Energy Technology Data Exchange (ETDEWEB)

A 25m wind turbine blade was tested to failure when subjected to a flapwise load. With the test setup, it was possible to test the blade to failure at three diffe-rent locations. The objective of these tests is to learn about how a wind turbine blade fails when exposed to a large flapwise load and how failures propagate. The report shows also results from ultra sonic scan of the surface of the blade and it is seen to be very useful for the detection of defects, especially in the layer between the skin laminate and the load carrying main spar. Acoustic emission was successfully used as sensor for the detection of damages in the blade during the test. The report contains measurements of the total deflection of the blade, the local deflection of the skin and the ...

Energy Technology Data Exchange (ETDEWEB)

This document presented the results of a full-scale pile load tests conducted on helix pile foundations supporting power transmission towers in northern Manitoba. The site conditions were described along with pile installation and the performance of the foundations. The pile load tests were carried out in 2 different soil conditions, notably soft to firm clays and stiff high plastic clays with silt varves. The performance of the helix pile foundations were examined under axial compressive and axial tension (uplift) loading conditions. The results of the compressive load tests were presented in the form of load settlement curves while the results of the uplift load tests were presented in the form of load displacement curves. Both types of ...

Energy Technology Data Exchange (ETDEWEB)

Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were filled with steam. Two testing temperatures were employed, each with its own steam condition. These temperatures and steam conditions were 650/sup 0/F with saturated steam (5% liquid, 95% vapor) and 1200/sup 0/F with superheated steam at 2200 psi. The low-cycle fatigue tests were carried out at both 650/sup 0/F and 1200/sup 0/F by cycling the strain between equal tensile and compressive magnitudes until specimen failure or until it was no longer practical to continue the test. The creep-fatigue tests were carried out to failure by cycling the strain in the same fashion as in the low-cycle fatigue tests but with holds imposed at either the peak tensile strain or the peak compressive strain or at both peak ...

Energy Technology Data Exchange (ETDEWEB)

This book presents the proceedings of a conference dedicated to the design and operation of pipework in all its aspects, involving both metallic and non-metallic materials. Topics considered include a study of single mitre pipe bends using the finite element method; tests to failure of GRP pipe bends under in-plane flexural loading; finite element stress analysis of an equal diameter branch pipe intersection subjected to internal pressure and in-plane moment loadings; finite element stress analysis of extruded outlet tee junctions; design of pipework on the British PWR; a review of advanced remanent life methods for pipes operating in the creep range; pipe whip analysis and design; damping values for piping systems; pipework snubbers based on electro-rheological fluids; and the seismic design of piping systems in the flexible range.

Energy Technology Data Exchange (ETDEWEB)

Sandia National Laboratories contracted with Rockwell International Science Center to perform a series of narrowband, pseudo-random cyclic fatigue tests on sections of 6063-T651 aluminum, Darrius-type, vertical axis wind turbine (VAWT) airfoils. We designed and constructed a load member that was mounted within the frame of a rigid 200-kip servohydraulic, closed-loop test system to hold the VAWT section and permit cantilever bending along the shear centerline of the beam. A computer program was developed to synthesize a narrow band, pseudo-random load history with fixed root mean square (RMS) stress levels at a given bandwidth and central frequency. Six specimens each of two different weld configurations at the flange mounting plate were tested at several RMS stress levels with failure defined as visual observation of a 3-inch-long crack in the VAWT. In order to ...

Science.gov (United States)

Ultimate Compressive Strength = 3000.0 psi. 3.0 Failure Criteria. The structural criteria used to evaluate the combustor components was chosen ...

Energy Technology Data Exchange (ETDEWEB)

Stress corrosion cracking tests in constant extension rate tensile (CERT) and constant load tensile (CLT) tests were conducted on Ni-xCr- 9Fe-yC in Ar, water, and a LiOH-boric acid solution. Cr and C improve the resistance of Ni-base alloys to IG cracking in both Ar and water at 360C. Since creep plays a role in IG cracking, one possible explanation for the role of the environment involves its effect on the creep. Experiments were conducted on the role of C in the deformation behavior and failure mode of Ni-16Cr-9Fe. Constant load experiments were conducted on Ni-16Cr-9Fe to determine if the CLT test is more aggressive than CERT. The electron backscattering technique in a SEM is being developed in order to extend the IG cracking studies to grain sizes typical of commercial alloys, 20-30 microns.

Energy Technology Data Exchange (ETDEWEB)

The Wendelstein 7-X (W7-X) modular stellarator is under construction at the Max-Planck-Institut fuer Plasmaphysik in Greifswald, Germany. The W7-X magnet system contains 70 coils made up from helium cooled superconducting cables in aluminium alloy (EN AW-6063) jackets. Several hundred connections of the jacket to the cable joints are made by aluminium-to-aluminium welds. Due to geometrical and thermal boundary conditions these welds cannot be accomplished free from defects. Microscopic analyses of the welds show that a variety of small flaws such as cracks and pores develop during welding. The welds have thus to be dimensioned accordingly, and appropriate weld qualification, investigation and testing has to be done in order not to jeopardise the structural integrity and leak tightness. The weld is mechanically loaded during cool-down due to the difference in thermal contractions between the GRP insulation and the aluminium, and during operation ...

Energy Technology Data Exchange (ETDEWEB)

Power system components, especially components failure, can significantly affect the reliability of a power system. Data about failure rate in electrical products were obtained from products life testing and analyzed in order to predict reliability. The distribution curve fitting method was used to estimate failure probability. Ten relays of different life times have been used to illustrate the validity of this analytical technique. 3 refs., 3 tabs.

Science.gov (United States)

Polymer matrix composites are presently used in many fields due to their excellent mechanical properties such as high specific strength and stiffness. However, not much is known of these composites' response to impact loading, which usually occurs at strain rates much higher than the strain rates used to measure the quasi-static mechanical properties of materials. The use of static properties in the study of structures that undergo dynamic loading can produce excessive design weight or cause unexplained and untimely failure. The studies included in this dissertation provide the results of Split Hopkinson Pressure Bar experiments to determine the ultimate compressive strength and strain of composites at high strain rates. Most researchers are using specimens with different dimensions and geometry. For this reason, it is difficult to compare results of tests done by different people. Herein, the Split ...

British Library Electronic Table of Contents (United Kingdom)

Glass fiber-reinforced polymer (GFRP) reinforcing bars were used recently as main reinforcement for concrete structures. The noncorrodible GFRP material exhibits linear-elastic stress-strain characteristics up to failure with relatively low modulus of elasticity compared to steel. This raises concerns on GFRP performance in structures where energy dissipation, through plastic behavior, is required. The objective of this research project is to assess the seismic behavior of concrete beam-column joints reinforced with GFRP bars and stirrups. Two full-scale exterior T-shaped beam-column joint prototypes are constructed and tested under simulated seismic load conditions. One prototype is totally reinforced with GFRP bars and stirrups, while the other one is reinforced with steel. The experimen...

Energy Technology Data Exchange (ETDEWEB)

A micro-mechanistic understanding of bone fracture that encompasses how cracks interact with the underlying microstructure and defines their local failure mode is lacking, despite extensive research on the response of bone to a variety of factors like aging, loading, and/or disease. Micro-mechanical models for fracture incorporating such local failure criteria have been widely developed for metallic and ceramic materials systems; however, few such deliberations have been undertaken for the fracture of bone. In fact, although the fracture event in mineralized tissues such as bone is commonly believed to be locally strain controlled, until recently there has been little experimental evidence to support this widely held belief. In the present study, a series of in vitro experiments involving a double-notch bend test geometry are performed in order to shed further light on the nature of the local cracking ...

Science.gov (United States)

S>Hydrogen-induced delayed failure in an alpha-beta titanium alloy (4Al-- 4Mn) was sensitive to microstructure. A quenched structure was less susceptible to delayed failure than aged or annealed structures. The tendency for delayed failure was magnified in all structures by an increase in hydrogen content or an increase in strength level. Hydrogen-induced delayed failure occurred by a process of crack initiation and controlled crack growth. Delayed failures resulting from creep were also encountered. Plastic strain resulting from creep tended to retard crack initiation. Changes occurring in material under static load prior to formation of cracks were reversible, as long as no appreciable plastic strain occurred, indicating stress-induced diffusion of hydrogen. Hydrogen-induced delayed failure disappeared at both ...

Energy Technology Data Exchange (ETDEWEB)

Coilguns have demonstrated their capability to launch projectiles to 1 km/s, and there is interest in their application for long-range precision strike weapons. However, the incorporation of cooling systems for repetitive operation will impact the mechanical design and response of the future coils. To assess the impact of such changes, an evaluation of the ruggedness and reliability of the existing 50 mm bore coil designed in 1993 was made by repeatedly testing at stress levels associated with operation in a coilgun. A two-coil testbed has been built with a static projectile where each coil is energized by its own capacitor bank. Simulation models of the applied forces generated in this testbed have been created with the SLINGSHOT circuit code to obtain loads equivalent to the worst-case anticipated in a 50 mm coilgun that could launch a 236 g projectile to 2 km/s. Bench measurements of the seven remaining coils built in 1993 have been used to ...

Energy Technology Data Exchange (ETDEWEB)

A micro-mechanistic understanding of bone fracture thatencompasses how cracks interact with the underlying microstructure anddefines their local failure mode is lacking, despite extensive research nthe response of bone to a variety of factors like aging, loading, and/ordisease.

Energy Technology Data Exchange (ETDEWEB)

The paper presents results of studies on the effect of heat treatment on strength and pattern of 40Kh steel impact failure. Loading levels corresponding to macroscopic spalling microdamage initiation in the material are determined for three initial states. Metallographic study on the spalling failure pattern for 40Kh steel in different initial states and data on microhardness measurement are presented.

Energy Technology Data Exchange (ETDEWEB)

Diamond-like carbon thin films for tribological applications were deposited by d.c.-magnetron sputtering of a graphite target in a pure argon atmosphere or in a reactive hydrogen or methane atmosphere at pressures between 0.1 and 1 Pa in a graded constitution to improve adhesion and reduce residual stress. The temperature of the metallic, carbon- and ceramic-like substrates was below 100 C. The mechanical, thermal, electronic and optical properties of the carbon thin films show a significant dependence on the ion energy. Below 220 eV, strongly adherent black conductive films with hardness values up to 2000 HV0.05 were obtained. Hard and superhard diamond-like carbon thin films were deposited in an energy range between 220 and 370 eV with hardness values up to 4000 HV0.05. They are insulating, optically transparent and show a high degree of hardness combined with high compressive stress in the order of 4 GPa as well as a low adhesion, which means that the critical ...

Energy Technology Data Exchange (ETDEWEB)

This probabilistic analysis of WIPP TRUDOCK crane failure is based on two sources of failure data. The source for operator errors is the report by Swain and Guttman, NUREG/CR-1278-F, August 1983. The source for crane cable hook breaks was initially made by WIPP/WID-96- 2196, Rev. O by using relatively old (1970s) U.S. Navy data (NUREG-0612). However, a helpful analysis by R.K. Deremer of PLG guided the authors to values that were more realistic and more conservative, with the recommendation that the crane cable/hook failure rate should be 2.5 x 10-6 per demand. This value was adopted and used. Based on these choices a mean failure rate of 9.70 x 10-3(1/yr) was calculated. However, a mean rate by itself does not reveal the level of confidence to be associated with this number. Guidance to making confidence calculations came from the report by Swain and Guttman, who stated that ...

UK PubMed Central (United Kingdom)

AimsThe prevalence and importance of liver function test (LFT) abnormalities in a large contemporary cohort of heart failure patients have not been systematically evaluated.Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This document describes a simple and general way to generate House Simulation Protocol (HSP)-consistent internal sensible and latent loads in unoccupied homes. It is newly updated based on recent experience, and provides instructions on how to calculate and set up the operational profiles in unoccupied homes. The document is split into two sections: how to calculate the internal load magnitude and schedule, and then what tools and methods should be used to generate those internal loads to achieve research goals.

Energy Technology Data Exchange (ETDEWEB)

Most of previous study for creep rupture of RPV lower head under severe accident condition, have been focused on global failure of RPV lower head. In contract, the local failure of the RPV nozzle region has not been studied in detail. The existence and features of nozzle failure in LAVA-ICI specimen of KAERI and LHF-4 specimen of Sandia National Lab., are observed. It is confirmed that the nozzle failure of LHF-4 specimen is due to the hoop stress in the RPV. The tensile tests in various temperatures and the creep rupture tests in various temperatures and stresses, are accomplished. The finite element analysis for LAVA-ICI experiment was confirmed, and the stress and deformation analysis results are used in LAVA-ICI experiment. 17 refs., 34 figs., 3 tabs. (Author)

International Nuclear Information System (INIS)

The TS-1 and TS-2 TREAT transient experiments subjected a low burnup (2 MWd/kg) and a medium burnup (58 MWd/kg), respectively, FFTF irradiated fuel pin to unprotected 5 cents/s overpower transient conditions. The fuel pin failure response was similar in the two tests, which demonstrated a large margin to failure (P/P_0 > 3) and a favorable upper level failure location. Thus, for these transient conditions, burnup effects on transient performance appeared to be minimal in the range tested. Pin disruption in the medium burnup TS-2 test was more severe due to the higher fission gas pressurization, but failure occurred at only a 5% lower power level than for the low burnup TS-1 fuel pin. Both tests exhibited axial extrusion of molten fuel to the region above the fuel column several seconds before pin ...

