correlation-based engineering methods, system codes and three-dimensional computational fluids dynamics codes. Some of the models used to simulate condensation

  9. Thermal vacuum test of space equipment: tests of SIR-2 instrument Chandrayaan-1 mission

    Science.gov (United States)

    Sitek, P.

    2008-11-01

    We describe the reasons of proceeding Thermal-Vacuum tests for space electronic. We will answer on following questions: why teams are doing TV tests, what kind of phases should be simulated, which situations are the most critical during TV tests, what kind of results should be expected, which errors can be detect. As an example, will be shown TV-test of SIR-2 instrument for Chandrayaan-1 moon mission.

  10. Numerical model for the thermal yield estimation of unglazed photovoltaic-thermal collectors using indoor solar simulator testing

    NARCIS (Netherlands)

    Katiyar, M.; van Balkom, M.W.; Rindt, C.C.M.; de Keizer, C.; Zondag, H.A.

    2017-01-01

    It is a common practice to test solar thermal and photovoltaic-thermal (PVT) collectors outdoors. This requires testing over several weeks to account for different weather conditions encountered throughout the year, which is costly and time consuming. The outcome of these tests is an estimation of

  11. Thermal-Hydraulic Tests for Reactor Core Safety

    International Nuclear Information System (INIS)

    Chun, Se Young; Chung, Moon Ki; Baek, Won Pil and others

    2005-04-01

    The reflood experiments for single rod annulus geometry have been performed to investigate the effect of spacer grid on thermal-hydraulics under reflood conditions. The reflood experimental loop for 6x6 rod bundle with a spacer grid developed in Korea has been provided. About 8000 data points for Post-CHF heat transfer have been obtained from the experiments About 1400 CHF data points for 3x3 Water and 5x5 Freon rod bundles have been obtained. The existing evaluation methodology for core safety under return-to-power conditions has been investigated using KAERI low flow CHF database. The hydraulic tests for turbulence mixing characteristics in subchannel of 5x5 rod bundle have been carried out using advanced measurement technique, LVD and the database for various spacer grids have been provided. In order to measure the turbulence mixing characteristics in details, the hydraulic loop with a magnified 5x5 rod bundle has been prepared. The database which was constructed through a systematic thermal hydraulic tests for the reflood phenomenon, CHF, Post-CHF is surely to be useful to the industry field, the regulation body and the development of thermal-hydraulic analysis code

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

    Energy Technology Data Exchange (ETDEWEB)

    Bradley K. Heath

    2014-03-01

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

  13. Acclimation-dependent expression of heat shock protein 70 in Pacific abalone ( Haliotis discus hannai Ino) and its acute response to thermal exposure

    Science.gov (United States)

    Li, Jiaqi; He, Qingguo; Sun, Hui; Liu, Xiao

    2012-01-01

    Heat shock protein 70 (Hsp70) is one important member of heat shock protein (Hsp) family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chronic and acute thermal exposure in Pacific abalone ( Haliotis discus hannai Ino). For the chronic exposure, abalones were maintained at 8, 12, 20, and 30°C for four months and their mRNA levels were measured. The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30°C-acclimated group, followed by the 8°C-acclimated group and then the 12°C- and 20°C-acclimated groups. After the long-term acclimation, gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8°C and 38°C for 30 min. Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure. The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups. Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions, through which they deal with the stress of thermal variations.

  14. Analysis and testing of an inner bypass magnetorheological damper for shock and vibration mitigation

    Science.gov (United States)

    Bai, Xian-Xu; Hu, Wei; Wereley, Norman M.

    2013-04-01

    Aiming at fundamentally improving the performance of MR dampers, including maximizing dynamic range (i.e., ratio of field-on to field-off damping force) while simultaneously minimizing field-off damping force, this study presents the principle of an inner bypass magnetorheological damper (IBMRD). The IBMRD is composed of a pair of twin tubes, i.e., the inner tube and outer concentric tube, a movable piston-shaft arrangement, and an annular MR fluid flow gap sandwiched between the concentric tubes. In the IBMRD, the inner tube serves simultaneously as the guide for the movable piston and the bobbin for the electromagnetic coil windings, and five active rings on the inner tube, annular MR fluid flow gap, and outer tube forms five closed magnetic circuits. The annular fluid flow gap is an inner bypass annular valve where the rheology of the MR fluids, and hence the damping force of the MR damper, is controlled. Based on the structural principle of the IBMRD, the IBMRD is configured and its finite element analysis (FEA) is implemented. After theoretically constructing the hydro-mechanical model for the IBMRD, its mathematical model is established using a Bingham-plastic nonlinear fluid model. The characteristics of the IBMRD are theoretically evaluated and compared to those of a conventional piston-bobbin MR damper with an identical active length and cylinder diameter. In order to validate the theoretical results predicted by the mathematical model, the prototype IBMRD is designed, fabricated, and tested. The servo-hydraulic testing machine (type: MTS 810) and rail-guided drop tower are used to provide sinusoidal displacement excitation and shock excitation to the IBMRD, respectively.

  15. Thermal-Chemical Model Of Subduction: Results And Tests

    Science.gov (United States)

    Gorczyk, W.; Gerya, T. V.; Connolly, J. A.; Yuen, D. A.; Rudolph, M.

    2005-12-01

    Seismic structures with strong positive and negative velocity anomalies in the mantle wedge above subduction zones have been interpreted as thermally and/or chemically induced phenomena. We have developed a thermal-chemical model of subduction, which constrains the dynamics of seismic velocity structure beneath volcanic arcs. Our simulations have been calculated over a finite-difference grid with (201×101) to (201×401) regularly spaced Eulerian points, using 0.5 million to 10 billion markers. The model couples numerical thermo-mechanical solution with Gibbs energy minimization to investigate the dynamic behavior of partially molten upwellings from slabs (cold plumes) and structures associated with their development. The model demonstrates two chemically distinct types of plumes (mixed and unmixed), and various rigid body rotation phenomena in the wedge (subduction wheel, fore-arc spin, wedge pin-ball). These thermal-chemical features strongly perturb seismic structure. Their occurrence is dependent on the age of subducting slab and the rate of subduction.The model has been validated through a series of test cases and its results are consistent with a variety of geological and geophysical data. In contrast to models that attribute a purely thermal origin for mantle wedge seismic anomalies, the thermal-chemical model is able to simulate the strong variations of seismic velocity existing beneath volcanic arcs which are associated with development of cold plumes. In particular, molten regions that form beneath volcanic arcs as a consequence of vigorous cold wet plumes are manifest by > 20% variations in the local Poisson ratio, as compared to variations of ~ 2% expected as a consequence of temperature variation within the mantle wedge.

  16. Nuclear thermal rocket nozzle testing and evaluation program

    International Nuclear Information System (INIS)

    Davidian, K.O.; Kacynski, K.J.

    1993-01-01

    Performance characteristics of the Nuclear Thermal Rocket can be enhanced through the use of unconventional nozzles as part of the propulsion system. In this report, the Nuclear Thermal Rocket nozzle testing and evaluation program being conducted at the NASA Lewis Research Center is outlined and the advantages of a plug nozzle are described. A facility description, experimental designs and schematics are given. Results of pretest performance analyses show that high nozzle performance can be attained despite substantial nozzle length reduction through the use of plug nozzles as compared to a convergent-divergent nozzle. Pretest measurement uncertainty analyses indicate that specific impulse values are expected to be within plus or minus 1.17%

  17. Shear and Thermal Testing of Adhesives for VELO Upgrade

    CERN Document Server

    De Capua, Stefano; Klaver, Suzanne; Parkes, Chris; Rodriguez Perez, Pablo; Shtipliyski, Antoni; Stelmasiak, Guy James

    2016-01-01

    As part of the R&D process of the LHCb VELO Upgrade, a study has been performed on the thermal and mechanical performance of the adhesives Stycast 2850FT, 3M 9461P, and Araldite 2011. One or more of these adhesives could be used to attach the ASICs and hybrids to the microchannel cooling substrate. Samples were irradiated at up to the maximum dose expected at the upgrade. Shear tests of the samples were made and a suitable performance obtained from all glues. Some failures were encountered with Stycast 2850FT glued samples and this is attributed to the sample preparation. The relative thermal conductivities of the adhesives were also determined by measuring the relative temperature difference across a glued joint while one side is heated.

  18. Proportional and Integral Thermal Control System for Large Scale Heating Tests

    Science.gov (United States)

    Fleischer, Van Tran

    2015-01-01

    The National Aeronautics and Space Administration Armstrong Flight Research Center (Edwards, California) Flight Loads Laboratory is a unique national laboratory that supports thermal, mechanical, thermal/mechanical, and structural dynamics research and testing. A Proportional Integral thermal control system was designed and implemented to support thermal tests. A thermal control algorithm supporting a quartz lamp heater was developed based on the Proportional Integral control concept and a linearized heating process. The thermal control equations were derived and expressed in terms of power levels, integral gain, proportional gain, and differences between thermal setpoints and skin temperatures. Besides the derived equations, user's predefined thermal test information generated in the form of thermal maps was used to implement the thermal control system capabilities. Graphite heater closed-loop thermal control and graphite heater open-loop power level were added later to fulfill the demand for higher temperature tests. Verification and validation tests were performed to ensure that the thermal control system requirements were achieved. This thermal control system has successfully supported many milestone thermal and thermal/mechanical tests for almost a decade with temperatures ranging from 50 F to 3000 F and temperature rise rates from -10 F/s to 70 F/s for a variety of test articles having unique thermal profiles and test setups.

