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Sample records for blowdown

  1. Monodromy Substitutions and Rational Blowdowns

    CERN Document Server

    Endo, Hisaaki; van Horn-Morris, Jeremy

    2010-01-01

    We introduce several new families of relations in the mapping class groups of planar surfaces, each equating two products of right-handed Dehn twists. The interest of these relations lies in their geometric interpretation in terms of rational blowdowns of 4-manifolds, specifically via monodromy substitution in Lefschetz fibrations. The simplest example is the lantern relation, already shown by the first author and Gurtas to correspond to rational blowdown along a -4 sphere; here we give relations that extend that result to realize the "generalized" rational blowdowns of Fintushel-Stern and Park by monodromy subsitution, as well as several of the families of rational blowdowns discovered by Stipsicz-Szab\\'o-Wahl.

  2. PPOOLEX experiments with two parallel blowdown pipes

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2011-01-15

    This report summarizes the results of the experiments with two transparent blowdown pipes carried out with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through either one or two vertical transparent blowdown pipes to the condensation pool. Five experiments with one pipe and six with two parallel pipes were carried out. The main purpose of the experiments was to study loads caused by chugging (rapid condensation) while steam is discharged into the condensation pool filled with sub-cooled water. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. In the experiments the initial temperature of the condensation pool water varied from 12 deg. C to 55 deg. C, the steam flow rate from 40 g/s to 1 300 g/s and the temperature of incoming steam from 120 deg. C to 185 deg. C. In the experiments with only one transparent blowdown pipe chugging phenomenon didn't occur as intensified as in the preceding experiments carried out with a DN200 stainless steel pipe. With the steel blowdown pipe even 10 times higher pressure pulses were registered inside the pipe. Meanwhile, loads registered in the pool didn't indicate significant differences between the steel and polycarbonate pipe experiments. In the experiments with two transparent blowdown pipes, the steamwater interface moved almost synchronously up and down inside both pipes. Chugging was stronger than in the one pipe experiments and even two times higher loads were measured inside the pipes. The loads at the blowdown pipe outlet were approximately the same as in the one pipe cases. Other registered loads around the pool were about 50-100 % higher than with one pipe. The experiments with two parallel blowdown pipes gave contradictory results compared to the earlier studies dealing with chugging loads in case of multiple pipes. Contributing

  3. Optimization of Boiler Blowdown and Blowdown Heat Recovery in Textile Sector

    Directory of Open Access Journals (Sweden)

    Sunudas T

    2013-09-01

    Full Text Available Boilers are widely used in most of the processing industries like textile, for the heating applications. Surat is the one of the largest textile processing area in India. In textile industries coal is mainly used for the steam generation. In a textile industry normally a 4% of heat energy is wasted through blowdown. In the study conducted in steam boilers in textile industries in surat location, 1.5% of coal of total coal consumption is wasted in an industry by improper blowdwon. This thesis work aims to prevent the wastage in the coal use by optimizing the blowdown in the boiler and maximizing the recovery of heat wasting through blowdown.

  4. Construction of the blowdown and condensation loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon Kyung; Song, Chul Kyung; Cho, Seok; Chun, S. Y.; Chung, Moon Ki

    1997-12-01

    The blowdown and condensation loop (B and C loop) has been constructed to get experimental data for designing the safety depressurization system (SDS) and steam sparger which are considered to implement in the Korea Next Generation Reactor (KNGR). In this report, system description on the B and C loop is given in detail, which includes the drawings and technical specification of each component, instrumentation and control system, and the operational procedures and the results of the performance testing. (author). 7 refs., 11 tabs., 48 figs.

  5. PPOOLEX experiments with a modified blowdown pipe outlet

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2009-08-15

    This report summarizes the results of the experiments with a modified blowdown pipe outlet carried out with the PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a vertical DN200 blowdown pipe to the condensation pool. Four reference experiments with a straight pipe and ten with the Forsmark type collar were carried out. The main purpose of the experiment series was to study the effect of a blowdown pipe outlet collar design on loads caused by chugging phenomena (rapid condensation) while steam is discharged into the condensation pool. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. During the experiments the initial temperature level of the condensation pool water was either 20-25 or 50-55 deg. C. The steam flow rate varied from 400 to 1200 g/s and the temperature of incoming steam from 142 to 185 deg. C. In the experiments with 20-25 deg. C pool water, even 10 times higher pressure pulses were measured inside the blowdown pipe in the case of the straight pipe than with the collar. In this respect, the collar design worked as planned and removed the high pressure spikes from the blowdown pipe. Meanwhile, there seemed to be no suppressing effect on the loads due to the collar in the pool side in this temperature range. Registered loads in the pool were approximately in the same range (or even a little higher) with the collar as with the straight pipe. In the experiments with 50-55 deg. C pool water no high pressure pulses were measured inside the blowdown pipe either with the straight pipe or with the collar. In this case, more of the suppressing effect is probably due to the warmer pool water than due to the modified pipe outlet. It has been observed already in the earlier experiments with a straight pipe in the POOLEX and PPOOLEX facilities that warm pool water has a diminishing effect on

  6. Multiple blowdown pipe experiments with the PPOOLEX facility

    Energy Technology Data Exchange (ETDEWEB)

    Puustinen, M.; Laine, J.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2011-03-15

    This report summarizes the results of the experiments with two steel blowdown pipes carried out with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through the blowdown pipes to the condensation pool. The main purpose of the experiment series was to study chugging phenomena (rapid condensation) while steam is discharged through two parallel blowdown pipes into the condensation pool filled with sub-cooled water. Particularly, the aim was to study if the pipe material (polycarbonate) used in the earlier experiment series with two blowdown pipes has had an effect on the general chugging behaviour and measured loads. In the experiments the initial temperature of the pool water was 20 deg. C. The steam flow rate ranged from 220 g/s to 2 350 g/s and the temperature of incoming steam from 148 deg. C to 207 deg. C. The formation and collapse of steam bubbles and the movement of the steam/water interface inside the pipes was non-synchronous. There could be even a 70 ms time difference between the occurrences of steam bubble collapses at the outlets of the two pipes. There was no clear pattern in which pipe the steam bubble first starts to collapse. Several successive bubbles could collapse first in either pipe but then the order changed for a single or several cycles. High pressure loads were measured inside the blowdown pipes due to rapid condensation of the steam volumes in the pipes and resulting water hammer effects. The loads seemed to be higher in pipe 1 than in pipe 2. An explanation for this could be a possible unequal distribution of steam flow between the two pipes. The pipe material has an effect on the condensation phenomena inside the blowdown pipes. A huge difference in the measured pressure curves inside the pipes could be observed compared to the experiments with the polycarbonate pipes. With the same test conditions the amplitude of the

  7. Condensation pool experiments with steam using DN200 blowdown pipe

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M. [Lappeenranta Univ. of Technology (Finland)

    2005-08-01

    This report summarizes the results of the condensation pool experiments with steam using a DN200 blowdown pipe. Altogether five experiment series, each consisting of several steam blows, were carried out in December 2004 with a scaled-down test facility designed and constructed at Lappeenranta University of Technology. The main purpose of the experiments was to increase the understanding of different phenomena in the condensation pool during steam discharge. (au)

  8. Increased Frequency of Large Blowdown Formation in Years With Hotter Dry Seasons in the Northwestern Amazon

    Science.gov (United States)

    Rifai, S. W.; Anderson, L. O.; Bohlman, S.

    2015-12-01

    Blowdowns, which are large tree mortality events caused by downbursts, create large pulses of carbon emissions in the short term and alter successional dynamics and species composition of forests, thus affecting long term biogeochemical cycling of tropical forests. Changing climate, especially increasing temperatures and frequency of extreme climate events, may cause changes in the frequency of blowdowns, but there has been little spatiotemporal analysis to associate the interannual variation in the frequency of blowdowns with annual climate parameters. We mapped blowdowns greater than 25 ha using a time series of Landsat images from 1984-2012 in the northwestern Amazon to estimate the annual size distribution of these blowdowns. The difference in forest area affected by blowdowns between the years with the highest and lowest blowdown activity were on the order of 10 - 30 times greater depending on location. Spatially, we found the probability of large blowdowns to be higher in regions with higher annual rainfall. Temporally, we found a positive correlation between the probability of large blowdown events and maximum dry season air temperature (R2 = 0.1-0.46). Mean and maximum blowdown size also increased with maximum dry season air temperature. The strength of these relationships varied between scene locations which may be related to cloud cover obscuring the land surface in the satellite images, or biophysical characteristics of the sites. Potentially, elevated dry season temperatures during the transition from the dry season to the wet season (October - December) may exacerbate atmospheric instabilities, which promote downburst occurrences. Most global circulation models predict dry season air temperatures to increase 2-5 ℃ in the northwestern Amazon by 2050. Should the blowdown disturbance regime continue increasing with elevated dry season temperatures, the northwestern Amazon is likely to experience more catastrophic tree mortality events which has direct

  9. PIV measurement at the blowdown pipe outlet. [Particle Image Velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Puustinen, M.; Laine, J.; Raesaenen, A.; Pyy, L.; Telkkae, J. [Lappeenranta Univ. of Technology, Lappeenranta (Finland)

    2013-04-15

    This report summarizes the findings of the PIV measurement tests carried out in January - February 2013 with the scaled down PPOOLEX test facility at LUT. The main objective of the tests was to find out the operational limits of the PIV system regarding suitable test conditions and correct values of different adjustable PIV parameters. An additional objective was to gather CFD grade data for verification/validation of numerical models. Both water and steam injection tests were carried out. PIV measurements with cold water injection succeeded well. Raw images were of high quality, averaging over the whole measurement period could be done and flow fields close to the blowdown pipe outlet could be determined. In the warm water injection cases the obtained averaged velocity field images were harder to interpret, especially if the blowdown pipe was also filled with warm water in the beginning of the measurement period. The absolute values of the velocity vectors seemed to be smaller than in the cold water injection cases. With very small steam flow rates the steam/water interface was inside the blowdown pipe and quite stable in nature. The raw images were of good quality but due to some fluctuation in the velocity field averaging of the velocity images over the whole measured period couldn't be done. Condensation of steam in the vicinity of the pipe exit probably caused these fluctuations. A constant outflow was usually followed by a constant inflow towards the pipe exit. Vector field images corresponding to a certain phase of the test could be extracted and averaged but this would require a very careful analysis so that the images could be correctly categorized. With higher steam flow rates rapid condensation of large steam bubbles created small gas bubbles which were in front of the measurement area of the PIV system. They disturbed the measurements by reflecting laser light like seeding particles and therefore the raw images were of poor quality and they couldn

  10. A Hydraulic Blowdown Servo System For Launch Vehicle

    Science.gov (United States)

    Chen, Anping; Deng, Tao

    2016-07-01

    This paper introduced a hydraulic blowdown servo system developed for a solid launch vehicle of the family of Chinese Long March Vehicles. It's the thrust vector control (TVC) system for the first stage. This system is a cold gas blowdown hydraulic servo system and consist of gas vessel, hydraulic reservoir, servo actuator, digital control unit (DCU), electric explosion valve, and pressure regulator etc. A brief description of the main assemblies and characteristics follows. a) Gas vessel is a resin/carbon fiber composite over wrapped pressure vessel with a titanium liner, The volume of the vessel is about 30 liters. b) Hydraulic reservoir is a titanium alloy piston type reservoir with a magnetostrictive sensor as the fluid level indicator. The volume of the reservoir is about 30 liters. c) Servo actuator is a equal area linear piston actuator with a 2-stage low null leakage servo valve and a linear variable differential transducer (LVDT) feedback the piston position, Its stall force is about 120kN. d) Digital control unit (DCU) is a compact digital controller based on digital signal processor (DSP), and deployed dual redundant 1553B digital busses to communicate with the on board computer. e) Electric explosion valve is a normally closed valve to confine the high pressure helium gas. f) Pressure regulator is a spring-loaded poppet pressure valve, and regulates the gas pressure from about 60MPa to about 24MPa. g) The whole system is mounted in the aft skirt of the vehicle. h) This system delivers approximately 40kW hydraulic power, by contrast, the total mass is less than 190kg. the power mass ratio is about 0.21. Have finished the development and the system test. Bench and motor static firing tests verified that all of the performances have met the design requirements. This servo system is complaint to use of the solid launch vehicle.

  11. PWR safety/relief valve blowdown analysis experience

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.Z.; Chou, L.Y.; Yang, S.H. (Gilbert/Commonwealth Engineers and Consultants, Reading, PA (USA). Speciality Engineering Dept.)

    1982-10-01

    The paper describes the difficulties encountered in analyzing a PWR primary loop pressurizer safety relief valve and power operated relief valve discharge system, as well as their resolution. The experience is based on the use of RELAP5/MOD1 and TPIPE computer programs as the tools for fluid transient analysis and piping dynamic analysis, respectively. General approaches for generating forcing functions from thermal fluid analysis solution to be used in the dynamic analysis of piping are reviewed. The paper demonstrates that the 'acceleration or wave force' method may have numerical difficulties leading to unrealistic, large amplitude, highly oscillatory forcing functions in the vicinity of severe flow area discontinuities or choking junctions when low temperature loop seal water is discharged. To avoid this problem, an alternate computational method based on the direct force method may be used. The simplicity and superiority in numerical stability of the forcing function computation method as well as its drawbacks are discussed. Additionally, RELAP modeling for piping, valve, reducer, and sparger is discussed. The effects of loop seal temperature on SRV and PORV discharge line blowdown forces, pressure and temperature distributions are examined. Finally, the effects of including support stiffness and support eccentricity in piping analysis models, method and modeling relief tank connections, minimization of tank nozzle loads, use of damping factors, and selection of solution time steps are discussed.

  12. Results of the first nuclear blowdown test on single fuel rods (LOC-11 Series in PBF)

    Energy Technology Data Exchange (ETDEWEB)

    Larson, J.R.; Evans, D.R.; McCardell, R.K.

    1978-01-01

    This paper presents results of the first nuclear blowdown tests (LOC-11A, LOC-11B, LOC-11C) ever conducted. The Loss-of-Coolant Accident (LOCA) Test Series is being conducted in the Power Burst Facility (PBF) reactor at the Idaho National Engineering Laboratory, near Idaho Falls, Idaho, for the Nuclear Regulatory Commission. The objective of the LOC-11 tests was to obtain data on the behavior of pressurized and unpressurized rods when exposed to a blowdown similar to that expected in a pressurized water reactor (PWR) during a hypothesized double-ended cold-leg break. The data are being used for the development and verification of analytical models that are used to predict coolant and fuel rod pressure during a LOCA in a PWR.

  13. Singular and interactive effects of blowdown, salvage logging, and wildfire in sub-boreal pine systems

    Science.gov (United States)

    D'Amato, A.W.; Fraver, S.; Palik, B.J.; Bradford, J.B.; Patty, L.

    2011-01-01

    The role of disturbance in structuring vegetation is widely recognized; however, we are only beginning to understand the effects of multiple interacting disturbances on ecosystem recovery and development. Of particular interest is the impact of post-disturbance management interventions, particularly in light of the global controversy surrounding the effects of salvage logging on forest ecosystem recovery. Studies of salvage logging impacts have focused on the effects of post-disturbance salvage logging within the context of a single natural disturbance event. There have been no formal evaluations of how these effects may differ when followed in short sequence by a second, high severity natural disturbance. To evaluate the impact of this management practice within the context of multiple disturbances, we examined the structural and woody plant community responses of sub-boreal Pinus banksiana systems to a rapid sequence of disturbances. Specifically, we compared responses to Blowdown (B), Fire (F), Blowdown-Fire, and Blowdown-Salvage-Fire (BSF) and compared these to undisturbed control (C) stands. Comparisons between BF and BSF indicated that the primary effect of salvage logging was a decrease in the abundance of structural legacies, such as downed woody debris and snags. Both of these compound disturbance sequences (BF and BSF), resulted in similar woody plant communities, largely dominated by Populus tremuloides; however, there was greater homogeneity in community composition in salvage logged areas. Areas experiencing solely fire (F stands) were dominated by P. banksiana regeneration, and blowdown areas (B stands) were largely characterized by regeneration from shade tolerant conifer species. Our results suggest that salvage logging impacts on woody plant communities are diminished when followed by a second high severity disturbance; however, impacts on structural legacies persist. Provisions for the retention of snags, downed logs, and surviving trees as part

  14. MELCOR 1.8.3 assessment: GE large vessel blowdown and level swell experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kmetyk, L.N.

    1994-07-01

    MELCOR is a fully integrated, engineering-level computer code, being developed at Sandia National Laboratories for the USNRC, that models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRS. As part of an ongoing assessment program, the MELCOR computer code has been used to analyze a series of blowdown tests performed in the early 1980s at General Electric. The GE large vessel blowdown and level swell experiments are a set of primary system thermal/hydraulic separate effects tests studying the level swell phenomenon for BWR transients and LOCAS; analysis of these GE tests is intended to validate the new implicit bubble separation algorithm added since the release of MELCOR 1.8.2. Basecase MELCOR results are compared to test data, and a number of sensitivity studies on input modelling parameters and options have been done. MELCOR results for these experiments also are compared to MAAP and TRAC-B qualification analyses for the same tests. Time-step and machine-dependency calculations were done to identify whether any numeric effects exist in our GE large vessel blowdown and level swell assessment analyses.

  15. Experiments and analytical studies related to blowdown and containment thermal hydraulics on CSF

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Anu, E-mail: adutta@barc.gov.in; Thangamani, I.; Shanware, V.M.; Rao, K.S.; Gera, B.; Ravi Kiran, A.; Goyal, P.; Verma, Vishnu; Sharma, P.K.; Agrawal, M.K.; Ganju, S.; Singh, R.K.

    2015-12-01

    Highlights: • Blowdown and containment thermal hydraulics experiments conducted in CSF. • RELAP5, ASTEC and CONTRAN codes used for analysis. • Containment peak pressure and temp predicted close to experimental values. • CONTRAN and ASTEC codes predict early containment depressurization. • Numerical procedure, benchmarked for loss of coolant accident in nuclear reactors. - Abstract: Containment Studies Facility (CSF) is volumetrically scaled down model of Indian Pressurized Heavy Water Reactor (IPHWR) containment for simulating LOCA/MSLB conditions which consists of concrete containment model (CM) and Primary Heat Transport Model (PHTM) vessel. Blowdown experiments at different initial vessel pressure conditions were recently conducted at CSF and the vessel and containment parameters such as pressure, temperature and level transients have been recorded during the experiments. The experimental results have been used for benchmarking of numerical procedure adopted for evaluating LOCA/MSLB conditions in nuclear containment. The numerical procedure involves simulation of blowdown phenomena using RELAP5 code for evaluating mass and energy discharge rates, which are then used for calculating containment pressure–temperature transients using ASTEC and in-house CONTRAN codes. Predictions of major parameters of vessel and containment model were found to be in good agreement with that of experimental data. In containment thermal hydraulic calculations, condensation heat transfer coefficient affects the containment pressure–temperature transients. Various empirical condensation models like Tagami, Uchida and Diffusion models have been incorporated in CONTRAN code and suitable condensation model has been identified for which predicted pressure values are close to the experimental one. The details of the experimental and analytical studies conducted are presented in this paper.

  16. Technical support to the Nuclear Regulatory Commission for the boiling water reactor blowdown heat transfer program

    Energy Technology Data Exchange (ETDEWEB)

    Rice, R.E.

    1976-09-01

    Results are presented of studies conducted by Aerojet Nuclear Company (ANC) in FY 1975 to support the Nuclear Regulatory Commission (NRC) on the boiling water reactor blowdown heat transfer (BWR-BDHT) program. The support provided by ANC is that of an independent assessor of the program to ensure that the data obtained are adequate for verification of analytical models used for predicting reactor response to a postulated loss-of-coolant accident. The support included reviews of program plans, objectives, measurements, and actual data. Additional activity included analysis of experimental system performance and evaluation of the RELAP4 computer code as applied to the experiments.

  17. Assessment of SWBR safety-relief valve discharge line dynamic loads due to steam blowdown

    Energy Technology Data Exchange (ETDEWEB)

    Spoelstra, S.; Stoop, P.M. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Dijk, A.B. van [Stork Nucon BV (Netherlands)

    1997-06-01

    The Safety/Relief Valve Discharge Lines of the SBWR nuclear power plant are subject to dynamic loads due to steam blowdown after rapid opening of the Safety/Relief Valves. This paper describes the calculation of the thermal-hydraulic loads exerted on the piping system and the calculation of the resulting pipe stresses. These calculations have been performed using the CHARME and PS+CAEPIPE computer programs respectively. The calculated pipe stresses have been combined with the ones resulting from dead weight and thermal expansion and compared with ASME III criteria. (orig.).

  18. Time-dependent measurement of base pressure in a blowdown tunnel with varying unit Reynolds number

    Science.gov (United States)

    Kangovi, S.; Rao, D. M.

    1978-01-01

    An operational characteristic of blowdown-type of wind tunnels is the drop in the stagnation temperature with time and the accompanying change in the test-section unit Reynolds number at constant stagnation pressure and Mach number. This apparent disadvantage can be turned to advantage in some cases where a Reynolds number scan is desired in order to study the effect of unit Reynolds number variation on a particular viscous flow phenomenon. This note presents such an instance arising from recent investigations on base pressure at transonic speeds conducted in the NAL 1-ft tunnel.

  19. PPOOLEX experiments on the dynamics of free water surface in the blowdown pipe

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M.; Raesaenen, A. [Lappeenranta Univ. of Technology, Lappeenranta (Finland)

    2013-04-15

    This report summarizes the results of the thermal stratification and mixing experiments carried out with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through the vertical DN200 blowdown pipe to the condensation pool filled with sub-cooled water. The main objective of the experiments was to obtain verification data for the development of the Effective Momentum Source (EMS) and Effective Heat Source (EHS) models to be implemented in GOTHIC code by KTH. A detailed test matrix and procedure put together on the basis of pre-test calculations was provided by KTH before the experiments. Altogether six experiments were carried out. The experiments consisted of a small steam flow rate stratification period and of a higher flow rate mixing period. The dry well structures were heated up to approximately 130 deg. C before the stratification period was initiated. The initial water bulk temperature in the condensation pool was 13-16 deg. C. During the low steam flow rate (85-105 g/s) period steam condensed mainly inside the blowdown pipe. As a result temperatures remained constant below the blowdown pipe outlet while they increased towards the pool surface layers indicating strong thermal stratification of the wet well pool water. In the end of the stratification period the temperature difference between the pool bottom and surface was 15-30 deg. C depending on the test parameters and the duration of the low flow rate period. In the beginning of the mixing phase the steam flow rate was increased rapidly to 300-425 g/s to mix the pool water totally. Depending on the used steam flow rate and initial pool water temperature it took 150-500 s to achieve total mixing. If the test was continued long enough the water pool began to stratify again after the water bulk temperature had reached {approx}50 deg. C despite of steam mass flux belonging to the chugging region

  20. Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L. [Inst. of Material Engineering, Ostrava (Switzerland)

    1995-12-31

    After modification of Dukovany NPP steam generator (SG) feedwater system, the increased concentration of minerals was measured in the cold leg of modified SG. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators has focused the attention to the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of the flow distribution in the secondary side of SG was developed.

  1. Vent sizing: analysis of the blowdown of a hybrid non tempered system.

    Science.gov (United States)

    Véchot, Luc; Minko, Wilfried; Bigot, Jean-Pierre; Kazmierczak, Marc; Vicot, Patricia

    2011-07-15

    The runaway and blowdown of a non tempered hybrid chemical system (30% cumene hydroperoxide) exposed to an external heat input was investigated using a 0.1l scale tool. The maximum temperature and the maximum temperature rise rate were showed to be sensitive to the vent size. An Antoine type correlation between the maximum temperatures and pressures was observed. These resulted from the presence of vapour, mainly generated by the reaction products. Increasing the initial filling ratio resulted in an earlier vent opening but did not have a significant influence on the blow-down. Three types of mass venting behaviour were observed, when changing the vent area to volume ratio (A/V): • for large A/V, two-phase venting occurred from the vent opening until the end of the second pressure peak; • for medium A/V, two-phase venting occurred before and after the turnaround. The data seem to indicate that gas only venting occurred at turn-around; • for low A/V, two-phase venting was observed only after the second pressure peak. Two-phase venting after the second pressure peak probably results from the boiling of the hot reaction products at low pressure.

  2. Development of the Variable Atmosphere Testing Facility for Blow-Down Analysis of the Mars Hopper Prototype

    Energy Technology Data Exchange (ETDEWEB)

    Nathan D. Jerred; Robert C. O' Brien; Steven D. Howe; James E. O' Brien

    2013-02-01

    Recent developments at the Center for Space Nuclear Research (CSNR) on a Martian exploration probe have lead to the assembly of a multi-functional variable atmosphere testing facility (VATF). The VATF has been assembled to perform transient blow-down analysis of a radioisotope thermal rocket (RTR) concept that has been proposed for the Mars Hopper; a long-lived, long-ranged mobile platform for the Martian surface. This study discusses the current state of the VATF as well as recent blow-down testing performed on a laboratory-scale prototype of the Mars Hopper. The VATF allows for the simulation of Mars ambient conditions within the pressure vessel as well as to safely perform blow-down tests through the prototype using CO2 gas; the proposed propellant for the Mars Hopper. Empirical data gathered will lead to a better understanding of CO2 behavior and will provide validation of simulation models. Additionally, the potential of the VATF to test varying propulsion system designs has been recognized. In addition to being able to simulate varying atmospheres and blow-down gases for the RTR, it can be fitted to perform high temperature hydrogen testing of fuel elements for nuclear thermal propulsion.

  3. Performance of an Exhaust-Gas "Blowdown" Turbine on a Nine-Cylinder Radial Engine

    Science.gov (United States)

    1944-12-01

    operation of a blowiown turbina predicted that the power output pmax at tho optimum turbine spaed is given by a relation of the form 55° Pffl Htf> e ’max...restriction than the ’.’right 1820-0 engine used for the faints of references 1 and h or that the blowdown turbina exerts a favorable suction effect during

  4. Feasibility study for electron beam and laser Raman non-intrusive diagnostic measurements in hypersonic blowdown wind tunnels

    Science.gov (United States)

    Powell, Homer M.; Ventrice, Carl A.; Yanta, William; Hedlund, Eric; Moyers, Richard L.

    Calculations based upon density measurements are presented for assessing the feasibility of electron beam and laser Raman flow diagnostic techniques for hypersonic blowdown wind tunnels of the Naval-Surface-Weapons-Center class. It is concluded that the electron beam technique is applicable only for flow visualization purposes, even at the low end of the test envelope.

