Energy Technology Data Exchange (ETDEWEB)

Recent advances in elastic-plastic fracture mechanics have made it possible to assess the stability of cracks in ductile piping systems. These technological developments have been used by Ontario Hydro as the nucleus of an approach for demonstrating that CANDU primary heat transport piping systems will not break catastrophically; at worst they would leak at a detectable rate. This leak-before-break approach has been taken on the Darlington nuclear generating station as a design stage alternative to the provision of pipe whip restraints on large diameter, primary heat transport system piping. Positive conclusions reached via this approach are considered sufficient to exclude the requirement to provide protective devices, such as pipe whip restraints. In arriving at the proposed leak-before-break approach a review of current and proposed leak-before-break licensing positions of other ...

Energy Technology Data Exchange (ETDEWEB)

Upon request by the Science and Technology Agency of Japanese Government, the Japan Atomic Energy Research Institute has conducted Piping Reliability Test Program to demonstrate the safety and reliability of light water reactor primary pipings. In this report, the results of the program are summarized. In the test program, pipe fatigue tests, Leak-Before-Break (LBB) verification tests and pipe rupture tests were carried out to examine the integrity of pipings, to verify the LBB concept and to demonstrate the effectiveness of the protective measures against jet impingement and pipe whip under pipe rupture event, respectively. In the pipe fatigue tests, a procedure to predict the fatigue crack growth was developed and the integrity of piping during plant service life was ...

International Nuclear Information System (INIS)

Dynamic pipe impact tests were performed in order to determine the impact conditions for which a 2 inch Schedule 80 carbon steel target pipe would not be broken if it were impacted during a pipe whip event created by a postulated break of an adjacent larger parallel pipe. Such pipe/pipe impact scenarios are of special interest for the feeder pipes of a CANDU reactor because the large number of closely spaced parallel feeder pipes that carry coolant between large primary system pipes and individual fuel channels in the reactor core makes it impractical to consider providing feeder pipe whip restraints. The testing which was performed involved simulating the behaviour of 3 inch and larger whipping pipes in order to study their impact with 2 inch target pipes ...

International Nuclear Information System (INIS)

To evaluate safety of horizontal steam generator used in passive safety system, it is needed to make clear flooding characteristics in U bend pipe. In this study, two-phase flow experiment in a horizontal U bend pipe was carried out to make clear the influence of the length of horizontal pipe and the radius of U bend. Flooding in the U bend pipe was observed in the condition of lower gas or liquid volumetric flux than that in the horizontal pipe or the vertical pipe. Flooding and carry-up in the U bend pipe is hardly change with increasing the length between the water inlet and the U bend, but greatly related with the length from the water inlet to the lower tank and the shape of the U bend inlet. (author).

Energy Technology Data Exchange (ETDEWEB)

Conference paper regarding research in freeze-protection methods that could extend market acceptance for passive solar domestic water heating systems in more northern climates if the U.S.

Energy Technology Data Exchange (ETDEWEB)

Conference paper regarding research in the use of freeze prevention for passive solar domestic water heating systems.

International Nuclear Information System (INIS)

Imatran Voima Oy , (IVO) operates two Russian designed nuclear power plants of type VVER440/213. Unit 1 has been operating since 1977 and unit 2 since 1981. First damage of feed water distribution (FWD) pipes was observed in 1989. In closer examinations FWD-pipe T-connection and distribution nozzles suffered from severe erosion corrosion damage. Similar damages have been found also in other VVER-440 type NPPs. In 1994 the first FWD-pipe was replaced by a new design mounted over the tube bundle instead of the old FWD-pipe, which was located inside the tube bundle. The purpose of this paper is to describe the new FWD-pipe and discuss its effects on the steam generator chemistry. (author)

Energy Technology Data Exchange (ETDEWEB)

This standard addresses the design bases for light water reactor, nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip, jet impingement, pressurization of compartments outside containment, environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.

Energy Technology Data Exchange (ETDEWEB)

The design of high level radioactive waste (HLW) repositories in deep geological media in which bentonite clay is proposed as a sealing material leads to the need of further studying the behaviour of highly compacted expansive soils when subjected to mechanical, hydraulic and thermal changes. Laboratory tests may help to understand the processes that take place in the clay barrier under simple and controlled conditions and to develop the governing equations. The laboratory tests enable to isolate the different processes, making their interpretation easier, and provide with fundamental data concerning the parameters to be used in the models. The extremely low permeability of these materials, their avidity for water (high suction) and their high swelling capacity make necessary the modification of the conventional laboratory techniques and procedures to determine basic physical parameters. The main hydraulic properties of the barrier to be ...

Energy Technology Data Exchange (ETDEWEB)

HANARO fuel test loop will be equipped in HANARO to obtain the development betterment of advanced fuel and materials through the irradiation test. The object of this study is to evaluate the structural integrity of FTL in-pool piping by investigating a dynamic analysis of the loop containing a postulated rupture section. The method to perform the dynamic analysis and structural integrity evaluation caused by the pipe whip in water environment can be a reference for a similar structural integrity evaluation. (author). 7 refs., 39 tabs., 34 figs.

Science.gov (United States)

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

International Nuclear Information System (INIS)

The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a function of temperature ...

International Nuclear Information System (INIS)

Despite successful reduction of the general lead exposure, this heavy metal is still a matter of public concern due to the fact that associations with intellectual impairment or delayed puberty are found to correlate with very low lead blood concentrations. Lead in tap water is still an important contribution to lead exposure which may cause health risk for infants. Therefore, lead pipes should be completely sanitated by exchange against pipes made from more healthy materials. (orig.)

International Nuclear Information System (INIS)

Once containment recirculation pumps are activated and emergency core cooling (ECC) flow is supplied from the recirculation sump during loss of coolant accident (LOCA), various insulations and coatings on a pipe, equipments and structures damaged by LOCA break jet as well as additional debris sources are transported to recirculation sump screen by the break flow and containment spray flow drainage. This debris may result in loss of net pressure suction head (NPSH) of the recirculation pumps, and have a threat to long term cooling and containment heat removal capacity. In this case, flow patterns of containment pool are important to confirm behaviors of debris transport for predicting various flow paths to the recirculation sump screen. In this paper, models using commercial computational fluid dynamics (CFD) software CFX are developed for containment pool simulation during recirculation mode. The specific plant used for this analysis is CANDU ...

Science.gov (United States)

Internal hydrological processes in suburban watersheds and their effects on water quality warrant investigation. Instrument clusters (throughfall collectors, suction lysimeters, monitoring wells, and shallow and deep piezometers) were installed at several locations within three small (50 - 70 ha) watersheds (one forested, two with different degrees of suburban development) in the Croton Watershed, southeastern New York. Biweekly and storm samples were analyzed for base cations, selected anions, and DOC over a one-year period. The topographic index (TI) quantified landscape position; flowpath analyses determined degree of development at each cluster, using % impervious cover as the metric. Water quality degradation was observed in sites with medium and high TI values; no such effect was observed along the ridges, i.e., low TI values. At medium TI values, areas with more than 5% impervious had degraded ...

Energy Technology Data Exchange (ETDEWEB)

This thesis presents an experimental study performed on compacted loose and natural dense expansive soils using osmotic odometers. Several successive cycles were applied under three different low constant vertical net stresses. The loose soil presents a significant shrinkage accumulation while the dense one produces the swelling accumulation during the suction cycles. The suction cycles induced an equilibrium stage which indicates an elastic behaviour of the samples. At the end of suction cycles, a loading/unloading test was performed at the constant suctions for both materials. The mechanical parameters, i.e. the virgin compression index lambda(s), the apparent pre-consolidation stress p0(s) and the elastic compression index values lambda are completely dependent on the followed stress paths. The whole experimental results made it possible to define the yielding surfaces: suction ...

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.

International Nuclear Information System (INIS)

Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent the FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC have conducted a study for developing systematic FAC management technology for secondary side piping of all Korean nuclear power plants. As a part of the study, FAC analyses were performed using the CHECWORKS code. The analysis results were used to select components for inspection and to determine inspection intervals on each nuclear power plant. This paper describes the introduction of the FAC analysis method and the wall thinning trend analysis results by reactor type, system, and water treatment amine. This paper also represents the ...

Energy Technology Data Exchange (ETDEWEB)

THMs are disinfection by-products (DBPs) generated during water chlorination. Concentration of individual and total THMs, depends on treatment process and THMs precursors level. ATLL water utility has two DWTP (Llobregar and Ter) that produce and supply drinking water to Barcelona and regional area. This work studies the levels of THMs along the ATLL distribution system (450 km). Although, no differences were observed along water pipes system, changes of water resource and mix procedures were related. (Author) 12 refs.

International Nuclear Information System (INIS)

Special T-shaped feedwater distribution pipes were installed in steam generators at the Loviisa (Finland) and Rovno (Russia) nuclear power plants. The new shape was tested in an extensive testing programme. Since the tubes frequently suffer from corrosion damage, large-scale water hammer experiments were performed on a model facility in 1996. The main objectives of the water hammer experiments were to find out the prevailing parameters leading to water hammers, as well as the sensitivity of hammering to boundary conditions. A water hammer may occur when the mass flow rate into the steam generator exceeds 6 kg/s and the temperature difference between steam generator and feedwater exceeds 100 degC. Visual experiments and stress analyses of the pipe were also carried out. The weakest part, the T-joint, may hold against such water hammers only ...

Energy Technology Data Exchange (ETDEWEB)

The WIT telemanagement system simply, reliably and efficient by makes available to us in real time processed, ordered and managed data. Such information has been used to optimise the performance of the drinking water distribution networks on a number of housing estates. This has led to major saving in consumption and on equipment maintenance, thereby improving customer service and obtaining a more rational use of piped water. (Author)

Energy Technology Data Exchange (ETDEWEB)

The requirements to design nuclear power plants for the effects of an instantaneous double-ended guillotine break (DEGB) of the reactor coolant piping have led to excessive design costs, interference with normal plant operation and maintenance, and unnecessary radiation exposure of plant maintenance personnel. This report describes an aspect of the NRC/Lawrence Livermore National laboratory-sponsored research program aimed at investigating whether the probability of DEGB in Reactor Coolant Loop Piping of nuclear power plants is acceptably small such that the requirements to design for the DEGB effects (e.g., provision of pipe whip restraints) may be removed. This study estimates the probability of indirect DEGB in Reactor Coolant piping as a consequence of seismic-induced structural failures within the containment of the GE supplied boiling water reactor at the Brunswick nuclear ...

Energy Technology Data Exchange (ETDEWEB)

Ejector refrigeration systems are usually designed to utilize low grade energy for driving the cycle. They also have low maintenance cost because they operate without a compressor. Mainly, the ejector performance directly affects the refrigerating performance. Therefore, an investigation on the characteristics and an efficient design of the ejector are important to improve ejector refrigeration systems. In this study, the computational fluid dynamics (CFD) code, FLUENT, is employed to predict the flow phenomena and performance of CPM and CMA steam ejectors. The ejector refrigeration system, using water as the working fluid, is operated at 120-140 C boiler temperature and 5-15 C evaporator temperature. CFD can predict ejector performance very well and reveal the effect of operating conditions on an effective area that is directly related to its performance. Besides, it is found that the flow pattern does not depend much on the suction zone ...

Energy Technology Data Exchange (ETDEWEB)

About ten years ago microbiologically influenced corrosion manifested on stainless steel pipes used with river water for cooling a chemical plant. The pipe material was similar to Type 316 L. After only six weeks of operation pinhole leaks occurred nearly simultaneously at several welded joints of the pipe. The material degradation was simulated in laboratory and field corrosion tests. Microbiologically influenced corrosion failures also appeared on the pipes of a tubular heat exchanger of duplex steel Type 31803 and on carbon and stainless steel pipes in industrial waste water purification plants after these plants had been modernized with a biological purification unit. The basics of microbiologically influenced corrosion phenomena and typical corrosion failures of pipes will be described. (orig.) [German] Vor etwa ...

International Nuclear Information System (INIS)

A safety analysis code, named as SPACE, for a pressurized water reactor is under development to obtain a licensing to be used for the PWR design and to hold entire proprietary rights. The task of KAERI is to develop the physical models and correlations which are required to solve the field equations. It can be divided into four parts; i) flow regime determination, ii) wall heat transfer, iii) wall and interfacial friction, iv) interfacial heat and mass transfer. This paper will describe the process to develop the models for the two-phase flow regime maps in the horizontal and vertical pipes.