  19. Design and testing of a magnetorheological damper to control both vibration and shock loads for a vehicle crew seat

    Science.gov (United States)

    Becnel, Andrew; Hu, Wei; Hiemenz, Gregory J.; Wereley, Norman M.

    2010-04-01

    A magnetorheological shock absorber (MRSA) prototype is designed, fabricated and tested to integrate semiactive shock and vibration mitigation technology into the existing Expeditionary Fighting Vehicle (EFV) forward seating positions. Utilizing Bingham-Plastic (BP) constitutive fluid relationships and a steady state fluid flow model, the MR valve parameters are determined using magnetic circuit analysis, and subsequently validated via electromagnetic finite element analysis (FEA). Low speed (up to 0.9 m/s) simulations of normal vibration mode operation are conducted on the MRSA prototype using single frequency sinusoidal displacements by a servohydraulic testing machine. The high speed (up to 2.2 m/s) design procedure is verified by using a rail-guided drop test stand to impact a known payload mass onto the damper shaft. A refined hydromechanical model of the MRSA under both cyclic and impact loadings is developed and validated using the measured test data. This ratedependent, mechanisms-based model predicts the time response of the MRSA under both loading conditions. The hydromechanical analysis marks a significant improvement over previous linear models. Key design considerations for the MRSA to accommodate both vibration and shock spectra using a single MR device are presented.

  20. Multi-parameter fibre Bragg grating sensor-array for thermal vacuum cycling test

    Science.gov (United States)

    Cheng, L.; Ahlers, B.; Toet, P.; Casarosa, G.; Appolloni, M.

    2017-11-01

    strain transducer to generate strain via a dedicated feed through in the chamber. Thermocouples are used to log the temperature for comparison to the temperature FBG sensor. Extreme temperature ranges from -150°C and +70°C at a pressure down to 10-4 Pa (10-6 mbar) are covered as well as testing under ambient conditions. In total five thermal cycles during a week test are performed. The FBG temperature sensor test results performed in the ESA/ESTEC TV chamber reveal high reproducibility (within 1 °C) within the test temperature range without any evidence of hysteresis. Differences are detected to the previous calibration curve. Investigation is performed to find the cause of the discrepancy. Differences between the test set-ups are identified. Equipment of the TNO test is checked and excluded to be the cause. Additional experiments are performed. The discrepancy is most likely caused by a 'thermal shock' due to rapid cooling down to LN2 temperature, which results in a wavelength shift. Test data of the FBG strain sensor is analysed. The read-out of the FBG strain sensor varies with the temperature during the test. This can be caused by temperature induced changes in the mechanical setup (fastening of the mechanical parts) or impact of temperature to the mechanical strain transfer to the FBG. Improvements are identified and recommendations given for future activities.

  1. Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report

    Science.gov (United States)

    Wieland, P. O.; Hawk, H. D.

    2001-01-01

    During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

  2. New test of bow-shock models of Herbig-Haro objects

    International Nuclear Information System (INIS)

    Raga, A.C.; Bohm, K.H.; Solf, J.; Max-Planck-Institut fuer Astronomie, Heidelberg, West Germany)

    1986-01-01

    Long-slit, high-resolution spectroscopy of the Herbig-Haro oject HH 32 has shown that the emission-line profiles in all four condensations A, B, C, and D show high- and low-velocity components. The spatial maxima of these two components are always arranged in a double-layer pattern, with the maximum of the high-velocity component 0.6-1.0 arcsecs closer to the central star (AS 353A) than the low-velocity maximum. A study of the emission-line profiles predicted from a model of a radiating bow shock shows that such a double-layer structure appears naturally for this type of flow. In this case both the high-velocity and the low-velocity components come from the post-shock gas, in agreement with the theoretical prediction that it should be very difficult to detect the pre-shock gas observationally. The present results agree qualitatively well with observations of HH 32, strengthening the case for a bow-shock interpretation of this Herbig-Haro object. It is shown that the double-layer effect will be more easily observable for bow shocks which move at a relatively large angle with respect to the plane of the sky (i.e., for Herbig-Haro objects which have large radial velocities). 31 references

  3. Evolution of thermal-hydraulics testing in EBR-II

    International Nuclear Information System (INIS)

    Golden, G.H.; Planchon, H.P.; Sackett, J.I.; Singer, R.M.

    1987-01-01

    A thermal-hydraulics testing and modeling program has been underway at the Experimental Breeder Reactor-II (EBR-II) for 12 years. This work culminated in two tests of historical importance to commercial nuclear power, a loss of flow without scram and a loss of heat sink wihout scram, both from 100% initial power. These tests showed that natural processes will shut EBR-II down and maintain cooling without automatic control rod action or operator intervention. Supporting analyses indicate that these results are characteristic of a range of sizes of liquid metal cooled reactors (LMRs), if these reactors use metal driver fuel. This type of fuel is being developed as part of the Integral Fast Reactor Program at Argonne National Laboratory. Work is now underway at EBR-II to exploit the inherent safety of metal-fueled LMRs with regard to development of improved plant control strategies. (orig.)

  4. Tests of a thermal acoustic shield with a supersonic jet

    Science.gov (United States)

    Pickup, N.; Mangiarotty, R. A.; Okeefe, J. V.

    1981-10-01

    Fuel economy is a key element in the design of a future supersonic transport (SST). Variable cycle engines are being developed to provide the most economic combination of characteristics for a range of cruise speeds extending from subsonic speeds for overland flights to the supersonic cruise speeds. For one of these engines, the VCE-702, some form of noise suppression is needed for takeoff/sideline thrusts. The considered investigation is primarily concerned with scale model static tests of one particular concept for achieving that reduction, the thermal acoustic shield (TAS), which could also benefit other candidate SST engines. Other noise suppression devices being considered for SST application are the coannular nozzle, an internally ventilated nozzle, and mechanical suppressors. A test description is provided, taking into account the model configurations, the instrumentation, the test jet conditions, and aspects of screech noise control. Attention is given to shield thickness effects, a spectrum analysis, suppression and performance loss, and installed performance.

  5. Influence of thermal conditioning media on Charpy specimen test temperature

    International Nuclear Information System (INIS)

    Nanstad, R.K.; Swain, R.L.; Berggren, R.G.

    1989-01-01

    The Charpy V-notch (CVN) impact test is used extensively for determining the toughness of structural materials. Research programs in many technologies concerned with structural integrity perform such testing to obtain Charpy energy vs temperature curves. American Society for Testing and Materials Method E 23 includes rather strict requirements regarding determination and control of specimen test temperature. It specifies minimum soaking times dependent on the use of liquids or gases as the medium for thermally conditioning the specimen. The method also requires that impact of the specimen occur within 5 s removal from the conditioning medium. It does not, however, provide guidance regarding choice of conditioning media. This investigation was primarily conducted to investigate the changes in specimen temperature which occur when water is used for thermal conditioning. A standard CVN impact specimen of low-alloy steel was instrumented with surface-mounted and embedded thermocouples. Dependent on the media used, the specimen was heated or cooled to selected temperatures in the range -100 to 100 degree C using cold nitrogen gas, heated air, acetone and dry ice, methanol and dry ice, heated oil, or heated water. After temperature stabilization, the specimen was removed from the conditioning medium while the temperatures were recorded four times per second from all thermocouples using a data acquisition system and a computer. The results show that evaporative cooling causes significant changes in the specimen temperatures when water is used for conditioning. Conditioning in the other media did not result in such significant changes. The results demonstrate that, even within the guidelines of E 23, significant test temperature changes can occur which may substantially affect the Charpy impact test results if water is used for temperature conditioning. 7 refs., 11 figs

  6. Hall Thruster Thermal Modeling and Test Data Correlation

    Science.gov (United States)

    Myers, James

    2016-01-01

    HERMeS - Hall Effect Rocket with Magnetic Shielding. Developed through a joint effort by NASA/GRC and the Jet Propulsion Laboratory (JPL). Design goals: High power (12.5 kW) high Isp (3000 sec), high efficiency (> 60%), high throughput (10,000 kg), reduced plasma erosion and increased life (5 yrs) to support Asteroid Redirect Robotic Mission (ARRM). Further details see "Performance, Facility Pressure Effects and Stability Characterization Tests of NASAs HERMeS Thruster" by H. Kamhawi and team. Hall Thrusters (HT) inherently operate at elevated temperatures approx. 600 C (or more). Due to electric magnetic (E x B) fields used to ionize and accelerate propellant gas particles (i.e., plasma). Cooling is largely limited to radiation in vacuum environment.Thus the hardware components must withstand large start-up delta-T's. HT's are constructed of multiple materials; assorted metals, non-metals and ceramics for their required electrical and magnetic properties. To mitigate thermal stresses HT design must accommodate the differential thermal growth from a wide range of material Coef. of Thermal Expansion (CTEs). Prohibiting the use of some bolted/torqued interfaces.Commonly use spring loaded interfaces, particularly at the metal-to-ceramic interfaces to allow for slippage.However most component interfaces must also effectively conduct heat to the external surfaces for dissipation by radiation.Thus contact pressure and area are important.