  5. Singular and combined effects of blowdown, salvage logging, and wildfire on forest floor and soil mercury pools.

    Science.gov (United States)

    Mitchell, Carl P J; Kolka, Randall K; Fraver, Shawn

    2012-08-07

    A number of factors influence the amount of mercury (Hg) in forest floors and soils, including deposition, volatile emission, leaching, and disturbances such as fire. Currently the impact on soil Hg pools from other widespread forest disturbances such as blowdown and management practices like salvage logging are unknown. Moreover, ecological and biogeochemical responses to disturbances are generally investigated within a single-disturbance context, with little currently known about the impact of multiple disturbances occurring in rapid succession. In this study we capitalize on a combination of blowdown, salvage logging and fire events in the sub-boreal region of northern Minnesota to assess both the singular and combined effects of these disturbances on forest floor and soil total Hg concentrations and pools. Although none of the disturbance combinations affected Hg in mineral soil, we did observe significant effects on both Hg concentrations and pools in the forest floor. Blowdown increased the mean Hg pool in the forest floor by 0.76 mg Hg m(-2) (223%). Salvage logging following blowdown created conditions leading to a significantly more severe forest floor burn during wildfire, which significantly enhanced Hg emission. This sequence of combined events resulted in a mean loss of approximately 0.42 mg Hg m(-2) (68% of pool) from the forest floor, after conservatively accounting for potential losses via enhanced soil leaching and volatile emissions between the disturbance and sampling dates. Fire alone or blowdown followed by fire did not significantly affect the total Hg concentrations or pools in the forest floor. Overall, unexpected consequences for soil Hg accumulation and by extension, atmospheric Hg emission and risk to aquatic biota, may result when combined impacts are considered in addition to singular forest floor and soil disturbances.

  6. A Blowdown Cryogenic Cavitation Tunnel and CFD Treatment for Flow Visualization around a Foil

    Institute of Scientific and Technical Information of China (English)

    Yutaka ITO; Kazuya SAWASAKI; Naoki TANI; Takao NAGASAKI; Toshio NAGASHIMA

    2005-01-01

    Cavitation is one of the major problems in the development of rocket engines. There have been few experimental studies to visualize cryogenic foil cavitation. Therefore a new cryogenic cavitation tunnel of blowdown type was built. The foil shape is "plano-convex". This profile was chosen because of simplicity, but also of being similar to the one for a rocket inducer impeller. Working fluids were water at room temperature,hot water and liquid nitrogen. In case of Angle of Attack (AOA)=8°, periodical cavity departure was observed in the experiments of both water at 90℃ and nitrogen at -190℃ under the same velocity 10 m/sec and the same cavitation number 0.7. The frequencies were observed to be 110 and 90 Hz, respectively, and almost coincided with those of vortex shedding from the foil. Temperature depression due to the thermodynamic effect was confirmed in both experiment and simulation especially in the cryogenic cavitation.

  7. Calculation of sample problems related to two-phase flow blowdown transients in pressure relief piping of a PWR pressurizer

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y.W.; Wiedermann, A.H.

    1984-02-01

    A method was published, based on the integral method of characteristics, by which the junction and boundary conditions needed in computation of a flow in a piping network can be accurately formulated. The method for the junction and boundary conditions formulation together with the two-step Lax-Wendroff scheme are used in a computer program; the program in turn, is used here in calculating sample problems related to the blowdown transient of a two-phase flow in the piping network downstream of a PWR pressurizer. Independent, nearly exact analytical solutions also are obtained for the sample problems. Comparison of the results obtained by the hybrid numerical technique with the analytical solutions showed generally good agreement. The good numerical accuracy shown by the results of our scheme suggest that the hybrid numerical technique is suitable for both benchmark and design calculations of PWR pressurizer blowdown transients.

  8. Electromembrane recycling of highly mineralized alkaline blowdown water from evaporative water treatment plants at thermal power stations

    Science.gov (United States)

    Chichirova, N. D.; Chichirov, A. A.; Lyapin, A. I.; Minibaev, A. I.; Silov, I. Yu.; Tolmachev, L. I.

    2016-12-01

    Thermal power stations (TPS) are the main source of highly mineralized effluents affecting the environment. An analysis of their water systems demonstrates that alkaline effluents prevail at TPSs. Extraction of an alkali from highly mineralized effluents can make the recycling of effluents economically feasible. A method is proposed of electromembrane recycling of liquid alkaline highly mineralized wastes from TPSs. The process includes electromembrane apparatuses of two types, namely, a diffusion dialysis extractor (DDE) intended for extraction of the alkali from a highly mineralized solution having a complex composition and an electrodialysis concentrator for increasing the concentration of the extracted solution to a value suitable for use in water treatment plants at TPSs. For implementation of the first process (i.e. the extraction of alkali from alkaline-salt solution) various membranes from various manufacturers were studied: CM-PAD and AM-PAD (Ralex, Czechia), MK-40, MA-40, MA-41, MA-414, and MB-2 (OOO OKhK "Shchekinoazot", Russia), AR103-QDF and CR61-CMP (Ionies Inc., USA). The experiments demonstrate that the acceptable degree of separation of the alkali and the salt is achieved in a pair of cation-exchange membranes with the efficiency of separation being higher without an electric field. The highest efficiency was attained with Russian-made membranes (MK-40, OOO OKhK "Shchekinoazot"). A full scale experiment on recycling of highly-mineralized blowdown water from the evaporating water treatment system at the Kazan cogeneration power station No. 3 (TETs-3) was performed in a pilot unit consisting of two electromembrane apparatuses made by UAB "Membraninės Technologijos LT". In the experiments every ton of blowdown water yielded 0.1 t of concentrated alkaline solution with an alkali content of up to 4 wt % and 0.9 t of the softened salt solution suitable for the reuse in the TPS cycle. The power rate is 6 kWh / ton of blowdown water.

  9. Modification of blowdown heat transfer models for RELAP5-3D in accordance with appendix K of 10CFR50

    Energy Technology Data Exchange (ETDEWEB)

    Chin-Jang, Chang; Liang, T.K.S. [Nuclear Engineering Div. Institute of Nuclear Energy Research, Lung-Tan, Taiwan (China); Huan-Jen, Hung; Wang, L.C. [Power Research Institute, Taiwan Power Company (China)

    2001-07-01

    The objective of this paper is to implement the blowdown heat transfer models accepted by Appendix K of 10CFR50 into RELAP5-3D and to rename it as RELAP5-3D/K. Modifications of critical heat flux (CHF) model, post-CHF model, and the heat transfer logic for nucleate and transition boiling lockout are included. Also the assessments against separate-effect experiments were evaluated for RELAP 5-3D/K. From calculation results, the conservative predictions of surface peak temperatures using RELAP5-3D/K are obtained. It demonstrated that the blowdown heat transfer models were successfully modified and implemented into RELAP5-3D in accordance with Appendix K of 10CFR50. (authors)

  10. Statistical analysis of the blowdown phase of a loss-of-coolant accident in a pressurized water reactor as calculated by RELAP4/MOD6

    Energy Technology Data Exchange (ETDEWEB)

    Berman, M.; Byers, R.K.; Steck, G.P.

    1979-01-01

    A statistical study is presented of the blowdown phase of a design basis accident (double-ended cold leg guillotine break) in the Zion pressurized water reactor. The response surface method was employed to generate a polynomial approximation of the peak clad temperatures calculated by RELAP4/MOD6. The nodalization was a modification of the RELAP model of Zion developed in the BE/EM study. Twenty one variables were initially selected for the study. These variables, their ranges and distributions resulted from the best engineering judgement of NRC, Sandia, INFL, and other interested and knowledgeable investigators.

  11. Evaluation of SG blowdown demineralizer performance by replacement of ammonia with ethanolamine as a PWR secondary pH control agent

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, I.H. [Department of Materials and Chemical Engineering, Soonchunhyang Univ. (Korea, Republic of); Yim, S.J. [Operation Management Team, Korea Hydro and Nuclear Power Co. Ltd., Seoul (Korea, Republic of)

    2002-07-01

    Four Korean PWR plants have adopted ethanolamine (ETA) as a secondary pH control agent to increase the pH at the liquid phase, which raises the pH in the SG blowdown system. The run time of the SG blowdown demineralizer can be reduced by the increased number of ionic chemical species primarily due to ETA. Contrary to the possible prevention of SG degradation, the replacement of ammonia with ETA results in the water chemistry difficulties and more frequent generation of spent resin. A comprehensive experimental data set for binary, ternary, quaternary, and quinary cation and anion adsorption was developed from small-volume batch tests at total cation or anion concentrations of 0.01 and 0.05 N to obtain the selectivity coefficients of many cations and anions normally present in the PWR secondary system water. In addition, the kinetic study using the bench-scale column was performed to examine the breakthrough point of an ion and to calculate the ratio of inlet to outlet concentration at the column, so called Decontamination Factor, in the different background electrolyte. The batch equilibrium tests indicated that the ion selectivity is higher for an ion of higher valence and is not uniform in the different composition and ionic strength. The preference of an ion on ion exchange resin rather tends to be lower with higher ionic strength. The leakage of an ion from the ion exchange column is not also uniform in time in the various composition and total concentration. Therefore the ion selectivity and breakthrough time are different in ammonia and ethanolamine background electrolytes. The run time of SG blowdown demineralizer can be shorter than it can be expected due to the elevated ionic strength as well as the increased dissolved solids. The quantitative run time can be estimated by such ion exchange models as semi-empirical mass action and surface complexation models. The demineralizer can be used longer by increasing the ratios of cation to anion exchange resins in

  12. Ability of the TRAC-P1A computer program to predict blowdown, refill, and reflood phenomena during Semiscale Mod-1 experiments. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Demmie, P.N.

    1980-01-01

    A computer analysis of a Semiscale Mod-1 Loss-of-Coolant Experiment (LOCE) was performed using the TRAC-P1A computer program. The main purpose of this analysis was to contribute data for the assessment of the ability of TRAC-P1A to predict blowdown, refill, and reflood phenomena during a postulated Loss-of-Coolant Accident (LOCA). A TRAC-P1A Semiscale Mod-1 system model was created and TRAC-P1A was used to obtain initial conditions for Semiscale Mod-1 LOCE S-04-6. After this initialization, TRAC-P1A was used to simulate the first 60 seconds of this experiment. The results of this simulation are presented and discussed.

  13. System-level validation of CATHENA MOD-3.5D for early blowdown phase of large LOCA - RD-14M tests B0405-B0413

    Energy Technology Data Exchange (ETDEWEB)

    Gu, J.W.; McGee, G.R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)], E-mail: guj@aecl.ca

    2008-07-01

    To investigate the integrated effect of multiple phenomena on CATHENA MOD-3.5d code uncertainty, for the early blowdown phase of large loss of coolant accident (LOCA), one RD-14M test series (B0405-B0413) is used to perform a system-level validation. The peak sheath temperature in the Fuel-Element-Simulator (FES) is selected as the key output parameter used to quantify the code bias and uncertainty in the validation. In the nine tests, the test conditions (break size, pump and power trip time, fluid sub-cooling and pressurizer isolation) are systematically varied and simulated, so that their effects on the magnitude and timing of the peak FES-sheath temperatures are demonstrated. The base test, B0405 is selected to perform sensitivity and uncertainty analyses. The sensitivity analyses show that the choice of film-boiling heat-transfer correlation has a significant effect on the prediction of the FES-sheath temperatures during the FES quenching period. Uncertainty analysis demonstrates a mean bias of about +20{sup o}C, with a range of about {+-}30{sup o}C to the upper and lower bounds. These results compare very well with the estimated code accuracy based on all nine tests of B0405-B0413. (author)

  14. Heat transfer correlation development and assessment: a summary and assessment of return to nucleate boiling phenomena during blowdown tests conducted at the Idaho National Engineering Laboratory (INEL). [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, A. M.; Tolman, E. L.

    1979-04-01

    The data are presented which were obtained in Loss-of-Coolant Experiments (LOCE) at Idaho National Engineering Laboratory (INEL) which demonstrate the presence of cladding rewetting after the critical heat flux has been exceeded as a viable cooling mechanism during the blowdown phase of a LOCE. A brief review of the mechanisms associated with the boiling crisis and rewetting is also provided. The relevance of INEL LOCE rewetting data to nuclear reactor licensing Evaluation Model Requirements is considered, and the conclusion is made that the elimination of rewetting and return to nucleate boiling (RNB) in Evaluation Models represents a definite conservatism.

  15. 基于MATLAB软件的蒸汽锅炉连续排污余热回收设计%Process Design of Waste Heat Recovery in Continuous Blowdown of Steam Boiler Based on MATLAB Software

    Institute of Scientific and Technical Information of China (English)

    刘舒佳; 关文吉; 刘伟; 冯圣红; 孙晓禹

    2016-01-01

    An energy-saving scheme is proposed to solve the waste heat and water resources in continuous blowdown of steam boiler. Matlab software is utilized to design calculation program for heat exchanger in heat recovery of steam boiler's continuous blowdown because of the complex problems in heat recovery design. Iterative methods are applied to obtain the heat gain of the deaerated water tank and softened water tank respectively. The heat exchange area of heat exchanger is calculated and investigated in different ways in the process of the waste heat recovery. The optimal plan for calculating heat exchange area is selected with comparison and analysis. The energy saving effect of the continuous waste heat recovery scheme for steam boiler is analyzed and calculated.%为解决蒸汽锅炉连续排污余热回收过程中废热及水资源浪费的问题提出一种节能方案.针对蒸汽锅炉连续排污余热回收过程中换热器设计计算较为复杂的问题,运用Matlab软件就蒸汽锅炉连续排污余热回收过程中换热器的设计计算编写程序,使用迭代的方式得出除氧水箱与软化水箱的分别得热量,探讨以不同的方式计算余热回收过程中换热器换热面积的问题;对比分析换热面积计算的2种方法,选取较优方案.分析计算提出的蒸汽锅炉连续排污余热回收方案的节能效果.

  16. Power Generation Systems Using Continuous Blowdown Waste Heat From Drum Boilers Driving an Organic Rankine Cycle%利用汽包锅炉连续排污余热的有机朗肯循环发电系统

    Institute of Scientific and Technical Information of China (English)

    刘强; 段远源; 万绪财

    2013-01-01

    A power generation system which used the continuous blowdown waste heat to drive an organic Rankine cycle (ORC) was developed to improve the energy efficiency. The blowdown waste heat was recovered by organic fluid, and then generates power by expansion through a turbine. The analysis model of thermal performance for the system was established. The performance of seven ORC working fluids including R227ea, RC318, R236ea, R245fa, R245ca, R123 and R113 were optimized using the GRG algorithm, and the maximum power output was obtained. The results show that the optimum turbine inlet temperature increases as the critical temperature of the working fluid decreases for the o2 cycle which has saturated vapor entering the turbine. However, the superheating in the o3 cycle reduces the waste heat utilization ratio. Supercritical ORC improves the match of temperature profiles between the heat source and the working fluid, which helps to increase the system power output. But the high operation pressure and heat transfer deterioration due to the large specific heat near the critical point must be considered in the system design. The thermal performance and the power output of R236ea are better than the six other fluids.%提出了一种利用汽包锅炉排污系统余热的有机朗肯循环发电系统,有机工质回收扩容器疏水的热量,并通过气轮机发电。建立了系统的热力性能分析模型,并对 R227ea、RC318、R236ea、R245fa、R245ca、R123和R113等7种工质的热力性能进行了优化。结果表明,临界温度高的工质,其 o2循环的最佳主气温度(蒸发温度)反而低;亚临界循环采用干流体时,过热不利于余热的利用;超临界循环可以改善热源与工质间的温度匹配,有利于增大系统输出功,但是其运行压力高、大比热区的传热恶化等问题是实际运行和设计需要考虑的因素;R236ea的热力性能优于其余6种工质。

  17. Analysis on Fouling of Reverse Osmosis Systems in Reuse Process for Blowdown of Circulating Water%循环水排污水回用工艺中反渗透系统污堵原因分析

    Institute of Scientific and Technical Information of China (English)

    龙潇; 何彩燕; 石景燕; 侯文龙; 张宝山; 吴海峰

    2012-01-01

    The circulation water waste water reuse treatment process of a Hebei power plant was briefly introduced. A detailed test for the rapid rising pressure difference of security filter and the problem of reverse osmosis (RO) system fouling was made. The analysis results show that the local acid concentration of the reverse osmosis water plus acid point is too high. The high concentration result in the precipitation of the circulating water quality stabilizer, which plug in the security filter core surface. Thereby the micro-organisms breed, which lead to the rapid fouling in reverse osmosis system security filter. By adjusting the acid point, the phenomenon of the reverse osmosis fouling was eliminated and the system can operate normally.%简要介绍河北某电厂循环水排污水回用处理工艺.针对反渗透系统污堵及保安过滤器压差迅速上升问题进行了详细试验,逐一排查.分析结果表明,反渗透进水加酸点局部酸浓度过高,造成循环水中的水质稳定剂析出,堵在保安过滤器滤芯表面,进而引起微生物滋生,导致反渗透系统保安过滤器迅速污堵.经调整加酸点后再未出现反渗透污堵现象,系统运行正常.

  18. 76 FR 72311 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Final Exclusion

    Science.gov (United States)

    2011-11-23

    ... Scrubber water blowdown produced by the RKI's air pollution control equipment is also derived from the... Environmental Protection Agency (EPA) is granting a petition submitted by Eastman Chemical Corporation--Texas...) bottom ash, RKI fly ash, and RKI scrubber water blowdown. The RKI bottom ash and the RKI fly ash...

  19. Department of Energy's team's analyses of Soviet designed VVERs

    Energy Technology Data Exchange (ETDEWEB)

    1989-09-01

    This document provides Appendices A thru K of this report. The topics discussed respectively are: radiation induced embrittlement and annealing of reactor pressure vessel steels; loss of coolant accident blowdown analyses; LOCA blowdown response analyses; non-seismic structural response analyses; seismic analyses; S'' seal integrity; reactor transient analyses; fire protection; aircraft impacts; and boric acid induced corrosion. (FI).

  20. 循环水排污水中杀菌剂、缓蚀阻垢剂对混凝效果的影响%Effects of Bactericides,Corrosion and Scale Inhibitors on Coagulation in Blow-down Water From Circulating Water System

    Institute of Scientific and Technical Information of China (English)

    杨伟; 刘芳; 樊丰涛; 张利

    2015-01-01

    When the blow‐down water from circulating water system is treated by coagulant‐sedimentation method ,the water treatment agents in it would have a certain effect on coagulation effect .For seeking influence of the agents on the coagulation process and its mechanism , the dosages of coagulant ,coagulant aid and operating conditions were optimized firstly ,and then the effects of single and compound water treatment agents on coagulation were investigated . In addition ,the effects of agents on optimum dosing amount of coagulant were investigated and flocculation obtained under different conditions was analyzed by SEM .The results showed that the optimized dosages of PAC and PAM were 40 mg/L and 0.8 mg/L ,respectively ,and the optimal operating conditions were fast stirring for 3 min at 300 r/min and slow stirring for 10 min at 90 r/min ,under which the coagulation effect of blow‐down water was best and turbidity removal rate reached 93.49% .Polyaspartic acid (PASP) had a greatest influence on coagulation of blow‐down water and residual turbidity raged from 0.85 to 1.78 nephelometric turbidity unit (NTU ) , w hile dodecyl dimethyl benzyl ammonium chloride (1227) had a greatest influence on the optimum amount of PAC ,which ranged from 20 to 70 mg/L .Residual turbidity was greater than 0.98 NTU at the existence of compound agents . According to SEM photos , the difference in microstructures of flocculation from blow‐down water at different coagulation conditions led to different coagulation effect .%混凝沉淀法处理循环水排污水时,由于排污水中残余药剂的影响,混凝往往达不到理想效果。为了寻求药剂对混凝过程及机理的影响,首先对混凝剂(PAC)、助凝剂(PAM )的投加量以及混凝条件进行优化,然后在优化的混凝条件下,考察单体药剂以及复配药剂对排污水混凝效果的影响,还考察了药剂对 PAC最佳投加量的影响,并采用扫描电镜观测不同条件下絮凝体的微观结构。结果表明,PAC 和 PAM 的最佳投加量分别为40 mg/L、0.8 mg/L ,最佳混凝条件为快速搅拌时间3 min、慢速搅拌速率90 r/min、快速搅拌速率300 r/min、慢速搅拌时间10 min;在此条件下,排污水浊度去除率可达93.49%。PASP对排污水混凝效果影响最大,且剩余浊度波动性大,波动范围0.85~1.78 NTU (Nephelometric Turbidity Unit);1227对 PAC最佳投加量影响最大,波动范围20~70 mg/L。排污水存在复配药剂时,其混凝后得剩余浊度都大于无药剂时的0.98 N T U。不同条件下的排污水混凝所得絮凝体结构存在明显的差异,从而导致了混凝效果的不同。

  1. 直喷式直流电弧等离子化学气相沉积法金刚石单晶外延层制备研究%Growth of Diamond Single Crystal Epitaxial Layer by DC Arcjet Plasma Chemical Vapor Deposition at Blow-down Mode

    Institute of Scientific and Technical Information of China (English)

    刘杰; 黑立富; 陈广超; 李成明; 宋建华; 唐伟忠; 吕反修

    2014-01-01

    采用非循环直流喷射(直喷式)直流电弧等离子化学气相沉积法,在Ar/H2/CH4气氛下,成功制备了金刚石单晶外延层.试验采用的是3 mm×3 mm×1.2 mm的高温高压Ib型金刚石单晶衬底.研究了不同衬底温度和甲烷浓度对金刚石单晶外延层的形貌,速率和晶体质量的影响.采用光学显微镜,激光共聚焦表征了样品的形貌,利用千分尺测量其生长速率,利用Raman表征其晶体质量,采用OES诊断Ar/H2/CH4等离子气氛下C2、CH与Hβ的相对浓度.研究表明,温度和甲烷浓度对单晶刚石形貌和质量产生了明显的影响.在衬底为温度980℃,甲烷浓度在1.5%的条件下,生长速率达到了36 μm/h,并且晶体质量较好(半高宽仅为1.88 cm-1).同时发现生长参数对金刚石单晶外延层的生长模式有着显著地影响.

  2. 核电厂VVP101BA排放扩容器底部排污管线出口水温超标问题的处理%Treatment of VVP101BA Nuclear Power Plant Emissions Expanding Vessel Bottom Blowdown Pipeline Outlet Water Temperature Exceed the Standard Problem

    Institute of Scientific and Technical Information of China (English)

    张宪

    2015-01-01

    By raising the hydrophobic pipeline shaped water sealing bend door height and improve the cooling water water level discharge capacity expansion device, can guarantee the VVP101BA emission expanding vessel accumulate enough water, thereby cooling the hydrophobic effect. At the same time, modify the magnetic level gauge interface position, so as to solve the emissions expanding vessel magnetic type level gauge without reading problems.%通过抬高疏水管线门形水封弯管的高度和提高排放扩容器的冷却水水位高度,可保证VVP101BA排放扩容器积蓄足够的水量,从而达到冷却疏水的效果。同时,修改了磁力式翻板液位计接口的位置,从而解决了排放扩容器磁力式翻板液位计无读数的问题。

  3. Ammonia-water absorption refrigeration systems with flooded evaporators

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Sieres, Jaime [Area de Maquinas y Motores Termicos, Escuela Tecnica Superior de Ingenieros Industriales, Universidad de Vigo, Campus Lagoas-Marcosende No. 9, 36310 Vigo (Spain)

    2006-12-15

    The harmful effects of water accumulation in the evaporator in ammonia-water absorption refrigeration systems (AARS) with flooded evaporators are a crucial issue. In this paper, the effects of the ammonia purification and the liquid entrainment and blow-down from the evaporator in AARS are analyzed. A mathematical model based on a single stage system with complete condensation has been developed. The ammonia purification is evaluated by means of the Murphree efficiencies of the stripping and rectifying sections of the distillation column. The entrainment and blow-down are taking into account considering the corresponding flow rates as a fraction of the dry vapour at the evaporator outlet. The influence of the distillation column components efficiency on the attainable distillate concentration and the effects of the distillate concentration and the liquid entrainment and blow-down on the system operating conditions and performance are analyzed and quantified. If no liquid entrainment or blow-down is considered, very high efficiencies in the distillation column are required. Small values of liquid entrainment or blow-down fractions increase significantly the operating range of the absorption system. If high values of the blow-down fraction are required, then a heat exchanger should be added to the system in order to recover the refrigeration capacity of the blow-down by additional subcooling of the liquid from the condenser. For a fixed value of the distillation column efficiency, an optimum value of the liquid blow-down fraction exists. Moreover, an optimum combination of generation temperature, reflux ratio and blow-down fraction can be found, which should be considered in designing and controlling an AARS. (author)

  4. 75 FR 66757 - Stakeholder Input; Listening Session Seeking Suggestions for Improving the Next National...

    Science.gov (United States)

    2010-10-29

    ... runoff and above water line hull cleaning; bilge water; ballast water; anti-fouling leachate from anti-fouling hull coatings; aqueous film forming foam (AFFF); boiler/economizer blowdown; cathodic...

  5. Hypersonic Tunnel Facility (HTF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hypersonic Tunnel Facility (HTF) is a blow-down, non-vitiated (clean air) free-jet wind tunnel capable of testing large-scale, propulsion systems at Mach 5, 6,...

  6. LOFT reactor vessel 290/sup 0/ downcomer stalk instrument penetration flange stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Finicle, D.P.

    1978-06-06

    The LOFT Reactor Vessel 290/sup 0/ Downcomer Stalk Instrument Penetration Flange Stress Analysis has been completed using normal operational and blowdown loading. A linear elastic analysis was completed using simplified hand analysis techniques. The analysis was in accordance with the 1977 ASME Boiler and Pressure Vessel Code, Section III, for a Class 1 component. Loading included internal pressure, bolt preload, and thermal gradients due to normal operating and blowdown.

  7. Large-scale wind disturbances promote tree diversity in a Central Amazon forest.

    Science.gov (United States)

    Marra, Daniel Magnabosco; Chambers, Jeffrey Q; Higuchi, Niro; Trumbore, Susan E; Ribeiro, Gabriel H P M; Dos Santos, Joaquim; Negrón-Juárez, Robinson I; Reu, Björn; Wirth, Christian

    2014-01-01

    Canopy gaps created by wind-throw events, or blowdowns, create a complex mosaic of forest patches varying in disturbance intensity and recovery in the Central Amazon. Using field and remote sensing data, we investigated the short-term (four-year) effects of large (>2000 m(2)) blowdown gaps created during a single storm event in January 2005 near Manaus, Brazil, to study (i) how forest structure and composition vary with disturbance gradients and (ii) whether tree diversity is promoted by niche differentiation related to wind-throw events at the landscape scale. In the forest area affected by the blowdown, tree mortality ranged from 0 to 70%, and was highest on plateaus and slopes. Less impacted areas in the region affected by the blowdown had overlapping characteristics with a nearby unaffected forest in tree density (583 ± 46 trees ha(-1)) (mean ± 99% Confidence Interval) and basal area (26.7 ± 2.4 m(2) ha(-1)). Highly impacted areas had tree density and basal area as low as 120 trees ha(-1) and 14.9 m(2) ha(-1), respectively. In general, these structural measures correlated negatively with an index of tree mortality intensity derived from satellite imagery. Four years after the blowdown event, differences in size-distribution, fraction of resprouters, floristic composition and species diversity still correlated with disturbance measures such as tree mortality and gap size. Our results suggest that the gradients of wind disturbance intensity encompassed in large blowdown gaps (>2000 m(2)) promote tree diversity. Specialists for particular disturbance intensities existed along the entire gradient. The existence of species or genera taking an intermediate position between undisturbed and gap specialists led to a peak of rarefied richness and diversity at intermediate disturbance levels. A diverse set of species differing widely in requirements and recruitment strategies forms the initial post-disturbance cohort, thus lending a high resilience towards wind

  8. Ecological impact of chloro-organics produced by chlorination of cooling tower waters

    Energy Technology Data Exchange (ETDEWEB)

    Jolley, R L; Cumming, R B; Pitt, W W; Taylor, F G; Thompson, J E; Hartmann, S J

    1977-01-01

    Experimental results of the initial assessment of chlorine-containing compounds in the blowdown from cooling towers and the possible mutagenic activity of these compounds are reported. High-resolution liquid chromatographic separations were made on concentrates of the blowdown from the cooling tower at the High Flux Isotope Reactor (HFIR) and from the recirculating water system for the cooling towers at the Oak Ridge Gaseous Diffusion Plant (ORGDP), Oak Ridge, Tennessee. The chromatograms of chlorinated cooling waters contained numerous uv-absorbing and cerate-oxidizable constituents that are now being processed through a multicomponent identification procedure. Concentrates of the chlorinated waters are also being examined for mutagenic activity.