Energy Technology Data Exchange (ETDEWEB)

The objective of the present study is to reveal thermal characteristic of microcapsulated lauric acid slurry in circular pipe. Test were performed with microcapsulated lauric acid slurry in a heating test section with a constant heat flux boundary condition. Local Nusselt number and the effective thermal capacity were measured. As the size of microcapsulated lauric acid were increased, local Nusselt number of microcapsulated lauric acid slurry were increased. The effective thermal capacity of microcapsulated lauric acid slurry was 0.5 times than it of water.

Science.gov (United States)

The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas-oiland water possibly along wi...

Energy Technology Data Exchange (ETDEWEB)

During LOCA (Loss of Coolant Accident) in design bases accident (DBA), emergency core coolant supplements form a recirculation sump and cooled core and containment. When the double ended guillotine Break (DEGB) at the hot leg near steam generator, due to the jet impingement discharge flow, the debris could be potentially generated at pipe or wall nearby steam generator and be transported to the recirculation sump. Therefore, the debris, such as insulations and paint chips, could be accumulated and be clogged in the recirculation sump screen. If debris is blocked the sump strainer, the pressure drop is increased at the screen so as to increase the pressure loss of ECCS (Emergency Core Cooling System) pump NPSH (Net positive suction head). It is potentially influenced to decrease the long-term cooling capability of the recirculation sump. The recirculation sump screen clogging accident has happened in BWR of USA and Sweden. Considering the ...

International Nuclear Information System (INIS)

A theoretical analysis of two-dimensional unsteady flow in a porous medium bounded by a horizontal wall is presented as a perturbation on a basic flow. It is assumed that the perturbation is occasioned by a sudden suction at the wall. Even for a highly permeable medium the characteristic Reynolds number in porous media flow is usually small and asymptotic solutions are developed by the Laplace transform technique. It is observed that the perturbed shear stress at the wall decays exponentially with time. (author). 5 refs.

Energy Technology Data Exchange (ETDEWEB)

This analysis defines and evaluates the surface water supply system from the existing J-13 well to the North Portal. This system includes the pipe running from J-13 to a proposed Booster Pump Station at the intersection of H Road and the North Portal access road. Contained herein is an analysis of the proposed Booster Pump Station with a brief description of the system that could be installed to the South Portal and the optional shaft. The tanks that supply the water to the North Portal are sized, and the supply system to the North Portal facilities and up to Topopah Spring North Ramp is defined.

Energy Technology Data Exchange (ETDEWEB)

A 4-loop Pressurised Water Reactor (PWR) primary coolant system has been analysed for the postulated Loss of Coolant Accident (LOCA) event in order to derive peak dynamic loads for qualifying the design of equipment supports and pipe whip restraints. Pipe whip restraints as well as pipe and equipment supports are nonlinear by nature because of the presence of gaps and the different directional stiffnesses arising from snubber, steelwork and geometric and material interaction at the concrete to steel embedment. The different structural idealisations for the supports and restraints have an influence on the dynamic response of the structure. In the first of the two part paper a range of idealisation models for the Steam Generator and Reactor Coolant Pump vertical columns ranging from elastic stiffnesses to bilinear stiffnesses with or without preload were examined. Due to both structural and loading ...

International Nuclear Information System (INIS)

Object: To suppress a quantity of impurities in a coolant fed into a reactor vessel. Structure: The concentration of oxygen in a coolant flowing from a condensation desalting instrument into a feed and condensation piping is measured by an oxygen-concentration detector to feed its signal to an adjusting instrument. A degree of opening of an oxygen flow control valve to maintain the concentration of oxygen in the cooling water flowing within the pipe in the range from about 10 to about 200 ppb. Also, the concentration of oxygen in the cooling water fed to the desalting instrument is maintained at a level less than 2 ppb. Thereby, the total amount of iron flown into the vessel can be suppressed to a fine amount such as less than about 1 ppb. (Kawakami, Y.).

Energy Technology Data Exchange (ETDEWEB)

No information on steam/water two-phase flow behavior in large diameter pipes (10 inch or larger) at elevated pressures is available in the open literature. However, there are many applications, in the nuclear, chemical and petroleum industries among others where two-phase flows in large diameter pipes at elevated pressures and temperatures are encountered routinely or under accident scenarios. Experimental data on steam-water two-phase flow in a large diameter (20 inch, 50.08 cm I.D.) vertical pipe at elevated pressures and temperatures (2.8 MPa/230 C--6.4 MPa/280 C) have been obtained. Void fraction, two-phase mass flux, phase and velocity distributions as well as pressure drop along the test pipe have been measured using the Ontario Hydro Technologies (OHT) Pump Test Loop. The void fraction distributions were found to be axially symmetric and nearly flat over ...

Energy Technology Data Exchange (ETDEWEB)

Studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington have focused on developing and evaluating the reliability of nondestructive testing (NDT) approaches for coarse-grained stainless steel reactor components. The objective of this work is to provide information to the United States Nuclear Regulatory Commission (NRC) on the utility, effectiveness and limitation of NDT techniques as related to inservice testing of primary system piping components in pressurized water reactors. We examined cast stainless steel pipe specimens containing thermal and mechanical fatigue cracks located close to the weld roots and having inner and outer diameter surface geometrical conditions that simulate several water reactor primary piping configurations. In addition, segments of vintage centrifugally cast piping were examined to characterize ...

International Nuclear Information System (INIS)

The humidification dehumidification desalination process is viewed as a promising technique for small capacity production plants. The process has several attractive features, which include operation at low temperature, ability to utilize sustainable energy sources, i.e. solar and geothermal, and requirements of low technology level. This paper evaluates the characteristics of the humidification dehumidification desalination process as a function of operating conditions. A small capacity experimental system is used to evaluate the process characteristics as a function of the flow rate of the water and air streams, the temperature of the water stream and the temperature of the cooling water stream. The experimental system includes a packed humidification column, a double pipe glass condenser, a constant temperature water circulation tank and a chiller for cooling ...

Energy Technology Data Exchange (ETDEWEB)

This book presents the papers given at a conference on two-phase flow. Topics considered at the conference included the thermal hydraulics of a feedwater pipe breakage, pressure losses, measurement of void fraction in a rod bundle, laminar filmwise condensation, natural circulation, flow models, bubble dynamics, cavitation, water hammer, and heat transfer augmentation.

Energy Technology Data Exchange (ETDEWEB)

The effect of longer ice-free periods on the seasonal variation and total annual values of phytoplankton primary production was considered along with the efficiency and productivity of the phytoplankton communities at different water temperatures by constant light. The studied pond, Vasikkalampi, is located in the town Jvyaskyla in central Finland. The pond is slightly eutrophic and its water is used for cooling purposes by a 35 MW thermal powerplant. The cooling water is taken in the middle of the pond and it returns as heated effluent to the northern part, near the surface, about 100 m from the intake pipe. This circulation and warming of the water keeps the pond open throughout the year except during the coldest weeks in the winter when some parts freeze over. The increase of the water temperature was not sufficient to be optimal for photosynthesis in the ...

Energy Technology Data Exchange (ETDEWEB)

In the well-known devices for increasing the decontamination factor in the treatment of radioactive waste water by evaporation, which consist of narrowing devices with evaporator sump and condenser, droplets of liquid and solid particles are carried over from the breeder space, which are radioactive and therefore make the decontamination factor worse. Better results are obtained if one places a fibre bed filter between the evaporator sump and the condenser, preferably in a horizontal connecting pipe between the evaporator sump and the condenser.

Energy Technology Data Exchange (ETDEWEB)

Discusses scaling of closed systems for cooling coal gas from black coal coking. Scaling rate and factors that influence scaling are analyzed. Physical and chemical properties of scale buildup on the inner walls of pipe cooling systems are evaluated. Water pH value and its effects on scaling and solubility of chemical compounds that form scale are discussed. Use of ammonium sulfate for scale control is analyzed. Consumption rate of ammonium sulfate depends on ambient temperature, water pH value and chloride content in return water. Formulae for calculating optimum content of ammonium sulfates for scale control are derived. 3 refs.

Energy Technology Data Exchange (ETDEWEB)

Slow, unexpected displacements have been experienced in most pressurized water reactor (PWR) surge lines. Sometimes, these displacement lead to gap closure at the pipe whip restraints. These movements occur because of thermal stratification. This movement has the potential to increase stresses to valves, which may exceed the material yield stress. To understand this phenomenon, Framatome, Commissariat a l'Energie Atomique, and Electricite de France have undertaken large programs for the study of (1) thermal-hydraulic tests with a half-scale Plexiglas surge line, (2) thermal-hydraulic computations of permanent states and transients with a two-dimensional model, and (3) mechanical analysis of displacements and computation of fatigue damage due to stratification. This paper deals with the last subject. Avoiding stratification in piping by process modifications is difficult because of the high flow rate needed. ...

Energy Technology Data Exchange (ETDEWEB)

An explanation is given of what a loop heat pipe (LHP) is, and how it works. It is then shown that neutron imaging (both real time neutron radioscopy and single exposure neutron radiography) is an effective experimental tool for the study of LHPs. Specifically, neutron imaging has helped to identify and correct a cooling water distribution problem in the condenser, and has enabled visualization of two-phase flow (liquid and vapor) in various components of the LHP. In addition, partial wick dry-out, a phenomenon of great importance in the effective operation of LHPs, is potentially identifiable with neutron imaging. It is anticipated that neutron radioscopy and radiography will greatly contribute to our understanding of LHP operation, and will lead to improvement of LHP modeling and design.

Energy Technology Data Exchange (ETDEWEB)

The present authors have previously developed a new method for Probabilistic Fracture Mechanics (PFM), which they call Recursive Distribution (RD) method. The method is based on the construction of the Lebesgue-Stieltjes measure through a deterministic mapping defining a crack growth process. In the present paper, its theoretical background is first discussed, and the Lebesgue decomposition of the measure is given. Then a numerical example of a Light Water Reactor (LWR)`s piping problem is solved by the present method, and the results are compared with those of the Monte Carlo (MC) method. In addition to leakage probability, a variation in stress cycles of the marginal distribution of an aspect ratio of a semi-elliptical surface crack is calculated, which will be used in a study on LBB evaluation.

Energy Technology Data Exchange (ETDEWEB)

This patent describes a nuclear system comprising a containment airspace in which a nuclear reactor pressure vessel is disposed there being a reactor core within the pressure vessel. It comprises a heat exchanger elevated a distance above the pressure vessel; a pool of water surrounding the heat exchanger; means for venting the pool of water to an environment outside the containment; a heat exchanger entry conduit within the containment, the entry conduit having an open lower end communicating with the containment space, and an upper end connected to the heat exchanger, water-containing heated fluid present in the containment airspace incident a pressure vessel loss of coolant event entering and flowing through the entry conduit into the heat exchanger for cooling the fluid to convert water vapor therein to a condensate and separate non-condensable gasses therefrom; a gravity driven cooling ...

Energy Technology Data Exchange (ETDEWEB)

Electrical heating of subsea flowlines is an effective way to prevent wax and hydrate information, especially for long transportation distances and in low-temperature deep water. Systems are available for use in conjunction with bundles, pipe-in-pipe, and wet-thermal-insulation systems. These systems provide environmentally friendly fluid-temperature control without chemicals or flaring for pipeline depressurizing. Enhanced production is achieved because no time is lost by unnecessary depressurizing, pigging, heating-medium circulation, or removal of hydrate and wax blockages. The seabed temperature at 100-m and greater water depths may range from 7 to {minus}1.5 C, causing a rapid cooling of the hot well streams being transported in subsea flowlines. Under these supercooling conditions, vulnerable crude oils and multiphase compositions will deposit wax and asphalts; also the gas/water phase may freeze ...

International Nuclear Information System (INIS)

During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel ...