International Nuclear Information System (INIS)

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating variables are stored in a PC for off line ...

Energy Technology Data Exchange (ETDEWEB)

Two accelerated aging test procedures are proposed for use on solid dielectric extruded distribution cables under wet conditions. One test method is a fixed time duration test in which the degree of cable specimen aging is assessed in terms of breakdown tests, while the other test method is a time to breakdown test in which the cable specimens are voltage stressed until failure ensues.

Science.gov (United States)

Oak Ridge National Laboratory (ORNL) has for over ten years provided materials testing and failure analysis services to various coal conversion and utilization facilities in the United States. ORNL was involved in these types of activities at all four of the major coal liquefaction pilot plants. This paper presents a summary of activities at Wilsonville over the past two and one-half years. Some details of these activities are discussed below. Failure analysis of elastomers, stainless steels, and alloys is discussed. 6 refs., 9 figs., 13 tabs.

International Nuclear Information System (INIS)

The TS-1 and TS-2 Transient Reactor Test Facility (TREAT) experiments were conducted on irradiated Fast Flux Test Facility (FFTF) fuel pins to characterize their failure behavior when subjected to hypothetical 5%/s transient overpower conditions. The TS-1 test employed a near-fresh (2 MWd/kg) fuel pin, while the TS-2 test used a medium-burnup (58 MWd/kg) fuel pin. Transient conditions were closely matched between the two experiments to provide a direct comparison of burnup effects on the failure response.

Science.gov (United States)

Analytical models for predicting the deformation and failure of composite sandwich panels subjected to blast and projectile impact loading are presented in this paper. The analytical predictions of the transient deformations and damage initiation in the composite sandwich panels were compared with finite element solutions using ABAQUS Explicit. For the blast model, the predicted transient deformation of the sandwich panel was within 7%of FEA results, while the predicted damage initiation using Hashin's composite failure criteria was about 15%higher than FEA results in most cases. For the high velocity impact model, the predicted transient deformations were within 20%of FEA results.

Energy Technology Data Exchange (ETDEWEB)

Strain-controlled fatigue experiments under simultaneous irradiation have been performed to investigate the specific loadings of structural materials in next-step fusion devices. All irradiations were done on specimens made of the tempered ferritic/martensitic Cr steel MANET-I at 420 C using a 104 MeV [alpha]-particle beam. Continuous push-pull cycling (R=-1) has been applied with total strain ranges [Delta][epsilon][sub t] between 0.5 and 1.0%. Under in-beam conditions at e.g. [Delta][epsilon][sub t]= 0.5% a number of cycles to failure of N[sub f]=42000, a He concentration of 400 appm and a damage dose of 1.6 dpa has been reached. This N[sub f] is by about a factor of two below the average N[sub f]-value of unirradiated reference tests, but seven times higher than N[sub f] of comparable postirradiated specimens. It was found, that at least at 420 C conventional postirradiation tests are a conservative ...

UK PubMed Central (United Kingdom)

The association of dietary glycaemic index (GI) and glycaemic load (GL) with cardiovascular diseases has been examined in several populations with varying results. We tested the hypothesis that...Full Text Available

International Nuclear Information System (INIS)

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

Energy Technology Data Exchange (ETDEWEB)

A new test methodology is described which allows access to loading rates that lie between split Hopkinson bar and shock-loading techniques. Gas gun experiments combined with velocity interferometry techniques have been used to experimentally determine the intermediate strain-rate loading behavior of Coors AD995 alumina and Cercom silicon-carbide rods. Graded-density materials have been used as impactors; thereby eliminating the tension states generated by the radial stress components during the loading phase. Results of these experiments demonstrate that the time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod. This allows access to intermediate loading rates over 5 x 10{sup 3}/s to a few times ...

Energy Technology Data Exchange (ETDEWEB)

The failure of receivers has been one of the main operating problems at the White Cliffs solar thermal power plant. This Technical Note reports the results of an initial investigation that identifies the cause as having been their thermal fatiguing of the tube walls. The fatigue appears to be caused by unstable heat transfer at vapor qualities below the point where critical heat flux is generally exceeded. Methods for avoiding this problem are tested.

Energy Technology Data Exchange (ETDEWEB)

The mechanical stability of diamond-like carbon (DLC) films coated on nitinol vascular stents was investigated under cyclic loading condition by employing a stent crimping system. DLC films were coated on the vascular stent of a three dimensional structure by using a hybrid ion beam system with rotating jig. The cracking or delamination of the DLC coating occurred dominantly near the hinge connecting the V-shaped segments of the stent where the maximum strain was induced by a cyclic loading of contraction and extension. However the failures were significantly suppressed as the amorphous Si (a-Si) buffer layer thickness increased. Interfacial adhesion strength was estimated from the spalled crack size in the DLC coating for various values of the a-Si buffer layer thickness.

International Nuclear Information System (INIS)

Turkish English ... Authors Sahin, O. (Suleyman Demirel University, Department of Physics, Isparta (Turkey))

International Nuclear Information System (INIS)

Reliability has an impact on wind energy project costs and benefits. Both life test data and field failure data can be used for reliability analysis. In wind energy industry, wind farm operators have greater interest in recording wind turbine operating data. However, field failure data may be tainted or incomplete, and therefore it needs a more general mathematical model and algorithms to solve the model. The aim of this paper is to provide a solution to this problem. A three-parameter Weibull failure rate function is discussed for wind turbines and the parameters are estimated by maximum likelihood and least squares. Two populations of German and Danish wind turbines are analyzed. The traditional Weibull failure rate function is also employed for comparison. Analysis shows that the three-parameter Weibull function can obtain more accuracy on reliability growth of wind turbines. ...

Energy Technology Data Exchange (ETDEWEB)

An effect of load conditions on Corrosion Fatigue Crack Propagation (CFCP) behavior of High Performance Steel (HPS) under seawater environment was investigated. Fatigue crack propagation tests under several load conditions including stress ratio and load frequency were conducted in air and 3.5% NaCl solution environments. Corrosion/fatigue ratio factor, C/F, particularly was defined to analyze the effect of such conditions. As shown in the results, a decrease of load ratio and frequency leads to an increase of C/F factor. Consequently, under lower loading frequency and stress ratio, the seawater condition causes much more significant effect on CFCP behavior of HPS.

International Nuclear Information System (INIS)

The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations.

Energy Technology Data Exchange (ETDEWEB)

Probabilistic assessment methods can be used to identify specific plant vulnerabilities. Application of such methods can also facilitate selection among system design alternatives available for safety enhancements. The quality of assessment results is however strongly dependent on realistic and accurate input data for modelling of system component behaviour and failure modes during conditions to be assessed. Use of conservative input data may not lead to results providing guidance on safety upgrades. Adequate input data for probabilistic assessments seems to be lacking for at least failure modes of some electrical components when exposed to a fire. This report presents an attempt to improve the situation with respect to such input data. In order to take advantage of information in existing documentation of fire incident occurrences some of the lessons learned from the fire at Browns Ferry Nuclear Power Plant on March 22, 1975 are discussed in ...

International Nuclear Information System (INIS)

Research is in progress to obtain a satisfactory creep ductility for alloy 800 when used as heat exchanger material in sodium-cooled fast reactors (LMFBR). The creep test characteristics at present available show that a pronounced tendency to reduced elongation by creep failure may arise after prolonged testing in the 500-700 deg C temperature range. This phenomenon is now agreed to be primarily inherent to the conditions for Ni_3(Ti,Al) precipitation in the material and hence to the Ti and Al concentrations. By structural studies and hardness measurements on material subjected to creep tests and taken from a large number of castings, the relationship was established between the (Ti+Al) content and the structural hardness effect of Ni_3(Ti,Al) at 600 deg C. Below a certain Ti+Al concentration, no precipitation occurs and hence the creep ductility to failure can be improved ...

CERN Document Server

Several types of X-band high power loads developed for several tens of MW range were designed, fabricated and used for high power tests at X-band facility of KEK. Some of them have been used for many years and few units showed possible deterioration of RF performance. Recently revised-design loads were made by CERN and the high power evaluation was performed at KEK. In this paper, the main requirements are recalled, together with the design features. The high power test results are analysed and presented

Wastenet

situ by isolating portions of the building envelope and performing tests .MAXIMUM ALLOWED LOAD ...and shall identify commissioning team members who will perform testing and prepare documentation.The commissioning agent may be

International Nuclear Information System (INIS)

Load-deflection characteristics of alumina and alumino-silicate fibrous blankets were experimentally determined. Load retention and springback capability of combinations of these materials were measured in a 10,000-hour test at surface temperatures of 650 to 1000"0C (1200 to 1832"0F). Experimental results are presented and future testing plans are discussed.

Energy Technology Data Exchange (ETDEWEB)

A test program was conducted under contract to Sandia National Laboratories to investigate water/steam effects on elevated temperature low cycle fatigue and creep-fatigue of Alloy 800. This report presents interpretation and analysis of the test results. Tubular specimens with water sealed inside were cycled to failure under strain control. Tests were conducted to 616K (650/sup 0/F) and 922K (1200/sup 0/F); some at 922K included tensile or compressive hold periods to simulate creep-fatigue conditions. The tubular specimens showed significantly lower lives than solid bar specimens cycled at equivalent strain ranges. Rough internal surfaces contributed to early crack initiation with these specimens. Inclusion of hold periods caused further large reductions in cycles to failure.

International Nuclear Information System (INIS)

TRIGA-SSR is a steady state research and material test reactor that has been in operation since 1980. The original TRIGA fuel was HEU (highly enriched uranium) with a U"2"3"5 enrichment of 93 per cent. Almost all TRIGA HEU fuel bundles are now burned-up. Part of the spent fuel was loaded and transferred to US, in a Romania - DOE arrangement. The rest of the TRIGA fuel bundles have to be temporarily stored in the TRIGA facility. As the storage conditions had to be established with caution, neutron and thermal hydraulic evaluations of the storage conditions were required. Some criticality evaluations were made based on the SAR (Safety Analysis Report) data. Fuel constant axial temperature approximation effect is usual for criticality computations. TRIGA-SSR fuel bundle geometry and materials model for SCALE5-CSAS module allows the introduction of a fuel temperature dependency for the entire fuel active height, using different materials for each ...

Energy Technology Data Exchange (ETDEWEB)

For a reliable design against fatigue failure of high-temperature components of different types of the heat resistant material Alloy 800, verified parameters of the low-cycle fatigue (LCF) behaviour are required. These parameters were obtained by a scatterband evaluation of the results of low-cycle fatigue tests, using a computerized data bank which includes all available actual data sets. The results of the evaluation are presented as mean fatigue curves with the upper and lower boundary limits of the scatterbands. For the type Alloy 800 in the recrystallization annealed condition, the results cover a temperature range from 20 to 750deg C; for the solution annealed types they cover a temperature range from 20 to 950deg C. Specimens tested in HTR helium at high temperatures had longer lives than specimens tested in air. This effect was represented quantitatively by the ratio of the total strain ranges ...

Energy Technology Data Exchange (ETDEWEB)

This Health and Safety (HSE) document offers technical information on the design of foundations for supports in offshore installations, and relates particularly to the North Sea. It is based largely on guidance offered earlier in Section 20 of the Fourth Edition of the Health and Safety Executive's 'Offshore Installations; Guidance on Design, Construction and Certification', which was withdrawn in 1998. The document contains a general section on foundations and the rest of the document comprises sections on: (a) piled foundations (planning, problems, pile make-up, steel stresses, design of pile foundations, axial pile capacity, factors of safety for piled foundations, load-deflection of piles, and piles for tethered buoyant structures); (b) foundations for gravity structures (foundation types, loads and reactions during installation, operating loads and reactions, foundation problems, cyclic ...

International Nuclear Information System (INIS)

The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1979. Tube failures occurred at 38 of the 93 reactors surveyed. Causes of these failures and procedures designed to deal with them are described. The defect rate was twice that in 1978 but still lower than the two previous years. Methods being employed to detect defects include increasing use of multifrequency eddy-current testing and a trend to full-length inspection of all tubes. To reduce the incidence of tube failures by corrosion, plant operators are turning to full-flow condensate demineralization and more leak-resistant condenser tubes. (author).

Science.gov (United States)

This paper describes the design of a test rig, which is used to apply a representative pressure load to a full-scale composite sandwich secondary aircraft structure. A generic panel was designed with features to represent those in the composite sandwich secondary aircraft structure. To provide full-field strain data from the panels, the test rig was designed for use with optical measurement techniques such as thermoelastic stress analysis (TSA) and digital image correlation (DIC). TSA requires a cyclic load to be applied to a structure for the measurement of the strain state; therefore, the test rig has been designed to be mounted on a standard servo-hydraulic test machine. As both TSA and DIC require an uninterrupted view of the surface of the test panel, an important consideration in the design is facilitating the optical access for the ...

International Nuclear Information System (INIS)

Tarapur Atomic Power Station 3 and 4 is a 540 MWe Pressurized Heavy Water Reactor. It uses 37 - element natural Uranium dioxide (UO_2) fuel pellets encapsulated inside the cylindrical sheath and are welded to the end plate at each end. During an postulated accident in which part of the fuel bundle are exposed to very high temperature (no means of heat removal) and other are at lower temperature (coolant temperature) possibility of failure of end plate weld due of thermal stresses developed by these relative temperature cannot be ruled out. In this report an attempt is made to study behaviour of fuel bundle under different temperature loading. Modelling of 37 element fuel bundle was done in ANSYS FEM. System was analysed for various sets of temperature loading. The system was analysed for plasticity and creep as material nonlinearity. The total strain, creep strain and stress increase as the temperature increases in upper ...