  9. Optimization of ion exchange in polishers at PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Miller, A.D. [Pedro Point Technology, Inc., Pacifica, CA (United States); Fruzzetti, K. [Electric Power Research Inst., Palo Alto, CA (United States)

    2004-08-01

    Blowdown polishers are indispensable components in the secondary systems of pressurized water reactors. The application of advanced amines to reduce iron levels in final steam generator feedwater influences the resin selection for and operation of condensate polishers. There are many opportunities to optimize blowdown polisher performance. This paper summarizes the work currently underway to optimally use resin properties such as ion selectivity and capacity and operational parameters to maximize water quality while minimizing cost. It is shown that the best amine for a given power plant is a complex function of amine properties, ion exchange resin choice, purification systems and other plant design and operational parameters. (orig.)

  10. Evaluation of the thermal-hydraulic response and fuel rod thermal and mechanical deformation behavior during the power burst facility test LOC-3. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Yackle, T.R.; MacDonald, P.E.; Broughton, J.M.

    1980-01-01

    An evaluation of the results from the LOC-3 nuclear blowdown test conducted in the Power Burst Facility is presented. The test objective was to examine fuel and cladding behavior during a postulated cold leg break accident in a pressurized water reactor (PWR). Separate effects of rod internal pressure and the degree of irradiation were investigated in the four-rod test. Extensive cladding deformation (ballooning) and failure occurred during blowdown. The deformation of the low and high pressure rods was similar; however, the previously irradiated test rod deformed to a greater extent than a similar fresh rod exposed to identical system conditions.

  11. LOCA air-injection loads in BWR Mark II pressure suppression containment systems

    Energy Technology Data Exchange (ETDEWEB)

    Kukita, Y.; Shiba, M. (Japan Atomic Energy Research Inst., Tokai, Ibaraki); Namatame, K. (Institute of Nuclear Safety, Tokyo (Japan))

    1984-02-01

    Large-scale blowdown tests were conducted to investigate the thermal-hydrodynamic response of a boiling-water reactor (BWR) Mark II pressure suppression containment system to a postulated loss-of-coolant accident. This paper presents the test results on the early blowdown transients, where air in the drywell is injected into the pressure suppression pool and induces various hydrodynamic loads onto the containment pressure boundary and internal structures. The test data are compared to predictions by analytical models used for the licensing evaluation of the hydrodynamic loads to assess these models.

  12. 40 CFR 125.93 - What special definitions apply to this subpart?

    Science.gov (United States)

    2010-07-01

    ... losses that have occurred due to blowdown, drift, and evaporation. Cooling water means water used for... significant inflows of water from oceans or bays due to tidal action. For the purposes of this rule, a flow... subpart? 125.93 Section 125.93 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  13. Application of UPTF data for modeling liquid draindown in the downcomer region of a PWR using RELAP5/MOD2-B&W

    Energy Technology Data Exchange (ETDEWEB)

    Wissinger, G.; Klingenfus, J. [B & W Nuclear Technologies, Lynchburg, VA (United States)

    1995-09-01

    B&W Nuclear Technologies (BWNT) currently uses an evaluation model that analyzes large break loss-of-coolant accidents in pressurized water reactors using several computer codes. These codes separately calculate the system performance during the blowdown, refill, and reflooding phases of the transient. Multiple codes are used, in part, because a single code has been unable to effectively model the transition from blowdown to reflood, particularly in the downcomer region where high steam velocities do not allow the injected emergency core cooling (ECC) liquid to penetrate and begin to refill the vessel lower plenum until after the end of blowdown. BWNT is developing a method using the RELAP5/MOD2-B&W computer code that can correctly predict the liquid draindown behavior in the downcomer during the late blowdown and refill phases. Benchmarks of this method have been performed against Upper Plenum Test Facility (UPTF) data for ECC liquid penetration and valves using both cold leg and downcomer ECC injection. The use of this new method in plant applications should result in the calculation of a shorter refill period, leading to lower peak clad temperature predictions and increased core peaking. This paper identifies changes made to the RELAP/MOD2-B&W code to improve its predictive capabilities with respect to the data obtained in the UPTF tests.

  14. Effects of multiple interacting disturbances and salvage logging on forest carbon stocks

    Science.gov (United States)

    Bradford, J.B.; Fraver, S.; Milo, A.M.; D'Amato, A.W.; Palik, B.; Shinneman, D.J.

    2012-01-01

    Climate change is anticipated to increase the frequency of disturbances, potentially impacting carbon stocks in terrestrial ecosystems. However, little is known about the implications of either multiple disturbances or post-disturbance forest management activities on ecosystem carbon stocks. This study quantified how forest carbon stocks responded to stand-replacing blowdown and wildfire, both individually and in combination with and without post-disturbance salvage operations, in a sub-boreal jack pine ecosystem. Individually, blowdown or fire caused similar decreases in live carbon and total ecosystem carbon. However, whereas blowdown increased carbon in down woody material and forest floor, fire increased carbon in standing snags, a difference that may have consequences for long-term carbon cycling patterns. Fire after the blowdown caused substantial additional reduction in ecosystem carbon stocks, suggesting that potential increases in multiple disturbance events may represent a challenge for sustaining ecosystem carbon stocks. Salvage logging, as examined here, decreased carbon stored in snags and down woody material but had no significant effect on total ecosystem carbon stocks.

  15. The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, U.S.A.

    Science.gov (United States)

    Fraver, Shawn; Jain, Theresa; Bradford, John B; D'Amato, Anthony W; Kastendick, Doug; Palik, Brian; Shinneman, Doug; Stanovick, John

    2011-09-01

    Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances-blowdown, salvage logging, and wildfire-provided an excellent opportunity to assess the impacts of blowdown and salvage logging on wildfire severity. We used two fire-severity assessments (tree-crown and forest-floor characteristics) to compare post-wildfire conditions among three treatment combinations (Blowdown-Salvage-Fire, Blowdown-Fire, and Fire only). Our results suggest that salvage logging reduced the intensity (heat released) of the subsequent fire. However, its effect on severity (impact to the system) differed between the tree crowns and forest floor: tree-crown indices suggest that salvage logging decreased fire severity (albeit with modest statistical support), while forest-floor indices suggest that salvage logging increased fire severity. We attribute the latter finding to the greater exposure of mineral soil caused by logging operations; once exposed, soils are more likely to register the damaging effects of fire, even if fire intensity is not extreme. These results highlight the important distinction between fire intensity and severity when formulating post-disturbance management prescriptions.

  16. The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, USA

    Science.gov (United States)

    Fraver, S.; Jain, T.; Bradford, J.B.; D'Amato, A.W.; Kastendick, D.; Palik, B.; Shinneman, D.; Stanovick, J.

    2011-01-01

    Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances-blowdown, salvage logging, and ildfire- provided an excellent opportunity to assess the impacts of blowdown and salvage logging on wildfire severity. We used two fire-severity assessments (tree-crown and forest-floor characteristics) to compare post-wildfire conditions among three treatment combinations (Blowdown-Salvage-Fire, Blowdown-Fire, and Fire only). Our results suggest that salvage logging reduced the intensity (heat released) of the subsequent fire. However, its effect on severity (impact to the system) differed between the tree crowns and forest floor: tree-crown indices suggest that salvage logging decreased fire severity (albeit with modest statistical support), while forest-floor indices suggest that salvage logging increased fire severity. We attribute the latter finding to the greater exposure of mineral soil caused by logging operations; once exposed, soils are more likely to register the damaging effects of fire, even if fire intensity is not extreme. These results highlight the important distinction between fire intensity and severity when formulating post-disturbance management prescriptions. ?? 2011 by the Ecological Society of America.

  17. 40 CFR 1700.5 - Discharges not requiring control.

    Science.gov (United States)

    2010-07-01

    ... Marine Pollution Control Device to mitigate adverse impacts on the marine environment: (a) Boiler Blowdown: the water and steam discharged when a steam boiler is blown down, or when a steam safety valve is..., which stores a steam/water mixture for launching aircraft from an aircraft carrier. (c)...

  18. JPRS Report, Science & Technology, Europe, ONERA: 1988 Report of French Aerospace Research Agency

    Science.gov (United States)

    2007-11-02

    blowdown wind tunnels, in particular for the Hermes program. As concerns the internal aerodynamics of turbomachines , initial results were achieved on a...results obtained on superalloys for turbomachine disks and blades and on their fabrication by powder metallurgy should be mentioned. For structures

  19. Summary of the Evergreen Operating Corporation Rosa No. 283 Well Cooperative Research Project San Juan Basin. Topical report, May 1, 1993-January 15, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Logan, T.L.; Robinson, J.R.

    1995-01-10

    The major objectives of the cooperative effort were to: recommend a remedial stimulation treatment to enhance gas production from a previously hydraulically fracture stimulated well; and Evaluate the effect of the remedial stimulation treatment using well testing techniques. The recommended remedial stimulation program consisted of a large volume nitrogen injection treatment followed by a controlled blow-down period, maintaining a high bottomhole flowing pressure. There were indications early in the producing life of the well that the near-wellbore permeability may be stress sensitive. Therefore, high producing back-pressures were maintained during the blow-down period in an attempt to limit cleat closure. However, analysis of post-remedial treatment production data indicates that higher gas rates are achieved at lower wellhead pressure rather than at higher wellhead back-pressure.

  20. Experimental investigation on unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine

    Institute of Scientific and Technical Information of China (English)

    ZHAO QingJun; LIU XiYang; WANG HuiShe; ZHAO XiaoLu; XU JianZhong

    2009-01-01

    An experimental investigation has been performed to study the unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine. The experiment is carried out on a blow-down short duration turbine facility. The investigation indicates that the blow-down short duration turbine facility is capable of substituting continuous turbine facilities in most turbine testing. Through this experimental investigation, a distinct blade-to-blade variation is observed. The results indicate that the combined effects of vane wake, tip leakage flow, complicated wave systems and rotor wake induce the remarkable blade-to-blade variations. The results also show that the unsteady effect is intensified along the flow direction.

  1. Experimental investigation on unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    An experimental investigation has been performed to study the unsteady pressure fluctuation of rotor tip region in high pressure stage of a vaneless counter-rotating turbine.The experiment is carried out on a blow-down short duration turbine facility.The investigation indicates that the blow-down short duration turbine facility is capable of substituting continuous turbine facilities in most turbine testing.Through this experimental investigation,a distinct blade-to-blade variation is observed.The results indicate that the combined effects of vane wake,tip leakage flow,complicated wave systems and rotor wake induce the remarkable blade-to-blade variations.The results also show that the unsteady effect is intensified along the flow direction.

  2. L2-3 pre-LOCE maneuver core safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, S.A.; Satterwhite, D.G.

    1979-04-19

    The core safety analyses and reactivity control analyses that have been done to support safe operation of the LOFT reactor in the LOCE pre-blowdown (or pre-LOCE) operating mode (Operating Mode 8) for the L2-3 nuclear loss of coolant experiment are presented. Safety analyses done to support LOFT operation in other operating modes (Modes 5, 6, and 7) with changes in operating conditions or assumptions due to requirements for safe operation of the L2-3 test (changes from conditions or assumptions for previous safety analyses for those operating modes) are also presented. The analyses discussed herein do not include analyses for potential loss of coolant accidents, or for accidents during the LOCE blowdown mode (Mode 9), or for potential radiation releases during LOCE operation.

  3. AGOR 28

    Science.gov (United States)

    2015-11-20

    currently balancing system. • Engine Room – FW Cooling system balancing is ongoing. • Electrical – DCI/Siemens is working on the DC ground fault issue(s...Ducts • 555-007-3 Blowdown & Operational Test of CO2 System – Hazmat Lockers and Tunnel Thruster Motor w/ USCG in attendance 7. Captain...Refrigeration Contractor aboard pressure testing piping between ships refer plants and compressors in BT space. Science Refer piping pressure

  4. Thermal and Mechanical Non-equilibrium Effects on Turbulent Flows Fundamental Studies of Energy Exchanges Through Direct Numerical Simulations and Experiments

    Science.gov (United States)

    2013-10-21

    with LIA. Diagnostics included hot - wire anemometry and laser Doppler velocimetry. Andreopoulos et al. (2000) presented concerns with this study: 1) the...that has passed through the generator. Measurement techniques generally utilize hot - wires and fast-response pressure probes. For blowdown wind tunnels...number ranged from 0.32 to 0.62, interacted with reflected shock waves of varying strengths. Hot - wires , pressure transducers, and Rayleigh scattering

  5. Mobile Information Collection Application: Water Equipment Tracker (MICA:WET) Tool

    Science.gov (United States)

    2013-10-01

    25 5.5 Steam boilers ...tower_makeup.htm ERDC TR-13-14 26 5.5 Steam boilers If the makeup water for the boiler plant is metered, then: Yearly Demand = annual total of makeup...usage. If the plant makeup water is not metered, it can be estimated from the amount of boiler blow-down plus the amount of steam used or lost in

  6. Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

    2009-06-30

    This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well as feasibility of managing cooling water quality with traditional chemical management schemes. Options for chemical treatment to prevent corrosion, scaling, and biofouling were identified through review of current practices, and were tested at bench and pilot-scale. Secondary treated wastewater is the most widely available impaired water that can serve as a reliable source of cooling water makeup. There are no federal regulations specifically related to impaired water reuse but a number of states have introduced regulations with primary focus on water aerosol 'drift' emitted from cooling towers, which has the potential to contain elevated concentrations of chemicals and microorganisms and may pose health risk to the public. It was determined that corrosion, scaling, and biofouling can be controlled adequately in cooling systems using secondary treated municipal wastewater at 4-6 cycles of concentration. The high concentration of dissolved solids in treated AMD rendered difficulties in scaling inhibition and requires more comprehensive pretreatment and scaling controls. Addition of appropriate chemicals can adequately control corrosion, scaling and biological growth in ash transport water, which typically has the best water quality among the three waters evaluated in this study. The high TDS in the blowdown from pilot-scale testing units with both passively treated mine drainage and secondary treated municipal wastewater and the high sulfate concentration in the mine drainage blowdown water were identified as the main challenges for blowdown

  7. PPOOLEX experiments on dynamic loading with pressure feedback

    Energy Technology Data Exchange (ETDEWEB)

    Puustinen, M.; Laine, J.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2011-01-15

    This report summarizes the results of the dynamic loading experiments (DYN series) carried out with the scaled down, two compartment PPOOLEX test facility designed and constructed at LUT. Steam was blown into the dry well compartment and from there through the DN200 vertical blowdown pipe to the condensation pool filled with sub-cooled water. The main purpose of the experiments was to study dynamic loads caused by different condensation modes. Particularly, the effect of counterpressure on loads due to pressure oscillations induced by chugging was of interest. Before the experiments the condensation pool was filled with isothermal water so that the blowdown pipe outlet was submerged by 1.03-1.11 m. The initial temperature of the pool water varied from 11 deg. C to 63 deg. C, the steam flow rate from 290 g/s to 1220 g/s and the temperature of incoming steam from 132 deg. C to 182 deg. C. Non-condensables were pushed from the dry well into the gas space of the wet well with a short discharge of steam before the recorded period of the experiments. As a result of this procedure, the system pressure was at an elevated level in the beginning of the actual experiments. An increased counterpressure was used in the last experiment of the series. The diminishing effect of increased system pressure on chugging intensity and on measured loads is evident from the results of the last experiment. The highest pressure pulses both inside the blowdown pipe and in the condensation pool were about half of those measured with a lower system pressure but otherwise with similar test parameters. The experiments on dynamic loading gave expected results. The loads experienced by pool structures depended strongly on the steam mass flow rate, pool water temperature and system pressure. The DYN experiments indicated that chugging and condensation within the blowdown pipe cause significant dynamic loads in case of strongly sub-cooled pool water. The level of pool water temperature is decisive

  8. Investigation of Natural Circulation Instability and Transients in Passively Safe Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Mamoru [Purdue Univ., West Lafayette, IN (United State

    2016-11-30

    between unstable and stable flow conditions in the dimensionless stability plane of inlet subcooling number and Zuber number. To predict the stability boundary theoretically, linear stability analysis in the frequency domain was performed at four sections of the natural circulation test loop. The flashing phenomena in the chimney section was considered as an axially uniform heat source. And the dimensionless characteristic equation of the pressure drop perturbation was obtained by considering the void fraction effect and outlet flow resistance in the core section. The theoretical flashing boundary showed some discrepancies with previous experimental data from the quasi-steady state tests. In the future, thermal non-equilibrium was recommended to improve the accuracy of flashing instability boundary. As another part of the funded research, flow instabilities of a PWR-type SMR under low pressure and low power conditions were investigated experimentally as well. The NuScale reactor design was selected as the prototype for the PWR-type SMR. In order to experimentally study the natural circulation behavior of NuScale iii reactor during accidental scenarios, detailed scaling analyses are necessary to ensure that the scaled phenomena could be obtained in a laboratory test facility. The three-level scaling method is used as well to obtain the scaling ratios derived from various non-dimensional numbers. The design of the ideally scaled facility (ISF) was initially accomplished based on these scaling ratios. Then the engineering scaled facility (ESF) was designed and constructed based on the ISF by considering engineering limitations including laboratory space, pipe size, and pipe connections etc. PWR-type SMR experiments were performed in this well-scaled test facility to investigate the potential thermal hydraulic flow instability during the blowdown events, which might occur during the loss of coolant accident (LOCA) and loss of heat sink accident (LOHS) of the prototype PWR

  9. Thermal hydraulic characteristics during ingress of coolant and loss of vacuum events in fusion reactors

    Science.gov (United States)

    Takase, K.; Kunugi, T.; Seki, Y.; Akimoto, H.

    2000-03-01

    The thermal hydraulic characteristics in the vacuum vessel (VV) of a fusion reactor under an ingress of coolant event (ICE) and a loss of vacuum event (LOVA) were investigated quantitatively using preliminary experimental apparatuses. In the ICE experiments, pressure rise characteristics in the VV were clarified for experimental parameters of the wall temperature and water temperature and for cases with and without a blowdown tank. In addition, the functional performance of a blowdown tank with and without a water cooling system was examined and it was confirmed that the blowdown tank with a water cooling system is effective for suppressing the pressure rise during the ICE. In the LOVA experiments, the saturation time in the VV from vacuum to atmosphere was investigated for various breach sizes and it was found that the saturation time is in inverse proportion to the breach size. In addition, the characteristics of exchange flow through breaches were clarified for the different breach positions on the VV. It was proven from the experimental results that the exchange flow became a counter-current flow when the breach was positioned on the top of the VV and a stratified flow when it was formed on the side wall of the VV, and that the exchange flow under the stratified flow condition was smoother than that of counter-current flow. On the basis of these results, the severest breach condition in ITER was changed from the top-break case to the side-break case. To predict with high accuracy the thermal hydraulic characteristics during ICEs and LOVAs under ITER conditions, a large scale test facility will be necessary. The current conceptual design of the combined ICE-LOVA test facility with a scaling factor of 1/1000 in comparison with the ITER volume is presented.

  10. Microlocal aspects of bistatic synthetic aperture radar imaging

    CERN Document Server

    Krishnan, Venky P

    2010-01-01

    In this article, we analyze the microlocal properties of the linearized forward scattering operator $F$ and the reconstruction operator $F^{*}F$ appearing in bistatic synthetic aperture radar imaging. In our model, the radar source and detector travel along a line a fixed distance apart. We show that $F$ is a Fourier integral operator, and we give the mapping properties of the projections from the canonical relation of $F$, showing that the right projection is a blow-down and the left projection is a fold. We then show that $F^{*}F$ is a singular FIO belonging to the class $I^{3,0}$.

  11. RTO Meeting Proceedings 16, Aircraft Weapon System Compatibility and Integration held in Chester, United Kingdom, 28-30 September, 1998

    Science.gov (United States)

    1999-04-01

    Thermovision 900 and then transferred via Ethernet blowdown. There is about a half a degree sting to a PC for analysis using MATLAB . A detailed deflection due...ACTUEL ddroulant entre la dds6lection de cette DEVANT EVOLUER fonction et la sortie du train Apr~s avoir illustr6 au travers de 1’exemple des b. Mise...cot d’aremen A inagrie onsi~r&armernent 21-5 0 Un mauvaise ad~quation du comportement de 1. un management des fonctions comimunes 1’arme lors de la

  12. The multi-dimensional module of CATHARE 2 description and application

    Energy Technology Data Exchange (ETDEWEB)

    Barre, F.; Dor, I.; Sun, C. [French Atomic Energy Commission (C.E.A.), Grenoble (France)

    1995-09-01

    In this paper, the three-dimensional module of CATHARE 2 is presented. It is based on a two-phase-flow six-equation model. A predictor/corrector multistep method, with an implicit behavior, is used to discretize the equations. Blowdown and boil-of analytical tests are used for an initial validation of the module. UPTF downcomer refill tests simulating the refill phase of a large-break loss-of-coolant accident are calculated. Additional models, including molecular and turbulent diffusion, are added in order to perform containment calculations.

  13. Steam line rupture experiments with the PPOOLEX test facility

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2008-07-15

    The results of the steam line rupture experiment series in 2007 with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology are reported. The test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. Air was blown into the dry well compartment and from there through a DN200 blowdown pipe to the condensation pool. Altogether five experiments, each consisting of several blows (tests), were carried out. The main purpose of the experiment series was to study the initial phase of a postulated steam line break accident inside a BWR containment. Specifically, thermal stratification in the dry well compartment and ejection of water plug from the blowdown pipe were of interest. In addition, the effect of counterpressure on bubble dynamics was studied. A temperature difference of approximately 15 deg. C between the upper and lower part of the dry well was measured. In the wet well gas space, a temperature difference of more than 30 deg. C was registered. These were measured during the compression period of the tests. Towards the end of the tests the temperature differences tended to disappear. To get a more detailed picture of temperature distribution in the wet well, especially close to the water level, a dense net of measurements is required in future experiments. In longer experiments, heat conduction to structures and heat losses to surroundings should also be taken into account. Ejection of water plugs from the blowdown pipe did not cause notable loads to the structures due to the suppressing effect of the dry well compartment. The maximum measured pressure pulse at the pool bottom was only 10 kPa and the maximum strain amplitude at the pool bottom rounding was negligible both in axial and circumferential direction. As the counterpressure of the system increased, but the flow rate remained the same, the maximum size of the air bubbles at the blowdown pipe outlet got smaller and

  14. AGOR 28: SIO Shipyard Representative Bi-Weekly Progress Report

    Science.gov (United States)

    2015-01-29

    switchboard is not rate for a space protected by water mist. The yard suggested that a fixed CO2 system would be better suited for this space due to the...require due to generator rating and the volume of the space. 5. Sally Ride Progress: • Sally Ride Electrical – The 690-volt switchboard is...24 VDC Chargers, Batteries & Alarms)(R/ASR) 84/0 AGOR27 A031- 04 STD Report - TEST REPORT ( 551-002-3 Start Air Compressors Operation, Blowdown

  15. Effects of non-uniform core flow on peak cladding temperature: MOXY/SCORE sensitivity calculations

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.C.

    1979-08-15

    The MOXY/SCORE computer program is used to evaluate the potential effect on peak cladding temperature of selective cooling that may result from a nonuniform mass flux at the core boundaries during the blowdown phase of the LOFT L2-4 test. The results of this study indicate that the effect of the flow nonuniformity at the core boundaries will be neutralized by a strong radial flow redistribution in the neighborhood of core boundaries. The implication is that the flow nonuniformity at the core boundaries has no significant effect on the thermal-hydraulic behavior and cladding temperature at the hot plane.

  16. Numerical Simulation of Pulse Detonation Rocket-Induced MHD Ejector (PDRIME) Concepts for Advanced Propulsion Systems

    Science.gov (United States)

    2012-02-28

    Engineering, 2010. 8 Roth, T., “ Modeling and Numerical Simulations of Pulse Detonation Engines with MHD Thrust Augmentation”, M.S. thesis, Department of...throat, at time 2.3ms. Results are shown for the PDE (blow-down model ) with and without MHD generation in the region between 0.4 and 0.8m from the...down model ) for different values of the exit- to-throat area ratio and for different altitudes, without MHD generation and without the presence of the

  17. The transpired turbulent boundary layer in various pressure gradients and the blow-off condition

    Science.gov (United States)

    Georgiou, D. P.; Louis, J. F.

    1984-12-01

    Experimental data are reported from studies of the cooling effectiveness and conditions leading to blow-off in transpiration cooling (TC). The TC configuration used featured a sintered bronze plate in a hot blowdown wind tunnel. Cooled air was pumped through the plate and data were gathered with calorimeters downstream of a piece of sandpaper which tripped the boundary layer. Pressure taps were also used. Local pressure gradient effects were small, but local accelerations reduced the cooling effectiveness. The downstream Stanton numbers were sensitive to the upstream coolant-injection ratio. Increasing the injection rate had, at best, only a small effect on the local heat flux.

  18. Blow-up of generalized complex 4-manifolds

    CERN Document Server

    Cavalcanti, Gil R

    2009-01-01

    We introduce blow-up and blow-down operations for generalized complex 4-manifolds. Combining these with a surgery analogous to the logarithmic transform, we then construct generalized complex structures on nCP2 # m \\bar{CP2} for n odd, a family of 4-manifolds which admit neither complex nor symplectic structures unless n=1. We also extend the notion of a symplectic elliptic Lefschetz fibration, so that it expresses a generalized complex 4-manifold as a fibration over a two-dimensional manifold with boundary.

  19. ORNL rod-bundle heat-transfer test data. Volume 6. Thermal-hydraulic test facility experimental data report for test 3. 05. 5B - double-ended cold-leg break simulation

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-05-18

    Thermal-Hydraulic Test Facility (THTF) Test 3.05.5B was conducted by members of the ORNL PWR Blowdown Heat Transfer Separate-Effects Program on July 3, 1980. The objective of the program is to investigate heat transfer phenomena believed to occur in PWRs during accidents, including small and large break loss-of-coolant accidents. Test 3.05.5B was designed to provide transient thermal-hydraulics data in rod bundle geometry under reactor accident-type conditions. Reduced instrument responses are presented. Also included are uncertainties in the instrument responses, calculated mass flows, and calculated rod powers.