Energy Technology Data Exchange (ETDEWEB)

The Dalia field is located 210 km north west of Luanda (Angola), about 140 km from shore in 1400 meter water-depth. It was the second major discovery out of 15 made in the block 17 operated by Total. The Dalia Umbilical, Flow lines and Risers EPCI Contract was awarded in 2003. The sea-line network to connect and control the 71 wells and 9 manifolds consist of the following: 40 km of insulated pipe in pipe (12 inches into 17 inches) production flow lines; 45 km of 12 inches water and gas injection lines; 6 off 1.7 km flexible water and gas injection risers; 8 off 1.65 km flexible Integrated Production Bundle (IPB) risers; 75 km of control umbilicals. The flow assurance and associated insulation requirement of the production transport system was one of the main challenges of the project. With a crude temperature of 45 deg C at the wellhead and the required minimum temperature of 35 ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes examples of the damage resulting from the impact of a whipping pipe on a nearby pressurised pipe. The work is a by-product of a study of the motion of a whipping pipe. The tests were conducted with small-diameter pipes mounted in rigid supports and hence the results are not directly applicable to large-scale plant applications where flexible support mountings are employed. The results illustrate the influence of whipping pipe energy, impact position and support type on the damage sustained by the target pipe.

Energy Technology Data Exchange (ETDEWEB)

Contamination and blockages of the cooling tubes in the turbine condenser disturb the heat transfer, thereby causing power losses at the turbine and increasing the fuel demand. Corrosions cause tubing leakages which require operating downtimes and reduce the lifetime of the pipes. Tube cleaning systems and backflushing cooling water filters eliminate these problems. Nevertheless it can come to coatings in the condenser tubes, if the tube cleaning equipment does not operate optimally or if coarse dirt is entered. Under this aspect, the author of the contribution under consideration reports on these problems on the basis of practical examples. The author gives references to the optimized operation of the tube cleaning system and the cooling water filtration.

Science.gov (United States)

... rate on the tensile properties of SA-106 carbon steel pipe, in support of analysis and experimental modeling of postulated pipe whip in nuclear ...

Energy Technology Data Exchange (ETDEWEB)

The verification test program on zinc injection applicability to Japanese BWRs was started in 1997. Laboratory tests using high temperature water loops under BWR reactor water conditions are in progress. This paper is an interim report on results obtained so far. Co-58 and Zn-65 were simultaneously used in the Co radioactivity buildup test to evaluate zinc injection suppression effects towards cobalt deposition on pre-oxidized stainless steel. The following results were obtained. The Co deposition was suppressed effectively by Zn injection, even when there was a pre-oxide film. For the test piping that had the pre-oxide film formed under the NWC (normal water chemistry) condition, when soaked under the HWC (hydrogen water chemistry) condition a large amount of Co-58 was taken into a small part of the inner layer. The distribution ratio of Co-58 in the inner layer and outer layer of ...

Energy Technology Data Exchange (ETDEWEB)

When a rotary excavator is operated at locations where there is artesian water, the aquiclude is fractured under pressure of the artesian water upon the penetration of the pile tip through the aquiclude. Since the equipment is provided with a gap for the reduction of friction between the casing and the excavation face, soil and sand near the pile tip burst forth out of the ground together with underground water through the casing or along the outer circumference of the casing. The newly contrived method introduced here is a double pipe process, in which a large casing (2.0m in diameter) is driven until it lands on the aquiclude, water is injected into the casing for the creation of equilibrium between the artesian head and the head in the casing, and finally a casing as large as the pile (1m in diameter) to be installed is used for the excavation of the artesian ...

Energy Technology Data Exchange (ETDEWEB)

Despite successful reduction of the general lead exposure, this heavy metal is still a matter of public concern due to the fact that associations with intellectual impairment or delayed puberty are found to correlate with very low lead blood concentrations. Lead in tap water is still an important contribution to lead exposure which may cause health risk for infants. Therefore, lead pipes should be completely sanitated by exchange against pipes made from more healthy materials. (orig.) [German] Trotz erfolgreicher Reduktion der allgemeinen Belastung ist Blei auch heute noch umweltmedizinisch relevant, weil es moeglicherweise bei niedrigeren als bisher angenommenen Belastungen gesundheitlich nachteilige Wirkungen, insbesondere waehrend der fruehkindlichen Entwicklung des Nervensystems, ausloest. Insbesondere Blei aus bleiernen Trinkwasserleitungen ist eine Belastung, die fuer Saeuglinge und Kleinkinder nach wie vor ein ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

J-STORE (Japan)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The technology developed here will exploit the ability of microorganisms to remove dissolved metals from aqueous solutions. Microbial sorbents for uranium will be immobilized biosorbents will be deployed ex situ within flow-through reactors for the continuous or semicontinuous treatment of recovered wastewaters. The proposed technology will primarily be applied within a pump-and-treat process using immobilized biosorbents for the large-scale, long-term remediation of uranium-laden surface water or groundwater impoundments (environmental restoration). The technology may be equally useful as an ``end-of-pipe`` treatment of process effluents (waste management). Successful operation of this process will achieve immobilization of the targeted waste and accompanying volume reduction.

Energy Technology Data Exchange (ETDEWEB)

Westinghouse Electric Germany GmbH has developed fluid dynamic models for medium-actuated armatures using the thermal hydraulic code RELAP5 in order to reach a more realistic description of the armature behavior including fluid-structure interactions in case of transient flow conditions in piping systems. The contribution is concerned with the modeling of damped check valves. The model allows the description of the behavior during opening and closure of a check armature. The calculated results show good agreement with the available measured data.

International Nuclear Information System (INIS)

... failures fftf reactor heat transfer hydraulics loss of coolant pipes primary coolant

Energy Technology Data Exchange (ETDEWEB)

This study presents the results of an 18-year long investigation of pipe deterioration in cyclone slag slurry transport. The goal was to study pipe behaviour in this extremely abrasive service and select an optimum piping material. Comparisons are given for high quality alloy cast steel pipes and pipes alined with cast basalt rings marketed under the name Abresist.

International Nuclear Information System (INIS)

Object: To prevent a sudden drop in the level of a coolant in a annular pipe encased within a downcomer pipe. Structure: The coolant levels in annular pipes encased within downcomer pipes are simultaneously measured by level gauges which generate signals representative of coolant levels. The signals are fed to a level control system which will actuate valves to regulate the cover gas pressure in order to average the level differences among the annular pipes in different downcomer pipes. (Kamimura, M.).

International Nuclear Information System (INIS)

PWR plants have made efforts to maintain the long-term integrity of the steam generators (SG) by reducing the amount of corrosion products entering the secondary side of the SG. Iron entered the SG can cause several problems: degraded heat conductivity of the SG tubes in locations where iron is deposited, water level oscillations in the SG due to tube support plate hole blockage, and initiation and propagation of inter-granular attacks (IGA) and stress corrosion cracking (SCC). One of the most effective measures, high all-volatile treatment (AVT) chemistry has been applied to actual plants to reduce the flow-accelerated corrosion (FAC) coming from the carbon steel piping. The secondary water chemistry at Genkai NPS 1 and 2 changed, from the Low AVT chemistry to the High AVT chemistry, in November 2006. In this paper, we will describe the results of experiments in applying the use of High pH water in the ...

CERN Document Server

The Cooling and Ventilation Group has started the LHC construction work in September 1999 and will get into full activity when LEP will be stopped and dismantled: in total 12 major contracts for an amount of about 120 MCHF will be established to build the needed installations for the LHC. The author will report on the current works that are in progress on the different LEP Points distinguishing between the Ventilation and the Water Cooling installations. The Ventilation work, completed in the new surface buildings in Points 18, is currently held in Points 4 and 5. Point 1 will follow in the near future. The work for the Cooling plants comprehend the pumping stations, the cooling towers and the chilled water production stations in Points 1 and 5, the buried pipes in Points 1 and 4. For all of these activities, an updated report of the progress of the work, of the planning and of the expenses is given. Finally, a short ...

Energy Technology Data Exchange (ETDEWEB)

A technique for the measurement of the total hemispherical emittance of pipe surfaces is described, and design and operational details are given. The technique is conceptually simple. A long test pipe (e.g., 3.4 m) is mounted concentrically inside a Pyrex glass pipe. The system is evacuated, and the test pipe is heated by means of an electrical resistance heater. Heat transfer from the test pipe to the enclosure is almost solely radiative, allowing an average emittance for the test pipe and the Pyrex pipe and the electrical power input to the heater. By varying the electrical power level, one can measure the test pipe emittance as a function of temperature. By using a simple correction to account for the finite length of the test pipe, one can calculate the results using the simple expression for ...

Energy Technology Data Exchange (ETDEWEB)

The unsteady two-dimensional laminar flow of a viscous incompressible electrically conducting micro polar fluid via a porous medium past a semi-infinite vertical porous moving plate in the presence of a transverse magnetic field is studied. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micro polar fluid with a suction velocity varying with time. The effects of material parameters on the velocity and temperature fields across the boundary layer are investigated. The method of solution can be applied for small perturbation approximation. Numerical results of velocity and temperature distributions of micro polar fluids are compared with the corresponding flow problems for a Newtonian fluid. (author)

Scientific Electronic Library Online (English)

Abstract in english Numerical solutions for the effects of radiation on a MHD convective heat transfer past a semi-infinite porous plate with a magnetic field are obtained. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The magnetic field acts perpendicular to the porous surface which absorbs the fluid with a suction velocity varying with time. The gov (more) erning equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation technique and then are solved numerically by using the shooting method. The effects of the various parameters on the velocity, temperature profiles as well as the surface skin-friction and surface heat transfer are illustrated graphically.

International Nuclear Information System (INIS)

The device of the present invention improves reactor safety by suppressing lowering of water level in a shroud which surrounds a reactor core, even upon occurrence of rupture of pipelines in an emergency reactor core cooling system in a recycling pump-incorporated type reactor. Namely, an opening of each of cooling systems which forms the emergency reactor core cooling device in a reactor pressure vessel is disposed above the upper end of the reactor core. Further, it also comprises an independent high pressure water injection system, gravitational dropping type water injection system and an automatic depressurization system. With such a constitution, even if rupture of pipelines in the system should be assumed, coolants never flow directly from the shroud which surrounds the reactor core. In addition, there are no pipelines to be ruptured below the upper end of the reactor core with respect to the structure. Accordingly, a ...

International Nuclear Information System (INIS)

Power plant components exposed to environments such as water and soil are susceptible to severe corrosion. Many times the effect of corrosion in power plant components can be catastrophic. The problem is aggravated for underground pipelines due to additional factors such as large network of pipelines, proximity to earth mat, high voltage transmission lines, corrosive chemicals, inadequate approach etc. Other components such as condenser water boxes, internals of pipelines, clarifier bridge structures, cooling water inlet gates and pipes etc. which are in continuous contact with water, are subjected to severe corrosion. The nature and locations of all such components are at places which are not accessible for routine maintenance and hence they require long term reliable protection against corrosion. Experience has shown that anti-corrosive coatings are inadequate in preventing ...

Energy Technology Data Exchange (ETDEWEB)

A field study was conducted in Ontario to evaluate the suitability of grouted piles for transmission tower foundations. The grouted piles were assessed in terms of the installation procedure and its foundation performance subjected to uplift loads. Two types of grouted piles, the H-pile and the pipe-pile, were evaluated and compared with conventional ungrouted H-pile foundations. Difficult soil conditions were encountered consisting of a deep deposit of loose to compact sand with a high water table. Both the grouted pipe-pile and the grouted H-pile developed uplift capacities more than double that of the conventional H-pile with the same embedment length at the test site. The grouted H-pile is recommended as a viable transmission line foundation in weak soils due to the significant improvement in its foundation performance, with minor modifications to the construction procedure. 3 refs., 17 figs., 12 tabs.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature. The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray gas, the augmentation observed are negligible. For the range of values studied ...

Science.gov (United States)

In early 2006 we designed and built low energy consumption, pump-operated system, for dosing of the liquid nutrient in the summer 2006 season. This operated successfully, and the system was used again during the 2007 and 2008 seasons for dosing. During the early winter period, 2008, laboratory tests were made of the liquid nutrient pump system, and it was noted that small amounts of air were being entrained on the suction side of the pump, during conditions when the inlet pressure was low. It was believed that this was the cause of diurnal fluctuations in the flow supplied, characteristic of the 2007 year flow data. Replacement of '0' rings on the inlet side of the pumps was the solution to this problem, and when tested in the field during the summer season, the flow supplied was found to be stable. A decision was made by the IKERT committee at the meeting of 20th to 21st May 2008 (held in Coeur d'Alene, Idaho) to use an injection flow ...