  7. Designing and testing computer based screening engine for severe sepsis/septic shock.

    Science.gov (United States)

    Herasevich, V; Afessa, B; Chute, C G; Gajic, O

    2008-11-06

    This study addresses the role of a sepsis "sniffer", an automatic screening tool for the timely identification of patients with severe sepsis/septic shock, based electronic medical records. During the two months prospective implementation in a medical intensive care unit, 37 of 320 consecutive patients developed severe sepsis/septic shock. The sniffer demonstrated a sensitivity of 48% and specificity of 86%, and positive predictive value 32%. Further improvements are needed prior to the implementation of sepsis sniffer in clinical practice and research.

  8. Effect of molar ratios of MgO/Al{sub 2}O{sub 3} on the sintering behavior and thermal shock resistance of MgOAl{sub 2}O{sub 3}SiO{sub 2} composite ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Dong, E-mail: 1078155409@qq.com [School of High Temperature Materials and Magnesium Resource Engineering, University of Science and Technology Liaoning, Anshan 114051 (China); Luo, Xudong, E-mail: luoxudongs@aliyun.com [School of High Temperature Materials and Magnesium Resource Engineering, University of Science and Technology Liaoning, Anshan 114051 (China); Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhang, Guodong [School of High Temperature Materials and Magnesium Resource Engineering, University of Science and Technology Liaoning, Anshan 114051 (China); Xie, Zhipeng [Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2017-01-01

    In order to determine the relationship between the property of MgOAl{sub 2}O{sub 3}SiO{sub 2} composite ceramics and molar ratios of MgO/Al{sub 2}O{sub 3}, especially the sintering behavior and thermal shock resistance, the MgOAl{sub 2}O{sub 3}SiO{sub 2} composite ceramics were fabricated with micro-size MgO, Al{sub 2}O{sub 3} powder and nano-size SiO{sub 2} as main raw materials. The sample was characterized by phase analysis, densification and thermal shock times. Moreover, field emission scanning electron microscope was also conducted to study microstructure of the samples before and after thermal shock. Effect of different molar ratios of MgO/Al{sub 2}O{sub 3} on the sintering behavior and thermal shock resistance of composite ceramics were investigated. The results showed that the sample possess better sintering behavior and thermal shock resistance with the molar ratio of MgO/Al{sub 2}O{sub 3} equal to 2/1. Grains of periclase and spinel were directly bonded together, resulting in a dense and compact microstructure, and the bulk density of obtained sample reached 3.4 g/cm{sup 3}. The microstructure of sample after thermal shock revealed that the crack propagation path was deflected and bifurcated, the main-crack propagation was restricted and more fracture energy was consumed, the thermal shock resistance of composite ceramics was greatly improved. - Highlights: • Effect of MgO/Al{sub 2}O{sub 3} on the composite ceramic was firstly researched with 1 mol% SiO{sub 2}. • Microcracks for a short distance by interlinking can eliminate the crack propagation. • The composite ceramic have optimal synthetic property with MgO/Al{sub 2}O{sub 3} was 2/1.

  9. Analytic tests and their relation to jet fuel thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Heneghan, S.P.; Kauffman, R.E. [Univ. of Dayton Research Institute, OH (United States)

    1995-05-01

    The evaluation of jet fuel thermal stability (TS) by simple analytic procedures has long been a goal of fuels chemists. The reason is obvious: if the analytic chemist can determine which types of material cause his test to respond, the refiners will know which materials to remove to improve stability. Complicating this quest is the lack of an acceptable quantitative TS test with which to compare any analytic procedures. To circumvent this problem, we recently compiled the results of TS tests for 12 fuels using six separate test procedures. The results covering a range of flow and temperature conditions show that TS is not as dependent on test conditions as previously thought. Also, comparing the results from these tests with several analytic procedures shows that either a measure of the number of phenols or the total sulfur present in jet fuels is strongly indicative of the TS. The phenols have been measured using a cyclic voltammetry technique and the polar material by gas chromatography (atomic emission detection) following a solid phase extraction on silica gel. The polar material has been identified as mainly phenols (by mass spectrometry identification). Measures of the total acid number or peroxide concentration have little correlation with TS.

  10. Ground test facilities for evaluating nuclear thermal propulsion engines and fuel elements

    International Nuclear Information System (INIS)

    Allen, G.C.; Beck, D.F.; Harmon, C.D.; Shipers, L.R.

    1992-01-01

    Interagency panels evaluating nuclear thermal propulsion development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and design issues of a proposed ground test complex for evaluating nuclear thermal propulsion engines and fuel elements being developed for the Space Nuclear Thermal Propulsion (SNTP) program. 2 refs

  11. Frequency and Prognostic Significance of Abnormal Liver Function Tests in Patients With Cardiogenic Shock

    DEFF Research Database (Denmark)

    Jäntti, Toni; Tarvasmäki, Tuukka; Harjola, Veli Pekka

    2017-01-01

    Cardiogenic shock (CS) is a cardiac emergency often leading to multiple organ failure and death. Assessing organ dysfunction and appropriate risk stratification are central for the optimal management of these patients. The purpose of this study was to assess the prevalence of abnormal liver funct...

  12. Test program element II blanket and shield thermal-hydraulic and thermomechanical testing, experimental facility survey

    International Nuclear Information System (INIS)

    Ware, A.G.; Longhurst, G.R.

    1981-12-01

    This report presents results of a survey conducted by EG and G Idaho to determine facilities available to conduct thermal-hydraulic and thermomechanical testing for the Department of Energy Office of Fusion Energy First Wall/Blanket/Shield Engineering Test Program. In response to EG and G queries, twelve organizations (in addition to EG and G and General Atomic) expressed interest in providing experimental facilities. A variety of methods of supplying heat is available

  13. Test program element II blanket and shield thermal-hydraulic and thermomechanical testing, experimental facility survey

    Energy Technology Data Exchange (ETDEWEB)

    Ware, A.G.; Longhurst, G.R.

    1981-12-01

    This report presents results of a survey conducted by EG and G Idaho to determine facilities available to conduct thermal-hydraulic and thermomechanical testing for the Department of Energy Office of Fusion Energy First Wall/Blanket/Shield Engineering Test Program. In response to EG and G queries, twelve organizations (in addition to EG and G and General Atomic) expressed interest in providing experimental facilities. A variety of methods of supplying heat is available.

  14. An on-road shock and vibration response test series utilizing worst case and statistical analysis techniques

    International Nuclear Information System (INIS)

    Cap, J.S.

    1997-01-01

    Defining the maximum expected shock and vibration responses for an on-road truck transportation environment is strongly dependent on the amount of response data that can be obtained. One common test scheme consists of measuring response data over a relatively short prescribed road course and then reviewing that data to obtain the maximum response levels. The more mathematically rigorous alternative is to collect an unbiased ensemble of response data during a long road trip. This paper compares data gathered both ways during a recent on-road certification test for a tractor trailer van being designed by Sandia

  15. 10-MWe pilot-plant-receiver panel test requirements document solar thermal test facility

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-25

    Testing plans for a full-scale test receiver panel and supporting hardware which essentially duplicate both physically and functionally, the design planned for the Barstow Solar Pilot Plant are presented. Testing is to include operation during normal start and shutdown, intermittent cloud conditions, and emergencies to determine the panel's transient and steady state operating characteristics and performance under conditions equal to or exceeding those expected in the pilot plant. The effects of variations of input and output conditions on receiver operation are also to be investigated. Test hardware are described, including the pilot plant receiver, the test receiver assembly, receiver panel, flow control, electrical control and instrumentation, and structural assembly. Requirements for the Solar Thermal Test Facility for the tests are given. The safety of the system is briefly discussed, and procedures are described for assembly, installation, checkout, normal and abnormal operations, maintenance, removal and disposition. Also briefly discussed are quality assurance, contract responsibilities, and test documentation. (LEW)

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  17. Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

    Science.gov (United States)

    Bradley, David E.; Mireles, Omar R.; Hickman, Robert R.

    2011-01-01

    Deep space missions with large payloads require high specific impulse (Isp) and relatively high thrust in order to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average Isp. Nuclear thermal rockets (NTR) capable of high Isp thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high temperature hydrogen exposure on fuel elements is limited. The primary concern is the mechanical failure of fuel elements which employ high-melting-point metals, ceramics or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via non-contact RF heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

  18. Intelligent MRTD testing for thermal imaging system using ANN

    Science.gov (United States)

    Sun, Junyue; Ma, Dongmei

    2006-01-01

    The Minimum Resolvable Temperature Difference (MRTD) is the most widely accepted figure for describing the performance of a thermal imaging system. Many models have been proposed to predict it. The MRTD testing is a psychophysical task, for which biases are unavoidable. It requires laboratory conditions such as normal air condition and a constant temperature. It also needs expensive measuring equipments and takes a considerable period of time. Especially when measuring imagers of the same type, the test is time consuming. So an automated and intelligent measurement method should be discussed. This paper adopts the concept of automated MRTD testing using boundary contour system and fuzzy ARTMAP, but uses different methods. It describes an Automated MRTD Testing procedure basing on Back-Propagation Network. Firstly, we use frame grabber to capture the 4-bar target image data. Then according to image gray scale, we segment the image to get 4-bar place and extract feature vector representing the image characteristic and human detection ability. These feature sets, along with known target visibility, are used to train the ANN (Artificial Neural Networks). Actually it is a nonlinear classification (of input dimensions) of the image series using ANN. Our task is to justify if image is resolvable or uncertainty. Then the trained ANN will emulate observer performance in determining MRTD. This method can reduce the uncertainties between observers and long time dependent factors by standardization. This paper will introduce the feature extraction algorithm, demonstrate the feasibility of the whole process and give the accuracy of MRTD measurement.