  20. Hazardous Waste Minimization Assessment: Fort Sam Houston, Texas

    Science.gov (United States)

    1991-01-01

    Management Office. The contributions made by Ms. Sharon McClellan (FORSCOM); and Mr. Chittaranjan Ray, Mr. Richard Stanbaugh, Mr. Douglas Knowlton, and Ms...Blakesless, Inc. NRS-60 45-60 gal/h 2001 N. Janice Avenue HRS-60 45-60 gal/h Melrose Park. IL 60160 (solvents: TCE, 1.1.1-TCE, PCE) Branson Cleaning Equip...test feedwater. In addition, boiler blowdown liquid mixed with water is a hazardous waste generated periodically. Waste oil blended with virgin fuel

  1. Hazardous Waste Minimization Assessment: Fort Carson, CO

    Science.gov (United States)

    1991-01-01

    Management Office. The contributions made by Ms. Sharon McClellan (FORSCOM); and Mr. Chittaranjan Ray and Mr. Richard Stanbaugh (both of USACERL), in...IL 60160 (solvents: TCE, 1,1,1-TCE. PCE) Branson Cleaning Equipment S111W 9-15 gal/h -- Co. S121W 21-31 gal/h -- Parrot Drive, P.O. Box 768 Shelton...In addition, boiler blowdown liquid mixed with water is a hazardous waste generated periodically. Waste oil blended with virgin fuel oil is burned in

  2. Hazardous Waste Minimization Assessment: Fort Ord, CA

    Science.gov (United States)

    1991-06-01

    Gloria J. Wienke, USACERL Information Management Office. The contributions made by Ms. Sharon McClellan (FORSCOM); and Mr. Chittaranjan Ray, Mr. Richard ...gal/h ... Melrose Park, IL 60160 (solvents: TCE, 1,1,1-TCE, PCE) Branson Cleaning Equipment SilW 9-15 gal/h -- Co. S121W 21-31 gal/h -- Parrot Drive...boiler blowdown liquid mixed with water is a hazardous waste generated periodically. Waste oil blended with virgin fuel oil is burned in boilers at some

  3. Evaluation of the RELAP4/MOD6 thermal-hydraulic code. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Haigh, W.S.; Margolis, S.G.; Rice, R.E.

    1978-01-01

    The NRC RELAP4/MOD6 computer code was recently released to the public for use in thermal-hydraulic analysis. This code has a unique new capability permitting analysis of both the blowdown and reflood portions of a postulated pressurized water reactor (PWR) loss-of-coolant accident (LOCA). A principal code evaluation objective is to assess the accuracy of the code for computing LOCA behavior over a wide range of system sizes and scaling concepts. The scales of interest include all LOCA experiments and will ultimately encompass full-sized PWR systems for which no experiments or data are available. Quantitative assessment of the accuracy of the code when it is applied to large PWR systems is still in the future. With RELAP4/MOD6, however, a technique has been demonstrated for using results derived from small-scale blowdown and reflood experiments to predict the accuracy of calculations for similar experiments of significantly different scale or component size. This demonstration is considered a first step in establishing confidence levels for the accuracy of calculations of a postulated LOCA.

  4. The Effect of Temperature of Opening and Closed Cooling Water on Selecting Plate Heat Exchangers%汽轮机低压缸排污系统设计

    Institute of Scientific and Technical Information of China (English)

    郭锋; 刘杨

    2012-01-01

    汽轮机在低压缸靠近轴承两端设置有排污口,此接口主要用于排放低压缸凝结水,由于靠近汽轮机轴承,因此这部分凝结水含有油,但由于排放量小,绝大部分工程将此路排污水直接排至凝汽器,含油废水排放至凝汽器会污染凝结水,结合低压缸排污参数特点设计一种水封排污罐,这种设计简单,便于布置,以供同行参考借鉴.%There are blowdown interfaces at bearing side of LP. They are using for condensate of the LP. Because of they are near the bearing,so oil maybe contain in the condensate. Because the quantity of condensate is little,so it is discharged to the condenser nearly all projects. It will affect condensate quality. In this paper,there is a new kind of water-sealing blowdown tank designed,it is easily designed and fixed.

  5. Assessment of TRACE Code for GE Level Swell Test to Review Industrial Code

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chanyi; Cheng, Ae Ju; Bang, Young Seok; Hwang, Taesuk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    Korea Institute of Nuclear Safety(KINS) has reviewed the industrial code for safety analysis of nuclear power plant, in which TRACE and MARS-KS codes are being used to support the understanding of specific phenomena and code prediction. For this aspect, the TRACE code was assessed for the GE Level Swell Experiment. General Electric (GE) performed a series of experiments to investigate thermal-hydraulic phenomena such as critical flow, void distribution, and liquid-vapor mixture swell during blowdown conditions. These GE Level swell experiments are frequently simulated to verify safety analysis codes as a separate effect test. TRACE code calculations with version 5.0 patch 4 for GE Level Swell experiment 1004-3 have been performed to assess the applicability of the TRACE code for verification of industrial code. An Assessment analysis of the TRACE version 5.0 patch 4 code was carried out for GE Level Swell experiments 1004-3 by comparison purpose with SPACE. Overall, TRACE predicted the pressure and axial void fractions at different times reasonably well for 1004-3 blowdown test, while SPACE tends to underestimate the pressure. It was also found that results of void fraction distribution should be compared at different time to discuss the accuracy of the SPACE code against this test.

  6. Preliminary Sensitivity Study of Upper Head Nodalization for LBLOCA in APR-1400

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Gu; Yoo, Seung Hun; Cho, Dae-Hyung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    In this study, the key-way bypass was determined to be - 0.3 %. The steady state condition which is the initial condition for LBLOCA was obtained by MARS-KS calculation. Up to now, it was assumed that the temperature of the upper dome in APR-1400 was close to that of the cold leg. However, it was found that the temperature of the upper head/dome might be a little lower than or similar to that of the hot leg through the evaluation of the detailed design data. Since the higher upper head temperature affects blowdown quenching and peak cladding temperature in the reflood phase, the nodalization for upper head should be modified. In this study, the preliminary sensitivity study of original and modified nodalization for LBLOCA was performed, and the effect of upper head nodalization and temperature was evaluated qualitatively. In this study, the preliminary sensitivity study of original and modified nodalization for upper head in APR-1400 was performed, and the effect of upper head nodalization and temperature on LBLOCA PCT was evaluated qualitatively. Through the transient calculation, it was confirmed that the upper head temperature affects the water inventory in the upper head at the early stage of LBLOCA so it does the blowdown quenching and following reflood PCT significantly. The results in this study were caused by very conservative upper head temperature determination.

  7. Reactor safety issues resolved by the 2D/3D program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The 2D/3D Program studied multidimensional thermal-hydraulics in a PWR core and primary system during the end-of-blowdown and post-blowdown phases of a large-break LOCA (LBLOCA), and during selected small-break LOCA (SBLOCA) transients. The program included tests at the Cylindrical Core Test Facility (CCTF), the Slab Core Test Facility (SCTF), and the Upper Plenum Test Facility (UPTF), and computer analyses using TRAC. Tests at CCTF investigated core thermal-hydraulics and overall system behavior while tests at SCTF concentrated on multidimensional core thermal-hydraulics. The UPTF tests investigated two-phase flow behavior in the downcomer, upper plenum, tie plate region, and primary loops. TRAC analyses evaluated thermal-hydraulic behavior throughout the primary system in tests as well as in PWRs. This report summarizes the test and analysis results in each of the main areas where improved information was obtained in the 2D/3D Program. The discussion is organized in terms of the reactor safety issues investigated. This report was prepared in a coordination among US, Germany and Japan. US and Germany have published the report as NUREG/IA-0127 and GRS-101 respectively. (author).

  8. Prediction of a propellant tank pressure history using state space methods

    Science.gov (United States)

    Estey, P. N.; Lewis, D. H., Jr.; Connor, M.

    1983-01-01

    An analysis of the time response of a propellant supply system operating in the blowdown mode is presented. The supply system is part of a pump-fed propulsion system intended for use on interplanetary spacecraft. As such, the supply system must provide the pump with propellant at sufficient pressure to avoid pump cavitation. The system, consisting of the tank, the liquid propellant, the pressurant gas and propellant vapor mixture, and a film layer separating the liquid and vapor phases, is analyzed using the principles of mass and energy conservation. The resulting set of ordinary, coupled, nonlinear differential equations for the thermodynamic state variables is integrated as an initial value problem. The resulting histories of total pressure, propellant vapor pressure, propellant liquid temperature, film layer temperature, propellant vapor/pressurant gas temperature, propellant vapor mass, and propellant liquid mass enable the calculation of the net positive suction head available at the pump which determines the viability of the pump-fed system concept when operated in the blowdown mode.

  9. Dispersant trial at ANO-2: Results from a short-term trial prior to SG replacement

    Energy Technology Data Exchange (ETDEWEB)

    Fruzzetti, K.; Frattini, P. [Electric Power Research Inst., Palo Alto, CA (United States); Robbins, P. [Entergy Operations, Arkansas Nuclear One, Russellville, AR (United States); Miller, A. [Pedro Point Technology, Inc., Pacifica, CA (United States); Varrin, R.; Kreider, M. [Dominion Engineering Inc., McLean, VA (United States)

    2002-07-01

    Corrosion products in the secondary side of pressurized water reactor (PWR) steam generators (SGs) primarily deposit on the SG tubes. These deposits can inhibit heat transfer, lead to thermal-hydraulic instabilities through blockage of tube supports, and create occluded regions where corrosive species can concentrate along tubes and in tube-to-tube support plate crevices. The performance of the SGs is compromised not only by formation of an insulating scale, but by the removal of tubes from service due to corrosion. A potential strategy for minimizing deposition of corrosion products on SG internal surfaces is to use an online dispersant to help prevent the corrosion products from adhering to the steam generator surfaces. By inhibiting the deposition of the corrosion products, the dispersant can facilitate more effective removal from the SGs via blowdown. This type of strategy has been employed at fossil boilers for many decades. However, due to the use of inorganic (sulfur and other impurities) polymerization initiators, polymeric dispersants had not been utilized in the nuclear industry. Only recently has a poly-acrylic acid dispersant, developed by BetzDearborn (PAA), been available that meets the criteria for nuclear application. This paper summarizes the results of the short-term PAA dispersant trial in Winter/Spring 2000, lasting approximately 3 months, performed at Arkansas nuclear one unit 2 (ANO-2)-including the chronology of the trial, the increase in blowdown iron removal efficiency with use of the dispersant, and observed effects on SG performance. (authors)

  10. Validation of Effective Models for Simulation of Thermal Stratification and Mixing Induced by Steam Injection into a Large Pool of Water

    Directory of Open Access Journals (Sweden)

    Hua Li

    2014-01-01

    Full Text Available The Effective Heat Source (EHS and Effective Momentum Source (EMS models have been proposed to predict the development of thermal stratification and mixing during a steam injection into a large pool of water. These effective models are implemented in GOTHIC software and validated against the POOLEX STB-20 and STB-21 tests and the PPOOLEX MIX-01 test. First, the EHS model is validated against STB-20 test which shows the development of thermal stratification. Different numerical schemes and grid resolutions have been tested. A 48×114 grid with second order scheme is sufficient to capture the vertical temperature distribution in the pool. Next, the EHS and EMS models are validated against STB-21 test. Effective momentum is estimated based on the water level oscillations in the blowdown pipe. An effective momentum selected within the experimental measurement uncertainty can reproduce the mixing details. Finally, the EHS-EMS models are validated against MIX-01 test which has improved space and time resolution of temperature measurements inside the blowdown pipe. Excellent agreement in averaged pool temperature and water level in the pool between the experiment and simulation has been achieved. The development of thermal stratification in the pool is also well captured in the simulation as well as the thermal behavior of the pool during the mixing phase.

  11. Quarterly technical progress report on water reactor safety programs sponsored by the Nuclear Regulatory Commission's Division of Reactor Safety Research, January--March 1976

    Energy Technology Data Exchange (ETDEWEB)

    Zane, J. O.; Farman, R. F.; Hanson, D. J.; Peterson, A. C.; Ybarrondo, L. J.; Berta, V. T.; Naff, S. A.; Crocker, J. G.; Martinson, Z. R.; Smolik, G. R.; Cawood, G. W.; Quapp, W. J.; Ramsthaler, J. H.; Ransom, V. H.; Scofield, M. P.; Dearien, J. A.; Bohn, M. P.; Burnham, B. W.; James, S. W.; Lee, W. H.; Lime, J. F.; Nalezny, C. L.; MacDonald, P. E.; Thompson, L. B.; Domenico, W. F.; Rice, R. E.; Hendrix, C. E.; Davis, C. B.

    1976-06-01

    Light water reactor sfaety research performed January through March 1976 is summarized. Results of the Semiscale Mod-1 blowdown heat transfer test series relating to those phenomena that influence core fluid and heat transfer effects are analyzed, and preliminary analyses of the recently completed reflood heat transfer test series are summarized for the forced and gravity feed reflood tests. The first nonnuclear LOCE in the LOFT program was successfully completed and preliminary results are presented. Preliminary results are given for the PCM 8-1 RF Test, the PCM-2A Test, and the Irradiation Effects Scoping Test 2 in the Thermal Fuel Behavior Program. Model development and verification efforts reported in the Reactor Behavior Program include checkout of RELAP4/MOD5 Update 1, development of a new hydrodynamic model for two-phase separated flows, development of the RACHET code to assess the assumptions in current fuel behavior codes of uniform stress and strain in the cladding, modifications of the containment code BEACON, analysis of results from the Halden Assembly IFA-429 helium sorption experiment, development of correlations for the thermal conductivity of UO/sub 2/ and (U,Pu)O/sub 2/, and evaluation of RALAP4 through comparison of calculated results with data from the GE Blowdown Heat Transfer and Semiscale experiments.

  12. Relations between must clarification and organoleptic attributes of wine varietes

    Directory of Open Access Journals (Sweden)

    Vladimír Vietoris

    2014-02-01

    Full Text Available Blowdown musts is important operation performed in winemaking, which can have a major impact on the future quality of the wine. Blowdown of the wine removes components that may carry elements that negatively affect the hygienic and sensory quality of the wine. Fining of musts and wines is carried either by a static method or using different fining preparations. The aim of this work was to evaluate the effect of different methods of decanting on the wine quality varieties of Sauvignon. The overall sensory quality was evaluated (100 - points system, and semantic differential and the aromatic profile (profile method. All sensory evaluations were practiced by skilled sensory panel in controled conditions of Faculty sensory lab. Wine samples were clarified by static manner or with the assistance of the preparation applied to the clarification of wine in two different doses. By the results and their visualization of flavour and smell profile by spider plots we could conclude that pure cultures have positive effect on processed wine. Based on the results we found a beneficial effect of clearing by the clarification of the preparation based on cellulose, polyvinylpolypyrrolidone, gelatin and mineral adsorbents at 100 g.100 L-1  of the sensory quality of the wine.

  13. Development and validation of effective models for simulation of stratification and mixing phenomena in a pool of water

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Kudinov, P.; Villanueva, W. (Royal Institute of Technology (KTH). Div. of Nuclear Power Safety (Sweden))

    2011-06-15

    This work pertains to the research program on Containment Thermal-Hydraulics at KTH. The objective is to evaluate and improve performance of methods, which are used to analyze thermal-hydraulics of steam suppression pools in a BWR plant under different abnormal transient and accident conditions. The pressure suppression pool was designed to have the capability as a heat sink to cool and condense steam released from the core vessel and/or main steam line during loss of coolant accident (LOCA) or opening of safety relief valve in normal operation of BWRs. For the case of small flow rates of steam influx, thermal stratification could develop on the part above the blowdown pipe exit and significantly impede the pool's pressure suppression capacity. Once steam flow rate increases significantly, momentum introduced by the steam injection and/or periodic expansion and collapse of large steam bubbles due to direct contact condensation can destroy stratified layers and lead to mixing of the pool water. We use CFD-like model of the general purpose thermal-hydraulic code GOTHIC for addressing the issues of stratification and mixing in the pool. In the previous works we have demonstrated that accurate and computationally efficient prediction of the pool thermal-hydraulics in the scenarios with transition between thermal stratification and mixing, presents a computational challenge. The reason is that direct contact condensation phenomena, which drive oscillatory motion of the water in the blowdown pipes, are difficult to simulate with original GOTHIC models because of appearance of artificial oscillations due to numerical disturbances. To resolve this problem we propose to model the effect of steam injection on the mixing and stratification with the Effective Heat Source (EHS) model and the Effective Momentum Source (EMS) model. We use POOLEX/PPOOLEX experiment (Lappeenranta University of Technology in Finland), in order to (a) quantify errors due to GOTHIC

  14. Application of Pulse Spark Discharges for Scale Prevention and Continuous Filtration Methods in Coal-Fired Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young; Fridman, Alexander

    2012-06-30

    The overall objective of the present work was to develop a new scale-prevention technology by continuously precipitating and removing dissolved mineral ions (such as calcium and magnesium) in cooling water while the COC could be doubled from the present standard value of 3.5. The hypothesis of the present study was that if we could successfully precipitate and remove the excess calcium ions in cooling water, we could prevent condenser-tube fouling and at the same time double the COC. The approach in the study was to utilize pulse spark discharges directly in water to precipitate dissolved mineral ions in recirculating cooling water into relatively large suspended particles, which could be removed by a self-cleaning filter. The present study began with a basic scientific research to better understand the mechanism of pulse spark discharges in water and conducted a series of validation experiments using hard water in a laboratory cooling tower. Task 1 of the present work was to demonstrate if the spark discharge could precipitate the mineral ions in water. Task 2 was to demonstrate if the selfcleaning filter could continuously remove these precipitated calcium particles such that the blowdown could be eliminated or significantly reduced. Task 3 was to demonstrate if the scale could be prevented or minimized at condenser tubes with a COC of 8 or (almost) zero blowdown. In Task 1, we successfully completed the validation study that confirmed the precipitation of dissolved calcium ions in cooling water with the supporting data of calcium hardness over time as measured by a calcium ion probe. In Task 2, we confirmed through experimental tests that the self-cleaning filter could continuously remove precipitated calcium particles in a simulated laboratory cooling tower such that the blowdown could be eliminated or significantly reduced. In addition, chemical water analysis data were obtained which were used to confirm the COC calculation. In Task 3, we conducted a series

  15. Chemical mode in secondary circuit of the Dukovany NPP units after TG condensers replacement

    Energy Technology Data Exchange (ETDEWEB)

    Kopriva, M.; Shejbal, J.; Petrecky, I. [Dukovany NPP (Czech Republic)

    2002-07-01

    The increase of the pH of SG feedwater on the 1. unit of Dukovany NPP led to enhancement of chemical mode of secondary circuit, what was identified in particular by the following: Reduction of concentration of iron in SG feedwater, Reduction of concentration of Sodium and Sulfates in SG blowdown water. This reduction is caused by shutdown of CPS thus by elimination of release of Na ions and SO{sub 4} from wrong operated ion-exchangers and their subsequent regeneration (part of cation exchanger in Na form and part of anion exchanger in SO{sub 4} form). Reduction of the WANO SG chemical index to the minimum theoretical value. It will be necessary to change criteria characterizing this index or to introduce our own modified index. In relation to CPS shutdown the costs for operating chemicals and for demineralized flushing water were reduced. (authors)

  16. Adsorption process to recover hydrogen from feed gas mixtures having low hydrogen concentration

    Science.gov (United States)

    Golden, Timothy Christopher; Weist, Jr., Edward Landis; Hufton, Jeffrey Raymond; Novosat, Paul Anthony

    2010-04-13

    A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

  17. Study of using microfiltration and reverse osmosis membrane technologies for reclaiming cooling water in the power industry.

    Science.gov (United States)

    Li, J; Xu, Z Y; An, H G; Liu, L Q

    2007-07-01

    A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times.

  18. Technology evaluation report: SITE (Superfund Innovative Technology Evaluation) program demonstration test. The American Combustion Pyretron Thermal Destruction System at the US EPA's (Environmental Protection Agency's) combustion research facility

    Energy Technology Data Exchange (ETDEWEB)

    Waterland, L.; Lee, J.W.

    1989-04-01

    A series of demonstration tests of the American Combustion, Inc., Thermal Destruction System was performed under the SITE program. This oxygen-enhanced combustion system was retrofit to the rotary-kiln incinerator at EPA's Combustion Research Facility. The system's performance was tested firing contaminated soil from the Stringfellow Superfund Site, both alone and mixed with a coal tar waste (KO87). Comparative performance with conventional incinerator operation was also tested. Compliance with the incinerator performance standards of 99.99% principal organic hazardous constituents (POHC) destruction and removal efficiency and particulate emissions of less than 180 mg/dscm at 7% O2 was measured for all tests. The Pyretron system was capable of in-compliance performance at double the mixed waste feedrate and at a 60% increase in batch waste charge mass than possible with conventional incineration. Scrubber blowdown and kiln ash contained no detectable levels of any of the POHCs chosen.

  19. A fine-wire thermocouple probe for measurement of stagnation temperatures in real gas hypersonic flows of nitrogen

    Science.gov (United States)

    Hollis, Brian R.; Griffith, Wayland C.; Yanta, William J.

    1991-01-01

    A fine-wire thermocouple probe was used to determine freestream stagnation temperatures in hypersonic flows. Data were gathered in a N2 blowdown wind tunnel with runtimes of 1-5 s. Tests were made at supply pressures between 30 and 1400 atm and supply temperatures between 700 and 1900 K, with Mach numbers of 14 to 16. An iterative procedure requiring thermocouple data, pilot pressure measurements, and supply conditions was used to determine test cell stagnation temperatures. Probe conduction and radiation losses, as well as real gas behavior of N2, were accounted for during analysis. Temperature measurement error was found to be 5 to 10 percent. A correlation was drawn between thermocouple diameter Reynolds number and temperature recovery ratio. Transient probe behavior was studied and was found to be adequate in temperature gradients up to 1000 K/s.

  20. Connes-Chern character for manifolds with boundary and eta cochains

    CERN Document Server

    Lesch, Matthias; Pflaum, Markus J

    2009-01-01

    We represent the Connes-Chern character of the Dirac operator associated to a b-metric on a manifold with boundary in terms of a retracted cocycle in relative cyclic cohomology, whose expression depends on a scaling/cut-off parameter. Blowing-up the metric one recovers the pair of characteristic currents that represent the corresponding de Rham relative homology class, while the blow-down yields a cocycle whose expression involves higher eta cochains and their b-analogues. The corresponding formulae for the pairing with relative K-theory classes retain information about the boundary, and thus have geometric implications. In particular, they lead to a generalization of the Atiyah-Patodi-Singer odd-index theorem, from trivialized flat bundles to any pair of K-equivalent vector bundles.

  1. Liquid neon heat transfer as applied to a 30 tesla cryomagnet

    Science.gov (United States)

    Papell, S. S.; Hendricks, R. C.

    1975-01-01

    Since superconducting magnets cooled by liquid helium are limited to magnetic fields of about 18 teslas, the design of a 30 tesla cryomagnet necessitates forced convection liquid neon heat transfer in small coolant channels. As these channels are too small to handle the vapor flow if the coolant were to boil, the design philosophy calls for suppressing boiling by subjecting the fluid to high pressures. Forced convection heat transfer data are obtained by using a blowdown technique to force the fluid vertically through a resistance-heated instrumented tube. The data are obtained at inlet temperatures between 28 and 34 K and system pressures between 28 to 29 bars. Data correlation is limited to a very narrow range of test conditions, since the tests were designed to simulate the heat transfer characteristics in the coolant channels of the 30 tesla cryomagnet concerned. The results can therefore be applied directly to the design of the magnet system.-

  2. The impact of plasma induced flow on the boundary layer in a narrow channel

    Directory of Open Access Journals (Sweden)

    Procházka P.

    2015-01-01

    Full Text Available The induced flow generated by dielectric barrier discharge (DBD actuator working in steady and unsteady regime will be used to modify properties of naturally developed boundary layer (BL in short and long rectangular perspex channel which is connected to the blow-down wind tunnel. The actuator is placed in spanwise configuration and the inlet velocities will range between 5 and 20 m•s-1. Previously, mean flow field and statistical quantities were subjugated to investigation. In this paper, there will be presented dynamical features of the BL. Oscillation pattern decomposition (OPD of influenced flow field and frequency analysis will be presented. These results should be taken into account regarding to use in the flow around a bluff body.

  3. Investigation of some green compounds as corrosion and scale inhibitors for cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. (Aligarh Muslim Univ. (India))

    1999-05-01

    The performance of an open-recirculating cooling system, an important component in most industries, is affected by corrosion and scale formation. Numerous additives have been used in the past for the control of corrosion and scale formation. Effects of the naturally occurring compounds azadirachta indica (leaves), punica granatum (shell), and momordica charantia (fruits), on corrosion of mild steel in 3% sodium chloride (NaCl) were assessed using weight loss, electrochemical polarization, and impedance techniques. Extracts of the compounds exhibited excellent inhibition efficiencies comparable to that of hydroxyethylidine diphosphonic acid (HEDP), the most preferred cooling water inhibitor. The compounds were found effective under static and flowing conditions. Extracts were quite effective in retarding formation of scales, and the maximum antiscaling efficiency was exhibited by the extract of azadirachta indica (98%). The blowdown of the cooling system possessed color and chemical oxygen demand (COD). Concentrations of these parameters were reduced by an adsorption process using activated carbon as an adsorbent.

  4. INCAS TRISONIC WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Florin MUNTEANU

    2009-09-01

    Full Text Available The 1.2 m x 1.2 m Trisonic Blowdown Wind Tunnel is the largest of the experimental facilities at the National Institute for Aerospace Research - I.N.C.A.S. "Elie Carafoli", Bucharest, Romania. The tunnel has been designed by the Canadian company DSMA (now AIOLOS and since its commissioning in 1978 has performed high speed aerodynamic tests for more than 120 projects of aircraft, missiles and other objects among which the twin jet fighter IAR-93, the jet trainer IAR-99, the MIG-21 Lancer, the Polish jet fighter YRYDA and others. In the last years the wind tunnel has been used mostly for experimental research in European projects such as UFAST. The high flow quality parameters and the wide range of testing capabilities ensure the competitivity of the tunnel at an international level.

  5. Environmental assessment of the projected uses for geopressured waters

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.S.; Manning, J.A.; Meriwether, J.

    1977-11-16

    An assessment of possible environmental effects of the use of geopressured water of the Texas and Louisiana Gulf Coast has been made. The uses considered include generation of electric power, production of low pressure steam for process heat and the direct use of the hot water for space heating. Based upon the projected uses, the direct and indirect emissions are estimated and the impact of these emissions upon the environment are discussed. The possible impacts of the production of large volumes of geopressured fluids are also considered in terms of possibility of subsidence and earthquakes. A summary of available analyses of Gulf Coast deep waters is listed as a guide for estimating expected emissions. Primary environmental problems are identified as waste brine disposal, accidental releases of brines, and subsidence. Minor problems such as cooling tower blowdown streams, noncondensable gas emissions, wind drift from exhaust plumes, noise levels, and construction activities are considered.

  6. PDE Nozzle Optimization Using a Genetic Algorithm

    Science.gov (United States)

    Billings, Dana; Turner, James E. (Technical Monitor)

    2000-01-01

    Genetic algorithms, which simulate evolution in natural systems, have been used to find solutions to optimization problems that seem intractable to standard approaches. In this study, the feasibility of using a GA to find an optimum, fixed profile nozzle for a pulse detonation engine (PDE) is demonstrated. The objective was to maximize impulse during the detonation wave passage and blow-down phases of operation. Impulse of each profile variant was obtained by using the CFD code Mozart/2.0 to simulate the transient flow. After 7 generations, the method has identified a nozzle profile that certainly is a candidate for optimum solution. The constraints on the generality of this possible solution remain to be clarified.

  7. Amorphous silica scale in cooling waters

    Energy Technology Data Exchange (ETDEWEB)

    Midkiff, W.S.; Foyt, H.P.