Energy Technology Data Exchange (ETDEWEB)

The Reliability and Availability Data System (RADS) is a database and analysis code, developed by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Nuclear Regulatory Commission (USNRC). The code is designed to estimate industry and plant-specific reliability and availability parameters for selected components in risk-important systems and initiating events for use in risk-informed applications. The RADS tool contains data and information based on actual operating experience from U.S. commercial nuclear power plants. The data contained in RADS is kept up-to-date by loading the most current quarter's Equipment Performance and Information Exchange (EPIX) data and by yearly lods of initiating event data from licensee event reports (LERS). The reliability parameters estimated by RADS are (1) probability of failure on demand, (2) failure rate during operation (used to calculate ...

Energy Technology Data Exchange (ETDEWEB)

A stochastic analysis is presented of the probability of overtopping of a dam. The discussion is based on the case of a dam for a small water storage reservoir which has recently been constructed in the Saar district in the FRG. The problem is first solved by means of a simulation method. However, it is possible to describe the result of the sumulation method by means of a much simpler model which is based on a solution of the failure integral of Freudenthal for uncorrelated resistances and loads. It is shown that the actual safety of this dam against overtopping is extremely sensitive to both the operation rule for the reservoir, and the freeboard allowance. Some general conclusions are derived from this study for assisting in the ongoing discussion of dam safety. (6 figs, 1 tab, 7 refs)

Science.gov (United States)

... failure at Goodwood and General Montgomery's continued failure to aggressively pursue the ground campaign. Air Chief ...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) bottom-loading transfer cask (BLTC) system is designed to provide ex-vessel fuel transfers of irradiated reactor components between the reactor containment building and the LMFBR shipping cask in the reactor service building. This system is being procured from National Lead Industries, Wilmington, Delaware, under management of Aerojet Manufacturing Company.

International Nuclear Information System (INIS)

Metastable austenitic steels show excellent mechanical properties, such as high strength combined with excellent ductility and toughness due to martensitic transformation under mechanical loading (transformation induced plasticity effect). A good energy consumption, and, in the case of high-alloyed metastable austenitic steels, a high corrosion resistance, increase the potential of these materials for diverse applications, also in regard of safety requirements. Up to now, numerous wrought alloys were investigated concerning mechanical behaviour, TRIP-effect, martensitic transformation behaviour and modelling of transformation kinetics or stress-strain behaviour. New high alloyed cast CrMnNi-steels, developed at Technical University Bergakademie Freiberg, provide the chance to reduce processing steps, production time and costs. In order to understand the influence of temperature on the martensitic phase transformation behaviour and therefore on mechanical properties ...

International Nuclear Information System (INIS)

Field Programmable Gate Arrays (FPGAs) are being used in space applications because of attractive attributes: good density, moderate speed, low cost, and quick turn-around time. However, these devices are susceptible to Single Event Upsets (SEUs). An approach using triple modular redundancy (TMR) and feedback was developed for flip-flop hardening in these devices. Test data showed excellent results for this circuit topology. Total dose and Single Event Effect (SEE) testing have been performed on recently released technologies. Failures are analyzed and test methodology is discussed.

Energy Technology Data Exchange (ETDEWEB)

The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminum matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of embryo-damage induced ...

Energy Technology Data Exchange (ETDEWEB)

Hydrogen (H{sub 2}) emissions characteristics of H{sub 2}-diesel dual fuel engine were measured using a 2004 turbocharged heavy-duty diesel engine with H{sub 2} supplemented into the intake air. The emissions of H{sub 2} were measured using an Electron Pulse Ionization (EPI) Mass Spectrometer (MS). The effect of the amount of H{sub 2} added, the engine load, and diesel fuel flow rates on the emissions of H{sub 2} and its combustion efficiency in the engine were investigated. The addition of H{sub 2} under high load operation was notable for its ability to obtain high H{sub 2} combustion efficiency and improve brake thermal efficiency. However, the addition of H{sub 2} at low load resulted in high emissions of H{sub 2} due to the failure to initiate and support a sufficiently vigorous flame for the complete combustion of H{sub 2} present outside the diesel spray plume. The maximum H{sub 2} emissions of ...

Energy Technology Data Exchange (ETDEWEB)

The solubilities of plutonium and uranium have been determined for alkaline salt solutions having compositions which bound those which will be processed in the In-Tank Precipitation (ITP) process. Loadings of plutonium and uranium onto monosodium titanate (MST) have been determined at temperatures bounding those expected to occur during ITP and using a salt solution which was determined to have the maximum solubility for uranium and plutonium. Fissile loadings increase with decreasing amounts of MST in contact with the salt solutions saturated in plutonium and uranium. At MST concentrations bounding those which are planned for the ITP process, expressions for the maximum loadings (wt %) are determined to be 0.29 - 0.20x[MST] for plutonium and 1.8 - 0.29x[MST] for uranium, where [MST] is the concentration of MST in grams/liter. These expressions are valid over the range of MST concentrations from 0.05 to 0.51 g/L and ...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) features a three-loop, sodium-cooled 400 MWt mixed oxide fueled reactor designed for the irradiation testing of fuels and materials for use in liquid metal cooled fast reactors. To establish the ultimate capability of a particular fuel design and thereby generate information that will lead to improvements, many of the fuel irradiations are continued until a loss of cladding integrity (failure) occurs. When the cladding fails, fission gas escapes from the fuel pin and enters the reactor cover gas system. If the cladding failure permits the primary sodium to come in contact with the fuel, recoil fission products can enter the sodium. The presence of recoil fission products in the sodium can be detected by monitoring for the presence of delayed neutrons in the coolant. It is the present philosophy to not operate FFTF when a failure has occurred that ...

Energy Technology Data Exchange (ETDEWEB)

BC Hydro recently conducted a demonstration test of a bearing condition monitor. The test, at the 529-MW Kootenay Canal project, proved the ability of the monitor to detect machine condition faults. The capability to detect changing conditions during normal operation of hydroelectric machines gives hydro plant owners the opportunity to anticipate needed maintenance and ultimately to reduce the number of equipment failures. BC Hydro intends to install bearing condition monitors, as well as windings monitors, brushgear monitors, environmental monitors, and other selected systems in as many as 46 of its hydro generators. BC Hydro analyzed forced outages between 1985 and 1989 in its hydro system to identify which parts of a generating unit resulted in the highest number of hours of outage. From there, the utility has formulated a concept for a machine condition monitoring system. To keep the system cost effective, it will be ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents the results of single-fiber pullout tests for deformed and smooth steel fibers embedded in the newly developed very-high strength concrete (VHSC) matrixes. The pullout test program involved four types of steel fibers, eight compressive strengths of VHSC matrixes, and two normal concrete strengths. Test results have shown that pullout behavior of different steel fiber reinforced VHSC composites is influenced by the matrix strength and fiber end condition (smooth, flat end, or hooked). Results reveal that both maximum pull-out load and total pullout energy increases as matrix strength increases for all deformed fibers that did not rupture. The test results also indicated that the increase in total pullout energy is more significant than that in peak load.

British Library Electronic Table of Contents (United Kingdom)

We have discovered a previously unidentified thermal explosion mode using the Los Alamos deflagration cylinder test (DFCT). The DFCT is a "pipe bomb"-style test similar to the detonation cylinder test (DTCT), which has been used for many years to calibrate detonation product equations of state. The shot is heated in an oven to a uniform test temperature. The pre-heated high explosive (HE) is triggered by a hot wire initiator on one end. The tube is back-illuminated by a bright light source, and its combustion-driven deformation and subsequent break-up are observed by a high-speed framing camera. Like the DTCT, the DFCT tube wall motion provides the primary diagnostic. A variety of reactive responses are possible, including quasi-steady deflagration and deflagration-to-detonation transition...

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A thesis is presented on improving the understanding of the fatigue properties of wood and fatigue failure mechanisms in the design of wind turbine blades. Three main areas were researched: the effect of R ratio on fatigue life, the effect of moisture on fatigue life and the development of cumulative damage laws. Tests were carried out on mainly four-ply laminates. Recommendations to future work are outlined. (U.K.).

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This report provides an assessment of the designs of turret and swivel systems for floating production, storage and offloading (FPSO) vessels and floating storage Units (FSU) which are either purpose built or converted from tankers. Use of FPSO and FSO in the North Sea with the move to subsea and deepwater production is discussed, and the background to FPSO and FSU turret systems is traced. Details are given of general issues relating to ship structure, systems affecting the turret, swivel systems, mooring systems, turret loading, scaffolding and support structure, on-board personnel, and construction standards. Turret system components and types are described, and failure modes, operation and safety relevant components are examined. Inspection and maintenance, examples of good and poor practice, and applicable regulations are considered. Annexes list UK installations and present information on individual turret design, fluid transfer systems, ...

International Nuclear Information System (INIS)

A nonlinear dynamic transient analysis merging hand calculations and the NASTRAN structural analysis computer code was conducted for a Fast Flux Test Facility in-reactor test assembly during an extremely unlikely design basis accidental event which is considered a Hypothetical Core Disruptive Accident (HCDA). The finite element modeling of the problem took advantage of NASTRAN's versatility to create loads and nonlinear elements not previously found in NASTRAN's library. The structural criteria for the test assembly to withstand an HCDA stipulates that the test assembly and its spoolpiece shall remain integral with the reactor head such that missiles are not generated.

Energy Technology Data Exchange (ETDEWEB)

The damping of unwanted oscillations in the generator units after a failure can be realized by installing a stabilizer between f.e. the revs of the generator and an input of the voltage regulator. The tuning of a Power System Stabilizer (PSS) is investigated using bode plots. Eigenvalue analysis shows an enlarged system stability margin. The method was tested on an advanced analogue power system simulator. As a result of these tests it appears to be useful to consider the stability as well as the optimal tuning. 5 figs., 6 refs.

British Library Electronic Table of Contents (United Kingdom)

Abstract Introduction. Spinal cord stimulation (SCS) is an effective procedure for the treatment of neuropathic extremity pain, with success rates approaching 70%. However, mechanical failures, including breakage and migration, can significantly limit the long-term effectiveness of SCS. A systematic analysis of surgical techniques was undertaken by a consensus group, coupled with extensive in vivo and in vitro biomechanical testing of system components. Methods. A computer model based on morphometric data was used to predict movement in a standard SCS system between an anchored lead and pulse generator placed in various locations. These displacements were then used to determine a realistic range of forces exerted on components of the SCS system. Laboratory fixtures were constructed to subj...

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Material testing of SPF-sheet is usually done with coupon hot tensile testing. The optimum range of strain rates is determined with stepped strain tests. To overcome the problem of very few available testing facilities and time consuming and costly procedure, cone cup testing has been developed since long. This test can be generated directly in the workshop, no machining of samples is necessary and it is very much related to the real SPF-process. The analysis of suitable temperature and strain rate is done by simple measurement of resulting cone height. This paper describes a unique and novel variant of the above mentioned baseline design. It provides on-line data of the actual status of the cone cup forming resulting from the applied, constant pressure. Strain rate variations as a result from texture or from the alloy-related behaviour is detectable. Thinning ...

British Library Electronic Table of Contents (United Kingdom)

The paper deals with the reliability-based design optimization (RBDO) of a riser support installed on a floating production storage and offloading (FPSO) unit under operation, extreme, damaged, and one line failure cases and installation loading conditions. The optimization problem is formulated such that probabilistic thickness variables described with random characteristics are determined by minimizing the weight of the riser support structure subjected to stress constraints for the given target reliability. The initial design model is generated based on actual FPSO riser support specifications. The finite element analysis is conducted using NASTRAN, and the probabilistic optimal solutions are obtained via the moving least squares method in the context of RBDO using a response surface me...

British Library Electronic Table of Contents (United Kingdom)

The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proximal tibia tunnels. One limb was implanted with HAp-coated PET graft, and the contralateral limb was implanted with non-HAp-coated PET graft as control. The rabbits were randomly sacrificed at four and eight?weeks after surgery. The loads to failure of the experimental group at eight?weeks were significantly higher than those of the control group (p?=?0.0057). Histologically, application of HAp coating induced new bone formation between graft and bone at eight?weeks compared with the controls. Rea...

Science.gov (United States)

Five cycles of loading, elution, and regeneration were performed to remove technetium from a Hanford waste sample retrieved from Tank 241-AW-101 using SuperLig 639 resin. The waste sample was diluted to 4.95 M Na plus and then was processed to remove 137Cs through dual ion exchange columns each containing 15 mL of SuperLig 644. To remove 99Tc, the cesium decontaminated solution was processed downwards through two ion exchange columns, each containing 12 mL of SuperLig 639 resin. The columns, designated as lead and lag, each had an inside diameter of 1.45 cm and a height of 30 cm. The columns were loaded in series, but were eluted and then regenerated separately. The average technetium loading for the cycles was 250 BV at 10 percent breakthrough. There was no significant difference in the loading performances among the five cycles. The percent removal of 99Tc was greater than 99.94 percent and the ...