  19. Space Shuttle Program (SSP) Shock Test and Specification Experience for Reusable Flight Hardware Equipment

    Science.gov (United States)

    Larsen, Curtis E.

    2012-01-01

    As commercial companies are nearing a preliminary design review level of design maturity, several companies are identifying the process for qualifying their multi-use electrical and mechanical components for various shock environments, including pyrotechnic, mortar firing, and water impact. The experience in quantifying the environments consists primarily of recommendations from Military Standard-1540, Product Verification Requirement for Launch, Upper Stage, and Space Vehicles. Therefore, the NASA Engineering and Safety Center (NESC) formed a team of NASA shock experts to share the NASA experience with qualifying hardware for the Space Shuttle Program (SSP) and other applicable programs and projects. Several team teleconferences were held to discuss past experience and to share ideas of possible methods for qualifying components for multiple missions. This document contains the information compiled from the discussions

  20. Review of Nuclear Thermal Propulsion Ground Test Options

    Science.gov (United States)

    Coote, David J.; Power, Kevin P.; Gerrish, Harold P.; Doughty, Glen

    2015-01-01

    High efficiency rocket propulsion systems are essential for humanity to venture beyond the moon. Nuclear Thermal Propulsion (NTP) is a promising alternative to conventional chemical rockets with relatively high thrust and twice the efficiency of highest performing chemical propellant engines. NTP utilizes the coolant of a nuclear reactor to produce propulsive thrust. An NTP engine produces thrust by flowing hydrogen through a nuclear reactor to cool the reactor, heating the hydrogen and expelling it through a rocket nozzle. The hot gaseous hydrogen is nominally expected to be free of radioactive byproducts from the nuclear reactor; however, it has the potential to be contaminated due to off-nominal engine reactor performance. NTP ground testing is more difficult than chemical engine testing since current environmental regulations do not allow/permit open air testing of NTP as was done in the 1960's and 1970's for the Rover/NERVA program. A new and innovative approach to rocket engine ground test is required to mitigate the unique health and safety risks associated with the potential entrainment of radioactive waste from the NTP engine reactor core into the engine exhaust. Several studies have been conducted since the ROVER/NERVA program in the 1970's investigating NTP engine ground test options to understand the technical feasibility, identify technical challenges and associated risks and provide rough order of magnitude cost estimates for facility development and test operations. The options can be divided into two distinct schemes; (1) real-time filtering of the engine exhaust and its release to the environment or (2) capture and storage of engine exhaust for subsequent processing.

  1. Preliminary interpretation of thermal data from the Nevada Test Site

    International Nuclear Information System (INIS)

    Sass, J.H.; Lachenbruch, A.H.

    1982-01-01

    Analysis of data from 60 wells in and around the Nevada Test Site, including 16 in the Yucca Mountain area, indicates a thermal regime characterized by large vertical and lateral gradients in heat flow. Estimates of heat flow indicate considerable variation on both regional and local scales. The variations are attributable primarily to hydrologic processes involving interbasin flow with a vertical component of (seepage) velocity (volume flux) of a few mm/yr. Apart from indicating a general downward movement of water at a few mm/yr, the reults from Yucca Mountain are as yet inconclusive. The purpose of the study was to determine the suitability of the area for proposed repository sites

  2. Integral test of JENDL-3.3 for thermal reactors

    International Nuclear Information System (INIS)

    Okumura, Keisuke; Mori, Takamasa

    2003-01-01

    Criticality benchmark testing was carried out for 59 experiments in various thermal reactors using a continues-energy Monte Carlo code MVP and its different libraries generated from JENDL-3.2, JENDL-3.3, JEF-2.2 and ENDF/B-VI (R8). From the benchmark results, we can say JENDL-3.3 generally gives better k eff values compared with other nuclear data libraries. However, further modification of JENDL-3.3 is expected to solve the following problems: 1) systematic underestimation of k eff depending on 235 U enrichment for the cores with low (less than 3wt.%) enriched uranium fueled cores, 2) dependence of C/E value of k eff on neutron spectrum and plutonium composition for MOX fueled cores. These are common problems for all of the nuclear data libraries used in this study. (author)

  3. Benchmark tests for fast and thermal reactor applications

    International Nuclear Information System (INIS)

    Seki, Yuji

    1984-01-01

    Integral tests of JENDL-2 library for fast and thermal reactor applications are reviewed including relevant analyses of JUPITER experiments. Criticality and core center characteristics were tested with one-dimensional models for a total of 27 fast critical assemblies. More sofisticated problems such as reaction rate distributions, control rod worths and sodium void reactivities were tested using two-dimensional models for MOZART and ZPPR-3 assemblies. Main observations from the fast core benchmark tests are as follows. 1) The criticality is well predicted; the average C/E value is 0.999+-0.008 for uranium cores and 0.997+-0.005 for plutonium cores. 2) The calculation underpredicts the reaction rate ratio 239 Pusub(fis)/ 235 Usub(fis) by 3% and overpredicts 238 Usub(cap)/ 239 Pusub(fis) by 6%. The results are consistent with those of JUPITER analyses. 3) The reaction rate distributions in the cores of prototype size are well predicted within +-3%. In larger JUPITER cores, however, the C/E value increases with the radial distance from the core center up to 6% at the outer core edge. 4) The prediction of control rod worths is satisfactory; C/E values are within the range from 0.92 to 0.97 with no apparent dependence on 10 B enrichment and the number of control rods inserted. Spatial dependence of C/E is also observed in the JUPITER cores. 5) The sodium void reactivity is overpredicted by 30% to 50% to the positive side. 1) The criticality is well predicted, as is the same in the fast core tests; the average C/E is 0.997+-0.003. 2) The calculation overpredicts 238 Usub(fis)/ 235 Usub(fis) by 3% to 6%, which shows the same tendency as in the small and medium size fast assemblies. The 238 Usub(cap)/ 235 Usub(fis) ratio is well predicted in the thermal cores. The calculated reaction rate ratios of 232 Th deviate from the measurements by 10% to 15%. (author)

  4. Modernisation of a test rig for determination of vehicle shock absorber characteristics by considering vehicle suspension elements and unsprung masses

    Science.gov (United States)

    Maniowski, M.; Para, S.; Knapczyk, M.

    2016-09-01

    This paper presents a modernization approach of a standard test bench for determination of damping characteristics of automotive shock absorbers. It is known that the real-life work conditions of wheel-suspension dampers are not easy to reproduce in laboratory conditions, for example considering a high frequency damper response or a noise emission. The proposed test bench consists of many elements from a real vehicle suspension. Namely, an original tyre-wheel with additional unsprung mass, a suspension spring, an elastic top mount, damper bushings and a simplified wheel guiding mechanism. Each component was tested separately in order to identify its mechanical characteristics. The measured data serve as input parameters for a numerical simulation of the test bench behaviour by using a vibratory model with 3 degrees of freedom. Study on the simulation results and the measurements are needed for further development of the proposed test bench.

  5. Study of the response of Zircaloy cladding to thermal shock during water quenching after double sided steam oxidation at elevated temperatures

    International Nuclear Information System (INIS)

    Banerjee, Suparna; Sawarn, Tapan K.; Kumar, Sunil

    2015-01-01

    This study investigates the failure of embrittled Zircaloy-4 cladding used in the present generation of Indian pressurized heavy water reactors (IPHWRs) in a simulated LOCA condition and its correlation with the evolved stratified microstructure. Isothermal steam oxidation of Zircaloy-4 cladding at high temperatures (900-1200°C) with soaking periods in the range 60-900 seconds followed by water quenching was carried out. None of the pieces broke during quenching except for those heated at 1100, 1150 and 1200°C for longer durations. The combined oxide + oxygen stabilized α-Zr(O) layer thickness and the fraction of the load bearing phase of clad tube specimens were correlated with the %ECR values calculated using Baker-Just equation. Average oxygen concentration of the load bearing prior β-Zr phase corresponding to different oxidation conditions was calculated from the average microhardness values in Vickers scale using an empirical correlation developed by Leistikow. The results of these experiments are presented in this paper. Thermal shock sustainability of the clad was correlated with the %ECR, combined oxide+α-Zr(O) layer thickness, fraction of the prior β-Zr phase and its average oxygen concentration. The thermal shock boundary was observed to be 29% ECR, 0.29 mm combined thickness of ZrO_2+α-Zr(O), 0.16 mm of β-Zr thickness with an average β phase oxygen content of 0.69 wt%. (author)

  6. Thermal shock behavior of W-0.5 wt% Y{sub 2}O{sub 3} alloy prepared via a novel chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Mei-Ling [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Lai-Ma, E-mail: luolaima@126.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Lin, Jing-Shan [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zan, Xiang; Zhu, Xiao-Yong [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wu, Yu-Cheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China)

    2016-10-15

    A wet-chemical method combined with spark plasma sintering was used to prepare W-0.5 wt% Y{sub 2}O{sub 3} alloy. The W-0.5 wt% Y{sub 2}O{sub 3} precursor was reduced at 800 °C for 4 h under different hydrogen flow rates of 300, 400, 500, 600, and 700 ml/min. The reduced powder was analyzed by X-ray diffraction (XRD), laser particle size analyzer (LPSA), and scanning electron microscopy (SEM). An optimized process for reducing precursor was discussed. After sintering, the specimens were exposed to different laser beam irradiation energies (90, 120, 150, and 180 W) to simulate loads as expected for edge localized modes (ELMs). Top surface and cross-sectional morphology were observed by SEM, and the changes in hardness were evaluated. The changes in microstructural properties (i.e., Y{sub 2}O{sub 3}-particle distribution, crack propagation direction, depth of thermal shock effect, and grain size of the recrystallization region) after thermal shock were investigated.