Energy Technology Data Exchange (ETDEWEB)

EPRI has sponsored an experimental program in the pipe whip impact and pipe rupture and depressurization areas. Sixteen pipe whip tests were performed with 3 in Schedule 80 (or 10) carbon steel pipes impacting on rigid target or concrete slab. The major testing parameters include distance, impact location, pipe rupture location, and concrete slab thickness and strength. The piping crushing at impact correlates with impact force and target response behavior. Conservatism was established by comparing measured and calculated impact forces. The pipe rupture and depressurization tests were carried out using 6 in stainless steel and carbon steel pipes under either PWR or BWR fluid conditions. These tests are of axial crack with initial machined-in surface flaw. It was found that pipe rupture would occur ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents experimental and analytical results of pipe whip tests performed under PWR LOCA conditions using a test pipe of 4-inch diameter and U-shaped restraints. In the tests, the effects of the overhang length on the pipe whip behavior of the piperestraints system were studied by measuring the strains and deformations of the test pipe and restraints, and the restraints forces. The equation for predicting the maximum strain at the outer surface of the pipe was derived using a static equilibrium condition. The calculated maximum strains at the outer surface of the pipe agree fairly well with experimental data. The dynamic response analysis of the pipe-restraints system was conducted by the finite element program ADINA. The applicability of the ADINA program to the pipe whip analysis is made clear through this ...

Energy Technology Data Exchange (ETDEWEB)

Design of pipe whip restraints requires a knowledge of the maximum allowable unsupported pipe length. This paper presents a numerical method for calculating this critical length of the pipe. Salient features of the method are: (1) as a flow rounds an elbow, it exerts a transverse kick and an axial thrust to the pipe, both the axial thrust and the bending moment are considered; (2) the jet force is applied in an abrupt manner, the dynamic amplification factor (DAF) is determined from the load-deflection (H-{Delta}) curve of the pipe, by taking into consideration large strain, large deformation and the nonlinear stress-strain relationship of the piping material; (3) the ultimate capacity of the pipe under the combined action of an axial force and a bending moment is governed by an interaction formula. The maximum unsupported ...

International Nuclear Information System (INIS)

On the basis of environmental considerations, a high temperature gas cooled reactor (HTGR) was proposed as the heat source for the Natuna project for CO_2 conversion. To convert CO_2 to useful products, a large amount of high quality water is required for the chemical processes, boilers and other purposes. One LNG production train (maximum of six trains) would produce 0.4 x 10"9 SCF/d of saleable gas and 1.4 x 10"9 SCF/d of CO_2 (in the case of the Exxon process). This CO_2 gas would then be converted to automobile fuel (methane, methanol), which requires a large amount of water. Natural gas from an off- shore gas field is piped to the petrochemical complex on Natuna Island (about 228 km). Natuna is a small island that, apart from sea water, does not have much available water. The desalination process is considered to be the only solution to the water demand ...

International Nuclear Information System (INIS)

Previous flow regime studies have been for horizontal, vertical, and inclined pipe flow. As such, only a few studies have been performed on bundle geometries. The present paper examines the flow regimes for a vertical hexagonal flow channel with and without a finned fuel bundle. This type of a 36 finned rod hexagonal fuel bundle in parallel hexagonal flow channels is used in a MAPLE (Multi- purpose Applied Physics Lattice Experimental) type nuclear reactor. An experiment apparatus was designed consisting of the flow channel, inlet plenum and an air-water separator. The inlet plenum is used to provide a uniform mixture of air and water before entering the hexagonal flow channel. A turbine flow meter is used to determine the water flow rate. The turbine flow meter is calibrated for a low flow range and limits the measurable flow to 50 l/min. Flow pattern observation is determined by a SONY video camera, ...

Science.gov (United States)

The goal of this research project was to determine the eff ects of geometric and mechanical parameters characterizing the soil-structure interaction developed in a buried pipe installation. Parameters such as pipe ring stiff ness, bedding thickness, trenc...

Energy Technology Data Exchange (ETDEWEB)

Burner for feeding a solid and a liquid or gaseous fuel to a kiln comprises a central supply pipe for liquid or gas surrounded concentrically by a first pipe providing an annular passage through which primary air is supplied. Concentrically surrounding that pipe is a second pipe providing an annular channel for supply of solid fuel in carrier air stream. The outlet end of the first concentric pipe is closed by a plate fixed mounted at the pipe end and providing multiple nozzles having their axes parallel to the burner axis. The surface of the plate facing the burning zone provides a divergence opening for the central pipe while the inner surface is formed with helical teeth. These are engaged by complementary teeth mounted on the end of the central pipe which is rotatable and biased by springs so that the teeth are in ...

Science.gov (United States)

A theory for the mass transfer process was developed. It was assumed that the largest convective motions in the flow control the rate of mass transfer. Measurements of mass transfer coefficients for the absorption of oxygen by water films were made for concurrent flows in a horizontal rectangular channel, and for concurrent and free-falling downflow in a one-inch pipe. The measured values of the Sherwood number for concurrent flows were up to three times as great as would be predicted from this relation. This increase in Sherwood number was correlated with a dimensionless group similar to a Martinelli parameter which is characteristic of two phase flows. An explanation for this effect is given in terms of the way that the scales of the convective motions are related to bulk flow parameters.

Energy Technology Data Exchange (ETDEWEB)

With the issuance of the Decommissioning Rule (July 27, 1988), nuclear power plant licensees are required to submit to the US Regulatory Commission (NRC) for review, decommissioning plans and cost estimates. This user`s manual and the accompanying Cost Estimating Computer Program (CECP) software provide a cost-calculating methodology to the NRC staff that will assist them in assessing the adequacy of the licensee submittals. The CECP, designed to be used on a personnel computer, provides estimates for the cost of decommissioning PWR plant stations to the point of license termination. Such cost estimates include component, piping, and equipment removal costs; packaging costs; decontamination costs; transportation costs; burial costs; and manpower costs. In addition to costs, the CECP also calculates burial volumes, person-hours, crew-hours, and exposure person-hours associated with decommissioning.

British Library Electronic Table of Contents (United Kingdom)

The heat transfer a characteristics and friction factor in the horizontal double pipes of flat tubes with full length helical screw element of different twist ratio and helical screw inserts with different spacer length are investigated. Cold and hot water are used as working fluid in tube side and shell side respectively. The experiments covered a range of Reynolds numbers 5.7x102Re1.31x103. The effect of spacer length on the heat transfer augmentation and friction factor and the effect of twist ratio on heat transfer augmentation and friction factor have been presented separately. The study shows that, the Nusslet number (Nu) and friction factor (f) decrease with the increase of S or Y for flat tube. The comparison between the data of present plain circular with that of previous plain ci...

International Nuclear Information System (INIS)

A two-phase flow regime map is developed experimentally and theoretically for a vertical hexagonal flow channel with and without a 36-finned rod hexagonal bundle. This type of flow channel is of interest to MAPLE-type nuclear research reactors. The flow regime maps are determined by visual observations and observation of waveforms shown by a capacitance-type void fraction meter. The experimental results show that the inclusion of the finned hexagonal bundle shifts the flow regime transition boundaries toward higher water flow rates. Existing flow regime maps based on pipe flow require slight modifications when applied to the hexagonal flow channel with and without a MAPLE-type finned hexagonal bundle. The proposed theoretical model agrees well with experimental results.

Energy Technology Data Exchange (ETDEWEB)

This paper describes a nonlinear dynamic analysis of TVA high energy line pipe whip tests using the ABAQUS-EPGEN code. The analysis considers the effects of large deformation and strain rate on resisting moment and energy absorption capability. The numerical results of impact forces, impact velocities, pipe strains, and reaction forces at pipe supports are compared to the TVA test data. The calculated pipe whip impact time and forces are also compared with those predicted using current industry practice. The calculated pipe support reaction forces are found to be in good agreement with the TVA test data except for some peak values at the very beginning of the pipe break. These peaks are believed to be due to stress wave propagation which cannot be addressed by the ABAQUS code. Both elbow crushing and strain rate have been approximately simulated. The effects are ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of pipe rupture studies in JAERI is to perform model tests on pipe whip, restraint behavior, jet impingement and jet thrust force, and to establish a computational method for analyzing these phenomena. This report presents the analytical results of 4-inch pipe whip tests under BWR LOCA conditions. Dynamic response analyses were performed using the general-purpose finite element program ADINA. The test pipe was modelled by straight beam elements and the four restraints were modelled by a single truss element. The analytical results were compared with the experimental results. Impact time and maximum total restraint force showed good agreement with experimental results. On the other hand, pipe strain and pipe deflection could not be predicted so well. The reason for this is that the sliding of the restraint during the pipe whip ...

International Nuclear Information System (INIS)

To facilitate potential cost savings in pipe whip protection design, TVA conducted a 1'' high pressure line break test to investigate the pipe whip behavior. The test results are available to EPRI as a data base for a generic study on nonlinear dynamic behavior of piping systems and pipe whip phenomena. This paper describes a nonlinear dynamic analysis of the TVA high energy line tests using ABAQUS-EPGEN code. The analysis considers the effects of large deformation and high strain rate on resisting moment and energy absorption capability of the analyzed piping system. The numerical results of impact forces, impact velocities, and reaction forces at pipe supports are compared to the TVA test data. The pipe whip impact time and forces have also been calculated per the current NRC guidelines and compared. The calculated ...

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 ...

International Nuclear Information System (INIS)

The possibility of electrochemical corrosion of carbon steel at the rate of 3.25 x 10"-"5 A/cm"2 in water was examined under the conditions present during an accidental pipe rupture at the Mihama nuclear power plant: liquid conductivity, 7.5 #mu#S/cm; dissolved oxygen concentration, 5 ppb or less; pH 8.6#propor to#9.3; ferrous ion concentration, 20 ppb or less; temperature, 142 C. The corrosion rate of iron in a micro-cell with a dissolved oxygen reduction cathode was estimated to be only 1/400 of the preceding rate. On the other hand, that in a micro-cell with a hydrogen ion reduction cathode was estimated to be as high as 1/10 of the preceding rate, that is, 3.25 x 10"-"6 A/cm"2. Two important factors may have influenced the corrosion rate: the remarkable wall thinning, which must have been the direct cause of the rupture of the pipe, was located close to, and downstream from, an orifice; and, the ...

International Nuclear Information System (INIS)

In order to study the two-phase natural circulation and flow termination during a small break loss of coolant accident in LWR, simulation experiments have been performed. Based on the two-phase flow scaling criteria developed under this program, an adiabatic hot leg U-bend simulation loop using nitrogen gas and water and a Freon 113 boiling and condensation loop were built. The nitrogen-water system has been used to isolate key hydrodynamic phenomena from heat transfer problems, whereas the Freon loop has been used to study the effect of phase changes and fluid properties. Various tests were carried out to establish the basic mechanism of the flow termination and reestablishment as well as to obtain essential information on scale effects of parameters such as the loop frictional resistance, thermal center, U-bend curvature and inlet geometry. In addition to the above experimental study, a preliminary modeling study has been carried out for ...

Energy Technology Data Exchange (ETDEWEB)

The prediction of two-phase flow regime in the horizontal pipings during a loss-of-coolant accident (LOCA) is important for safety analysis of a pressurized water reactor (PWR). The flow regime transition conditions for a horizontal two-phase air-water flow were studied using a large-height, horizontal rectangular duct test section. The duct dimensions were 700 mm in height, 100 mm in width and 28.3 m in length. The experimental criterion for the flow regime transition from the stratified to slug flow regimes, in terms of the local void fraction and the non-dimensional gas-liquid relative velocity, agreed qualitatively with the prediction by the Mishima-Ishii model that is based on an idea that the interfacial waves with the largest growth rate will develop into a slug. However, the transition in the experiment occurred at systematically lower (by about 40 %) relative velocities than the prediction by the Mishima-Ishii ...