    1976-01-01

    In 1968, most of the evaporation cooled recirculating water systems at Los Alamos Scientific Laboratory were nearly inoperable due to scale. These systems, consisting of cooling towers, evaporative water coolers, evaporative condensers, and air washers had been operated on continuous blowdown without chemical treatment. The feedwater contained 80 mg/l silica. A successful program of routine chemical addition in the make-up water was begun. Blends of chelants, dispersants and corrosion inhibitors were found to gradually remove old scale, prevent new scale, and keep corrosion to less than an indicated rate of one mil per year. An explanation has been proposed that amorphous silica by itself does not form a troublesome scale. When combined with a crystal matrix such as calcite, the resultant silica containing scale can be quite troublesome. Rapid buildup of silica containing scale can be controlled and prevented by preventing formation of crystals from other constituents in the water such as hardness or iron. (auth)

  8. Control of corrosion product transport in PWR secondary cycles

    Energy Technology Data Exchange (ETDEWEB)

    Sawochka, S.G.; Pearl, W.L. [NWT Corp., San Josa, CA (United States); Passell, T.O.; Welty, C.S. [Electric Power Research Institute, Palo Alto, CA (United States)

    1992-12-31

    Transport of corrosion products to PWR steam generators by the feedwater leads to sludge buildup on the tubesheets and fouling of tube-to-tube support crevices. In these regions, chemical impurities concentrate and accelerate tubing corrosion. Deposit buildup on the tubes also can lead to power generation limitations and necessitate chemical cleaning. Extensive corrosion product transport data for PWR secondary cycles has been developed employing integrating sampling techniques which facilitate identification of major corrosion product sources and assessments of the effectiveness of various control options. Plant data currently are available for assessing the impact of factors such as pH, pH control additive, materials of construction, blowdown, condensate treatment, and high temperature drains and feedwater filtration.

  9. Modeling in fast dynamics of accidents in the primary circuit of PWR type reactors; Modelisation en dynamique rapide d'accidents dans le circuit primaire des reacteurs a eau pressurisee

    Energy Technology Data Exchange (ETDEWEB)

    Robbe, M.F

    2003-12-01

    Two kinds of accidents, liable to occur in the primary circuit of a Pressurized Water Reactor and involving fast dynamic phenomena, are analyzed. The Loss Of Coolant Accident (LOCA) is the accident used to define the current PWR. It consists in a large-size break located in a pipe of the primary circuit. A blowdown wave propagates through the circuit. The pressure differences between the different zones of the reactor induce high stresses in the structures of the lower head and may degrade the reactor core. The primary circuit starts emptying from the break opening. Pressure decreases very quickly, involving a large steaming. Two thermal-hydraulic simulations of the blowdown phase of a LOCA are computed with the Europlexus code. The primary circuit is represented by a pipe-model including the hydraulic peculiarities of the circuit. The main differences between both computations concern the kind of reactor, the break location and model, and the initialization of the accidental operation. Steam explosion is a hypothetical severe accident liable to happen after a core melting. The molten part of the core (called corium) falls in the lower part of the reactor. The interaction between the hot corium and the cold water remaining at the bottom of the vessel induces a massive and violent vaporization of water, similar to an explosive phenomenon. A shock wave propagates in the vessel. what can damage seriously the neighbouring structures or drill the vessel. This work presents a synthesis of in-vessel parametrical studies carried out with the Europlexus code, the linkage of the thermal-hydraulic code Mc3d dedicated to the pre-mixing phase with the Europlexus code dealing with the explosion, and finally a benchmark between the Cigalon and Europlexus codes relative to the Vulcano mock-up. (author)

  10. State waste discharge permit application for the 200 Area Effluent Treatment Facility and the State-Approved Land Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    Application is being made for a permit pursuant to Chapter 173--216 of the Washington Administrative Code (WAC), to discharge treated waste water and cooling tower blowdown from the 200 Area Effluent Treatment Facility (ETF) to land at the State-Approved Land Disposal Site (SALDS). The ETF is located in the 200 East Area and the SALDS is located north of the 200 West Area. The ETF is an industrial waste water treatment plant that will initially receive waste water from the following two sources, both located in the 200 Area on the Hanford Site: (1) the Liquid Effluent Retention Facility (LERF) and (2) the 242-A Evaporator. The waste water discharged from these two facilities is process condensate (PC), a by-product of the concentration of waste from DSTs that is performed in the 242-A Evaporator. Because the ETF is designed as a flexible treatment system, other aqueous waste streams generated at the Hanford Site may be considered for treatment at the ETF. The origin of the waste currently contained in the DSTs is explained in Section 2.0. An overview of the concentration of these waste in the 242-A Evaporator is provided in Section 3.0. Section 4.0 describes the LERF, a storage facility for process condensate. Attachment A responds to Section B of the permit application and provides an overview of the processes that generated the wastes, storage of the wastes in double-shell tanks (DST), preliminary treatment in the 242-A Evaporator, and storage at the LERF. Attachment B addresses waste water treatment at the ETF (under construction) and the addition of cooling tower blowdown to the treated waste water prior to disposal at SALDS. Attachment C describes treated waste water disposal at the proposed SALDS.

  11. Axisymmetric Numerical Modeling of Pulse Detonation Rocket Engines

    Science.gov (United States)

    Morris, Christopher I.

    2005-01-01

    Pulse detonation rocket engines (PDREs) have generated research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional rocket engines. The detonative mode of combustion employed by these devices offers a thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional rocket engines and gas turbines. However, while this theoretical advantage has spurred considerable interest in building PDRE devices, the unsteady blowdown process intrinsic to the PDRE has made realistic estimates of the actual propulsive performance problematic. The recent review article by Kailasanath highlights some of the progress that has been made in comparing the available experimental measurements with analytical and numerical models. In recent work by the author, a quasi-one-dimensional, finite rate chemistry CFD model was utilized to study the gasdynamics and performance characteristics of PDREs over a range of blowdown pressure ratios from 1-1000. Models of this type are computationally inexpensive, and enable first-order parametric studies of the effect of several nozzle and extension geometries on PDRE performance over a wide range of conditions. However, the quasi-one-dimensional approach is limited in that it cannot properly capture the multidimensional blast wave and flow expansion downstream of the PDRE, nor can it resolve nozzle flow separation if present. Moreover, the previous work was limited to single-pulse calculations. In this paper, an axisymmetric finite rate chemistry model is described and utilized to study these issues in greater detail. Example Mach number contour plots showing the multidimensional blast wave and nozzle exhaust plume are shown. The performance results are compared with the quasi-one-dimensional results from the previous paper. Both Euler and Navier-Stokes solutions are calculated in order to determine the effect of viscous

  12. SPREE: A Successful Seismic Array by a Failed Rift System; Analysis of Seismic Noise in the Seismically Quiet Mid-continent

    Science.gov (United States)

    Wolin, E.; van der Lee, S.; Bollmann, T. A.; Revenaugh, J.; Aleqabi, G. I.; Darbyshire, F. A.; Frederiksen, A. W.; Wiens, D.; Shore, P.

    2014-12-01

    The Superior Province Rifting Earthscope Experiment (SPREE) completed its field recording phase last fall with over 96% data return. While 60% of the stations returned data 100% of the time, only 9 performed below 90% and one station had questionable timing. One station was vandalized, another stolen. One station continued recording after its solar panels were pierced by a bullet, while another two stations survived a wildfire and a blow-down, respectively. The blow-down was an extreme wind event that felled hundreds of thousands of trees around the station. SPREE stations recorded many hundreds of earthquakes. Two regional earthquakes and over 400 teleseismic earthquakes had magnitudes over 5.5 and three, smaller local earthquakes had magnitudes over 2.5. We have calculated power spectral estimates between 0.1-1000 s period for the ~2.5-year lifespan of all 82 SPREE stations. Vertical channels performed quite well across the entire frequency range, falling well below the high noise model of Peterson (1993) and usually within 10-15 dB of nearby Transportable Array stations. SPREE stations' horizontal components suffer from long-period (> 30 s) noise. This noise is quietest at night and becomes up to 30 dB noisier during the day in the summer months. We explore possible causes of this variation, including thermal and atmospheric pressure effects. One possibility is that stations are insulated by snow during the winter, reducing temperature variations within the vault. Spring snowmelt creates instability at many of the SPREE stations, evidenced by frequent recenterings and enhanced long-period noise. For all channels, power in the microseismic band (4-16 s) is strongest in the winter, corresponding to storm season in the Northern Hemisphere, and approximately 20 dB weaker during the summer. The power spectrum and temporal variation of microseismic energy is consistent across the entire SPREE array.

  13. Generalization of experimental data on amplitude and frequency of oscillations induced by steam injection into a subcooled pool

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, Walter; Li, Hua [Division of Nuclear Power Safety, Royal Institute of Technology (KTH), Roslagstullsbacken 21, SE-10691 Stockholm (Sweden); Puustinen, Markku [Nuclear Engineering, LUT School of Energy Systems, Lappeenranta University of Technology (LUT), FIN-53851 Lappeenranta (Finland); Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se [Division of Nuclear Power Safety, Royal Institute of Technology (KTH), Roslagstullsbacken 21, SE-10691 Stockholm (Sweden)

    2015-12-15

    Highlights: • Available data on steam injection into subcooled pool is generalized. • Scaling approach is proposed on amplitude and frequency of chugging oscillations. • The scaled amplitude has a maximum at Froude number Fr ≈ 2.8. • The scaled frequency has a minimum at Fr ≈ 6. • Both amplitude and frequency has a strong dependence on pool bulk temperature. - Abstract: Steam venting and condensation into a subcooled pool of water through a blowdown pipe can undergo a phenomenon called chugging, which is an oscillation of the steam–water interface inside the blowdown pipe. The momentum that is generated by the oscillations is directly proportional to the oscillations’ amplitude and frequency, according to the synthetic jet theory. Higher momentum can enhance pool mixing and positively affect the pool's pressure suppression capacity by reducing thermal stratification. In this paper, we present a generalization of available experimental data on the amplitude and frequency of oscillations during chugging. We use experimental data obtained in different facilities at different scales to suggest a scaling approach for non-dimensional amplitude and frequency of the oscillations. We demonstrate that the Froude number Fr (which relates the inertial forces to gravitational forces) can be used as a scaling criterion in this case. The amplitude has maximum at Fr ≈ 2.8. There is also a strong dependence of the amplitude on temperature; the lower the bulk temperature is the higher the scaled amplitude. A known analytical theory can only capture the decreasing trend in amplitude for Fr > 2.8 and fails to capture the increasing trend and the temperature dependence. Similarly, there is a minimum of the non-dimensional frequency at Fr ≈ 6. A strong dependence on temperature is also observed for Fr > 6; the lower the bulk temperature is the higher the scaled frequency. The known analytical theory is able to capture qualitatively the general trend in

  14. Thermal-hydraulic analysis for changing feedwater check valve leakage rate testing methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, R.; Harrell, J.

    1996-12-01

    The current design and testing requirements for the feedwater check valves (FWCVs) at the Grand Gulf Nuclear Station are established from original licensing requirements that necessitate extremely restrictive air testing with tight allowable leakage limits. As a direct result of these requirements, the original high endurance hard seats in the FWCVs were modified with elastomeric seals to provide a sealing surface capable of meeting the stringent air leakage limits. However, due to the relatively short functional life of the elastomeric seals compared to the hard seats, the overall reliability of the sealing function actually decreased. This degraded performance was exhibited by frequent seal failures and subsequent valve repairs. The original requirements were based on limited analysis and the belief that all of the high energy feedwater vaporized during the LOCA blowdown. These phenomena would have resulted in completely voided feedwater lines and thus a steam environment within the feedwater leak pathway. To challenge these criteria, a comprehensive design basis accident analysis was developed using the RELAP5/MOD3.1 thermal-hydraulic code. Realistic assumptions were used to more accurately model the post-accident fluid conditions within the feedwater system. The results of this analysis demonstrated that no leak path exists through the feedwater lines during the reactor blowdown phase and that sufficient subcooled water remains in various portions of the feedwater piping to form liquid water loop seals that effectively isolate this leak path. These results provided the bases for changing the leak testing requirements of the FWCVs from air to water. The analysis results also established more accurate allowable leakage limits, determined the real effective margins associated with the FWCV safety functions, and led to design changes that improved the overall functional performance of the valves.

  15. CFD simulation of air discharge tests in the PPOOLEX facility

    Energy Technology Data Exchange (ETDEWEB)

    Tanskanen, V.; Puustinen, M. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2008-07-15

    This report summarizes the CFD simulation results of two air discharge tests of the characterizing test program in 2007 with the scaled down PPOOLEX facility. Air was blown to the dry well compartment and from there through a DN200 blowdown pipe into the condensation pool (wet well). The selected tests were modeled with Fluent CFD code. Test CHAR-09-1 was simulated to 28.92 seconds of real time and test CHAR-09-3 to 17.01 seconds. The VOF model was used as a multiphase model and the standard k epsilon-model as a turbulence model. Occasional convergence problems, usually at the beginning of bubble formation, required the use of relatively short time stepping. The simulation time costs threatened to become unbearable since weeks or months of wall-clock time with 1-2 processors were needed. Therefore, the simulated time periods were limited from the real duration of the experiments. The results obtained from the CFD simulations are in a relatively good agreement with the experimental results. Simulated pressures correspond well to the measured ones and, in addition, fluctuations due to bubble formations and breakups are also captured. Most of the differences in temperature values and in their behavior seem to depend on the locations of the measurements. In the vicinity of regions occupied by water in the experiments, thermocouples getting wet and drying slowly may have had an effect on the measured temperature values. Generally speaking, most temperatures were simulated satisfyingly and the largest discrepancies could be explained by wetted thermocouples. However, differences in the dry well and blowdown pipe top measurements could not be explained by thermocouples getting wet. Heat losses and dry well / wet well heat transfer due to conduction have neither been estimated in the experiments nor modeled in the simulations. Estimation of heat conduction and heat losses should be carried out in future experiments and they should be modeled in future simulations, too. (au)

  16. RELAP5/MOD3 assessment using the Semiscale 50% Feed Line Break test S-FS-11

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.J.; Chung, B.D.; Kim, H.J. [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)

    1993-06-01

    The RELAP5/MOD3 5m5 code was assessed using the 1/1705 volume scaled Semiscale 50% Feed Line Break (FLB) test S-FS-11. Test S-FS-11 was designed in three phases: (a) blowdown phase, (b) stabilization phase, and (c) refill phase. The first objective was to assess the code applicability to 50% FLB situation, the second was to evaluate the FSAR conservatisms regarding SG heat transfer degradation, steam line check valve failure, break flow state, and peak primary system pressure, and the third was to validate the EOP effectiveness. The code was able to simulate the major T/H parameters except for the two-phase break flow and the secondary convective heat transfer rate. The two-phase break flow had still deficiencies. The current boiling heat transfer rate was developed from the data for flow inside of a heated tube, not for flow around heated tubes in a tube bundle. Results indicated that the assumption of 100% heat transfer until the liquid inventory depletion was not conservative, the failed affected steam generator main steam line check valve assumption was not either conservative, the measured break flow experienced all types of flow conditions, the relative proximity to the 110% design pressure limit was conservative. The automatic actions during the blowdown phase were effective in mitigating the consequences. The stabilization operation performed by operator actions were effective to permit natural circulation cooldown and depressurization. The voided secondary refill operations also verified the effectiveness of the operations while recovering the inventory in a voided steam generator.

  17. Assessment of the CATHARE 3-D module for LBLOCA simulation

    Energy Technology Data Exchange (ETDEWEB)

    Pascal Bazin; Isabelle Dor; Christophe Morel [Commissariat a l' Energie Atomique, CEA - GRENOBLE, 17 rue des Martyrs, 38054 GRENOBLE cedex 9 (France)

    2005-07-01

    Full text of publication follows: CATHARE is a best-estimate system code developed by CEA, EDF, FRAMATOME-ANP and IRSN for PWR safety analysis, accident management, definition of plant operating procedure and for research and development. It is also used to quantify conservative margins and for licensing. In the framework of Pressurized Water Reactor (PWR) safety studies, Large Break Loss-Of-Coolant Accident (LB LOCA) prediction is still one of the most important and one of the most difficult problem. The three main phases of a LB LOCA are respectively the blowdown, the refilling and the reflooding phases. During the blowdown, the lower plenum voiding results in water entrainment towards the break by steam flowing from the core. Because of the core radial profile, critical heat flux occur but a nonuniform quenching may take place, which results in a 3-D repartition of the energy stored in the core at the beginning of the reflooding. The refilling phase which starts at the accumulator discharge encounters very complex thermalhydraulic phenomena: very strong condensation which induces instabilities, presence of nitrogen degassing from accumulator water which may have an important effect on the transient, countercurrent flow limitation which occurs in the complex geometry of the annular downcomer. The reflooding phase initial conditions in the core are therefore very non-uniform. The presence of buoyancy driven transverse flows below the quench front assures a very efficient mixing between the fuel assemblies. The quench front progression in the hot assemblies is accelerated by pre-cooling due to water cross-flows just above the quench front. Therefore the clad temperature excursion is moderated in the hot assemblies by an increased water carry-over coming partially from colder assemblies. All these multi-dimensional aspects create a very challenging problem for the CATHARE 3-D module. A good prediction of the lower plenum voiding altogether with the amount of

  18. Alternative cooling water flow path for RHR heat exchanger and its effect on containment response during extended station blackout for Chinshan BWR-4 plant

    Energy Technology Data Exchange (ETDEWEB)

    Yuann, Yng-Ruey, E-mail: ryyuann@iner.gov.tw

    2016-04-15

    Highlights: • Motivating alternative RHR heat exchanger tube-side flow path and determining required capacity. • Calculate NSSS and containment response during 24-h SBO for Chinshan BWR-4 plant. • RETRAN and GOTHIC models are developed for NSSS and containment, respectively. • Safety relief valve blowdown flow and energy to drywell are generated by RETRAN. • Analyses are performed with and without reactor depressurization, respectively. - Abstract: The extended Station Blackout (SBO) of 24 h has been analyzed with respect to the containment response, in particular the suppression pool temperature response, for the Chinshan BWR-4 plant of MARK-I containment. The Chinshan plant, owned by Taiwan Power Company, has twin units with rated core thermal power of 1840 MW each. The analysis is aimed at determining the required alternative cooling water flow capacity for the residual heat removal (RHR) heat exchanger when its tube-side sea water cooling flow path is blocked, due to some reason such as earthquake or tsunami, and is switched to the alternative raw water source. Energy will be dissipated to the suppression pool through safety relief valves (SRVs) of the main steam lines during SBO. The RETRAN model is used to calculate the Nuclear Steam Supply System (NSSS) response and generate the SRV blowdown conditions, including SRV pressure, enthalpy, and mass flow rate. These conditions are then used as the time-dependent boundary conditions for the GOTHIC code to calculate the containment pressure and temperature response. The shaft seals of the two recirculation pumps are conservatively assumed to fail due to loss of seal cooling and a total leakage flow rate of 36 gpm to the drywell is included in the GOTHIC model. Based on the given SRV blowdown conditions, the GOTHIC containment calculation is performed several times, through the adjustment of the heat transfer rate of the RHR heat exchanger, until the criterion that the maximum suppression pool temperature

  19. Calibration of a four-hole pyramid probe and area traverse measurements in a short-duration transonic turbine cascade tunnel

    Science.gov (United States)

    Main, A. J.; Day, C. R. B.; Lock, G. D.; Oldfield, M. L. G.

    1996-08-01

    A four-hole pyramid probe has been calibrated for use in a short-duration transonic turbine cascade tunnel. The probe is used to create area traverse maps of total and static pressure, and pitch and yaw angles of the flow downstream of a transonic annular cascade. This data is unusual in that it was acquired in a short-duration (5 s of run time) annular cascade blowdown tunnel. A four-hole pyramid probe was used which has a 2.5 mm section head, and has the side faces inclined at 60° to the flow to improve transonic performance. The probe was calibrated in an ejector driven, perforated wall transonic tunnel over the Mach number range 0.5 1.2, with pitch angles from -20° to + 20° and yaw angles from-23° to +23°. A computer driven automatic traversing mechanism and data collection system was used to acquire a large probe calibration matrix (˜ 10,000 readings) of non dimensional pitch, yaw, Mach number, and total pressure calibration coefficients. A novel method was used to transform the probe calibration matrix of the raw coefficients into a probe application matrix of the physical flow variables (pitch, yaw, Mach number etc.). The probe application matrix is then used as a fast look-up table to process probe results. With negligible loss of accuracy, this method is faster by two orders of magnitude than the alternative of global interpolation on the raw probe calibration matrix. The blowdown tunnel (mean nozzle guide vane blade ring diameter 1.1 m) creates engine representative Reynolds numbers, transonic Mach numbers and high levels (≈ 13%) of inlet turbulence intensity. Contours of experimental measurements at three different engine relevant conditions and two axial positions have been obtained. An analysis of the data is presented which includes a necessary correction for the finite velocity of the probe. Such a correction is non trivial for the case of fast moving probes in compressible flow.

  20. Field enhancements of packed-bed performance for low-concentration acidic and basic-waste gases from semiconductor manufacturing process.

    Science.gov (United States)

    Chein, Hung Min; Aggarwal, Shankar Gopala; Wu, Hsin Hsien; Chen, Tzu Ming; Huang, Chun-Chao

    2005-05-01

    Low-concentration acidic and basic-waste gas pollutants contribute significantly in the total emission of a facility. Previous results show that the control of high volumetric flow rate (approximately 500 m3/min), low-concentration acidic (< 1 ppm by vol) and basic (< 3 ppm by vol) gases from semiconductor process vent, by conventional wet scrubbing technique is a challenging task. This work was targeted to enhance the performance of packed beds for high-volumetric flow rate, low-concentration acidic (HF, HCl), and basic (NH3)-waste gases from the semiconductor manufacturing process. The methodology used to meet the goal was the application of fine-water mist over the inlet stream before entering to the packed bed and use of the surfactant with mist/packed-bed liquid in low concentration. An experimental study was carried out in two acid-packed beds to optimize the operating conditions, such as pH of the liquid, circulating liquid flow rate, blow-down cycle, and so forth. The relationship among liquid pH, liquid ionic concentration, and the removal efficiency of the packed bed for the pollutants has been discussed considering chemical equilibrium, two-film theory, and Henry's law. For the potential utilization of scrubbing water, the dependency of the efficiency on blow-down cycle was studied, and a mechanism is suggested. The proposed water-mist surfactant system was installed in two acid-packed beds, and performance of the packed beds was compared. The background efficiencies of the acid-packed beds for HF, HCl, and NH3 were found max to be (n = 11) 53, 40, and 27%, whereas after installation of the system, they increased significantly and became 76 +/- 13% (n = 10), 76 +/- 8% (n = 7), and 78 +/- 7% (n = 7), respectively, for inlet concentrations of HF and HCl < 1 ppm and NH3 < 14 ppm. The mechanism by which the surfactants operate to enhance the removal in scrubbing process is suggested considering the hydrodynamic effect and the interfacial effect with the

  1. PPOOLEX experiments on thermal stratification and mixing

    Energy Technology Data Exchange (ETDEWEB)

    Puustinen, M.; Laine, J.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2009-08-15

    The results of the thermal stratification experiments in 2008 with the PPOOLEX test facility are presented. PPOOLEX is a closed vessel divided into two compartments, dry well and wet well. Extra temperature measurements for capturing different aspects of the investigated phenomena were added before the experiments. The main purpose of the experiment series was to generate verification data for evaluating the capability of GOTHIC code to predict stratification and mixing phenomena. Altogether six experiments were carried out. Heat-up periods of several thousand seconds by steam injection into the dry well compartment and from there into the wet well water pool were recorded. The initial water bulk temperature was 20 deg. C. Cooling periods of several days were included in three experiments. A large difference between the pool bottom and top layer temperature was measured when small steam flow rates were used. With higher flow rates the mixing effect of steam discharge delayed the start of stratification until the pool bulk temperature exceeded 50 deg. C. The stratification process was also different in these two cases. With a small flow rate stratification was observed only above and just below the blowdown pipe outlet elevation. With a higher flow rate over a 30 deg. C temperature difference between the pool bottom and pipe outlet elevation was measured. Elevations above the pipe outlet indicated almost linear rise until the end of steam discharge. During the cooling periods the measurements of the bottom third of the pool first had an increasing trend although there was no heat input from outside. This was due to thermal diffusion downwards from the higher elevations. Heat-up in the gas space of the wet well was quite strong, first due to compression by pressure build-up and then by heat conduction from the hot dry well compartment via the intermediate floor and test vessel walls and by convection from the upper layers of the hot pool water. The gas space

  2. Characterizing experiments of the PPOOLEX test facility

    Energy Technology Data Exchange (ETDEWEB)

    Puustinen, M.; Laine, J. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2008-07-15

    This report summarizes the results of the characterizing test series in 2007 with the scaled down PPOOLEX facility designed and constructed at Lappeenranta University of Technology. Air and steam/air mixture was blown into the dry well compartment and from there through a DN200 blowdown pipe to the condensation pool (wet well). Altogether eight air and four steam/air mixture experiments, each consisting of several blows (tests), were carried out. The main purpose of the experiment series was to study the general behavior of the facility and the performance of basic instrumentation. Proper operation of automation, control and safety systems was also tested. The test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. The facility is equipped with high frequency measurements for capturing different aspects of the investigated phenomena. The general behavior of the PPOOLEX facility differs significantly from that of the previous POOLEX facility because of the closed two-compartment structure of the test vessel. Heat-up by several tens of degrees due to compression in both compartments was the most obvious evidence of this. Temperatures also stratified. Condensation oscillations and chugging phenomenon were encountered in those tests where the fraction of non-condensables had time to decrease significantly. A radical change from smooth condensation behavior to oscillating one occurred quite abruptly when the air fraction of the blowdown pipe flow dropped close to zero. The experiments again demonstrated the strong diminishing effect that noncondensable gases have on dynamic unsteady loadings experienced by submerged pool structures. BWR containment like behavior related to the beginning of a postulated steam line break accident was observed in the PPOOLEX test facility during the steam/air mixture experiments. The most important task of the research project, to produce experimental data for code simulation purposes, can be

  3. Research and development for decontamination system of spent resin in Hanbit Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Gi Hong [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of)

    2015-12-15

    When reactor coolant leaks occur due to cracks of a steam generator tube, radioactive materials contained in the primary cooling water in nuclear power plant are forced out toward the secondary systems. At this time the secondary water purification resin in the ion exchange resin tower of the steam generator blowdown system is contaminated by the radioactivity of the leaked radioactive materials, so we pack this in special containers and store temporarily because we could not dispose it by ourselves. If steam generator tube leakage occurs, it produces contaminated spent resins annually about 5,000-7,000 liters. This may increase the amount of nuclear waste productions, a disposal working cost and a unit price of generating electricity in the plant. For this reasons, it is required to develop a decontamination process technique for reducing the radioactive level of these resins enough to handle by the self-disposal method. In this research, First, Investigated the structure and properties of the ion exchange resin used in a steam generator blowdown system. Second, Checked for a occurrence status of contaminated spent resin and a disposal technology. Third, identified the chemical characteristics of the waste radionuclides of the spent resin, and examined ionic bonding and separation mechanism of radioactive nuclear species and a spent resin. Finally, we carried out the decontamination experiment using chemicals, ultrasound, microbubbles, supercritical carbon dioxide to process these spent resin. In the case of the spent resin decontamination method using chemicals, the higher the concentration of the drug decontamination efficiency was higher. In the ultrasound method, foreign matter of the spent resin was removed and was found that the level of radioactivity is below of the MDA. In the microbubbles method, we found that the concentration of the radioactivity decreased after the experiment, so it can be used to the decontamination process of the spent resin. In