  7. Thermal shock behavior of W-0.5 wt% Y_2O_3 alloy prepared via a novel chemical method

    International Nuclear Information System (INIS)

    Zhao, Mei-Ling; Luo, Lai-Ma; Lin, Jing-Shan; Zan, Xiang; Zhu, Xiao-Yong; Luo, Guang-Nan; Wu, Yu-Cheng

    2016-01-01

    A wet-chemical method combined with spark plasma sintering was used to prepare W-0.5 wt% Y_2O_3 alloy. The W-0.5 wt% Y_2O_3 precursor was reduced at 800 °C for 4 h under different hydrogen flow rates of 300, 400, 500, 600, and 700 ml/min. The reduced powder was analyzed by X-ray diffraction (XRD), laser particle size analyzer (LPSA), and scanning electron microscopy (SEM). An optimized process for reducing precursor was discussed. After sintering, the specimens were exposed to different laser beam irradiation energies (90, 120, 150, and 180 W) to simulate loads as expected for edge localized modes (ELMs). Top surface and cross-sectional morphology were observed by SEM, and the changes in hardness were evaluated. The changes in microstructural properties (i.e., Y_2O_3-particle distribution, crack propagation direction, depth of thermal shock effect, and grain size of the recrystallization region) after thermal shock were investigated.

  8. Pool fire upon a balsa-filled shock absorber

    International Nuclear Information System (INIS)

    Fry, C.J.

    1990-07-01

    When performing a safety assessment of a transport flask with balsa-filled shock absorbers it is important to know how the shock absorbers, which may have the outer skin punctured by an impact, will perform in a fire. A 30 minute pool test, which satisfied all the requirements of a thermal test under the IAEA regulations, was carried out upon a small, balsa-filled shock absorber. The outer steel shell was partly cut away exposing the wood to the fire and the air. The balsa wood prevented 90% of the heat from the fire from being transferred through the shock absorber, even though the balsa was only 133 mm thick. The maximum heat flux through to the inside of the shock absorber due to the burning of the balsa wood was relatively low, 2.8 kW/m 2 , and occurred 2 to 3 hours after the end of the pool fire. (author)

  9. Progressive damage during thermal shock cycling of D-gun sprayed thermal barrier coatings with hollow spherical ZrO{sub 2}-8Y{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Ke, P.L. [State Key Lab for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China) and School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom)]. E-mail: csun@imr.ac.cn; Wang, Q.M. [State Key Lab for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Gong, J. [State Key Lab for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Sun, C. [State Key Lab for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhou, Y.C. [State Key Lab for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2006-11-05

    Thermal shock cycling behaviors of D-gun sprayed TBCs with a hollow spherical ZrO{sub 2}-8Y{sub 2}O{sub 3} (HSP-YSZ) top coat and NiCrAlY bond coat on directionally solidified Ni-base superalloys DZ125 were investigated at high temperature (1100 deg. C) {r_reversible} room temperature (RT) repeatedly by water quenching. Scanning electron microscopy (SEM) was used to characterize the coating microstructure and failure morphology. The results showed that failure of the D-gun sprayed TBC starts with crack initiation along the splats boundary in the ceramic top coat and the non-alumina oxides. The cracks propagate and coalesce with the increasing thermal cycling. The extensive cracking of the rapidly formed non-alumina oxides, resulting from the depletion of aluminum in the bond coat, aids to delamination of the outer ceramic layer. The stress distributions in TGO layer at different thermal shock cycles was measured by luminescence spectroscopy to investigate the failure mechanism of TBC system.

  10. Energetic Materials Center Report--Small-Scale Safety and Thermal Testing Evaluation of Butyl Nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2013-04-26

    Butyl Nitrate (BN) was examined by Small-Scale Safety and Thermal (SSST) Testing techniques to determine its sensitivity to impact, friction, spark and thermal exposure simulating handling and storage conditions. Under the conditions tested, the BN exhibits thermal sensitivity above 150 °C, and does not exhibit sensitive to impact, friction or spark.

  11. An assessment of testing requirement impacts on nuclear thermal propulsion ground test facility design

    International Nuclear Information System (INIS)

    Shipers, L.R.; Ottinger, C.A.; Sanchez, L.C.

    1993-01-01

    Programs to develop solid core nuclear thermal propulsion (NTP) systems have been under way at the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA), and the Department of Energy (DOE). These programs have recognized the need for a new ground test facility to support development of NTP systems. However, the different military and civilian applications have led to different ground test facility requirements. The Department of Energy (DOE) in its role as landlord and operator of the proposed research reactor test facilities has initiated an effort to explore opportunities for a common ground test facility to meet both DoD and NASA needs. The baseline design and operating limits of the proposed DoD NTP ground test facility are described. The NASA ground test facility requirements are reviewed and their potential impact on the DoD facility baseline is discussed

  12. Thermal hydraulic tests for reactor safety system -Research on the improvement of nuclear safety-

    International Nuclear Information System (INIS)

    Chung, Moon Ki; Park, Chun Kyeong; Yang, Seon Kyu; Chung, Chang Hwan; Chun, Shee Yeong; Song, Cheol Hwa; Chun, Hyeong Gil; Chang, Seok Kyu; Chung, Heung Joon; Won, Soon Yeon; Cho, Yeong Ro; Kim, Bok Deuk; Min, Kyeong Ho

    1994-07-01

    The present research aims at the development of the thermal hydraulic verification test technology for the reactor safety system of the conventional and advanced nuclear power plant and the development of the advanced thermal hydraulic measuring techniques. (Author)

  13. Fast and thermal data testing of 233U critical assemblies

    International Nuclear Information System (INIS)

    Wright, R.Q.; Jordan, W.C.; Leal, L.C.

    1999-01-01

    Many sources have been used to obtain 233 U benchmark descriptions. Unfortunately, some of these are not reliable since a thorough and complete benchmark evaluation often has not been done. For 24 yr a principal source for 233 U benchmarks has been the Cross Section Evaluation Working Group (CSEWG) Benchmark Specifications. The CSEWG specifications included only two fast benchmarks and three thermal benchmarks. The thermal benchmarks were H 2 O-moderated thorium-oxide exponential lattices. Since the thorium-oxide lattices were exponential experiments, they have not been widely used. CSEWG has also used the 233 U Oak Ridge National Laboratory (ORNL) spheres for many years. One advantage of the CSEWG fast benchmarks, JEZEBEL-23 and FLATTOP-23, is that experiments were done for central-reaction-rate ratios. These reaction-rate ratios provide very valuable information to data testers and evaluators that would not otherwise be available. In recent years the International Handbook of Evaluated Criticality Safety Benchmark Experiments has, in general, been a very useful and reliable source. The Handbook does not include central-reaction-rate ratio experiments, however. A new set of 233 U benchmark experiments has been added to the most recent release of the Handbook, U233-SOL-THERM-004. These are paraffin-reflected cylinders of 233 U uranyl-nitrate solutions. Unfortunately, the estimated benchmark uncertainties are on the order of 0.9 to 1.0% in k eff . Benchmark testing has been done for some of these U233-SOL-THERM-004 experiments. The authors have also discovered that the benchmark specifications for the Thomas uranyl-nitrate experiments given in Ref. 5 are incorrect. One problem with the Ref. 5 specifications is that the excess acid was not included. As part of this work, the authors developed revised specifications that include an excess acid correlation based on information from the experimental logbook

  14. Mechanical Testing of Carbon Based Woven Thermal Protection Materials

    Science.gov (United States)

    Pham, John; Agrawal, Parul; Arnold, James O.; Peterson, Keith; Venkatapathy, Ethiraj

    2013-01-01

    Three Dimensional Woven thermal protection system (TPS) materials are one of the enabling technologies for mechanically deployable hypersonic decelerator systems. These materials have been shown capable of serving a dual purpose as TPS and as structural load bearing members during entry and descent operations. In order to ensure successful structural performance, it is important to characterize the mechanical properties of these materials prior to and post exposure to entry-like heating conditions. This research focuses on the changes in load bearing capacity of woven TPS materials after being subjected to arcjet simulations of entry heating. Preliminary testing of arcjet tested materials [1] has shown a mechanical degradation. However, their residual strength is significantly more than the requirements for a mission to Venus [2]. A systematic investigation at the macro and microstructural scales is reported here to explore the potential causes of this degradation. The effects of heating on the sizing (an epoxy resin coating used to reduce friction and wear during fiber handling) are discussed as one of the possible causes for the decrease in mechanical properties. This investigation also provides valuable guidelines for margin policies for future mechanically deployable entry systems.