International Nuclear Information System (INIS)

A detailed outline of the application of the MELCOR and RELAP5/MOD3.1 codes to the analysis of the thermohydraulic response and determination of other parameters of the medium on the floor is given for several classes of secondary coolant circuit accidents along with the description of the related facilities. An overview is presented of the maximum values and time behavior of the thermohydraulic parameters, pressure, temperature, relative humidity, and water level on the floor. Transverse rupture of the steam generator, main steam header, or main feedwater header piping during normal operation is considered as the initiating event. Pressure is only 10% higher than the atmospheric pressure. Air temperature attains a value as high as 100 degC. Relative humidity is 100%, persisting as long as the steam source is available. The water level is typically about 8 cm and never exceeds 15 cm. (M.D.). 16 tabs., 37 figs., 32 refs.

International Nuclear Information System (INIS)

... p. SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS algorithms

Energy Technology Data Exchange (ETDEWEB)

The performance of a commercial heat pipe was investigated both experimentally and theoretically. The effect of the temperature difference, the surface area ratio, and the operational conditions on the performance were studied. The heat flow rate and the vapor temperature were estimated on a ready-made commercial heat pipe. Its performance varied considerably with operational conditions. Theoretical consideration of a mathematical model and several nomographs are also presented. This work is applicable to the design and use of heat pipes in the field.

International Nuclear Information System (INIS)

Series of pipe rupture tests have been performed at the Japan Atomic Energy Research Institute to demonstrate the safety of the primary coolant circuits in the event of pipe rupture in nuclear power plants. The pipe whip tests have been conducted to study the dynamic response of the pipe and restraints. The results of the pipe whip tests using test pipes of 4-inch in diameter under the BWR LOCA conditions (285"0C, 6.8 MPa) were reported in the previous paper F8/5 of the 6th SMiRT. The present paper describes the results of the pipe whip tests using test pipes of 6-inch in diameter. The test pipe was made of Type 304 stainless steel and was 165.2 mm in outer diameter and 11.0 mm in thickness, and was fixed at the pipe support so that the length of the test section was 3000 mm. The ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

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)

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. Therefore, two cases are investigated: GDH impact on an adjacent GDH and its attached piping; and GDH impact on an adjacent reinforced concrete wall. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large ...

Energy Technology Data Exchange (ETDEWEB)

Design methods and parameters are described which are addressed when considering consequences of a postulated pipe rupture event in a nuclear plant design. Parameters discussed are break opening time and size, resultant blowdown characteristics of the effluent from the broken pipe, jet reaction and impingement loading, pipe motion, and pipe impact loading on steel and concrete structures. The impact the various parameters have on overall plant designs and conservatisms inherent in each consideration are evaluated in a qualitative nature. Finally, recommendations are provided for each parameter discussed for further evaluation and study.

International Nuclear Information System (INIS)

The paper describes the experimental and analytical results of the pipe whip tests performed under the PWR LOCA conditions using 4, 6 and 8 inch test pipes. The tests were carried out at an initial pressure and a temperature of 15.7 MPa and 325 "0C. Two different types of tests were performed. One was the cantilever type pipe whip test using the test pipe of 3000 mm in length and U-shaped restraints. The other was the cross-over leg pipe whip test using a 1/6 model of piping in the PWR nuclear power plants. The cantilever type pipe whip tests were performed to investigate the influences of overhang length and pipe diameter on the pipe whip behavior. The movement of the test pipe is limited effectively by the restraints when the overhang length is short. The restraint force ...

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the research conducted during Budget Period One on the project ''Improved Natural Gas Storage Well Remediation''. The project team consisted of Furness-Newburge, Inc., the technology developer; TechSavants, Inc., the technology validator; and Nicor Technologies, Inc., the technology user. The overall objectives for the project were: (1) To develop, fabricate and test prototype laboratory devices using sonication and underwater plasma to remove scale from natural gas storage well piping and perforations; (2) To modify the laboratory devices into units capable of being used downhole; (3) To test the capability of the downhole units to remove scale in an observation well at a natural gas storage field; (4) To modify (if necessary) and field harden the units and then test the units in two pressurized injection/withdrawal gas storage wells; and (5) To prepare the project's final report. This report ...

Energy Technology Data Exchange (ETDEWEB)

Polyethylene gas piping is expected to be in service for times on the order of 50 years depending on service conditions. Therefore research research on piping materials and pipes has two principal objectives: (a) developing methods for predicting when a pipe will fail and (b) improving the material for piping. The prediction of long time failure hinges on the development of short time test methods which relate to long time failure. The improvement in the behavior of current materials also hinges on the use of test methods of short duration relative to the anticipated life time of the pipe in service. One of the primary criterion for an acceptable test method is that it produces the same type of failure as is observed after long time failure in service. It has been found that P.E. pipe material fails in a brittle mode after long periods of ...

Energy Technology Data Exchange (ETDEWEB)

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. The cases of GDH impact on an adjacent GDH and its attached piping are investigated in this paper. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material characteristics. ...

Energy Technology Data Exchange (ETDEWEB)

An independent investigation of pipe welding leaks from the Low-Level Waste 2 (LLW2) Skid-B System for the possibilities of improper welding (IW), microbiologically influenced corrosion (MIC), sensitization, chloride pitting corrosion (CPC), and intergranular stress corrosion cracking (IGSCC) was conducted. The results show the prevailing mechanisms that caused the leaks are identified as IW, CPC, and the improper selection of weld filler material for the base metals in an environment of the North Plateau underground water. These is no evidence of MIC, sensitization, or IGSCC. The chloride pitting corrosion mechanism that took place at all the welds are also described. All the pipelines were replaced with polyvinyl chloride (PVC) for cost saving and the LLW2 Skid B System has been successfully operating since 1999. This report summarizes the findings and recommendations associated with preventive measures for future operations. The LLW2 ...

Energy Technology Data Exchange (ETDEWEB)

An apparatus is described for measuring the total hemispherical emittance of pipes of a length suitable for use in a prototype solar collector. The calorimetric method used requires measurements of the temperatures of the surface of the test pipe and of a concentric outer cylinder and measurement of the electrical power used to heat the test pipe. Measurements were made of the total hemispherical emittance of black chrome, nickel, and bare steel pipes as a function of temperature. The emittance of the black chrome surfaces increased significantly from an extrapolated value of about 0.1 at 25 deg C to values on the order of 0.3-0.4 at 300 deg C. The extrapolated values for black chrome agreed with measurements made using other techniques at room temperature. The results for the nickel-plated pipe agreed with total emittance calculated from spectral reflectance data.

Energy Technology Data Exchange (ETDEWEB)

The analytical results of blowdown characteristics and thrust forces were compared with the experiments, which were performed as pipe whip and jet discharge tests under the PWR LOCA conditions. The blowdown thrust forces were obtained by Navier-Stokes momentum equation for a single-phase, homogeneous and separated two-phase flow, assuming critical pressure at the exit if a critical flow condition was satisfied. The following results are obtained: (1) The node-junction method is useful for both the analyses of the blowdown thrust force and of the water hammer phenomena. (2) The Henry-Fauske model for subcooled critical flow is effective for the analysis of the maximum thrust force under the PWR LOCA conditions. The jet thrust parameter of the analysis and experiment is equal to 1.08. (3) The thrust parameter of saturated blowdown has the same one with the value under pressurized condition when the stagnant pressure is chosen as the saturated ...

Energy Technology Data Exchange (ETDEWEB)

Steam generators (SG) are the weak link of nuclear power plants, their service life is shorter than the service life of other NPP components. This paper is dedicated to a statistical analysis of SG damages and failures. Heat exchanging tubes (HET) are the most damaged elements in SG, there are on average 286 plugged or repaired tubes in each operating SG. The usually mechanisms of tube failure are the following: denting, corrosion at tube outside, pitting, fretting, and circular crack propagation. Most of damages are located in the transition zone above a tube plate. This study shows that the factors that are involved in the SG HET fault probability are: - design features of SG and secondary equipment elements (high pressure feed heaters (HPFH), low pressure feed heater (LPFH)), - water chemistry at different points of condensate feed pipe, composition and density of deposits on HET surface, efficiency of mechanical and chemical washing, - the ...

Energy Technology Data Exchange (ETDEWEB)

Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas pipelines in equilibrium ...

Energy Technology Data Exchange (ETDEWEB)

The oil production is largely transported in pipelines operating in two-phase flow regime. The predominant flow pattern is the slug flow, which is characterized by intermittent succession of liquid slugs followed by long gas bubbles. This paper addresses specifically to the capture of the intermittently feature of slug flows using a compressible slug tracking model. The intermittency rules the bubble to bubble interactions, defines the bubble coalescence rate, changes the size of the bubbles, alters the pressure drop among other flow properties. The inlet sizes and velocities of the bubbles and slugs are estimated based on experimentally determined distributions characterized by its mean value and standard deviation. The inlet intermittency, transmitted through the inlet boundary condition, results in a better match of the fluctuating flow properties along the pipe. The simulations are carried out with air-water flow and the results present ...

International Nuclear Information System (INIS)

Presently no one knows whether electromagnetic fields (EMFs) play a role in human cancer or other ailments, though epidemiological studies over the years have suggested that possibility. A study by the Electric Power Research Institute attempted to quantify everything it could about the magnetic environment of a home, identifying not only major sources of magnetic fields, but also their frequencies, strengths, and how they fall off with distance. Sources of a homes magnetic environment include appliances, overhead powerlines, and grounding connections to metallic water pipes. Fields will vary over time, depending on how much current is passing through the electrically conductive sources. Additional contributors to a home's magnetic background may include unusual wiring in the walls, underground power lines, and near-by high voltage transmission lines. This paper summarizes the study results, indicating weak, persistant EMFs may dominate, but ...

International Nuclear Information System (INIS)

The design boron concentration of the Boron Injection Tank (BIT) in Daya Bay Nuclear Power Station is 21000 #mu#g/g. The BIT should operate under high temperature to avoid boron crystallization, causing higher evaporation, frequent water makeup, higher deposition and pipe blockage to decrease the operability of the safety injection system. The author proposes to decrease the boron concentration in BIT from 21000 #mu#g/g to 7000 #mu#g/g to solve the existing problem. The safety analyses (core DNBR and containment response) are conducted and other impacts are evaluated for the BIT reduction. The analysis results show that the core DNBR meets the safety criterion and the containment pressure is within the design value for the steam line rupture accident after the BIT reduction. The feasibility study report of Daya bay BIT reduction has been approved by NNSA. The site implementation of BIT reduction has been finished successfully

Energy Technology Data Exchange (ETDEWEB)

Thermal-hydraulics analysis can be used to determine location and magnitude of leaks inside a pressurized water reactor (PWR) containment, as required by plant technical specifications. The major advantage of this detection method is that it minimizes radiation exposure of maintenance personnel because most of the leak detection process is performed from the control room outside the containment. In addition, such a program allows for the elimination of pipe whip restraints and jet impingement shields, eliminating costs for maintenance of these supports and shields in older plants and lowering construction costs for new plants. Previously, only simple single-node containment models were used for determining leakage magnitude. This paper presents a more sophisticated multinode approach for determining the magnitude and location. The resulting sensitivities to leak can be programmed into the plant's computer system. In this way, the ...

Energy Technology Data Exchange (ETDEWEB)

The two-phase annular regime is characterized by a high velocity gas stream flowing through the core of the tube surrounded by a thin, highly agitated liquid film flowing concurrently along the tube wall. Part of the liquid may be entrained as droplets in the gas phase. The specific goals of this study were to measure fully developed rates of interchange and entrained fraction over a wide range of flow variables in the upward configuration of the annular regime, to obtain a more fundamental understanding of liquid interchange phenomena via studies of liquid film characteristics and to develop an improved design correlation for the entrained fraction. Towards this end, air-water experiments were conducted in two vertical pipe lines, 2.54 and 4.20 cm in diameter. Air velocities ranging from 20 to 120 m/s and total liquid flow rates ranging from 10 to 100 g/s were investigated. Two models for the rate of atomization, proposed by Tatterson (1975) ...