Science.gov (United States)

Fabry Perot interferometry is a method of determining instantaneous velocities of an object in motion. The interferometer system is composed of the Fabry Perot interferometer, a laser, an electronic streak camera, and several focusing lenses. The first tests discussed were done on exploding bridgewire devices. During these tests, several system parameters were changed. These changes did not seem to affect the data, which appeared to be consistent. The second tests performed focused on slapper-type devices. It was determined that sandblasted, vapor-deposited aluminum on the slapper material would be required to yield quality data. Streak camera failure prevented much data from being collected. An effort is being made to replace the current streak camera. After it is replaced, a Fabry Perot and velocity interferometry system for any reflector comparison will be made. The results will be published as the ...

Energy Technology Data Exchange (ETDEWEB)

The use of deuterium-tritium fuel in the Compact Ignition Tokamak will require applying remote handling technology for ex-vessel maintenance and replacement of machine components. Highly activated and contaminated components of the fusion devices auxiliary systems, such as diagnostics and RF heating, must be replaced using remotely operated maintenance equipment in the test cell. In-vessel remote maintenance included replacement of divertor and first wall hardware, faraday shields, and for an in-vessel inspection system. Provision for remote replacement of a vacuum vessel sector, toroidal field coil or poloidal field ring coil was not included in the project baseline. As a result of recent coil failures experienced at a number of facilities, the CIT project decided to reconsider the question of remote recovery from a coil failure and, in January of 1990, initiated a coil replacement study. This study focused on the ...

Energy Technology Data Exchange (ETDEWEB)

Considering beryllium as plasma facing armour this paper presents recent results obtained in Russia. A special process of joining beryllium to a Cu-alloy material structure is described and recent results of thermal cycling tests of such joints are presented. Summarizing the results, the authors show that a Cu-alloy heat sink structure armoured with beryllium can survive high heat fluxes ({>=}10 MW/m{sup 2}) during 1000 heating/cooling cycles without serious damage to the armour material and its joint. The principal feasibility of thermal cycling of beryllium grades and their joints directly in the core of a nuclear reactor is demonstrated and the main results of this test are presented. The paper also describes the thermal cycling of different beryllium grades having cracks initiated by previously applied high heat loads simulating plasma disruptions. (orig.)

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S-120 white oils are used to impregnate insulation and fill high voltage wires. Cooling oil flows of specified viscosities can increase the load capacity of wires. White oils are studied for viscosities and dielectric properties. To meet requirements, S-220 type oils of different medium or low viscosities are tested. Capacity can be increased by viscosity adjustment. Tests were also made to select optimum stabilizing additives to keep low-viscosity.

Energy Technology Data Exchange (ETDEWEB)

A probability-based approach is presented as the integration of probabilistic methods and deterministic modelling based on the finite element method. An existing finite element software package was linked to an existing probabilistic package to analyse the complex mechanics that occur during the transient non-linear analysis of impact problems. This methodology is applied to a pipe whip analysis of a group-distribution-header, which results from a guillotine break, and subsequent impact with the adjacent building wall; this is a postulated accident for the Ignalina Nuclear Power Plant RBMK-1500 reactors. The uncertainties of material properties, component geometry data and loads were taken into consideration. The probabilities of failure of the impacted header and of the header support-wall were estimated given uncertainties in material properties, geometrical parameters and loading. The software ProFES was used for the ...

International Nuclear Information System (INIS)

In order to study the boundary conditions for the occurrence of ratcheting, a testing rig was erected. In this rig, small-scale mock-ups of the first wall were tested under mechanical conditions similar to those expected during disruptions. These mock-ups were made of stainless steel AISI 316. They were heated on the surface and water cooled from inside. Disruption forces were simulated by a high-speed hydraulic bending system by impact loads. The mock-ups were heated by a high-frequency generator and cooled by water through two cooling channels.In addition to the experimental work, simplified analytical analysis and numerical calculations were carried out using the finite element program ABAQUS. In these calculations, the temperature and stress fields in the mock-ups were investigated and the influence of the different constitutive equations was studied.The experimental results confirm the ratcheting behaviour predicted by ...

Energy Technology Data Exchange (ETDEWEB)

The failure rate of dashpots has been determined on the basis of the results of annually recurring function tests on hydraulic dashpots, in order to determine the effects of longer test cycles on the safety of systems GKN I and GKN II. The use of a calculation method made it possible to establish the number of defective dashpots in the system as a whole. A subsequent investigation illustrated the way in which this figure changes when the test interval is increased from four to ten years, and the effects of this on system safety. (orig.) [Deutsch] Zur Ermittlung der Auswirkungen verlaengerter Pruefzyklen auf die Sicherheit der Anlagen GKN I und GKN II wurde, basierend auf Ergebnisse der jaehrlichen Funktionspruefung an hydraulischen Stossbremsen, die Fehlerrate der Stossbremsen bestimmt. Mit Hilfe eines Berechnungsverfahrens konnte die Anzahl maengelbehafteter Stossbremsen in der Gesamtanlage bestimmt ...

Energy Technology Data Exchange (ETDEWEB)

The ability of the /sup 252/Cf-source-driven neutron noise analysis method to measure subcriticality has been demonstrated in a variety of experimental configurations of fissile materials. Calculations for an approximately 4-m-dia configuration of light water reactor (LWR) fuel elements indicated the feasibility of measuring the subcriticality of large, loosely coupled arrays of LWR fuel elements by this same method. These analysis suggested application to the initial loading of both pressurized and boiling water reactors, zero-power testing of reactors (such as shutdown margin measurements after initial loading), light water reactor refueling, and safe storage of LWR spent fuel. In the fuel storage application, direct measurement of subcriticality in the actual fuel storage facilities provides the parameter which is directly related to criticality safety.

Energy Technology Data Exchange (ETDEWEB)

The objective of the research was to develop a machine combination for harvesting of small wood, which carries out both the harvesting and forest haulage. The development was started in September 1995. The first prototype of the machine is ready. A Lokomo 910 forest tractor was acquired for the tests. The prototype has been mounted on the tractor, and the tests have been started in the beginning of March 1996. The reconstruction of the device will be made after the tests, as well as the description of different working praxis. Time consumption study and the analysis of it will be made after the equipment tests. The device consists of a grapple equipped with a guillotine cutting device mounted on the tractor. The actual felling is made stem by stem in the test phase. The stem can be forwarded directly into the load or it can be left aside, and new stems can be ...

International Nuclear Information System (INIS)

France began atmospheric nuclear testing at Mururoa and Fangataufa atolls in the South Pacific in July 1966. Following international protest, atmospheric testing ceased in August 1970. In late 1995, an International Geomechanical Commission (IGC) was created to assess the short- and long-term effects of underground nuclear testing on the stability and hydrology of Mururoa and Fangataufa. With the aid of its consultants, the Commission sought to develop its own understanding of the mechanics and consequences of the underground nuclear tests. It carried out extensive numerical analyses of shock wave effects, seismic wave propagation, slope stability and pre- and post-test hydrology. However, in its studies, the IGC was constrained to use the data made available to it by the French authorities. The Commission's report (International Geomechanical Commission 1998) has been submitted to ...

Energy Technology Data Exchange (ETDEWEB)

Damage and cyclic fatigue failure under alternating loading in transformation-toughened zirconia ceramics is reviewed and compared to corresponding behavior under quasi-static loading (static fatigue). Current understanding of the role of transformation toughening in influencing cyclic fatigue-crack propagation behavior is examined based on studies which altered the extent of the tetragonal-to-monoclinic phase transformation in MG-PSZ through subeutectoid aging. These studies suggest that near-tip computations of the crack-driving force (in terms of the local stress intensity) can be used to predict crack-growth behavior under constant amplitude and variable-amplitude (spectrum) loading, using spatially resolved Raman spectroscopy to measure the extent of the transformation zones. In addition, results are reviewed which rationalize distinctions between the crack-growth behavior of preexisting, ...

Energy Technology Data Exchange (ETDEWEB)

The 1977 version of the Simpson-Puls-Dutton model appears to be the most amenable with respect to utilizing known or readily estimated quantities. The Pardee-Paton model requires extensive calculations involving estimated quantities. Recent observations by Koike and Suzuki on vanadium support the general assumption that crack growth in hydride forming metals is determined by the rate of hydride formation, and their hydrogen atmosphere-displacive transformation model is of potential interest in explaining hydrogen embrittlement in ferrous alloys as well as hydride formers. The discontinuous nature of cracking due to hydrogen embrittlement appears to depend very strongly on localized stress intensities, thereby pointing to the role of microstructure in influencing crack initiation, fracture mode and crack path. The initiation of hydrogen induced failures over relatively short periods of time can be characterized with fair reliability using measurements of the ...

Energy Technology Data Exchange (ETDEWEB)

Experimental data on the material characteristics of structures subjected to thermal and mechanical cycling are needed for designing structural parts for creep and creep-fatigue interaction. Moreover, high-temperature low-cycle fatigue data are not sufficient to predict the fatigue creep lifetime. In order to check the reliability of steam generators, tests on pipe materials are conducted under cyclic thermal loading. The tests have been performed on an iron-nickel chromium alloy (alloy 800). Isothermal low-cycle fatigue tests have been conducted at 550 C. 15 refs.

Energy Technology Data Exchange (ETDEWEB)

The hydroelectric industry's recognition of the importance of avoiding unexpected failure, or forced outages, led to the development of probabilistic, or risk-based, methods in order to attempt to quantify exposures. Traditionally, such analysis has been carried out by qualitative assessments, relying on experience and sound engineering judgment to determine the optimum time to maintain, repair or replace a part or system. Depending on the nature of the problem, however, and the level of experience of those included in the decision making process, it is difficult to find a balance between acting proactively and accepting some amount of risk. The development of a practical means for establishing the probability of failure of any part or system, based on the determination of the statistical distribution of engineering properties such as acting stresses, is discussed. The capacity-demand analysis methodology, coupled with probablistic, ...

International Nuclear Information System (INIS)

BWRs are so designed that the exhaust steam from main steam safety relief valves is led to pressure suppression pools, and the steam is condensed in pool water, but at this time, dynamic load seems to arise in the pool water. In Tokai No. 2 Power Station, a Mark-2 containment vessel was adopted to improve the reliability as much as possible and to obtain the design with margin. In this report, the result of actual machine test in Tokai No. 2 Power Station and the method of reducing the load are described. When a relief valve works, the discharge of water in exhaust pipes into a suppression pool, the exhaust of air in exhaust pipes and repeated expansion and contraction of bubbles in pool water, and the exhaust of steam and condensation occur. As for the construction of the suppression pool in Tokai No. 2 Power Station, cross-shaped quencher and the structure with jet deflector were installed. The test ...

Energy Technology Data Exchange (ETDEWEB)

This task within the EU R and D for ITER was aimed at the development of basic manufacturing solutions for the high heat flux plasma facing components such as the divertor targets, the baffles and limiters. More than 50 representative small-scale mock-ups have been manufactured with beryllium, carbon and tungsten armour using various joining technologies. High heat flux testing of 20 of these mock-ups showed the carbon mono-blocks to be the most robust solution, surviving 2000 cycles at absorbed heat fluxes of up to 24 MW m{sup -2}. With flat armour tiles rapid joint failures occurred at 5-16 MW m{sup -2} depending on joining technology and armour material. These test results serve as a basis for the selection of manufacturing options and materials for the prototypes now being ordered. (orig.) 11 refs.

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy decided to terminate the Flywheel Rotor and Containment Technology Development project during FY 1983. Activities this year included fabrication, inspection, and test evaluation of rotor and containment structures. A peak energy of 700 Wh was stored at an energy density of 70 Wh/kg. In cyclic tests, 10,000 cycles from design speed to half speed were logged without failure. The first test of a lightweight containment structure indicates the need for additional development. In complementary studies, production cost estimates were made for three flywheel designs. In a cooperative program with the University of Wisconsin, work began on construction of a flywheel/continuously variable transmission/heat engine car which promises fuel economy improvements of up to 100%. Suggestions are made for the direction of future work when interest in flywheel system reappears.

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Manufacturers may be required to design transformers to overload specifications. Oil viscosity changes and loss variation with temperature are not accounted for in the industry loading guide. A comprehensive test program was performed using a winding assembly with imbedded thermocouples. Steady state and transient tests were performed for natural and non-directed forced oil circulation. The temperature distribution in the winding was not linear with height as usually assumed. A large number of temperature sensors is required to determine the hot spot location. The location of the hot spot was found to be different and less predictable for natural oil circulation compared with non-directed forced oil circulation especially during overload conditions. This paper reports that improved loading guide equations were developed to account for oil viscosity, resistance change, cooling duct oil rise, and location ...

International Nuclear Information System (INIS)

The decrease mechanic effect on loads being transported, shock load limiters (dampers) are being widely used today. Usually, the materials having 'stress-strain' diagrams (#sigma#-#epsilon#) of compression with a substantial portion, where #sigma# = const., are used as dampers. Most widely used are dampers made of foam polystyrene having just the same compression diagram. Similar strain diagrams can be enlisted for some porous materials, timber under cross compression, perforated metallic crushers and some others. By selecting damper material, the level of transmitted to the protected object pressures can be varied from several to hundreds MPa. Timber, as being widely used and featuring good technologic properties together with low cost, becomes an attractive material to be used as the limiter of shock loads. This paper presents the results of stress-strain sequoia properties (USA deliverable) and birch properties ...