  4. PPOOLEX experiments on stratification and mixing in the wet well pool

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M.; Raesaenen, A.; Tanskanen, V. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2011-03-15

    This report summarizes the results of the thermal stratification and mixing experiments carried out in 2010 with the scaled down, two compartment PPOOLEX test facility designed and constructed at LUT. Steam was blown into the thermally insulated dry well compartment and from there through the DN200 vertical blowdown pipe to the condensation pool filled with sub-cooled water. The main purpose of the experiment series was to generate verification data for evaluating the capability of GOTHIC and APROS codes to predict stratification and mixing phenomena. Another objective was to test the sound velocity measurement system. Altogether five experiments were carried out. The experiments consisted of a small steam flow rate stratification period and of a mixing period with continuously or stepwise increasing flow rate. The dry well structures were heated up to the level of approximately 90 deg. C before the actual experiments. The initial water bulk temperature was 20 deg. C. When the steam flow rate was low enough (typically approx100-150 g/s) temperatures below the blowdown pipe outlet remained constant while increasing heat-up occurred towards the pool surface layers indicating strong thermal stratification of the wet well pool water. During the stratification period the highest measured temperature difference between pool bottom and surface was approximately 40 deg. C. During the mixing period total mixing of the pool volume was not achieved in any of the experiments. The bottom layers heated up significantly but never reached the same temperature as the topmost layers. The lowest measured temperature difference between the pool bottom and surface was 7-8 deg. C. According to the test results, it seems that a small void fraction doesn't have an effect on the speed of sound in water and that the acquired sound velocity measurement system cannot be used for the estimation of void fraction in the wet well water pool. However, more tests on this issue have to be

  5. Pressure and temperature analyses using GOTHIC for Mark I containment of the Chinshan Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yen-Shu, E-mail: yschen@iner.org.t [Nuclear Engineering Division, Institute of Nuclear Energy Research, 1000, Wenhua Rd., Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan (China); Yuann, Yng-Ruey; Dai, Liang-Che; Lin, Yon-Pon [Nuclear Engineering Division, Institute of Nuclear Energy Research, 1000, Wenhua Rd., Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan (China)

    2011-05-15

    Research highlights: The Chinshan Mark I containment pressure-temperature responses are analyzed. GOTHIC is used to calculate the containment responses under three pipe break events. This study is used to support the Chinshan Stretch Power Uprate (SPU) program. The calculated peak pressure and temperature are still below the design values. The Chinshan containment integrity can be maintained under SPU condition. - Abstract: Chinshan Nuclear Power Plant in Taiwan is a GE-designed twin-unit BWR/4 plant with original licensed thermal power (OLTP) of 1775 MWt for each unit. Recently, the Stretch Power Uprate (SPU) program for the Chinshan plant is being conducted to uprate the core thermal power to 1858 MWt (104.66% OLTP). In this study, the Chinshan Mark I containment pressure/temperature responses during LOCA at 105% OLTP (104.66% OLTP + 0.34% OLTP power uncertainty = 105% OLTP) are analyzed using the containment thermal-hydraulic program GOTHIC. Three kinds of LOCA (Loss of Coolant Accident) scenarios are investigated: Recirculation Line Break (RCLB), Main Steam Line Break (MSLB), and Feedwater Line Break (FWLB). In the short-term analyses, blowdown data generated by RELAP5 transient analyses are provided as boundary conditions to the GOTHIC containment model. The calculated peak drywell pressure and temperature in the RCLB event are 217.2 kPaG and 137.1 {sup o}C, respectively, which are close to the original FSAR results (219.2 kPaG and 138.4 {sup o}C). Additionally, the peak drywell temperature of 155.3 {sup o}C calculated by MSLB is presented in this study. To obtain the peak suppression pool temperature, a long-term RCLB analysis is performed using a simplified RPV (Reactor Pressure Vessel) volume to calculate blowdown flow rate. One RHR (Residual Heat Removal) heat exchanger is assumed to be inoperable for suppression pool cooling mode. The calculated peak suppression pool temperature is 93.2 {sup o}C, which is below the pool temperature used for evaluating the

  6. Development of CANDU ECCS performance evaluation methodology and guides

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Kwang Hyun; Park, Kyung Soo; Chu, Won Ho [Korea Maritime Univ., Jinhae (Korea, Republic of)

    2003-03-15

    The objectives of the present work are to carry out technical evaluation and review of CANDU safety analysis methods in order to assist development of performance evaluation methods and review guides for CANDU ECCS. The applicability of PWR ECCS analysis models are examined and it suggests that unique data or models for CANDU are required for the following phenomena: break characteristics and flow, frictional pressure drop, post-CHF heat transfer correlations, core flow distribution during blowdown, containment pressure, and reflux rate. For safety analysis of CANDU, conservative analysis or best estimate analysis can be used. The main advantage of BE analysis is a more realistic prediction of margins to acceptance criteria. The expectation is that margins demonstrated with BE methods would be larger that when a conservative approach is applied. Some outstanding safety analysis issues can be resolved by demonstration that accident consequences are more benign than previously predicted. Success criteria for analysis and review of Large LOCA can be developed by top-down approach. The highest-level success criteria can be extracted from C-6 and from them, the lower level criteria can be developed step-by-step, in a logical fashion. The overall objectives for analysis and review are to verify radiological consequences and frequency are met.

  7. Evaluation of organics removal options. A case study from a zero liquid discharge power plant

    Energy Technology Data Exchange (ETDEWEB)

    Quagraine, Emmanuel K.; Hill, Keith Dean; Omorogbe, Fredrick [Shand Power Station, Estevan (Canada)

    2010-01-15

    Although the role of organics in power plant cycle chemistry still appears to be controversial, their adverse effects in the course of makeup water treatment are very familiar and include fouling of ion exchange resins. This paper describes the organic/bio-fouling experience in a boiler makeup water treatment train for a zero liquid discharge plant, which draws on treated sewage water and surface water for cooling and utilizes the cooling tower blowdown to make distillate water from an evaporator prior to final treatment with a mixed bed demineralizer. In a case study, which is the focus of this paper, the performance of the pilot plants of two recommended organic removal techniques (i.e. reverse osmosis and organic trap resin) were compared to the existing activated carbon bed for organic removal prior to the mixed beds. Parameters evaluated for these three techniques (before and after each unit) include bacteria plate counts, organic carbons, inorganic nutrients (e.g. NH{sub 3}-N, [NO{sub 3}{sup -}+ NO{sub 2}{sup -}]-N, P, Mn, and Fe), known parameters that could significantly impact on the performance of the mixed beds (i.e. SiO{sub 2}, Cl{sup -}, SO{sub 4}{sup 2-}, Na{sup +}), and various others like pH, conductivity, turbidity, HCO{sub 3}{sup -} etc. The effects of oxidizing (i.e. bleach) and non-oxidizing (glutaraldehyde) biocides on the performance of the activated carbon filter were also evaluated.

  8. Research on the improvement of nuclear safety -The development of LOCA analysis codes for nuclear power plant-

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Won Pyo; Jung, Yung Jong; Kim, Kyung Doo; Jung, Jae Joon; Kim, Won Suk; Han, Doh Heui; Hah, Kooi Suk; Jung, Bub Dong; Lee, Yung Jin; Hwang, Tae Suk; Lee, Sang Yong; Park, Chan Uk; Choi, Han Rim; Lee, Sang Jong; Choi, Jong Hoh; Ban, Chang Hwan; Bae, Kyoo Hwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-07-01

    The present research aims at development of both a best estimate methodology on LOCA analysis and, as an application, performance analyses of safety systems. SBLOCA analyses have been continued to examine the capacity reduction effect of ECCS since the second project year. As a results, core uncovery, which is requirement of URD has not been occurred in 6`` cold leg break. Although core uncovery has been predicted when DVI line has been broken for DVI+4-Train HPIS, the calculated PCT has lied well within the criterion. The effect of safety injection position and SIT characteristics are also analyzed for LBLOCA. The results show that cold leg injection is the most effective way and the adaption of advanced SIT could lead to elimination of LPSI pump from the safety system. On the other hand, the quantified uncertainties obtained from THTF and FLECHT/SEASET which represents blowdown and reflood phenomena, respectively, have been confirmed using IET(LOFT test). The application uncertainty for Kori unit 3 has been analyzed. Finally, application of the best estimate methodology using the uncertainties concerned with the code, the bais, and the application, leads to overall uncertainty of about 200K for Kori unit 3. 244 figs, 22 tabs, 92 refs. (Author).

  9. Role of Nurse Logs in Forest Expansion at Timberline

    Science.gov (United States)

    Johnson, A. C.; Yeakley, A.

    2008-12-01

    Nurselogs, known to be key sites of forest regeneration in lower elevation temperate forests, may be important sites for seedling establishment at expanding timberline forests. To determine factors associated with seedling establishment and survival on nurselogs at timberline, fourteen sites, located across a precipitation gradient in the Washington North Cascades Mountains, were examined. Site attributes including seedling type and height, disturbance process introducing downed wood, wood decay type, shading, slope gradient, aspect, and temperature and water content of wood and adjacent soil were determined along 60 m long transects. Nurselogs were found at 13 out of 14 sites; sites typically associated with greater than 80% shade and downed wood having a high level of wood decay. Downed wood serving as nurselogs originated from blowdown, snow avalanches, and forest fires. In total, 46 of 136 downed wood pieces observed served as nurselogs. Seedlings on nurselogs included mountain hemlock (Tsuga mertensiana), Pacific silver fir (Abies amabilis), yellow cedar (Chamaecyparis nootkatensis), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and western larch (Larix occidentalis). Nurselogs had significantly higher temperatures (p = 0.015) and higher moisture contents (p = 0.019) than the adjacent soil. Per equal volumes weighed, nurselogs had on average of 23.8 g more water than the adjacent soil. Given predictions of climate warming and associated summer drought conditions in Pacific Northwest forests, the moisture provided by nurselogs may be integral for conifer survival and subsequent timberline expansion in some landscapes.

  10. Reducing ion exchange resins rad-wastes, experience at EDF PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Fene, G. [Rohm and Haas Co. (France); Hoffman, B. [Rohm and Haas Co. (United States)

    2002-07-01

    Life time of an ion exchange resin in a Nuclear Power Station (EDF PWR). At the end of its life, an ion exchange resin which has been used to treat radioactive streams becomes a radwaste itself. Its level of radioactivity depends on the point of use and consequently on the circuit where it was used. Roughly speaking, in a Nuclear Power Station PWR we can consider two types of radwaste families: High radioactive family Ion exchange resins which come from primary circuit: reactor control and storage pools. Ion exchange resins which have worked in a decontamination circuit: waste water treatment. Low radioactive family Ion exchange resins which come from secondary circuit: Steam Generator Blowdown By understanding and carefully applying some critical properties of ion exchange resins, such as total capacity, selectivity, and physical structure, it is possible for nuclear power stations to minimize radwaste volumes, while at the same time improving plant performance. This type of improvement can be facilitated by close cooperation and communication between the resin producer and the nuclear power user. (authors)

  11. Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

    Science.gov (United States)

    Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

    2012-02-01

    Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality.

  12. Time-resolved flowfield measurements in a turbine stage

    Science.gov (United States)

    Holt, J. L.

    1985-06-01

    Time-resolved flowfield measurements for a 0.5-meter diameter, high work transonic turbine have been completed in the MIT Turbine Blowdown Facility (TBF). Measurements were taken: to determine the blade-to-blade total temperature profile for comparison with predictions from the Euler turbine equation; to determine the effect of using time-averaged pressures to calculate turbine performance; and to provide a complete set of time-resolved turbine stage data. A preliminary objective (given a 6 kHz blade passing frequency) was to determine the frequency response characteristics of the instrumentation used to make the flowfield measurements. A shock tube was built for this purpose. Measurements were taken with high-frequency response instrumentation including a dual-hot-wire aspirating probe, a four-way angle probe, and two cobra head total pressure probes incorporating silicon diaphragm pressure transducers. The aspirating probe is found to have a natural frequency of 15.5 kHz in the test gas with a damping ratio of 0.36; the angle probe a characteristic frequency of 45 kHz with a settling time of 18 usec. Both results are satisfactory for application in the TBF. The measured total temperature profile shows a peak-to-peak variation of 65 C (20%) and a characteristic frequency twice that of the blade passing frequency.

  13. Experiment data report for LOFT nonnuclear Test L1-4. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Batt, D. L.

    1977-07-01

    Test L1-4 was the fourth in a series of five nonnuclear isothermal blowdown tests conducted by the Loss of Fluid Test (LOFT) Program. Test L1-4 was the first Nuclear Regulatory Commission standard problem (International Problem No. 5 and U.S. Problem No. 7) experiment conducted at LOFT. Data from this test will be compared with predictions generated by the standard problem participants. For this test the LOFT Facility was configured to simulate a loss-of-coolant accident in a large pressurized water reactor resulting from a 200% double-ended offset shear break in a cold leg of the primary coolant system. A hydraulic core simulator assembly was installed in place of the nuclear core. The initial conditions in the primary coolant system intact loop were temperature at 279/sup 0/C, gauge pressure at 15.65 MPa, and intact loop flow at 268.4 kg/s. During system depressurization into a simulated containment, emergency core cooling water was injected into the primary coolant system cold leg to provide data on the effects of emergency core cooling on system thermalhydraulic response.

  14. Preliminary measurements of aerodynamic damping of a transonic compressor rotor

    Science.gov (United States)

    Crawley, E. F.; Kerrebrock, J. L.; Dugundji, J.

    1980-01-01

    The aeroelastic behavior of a transonic compressor rotor operated in the MIT Blowdown Compressor Facility has been examined by means of piezoelectric motion sensors at the base of each of the 23 blades. Excitation has been observed due to rotating stall, due to an incipient flutter, and due to the facility startup transient. A method has been found for determining the aerodynamic damping force by modal analysis of the blade motion. Application of this technique to the example of excitation by rotating stall has led to the conclusions that the blade loading decreases in the stall cell, and that the damping force on the blades in the clean flow is in phase with blade velocity but opposite it in sign, leading to a logarithmic decrement of 0.2. This method of force derivation has quite general applicability as it requires only blade motion data such as are routinely acquired with strain gages. It is argued that models are needed for aerodynamic damping which focus on the effects of near neighbors of a given blade, since flutter often results in large response of isolated blades or small groups of blades.

  15. Amazon old-growth forest wind disturbance and the regional carbon balance

    Science.gov (United States)

    Chambers, J. Q.; Negron Juarez, R. I.; Marra, D. M.; Roberts, D. A.; Hurtt, G. C.; Lima, A.; Higuchi, N.

    2010-12-01

    Estimating the carbon balance of a landscape is challenging. A key problem is determining whether or not measurements made in plots are representative of the carbon state of a larger region. A key parameter for calculating landscape carbon balance is the return frequency of episodic disturbances. If disturbances are clustered and occur more frequently than the time required for biomass recovery, a spatial mixture of patches in different stages of recovery occurs. Under these shifting steady-state mosaic conditions, quantifying the mean state of ecosystem attributes such as carbon balance or tree species diversity is difficult. In this study, satellite remote sensing (Landsat) was coupled with field investigations to create ~25 year landscape-scale disturbance chronosequence for old-growth forest in the Central Amazon. The detected disturbances were caused by strong storms which resulted in tree mortality events ranging from small clusters of 7-10 downed trees, to large contiguous blowdowns larger than 30 ha in size. Using the chronosequence, a cumulative probability distribution function was developed, which followed a power law, and was used to parameterize a forest carbon balance model. Results demonstrate that for power law exponents less than about 2.0, the spatial scale at which forest carbon balance establishes is much larger than generally expected. Ultimately, an increase in wind disturbance frequency and/or intensity with a warming climate has the potential to cause a net loss of carbon from Amazon forests to the atmosphere.

  16. Widespread Amazon forest tree mortality from a single cross-basin squall line event

    Science.gov (United States)

    Negrón-Juárez, Robinson I.; Chambers, Jeffrey Q.; Guimaraes, Giuliano; Zeng, Hongcheng; Raupp, Carlos F. M.; Marra, Daniel M.; Ribeiro, Gabriel H. P. M.; Saatchi, Sassan S.; Nelson, Bruce W.; Higuchi, Niro

    2010-08-01

    Climate change is expected to increase the intensity of extreme precipitation events in Amazonia that in turn might produce more forest blowdowns associated with convective storms. Yet quantitative tree mortality associated with convective storms has never been reported across Amazonia, representing an important additional source of carbon to the atmosphere. Here we demonstrate that a single squall line (aligned cluster of convective storm cells) propagating across Amazonia in January, 2005, caused widespread forest tree mortality and may have contributed to the elevated mortality observed that year. Forest plot data demonstrated that the same year represented the second highest mortality rate over a 15-year annual monitoring interval. Over the Manaus region, disturbed forest patches generated by the squall followed a power-law distribution (scaling exponent α = 1.48) and produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. Basin-wide, potential tree mortality from this one event was estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. Storm intensity is expected to increase with a warming climate, which would result in additional tree mortality and carbon release to the atmosphere, with the potential to further warm the climate system.

  17. Landscape analysis and pattern of hurricane impact and circulation on mangrove forests of the everglades

    Science.gov (United States)

    Doyle, T.W.; Krauss, K.W.; Wells, C.J.

    2009-01-01

    The Everglades ecosystem contains the largest contiguous tract of mangrove forest outside the tropics that were also coincidentally intersected by a major Category 5 hurricane. Airborne videography was flown to capture the landscape pattern and process of forest damage in relation to storm trajectory and circulation. Two aerial video transects, representing different topographic positions, were used to quantify forest damage from video frame analysis in relation to prevailing wind force, treefall direction, and forest height. A hurricane simulation model was applied to reconstruct wind fields corresponding to the ground location of each video frame and to correlate observed treefall and destruction patterns with wind speed and direction. Mangrove forests within the storm's eyepath and in the right-side (forewind) quadrants suffered whole or partial blowdowns, while left-side (backwind) sites south of the eyewall zone incurred moderate canopy reduction and defoliation. Sites along the coastal transect sustained substantially more storm damage than sites along the inland transect which may be attributed to differences in stand exposure and/or stature. Observed treefall directions were shown to be non-random and associated with hurricane trajectory and simulated forewind azimuths. Wide-area sampling using airborne videography provided an efficient adjunct to limited ground observations and improved our spatial understanding of how hurricanes imprint landscape-scale patterns of disturbance. ?? 2009 The Society of Wetland Scientists.

  18. DMAIC makes solutions possible at Surmont

    Energy Technology Data Exchange (ETDEWEB)

    Petkau, R.

    2010-09-15

    This article discussed how the Lean Six Sigma business management practice was successfully applied to solve a scaling problem at a steam-assisted gravity drainage (SAGD) facility operated by ConocoPhillips at Surmont. Lean Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of defects and minimizing variability. The Six Sigma method for the existing facility was executed by the define, measure, analyse, improve, and control (DMAIC) problem-solving process. The scaling problem was causing the company to spend too much and lose too much production. Pigging every 2 years was identified as the goal. In the measure stage, it was determined that bitumen in water was staying mostly in the generator. Oil field culture was identified as a hindrance to solving the scaling problem. Several other contributing factors were identified, including dissolved organics reduction, online turbidity meters, removing pH flush, flocculant system reliability, and blowdown recycle. Work is ongoing to reach the 24-month target. The most challenging part of the DMAIC process was system control, notably maintaining operations regardless of changes in company personnel. The company will continue using the Lean Six Sigma methodology to solve problems. 2 figs.

  19. RCGVS design improvement and depressurization capability tests for Ulchin nuclear power plant units 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Kang Sik; Seong, Ho Je; Jeong, Won Sang; Seo, Jong Tae; Lee, Sang Keun [Korea Power Engineering Company, Inc., Seoul (Korea, Republic of); Lim, Keun Hyo; Choi, Kwon Sik; Oh, Chul Sung [Korea Electric Power Cooperation, Taejon (Korea, Republic of)

    1998-12-31

    The Reactor Coolant Gas Vent System(RCGVS) design for Ulchin Nuclear Power Plant Units 3 and 4 (UCN 3 and 4) has been improved from the Yonggwang Nuclear Power Plant Units 3 and 4 (YGN 3 and 4) based on the evaluation results for depressurization capability tests performed at YGN 3 and 4. There has been a series of plant safety analyses for Natural Circulation Cooldown(NCC) event and thermo-dynamic analyses with RELAP5 code for the steam blowdown phenomena in order to optimize the orifice size of UCN 3 and 4 RCGVS. Based on these analyses results, the RCGVS orifics size for UCN 3 and 4 has been reduced to 9/32 inch from the 11/32 inch for YGN 3 and 4. The depressurization capability tests, which were performed at UCN 3 in order to verify the FSAR NCC analysis results, show that the RCGVS depressurization rates are being within the acceptable ranges. Therefore, it is concluded that the orificed flow path of UCN 3 and 4 RCGVS is adequately designed, and can provide the safety-grade depressurization capability required for a safe plant operation. 6 refs., 5 figs., 1 tab. (Author)

  20. Derecho Hazards in the United States.

    Science.gov (United States)

    Ashley, Walker S.; Mote, Thomas L.

    2005-11-01

    Convectively generated wind-storms occur over broad temporal and spatial scales; however, the more widespread and longer lived of these windstorms have been given the name "derecho." Utilizing an integrated derecho database, including 377 events from 1986 to 2003, this investigation reveals the amount of insured property losses, fatalities, and injuries associated with these windstorms in the United States. Individual derechos have been responsible for up to 8 fatalities, 204 injuries, forest blow-downs affecting over 3,000 km2 of timber, and estimated insured losses of nearly a $500 million. Findings illustrate that derecho fatalities occur more frequently in vehicles or while boating, while injuries are more likely to happen in vehicles or mobile homes. Both fatalities and injuries are most common outside the region with the highest derecho frequency. An underlying synthesis of both physical and social vulnerabilities is suggested as the cause of the unexpected casualty distribution. In addition, casualty statistics and damage estimates from hurricanes and tornadoes are contrasted with those from derechos to emphasize that derechos can be as hazardous as many tornadoes and hurricanes.

  1. Analysis of combustion performance and emission of extended expansion cycle and iEGR for low heat rejection turbocharged direct injection diesel engines

    Directory of Open Access Journals (Sweden)

    Shabir Mohd F.

    2014-01-01

    Full Text Available Increasing thermal efficiency in diesel engines through low heat rejection concept is a feasible technique. In LHR engines the high heat evolution is achieved by insulating the combustion chamber surfaces and coolant side of the cylinder with partially stabilized zirconia of 0.5 mm thickness and the effective utilization of this heat depend on the engine design and operating conditions. To make the LHR engines more suitable for automobile and stationary applications, the extended expansion was introduced by modifying the inlet cam for late closing of intake valve through Miller’s cycle for extended expansion. Through the extended expansion concept the actual work done increases, exhaust blow-down loss reduced and the thermal efficiency of the LHR engine is improved. In LHR engines, the formation of nitric oxide is more, to reduce the nitric oxide emission, the internal EGR is incorporated using modified exhaust cam with secondary lobe. Modifications of gas exchange with internal EGR resulted in decrease in nitric oxide emissions. In this work, the parametric studies were carried out both theoretically and experimentally. The combustion, performance and emission parameters were studied and were found to be satisfactory.

  2. Strategic elements of steam cycle chemistry control practices at TXU's Comanche Peak steam electric station

    Energy Technology Data Exchange (ETDEWEB)

    Fellers, B.; Stevens, J.; Nichols, G. [TXU Electric (United States)

    2002-07-01

    Early industry experience defined the critical importance of Chemistry Control Practices to maintaining long-term performance of PWR steam generators. These lessons provided the impetus for a number of innovations and alternate practices at Comanche Peak. For example, advanced amine investigations and implementation of results provided record low iron transport and deposition. The benefits of the surface-active properties of dimethyl-amine exceeded initial expectations. Operation of pre-coat polishers and steam generator blowdown demineralizers in the amine cycle enabled optimization of amine concentrations and stable pH control. The strategy for coordinated control of oxygen and hydrazine dosing complemented the advanced amine program for protective oxide stabilization. Additionally, a proactive chemical cleaning was performed on Unit 1 to prevent degradations from general fouling of steam generator tube-tube support plate (TSP) and top-of-tubesheet (TTS) crevices. This paper shares the results of these innovations and practices. Also, the bases, theory, and philosophy supporting the strategic elements of program will be presented. (authors)

  3. Basic investigation on promotion of joint implementation in fiscal 2000. Efficiency improvement project for district heat supplying plants in Dailian City in China; 2000 nendo kyodo jisshi nado suishin kiso chosa hokokusho. Chugoku/Dailian shi chiiki netsu kyokyu plant kokoritsu kaizen project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Investigations and discussions have been given on energy saving possibilities at two medium-sized heat and power supplying plants in the city of Dailian in China. The project will improve the operation methods of the heat and power plants so that the energy cost can be minimized, and attempt to improve the boiler heat efficiency and save the energy by means of heat recovery and utilization. The draft modification plan for energy conservation has planned operation optimization for energy conservation, control of boiler operation under variable pressure, modification of the external boiler heat converter, use of inverters for the large capacity motors for boilers, and recovery of heat from the boiler blow-down water. In the analysis, models were structured from the operation data, and the effects of applying the energy saving measures were derived from simulation. As a result, the energy saving effect was found to be about 13,000 tons at the Chunhai plant and about 7,000 tons at the Pulandian plant annually (converted to oil). The reduction in greenhouse gas emission was found to be about 40,000 tons at the Chunhai plant and about 20,000 tons at the Pulandian plant annually. The number of years for investment payback is about 4.1 years at the Chunhai plant, and about 4.9 years at the Pulandian plant, wherein good profitability can be estimated. (NEDO)

  4. Latest design of gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Kurzhofer, U.; Stolte, J.; Weyand, M.

    1996-12-01

    Babcock Sempell, one of the most important valve manufacturers in Europe, has delivered valves for the nuclear power industry since the beginning of the peaceful application of nuclear power in the 1960s. The latest innovation by Babcock Sempell is a gate valve that meets all recent technical requirements of the nuclear power technology. At the moment in the United States, Germany, Sweden, and many other countries, motor-operated gate and globe valves are judged very critically. Besides the absolute control of the so-called {open_quotes}trip failure,{close_quotes} the integrity of all valve parts submitted to operational forces must be maintained. In case of failure of the limit and torque switches, all valve designs have been tested with respect to the quality of guidance of the gate. The guidances (i.e., guides) shall avoid a tilting of the gate during the closing procedure. The gate valve newly designed by Babcock Sempell fulfills all these characteristic criteria. In addition, the valve has cobalt-free seat hardfacing, the suitability of which has been proven by friction tests as well as full-scale blowdown tests at the GAP of Siemens in Karlstein, West Germany. Babcock Sempell was to deliver more than 30 gate valves of this type for 5 Swedish nuclear power stations by autumn 1995. In the presentation, the author will report on the testing performed, qualifications, and sizing criteria which led to the new technical design.