Energy Technology Data Exchange (ETDEWEB)

A method to select, among several commercial diameter options, the most economic combination of pipeline networks is presented. These networks comply with the discharge conditions in the pipes and pressure in the knots. It is applied a static method for the hydraulics analysis of the Engineering Institute of the Universidad Nacional Autonoma de Mexico (UNAM) and an optimization technique to reduce the number of calculations. [Spanish] Se presenta un metodo para seleccionar, de entre varias opciones de diametros comerciales, la combinacion que forma la red de tuberias mas economica que satisface las condiciones de gasto en los tubos y de presion en los nudos de la misma. Para el analisis hidraulico se emplea un metodo estatico del Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM) y se aplica una tecnica de optimacion para reducir el numero de calculos y alcanzar la solucion.

Energy Technology Data Exchange (ETDEWEB)

Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet impingement shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. These leak rates depend on the crack-opening area of a through-wall crack in the pipe. In addition to LBB analyses, which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section 11. This study was requested by the NRC to review, evaluate, and refine current analytical models for ...

Energy Technology Data Exchange (ETDEWEB)

Pipe whip tests or jet discharge tests have been performed at the Japan Atomic Energy Research Institute, which simulate the instantaneous guillotine break of primary coolant piping in nuclear power plants. This paper describes the results of the 4-inch pipe whip tests(RUN 5407, 5501, 5504, 5603), under the BWR LOCA conditions, which were performed from 1979 to 1981. The test pressure was 6.8 MPa and test temperature 285/sup 0/C. In these tests, clearance was kept constant at the value of 100 mm and overhang lengths were 250, 400, 550 and 1,000 mm, respectively. The main purpose of these tests is to investigate the effect of overhang length on pipe whip behavior. From the tests results, the pipe movement is effectively limited by the restraints if the overhang length is 250 mm or 400 mm. The deformation of the test pipe and restraints becomes large with ...

Energy Technology Data Exchange (ETDEWEB)

From the results of the In-Service Inspection (ISI) measuring the wall thickness of outlet (hot-leg side) feeder pipes performed at two Canadian nuclear power plants, Point Lepreau and Gentilly-2 in 1995 and 1996, respectively, the wall thinning degradation of feeder pipes at the bend part was found to be much more severe than expected. It has been well known that such wall thinning of feeder pipes is caused by the flow accelerated corrosion (FAC) which is one of the mechanical-chemical degradation mechanisms affecting the integrity of piping systems. For the Wolsung unit 1, the wall thickness measurements have been performed during every overhaul period since 1996. The wall thinning rates at the bends of outlet feeder pipes were assessed to exceed the design value. However, for the Wolsung units 2, 3 and 4, the wall thinning rates of all the outlet feeder pipes ...

Energy Technology Data Exchange (ETDEWEB)

Prior to 1986, the abrasive coking coal processed in the coal preparation plant at the Fording River operation at Elkford, British Columbia, was destroying the mild steel straight pipe and elbows at such a rate that they were having to be replaced annually and every 6-8 months respectively. To solve the problem, Fording River began to replace existing pipe and elbows with fused-cast, basalt-lined abrasion-resistant pipe, elbows and fittings manufactured by Abresist Corp. of Urbana, Indiana. The Abresist straight pipe has lasted 7 seven years and the Abresist elbows 5 years and both are still in use. 2 photos.

International Nuclear Information System (INIS)

... Power Company, Tokyo (Japan) Ishida, T. Japan Atomic Power Company,

Energy Technology Data Exchange (ETDEWEB)

Outline: Discuss far-side weld problem and phased array techniques applied. Describe laboratory work on flawed piping specimens using L- and S-wave arrays and provide synopsis of results. Discuss conclusions ofr capability of phased array as applied to austenitic welds. Research Approach: Evaluate phased arrays on unifornly-welded piping specimens. Apply best methods to non-uniform welds. Correlate acoustic responses as function of weld microstructures.

Energy Technology Data Exchange (ETDEWEB)

There is need of pressure surge analyses when valves or pumps are activated or piping systems fail (pipe rupture). Based on actual problems the influences of boundary conditions upon fluid simulation results are discussed. Hints concerning realistic dynamic analyses of piping systems are presented. Some of the simulations results are compared with measurements. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Developing DB system of piping reliability including the population data and service history of damaged piping for pilot power plant. Total weld counts of shop welds, field welds and welds for measuring instruments for 14 systems of Kori unit 3. Total weld counts of shop welds, field welds and welds for measuring instruments for 12 systems of Wolsung unit 2.

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys are being increasingly utilized in a variety of fields as an alternative material to organic materials and aluminum alloys, owing to excellent properties. Those include low density, and excellent damping properties. When compared to organic materials, furthermore, Mg alloy excels at recyclability, heat radiation, and electromagnetic-shielding. Though most of magnesium alloy products are manufactured through die-casting and thixo-molding at present, the demand for the expanding of magnesium wrought alloy market is increasing. Taking full advantage of a drawing technique and applying it to the conventional extruded pipe, we have developed a new type of magnesium alloy pipe. The strength of the developed pipe is significantly higher than that of the conventional one, either extruded or die-casting. Some of the excellent properties were obtained from fundamental tests performed with the developed ...

International Nuclear Information System (INIS)

In the WWER-440 reactor the primary piping consists of six horizontal loops going radially from the pressure vessel, each loop having a horizontal steam generator. In this reactor type the relatively long primary piping with many curved sections requires special attention in order to successfully eliminate the consequences of the design basis accident. Emergency supports are located in appropriate places to restrict the movements of the pipe. Under normal conditions there is a gap of some centimeters between the pipe and a support so that in the pipe can be deformed freely under changing loads. This paper deals with those energy-absorbing structures used at the Loviisa Nuclear Power Plant for protection against impact loading. Places and circumstances where energy-absorbing structures are employed are specified. Development and design of impact absorber elements are discussed and ...

Energy Technology Data Exchange (ETDEWEB)

An approximate analysis based on the virtual work technique, which was used to determine the effect of fluid velocity on the response frequency of a simply supported pipe, resulted in the following conclusions: (1) the critical fluid velocity at which the system becomes statically unstable is 129.5 ft/s; (2) the natural frequency of the pipe decreases as the fluid velocity increases; (3) higher flow rates increase the dynamic coupling of the system, making it much more susceptible to external excitation; (4) as the critical frequency approaches zero and the fluid velocity approaches the critical value, the amplitude becomes greater (though in an actual pipe, damping effects will limit the amplitude somewhat); and (5) the virtual work technique is a convenient method for approximating solutions to most non-linear vibration problems, giving results that are satisfactory for engineering-design purposes.

Energy Technology Data Exchange (ETDEWEB)

In this study, experiments were performed for pipe whip phenomena simulation. The analytical method was developed by combining several kinds of elements in ABAQUS computer code, standard version 5.2 . The transient analytical and the experimental results of the pipe whip test using 6 inch diameter pipe and U-shaped restraints are presented. It is shown that the adequate clearance decreases the restraint strains. As the overhang length increased, the maximum strain of restraints decreased. When the impact force increased, the maximum restraint strain increased slightly. The analytical models simulate the experimental impact phenomena very precisely, with slight conservatism. It is verified that the analytical method developed is very suitable to pipe whip phenomena analysis in nuclear power plants. 6 refs., 10 figs., 1 tab.

International Nuclear Information System (INIS)

The main sodium piping with a diameter of 16'' or 28 '' is being installed at the FFTF construction site starting in December 1974. The supplier and authority demarcations are: Combustion Engineering supplies the reactor vessel, guard vessel and adjoining pipes and uses the machine welding equipment ''Dimetrics''; for the piping system of the primary and secondary loops the pipes manufactured by Rollmet at HUICO, Pasco, were delivered and prefabricated there, as far as compatible with the installation. ''Astroarc'' welding machines are used by Bechtel for the piping prefabrication in the weld laboratory as well as on site at the construction site. Technical welding problems occurring during the course of the installation at the construction site and several during this time are described. At present 6 weld seams in the reactor and 14 weld seams in the secondary loop are accepted. ...

Energy Technology Data Exchange (ETDEWEB)

The US Nuclear Regulatory Commission is proposing to amend the regulations that currently require that the design basis for nuclear power plants include the postulation of dynamic effects from loss of coolant accidents up to and including the double-ended rupture of the largest pipe in the reactor coolant system. Proposed modifications would allow analyses to serve as a sufficient basis for excluding dynamic effects, including but not necessarily limited to pipe whip and jet impingement, associated with specific pipe ruptures. Only dynamic effects would be impacted; current design requirements for containment sizing and discharge capacity of emergency core cooling systems would remain unchanged. This report presents a detailed analysis of value-impact associated with the proposed amendment for PWR reactor coolant loop piping and for BWR recirculation loop piping. The effect of ...

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the application of a Computational Fluid Dynamics (CFD) code (FLUENT) to predict temperature and velocity profiles, and particle trajectories in an industrial fired by a low NO{sub x} pulverized coal swirl burner. The predictions of the code were compared to experimental measurements of gas temperature, particle size distribution, and particle velocities. The diagnostics employed were a suction pyrometer and a Particle Counter Sizer Velocimeter Probe (PCSV-P). Good agreement was found between the temperature predictions and the measurements. In situ particle size distributions were predicted accurately using the Baum and Street model with a swelling factor of zero. The numerical modeling indicated that the Type II flow issued from the burner could be transformed into Type III flow, by eliminating swirl from the primary air stream, which provided the preferred particle trajectories and increased the combustion efficiency.

British Library Electronic Table of Contents (United Kingdom)

A non-similar boundary layer analysis is presented to study the flow, heat and mass transfer characteristics of non-Darcian mixed convection of a non-Newtonian fluid from a vertical isothermal plate embedded in a homogeneous porous medium with the effect of Soret and Dufour and in the presence of either surface injection or suction. The value of the mixed-convection parameter lies between 0 and 1. In addition, the power-law model is used for non-Newtonian fluids with exponent n1 for dilatant fluids. Furthermore, the coordinates and dependent variables are transformed to yield computationally efficient numerical solutions that are valid over the entire range of mixed convection, from the pure forced-convection limit to the pure free-conve...

British Library Electronic Table of Contents (United Kingdom)

In this study, usage of a variable speed refrigeration system in latent heat thermal energy storage (LHTES) system is investigated to increase energy storage efficiency. Four different compressor speed control cases are compared to obtain a constant heat transfer fluid (HTF) temperature at the inlet of the energy storage tank. These control cases are (i) control with evaporation temperature, (ii) control with ethylene glycol temperature at the outlet section of evaporator, (iii) control with suction pressure of the compressor and (iv) on/off control. By means of the experimental analysis the best control strategy is obtained as control with Case (ii), in terms of stability of inlet temperature of heat transfer fluid, variations of energy efficiency of LHTES and coefficient of performance (...

Energy Technology Data Exchange (ETDEWEB)

A geothermal heat pump-assisted heating system is introduced into Changchun City and a survey is conducted to determine if the system may be popularized in this extremely cold region located in the northeastern part of China. In concrete terms, the hot water that circulates through the office building of Changchun Ground Heat Development Co., Ltd., is switched to hot water prepared by a geothermal heat pump. The test continued from December 2000 to March 2001. It is then concluded that heating by geothermal heat pumps will be fully serviceable to Changchun City. Implemented are (1) the shift from the coal fired boiler system to a geothermal heat pump system comprising 16 subterranean heat exchangers for the heating of the office building which is approximately 1000 m{sup 2} large, (2) long-term monitoring of the operating conditions, (3) measurement of subterranean heat exchanger thermal conductivity and subterranean temperature, and (4) the ...

Energy Technology Data Exchange (ETDEWEB)

Pipe whip tests or jet discharge tests have been performed at the Japan Atomic Energy Research Institute, which simulate the instantaneous circumferential guillotine break of primary coolant piping in nuclear power plants. The present paper describes the results of the pipe whip tests using test pipes of 4 inch diameter, under the BWR LOCA conditions, which were performed from 1979 to 1981. The tests were carried out at an initial pressure of about 6.8 MPa and an initial temperature of about 285/sup 0/C. The test pipe was 114.3 mm (4 in) in diameter, 8.6 mm in thickness and 4500 mm in length. The four pipe whip restraints used in the tests were the U-bar type of 8 mm in diameter and frabricated from Type 304 stainless steel. The experimental parameters were the clearance (30, 50 and 100 mm) and the overhang length (250, 400, 550 and 1000 mm). The main purpose of ...