International Nuclear Information System (INIS)

Process control transmitters that incorporate digital signal processing could be used advantageously in nuclear power plants; however, because such transmitters are too sensitive to radiation, they are not used. The Electric Power Research Institute sponsored work at Sandia National Laboratories under EPRI contract RP2614-58 to determine why SMART transmitters fail when exposed to radiation and to design and demonstrate SMART transmitter circuits that could tolerate radiation. The term ''SMART'' denotes transmitters that contain digital logic. Tests showed that transmitter failure was caused by failure of the complementary metal oxide semiconductors (CMOS)-integrated circuits which are used extensively in commercial transmitters. Radiation-hardened replacements were not available for the radiation-sensitive CMOS circuits. A conceptual design showed that a radiation-tolerant transmitter could be constructed. A prototype for ...

International Nuclear Information System (INIS)

This paper begins with an introduction to Guangdong Daya Bay Nuclear Power Station (GNPS) and gives a simple introduction to the operations and maintenance documentation system at GNPS. It then will review the maintenance program guidelines base and the associated problems prior to the application of reliability centered maintenance (RCM). How RCM was implemented at GNPS, how the results of RCM analysis were used to optimize the maintenance program and test program, and what is the interface between RCM and the existing maintenance program will be shown. Next, it will show the successful implementation of RCM at GNPS resulted in the following changes: A new understanding of equipment failure challenges operations and maintenance beliefs, maintenance concepts undergo a large change, maintenance program and periodic testing program are continuously modified and optimized, new on-condition maintenance technologies are ...

International Nuclear Information System (INIS)

Commissioning of a Pressurized heavy water reactor (PHWR) plant of NPCIL involves three phases viz phase-A which consist of pre-criticality activities such as hydro test, air hold test, no load test of motors etc., phase-B consist of criticality and post criticality physics experiments. The phase-C, which is considered the major phase, consist of initial power raise to about 10 % , TG rolling, synchronization, going to significant power in steps and performance tests such as load rejection tests from various power levels. In order to have smooth commissioning for the Phase-C, an integrated team consisting of engineers from various design and analysis groups of NPCIL headquarters was formed to participate along with site O and M engineers, closely observe and coordinate phase-C commissioning activities. During this commissioning some major ...

International Nuclear Information System (INIS)

The MACSTOR/KN-400 of Wolsung power plant in Korea is a dry interim storage facilities. There are 400 long slender cylinders in MACSTOR/KN-400. In one cylinder, ten baskets where Candu spent fuels are loaded are stacked and stored. For this MACSTOR/KN-400 facilities, analyses and tests for the hypothetical accident conditions that might happen during moving and storing baskets into a cylinder were performed. The hypothetical accident conditions to be considered are two cases. One is the case of basket dropping onto the bottom plate of a cylinder. The other is the case of basket dropping onto the other basket top plate stored in the cylinder. For the drop analyses, the case of hanging cylinder and the case of cylinder on the unyielding target surface were considered. Based on the dropping analysis, testing condition was determined as the latter case that is for the cylinder on the target surface. In a basket, 60 dummy fuel ...

Energy Technology Data Exchange (ETDEWEB)

Due to the cyclical human life, utility loads appear to be cyclical too. During daytime when most factories are in operation, the electricity demand is very high. On the contrary, when most people are sleeping from midnight to daybreak, the electric load is very low, usually only half of the peak load amount. To meet this large gap between peak load and light load, utilities must idle many generation plants during light load period while operating all generation plants during peak load period no matter how expensive they are. This low utilization factor of generation plants and uneconomical operation have sparked utilities to invest in energy storage devices such as pumped storage plants, compressed air energy storage plants, battery energy storage systems (BES) and superconducting magnetic energy storage systems (SMES) etc. Among these, ...

International Nuclear Information System (INIS)

In General Electric's design of the Simplified Boiling Water Reactor (SBWR), The depressurization valves (DPV) are installed in the reactor pressure boundary: four are connected to the reactor vessel by means of nozzles, and two more are located on the main steam pipes (one DPV for each line), which act during particular transients and/or loss of coolant accidents (LOCA), consequently providing the reactor vessel with a safe quick depressurization system. Once the vessel is de pressurised, the passive gravity-driven cooling system (GDCS) starts to operate, permitting the injection of water required for continuous core cooling. DPVs are leak tight, with welded flaps, actuated by a [striker[hammer***] which is activated by an explosive mixture. The dynamic loads that open these valves include, in addition to those produced by steam (typical in any thermodynamic transient with open/close valves), other important loads that are characteristic of ...

Energy Technology Data Exchange (ETDEWEB)

Polymers are required to use in radiation environments as insulation materials. However, they often suffer from tracking failure. There is an increasing demand to evaluate radiation effects on dielectric performance. This paper presents a recurrence plot (RP) approach to analyse surface discharge sequences of gamma-ray irradiated polymer materials based on tracking test. Studying the non-linear characteristics of discharge sequences can assist in understanding the underlying mechanism of the discharge process. Discharge sequences of the test are extended to m-dimensional phase space by using the phase space reconstructed method. As test samples, polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN) were irradiated to 100 kGy and then up to 1 MGy with a dosage rate of 10 kGy h{sup -1} by using a {sup 60}Co gamma source. The tracking tests were carried out according to ...

International Nuclear Information System (INIS)

An experimental technique is described which allows for parametric investigations of transient behavior of mobile core materials in a fuel bundle geometry. For the out-of-pile simulation of energy releases resulting from mild TOP- or LOF-accidents the exothermic reaction of an aluminium-oxide-thermite is used. Transient material relocation inside the test section is recorded by X-ray-cinematography. Results of some experiments recently performed close to conditions expected to be achieved during mild TOP-accidents are described in detail.

Energy Technology Data Exchange (ETDEWEB)

The data center in this study had a total floor area of 3,024 square feet (ft{sup 2}) with one-foot raised-floors. It was a rack lab with 147 racks, and was located in a 96,000 ft{sup 2} multi-story office building in San Jose, California. Since the data center was used only for testing equipment, it was not configured as a critical facility in terms of electrical and cooling supply. It did not have a dedicated chiller system but was served by the main building chiller plant and make-up air system. Additionally it was served by only a single electrical supply with no provision for backup power in the event of a power outage. The Data Center operated on a 24 hour per day, year-round cycle, and users had full-hour access to the data center facility. The study found that data center computer load accounted for 15% of the overall building electrical load, while the total power consumption attributable to the data center ...

Energy Technology Data Exchange (ETDEWEB)

To determine the accuracy of the intra-articular location of hyaluronic acid injection using a blind approach and to establish the usefulness of fluoroscopy-guided intra-articular injection. A fluoroscopy unit was used for 368 intra-articular injections of hyaluronic acid to 93 knees in 65 patients. Initially, blind needle positioning was conducted on the fluoroscopy table. The failure rate of the blind approach among the 368 injections was evaluated, and a relationship between the Kellgren-Lawrence grade (K-L grade) and the incidence of repeated failures using the blind approach was determined for injections to 52 knees in 37 patients who received a complete cycle of injections (five consecutive injections with a one-week interval between injections). Using a blind approach, 298 of 368 trials (81.2%) resulted in a needle tip being placed in an intra-articular location, while 70 of 368 trials resulted in an extra-articular placement of the ...

Energy Technology Data Exchange (ETDEWEB)

Automated, variable volume unloaders provide the ability to smoothly load/unload reciprocating compressors to maintain ideal operations in ever-changing environments. Potential advantages provided by this load control system include: maximizing unit capacity, optimizing power economy, maintaining low exhaust emissions, and maintaining process suction and discharge pressures. Obstacles foreseen include: reliability, stability, serviceability and automation integration. Results desired include: increased productivity for the compressor and its operators, increased up time, and more stable process control. This presentation covers: system design features with descriptions of how different types of the devices were developed, initial test data, and how they can be effectively operated; three actual-case studies detailing the reasons why automated, hydraulically controlled, variable volume, head-end unloaders were chosen over ...

Energy Technology Data Exchange (ETDEWEB)

Discontinuously reinforced aluminium-based composites containing particulate or whisker SiC reinforcements at different volume fractions, were produced via a powder-route. Isothermal creep tests have been carried out at 270, 300 and 320 C. During these tests axial and transverse strains were monitored using a non-contacting laser scanning extensometer arrangement. At the same time neutron diffraction has been used to measure the elastic phase strain evolution with composite creep deformation. It was found that after the initial loading the phase strains remained essentially constant during primary and secondary creep. This indicates that the initial matrix/reinforcement inelastic misfits remain largely unchanged, probably due to the setting up of a dynamic equilibrium between misfit generation and stress relaxation. For each system, the neutron data has been combined with Eshelby modelling to obtain a measure of the ...

Energy Technology Data Exchange (ETDEWEB)

The behavior of MEMS devices is limited by the strength of critical features such as thin ligaments, oxide cuts joining layers, pin joints and hinges. Devices fabricated at Sandia's Microelectronic Development Laboratory have been successfully tested to investigate these features. A series of measurements were performed on samples with gage lengths of 15 to 1000 microns, using conventional and tungsten coated samples as well as samples that include the critical features of standard components in the test section. Specimens have a freely moving pin joint on one end that anchors the sample to the silicon die to allow rotation to reduce effects of bending. Each sample is loaded in uniaxial tension by pulling laterally with a flat tipped diamond in a computer-controlled Nanoindenter. Load is calculated by resolving the measured lateral and normal forces into the applied tensile force and frictional ...

Science.gov (United States)

The reverse approach to critical (RAC) experiments were performed in the ZPR-IX critical facility at Argonne National Laboratory. One of the major objectives of this project is to determine the adequacy of the low-level flux monitor (LLFM) detectors for initial loading of the Fast Flux Test Facility (FFTF). 5 references. (auth)

International Nuclear Information System (INIS)

The design characteristic of the autocontrol technique of the combined centrifuge is introduced. Digital technique, vary structure control and interface technique, graphical display techniques, digital communication technique as well as electronic technique are applied in the course of research. Automation in the operation of large scale combined centrifuges and the course of combined test has been realized and it can coordinate with other systems of status monitoring, data collecting and centrifugal force-aerodynamic force matched load automatically

International Nuclear Information System (INIS)

The critical part of the trimetallic transition joint (type 304 stainless steel/Alloy 800/2.25 Cr-1 Mo steel), the Alloy 800/2.25 Cr-1 Mo steel joint welded with Inconel 182, was subjected to thermal cycling between room temperature and 873 K. The thermal cycling test procedure used produces accelerated failures in transition joints similar to those observed in steam generators of operating power plants. On thermal cycling, precipitation at the weld/ferritic steel interface decreased on post-weld heat treatment. This precipitation increased with increased prior ageing and applied stress. The results of these tests indicated a considerable improvement in performance of the trimetallic transition joint compared to the direct (bimetallic) transition joint. (orig.).

Energy Technology Data Exchange (ETDEWEB)

In cold countries, the design of transmission lines and communication networks requires the knowledge of ice loads on conductors. Atmospheric icing is a stochastic phenomenon and therefore probabilistic design is used more and more for structure icing analysis. For strength and reliability assessments, a data base on atmospheric icing is needed to characterize the distributions of ice load and corresponding meteorological parameters. A test site where icing is frequent is used to obtain field data on atmospheric icing. This test site is located on the Mt. Valin, near Chicoutimi, Quebec, Canada. The experimental installation is mainly composed of various instrumented but non-energized test cables, meteorological instruments, a data acquisition system, and a video recorder. Several types of icing events can produce large ice accretions dangerous for land-based structures. They are ...

Energy Technology Data Exchange (ETDEWEB)

For quantitative acquisition of the influence of surface decarburizing phenomena on the failure of construction parts under cyclic stress different surface decarburization stages were generated in the steels 42CrMo4 and 100Cr6. After construction part-specific thermal treatment the generated states of residual stress were then determined and life span-oriented fatigue tests were conducted. The studies showed that already a small decarburization in martensitic material conditions of the steels 42CrMo4 and 100Cr6 led to a reduction of the alternating bending strength. The decrease of alternate strength can be associated with the micro-notch effects caused by the internal oxides formed by surface oxidation and/or the residual tension stress developed during the hardening in sub-surface sample areas. Decarburization degrees of more than 50% cause a noticeable decrease of surface stability, an increase of residual tension stresses close to the ...

Energy Technology Data Exchange (ETDEWEB)

Corrosion in drilling and well stimulation is described in relation to acid corrosion inhibition, acid inhibitors, acetylenic inhibitors, synergistic blends, metallurgy, wellbore tubulars, coiled tubing, and high alloy tubular materials. Acidizing is a procedure for stimulating oil and gas wells. Factors that have an important influence on the reaction rate and the way in which acid reacts with rock include temperature, acid concentration, acid volume, injection velocity, acid viscosity, and fluid loss properties of the formation. The cost of drill pipe failures are $1 per fot of hole drilled, which is a significant fraction of the drilling cost. Steps in a test procedure are listed, as well as factors which determine the extent of acid corrosion in a given situation including acid type and strength, metal type, temperature, contact time; pressure, and volume/surface area ratio. Underbalanced drilling is a method for completing oil and gas ...

Energy Technology Data Exchange (ETDEWEB)

The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a ...