  15. Thermal characteristic test for saturated temperature type capsule

    International Nuclear Information System (INIS)

    Niimi, Motoji; Someya, Hiroyuki; Kobayashi, Toshiki; Ohuchi, Mitsuo; Harayama, Yasuo

    1989-08-01

    The Japan Material Testing Reactor Project is developing a new type capsule so-called 'Saturated Temperature Capsule', as a part of irradiation technique improvement program. This type capsule, in which the water is supplied and boiled, bases on the conception of keeping the coolant at the saturated temperature and facilitating the temperature setting of specimens heated by gamma-ray in reactor. However, out-pile test was planned, because there were few usable data for design and operation of the capsule into which the coolant was injected. A out-pile apparatus, simulated the capsule with electric heaters, was fabricated and experiments were carried out, to obtain data concerning design and operation for the capsule into which the water was injected. As a structure of simulated capsule, a type of downward coolant supply was adopted. The downward coolant tube type injectes the water in the bottom of capsule by tube through the upper flange. Major objects of experiences were to grasp thermal features under operation and to provide performances of capsule control equipment. Experimental results proved that the temperature of water within the capsule was easily varied by controlling supply water flow rate, and that the control equipment was operated stably and safety. (author)

  16. Completed Gravity Probe B Undergoes Thermal Vacuum Testing

    Science.gov (United States)

    2000-01-01

    The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. In this photograph, the completed space vehicle is undergoing thermal vacuum environment testing. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation.)

  17. FFTF thermal-hydraulic testing results affecting piping and vessel component design in LMFBR's

    International Nuclear Information System (INIS)

    Stover, R.L.; Beaver, T.R.; Chang, S.C.

    1983-01-01

    The Fast Flux Test Facility completed four years of pre-operational testing in April 1982. This paper describes thermal-hydraulic testing results from this period which impact piping and vessel component design in LMFBRs. Data discussed are piping flow oscillations, piping thermal stratification and vessel upper plenum stratification. Results from testing verified that plant design limits were met

  18. Comments on Thermal Physical Properties Testing Methods of Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Jingchao Xie

    2013-01-01

    Full Text Available There is no standard testing method of the thermal physical properties of phase change materials (PCM. This paper has shown advancements in this field. Developments and achievements in thermal physical properties testing methods of PCM were commented, including differential scanning calorimetry, T-history measurement, the water bath method, and differential thermal analysis. Testing principles, advantages and disadvantages, and important points for attention of each method were discussed. A foundation for standardized testing methods for PCM was made.

  19. Assessment of the role of oxygen and mitochondria in heat shock induction of radiation and thermal resistance in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Morrison, D.P.

    1983-01-01

    In response to a heat shock, the yeast Saccharomyces cerevisiae undergoes a large increase in its resistance to heat and, by the induction of its recombinational DNA repair capacity, a corresponding increase in resistance to radiation. Yeast which lack mitochondrial DNA, mitochondria-controlled protein synthetic apparatus, aerobic respiration, and electron transport (rho 0 strain) were used to assess the role of O 2 , mitochondria, and oxidative processes controlled by mitochondria in the induction of these resistances. We have found that rho 0 yeast grown and heat shocked in either the presence or absence of O 2 are capable of developing both radiation and heat resistance. We conclude that neither the stress signal nor its cellular consequences of induced heat and radiation resistance are directly dependent on O 2 , mitochondrial DNA, or mitochondria-controlled protein synthetic or oxidative processes

  20. Fire testing and analysis of TRUPACT-I Thermal Test Article

    International Nuclear Information System (INIS)

    Romesberg, L.E.; Longenbaugh, R.S.; Joseph, B.J.

    1989-02-01

    This report documents the fabrication and thermal test of a full-scale prototype of the revised TRUPACT-I design. The fire test demonstrated that the response of the Test Article to a jet-fueled pool fire, subsequent to the impact and puncture tests, meets the impact, puncture, and thermal performance requirements of the regulations governing transport of radioactive materials. The Test Article was a replica of the front half (closure end) of the revised TRUPACT-I design. To simulate the cumulative effect of the regulatory hypothetical accident sequence, the Test Article included the structural damage found in TRUPACT-I, Unit 0 after regulatory drop and puncture testing. The Test Article was totally engulfed in a pool fire fueled by JP-4 jet fuel for 46 minutes. The maximum temperature reached at the inner door seals was 149/degree/C (300/degree/F) and the maximum temperature at the inner door filters was 171/degree/C (340/degree/F). Both temperatures are within the normal working range for these components. Post-test leak rate measurements of 0.0041 atm-cm 3 /s (ANSI standard air) between the innermost pair of door seals and 0.0046 atm-cm 3 /s (ANSI standard air) between the outermost pair of door seals verified that the performance of the silicone seals met the design requirements. Since no detectable leakage was measured to a sensitivity of 1.0E-7 atm-cm 3 /s for the filter installation seal or quick-connect valve seal post-test, the total leak rate for the containment system was less than the maximum allowable 0.01 atm-cm 3 /s (ANSI standard air). 10 refs., 52 figs., 5 tabs

  1. Results of thermal test of metallic molybdenum disk target and fast-acting valve testing

    Energy Technology Data Exchange (ETDEWEB)

    Virgo, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Jonah, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, G. F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-01

    This report describes the irradiation conditions for thermal testing of helium-cooled metallic disk targets that was conducted on March 9, 2016, at the Argonne National Laboratory electron linac. The four disks in this irradiation were pressed and sintered by Oak Ridge National Laboratory from molybdenum metal powder. Two of those disks were instrumented with thermocouples. Also reported are results of testing a fast-acting-valve system, which was designed to protect the accelerator in case of a target-window failure.

  2. Separate effects tests to determine the thermal dispersion in structured pebble beds in the PBMR HPTU test facility

    Energy Technology Data Exchange (ETDEWEB)

    Toit, C.G. du, E-mail: jat.dutoit@nwu.ac.za; Rousseau, P.G.; Kgame, T.L.

    2014-05-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTF test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effect of the porous structure on the fluid effective thermal conductivity due to the thermal dispersion. It also presents the methodology applied in the data analysis to derive the resultant values of the effective thermal conductivity and its associated uncertainty.

  3. Testing the structure of earthquake networks from multivariate time series of successive main shocks in Greece

    Science.gov (United States)

    Chorozoglou, D.; Kugiumtzis, D.; Papadimitriou, E.

    2018-06-01

    The seismic hazard assessment in the area of Greece is attempted by studying the earthquake network structure, such as small-world and random. In this network, a node represents a seismic zone in the study area and a connection between two nodes is given by the correlation of the seismic activity of two zones. To investigate the network structure, and particularly the small-world property, the earthquake correlation network is compared with randomized ones. Simulations on multivariate time series of different length and number of variables show that for the construction of randomized networks the method randomizing the time series performs better than methods randomizing directly the original network connections. Based on the appropriate randomization method, the network approach is applied to time series of earthquakes that occurred between main shocks in the territory of Greece spanning the period 1999-2015. The characterization of networks on sliding time windows revealed that small-world structure emerges in the last time interval, shortly before the main shock.

  4. Development of a test device to characterize thermal protective performance of fabrics against hot steam and thermal radiation

    International Nuclear Information System (INIS)

    Su, Yun; Li, Jun

    2016-01-01

    Steam burns severely threaten the life of firefighters in the course of their fire-ground activities. The aim of this paper was to characterize thermal protective performance of flame-retardant fabrics exposed to hot steam and low-level thermal radiation. An improved testing apparatus based on ASTM F2731-11 was developed in order to simulate the routine fire-ground conditions by controlling steam pressure, flow rate and temperature of steam box. The thermal protective performance of single-layer and multi-layer fabric system with/without an air gap was studied based on the calibrated tester. It was indicated that the new testing apparatus effectively evaluated thermal properties of fabric in hot steam and thermal radiation. Hot steam significantly exacerbated the skin burn injuries while the condensed water on the skin’s surface contributed to cool down the skin tissues during the cooling. Also, the absorbed thermal energy during the exposure and the cooling was mainly determined by the fabric’s configuration, the air gap size, the exposure time and the existence of hot steam. The research provides a effective method to characterize the thermal protection of fabric in complex conditions, which will help in optimization of thermal protection performance of clothing and reduction of steam burn. (paper)

  5. Transient and steady-state flows in shock tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, K. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Goettingen (Germany); Jacobs, P.A. [Queensland Univ., Brisbane (Australia). Dept. of Mechanical Engineering; Thomas, A.; McIntyre, T.J. [Queensland Univ., Brisbane, QLD. (Australia). Dept. of Physics

    1999-12-01

    Due to the difficulty of measuring all necessary flow quantities in the nozzle reservoir and the test section of high enthalpy shock tunnels, indirect computational methods are necessary to estimate the required flow parameters. In addition to steady state flow computations of the nozzle flow and the flow past wind tunnel models it is necessary to investigate the transient flow in the facility in order to achieve a better understanding of its performance. These transient effects include the nozzle starting flow, the interaction of the shock tube boundary layers and the reflected shock, thermal losses in the shock reflection region and the developing boundary layers in the expanding section of the nozzle. Additionally, the nonequilibrium chemical and thermal relaxation models which are used to compute high enthalpy flows have to be validated with appropriate experimental data. (orig.)