Science.gov (United States)

The ability to mechanically reinforce an osteoporotic vertebral body could impede spinal compression fracture and the associated pain and complications. Previous studies have shown that reinforcement of fractured vertebrae with conventional acrylic cement can relieve symptoms and avoid further collapse. In this study, we explored the use of a carbonated apatite cement combined with a minimally invasive injection technique to improve the compressive mechanical properties of cadaveric vertebral bodies. After establishing the biomechanical characteristics of cement formulations intended to have appropriate viscosities, we evaluated the infiltration of the cements into thoracic vertebral bodies using a combined suction-injection technique. The energy-absorption capabilities of the reinforced vertebral bodies were then measured during axial compressive tests and compared with those of nonreinforced vertebrae. The ultimate compressive strength of the cement formulations ...

Energy Technology Data Exchange (ETDEWEB)

In the Energy Balance Analysis Model (Standard Review Plan (USNRC, 1981), Section 3.6.2, ''Determination of Rupture Locations and Dynamic Effects Associated with the Postulated Rupture of Piping''), time dependence is not considered, and a constant blowdown thrust force is assumed. This force includes an amplification factor of 1.1 to account for potential effects of rebound. Many of the assumptions used in establishing the acceptance criteria, as stated in the Standard Review Plan, were based on engineering judgment and logic intended to assure upper bound design rather than on a mechanistic assessment of actual pipe rupture phenomena and their effects. As a result of the current practice an exceedingly conservative design may be introduced. This report represents a parametric study of the amplification factor to account for rebound effects in the Energy Balance Method. Of the 71 distinct cases we chose for ...

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 ...

International Nuclear Information System (INIS)

This is a slide-based oral presentation given to the COG/IAEA: Fifth technical committee meeting on 'Exchange of operating experience of pressurized heavy water reactors' held in Mangalia, Romania on 7-10 September 1998. Since energization of Wolsung Unit 3 station service transformer on July 12, 1996 a line of initial test program was conducted as follows: 1. ILRT/SIT; 2. Pre-operational and Hot Functional testing with a Light Water and without Fuel in Systems; 3. Load D_2O in Moderator System; 4. Initial fuel loading; 5. Load D_2O in PHT System; 6. Hot Functional Testing with Heavy Water and Fuel in Systems; 7. Criticality and Low Power Physics Testing; 8. Power Ascension Test and, then finally, phase-D test; the plant acceptance test was accomplished after having a Mini-Overhaul to prepare for Commercial Operation. These documents contain not only both overall introduction of commissioning and the first TBN rolling and ...

Energy Technology Data Exchange (ETDEWEB)

This paper represents a parametric study of the amplification factor to account for rebound effects in the Energy Balance Method. Of the 66 distinct cases we chose for our parametric study, the amplification factor of 1.1 seems sufficient except in four borderline cases where the carbon steel pipes are small or have very small gaps between the pipes and the pipe whip restraints. We conclude that the amplification factor generally decreases as the parameters gap size, hinge-to-break distance and overhang increase.

Energy Technology Data Exchange (ETDEWEB)

This paper summarizes the investigation of horizontal direction drilling and the subsequent experimental installation of a natural gas network in a suburb of Paris, France. Three aspects of drilling were studied prior to implementation: (1) reliability of the technique and quality of pipelaying to ensure long-term supply main operation; (2) ability to assess the successfulness of the work by assessing preliminary conditions; and (3) economonic viability. Measurement of tensile stress on polyethylene pipe during pulling and comparative accelerated aging tests on scratched pipe were performed. In the implementation phase, 300 meters of pipe were laid daily, by using three machines simultaneously, at a cost comparable to that of conventional techniques.

Energy Technology Data Exchange (ETDEWEB)

Dynamic response of pipelines buried in a back-filled rectangular trench in a semi-infinite medium has been investigated. The pipelines are modeled as long cylindrical shells of small thickness. By using the boundary integral representation and finite element method, we have studied the three-dimensional response to account for either pane P or SV wave incident at an arbitrary angle to the pipe-axis. In this paper numerical results are presented for the normal displacements, displacements along pipe-axis, and the hoop stresses in the pipe wall. It is shown that the response depends critically on the back-filled material as well as on the directions of propagation of the incident waves.

Science.gov (United States)

Orchestration Layer. Service Delivery . Datacenter. Infrastructure. Systems call API. E2E automated. Automate service-levels. Analyze & ...

Energy Technology Data Exchange (ETDEWEB)

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Fault Tree, Event Tree, and Piping and Instrumentation Diagram (FEP) editors allow the user to graphically build and edit fault trees, and event trees, and piping and instrumentation diagrams (P and IDs). The software is designed to enable the independent use of the graphical-based editors found in the Integrated Reliability and Risk Assessment System (IRRAS). FEP is comprised of three separate editors (Fault Tree, Event Tree, and Piping and Instrumentation Diagram) and a utility module. This reference manual provides a screen-by-screen guide of the entire FEP System.

Science.gov (United States)

... 36 7 Corrugated Steel Pipe Concept Layout--Elevation ..... 37 viii ... revetment. 3. Land Use ... Corner modules and capping blocks are available. ...

Energy Technology Data Exchange (ETDEWEB)

Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and ...

Energy Technology Data Exchange (ETDEWEB)

In order to improve the working conditions for the operators of drilling rigs, the work area for handling of pipes and tubes is arranged on a main deck convered by a drill deck, which has openings closable by hatch cover panels. The derrick is enclosed in a cover, from which tunnels extend out over the drill deck and comprises lifting means for handling of pipes and tubes between the decks. The tunnels are connected to the cover of the derrick by raised enclosures permitting the swinging of pipes from a horizontal position in the tunnel to a vertical position in the derrick, and vice versa. There is a door, at least at one of the enclosures, permitting handling of especially long objects. Basically, the handling of pipes and tubes can be performed within areas fully protected from the weather.

Energy Technology Data Exchange (ETDEWEB)

Stochastic models for the simulation of global radiation are discussed. Thermal transients in the ground are analyzed. The performance of buried-pipe storage and a space heating system with long-term storage is described.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

The invention is a mechanism for retaining an electrical transmission line. In one embodiment of the invention it is a system for retaining an electrical transmission line within downhole components. The invention allows a transmission line to be attached to the internal diameter of drilling components that have a substantially uniform drilling diameter. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string, drill collars, heavy weight drill pipe, and jars. The system also includes a coaxial cable running between the first and second end of a drill pipe, the coaxial cable having a conductive tube and a conductive core within it. The invention allows the electrical transmission line to withstand the tension and compression of drill pipe during routine drilling cycles.

Energy Technology Data Exchange (ETDEWEB)

An apparatus for measuring the overall decontamination factors of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves ...

Energy Technology Data Exchange (ETDEWEB)

A design is proposed for forming the rear screen of a chamber firebox at the point of aerodynamic projection and a design for attaching the pipes of the aerodynamic projection using girders linked with the screen by hinges and movable connections.

Science.gov (United States)

Programs & Services Technical Resources Land Use Soils Water Snow Survey & Water Supply Water Management Water Quality Watersheds Wetlands Air Plants & Animals Energy Climate...

International Nuclear Information System (INIS)

During the last years one focus of German PWR safety analysis was boron dilution events with the potential of reactivity transients. Coolant with a low boron concentration could be collected in localized areas of the reactor coolant system e.g. by separation of borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux- condenser heat transfer after a small break loss of coolant accident with a limited availability of the emergency core cooling systems. The TUeV NORD SysTec was charged by German supervisory authorities with the assessment of the safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses shall demonstrate that boron dilution events cannot lead to recriticality of the core. Hence the boron concentration at the core inlet has to be determined. TUeV ...

Energy Technology Data Exchange (ETDEWEB)

This 7th edition reveals the progress in steam engineering and the great future potential of steam engineering applications. Pollution abatement and design experiences gained during the operation of existing plants, and experiences gained in waste incineration are of environmental relevance. Recent materials developments and knowledge, e.g. as regards pipes and fittings, have been making significant contributions to supercritical-steam efficiency improvements. Emphasis is also placed on automation, control engineering, water chemistry etc., and on regulations, licensing procedures, and the training of the staff of plants. (orig./KOW) [Deutsch] Die nunmehr vorliegende 7. Ausgabe zeigt den Fortschritt und das zukuenftig noch erhebliche Potential dieser Technik auf. Erfahrungen mit den nun schon seit Jahren laufenden Anlagen zur Schadstoffminderung, Konstruktion und Auslegung sowie Betriebserfahrungen zur thermischen Abfallverwertung sind ...

Energy Technology Data Exchange (ETDEWEB)

A borehole televiewer (BHTV) logging was conducted to investigate cracks in bored wells. The logging process shoots ultrasonic waves onto bore walls and utilizes reflection waves from the bore walls. If the bores are filled with muddy water, or the ultrasonic waves can pass through even if vinyl chloride tubes have been inserted after excavation, the state of the bore walls can be investigated in principle. Conventional optical scanners are, however, incapable of making this investigation. The BHTV logging can be used for identifying lithofacies from reflection intensities from bore walls (it depends on sound impedance of rocks), not to speak of finding cracks. As a result of making logging upon setting time windows from 105 to 145 {mu} sec in a bored well inserted with a vinyl chloride tube, cracks in the bore wall were identified clearly through the vinyl chloride tube. If the distance between the bore wall and the vinyl chloride tube becomes smaller, setting the ...

Energy Technology Data Exchange (ETDEWEB)

The upgrading of several 69 kV pipe-type cable feeders on the Potomac Electric Power Company (PEPCo) transmission cable system is discussed. The methods used for the ampacity calculation are described. The fluid circulation approach required to meet the feeder emergency load requirements are discussed. For the feeders that were in service for approximately 40 years, a system life evaluation was performed.

Energy Technology Data Exchange (ETDEWEB)

Through a comprehensive and aggressive research program Consolidated Edison Company of New York, Inc. (Con Edison) has designed, developed, and installed several new products to address the environmental impact of dielectric fluid from pipe-type cable systems. These include: On Line Leak Detection, Leak Location, Retractable Flow Direction Indicator, Full Stop Joints, and Transition Joints. This paper describes the application of the aforementioned products on the Con Edison underground transmission system.

Energy Technology Data Exchange (ETDEWEB)

The enhancement of longitudinal heat transfer by means of fluid pulsation in a pipe has been investigated analytically and numerically, including the transient state. The effects of pulsation amplitude, frequency, and pipe length on thermal properties such as effective thermal diffusivity and delay time are clarified. Their effects on numerical calculations are also presented and suggestions for efficient numerical calculations of this problem are made concerning the combination of parameters.

Energy Technology Data Exchange (ETDEWEB)

This book contains nine selections. Some of the titles are: High Heat-Flux, Forced-Convection Heat Transfer for Tubes with Twisted-Tape Inserts; Heat Transfer Augmentation by Interrupted Surfaces - Experimental Consideration; Turbulent Flow Heat Transfer from Externally Roughened Tubes in Axial Flow in Concentric Pipe Heat Exchangers; and Heat Transfer Enhancement of Turbulent Flow in Pipes with an Internal Circular Rib.

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows:In the current thermal-hydraulic system analysis codes using the two-fluid model, the empirical correlations that are based on the two-phase flow regimes and regime transition criteria are being employed as closure relations for the interfacial transfer terms. Due to its inherent shortcomings, however, such static correlations are inaccurate and present serious problems in the numerical analysis. In view of this, a new dynamic approach employing the interfacial area transport equation has been studied. The interfacial area transport equation dynamically models the two-phase flow regime transitions and predicts continuous change of the interfacial area concentration along the flow field. Hence, when employed in the thermal-hydraulic system analysis codes, it eliminates artificial bifurcations stemming from the use of the static flow regime transition criteria. Therefore, the interfacial area transport equation can make a leapfrog improvement in the ...

International Nuclear Information System (INIS)

The two-phase flow regime transition in a large diameter (I.D.=200mm) vertical pipe was experimentally investigated using a dual-sensor optical probe. The flow transitions from bubbly to chum without an intermediate slug flow regime as the air flow rate is increased. The transition boundaries developed for bubbly to slug flow in small diameter pipes are compared to the bubbly to chum flow transition of the present experiment. The bubbly to chum transition occurs at a void fraction of about 0.15 compared to 0.25 for bubbly to slug transition in small diameter pipes. The radial distribution of bubble diameter, bubble frequency, bubble velocity and local void fraction were obtained using a dual-sensor optical probe at different flow conditions. The Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of the bubble velocity and size are used to study the flow regime transition in the large diameter ...