Energy Technology Data Exchange (ETDEWEB)

Certain innovative coke-oven repair techniques are reviewed that represent an engineered approach to a successful rehabilitation of all types of coke-oven batteries. These techniques have been developed during the last 10 years and experience gained on a number of repair projects has shown that these techniques operate as a cohesive and comprehensive method of end flue and through-wall repairs to gain additional years of operating life to coke-oven batteries. Extended operations approaching 10 to 15 additional years of service at lower costs than a pad-up rebuild and, while meeting the environmental emission regulations, are attainable using the techniques of: Proper tie-in joint preparation; Improved bricking up methodology; Preheating refractory during bricking up; Installation of spring-loaded bracing system; and installation of flexible coke-oven doors. Repair methods that do not incorporate the above techniques are subject to premature ...

Energy Technology Data Exchange (ETDEWEB)

Results indicate that the probability of double-ended guillotine break (DEGB) in the reactor coolant loop piping of Westinghouse and Combustion Engineering plants is extremely low. It is recommended that the NRC seriously consider eliminating DEGB as a design basis event for reactor coolant loop piping in Westinghouse plants. Pipe whip restraints on reactor coolant loop piping could then be excluded or removed, and the requirement to design supports to withstand asymmetric blowdown loads could be eliminated. It is also recommended that the current requirement to couple safe shutdown earthquake (SSE) and DEGB be eliminated. Recognizing however that seismically induced support failure is the weak link in the DEGB evaluation, it is recommended that the strength of component supports, currently designed for the combination of SSE plus DEGB, not be reduced. The study indicates that the probability of DEGB in reactor coolant loop piping is ...

Energy Technology Data Exchange (ETDEWEB)

A model is presented which describes the formation of surface damage ``gouging`` on the rails that guide rocket sleds. An unbalanced sled can randomly cause a very shallow-angle, oblique impact between the sled shoe and the rail. This damage phenomenon has also been observed in high-velocity guns where the projectile is analogous to the moving sled shoe and the gun barrel is analogous to the stationary rail. At sufficiently high velocity, the oblique impact will produce a thin hot layer of soft material on the contact surfaces. Under the action of a normal moving load, the soft layer lends itself to an anti-symmetric deformation and the formation of a ``hump`` in front of the moving load. A gouge is formed when this hump is overrun by the sled shoe. The phenomenon is simulated numerically using the CTH strong shock physics code, and the results are in good agreement with experimental observation.

British Library Electronic Table of Contents (United Kingdom)

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a PEM fuel cell. The analysis of this process requires determination of the effective thermal conductivity as well as the thermal contact resistance associated with the interface between the GDL and adjacent surfaces/layers. In the present study, a custom-made test bed that allows the separation of effective thermal conductivity and thermal contact resistance in GDLs under vacuum and ambient conditions is described. Measurements under varying compressive loads are performed using Toray carbon paper samples with a porosity of 78% for a range of thicknesses. The measurements are complemented by compact analytical models that achieve good agreement with experimental data. A key finding is that ...

Energy Technology Data Exchange (ETDEWEB)

A scheme for controlling multimanipulator systems is presented. The control objective is to coordinate the manipulators to perform parts-matching tasks such as screwing a nut onto a bolt. The task of moving a rigid object can be treated as a special case. Two secondary control objectives internal force control and load distribution can be accomplished within the structure of the control law. The internal force control mechanism keeps the internal forces on the object being manipulated at a desirable level. The load distribution mechanism distributes control effort to each manipulator according to a weighting factor. It is also shown that the control algorithm has a modular structure which facilitates its implementation on a multiprocessor computer. The scheme was tested on a planar scara type dual-manipulator system. A series of experimental results is included to demonstrate the system performance under various conditions.

Energy Technology Data Exchange (ETDEWEB)

The two tank (125,000kl each) foundations under construction are as large as 85m in diameter, and the north-side tank is to be placed over a sharper slope. The tanks are greatly different in their height from the rockbed since they are to be placed at the same level. For reduction in construction cost and time, a pile foundation design is chosen as the basic concept for foundation construction. After an overall evaluation of stability upon exposure to seismic torsion and of the deformation characteristics of piles and concrete slabs, a total pile foundation design with rock debris replaced with crushed rock is determined to be the design to be adopted. Since the piles to be driven in are greatly different in length, error in the pile supporting force will be too grave under the conventional pile landing control system. Therefore, a high-accuracy pile landing control system is employed, established after a rapid load test in addition to the ...

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions ...

Energy Technology Data Exchange (ETDEWEB)

The tribo characteristics of self-lubricating 40-mm-bore ball bearings with a retainer of glass cloth-polytetrafluoroethylene (PTFE) laminate, which has elliptical pockets with a large pocket clearance, were tested under thrust loads at speeds up to 50,000 rpm, 2 million DN, in liquid hydrogen (LH2) and in liquid nitrogen (LN2). During testing, the bearing torque, outer-race temperature, and electric resistance between the inner and outer races were monitored to verify the formation and rupture of a PTFE transfer film. Testing showed that the bearings having the elliptical retainer pockets were superior to the conventional bearings with circular pockets. It was determined that, at the maximum inner race spinning velocity of about 5 m/s, a PTFE transfer film could sustain the maximum Hertz stress, up to about 2000 N/sq mm, in LH2, without severe film rupture resulting in bearing seizure. In LN2, the ...

Energy Technology Data Exchange (ETDEWEB)

A 308-size hybrid ball bearing, with ceramic balls and steel rings, was tested using a diester oil and gas turbine fuel as lubricants at several speeds and loads. Heat generation data from this test work was then correlated with the heat generation model from a widely used computer code. The ability of this hybrid split inner ring bearing design to endure thrust reversals, which are expected in many turbine applications, was demonstrated. Finally, the bearing was successfully endurance tested in JP-10 fuel for 25 hours at 7560 N axial load and 36,000 rpm. This work has successfully demonstrated the technology necessary to use fuel-lubricated hybrid bearings in limited-life gas turbine engine applications such as missiles, drones, and other unmanned air vehicles (UAVs). In addition, it has provided guidance for use in designing such bearing systems. As a result, the benefits of ...

Energy Technology Data Exchange (ETDEWEB)

Analyses of the date obtained from the instrumented impact test and of its correlation with static and dynamic J integral values and various tensile properties are made in this study. It is shown that a dynamic bending yield load recorded in the instrumented Charpy V test can be easily converted to a dynamic tensile yield stress using Server's equation. It is also possible to estimate a true fracture strain, COD value, and SZW easily if the load point displacement is recorded. Temperature dependency of Charpy V energy and J integral values is rather well simulated by a curve fitting method. However, a half value transition temperture obtained in that method has no physical meaning. Dynamic J sub(ID) is larger than a static J sub(IC) in the ductile fracture range in this study. This rise is proportional to the yield stress ratio sigmasub(yd)/sigmasub(y)(--1.2-1.3). It is found, therefore, that ...

Energy Technology Data Exchange (ETDEWEB)

Fretting wear test in room temperature water was performed to evaluate the wear coefficient of CANDU (CANadian Deuterium Uranium) steam generator (SG) tube material (Alloy 800) against 410 type martensitic stainless steels. The main focus is to compare the wear behaviors between Alloy 800 and Inconel 690. Test conditions are 10{approx}30N of normal load, 200{approx}450mm of sliding amplitude and 30Hz of frequency. The result indicated that the wear rate of Alloy 800 was higher than those of Inconel 690 at various test condition such as normal loads, sliding amplitudes etc. From the results of SEM observation, there was little evidence of plastic deformation layer that were dominantly formed on the worn surfaces of Inconel 690. Also, wear particles in Alloy 800 were released from contacting asperities deformed by severe plastic flow during fretting wear. Main cause of wear rate ...

Energy Technology Data Exchange (ETDEWEB)

A press formability of magnesium alloy sheet cannot be evaluated by only general characteristics in tensile test; tensile strength, elongation n-value and r-value. For example, AZ31-alloy elongates about 20% in room temperature but breaks easily at shallow stage in deep drawing, which is caused by little local elongation (local necking). Crystallographic restriction of slip deformation in this alloy produces high strength, which almost equal to macroscopic fracture strength. In press forming, the bending under high tension requires a large deformability. A great difference in the deformability between AZ31 magnesium alloy and a strain hardened A1100 Aluminum (only 5% in elongation) is shown by static bending test with V-notch. In a rolled plate of AZ31, a crack is produced by stress concentration and propagates with reduced load at all testing temperature up to 453 K. In contrast, the point of notch in ...

Energy Technology Data Exchange (ETDEWEB)

High energy piping systems are operated with either or both conditions of maximum operating temperature exceeding 200 .deg. F(93.3 .deg. C) or maximum operating pressure exceeding 275 psig(19.3kg/cm{sup 2}) during normal operating conditions in nuclear power plants. A high energy pipe failure is postulated in branches or piping that runs larger than one inch nominal diameter. The resultant consequences of these postulated pipe breaks must be analyzed for the effect on maintenance of plant safe shutdown capability, containment integrity. And the analyzed results must be applied to the system design so that a pipe failure can not damage essential systems to an extent of impairing design function nor affect necessary component operability. The considerable effects of pipe break are as follows; dynamic effects such as pipe whip, jet impingement and environmental impact by release of system contents. Two types of forces are occurred by the pipe ...

Energy Technology Data Exchange (ETDEWEB)

The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Information has been presented by a number of researchers, which indicated that those tests may be inappropriate for examining microbial degradation of cement-solidified LLW. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program was to develop modified microbial degradation ...

UK PubMed Central (United Kingdom)

Heart failure affects nearly 6 million Americans, with a half-million new cases emerging each year. Whereas up to 50% of heart failure patients die of arrhythmia, the diverse mechanisms underlying...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Titanium alloys are characterized by poor tribological properties, and the traditional use of titanium alloys has been restricted to nontribological applications. The deposition of a well adherent diamond coating is a promising way to solve this problem. In this study, the tribological properties of diamond-coated titanium were studied using a pin-on-disk tribometer, and the results were compared with those of pure titanium and plasma nitrided titanium. The tribological behavior of pure titanium was characterized by high coefficient of friction and rapid wear of materials. Plasma nitriding improved the wear resistance only under low normal load; however, this hardened layer was not efficient in improving the wear resistance and the friction properties under high normal load. Diamond coating on pure titanium improved the wear resistance of titanium significantly. Surface profilometry measurement indicated that little or no wear of the diamond ...

Energy Technology Data Exchange (ETDEWEB)

In order to establish the optimum fueling in a natural gas fueled dual fuel engine, tests were made for some operational parameters and their combination on the engine performances and the exhaust emissions. The results show that the gas oil quantity should be increased and gas oil injection timing should be advanced to suppress unburned hydrocarbon emission at middle and low output range, while the quantity should be reduced and the timing should be retarded to avoid onset of knock at high loads. The unburned hydrocarbon emission and the thermal efficiency are improved at the same load avoiding too lean natural gas premixture by restriction of intake charge air. However the improvement is limited because the ignition and initial combustion of pilot diesel fuel is deteriorated when the cylinder pressure is excessively lowered by throttling. The increase in pilot gas oil amount is effective for low-load ...

Energy Technology Data Exchange (ETDEWEB)

The magnetically controlled plasma opening switch (MCPOS) is an advanced plasma opening switch that utilizes magnetic fields to improve operation. Magnetic fields always dominate terawatt, pulsed power plasma opening switches. For that reason, the MCPOS uses controlled applied magnetic fields with magnitude comparable to the self-magnetic field of the storage inductor. One applied field holds the plasma in place while energy accumulates in the storage inductor, then another applied field pushes the plasma away from the cathode to allow energy to flow downstream. Over a ten month period, an MCPOS was designed, built, and tested on DECADE Module 2 at Physics International. The peak drive current was 1.8 MA in 250 ns. The output parameters were up to 1 MA into an electron beam load. The radiation temporal pulse width averaged 60 nanoseconds full-width at half-maximum. The peak load voltage ranged from one to two megavolts. The ...

Energy Technology Data Exchange (ETDEWEB)

The fluid-induced vibration level of instrumented capsule, which was manufactured for fuel irradiation test at the reactor core of HANARO, was investigated. For this purpose, the instrumented capsule was loaded at the OR site of the HANARO design verification test facility that could simulate identical flow condition as the HANARO core. Then, vibration signals of the instrumented capsule subjected to various flow conditions were measured by using vibration sensors. In time domain analysis, maximum amplitudes and RMS values of the measured acceleration and displacement signals were obtained. By using frequency domain analysis, frequency components of the fluid-induced vibration were analyzed. In addition, natural frequencies of the instrumented capsule were obtained by performing modal test. The frequency analysis results showed that the natural frequency components near 7.5Hz and 17.5Hz were dominant in ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes the test results on high-temperature strength properties of fire resistant steel(FR steel) for building, the formulation, and the examples of application to member tests and actual buildings. Because of its components and manufacturing method, FR steel excels in strength at elevated temperature due to precipitation and dispersion strengthening. Tests on high temperature properties of FR steel showed that every property such as strength, stress-strain curve, elastic modulus, and creep performance at high temperature was superior to those of conventional steels. Then, it was confirmed in the tensile tests at room temperature and high temperature after heat history that FR steel could be reused after fire. It was also found in the member tests that columns and beams of FR steel could support loadings equivalent to long-term allowable unit ...

UK PubMed Central (United Kingdom)

Heart failure has been singled out as an emerging epidemic, which could be the result of increased incidence and/or increased survival leading to increased prevalence. Knowledge of the responsibility...Full Text Available

Science.gov (United States)

Ultimate compressive strength and failure modes were studied using 24- ... to 81 % of the average ultimate compressive strength (UCS). Figure 1 (a) is the failure ...