  5. Investigations on multicycle spray detonations

    Institute of Scientific and Technical Information of China (English)

    LI Mu; YAN Chuanjun; ZHENG Longxi; WANG Zhiwu; QIU Hua

    2007-01-01

    Experimental investigations were carried out on a 50-I.D. Multicycle pulse detonation engine (PDE) model, and liquid fuel (gasoline) was used. The average of pressure peak, as measured by piezoelectricity pressure transducer, increased versus distance to thrust wall before fully-developed detonation came into being. According to the pressure history, the pressure in detonation tube would not rise abruptly until the flame front advanced a certain distance downstream the spark. Just at that moment, two compression waves spreading to opposite direction were formed. One was enforced by combustion and became detonation rapidly. The other was weakened because of obstacles and insufficiency of fuel. Two methods were used to determine the induction length of two-phase detonation wave through the pressure history. Ignition delay time was found to be longer than deflagration-to-detonation transition (DDT) time, and the sum of the two would change little as cycle frequency increased. So they could be the most important factors controlling two-phase PDE frequency. Filling process and blowdown process were also analyzed.

  6. Causes of SiO2 Content Exceeding Standard in the Boiler Water after the Typhoon%台风过后锅炉炉水二氧化硅超标原因分析

    Institute of Scientific and Technical Information of China (English)

    杨晨; 梁昌英

    2014-01-01

    Analyze causes of the SiO2 content exceeding standard in the water of high pressure steam boiler . Take following measures:increasing analysis of steam drum water and the steam , increasing continous blowdown of steam drum water ,improving the water desalination preparation process ,and increasing analysis of total silicon content ,active silicon content and colloid silicon content in the water which entering into the water desalination device .Then the water quality returns to normal .%介绍台风过后,高压蒸汽锅炉炉水二氧化硅超标的原因。采取增加对汽包炉水和蒸汽的分析次数、增大汽包炉水的连续排污,改进对脱盐水制备过程,增加对进脱盐水装置水的全硅含量、活性硅含量和胶体硅含量的分析等措施,使锅炉水质恢复正常。

  7. An emergency water injection system (EWIS) for future CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Andre L.F. [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil). E-mail: momarques@uol.com.br; Todreas, Neil E.; Driscoll, Michael J. [Massachusetts Inst.of Tech., Cambridge, MA (United States). Nuclear Engineering Dept.

    2000-07-01

    This paper deals with the investigation of the feasibility and effectiveness of water injection into the annulus between the calandria tubes and the pressure tubes of CANDU reactors. The purpose is to provide an efficient decay heat removal process that avoids permanent deformation of pressure tubes severe accident conditions, such as loss of coolant accident (LOCA). The water injection may present the benefit of cost reduction and better actuation of other related safety systems. The experimental work was conducted at the Massachusetts Institute of Technology (MIT), in a setup that simulated, as close as possible, a CANDU bundle annular configuration, with heat fluxes on the order of 90 kW/m{sup 2}: the inner cylinder simulates the pressure tube and the outer tube represents the calandria tube. The experimental matrix had three dimensions: power level, annulus water level and boundary conditions. The results achieved overall heat transfer coefficients (U), which are comparable to those required (for nominal accident progression) to avoid pressure tube permanent deformation, considering current CANDU reactor data. Nonetheless, future work should be carried out to investigate the fluid dynamics such as blowdown behavior, in the peak bundle, and the system lay-out inside the containment to provide fast water injection. (author)

  8. The noncondensable gas effects on loss-of-coolant accident steam condensation loads in boiling water reactor pressure suppression pool

    Energy Technology Data Exchange (ETDEWEB)

    Kukita, Y.; Namatame, K.; Shiba, M.; Takeshita, I.

    1983-11-01

    The noncondensable gas effects on the loss-ofcoolant-accident-induced steam condensation loads in the boiling water reactor pressure suppression pool have been investigated with regard to experimental data obtained from a large-scale multivent test program. Previous studies have noted that the presence of the noncondensable gas (air), which initially fills the containment drywell space, stabilizes the direct-contact condensation in the pressure suppression pool and hampers onset of the chugging phenomenon, which induces most significant steam condensation load onto the pool boundary. This was found to be true for the tests with relatively small-break diameters, where the maximum steam mass fluxes in the vent pipe were lower than the upper threshold value for the onset of chugging. However, in the tests with the maximum vent steam mass fluxes moderately higher than the chugging upper threshold value, early depletion of the noncondensable gas tended to result in significant stabilization of steam condensation accompanied by an excursion of temperature of pool water surrounding the vent pipe outlets, which led to a delayed onset of chugging. Due to this combined influence of the noncondensable gas and nonuniform pool temperature, and due to dependence of magnitude of chugging load on the vent steam mass flux, the peak magnitude of the steam condensation load appearing in a blowdown can be very sensitive to the initial and break conditions.

  9. Recirculation pump discharge line break tests at ROSA-III for a boiling water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.; Anoda, Y.; Kumamaru, H.; Nakamura, H.; Shiba, M.; Tasaka, K.

    1985-08-01

    Three loss-of-coolant accident (LOCA) tests were conducted at the Rig of Safety Assessment (ROSA)-III test facility, which simulates boiling water reactor (BWR)/6-251 with a volumetric scaling factor of 1/424. The fundamental features of the recirculation pump discharge line break LOCA and the effects of break areas on the features are investigated. It has been confirmed experimentally that the LOCA phenomena in the discharge line break are analogous to those in the suction line break with the same effective choking flow area, which is a sum of the least choking flow areas along the break flow paths and controls the system pressure responses. In general, the maximum effective choking flow area is (A /SUB j/ + A /SUB p/ ) for discharge line breaks and (A /SUB j/ + A /SUB o/ ) for suction line breaks, where A /SUB j/ , A /SUB p/ , and A /SUB o/ are the flow areas of the jet pump drive nozzles, the main recirculation pump discharge nozzle, and the break, respectively. The similarity between the ROSA-III test and a BWR LOCA has been confirmed in the key phenomena by the analyses using the RELAP5/MOD1 code. An atypical behavior is observed in the fuel rod surface temperature transient in the early phase of blowdown due to the limitation of the ROSA-III initial core power.

  10. LBB in Candu plants

    Energy Technology Data Exchange (ETDEWEB)

    Kozluk, M.J.; Vijay, D.K. [Ontario Hydro Nuclear, Toronto, Ontario (Canada)

    1997-04-01

    Postulated catastrophic rupture of high-energy piping systems is the fundamental criterion used for the safety design basis of both light and heavy water nuclear generating stations. Historically, the criterion has been applied by assuming a nonmechanistic instantaneous double-ended guillotine rupture of the largest diameter pipes inside of containment. Nonmechanistic, meaning that the assumption of an instantaneous guillotine rupture has not been based on stresses in the pipe, failure mechanisms, toughness of the piping material, nor the dynamics of the ruptured pipe ends as they separate. This postulated instantaneous double-ended guillotine rupture of a pipe was a convenient simplifying assumption that resulted in a conservative accident scenario. This conservative accident scenario has now become entrenched as the design basis accident for: containment design, shutdown system design, emergency fuel cooling systems design, and to establish environmental qualification temperature and pressure conditions. The requirement to address dynamic effects associated with the postulated pipe rupture subsequently evolved. The dynamic effects include: potential missiles, pipe whipping, blowdown jets, and thermal-hydraulic transients. Recent advances in fracture mechanics research have demonstrated that certain pipes under specific conditions cannot crack in ways that result in an instantaneous guillotine rupture. Canadian utilities are now using mechanistic fracture mechanics and leak-before-break assessments on a case-by-case basis, in limited applications, to support licensing cases which seek exemption from the need to consider the various dynamic effects associated with postulated instantaneous catastrophic rupture of high-energy piping systems inside and outside of containment.

  11. Review on Recent Advances in Pulse Detonation Engines

    Directory of Open Access Journals (Sweden)

    K. M. Pandey

    2016-01-01

    Full Text Available Pulse detonation engines (PDEs are new exciting propulsion technologies for future propulsion applications. The operating cycles of PDE consist of fuel-air mixture, combustion, blowdown, and purging. The combustion process in pulse detonation engine is the most important phenomenon as it produces reliable and repeatable detonation waves. The detonation wave initiation in detonation tube in practical system is a combination of multistage combustion phenomena. Detonation combustion causes rapid burning of fuel-air mixture, which is a thousand times faster than deflagration mode of combustion process. PDE utilizes repetitive detonation wave to produce propulsion thrust. In the present paper, detailed review of various experimental studies and computational analysis addressing the detonation mode of combustion in pulse detonation engines are discussed. The effect of different parameters on the improvement of propulsion performance of pulse detonation engine has been presented in detail in this research paper. It is observed that the design of detonation wave flow path in detonation tube, ejectors at exit section of detonation tube, and operating parameters such as Mach numbers are mainly responsible for improving the propulsion performance of PDE. In the present review work, further scope of research in this area has also been suggested.

  12. Simulation of noncondensable gases in SAGD steam chambers

    Energy Technology Data Exchange (ETDEWEB)

    Gittins, Simon; Gupta, Subodh; Zaman, Maliha [Cenovus Energy (Canada)

    2011-07-01

    Cenovus Energy has been successfully using the steam assisted gravity drainage (SAGD) process at various sites. As these and other wells mature, a greater understanding of non-condensable gasses is required to help to optimize other factors such as methane co-injection and the steam ramp-down and blow-down phases. It is very important to understand fully how non-condensable gasses operate in SAGD chambers in order to lower energy intensity, costs, and the environmental impact while increasing the yield from the reserves. Cenovus Energy also plans on reducing pressure in SAGD and solvent-aided processes in future projects by applying their acquired knowledge of non-condensable gasses. The paper shows results from recent simulations that improve understanding of this subject. Simulation has shown that if there are significant flow restrictions in SAGD injection wells, that would cause the steam to flow at a higher pressure axially along the steam chamber as opposed to axially along the liner and out. This accounts for the production of solution gas.

  13. A simple and rational numerical method of two-phase flow with volume-junction model. 1. Verification calculation in saturated condition

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Motoaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    A new numerical method to achieve a rigorous numerical calculation of each phase using a simple explicit method with volume-junction model is proposed. For this purpose, difference equations for numerical use are carefully derived so as to preserve the physical meaning of the basic equations. Specifically, momentum equations for the flow in the volume are newly derived to keep strict conservation of energy within the volume. To prove the validity of the numerical method and of previously proposed basic equations, including the original phase change equations, which were rigorously derived, some numerical calculations were made for each phase independently to examine the correctness of calculated results. The numerical calculation is advanced by simple integration of an explicitly obtained solution of difference equations without any special treatment. Calculated results of density and specific internal energy of each phase for saturated two-phase blowdown behavior are consistent for two different solution scheme as described below. Further, no accumulation of error in mass or energy was found. These results prove the consistency among basic equations, including phase change equations, and the correctness of numerical calculation method. The two different solution schemes used were: (1) solutions of pressure and void fraction in saturated condition were obtained by using mass conservation equation of each phase simultaneously, and (2) fluid properties were calculated directly from mass and energy conservation equation of each phase. (author)

  14. Evaporative processes for desalination of produced water; Processos evaporativos para dessalinizacao de agua produzida a fins de reuso

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Vivian T.; Dezotti, Marcia W. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Quimica; Schuhli, Juliana B.; Gomes, Marcia T.; Pereira Junior, Oswaldo A. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    During the productive life of an oil well, it gets the moment when a big quantity of produced water comes together with the oil. It can achieve 99% in the end of its economical life. The thermal desalination of the formation water is one of the most common technologies for achieving its reuse. This way, it was constructed one 'Robert' evaporator. The tests used different sodium chloride concentrations from 2,000 mg/L to 80,000 mg/L simulating concentrations found in the produced water from PETROBRAS wells. The tests were conducted in three different vacuum pressures. It was observed, increasing the vacuum applied to the system, results in reduction of solution boiling point. The salt concentrations of the brine blowdown were influenced by the sodium chloride concentration at the feed flow, by the vacuum applied to the system and, consequently, by the solution boiling point and flow rates. The produced distillate water presented sodium chloride concentration lower than 2 mg/L, indicating that this system can produce water to reuse in irrigation. (author)

  15. A modelling study of the multiphase leakage flow from pressurised CO2 pipeline.

    Science.gov (United States)

    Zhou, Xuejin; Li, Kang; Tu, Ran; Yi, Jianxin; Xie, Qiyuan; Jiang, Xi

    2016-04-01

    The accidental leakage is one of the main risks during the pipeline transportation of high pressure CO2. The decompression process of high pressure CO2 involves complex phase transition and large variations of the pressure and temperature fields. A mathematical method based on the homogeneous equilibrium mixture assumption is presented for simulating the leakage flow through a nozzle in a pressurised CO2 pipeline. The decompression process is represented by two sub-models: the flow in the pipe is represented by the blowdown model, while the leakage flow through the nozzle is calculated with the capillary tube assumption. In the simulation, two kinds of real gas equations of state were employed in this model instead of the ideal gas equation of state. Moreover, results of the flow through the nozzle and measurement data obtained from laboratory experiments of pressurised CO2 pipeline leakage were compared for the purpose of validation. The thermodynamic processes of the fluid both in the pipeline and the nozzle were described and analysed.

  16. Dynamic loads caused by pressure blasts, steam explosions, and earth quakes; Dynamische Belastungen durch Druckstoesse, Dampfexplosionen und Erdbeben

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, H.H. [SDK Ingenieurunternehmen GmbH, Basel (Switzerland)

    1998-11-01

    The paper deals with description of structures and the relevant dynamic loads. As to the structures, gas, fluid, or solid structures are to be considered. They determine the characteristic vibrational behaviour of the structures in the interconnected system. The excitation type determines the component that will be induced to change characteristic vibrational behaviour of the structure, depending on the load increasing time and the period of excitation. Three examples are given to illustrate the processes. (Water tank subject to quasi-seismic conditions; pipeline affected by blow-down; shut-off valve for a pipe). (orig./CB) [Deutsch] In diesem Beitrag soll auf die Erfassung der Strukturen und die Erfassung der dynamischen Belastungen eingegangen werden. Zur Erfassung der Strukturen sind `Gas-, Fluid- und Festkoerper-Strukturen` zu beachten. Sie bestimmen das Eigenschwingverhalten im Verbund. Die Erregung bestimmt nun, welcher Bereich aus dem Eigen-Schwingverhalten der Struktur ueber die Lastanstiegs-Zeit und die Zeitdauer der Erregung anregbar ist. Drei Beispiele sollen die Aufgabenstellung erlaeutern (Wasserbehaelter unter erdbebenaehnlichen Bedingungen; Rohrleitung unter `Blow-down-Belastung`; Absperrklappe fuer eine Rohrleitung). (orig./MM)

  17. Assessment study of RELAP5/MOD2 Cycle 36. 04 based on pressurizer safety and relief valve tests

    Energy Technology Data Exchange (ETDEWEB)

    Stubbe, E.J.; Vanhoenacker, L.

    1990-07-01

    This report presents a code assessment study based on full size relief and assisted safety valve (called SEBIM) tests performed on the CUMULUS valve test rig operated by Electricite de France (EdF). The increased awareness that the pressuriser safety and relief valves are not reliable under water blowdown conditions, has led to the design, testing and installation of so called assisted safety valves of which the SEBIM (TM) valves are an example. These valves, used in tandem, are gradually replacing the safety and relief valves on pressurisers in some European PWR's. Before installation at the plant, the Belgian safety authorities requested a thorough full scale testing of these valves on a test rig (CUMULUS) equipped with sufficient diagnostics to measure the characteristics of the valve. The Belgian architect-engineering firm TRACTEBEL was called upon the specify, order and test these valves for installation at the DOEL 1 and DOEL 2 power plants. These tests do provide sufficient data of high quality to justify an assessment study of the code RELAP-5 MOD-2 CYCLE 36 in the ICAP framework which is the subject of this report.

  18. ITER Port Interspace Pressure Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, Juan J [ORNL; Van Hove, Walter A [ORNL

    2016-01-01

    The ITER Vacuum Vessel (VV) is equipped with 54 access ports. Each of these ports has an opening in the bioshield that communicates with a dedicated port cell. During Tokamak operation, the bioshield opening must be closed with a concrete plug to shield the radiation coming from the plasma. This port plug separates the port cell into a Port Interspace (between VV closure lid and Port Plug) on the inner side and the Port Cell on the outer side. This paper presents calculations of pressures and temperatures in the ITER (Ref. 1) Port Interspace after a double-ended guillotine break (DEGB) of a pipe of the Tokamak Cooling Water System (TCWS) with high temperature water. It is assumed that this DEGB occurs during the worst possible conditions, which are during water baking operation, with water at a temperature of 523 K (250 C) and at a pressure of 4.4 MPa. These conditions are more severe than during normal Tokamak operation, with the water at 398 K (125 C) and 2 MPa. Two computer codes are employed in these calculations: RELAP5-3D Version 4.2.1 (Ref. 2) to calculate the blowdown releases from the pipe break, and MELCOR, Version 1.8.6 (Ref. 3) to calculate the pressures and temperatures in the Port Interspace. A sensitivity study has been performed to optimize some flow areas.

  19. Periodical shedding of cloud cavitation from a single hydrofoil in high-speed cryogenic channel flow

    Institute of Scientific and Technical Information of China (English)

    Yutaka ITO; Koichi SETO; Takao NAGASAKI

    2009-01-01

    In order to explain criteria for periodical shedding of the cloud cavitation, flow patterns of cavitation around a piano-convex hydrofoil were observed using a cryogenic cavitation tunnel of a blowdown type. Two hydrofoils of similarity of 20 and 60 mm in chord length with two test sections of 20 and 60 mm in width were prepared. Working fluids were water at ambient temperature, hot water and liquid nitrogen. The parameter range was varied between 0.3 and 1.4 for cavitation number, 9 and 17 m/sec for inlet flow velocity, and -8° and 8° for the flow in-cidence angle, respectively. At incidence angle 8°, that is, the convex surface being suction surface, periodical shedding of the whole cloud cavitation was observed on the convex surface under the specific condition with cavitation number and inlet flow velocity, respectively, 0.5, 9 m/sec for liquid nitrogen at 192℃ and 1.4, 11 m/sec for water at 88℃, whereas under the supercavitation condition, it was not observable. Periodical shedding of cloud cavitation occurs only in the case that there are both the adverse pressure gradient and the slow flow region on the hydrofoil.

  20. A FORTRAN program for calculating three dimensional, inviscid and rotational flows with shock waves in axial compressor blade rows: User's manual

    Science.gov (United States)

    Thompkins, W. T., Jr.

    1982-01-01

    A FORTRAN-IV computer program was developed for the calculation of the inviscid transonic/supersonic flow field in a fully three dimensional blade passage of an axial compressor rotor or stator. Rotors may have dampers (part span shrouds). MacCormack's explicit time marching method is used to solve the unsteady Euler equations on a finite difference mesh. This technique captures shocks and smears them over several grid points. Input quantities are blade row geometry, operating conditions and thermodynamic quanities. Output quantities are three velocity components, density and internal energy at each mesh point. Other flow quanities are calculated from these variables. A short graphics package is included with the code, and may be used to display the finite difference grid, blade geometry and static pressure contour plots on blade to blade calculation surfaces or blade suction and pressure surfaces. The flow in a low aspect ratio transonic compressor was analyzed and compared with high response total pressure probe measurements and gas fluorescence static density measurements made in the MIT blowdown wind tunnel. These comparisons show that the computed flow fields accurately model the measured shock wave locations and overall aerodynamic performance.

  1. 气体钻井设备在新疆煤层气项目中的应用%Application of gas drilling equipment in Xinjiang coalbed methane project

    Institute of Scientific and Technical Information of China (English)

    孙立伟

    2011-01-01

    Most coalbed methane reservoirs are featured by low pressure, low permeability and low saturation, etc. Circulation loss is a frequent problem encountered in the process of coal seam drilling. On the other hand, conventional stimulation and blowdown recovery techniques are hard to work. Application of gas drilling equipment in Xinjiang coalbed methane project for aerated underbalanced drilling and methane displacement with nitrogen has shown very good effect in coping with circulation loss problem and improving coalbed methane recovery.%大多数煤层气藏具有低压、低渗、低饱和度等特点,这使得一方面在煤层钻井过程中容易出现井漏问题,另一方面使得常规增产改造和降压开发技术难于奏效.通过对气体钻井设备在新疆煤层气项目中充气欠平衡钻井和注氮驱替甲烷施工的分析,表明气体钻井设备对于解决地层漏失和提高煤层气的采收率具有很好的现场应用效果.

  2. Fluid-structure interaction in BWR suppression pool systems. Final report. [PELE-IC code

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1979-09-01

    The discharge of safety relief valves or a severe loss-of-coolant event in a boiling-water-cooled reactor steam supply system triggers a complex pressure suppression system that is based upon sub-surface steam condensation in large pools of water. The physical problems fall into two categories. The first is referred to as vent clearing and describes the process of expelling non-condensables from the system prior to steam flow. The second category covers a variety of phenomena related to the transient overexpansion of a condensable volume and the subsequent inertially-driven volume decrease. The dynamic loading of either event, depending upon fluid-structural design parameters, can be of concern in safety analysis. This report describes the development of a method for calculating the loads and the structural response for both types of problems. The method is embedded in a computer code, called PELE-IC, that couples a two-dimensional, incompressible eulerian fluid algorithm to a finite element shell algorithm. The fluid physics is based upon the SOLA algorithm, which provideds a trial velocity field using the Navier-Stokes equations that is subsequently corrected iteratively so that incompressibility, fluid-structure interface compatibility, and boundary conditions are satisfied. These fluid and fluid-structure algorithms have been extensively verified through calculations of known solutions from the classical literature, and by comparison to air and steam blowdown experiments.

  3. Experiment data report for Semiscale Mod-1 tests S-05-2A and S-05-2B (alternate ECC injection tests)

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Jr., M. L.; Collins, B. L.; Sackett, K. E.

    1977-04-01

    Recorded test data are presented for Tests S-05-2A and S-05-2B of the Semiscale Mod-1 alternate ECC injection test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Tests S-05-2A and S-05-2B were conducted from initial conditions of 2263 psia and 543/sup 0/F and 2272 psia and 542/sup 0/F, respectively, to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the cold leg broken loop piping. During the tests, cooling water was injected into the intact loop pump suction and broken loop cold leg to simulate emergency core coolant injection in a PWR with flow rates based on system volume scaling. For Test S-05-2A the intact loop pump speed was held constant throughout the test at the initial blowdown value. During Test S-05-2B the pump speed was reduced and stopped according to a predetermined coastdown schedule.

  4. CFD and FEM modeling of PPOOLEX experiments

    Energy Technology Data Exchange (ETDEWEB)

    Paettikangas, T.; Niemi, J.; Timperi, A. (VTT Technical Research Centre of Finland (Finland))

    2011-01-15

    Large-break LOCA experiment performed with the PPOOLEX experimental facility is analysed with CFD calculations. Simulation of the first 100 seconds of the experiment is performed by using the Euler-Euler two-phase model of FLUENT 6.3. In wall condensation, the condensing water forms a film layer on the wall surface, which is modelled by mass transfer from the gas phase to the liquid water phase in the near-wall grid cell. The direct-contact condensation in the wetwell is modelled with simple correlations. The wall condensation and direct-contact condensation models are implemented with user-defined functions in FLUENT. Fluid-Structure Interaction (FSI) calculations of the PPOOLEX experiments and of a realistic BWR containment are also presented. Two-way coupled FSI calculations of the experiments have been numerically unstable with explicit coupling. A linear perturbation method is therefore used for preventing the numerical instability. The method is first validated against numerical data and against the PPOOLEX experiments. Preliminary FSI calculations are then performed for a realistic BWR containment by modeling a sector of the containment and one blowdown pipe. For the BWR containment, one- and two-way coupled calculations as well as calculations with LPM are carried out. (Author)

  5. Simulation, experimentation and analyzation of vacuum pressure swing adsorption process for CO2 capture from dry flue gas%真空变压吸附捕集烟道气中二氧化碳的模拟、实验及分析

    Institute of Scientific and Technical Information of China (English)

    阎海宇; 付强; 周言; 李冬冬; 张东辉

    2016-01-01

    This paper firstly conducted the experiments of CO2 capture from flue gas by vacuum pressure swing adsorption (VPSA) based on the two-bed experimental set-up using industrial silica as adsorbent. The mathematical model of VPSA process was built in gPROMS and its validity was well verified by comparing the results of simulation with experiment. The concentration of CO2 can be enriched to 74% from 15% with recovery of 91.52% by the two-bed VPSA process. Based on the model, the relationship of product concentration, recovery, energy consumption of CO2 with feed flowrate, adsorption time and blowdown pressure was investigated. The influence of bed pressure and feed flowrate on compressor energy consumption was also studied. Results showed that the concentration of CO2 can be enriched significantly by increasing feed flowrate, extending adsorption time and decreasing counter-blowdown pressure, but all of them were companied with reduction in recovery and the former two led to a higher energy consumption. The higher in adsorption pressure and larger in feed flowrate, the more energy will the compressor consumed.%采用工业硅胶作为吸附剂,利用两塔变压吸附装置进行了烟道气变压吸附碳捕集实验。利用gPROMS软件建立两塔变压吸附模型对实验过程进行模拟,对比了实验和模拟的结果,验证了模型的准确性。通过两塔变压吸附可将15%的CO2富集到74%,收率为91.52%。在模型基础上考察了变压吸附碳捕集过程中进料量、吸附时间、顺放压力与二氧化碳收率、纯度和能耗的关系,定性分析了吸附塔压力和进料量对压缩机能耗的影响。结果表明:增大进料量、延长吸附时间、降低顺放压力,可以有效提高产品气中CO2浓度,但同时也导致收率的下降,前两者还会造成单位能耗的增加;吸附压力越高,进料流量越大,压缩机能耗越大。

  6. Validation of effective momentum and heat flux models for stratification and mixing in a water pool

    Energy Technology Data Exchange (ETDEWEB)

    Hua Li; Villanueva, W.; Kudinov, P. [Royal Institute of Technology (KTH), Div. of Nuclear Power Safety, Stockholm (Sweden)

    2013-06-15

    The pressure suppression pool is the most important feature of the pressure suppression system in a Boiling Water Reactor (BWR) that acts primarily as a passive heat sink during a loss of coolant accident (LOCA) or when the reactor is isolated from the main heat sink. The steam injection into the pool through the blowdown pipes can lead to short term dynamic phenomena and long term thermal transient in the pool. The development of thermal stratification or mixing in the pool is a transient phenomenon that can influence the pool's pressure suppression capacity. Different condensation regimes depending on the pool's bulk temperature and steam flow rates determine the onset of thermal stratification or erosion of stratified layers. Previously, we have proposed to model the effect of steam injection on the mixing and stratification with the Effective Heat Source (EHS) and the Effective Momentum Source (EMS) models. The EHS model is used to provide thermal effect of steam injection on the pool, preserving heat and mass balance. The EMS model is used to simulate momentum induced by steam injection in different flow regimes. The EMS model is based on the combination of (i) synthetic jet theory, which predicts effective momentum if amplitude and frequency of flow oscillations in the pipe are given, and (ii) model proposed by Aya and Nariai for prediction of the amplitude and frequency of oscillations at a given pool temperature and steam mass flux. The complete EHS/EMS models only require the steam mass flux, initial pool bulk temperature, and design-specific parameters, to predict thermal stratification and mixing in a pressure suppression pool. In this work we use EHS/EMS models implemented in containment thermal hydraulic code GOTHIC. The PPOOLEX experiments (Lappeenranta University of Technology, Finland) are utilized to (a) quantify errors due to GOTHIC's physical models and numerical schemes, (b) propose necessary improvements in GOTHIC sub-grid scale

  7. Influence of windthrows and tree species on forest soil plant biomass and carbon stocks

    Science.gov (United States)

    Veselinovic, B.; Hager, H.