International Nuclear Information System (INIS)

The interrelations between the factors causing the main effects on the primary circuit coolant flow rate distribution in the horizontal steam generator pipes in reactor facilities with the WWER type reactors under the modes with natural circulation are discussed. The criterion showing the presence or absence of coolant circulation reversal in bottom rows of the steam generator pipes is obtained. It is shown that large hydraulic non-uniformity in steam generator pipes operating in parallel under coolant natural circulation leads to decreasing the heat transfer surface efficiency under reactor facility emergency cooling, restricts its servicing capabilities. The circulation reverse in steam generator pipes under coolant natural circulation mode can give unfavourable effect on separate structural elements of the steam generators and as a result it can cause additional temperature strains in metal. The ...

Energy Technology Data Exchange (ETDEWEB)

Using electromatic field theory, a new method is developed for calculating alternating current in power cables installed in pipes of carbon steel (magnetic pipes). The technique for evaluating these losses is based on the method of images which replaces complicated distribution of currents in the system with a sequence of thin conductors. The method not only gives a mathematical framework for the solution of alternating current losses, but it also gives the underlying physical picture of effects contributing to these losses. Skin effect, proximity effect and losses due to the pipe are calculated separately. For the first time, the increase of losses in the conductors, when the cables are placed in a magetic pipe, are analyzed mathematically. Good agreement is obtained between the result of calculations and the experimentally determined ac-dc resistance ratios for pipe-type cables ...

Energy Technology Data Exchange (ETDEWEB)

Today`s nuclear power plants are marked by increasing needs for non-destructive inspection techniques in preventive maintenance programs. Additionally, it is becoming more important to evaluate residual stress which may be a key parameter for crack propagations in welded pipings. The authors have developed an ultrasonic velocity measurement method which obtains ultrasonic velocity changes by residual stress with a high accuracy. The ultrasonic velocity measurement is composed of three procedures. They are as follows. (1) Highly accurate propagation time measurements; (2) Pipe thickness correction; (3) Residual stress evaluation. The ultrasonic velocity measurements have been applied to the residual stress evaluation of carbon steel welded pipings. Destructive testing using stress strain gauges was done after the ultrasonic non-destructive evaluation of the residual stress. The experimental results verified that residual ...

International Nuclear Information System (INIS)

TRACI, a model based on the physical mechanisms governing the radon transport in unsaturated soils, has been developed to evaluate the radon flux density at Uranium Mill Tailings (UMT) covers surface. First, moisture contents in the soil, induced by weather conditions, are calculated. Then, radon concentrations in the air-filled pore space, and radon flux density at the soil surface, are deduced from a transport model which takes account for diffusion and convection in the pore space. To check the hypothesis used in TRACI and the efficiency of cover layers, an in situ study was launched in 1997 with the French uranium mining company, COGEMA. It consists of continuous measurements of moisture contents, suctions, radon concentrations at various depths inside an UMT cover, and flux density at its surface. The first analysis made on in situ observations shows that radon concentrations and flux density, calculated with a steady-state diffusion model using monthly ...

Energy Technology Data Exchange (ETDEWEB)

Lower cost painting flock-like in appearance and touch feeling was developed as a new surface softening method for automobile interior plastic molded parts. The base coat with the same color as piles mixed into a top coat was first painted on the surface of a plastic molded part after cleaning, and after the top coat with less pitch mixed with piles was painted on the wet base coat and dried by a heater, excess piles were removed with suction and air blowing to produce flock-like appearance. Nylon 66 of 0.4mm in length was used as piles, and mixed into the top coat by 8.0wt% in content. This painting method was applicable to even such parts as one with a complex configuration, and one impossible to set piles on it by conventional methods because of poor durability. As a certain amount of piles with different colors were mixed into the top coat, sprinkly colored appearance, unattainable by conventional methods, could be also produced. 1 ref., 13 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

The necessary conditions to design the methanol-fueled direct injection diesel engine with a reservoir type glow plug were cleared up from the points of view to prevent the air contamination and to use as an alternative oil for automotives, and as a result the good engine performance and emission characteristics could be obtained under the wide operating condition. The following facts were clarified: It is necessary to arrange the glow plug on the line of atomizing axis near the nozzle hole to ensure the ignitability under a wide operating condition. The reservoir type glow plug which reserves the premixed gas around the glow plug can shorten the ignition delay time and improve the combustion stability and the net thermal efficiency in the light load region. The combustion in the light load region was accelerated, NO{sub x} emission rate was suppressed and moreover, the net thermal efficiency and catalyst conversion rate were improved by applying an EGR(exhasut gas recirculation). The ...

Energy Technology Data Exchange (ETDEWEB)

The IPIRG-2 program was an international group program managed by the US NRC and funded by organizations from 15 nations. The emphasis of the IPIRG-2 program was the development of data to verify fracture analyses for cracked pipes and fittings subjected to dynamic/cyclic load histories typical of seismic events. The scope included: (1) the study of more complex dynamic/cyclic load histories, i.e., multi-frequency, variable amplitude, simulated seismic excitations, than those considered in the IPIRG-1 program, (2) crack sizes more typical of those considered in Leak-Before-Break (LBB) and in-service flaw evaluations, (3) through-wall-cracked pipe experiments which can be used to validate LBB-type fracture analyses, (4) cracks in and around pipe fittings, such as elbows, and (5) laboratory specimen and separate effect pipe experiments to provide better insight into the effects of dynamic and cyclic load ...

Energy Technology Data Exchange (ETDEWEB)

By tests about pipe failure under extreme bending, moment at cross sections affected by circumferential cracks, admissible strains for securing the integrity in the area of a flow link are indicated. These are 7% for austenic and ferritic materials in the undisturbed cross section. From d/t-ratios of 20 onwards the strains are limited by pipe bulging on the pressure-load side. In this connection, circumferential flaws do not have any influence on the behaviour on the strained side, when their expansion does not exceed the investigated limitis of <60 circumferential expansion and crack depth of 0,3 t. (orig.)

International Nuclear Information System (INIS)

The Argyle pipe occurring in the East Kimberley Province of Western Australia is a unique, highly-diamondiferous lamproite. Although it resembles other lamproites located in the West Kimberley Province with respect to its setting, structure, petrography and geochemistry, it is probably Proterozoic in age and hence substantially older than Tertiary occurrences of the West Kimberley Province. Rb-Sr measurements on whole rock and phlogopite samples from magmatic olivine-phlogopite lamproite, reveals a two point model age of 1126 +- 9 Ma for the Argyle pipe. This age is consistent with ages of other, similar volcanic igneous rocks occurring in several localities worldwide. The widespread occurrence of Proterozoic kimberlites and lamproites suggests that this was an important period of worldwide alkalic intrusive activity.

Energy Technology Data Exchange (ETDEWEB)

The ultrasonic inspection pig system was described as being under development. This system was said to adopt the unique wheel type ultrasonic sensor which does not need couplant. This pig was designed to detect external corrosion in long-distance pipelines without interruption of the gas service. The wall-thickness measurement performance test and the travel performance test of the inspection pig in the test line confirmed that these performances satisfied the development specifications. However, the effect induced by the inner surface properties of the pipe and the influence of the pipe`s performance over long distances and for a long period of time still needed to be verified in an actual gas pipeline, and while the pipeline was actually in service. Improvements to the prototype model of the inspection pig were expected to include combinations of inspection pigs, with increases in battery and memory capacities to permit them to cope with in ...

International Nuclear Information System (INIS)

Purpose: To flatten temperature distribution of coolant within a core. Constitution: The control device of the present invention is to vary reactivity of a fast breeder to control a reactor power. In general, the control device of this kind comprises a guide pipe arranged within the core and a control rod movable up and down within the guide pipe, and a coolant flows from bottom toward top within the guide pipe. Since a cooling flow rate has a margin, temperature of coolant outlet is extremely low as compared to a fuel assembly, and therefore temperature gradient in the vicinity of the top of the control rod becomes sharp to possibly impart thermal shock to the structural material. In the present invention, the flow passage of coolant is varied to thereby avoid outflow thereof into the core, thus flattening the temperature distribution of the coolant within the core. (Kamimura, M.).

International Nuclear Information System (INIS)

... hydrology norway water pollution pollution scandinavia surface waters

Energy Technology Data Exchange (ETDEWEB)

The properties of cast basalt and alumina are examined. The ways in which these materials have been used in applications in coal preparation plants, for example in bunker and pipe linings where abrasion and corrosion resistant materials are required, are discussed.

Energy Technology Data Exchange (ETDEWEB)

This paper describes radiography as one of the most efficient and cost effective methods for inspecting electric cabls. Details of one project in particular, i.e., the inspection of high-pressure, oil-filled, pipe-type cables (HPOF) are given. 2 refs.

Energy Technology Data Exchange (ETDEWEB)

In 1976, the US Department of Energy and New York State - ERDA granted a contract for the development of a +-600 kV dc underground transmission cable system looking to inevitable future requirements in the US for economic, high-capacity, long-distance underground transmission linking remote generating stations to metropolitan load centers. This project was comprehensive and dealt with three separate system components, i.e., cable, splice, and terminals. In each instance, for each component, development required an intensive R and D effort, focused on the following categories: insulating materials, model testing, design of full-scale prototype, manufacturer of prototype, and laboratory development testing. Insulating papers and oils were selected, and model studies performed, for both self-contained type and pipe type oil-filled cables. However, only the pipe cable design was finally designated for full-size cable manufacture and EHV laboratory ...

Energy Technology Data Exchange (ETDEWEB)

It was to be investigated why inexplicable cracking occurred in plain stainless austenitic steel pipes of heat exchangers in discrete sites of the inner surface exposed to acid even with anodic corrosion protection, and what countermeasures must be taken. The following materials were investigated: X 6 CrNiTi 18 10 and X 6 CrNiMoTi 17 12 2. The influence of mechanical vibrations on passive film formation and destruction was investigated in unconstrained pipes and pipes constrained at one end in conditions of anodic protection at frequencies of 0 to 160 Hz and temperatures of 98 to 130 degrees Centigrade in 98% sulphuric acid. The authors were unable to reconstruct the cracks observed in practical operation in anodically protected heat exchanger pipes of stainless austenitic steel. (orig./MM). 5 refs., 2 tabs., 71 figs.

Science.gov (United States)

The present study investigates the effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer enhancement in a pipe flow. The constant heat flux as thermal boundary condition was adopted in the thermally developed region. The present analytical results show the heat transfer enhancement over those of a shear rate-independent thermal conductivity fluid. The heat transfer coefficient ratio (h/h{sub 0}) linearly increase with the non-dimensional average velocity difference which is the product of the shear rate-dependence of the thermal conductivity and wall-shear rate.

British Library Electronic Table of Contents (United Kingdom)

Simplified strain-based fracture mechanics equations, established for external surface cracked pipelines subjected to an external bending load, are presented and used in probabilistic assessment of a pipeline girth weld. The model takes into account several parameters, such as variation in crack depth, crack length, internal pressure and material hardening. The critical strain from ductile tearing in the cracked pipeline is found by using the tangency criterion. The reliability problem is solved using first and second order reliability methods for different pipe dimensions and load levels.

Energy Technology Data Exchange (ETDEWEB)

A progress report is presented on development of the WIPS computer code, a special purpose code for analysis of whip and impact in nuclear power piping. The computer code and final report are expected to be complete in December 1981. This progress report is an incomplete version of the final report, representing approximately 40% of the volume of the final report. Some sections in the report are complete, some are partially complete, and others are omitted. The report is intended to inform prospective WIPS users of the procedures, theories, and documentation standards which will be used for the computer code and the final report.

Energy Technology Data Exchange (ETDEWEB)

Volume 2 of the water resources data for the 1992 water year for Oklahoma consists of record of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes or reservoirs; and water levels of ground-water well. The report contains discharge records for 136 gaging stations; stage and contents for 31 lakes or reservoirs; water quality for 50 gaging stations. Also included are 61 partial-record or miscellaneous streamflow stations and 28 ground-water sites.