UK PubMed Central (United Kingdom)

Diagnostic accuracy of the currently available serum markers of cardiac injury, such as myoglobin, creatine kinase and its myocardial isoform, are altered in patients with renal failure. It is shown...Full Text Available

International Nuclear Information System (INIS)

One of the limiting contributors to the heat load constraint for the Yucca Mountain repository is the decay of Americium 241. A possible option to reduce the heat load produced by Am-241 is to eliminate or transmute it in a light water reactor thermal neutron environment, particularly, by taking advantage of the thermal fission cross section of Am-242 and Am-242m. In this study we employ lattice loading optimization techniques to define the americium/uranium blending and pin arrangements via an adaptation of the code FORMOSA-L to include the incineration of preloaded americium as an objective function. The optimization routines were designed to maximize americium transmutation, while maintaining power peaking below a predefined constraint. The viability of these lattice designs has been analyzed by creating bundles with these Am-spiked lattices and by loading these bundles into realistic 3D BWR ...

Energy Technology Data Exchange (ETDEWEB)

Three different configurations of cylindrical submerged media anaerobic reactors (SMARs) with packing volumes of 85 items were operated at 35 C for 415 days with COD loading rates varying from 1 to 12 g/l/d and three retention times of 0.5, 1, and 2 days. A synthetic waste consisting of a milk solution with a mineral supplement was used for the feed. Tracer studies on clean-bed and dirty-bed SMARs indicate that reactor configuration, biogas mixing, and biomass accumulation all have a significant effect on SMAR hydraulics and cause short-circuiting. Based on the isothermal energy dissipation theory, the higher hydrostatic pressures resulting from higher SMAR heights increases self-induced biogas mixing and improves the contact efficiency between substrate and organisms. Based on TCOD removal rate, the tallest SMAR performed slightly better at COD loading rates above 4/g/l/d. At COD loading rates equal to or below 4 g/l/d, ...

Energy Technology Data Exchange (ETDEWEB)

This article presents the comparative bench testing results of a naturally aspirated, four stroke, four cylinder, water cooled, direct injection Diesel engine when running on diesel fuel and shale oil that is produced in Estonia from local oil shale. The purpose of this research is to investigate the possibility of practical usage of the shale oil as the alternative fuel for a high speed Diesel engine as well as to evaluate the combustion efficiency, brake specific fuel consumption, emission composition changes and the smoke opacity of the exhausts. Test results show that when fuelling a fully loaded engine with shale oil, the brake specific fuel consumption at the maximum torque and rated power is correspondingly higher by 12.3% and 20.4%. However, the brake thermal efficiencies do not differ widely and their maximum values remain equal to 0.36-0.37 for Diesel fuel and 0.32-0.33 for shale oil. The total nitrogen oxide ...

Science.gov (United States)

The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program is to develop modified microbial degradation test procedures that will be more appropriate than the existing procedures for evaluating the effects of microbiologically influenced chemical attack on cement-solidified LLW. ...

Energy Technology Data Exchange (ETDEWEB)

This report is the first of four volumes that identify and assess the environmental, health, and safety issues involved in using sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles that may affect the commercialization of Na/S batteries. This and the other reports on recycling, shipping, and vehicle safety are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD D) program for Na/S battery technology. The reports review the status of Na/S battery RD D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers cell design and engineering as the basis of safety for Na/S batteries and describes and assesses the potential chemical, electrical, and thermal hazards and risks of Na/S cells ...

British Library Electronic Table of Contents (United Kingdom)

Difficulty in recalling the names of people is very common in the early stages of Alzheimer's disease and in mild cognitive impairment (MCI). However, it is not known whether the difficulty in naming people in MCI reflects problems associated with lexical access or with semantic access. The aims of the present study were to investigate semantic and phonological access to proper names by use of a Tip-of-the-tongue (TOT) task in individuals with multidomain amnestic MCI, individuals with amnestic MCI, and healthy controls, as well as to study the relationships between TOT production and performance in a free recall verbal memory test. In the individuals with multidomain amnestic MCI, the main process affected was phonological access; failures in phonological access were related to deficits i...

Science.gov (United States)

The Darrieus-type Vertical Axis Wind Turbine (VAWT) presents a variety of unusual structural problems to designers. The level of understanding of these structural problems governs, to a large degree, the success or failure of today's rotor designs. A survey is presented of the technology available for rotor structural design with emphasis on the DOE research program now underway. Itemizations are included of the major structural issues unique to the VAWT along with discussion of available analysis techniques for each problem area. It is concluded that tools are available to at least approximately address the most important problems. However, experimental data for confirmation is rather limited in terms of volume and the range of rotor configurations tested.

British Library Electronic Table of Contents (United Kingdom)

Soluble TWEAK is a member of the TNF-alpha family of cytokines that has been shown to predict mortality in patients with heart failure. Pulmonary artery hypertension is a devastating disease, in which right ventricular function has been shown to be the major determinant of prognosis. In this hypothesis-generating study, we sought to evaluate the potential usefulness of sTWEAK in the prediction of disease severity in patients with pulmonary artery hypertension. We therefore conducted a retrospective analysis of sTWEAK serum levels in 95 stable patients with PAH. For all patients data on hemodynamic parameters, biomarkers and functional exercise tests were available. Compared to controls, patients with PAH showed significantly decreased levels of sTWEAK [median 314?pg/ml (interquartile range...

British Library Electronic Table of Contents (United Kingdom)

Two types of representative nanometer materials, i.e., fibroid nanometer attapulgite and approximate spherical ultrafine diamond, were selected as fillers of polytetrafluoroethylene (PTFE) to study the mechanism of the wear-reducing actions of the fillers in PTFE composites. The friction and wear tests were performed on a block-on-ring wear tester under dry sliding conditions. Differential scanning calorimetry (DSC) was used to investigate material microstructure and to examine modes of failure. No significant change in coefficient of friction was found, but the wear rate of PTFE composites was orders of magnitude less than that of pure PTFE. DSC analysis revealed that nanometer attapulgite and ultrafine diamond played a heterogeneous nucleation role in PTFE matrix and consequently resulte...

International Nuclear Information System (INIS)

A large portion of the work performed at nuclear power plants follows standardized flow paths. For example, although components on which the maintenance crew works differ from one assignment to the next, all assignments basically follow the same process: requesting, reviewing, planning, scheduling, executing, testing, and documenting the work. In general, the term open-quotes work processclose quotes is used to refer to a standardized sequence of tasks designed within the operational environment of an organization to achieve a specific goal. The predictable nature of work processes suggests that a systematic analysis can be conducted to identify the desirable design of the process and to develop performance measures with respect to the strengths and weaknesses in the process. Furthermore, because of the close relationship of the work process to plant performance and plant safety, it is believed that such an analysis will facilitate the inclusion of organizational ...

British Library Electronic Table of Contents (United Kingdom)

This project is about the simulation design of an engine control unit (ECU) for an Otto cycle engine with electronic fuel injection (EFI). The simulation includes a model for the ECU as well as physical parameters of the engine, which allows closed-loop control and monitoring of various systems.This simulation has been realized using Simulink and Stateflow, which are components of Mathworks' MATLAB software.The program allows control of various parameters of the ECU, as well as the simulation of failures to verify that the designed ECU is fault-tolerant and can control the engine using an open loop control. The main function the ECU provides is fuel metering.Subsequently, this program could be used as a tool to quickly develop and test models of ECU in order to control an engine in laborat...

International Nuclear Information System (INIS)

Daya Bay Nuclear Power Plant is put into commercial operation in 1994 Until 1996, there are 368 human error events in operating and maintenance area, occupying 39% of total events. These events occurred mainly in the processes of maintenance, test equipment isolation and system on-line, in particular in refuelling and maintenance. The author analyses root causes for human errorievents, which are mainly operator omission or error procedure deficiency; procedure not followed; lack of training; communication failures; work management inadequacy. The protective measures and treatment principle for human error events are also discussed, and several examples applying them are given. Finally, it is put forward that key to prevent human error event lies in the coordination and management, person in charge of work, and good work habits of staffs.

Science.gov (United States)

A comparative analysis between conventional passive twin tube dampers and skyhook-controlled magneto-rheological fluid (MRF) dampers for motorcycle front suspensions is provided, based on single axis testing in a damper test rig and suspension performance testing in road trials. Performance motorcycles, while boasting extremely light suspension components and competition-ready performance, have an inherent weakness in comfort, as the suspension systems are designed primarily for racing purposes. Front suspension acceleration and shock loading transmit directly through the front suspension triple clamp into the rider's arms and shoulders, causing rapid fatigue in shoulder muscles. Magneto-rheological fluid dampers and skyhook control systems offer an alternative to conventional sport motorcycle suspensions - both performance and comfort can be combined in the same package. Prototype MRF dampers designed ...

Energy Technology Data Exchange (ETDEWEB)

A gamma-ray spectrometer (GRS) has been built and delivered to the Mercury MESSENGER spacecraft which launched on August 3, 2004, from Cape Canaveral, Florida. The GRS, a part of seven scientific instruments on board MESSENGER, is based on a coaxial high-purity germanium detector. Gamma-ray detectors based on germanium have the advantage of providing excellent energy resolution, which is critical to achieving the science goals of the mission. However, germanium has the disadvantage that it must operate at cryogenic temperatures (typically {approx}80 K). This requirement is easy to satisfy in the laboratory but difficult near Mercury, which has an extremely hot thermal radiation environment. To cool the detector, a Stirling cycle mechanical cooler is employed. In addition, radiation and conduction techniques a are used to reduce the GRS heat load. Before delivering the flight sensor, a complete thermal prototype was built and tested. The results ...

Energy Technology Data Exchange (ETDEWEB)

When the foundations of the building are designed and worked, the prediction calculation of immediate settlement of the building exercised practically is to calculate assuming the earth is a linear elastic body, but the actual stress-strain relationship of the earth is nonlinear and rigidity of the earth becomes lower as strain (or stress) increases. Hence in order to grasp the actual settling behavior of the earth, it is necessary to elucidate the nonlinear relationship between stress and strain. In this article, a prediction method of building settlement is introduced which uses an analytical technique of the multi-layered earth by the linear elasticity theory and takes into consideration strain dependency of rigidity of the earth. Part of the conclusion is as follows which has been obtained by studying the settling behaviors observed in examples of vertical loading tests of the pile foundations and the elasto-plastic settlement analytical ...

Energy Technology Data Exchange (ETDEWEB)

This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory ...

Energy Technology Data Exchange (ETDEWEB)

The conceptual design of an ohmically heated, reversed-field pinch (RFP) operating at /approximately/5-MW/m/sup 2/ steady-state DT fusion neutron wall loading and /approximately/124-MW total fusion power is presented. These results are useful in projecting the development of a cost effective, low input power (/approximately/206 MW) source of DT neutrons for large-volume (/approximately/10 m/sup 3/), high-fluence (3.4 MW yr/m/sup 2/) fusion nuclear materials and technology testing. 19 refs., 15 figs., 9 tabs.

Energy Technology Data Exchange (ETDEWEB)

The power industry is moving toward the use of high-voltage transmission lines on tall, flexible towers. These towers are designed for heavier loadings than were previous towers, but the secondary effects of tower displacement tend to be ignored in the present day tower analysis. This paper examines the secondary effects from the large displacement of flexible towers, reviews the secondary stresses arising from joint rigidity and member continuity, and examines the reliability of tower strength predicted by the ASCE design guidelines. More realistic tower test acceptance criteria and a more reliable tower design methodology are suggested.

Science.gov (United States)

An experiment of a plasma torch on a production foundry cupola is reported. The test runs were conducted on a hot blast cupola, the blast temperature in the absence of plasma being 400 C. With the torch, the temperature of the blast was increased to 1000 C. The experiment was conducted for the manufacture of car engines with a 2.5 MW transportable plasma system. The cupola was boosted with a 4 MW torch and results included an increase in production of 45 percent, a decrease in coke rate and no more new iron in the loads. The plasma torch and hot air cupola furnace are described.

Energy Technology Data Exchange (ETDEWEB)

The LANL 2.5-cell, normal-conducting radio-frequency (NCRF) injector has been fabricated. We present initial results of low-power RF measurements (cavity Q, cavity field map, coupling beta, etc.) of the NCRF injector. The measured cavity Q and relative fields are found to be in good agreement with the design calculations and earlier measurements of Glidcop properties. However, the coupling beta of the ridge-loaded waveguides is found to be significantly higher than the design point. The impact of these low-power measurement results on the planned high-power RF and electron beam tests will be discussed.

Energy Technology Data Exchange (ETDEWEB)

This Workpackage Report describes the introduction of fatigue cracks in bolts with ISO-metric threads M5x0.8, M8x1.0, M12x1.25 made from the materials Ti 6Al 4V, A-286 and INCONEL 718. Introdued cracks are verified by destructive testing. Results of the NDI of these bolts performed with special eddy current probes are reported. The detectability of cracks with a {>=} 0.65 and a/2c {approx equal} 0.3 located in the thread ground perpendicular to the load axis is demonstrated. (orig.).