  6. Transient and steady-state flows in shock tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, K. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Goettingen (Germany)); Jacobs, P.A. (Queensland Univ., Brisbane (Australia). Dept. of Mechanical Engineering); Thomas, A.; McIntyre, T.J. (Queensland Univ., Brisbane, QLD. (Australia). Dept. of Physics)

    1999-01-01

    Due to the difficulty of measuring all necessary flow quantities in the nozzle reservoir and the test section of high enthalpy shock tunnels, indirect computational methods are necessary to estimate the required flow parameters. In addition to steady state flow computations of the nozzle flow and the flow past wind tunnel models it is necessary to investigate the transient flow in the facility in order to achieve a better understanding of its performance. These transient effects include the nozzle starting flow, the interaction of the shock tube boundary layers and the reflected shock, thermal losses in the shock reflection region and the developing boundary layers in the expanding section of the nozzle. Additionally, the nonequilibrium chemical and thermal relaxation models which are used to compute high enthalpy flows have to be validated with appropriate experimental data. (orig.)

  7. Expression of heat shock proteins (HSPs) in Aedes aegypti (L) and Aedes albopictus (Skuse) (Diptera: Culicidae) larvae in response to thermal stress.

    Science.gov (United States)

    Sivan, Arun; Shriram, Ananganallur Nagarajan; Muruganandam, Nagarajan; Thamizhmani, Ramanathan

    2017-03-01

    Climatic changes are responsible, to a certain extent for the occurrence and spread of arboviral pathogens world over. Temperature is one of the important abiotic factors influencing the physiological processes of mosquitoes. Several genes of heat shock protein (HSP) families are known to be expressed in mosquitoes, which aid in overcoming stress induced by elevated temperature. In order to understand expression of HSP family genes in the Andaman population of Aedes aegypti and Aedes albopictus, we used quantitative real-time polymerase chain reaction (qPCR) to examine expression levels of HSPs in response to thermal stress under laboratory and in actual field conditions. HSP genes AeaHsp26, AeaHsp83 and AeaHsc70 were examined by comparing relative transcript expression levels at 31°C, 33°C, 34°C, 37°C and 39°C respectively. Enhanced up-regulation of HSPs was evident in third instar larvae of Ae. aegypti with rise in water temperatures (31°C, 33°C, 34°C) in the containers in the nature and thermally stressed (37°C and 39°C) in laboratory conditions. In Ae. albopictus up-regulation of HSPs was observed in field conditions at 34°C only and when thermally treated at 37°C, while down regulation was evident in larvae subjected to thermal stress in laboratory at 39°C. Data on expression levels revealed that larvae of Ae. aegypti was tolerant to thermal stress, while Ae. albopictus larvae was sensitive to heat shock treatment. Statistical analysis indicated that AeaHsp83 genes were significantly up-regulated in Ae. aegypti larvae after 360min exposure to high temperature (39°C). The difference in expression levels of AeaHsp26, AeaHsc70 and AeaHsp83 genes in Ae. albopictus larvae was statistically significant between different exposure temperatures. All of these genes were significantly up-regulated at 37°C. These results indicate that AeaHsp26, AeaHsc70 and AeaHsp83 are important markers of stress and perhaps function as proteins conferring protection and

  8. Response of heat shock protein genes of the oriental fruit moth under diapause and thermal stress reveals multiple patterns dependent on the nature of stress exposure.

    Science.gov (United States)

    Zhang, Bo; Peng, Yu; Zheng, Jincheng; Liang, Lina; Hoffmann, Ary A; Ma, Chun-Sen

    2016-07-01

    Heat shock protein gene (Hsp) families are thought to be important in thermal adaptation, but their expression patterns under various thermal stresses have still been poorly characterized outside of model systems. We have therefore characterized Hsp genes and their stress responses in the oriental fruit moth (OFM), Grapholita molesta, a widespread global orchard pest, and compared patterns of expression in this species to that of other insects. Genes from four Hsp families showed variable expression levels among tissues and developmental stages. Members of the Hsp40, 70, and 90 families were highly expressed under short exposures to heat and cold. Expression of Hsp40, 70, and Hsc70 family members increased in OFM undergoing diapause, while Hsp90 was downregulated. We found that there was strong sequence conservation of members of large Hsp families (Hsp40, Hsp60, Hsp70, Hsc70) across taxa, but this was not always matched by conservation of expression patterns. When the large Hsps as well as small Hsps from OFM were compared under acute and ramping heat stress, two groups of sHsps expression patterns were apparent, depending on whether expression increased or decreased immediately after stress exposure. These results highlight potential differences in conservation of function as opposed to sequence in this gene family and also point to Hsp genes potentially useful as bioindicators of diapause and thermal stress in OFM.

  9. DHS small-scale safety and thermal testing of improvised explosives-comparison of testing performance

    International Nuclear Information System (INIS)

    Reynolds, J G; Hsu, P C; Sandstrom, M M; Brown, G W; Warner, K F; Phillips, J J; Shelley, T J; Reyes, J A

    2014-01-01

    One of the first steps in establishing safe handling procedures for explosives is small-scale safety and thermal (SSST) testing. To better understand the response of improvised materials or homemade explosives (HMEs) to SSST testing, 16 HME materials were compared to three standard military explosives in a proficiency-type round robin study among five laboratories-two DoD and three DOE-sponsored by DHS. The testing matrix has been designed to address problems encountered with improvised materials-powder mixtures, liquid suspensions, partially wetted solids, immiscible liquids, and reactive materials. More than 30 issues have been identified that indicate standard test methods may require modification when applied to HMEs to derive accurate sensitivity assessments needed for developing safe handling and storage practices. This paper presents a generalized comparison of the results among the testing participants, comparison of friction results from BAM (German Bundesanstalt für Materi-alprüfung) and ABL (Allegany Ballistics Laboratory) designed testing equipment, and an overview of the statistical results from the RDX (1,3,5-Trinitroperhydro-1,3,5-triazine) standard tested throughout the proficiency test.

  10. Testing of Local Velocity Transducer Used at Sodium Thermal Hydraulic Test Facilities

    International Nuclear Information System (INIS)

    Kim, Tae Joon; Eoh, Jae Hyuk; Hwang, In Koo; Jeong, Ji Young; Kim, Jong Man; Lee, Yong Bum; Kim, Yeong Il

    2012-01-01

    KAERI (Korea Atomic Energy Research Institute) will perform a test for a thermal hydraulic simulation with STELLA-1 for a Component Performance Test Sodium Loop in the year 2012, and subsequently it will construct for STELLA-2 for a Sodium Thermalhydraulic Experimental Facility in the year 2016. The STELLA-2 consists of a scaled reactor vessel with a core of electric heaters, four IHXs, two PHTS pumps, two DHXs, and two AHXs. In STELLA-2, several kinds of flow measurements exists. In this paper, the local velocity transducer as a prototype tested in IPPE (in Russia), was manufactured as a prototype by a shop in KAERI. This local velocity transducer will be used to measure the flow rate in a pool

  11. Validation of the Large Interface Method of NEPTUNE{sub C}FD 1.0.8 for Pressurized Thermal Shock (PTS) applications

    Energy Technology Data Exchange (ETDEWEB)

    Coste, P., E-mail: pierre.coste@cea.fr [CEA, DEN, DER/SSTH, F-38054 Grenoble (France); Lavieville, J. [Electricite de France, Chatou (France); Pouvreau, J. [CEA, DEN, DER/SSTH, F-38054 Grenoble (France); Baudry, C.; Guingo, M.; Douce, A. [Electricite de France, Chatou (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The two-phase Pressurized Thermal Shock (PTS) is a key thermohydraulics issue for PWR safety. Black-Right-Pointing-Pointer The dynamic and condensation models are firstly validated separately. Black-Right-Pointing-Pointer Then the global validation is done with the COSI experiment. Black-Right-Pointing-Pointer All the calculations performed with the same set of models both in the Large Interface Method and in the k-{epsilon} approach for turbulence substantiate the application of the tool to PTS. - Abstract: NEPTUNE{sub C}FD is a code based on a 3D transient Eulerian two-fluid model. One of the main application targets is the two-phase Pressurized Thermal Shock (PTS), which is related to PWR Reactor Pressure Vessel (RPV) lifetime safety studies, when sub-cooled water from Emergency Core Cooling (ECC) system is injected into the possibly uncovered cold leg and penetrates into the RPV downcomer. Five experiments were selected for the validation, a selection reviewed by a panel of European experts. The dynamic models are validated with a co-current smooth and wavy air-water stratified flow in a rectangular channel with detailed measurements of turbulence and velocities. The condensation models are validated with a co-current smooth and wavy steam-water stratified flow in a rectangular channel with measurements of the steam flow rates. The dynamic models are validated in the situation of a jet impinging a pool free surface with two experiments dealing with a water jet impingement on a water pool free surface in air environment. Finally, all the models involved in the reactor conditions are validated with the COSI experiment. The calculations are done with the same set of Large Interface Method models and a RANS (k-{epsilon}) approach for turbulence. They substantiate the application of the tool to PTS studies.

  12. A new plastic correction for the stress intensity factor of an under-clad defect in a PWR vessel subjected to a pressurised thermal shock

    International Nuclear Information System (INIS)

    Marie, S.; Nedelec, M.

    2007-01-01

    For the assessment of an under-clad defect in a vessel subjected to a cold pressurised thermal shock, plasticity is considered through the amplification β of the elastic stress intensity factor K I in the ferritic part of the vessel. An important effort has been made recently by CEA to improve the analytical tools in the frame of R and D activities funded by IRSN. The current solution in the French RSE-M code has been developed from fitted F.E. calculation results. A more physical solution is proposed in this paper. This takes into account two phenomena: the amplification of the elastic K I due to plasticity in the cladding and a plastic zone size correction in the ferritic part. The first correction has been established by representing the cladding plasticity by an imposed displacement on the crack faces at the interface between the cladding and the ferritic vessel. The corresponding elastic stress intensity factor is determined from the elastic plane strain asymptotic solution for the opening displacement. Plasticity in the ferritic steel is considered through a classical plastic zone size correction. The application of the solution to axisymmetric defects is first checked. The case of semi-elliptical defects is also investigated. For the correction determined at the interface between the cladding and the ferritic vessel, an amplification of the correction proposed for the deepest point is determined from a fitting of the 3D F.E. calculation results. It is also shown that the proposition of RSE-M, which consists in applying the same β correction at the deepest point and the interface point is not suitable. The applicability to a thermal shock, eventually combined with an internal pressure has been verified. For the deepest point, the proposed correction leads to similar results to the RSE-M method, but presents an extended domain of validity (no limits on the crack length are imposed)

  13. Boundary element analysis of stress due to thermal shock loading or reactor pressure vessel nozzle; Napetostna analiza pri nestacionarni termicni obremenitvi cevnega prikljucka reaktorske tlacne posode z metodo robnih elementov

    Energy Technology Data Exchange (ETDEWEB)

    Kramberger, J; Potrc, I [Tehniska fakulteta, Maribor (Yugoslavia)

    1989-07-01

    Apart from being exposed to the primary loading of internal pressure and steady temperature field, the reactor pressure vessel is also subject to various thermal transients (thermal shocks). Theoretical and experimental stress analyses show that severe material stresses occur in the nozzle area of the pressure vessel which may lead to defects (cracks). It has been our aim to evaluate these stresses by the use of the Boundary Element method. (author)

  14. Influences of Traction Load Shock on Artificial Partial Discharge Faults within Traction Transformer—Experimental Test for Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Shuaibing Li

    2017-10-01

    Full Text Available Partial discharge (PD measurement and its pattern recognition are vital to fault diagnosis of transformers, especially to those traction substation transformers undergoing repetitive traction load shocks. This paper presents the primary factors induced by traction load shocks including high total harmonics distortion (THD, transient voltage impulse and high-temperature rise, and their effects on the feature parameters of PD. Experimental tests are conducted on six artificial PD models with these factors introduced one by one. Results reveal that the maximum PD quantity and the PD repetitive rate are favorable to be enlarged when the oil temperature exceeds 80 °C or the THD is higher than 16% with certain orders of harmonic. The decline in PD inception voltage can mainly be attributed to the transient voltage impulse. The variation in central frequency of the fast Fourier transformation (FFT spectra transformed from ultra-high frequency signals can mainly be attributed to high THD, especially when it exceeds 20%. The temperature rise has no significant influence on the FFT spectra; the transient voltage impulse, however, can result in a central frequency shift of the floating particle discharge. With the rapid development of high-speed railways, the study presented in this paper will be helpful for field PD detection and recognition of traction substation transformers in the future.

  15. Numerical prediction of shock induced oscillations over a 2D airfoil: Influence of turbulence modelling and test section walls

    Energy Technology Data Exchange (ETDEWEB)

    Thiery, Mylene [Aerodynamics and Energetics Modelling Department, Turbulence Modelling and Prediction Unit, ONERA Toulouse, 2 avenue Edouard Belin, 31055 Toulouse Cedex 4 (France); Coustols, Eric [Aerodynamics and Energetics Modelling Department, Turbulence Modelling and Prediction Unit, ONERA Toulouse, 2 avenue Edouard Belin, 31055 Toulouse Cedex 4 (France)]. E-mail: Eric.Coustols@onera.fr

    2006-08-15

    The present study deals with recent numerical results from on-going research conducted at ONERA/DMAE regarding the prediction of transonic flows, for which shock wave/boundary layer interaction is important. When this interaction is strong enough (M {>=} 1.3), shock induced oscillations (SIO) appear at the suction side of the airfoil and lead to the formation of unsteady separated areas. The main issue is then to perform unsteady computations applying appropriate turbulence modelling and relevant boundary conditions with respect to the test case. Computations were performed with the ONERA elsA software and the URANS-type approach, closure relationships being achieved from transport-equation models. Applications are provided for the OAT15A airfoil data base, well documented for unsteady CFD validation (mean and r.m.s. pressure, phase-averaged LDA data, ...). In this paper, the capabilities of turbulence models are evaluated with two 2D URANS strategies, under free-stream or confined conditions. The latter takes into account the adaptive upper and lower wind-tunnel walls. A complete 3D URANS simulation was then performed to demonstrate the real impact of all lateral wind-tunnel walls on such a flow.

  16. Numerical prediction of shock induced oscillations over a 2D airfoil: Influence of turbulence modelling and test section walls

    International Nuclear Information System (INIS)

    Thiery, Mylene; Coustols, Eric

    2006-01-01

    The present study deals with recent numerical results from on-going research conducted at ONERA/DMAE regarding the prediction of transonic flows, for which shock wave/boundary layer interaction is important. When this interaction is strong enough (M ≥ 1.3), shock induced oscillations (SIO) appear at the suction side of the airfoil and lead to the formation of unsteady separated areas. The main issue is then to perform unsteady computations applying appropriate turbulence modelling and relevant boundary conditions with respect to the test case. Computations were performed with the ONERA elsA software and the URANS-type approach, closure relationships being achieved from transport-equation models. Applications are provided for the OAT15A airfoil data base, well documented for unsteady CFD validation (mean and r.m.s. pressure, phase-averaged LDA data, ...). In this paper, the capabilities of turbulence models are evaluated with two 2D URANS strategies, under free-stream or confined conditions. The latter takes into account the adaptive upper and lower wind-tunnel walls. A complete 3D URANS simulation was then performed to demonstrate the real impact of all lateral wind-tunnel walls on such a flow

  17. Comparison of theoretical estimates and experimental measurements of fatigue crack growth under severe thermal shock conditions (part one - experimental observations)

    International Nuclear Information System (INIS)

    Marsh, D.; Green, D.; Parker, R.

    1984-01-01

    This paper reports the results of an experiment in which a severe thermal cycle comprising of alternate upshocks and downshocks has been applied to an axisymmetric feature with an internal, partial penetration weld and crevice. The direction of cracking and crack growth rate were observed experimentally and detailed records made of the thermal cycle. A second part to the paper, reported separately, compares a linear elastic fracture mechanics assessment of the cracking to the experimental observations

  18. Thermal design and test verification of GALAXY evolution explorer (GALEX)

    Science.gov (United States)

    Wu, P. S.; Lee, S. -C.

    2002-01-01

    This paper describes the thermal control design of GALEX, an ultraviolet telescope that investigates the UV properties of local galaxies, history of star formation, and global causes of star formation and evolution.

  19. Test of thermal shields for early warning station detectors

    DEFF Research Database (Denmark)

    Petersen, Jesper

    1997-01-01

    The properties of thermal shields around NaI crystal scintillators for early warning stations have been checked in order to assure that external temperature variations cannot influence the stability of the measurements....

  20. Elastic response of thermal spray deposits under indentation tests

    International Nuclear Information System (INIS)

    Leigh, S.H.; Lin, C.K.; Berndt, C.C.

    1997-01-01

    The elastic response behavior of thermal spray deposits at Knoop indentations has been investigated using indentation techniques. The ration of hardness to elastic modulus, which is an important prerequisite for the evaluation of indentation fracture toughness, is determined by measuring the elastic recovery of the in-surface dimensions of Knoop indentations. The elastic moduli of thermal spray deposits are in the range of 12%--78% of the comparable bulk materials and reveal the anisotropic behavior of thermal spray deposits. A variety of thermal spray deposits has been examined, including Al 2 O 3 , yttria-stabilized ZrO 2 (YSZ), and NiAl. Statistical tools have been used to evaluate the error estimates of the data