International Nuclear Information System (INIS)

The purpose of this work was to develop and evaluate a method of locating breached fuel within the Fast Flux Test Facility (FFTF) reactor based on the relative response of the delayed neutron monitors (DNM) located on each of the three primary sodium cooling loops. The primary method of location is the use of tag gas containing unique ratios of the noble gases xenon and krypton. Although the tag gas system works quite well, it is relatively expensive because of the costs of preparing and loading the gas into each fuel pin. Triangulation of DNM signals could potentially decrease tag gas costs while maintaining overall location reliability.

International Nuclear Information System (INIS)

The single specimen unloading compliance technique has become the preferred method for evaluating J-integrals. It involves data acquisition and analysis using a computer. This paper describes in detail the development of a simple experimental system and related software that can be used in a laboratory equipped with a microcomputer and with access to a minicomputer. The effects of loading rate, test temperature, specimen geometry and material composition can be readily evaluated using this system. The results on a pressure vessel steel and an #alpha#-#beta# titanium alloy are discussed in Part II. (author).

International Nuclear Information System (INIS)

Due to thermal gradients and load changes steam-turbine casings suffer combined creep-fatigue loading. Creep and fatigue portions depend on service conditions. Special interest is focused on the behaviour of creep-fatigue cracks, originated from potential defects due to construction and manufacturing weldments, on residual lifetime assessment. The project deals with the crack-growth behaviour at 530deg C and r.t. of welded and unwelded heat-resistant cast steels: 1% CrMoV-cast (GS-17 CrMoV 5 11, two melts: low and high V-content) and 12% CrMoV-cast (G-X 22 CrMoV 12 1). The crack planes of CT-specimens investigated, taken from manual arc-welded plates, were situated in the heat-affected zone (HAZ). The fatigue, creep and combined creep-fatigue crack-growth behaviour was investigated by means of low-frequency (0.5 and 0.05 Hz) tests, holding-time (20 min) tests and constant load ...

Energy Technology Data Exchange (ETDEWEB)

This paper discusses how to overcome failures and pitfalls in software configuration management. (LSP)

International Nuclear Information System (INIS)

A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author).

Energy Technology Data Exchange (ETDEWEB)

This report documents the investigation regarding the failure of CPVC piping that was used to connect a solar hot water system to standard plumbing in a home. Details of the failure are described along with numerous pictures and diagrams. A potential failure mechanism is described and recommendations are outlined to prevent such a failure.

British Library Electronic Table of Contents (United Kingdom)

A viscoelastically prestressed polymeric matrix composite (VPPMC) is produced by applying tension to polymeric fibres, the tensile load being released prior to moulding the fibres into a matrix. Following matrix solidification, compressive stresses imparted by the viscoelastically strained fibres improve composite tensile, flexural and impact properties. This study focuses on the potential for useful life and impact protection capability by performing Charpy impact tests on nylon 6,6 fibre-polyester resin samples subjected to accelerated ageing. Prior to testing, time-temperature superposition principles were used, the samples being aged by heating to 60degreeC for periods representing a 10-fold increase over previous work. The results demonstrated no deterioration in impact performance ov...

British Library Electronic Table of Contents (United Kingdom)

Two analytical methods were proposed in this research, coupled electro-thermal finite element (FE) analysis and thermal-mechanical FE analysis, to analyze the mechanical behavior of bonding wire of power module under cyclic power loads, and the International Electrotechnical Commission standard is adopted in conducting a power cycling test. The exterior temperature distribution was measured by an infrared thermometer. Moreover, the junction temperature is calculated from the given thermal impedance of the semiconductor chip, chip power loss, and case temperature. Subsequently, the simulated temperature distribution via electro-thermal FE analysis is compared with experimental results to validate the methodology used in the aforementioned analysis. The analysis shows compressive stress at t...

Energy Technology Data Exchange (ETDEWEB)

The low-cycle fatigue behaviour of copper and a-brass CuZn30 was investigated in uniaxial and biaxial tests. Planar biaxial fatigue tests were carried out using cruciform samples with proportional stain paths with and without phase shift between the two axes. Microcharacterisation was performed by electron microscopy as well as by high-resolution X-ray line profile analysis. The biaxial cyclic stress-strain curves show good agreement with the uniaxial ones using the von Mises equivalent strain hypothesis. The dislocation densities and microhardness values of the biaxial case, however, show significantly lower values compared to the uniaxial case at equivalent von Mises stresses.

Energy Technology Data Exchange (ETDEWEB)

TiB{sub 2} appears to be a promising material for the wear protection in various tribological systems, e.g. the diecasting of Al. This study focuses on the development of titanium boride coatings deposited by PACVD, a deposition method which is most suitable for the coating of substrates with complex shapes. All layers analysed are very smooth and exhibit a quasi-amorphous fracture surface. XRD and TEM analysis indicate a nanocrystalline structure with grain sizes in the order of 2 nm. The diffraction patterns can well be correlated to titanium diboride. WDS reveals an over stoichiometric B/Ti ratio. The layer hardness reaches the value of 33 GPa and the critical load in scratch tests rises to 35 N. Neither 100Cr6 nor Al as a counterpart in pin-on-disk tests leads to wear of the coating. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The Fast Flux Test Facility (FFTF) core loading during its ninth operating cycle was significantly different from that of previous cycles because of the presence of the Core Demonstration Experiment (CDE). The CDE consists of a number of axially blanketed fuel assemblies and internal blankets prototypic of advanced oxide cores in Liquid Metal Reactors (LMR). In preparation for the Cycle 9 reload design effort, a careful assessment of control rod worth and reactivity calculations for Cycles 1 through 8 was made. The goal of this study was to establish calculational biases and reduce uncertainties factored into the reload design calculations. These analyses helped assure that the operational objectives for Cycle 9 were met.

International Nuclear Information System (INIS)

Extensive investigations and detailed analysis of the failure reason of 9DVN002ZV fan in Daya Bay Nuclear Power Station showed that the fan destroy was caused by the failure of non-drive end bear. The direct cause of this bearing' failure was its improper assembly caused by improper maintenance procedure, and the root cause was too small internal radial clearance after mounting. The factor affecting bearing internal radial clearance, the relationship between clearance and operating life time and fan failure process were discussed. (authors)

Energy Technology Data Exchange (ETDEWEB)

One of the main requirements to use Be as a candidate for plasma facing component in ITER is providing a reliable joint between Be and Cu-alloy heat sink structure. In this work authors present the results of recent activity on this way. To create Be/CuCrZr joints the unique fast e-beam brazing technology was developed in Russia. The numbers of Be/CuCrZr mock-ups were manufactured in Efremov Institute by fast e-beam brazing using Cu-Sn-In-Ni brazing alloy. These mock-ups were tested by Sandia Laboratory at the EBTS electron beam facility. The goals of the tests were to define the allowable dimensions of the armour tiles for the heat loads of more than 10 MW/m{sup 2}, to find the limit of bond strength for the Be/CuCrZr joint and response to heat loads and to estimate the life time of the brazed tiles by thermo-cyclic testing. The screening and thermal fatigue results are presented. ...

Science.gov (United States)

Not Available

Science.gov (United States)

...2010-07-01 false Loading and haulage equipment; inspection and maintenance... § 77.1606 Loading and haulage equipment; inspection and maintenance. (a) Mobile loading and haulage equipment shall be inspected by a...

Science.gov (United States)

...position to receive material. (2) Self-loading haulage equipment used as a loading machine. In working places in which self-loading haulage equipment is operated to load material, the areas which...

Energy Technology Data Exchange (ETDEWEB)

There is renewed interest in the development of natural gas vehicles in response to the challenge to reduce urban air pollution and consumption of petroleum. The natural gas/diesel dual fuel engine is one way to apply natural gas to the conventional diesel engine. Dual fuel engines operating on natural gas and diesel emit less nitrogen oxides, and less carbon soot to the air compared to conventional diesel engines. The problem is that at light loads, fuel efficiency is reduced and emissions of hydrocarbons and carbon monoxide are increased. This thesis focused on control methods for emissions of hydrocarbons and carbon monoxide in the dual fuel engine at light loads. This was done by developing a reverse flow catalytic converter to complement dual fuel engine exhaust characteristics. Experimental measurements and numerical simulations of reverse flow catalytic converters were conducted. Reverse flow creates a high reactor temperature even when ...

Energy Technology Data Exchange (ETDEWEB)

This fourteenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period November 1, 1990 to January 31, 1991. Testing of the High Pressure Cooling Subsystem electrical isolator was completed. The PEEK material successfully passed the high temperature, high pressure duration tests (50 hours). The Combustion Subsystem drawings were CADAM released. The procurement process is in progress. An equipment specification and RFP were prepared for the new Low Pressure Cooling System (LPCS) and released for quotation. Work has been conducted on confirmation tests leading to final gas-side designs and studies to assist in channel fabrication.The final cathode gas-side design and the proposed gas-side designs of the anode and sidewall are presented. Anode confirmation tests and related analyses of anode wear mechanisms used in the selection of the ...

International Nuclear Information System (INIS)

Mixed carbide fueled driver assembly experiments will be tested in FFTF fuel driver positions as part of the National Advanced Fuel Program. The design of the experiment flow ducts must assure conformance to FFTF functional requirements in addition to service as a test vehicle for the carbide fuel irradiations. Test goals of damage fluence burnup, and fluence to burnup ratio exceed those of the standard oxide fueled drivers. As a consequence, the 20% cold worked type 316 stainless steel material of construction will experience significant irradiation induced creep and swelling. Additionally, the flow duct design must withstand the enhanced thermal transients produced by the action of carbide fuel during reactor scrams. A major FFTF functional requirement is that adjacent flow ducts do not touch each other except at the load pads. This requires a realistic analysis of the creep and swelling deformation ...

Energy Technology Data Exchange (ETDEWEB)

This paper reports the result obtained during fiscal 1994 on a demonstration research on photovoltaic power generating systems. Solar cells with an output of 750 kW, storage battery facilities with an output of 3,058 kWh, three DC-AC converters with a rating of 250 kW, and a diesel generator with an output of 300 kW having been installed up to the previous fiscal year were combined to perform comprehensive adjustments and tests such as battery charge/discharge tests and AC parallel operation tests. The battery charge/discharge tests revealed that the 10 hour rate discharge capacity meets the specifications, and the batteries are free of deterioration after a demonstration operation of about 4.5 months. Difference between the power generation record and the planned value is thought due to the following reasons: the array output data in a power line connected system come about 90% of the simulation result ...

Energy Technology Data Exchange (ETDEWEB)

Aiming to realize ball bearings operable in a vacuum and under high temperature, silicon nitride (Si3N4) ceramic ball bearings were tested. The tested ball bearings were angular contact ball bearings composed of silicon nitride with sputtered molybdenum disulfide coating using a retainer of hot-pressed self-lubricating composite material. The time variation of the frictional torque was examined for the operations under the conditions at 500{degree}C in a vacuum at a rotational speed of 600 rpm and 50N thrust load for 5{times}10{sup 7}revolutions (1400 hours) and for 1.5{times}10{sup 8}revolutions (4200 hours). Excellent tribological performance was obtained. The ball bearings are lubricated with the molybdenum disulfide film at the initial stage of the operation and with a transfer film formed from the retainer material to the balls. In a test at 650{degree}C, low and stable frictional torque was ...

Energy Technology Data Exchange (ETDEWEB)

An experimental and computational study was undertaken to estimate the effects of pipe rupture and induced pipe whip impact on surround structures considered either as rigid or deformative such as concrete slabs. This program included sixteen tests using 3 inch schedule 80 (or 10) pipes made of carbon steel similar to A106 grade B. The study consisted of tests on rigid target and on concrete slab. The investigation of whip phase and impact phase was done separately for each test. For pipe impact on rigid targets, the impact forces are found to be directly related to the crush strength of the pipe and the general pipe deformation following the impact. For pipe impact on concrete slabs, the response of the target to the pipe impact needs to take into account the local effect such as penetration and localized damage on the slab. The test matrix covered a broad range of geometric parameters. It provides a ...

Energy Technology Data Exchange (ETDEWEB)

Korea Advanced Energy Research Institute (KAERI) started a research project to develop the PHWR (CANDU) nuclear fuel fabrication technology in 1981. Based on the results of the intensive developmental work, several prototype fuel bundles were fabricated and tested in the Hot Test Loop at KAERI continuously in 1983 and 1984. After that, irradiation test and post-irradiation examination were carried out for two KAERI-made fuel bundles at Chalk River Nuclear Laboratories in Canada in 1984. Since the results of in-pile and out-of-pile tests with prototype fuel bundles proved to be satisfactory, 48 additional fuel bundles were loaded in Wolsung reactor (CANDU) in 1984 and 1985, and all of them were discharged without a defect after excellent performance in the power reactor. In 1985, the Korean government decided that KAERI supplies all the fuel necessary for the Wolsung reactor. For the ...

Energy Technology Data Exchange (ETDEWEB)

The technology for performance testing and improvement of materials which are durable at space environment is a military related technology and veiled and securely regulated in advanced countries such as US and Russia. This core technology cannot be easily transferred to other country too. Therefore, this technology is the most fundamental and necessary research area for the successful establishment of space environment system. Since the task for evaluating the effects of space materials and components by space radiation plays important role in satellite lifetime extension and running failure percentage decrease, it is necessary to establish simulated space radiation facility and systematic testing procedure. This report has dealt with the status of the technology to enable the simulation of space environment effects, including the effect of space radiation on space materials. This information such as the fundamental ...