    2012-04-01

    The role of forests has generally been recognized in climate change mitigation and adaptation strategies and policies (e.g. Kyoto Protocol within articles 3.3 and 3.4, RES-E Directive of EU, Country Biomass Action Plans etc.). Application of mitigation actions, to decrease of CO2-emissions and, as the increase of carbon(C)-stocks and appropriate GHG-accounting has been hampered due to a lack of reliable data and good statistical models for the factors influencing C-sequestration in and its release from these systems (e.g. natural and human induced disturbances). Highest uncertainties are still present for estimation of soil C-stocks, which is at the same time the second biggest C-reservoir on earth. Spruce monocultures have been a widely used management practice in central Europe during the past century. Such stands are in lower altitudes (e.g. submontane to lower montane elevation zone) and on heavy soils unstable and prone to disturbances, especially on blowdown. As the windthrow-areas act as CO2-source, we hypothesize that conversion to natural beech and oak forests will provide sustainable wood supply and higher stability of stands against blowdown, which simultaneously provides the long-term belowground C-sequestration. This work focuses on influence of Norway spruce, Common beech and Oak stands on belowground C-dynamics (mineral soil, humus and belowground biomass) taking into consideration the increased impact of windthrows on spruce monocultures as a result of climate change. For this purpose the 300-700m altitude and pseudogley (planosols/temporally logged) soils were chosen in order to evaluate long-term impacts of the observed tree species on belowground C-dynamics and human induced disturbances on secondary spruce stands. Using the false chronosequence approach, the C-pools have been estimated for different compartments and age classes. The sampling of forest floor and surface vegetation was done using 30x30 (homogenous plots) and 50x50cm (inhomogeneous

  8. Development Testing of 1-Newton ADN-Based Rocket Engines

    Science.gov (United States)

    Anflo, K.; Gronland, T.-A.; Bergman, G.; Nedar, R.; Thormählen, P.

    2004-10-01

    With the objective to reduce operational hazards and improve specific and density impulse as compared with hydrazine, the Research and Development (R&D) of a new monopropellant for space applications based on AmmoniumDiNitramide (ADN), was first proposed in 1997. This pioneering work has been described in previous papers1,2,3,4 . From the discussion above, it is clear that cost savings as well as risk reduction are the main drivers to develop a new generation of reduced hazard propellants. However, this alone is not enough to convince a spacecraft builder to choose a new technology. Cost, risk and schedule reduction are good incentives, but a spacecraft supplier will ask for evidence that this new propulsion system meets a number of requirements within the following areas: This paper describes the ongoing effort to develop a storable liquid monopropellant blend, based on AND, and its specific rocket engines. After building and testing more than 20 experimental rocket engines, the first Engineering Model (EM-1) has now accumulated more than 1 hour of firing-time. The results from test firings have validated the design. Specific impulse, combustion stability, blow-down capability and short pulse capability are amongst the requirements that have been demonstrated. The LMP-103x propellant candidate has been stored for more than 1 year and initial material compatibility screening and testing has started. 1. Performance &life 2. Impact on spacecraft design &operation 3. Flight heritage Hereafter, the essential requirements for some of these areas are outlined. These issues are discussed in detail in a previous paper1 . The use of "Commercial Of The Shelf" (COTS) propulsion system components as much as possible is essential to minimize the overall cost, risk and schedule. This leads to the conclusion that the Technology Readiness Level (TRL) 5 has been reached for the thruster and propellant. Furthermore, that the concept of ADN-based propulsion is feasible.

  9. Pulse Distributing Manifold; Pulse Distributing Manifold

    Energy Technology Data Exchange (ETDEWEB)

    Schutting, Eberhard [Technische Univ. Graz (Austria); Sams, Theodor [AVL List GmbH, Graz (Austria); Glensvig, Michael [Forschungsgesellschaft mbH, Graz (AT). Kompetenzzentrum ' ' Das virtuelle Fahrzeug' ' (VIF)

    2011-07-01

    The Pulse Distributing Manifold is a new charge exchange method for turbocharged diesel engines with exhaust gas recirculation (EGR). The method is characterized in that the EGR mass flow is not diverted from the exhaust gas mass flow continuously, but over time broken into sub-streams. The temporal interruption is achieved by two phase-shifted outlet valves which are connected via separate manifolds only with the turbocharger or only with the EGR path. The time points of valve opening are chosen such that the turbocharger and the aftertreatment process of exhaust gas is perfused by high-energy exhaust gas of the blowdown phase while cooler and less energy-rich exhaust gas of the exhaust period is used for the exhaust gas recirculation. This increases the enthalpy for the turbocharger and the temperature for the exhaust gas treatment, while the cooling efficiency at the EGR cooler is reduced. The elimination of the continuous EGR valve has a positive effect on pumping losses. The principle functioning and the potential of this system could be demonstrated by means of a concept study using one-dimensional simulations. Without disadvantages in fuel consumption for the considered commercial vehicle engine, a reduction the EGR cooler performance by 15 % and an increase in exhaust temperature of 35 K could be achieved. The presented charge exchange method was developed, evaluated and patented within the scope of the research program 'K2-mobility' of the project partners AVL (Mainz, Federal Republic of Germany) and University of Technology Graz (Austria). The research project 'K2-Mobility' is supported by the competence center 'The virtual vehicle' Forschungsgesellschaft mbH (Graz, Austria).

  10. Mountain pine beetles and emerging issues in the management of woodland caribou in Westcentral British Columbia

    Directory of Open Access Journals (Sweden)

    Deborah Cichowski

    2005-05-01

    Full Text Available The Tweedsmuir—Entiako caribou (Rangifer tarandus caribou herd summers in mountainous terrain in the North Tweedsmuir Park area and winters mainly in low elevation forests in the Entiako area of Westcentral British Columbia. During winter, caribou select mature lodgepole pine (Pinus contorta forests on poor sites and forage primarily by cratering through snow to obtain terrestrial lichens. These forests are subject to frequent large-scale natural disturbance by fire and forest insects. Fire suppression has been effective in reducing large-scale fires in the Entiako area for the last 40—50 years, resulting in a landscape consisting primarily of older lodgepole pine forests, which are susceptible to mountain pine beetle (Dendroctonus ponderosae attack. In 1994, mountain pine beetles were detected in northern Tweedsmuir Park and adjacent managed forests. To date, mountain pine beetles have attacked several hundred thousand hectares of caribou summer and winter range in the vicinity of Tweedsmuir Park, and Entiako Park and Protected Area. Because an attack of this scale is unprecedented on woodland caribou ranges, there is no information available on the effects of mountain pine beetles on caribou movements, habitat use or terrestrial forage lichen abundance. Implications of the mountain pine beetle epidemic to the Tweedsmuir—Entiako woodland caribou population include effects on terrestrial lichen abundance, effects on caribou movement (reduced snow interception, blowdown, and increased forest harvesting outside protected areas for mountain pine beetle salvage. In 2001 we initiated a study to investigate the effects of mountain pine beetles and forest harvesting on terrestrial caribou forage lichens. Preliminary results suggest that the abundance of Cladina spp. has decreased with a corresponding increase in kinnikinnick (Arctostaphylos uva-ursi and other herbaceous plants. Additional studies are required to determine caribou movement and

  11. Steam separator modeling for various nuclear reactor transients

    Energy Technology Data Exchange (ETDEWEB)

    Paik, C Y; Mullen, G; Knoess, C; Griffith, P

    1987-06-01

    In a pressurized water reactor steam generator, a moisture separator is used to separate steam and liquid and to insure that essentially dry steam is supplied to the turbine. During a steam line break or combined steam line break plus tube rupture, a number of phenomena can occur in the separator which have no counterparts during steady-state operation. How the separator will perform under these circumstances is important for two reasons, it affects the carry-over of radioactive iodine and the water inventory in the secondary side. This study has as its goal the development of a simple separator model which can be applied to a variety of steam generator for off-design conditions. Experiments were performed using air and water on three different types of centrifugal separators: a cyclone as a generic separator, a Combustion Engineering type stationary swirl vane separator, and a Westinghouse type separator. The cyclone separator system has three stages of separation: first the cyclone, then a gravity separator, and finally a chevron plate separator. The other systems have only a centrifugal separator to isolate the effect of the primary separator. Experiments were also done in MIT blowdown rig, with and without a separator, using steam and water. The separators appear to perform well at flow rates well above the design values as long as the downcomer water level is not high. High downcomer water level rather than high flow rates appear to be the primary cause of degraded performance. Appreciable carry-over from the separator section of a steam generator occurs when the drain lines from three stages of separation are unable to carry off the liquid flow. Failure scenarios of the separator for extreme range of conditions from the quasi-steady state transient to the fast transients are presented. A general model structure and simple separator models are provided.

  12. Maritza East 1 presentation

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, M.; Haillet, J.-M.; Casier, F. [ALSTOM Power (Italy). Enviornmental Control Systems

    2007-07-01

    The paper describes the project to develop a 670 MW gross and 600 MW net lignite-fired power plant, the AES-3C Maritza East 1, to be realised adjacent to the site of the existing Maritza East 1 power plant. The site is 40 kilometres south-east of Stara Zagora and 250 km south-east of Sofia, Bulgaria. The project will be more efficient and have lower emissions of sulphur dioxide per MW of electricity generated than the existing Maritza East 1 facility. The facility will have low NOx emissions, an electrostatic precipitator to control the emissions of particular matter and a flue gas desulfurization system to control emissions of sulphur dioxide. The AES 3-C Maritza East 1 plant meets all emissions criteria as defined by the Bulgarian Government, the EU and all other relevant authorities unlike the plants at Maritza East 2 and 1 which will either have to retrofit abatement technology in the next few years or face the prospect of limited hours operation and eventual closure after 2008. The new facility will have zero discharge of waste water. Condenser cooling will be provided by a natural draught cooling tower fed in part by process waters. This recycling of water for the cooling tower will significantly reduce the amount of water withdrawn from the lake. In addition, cooling tower blowdown and other potential facility discharges will be used within the wet limestone flue gas desulfurization system. ALSTOM has paid careful attention to all the different aspects involved: minimisation of environmental impact for both air, water and soil by applying state of the art technologies in all the different areas of the project and, at the same time, delivering an economically profitable installation. 2 ills.

  13. Relative vegetation profiles in a Neotropical forest: comparison of lidar instrumentation and field-based measurements

    Science.gov (United States)

    Sullivan, F. B.; Palace, M. W.; Ducey, M.; Czarnecki, C.; Zanin Shimbo, J.; Mota e Silva, J.

    2012-12-01

    Tropical forests are considered to be some of the most structurally complex forests in the world. Understanding vegetation height structure in these forests can aid in understanding the spatial temporal components of disturbance, from blowdowns to gap dynamics. Vegetation profiles can be used to better estimate carbon storage and flux across the landscape. Using light detection and ranging (lidar) data collected at La Selva, Costa Rica from four instruments (three airborne, one terrestrial) at four times since 2005, and field data collected in January 2012, we generated relative vegetation profiles for twenty plots in La Selva. Relative vegetation profiles were derived from lidar data by accounting for obscured plant material through a log transformation of the cumulative proportion of observations (percent canopy closure). Profiles were derived from field data using two different sets of allometric equations describing crown shape and tree height. We conducted a cluster analysis on similarity matrices developed in R (version 2.14.1) using three different metrics (sum of squares, Kullback-Leibler divergence, Kolmogorov-Smirnov D statistic) and identified general similarity between lidar profiles. Results were consistent across each of the three similarity metrics. Three distinct clusters were found, with profiles from three airborne lidar instruments, two profiles from a terrestrial lidar instrument, and profiles derived from field data forming the clusters. Our results indicate that although estimating lidar relative vegetation profiles from field data was not possible, terrestrial lidar relative vegetation profiles are generally similar to airborne relative vegetation profiles. Given the rapidity and repeatability of terrestrial lidar measurements, these results show promise for terrestrial lidar instruments to collect plot-specific data on forest structure and vertical distribution of plant material. Furthermore, identifying relationships between terrestrial and

  14. Advanced design and economic considerations for commercial geothermal power plants at Heber and Niland, California. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1977-10-01

    Two separate studies, involving advanced design and economic considerations for commercial geothermal power plants using liquid-dominated hydrothermal resources, are presented. In the first study, the effects on design, capital cost, and bus bar electric energy production cost caused by an anticipated decline in available geothermal fluid temperature over the lifetime of power plants are described. A two-stage, flashed-steam energy conversion process was used for the conceptual design of the power plants, which operate from the moderate-temperature, low-salinity reservoir at Heber, California. Plants with net capacities of 50, 100, and 200 MWe (net) were investigated. The results show that it is important to include provision for geothermal fluid temperature decline in the design of power plants to prevent loss of electric energy production capability and to reduce bus bar electric energy costs. In the second study, the technical, economic, and environmental effects of adding regeneration to a 50 MWe (net) power plant employing the multistage-flash/binary process are described. Regeneration is potentially attractive because it recovers waste heat from the turbine exhaust and uses it in the power cycle. However, the pressure drop caused by the introduction of the regenerator decreases the turbine expansion and thus decreases system performance. An innovative approach was taken in the design of the regenerator, which minimized the expected performance degradation of the turbine. The result was that the performance, capital cost, and bus bar electric energy production cost are nearly the same for the processes with and without regeneration. On the other hand, the addition of regeneration has the environmental benefits of substantially reducing heat rejection to the atmosphere and cooling tower makeup and blowdown water requirements. It also increases the temperature of the brine returned to the field for reinjection.

  15. Forward osmosis applied to evaporative cooling make-up water

    Energy Technology Data Exchange (ETDEWEB)

    Nicoll, Peter; Thompson, Neil; Gray, Victoria [Modern Water plc, Guildford (United Kingdom)

    2012-11-15

    Modern Water is in the process of developing a number of forward osmosis based technologies, ranging from desalination to power generation. This paper outlines the progress made to date on the development and commercial deployment of a forward osmosis based process for the production of evaporative cooling tower make-up water from impaired water sources, including seawater. Evaporative cooling requires significant amounts of good quality water to replace the water lost by evaporation, drift and blowdown. This water can be provided by conventional desalination processes or by the use of tertiary treated sewage effluent. The conventional processes are well documented and understood in terms of operation and power consumption. A new process has been successfully developed and demonstrated that provides make-up water directly, using a core platform 'forward osmosis' technology. This new technology shows significant promise in allowing various raw water sources, such as seawater, to be used directly in the forward osmosis step, thus releasing the use of scarce and valuable high grade water for other more important uses. The paper presents theoretical and operational results for the process, where it is shown that the process can produce make-up water at a fraction of the operational expenditure when compared to conventional processes, in particular regarding power consumption, which in some cases may be as low as 15 % compared to competing processes. Chemical additives to the cooling water (osmotic agent) are retained within the process, thus reducing their overall consumption. Furthermore the chemistry of the cooling water does not support the growth of Legionella pneumophila. Corrosion results are also reported. (orig.)

  16. An improved gate valve for critical applications in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kalsi, M.S.; Alvarez, P.D.; Wang, J.K.; Somagyi, D. [Kalsi Engineering, Inc., Sugar Land, TX (United States)] [and others

    1996-12-01

    U.S. Nuclear Regulatory Commission Generic Letters 89-10 for motor-operated valves (MOVs) and 95-07 for all power-operated valves document in detail the problems related to the performance of the safety-related valves in nuclear power plants. The problems relate to lack of reliable operation under design basis conditions including higher than anticipated stem thrust, unpredictable valve behavior, damage to the valve internals under blowdown/high flow conditions, significant degradation of performance when cycled under AP and flow, thermal binding, and pressure locking. This paper describes an improved motor-operated flexible wedge gate valve design, the GE Sentinel Valve, which is the outcome of a comprehensive and systematic development effort undertaken to resolve the issues identified in the NRC Generic Letters 89-10 and 95-07. The new design provides a reliable, long-term, low maintenance cost solution to the nuclear power industry. One of the key features incorporated in the disc permits the disc flexibility to be varied independently of the disc thickness (pressure boundary) dictated by the ASME Section III Pressure Vessel & Piping Code stress criteria. This feature allows the desired flexibility to be incorporated in the disc, thus eliminating thermal binding problems. A matrix of analyses was performed using finite element and computational fluid dynamics approaches to optimize design for stresses, flexibility, leak-tightness, fluid flow, and thermal effects. The design of the entire product line was based upon a consistent set of analyses and design rules which permit scaling to different valve sizes and pressure classes within the product line. The valve meets all of the ASME Section III Code design criteria and the N-Stamp requirements. The performance of the valve was validated by performing extensive separate effects and plant in-situ tests. This paper summarizes the key design features, analyses, and test results.

  17. Experiments of ECCS strainer blockage and debris settling in suppression pools

    Energy Technology Data Exchange (ETDEWEB)

    Hecker, G.E.; Johnson, A.B.; Murthy, P.; Padmanabhan

    1996-03-01

    If a rupture occurs in a nuclear power station pipe that leads to or from the reactor pressure vessel, the resultant Loss of Coolant Accident (LOCA) would initiate a chain of events involving complex flow phenomena. In a Boiling Water Reactor (BWR), the steam or liquid pipe break pressurizes the dry well, forcing the inert containment gases and steam through downcomers into the suppression pool, thoroughly mixing any particulates and pipe insulation debris carried with the gas flow to the pool. As the steam flow decreases, its unsteady condensation at the end of the downcomers (Condensation Oscillation and Chugging) produces continued water motion in the suppression pool and downcomers. During the blowdown event, high pressure and then low pressure pumps automatically start injecting water from the suppression pool into the reactor to keep its temperature under control. Proper functioning of this Emergency Core Cooling System (ECCS) is critical for the first 30 minutes or so, before operators have time to consider and align alternative sources of cooling water. A major concern for proper operation of the ECCS is the effect of fragmented insulation and plant particulates on the head loss at pump suction strainers. Sufficient loss could exceed the NPSH margin, causing cavitation with a resultant loss of pump capacity and longevity. The bead loss increases with the mass of debris accumulated on the pump strainers, which in turn is dependent on the debris concentration versus time in the suppression pool. This paper describes two sets of experiments that quantified the strainer head loss. One set of experiments considered the mixing and settling of fibrous insulation debris and fine iron oxide particles in the suppression pool during and after chugging. These tests used a reduced scale facility which duplicated the kinetic energy per unit water volume to define the concentration of the actual materials in the pool versus time.

  18. 对《工业锅炉热工性能试验规程》中过热蒸汽锅炉正平衡效率计算的改进建议%Improvement Suggestions on the Calculation of the Superheated Steam Boiler Direct Efifciency in “Thermal Performance Test Code for Industrial Boiler”

    Institute of Scientific and Technical Information of China (English)

    周振华; 成波; 戴恩贤

    2016-01-01

    通过对GB/T 10180—2003《工业锅炉热工性能试验规程》中过热蒸汽锅炉正平衡效率计算公式的热力学分析,原公式在计算输出热量时未扣除取样锅水从饱和蒸汽到过热蒸汽所需热量,导致计算效率高于实际效率。以某台过热蒸汽锅炉的能效定型测试为例,计算表明使用原公式计算会使计算效率比实际效率偏大约0.48%。经修正后的计算公式可提高能效测试的准确性。%Through thermodynamics analysis of the super heater boiler direct efficiency formula in GB/T 10180: 2003 “thermal performance test code for industrial boiler”, it is found the heat from saturated steam to super heater steam for continuous blowdown is never deducted in the former output heat quantity calculating formula. This will lead to the calculation efifciency higher than the actual. Taking an energy efifciency test for a superheated steam boiler as an example, calculation shows that the calculation efifciency is 0.48% larger than actual efifciency by using the former formula. The accuracy of energy efifciency test can be improved by the revised formula.

  19. Biphase turbine bottoming cycle for a diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.; Hays, L.

    1977-02-15

    Application of a two-phase turbine system to waste heat recovery was examined. Bottoming cycle efficiencies ranging from 15 to 30% were calculated for a 720/sup 0/F diesel exhaust temperature. A single stage demonstration unit, designed for non-toxic fluids (water and DowTherm A) and for atmospheric seals and bearings, had a cycle efficiency of 23%. The net output power was 276 hp at 8,100 rpm, increasing the total shaft power from 1,800 hp for the diesel alone, to 2,076 hp for the combined system. A four stage organic turbine, for the same application, had a rotational speed of 14,700 rpm while a four stage steam turbine had 26,000 rpm. Fabrication drawings were prepared for the turbine and nozzle. The major improvement leading to higher cycle efficiency and lower turbine rpm was found to be the use of a liquid component with lower sensible heat. A reduction in capital cost was found to result from the use of a contact heat exchanger instead of tube-fin construction. The cost for a contact heat exchanger was only $35-52/kWe compared to $98/kWe for a tube-fin heat exchanger. Design drawings and materials list were prepared. A program resulting in the demonstration of a two-phase bottoming system was planned and the required cost estimated. The program would result in a feasibility test of the nozzle and turbine at the end of the first year, a laboratory performance test of the bottoming system by the end of the second year and a field demonstration test and laboratory endurance test of the bottoming system during the third year. The blowdown test rig for the first year's program and test turbine were designed.

  20. Tritium distribution modeling in a Light Water New Production Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckle, J.W.

    1989-05-01

    The tritium distribution and tritium release pathways in a new light water production reactor were examined. A computer model was developed to track the tritium as it makes its way through the various plant systems and ends up either as a release to the atmosphere, the cooling tower blowdown or to the solid waste system. The model was designed to predict the integrated yearly tritium releases and provide estimated airborne tritium concentrations in various locations within the plant. WNP-1 was used as a representative model for a Light Water New Production Reactor (LWNPR). The Tritium Distribution Model solves for the time dependent tritium concentration in a system of nodes. These nodes are connected to one another via a set of internodal flow paths and to various sources and sinks. For example, plant systems such as the primary system are the nodes, piping and leaks are the internodal flow paths, make-up water is a source, and release to the atmosphere is a sink. The expected water mass of each node; the flow rates between nodes, sources, and sinks; and tritium source rates are provided as input. The code will solve for the time dependent tritium concentration in each node and the amount of tritium ''released'' to the sinks. Preliminary calculations have been performed using WNP-1 plant specific information obtained primarily from the WNP-1 FSAR. Further work is currently in progress to refine the model and provide a more realistic set of input values which will better represent an operating LWNPR. 1 ref., 1 fig., 1 tab.

  1. Flue gas injection control of silica in cooling towers.

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Patrick Vane; Anderson, Howard L., Jr.; Altman, Susan Jeanne

    2011-06-01

    Injection of CO{sub 2}-laden flue gas can decrease the potential for silica and calcite scale formation in cooling tower blowdown by lowering solution pH to decrease equilibrium calcite solubility and kinetic rates of silica polymerization. Flue gas injection might best inhibit scale formation in power plant cooling towers that use impaired makeup waters - for example, groundwaters that contain relatively high levels of calcium, alkalinity, and silica. Groundwaters brought to the surface for cooling will degas CO{sub 2} and increase their pH by 1-2 units, possibly precipitating calcite in the process. Recarbonation with flue gas can lower the pHs of these fluids back to roughly their initial pH. Flue gas carbonation probably cannot lower pHs to much below pH 6 because the pHs of impaired waters, once outgassed at the surface, are likely to be relatively alkaline. Silica polymerization to form scale occurs most rapidly at pH {approx} 8.3 at 25 C; polymerization is slower at higher and lower pH. pH 7 fluids containing {approx}220 ppm SiO{sub 2} require > 180 hours equilibration to begin forming scale whereas at pH 8.3 scale formation is complete within 36 hours. Flue gas injection that lowers pHs to {approx} 7 should allow substantially higher concentration factors. Periodic cycling to lower recoveries - hence lower silica concentrations - might be required though. Higher concentration factors enabled by flue gas injection should decrease concentrate volumes and disposal costs by roughly half.

  2. Mission Analysis, Operations, and Navigation Toolkit Environment (Monte) Version 040

    Science.gov (United States)

    Sunseri, Richard F.; Wu, Hsi-Cheng; Evans, Scott E.; Evans, James R.; Drain, Theodore R.; Guevara, Michelle M.

    2012-01-01

    Monte is a software set designed for use in mission design and spacecraft navigation operations. The system can process measurement data, design optimal trajectories and maneuvers, and do orbit determination, all in one application. For the first time, a single software set can be used for mission design and navigation operations. This eliminates problems due to different models and fidelities used in legacy mission design and navigation software. The unique features of Monte 040 include a blowdown thruster model for GRAIL (Gravity Recovery and Interior Laboratory) with associated pressure models, as well as an updated, optimalsearch capability (COSMIC) that facilitated mission design for ARTEMIS. Existing legacy software lacked the capabilities necessary for these two missions. There is also a mean orbital element propagator and an osculating to mean element converter that allows long-term orbital stability analysis for the first time in compiled code. The optimized trajectory search tool COSMIC allows users to place constraints and controls on their searches without any restrictions. Constraints may be user-defined and depend on trajectory information either forward or backwards in time. In addition, a long-term orbit stability analysis tool (morbiter) existed previously as a set of scripts on top of Monte. Monte is becoming the primary tool for navigation operations, a core competency at JPL. The mission design capabilities in Monte are becoming mature enough for use in project proposals as well as post-phase A mission design. Monte has three distinct advantages over existing software. First, it is being developed in a modern paradigm: object- oriented C++ and Python. Second, the software has been developed as a toolkit, which allows users to customize their own applications and allows the development team to implement requirements quickly, efficiently, and with minimal bugs. Finally, the software is managed in accordance with the CMMI (Capability Maturity Model

  3. Experiment data report for LOFT nonnuclear test L1-3

    Energy Technology Data Exchange (ETDEWEB)

    Millar, G. M.

    1977-04-01

    Test L1-3 was the third in a series of five nonnuclear isothermal blowdown tests conducted by the Loss of Fluid Test (LOFT) Program. For this test the LOFT Facility was configured to simulate a loss-of-coolant accident in a large pressurized water reactor resulting from a 200 percent double-ended shear break in a cold leg of the primary coolant system. A hydraulic core simulator assembly was installed in place of the nuclear core. The initial conditions in the primary coolant system intact loop were: temperature at 540/sup 0/F, pressure at 2256 psig, and loop flow at 2.34 x 10/sup 6/ lbm/hr. During system depressurization, emergency core cooling water was specified to be injected into the lower plenum of the reactor vessel using an accumulator, a low-pressure injection system pump, and a high-pressure injection system pump to provide data on the effects of emergency core cooling on the system thermal-hydraulic response. Injection into the lower plenum was initiated from the high- and low-pressure injection systems. Injection from the accumulator, however, was not initiated because a valve was inadvertently left closed. The experiment, therefore, was not completely successful in that one of the objectives outlined in the experiment operating specification for this test was not accomplished. Test L1-3 was repeated at Test L1-3A to meet the experimental requirements. Despite these difficulties, Test L1-3 did provide very valuable data to verify experiment repeatability.

  4. The probability of containment failure by direct containment heating in Zion

    Energy Technology Data Exchange (ETDEWEB)

    Pilch, M.M. [Sandia National Labs., Albuquerque, NM (United States); Yan, H.; Theofanous, T.G. [California Univ., Santa Barbara, CA (United States)

    1994-12-01

    This report is the first step in the resolution of the Direct Containment Heating (DCH) issue for the Zion Nuclear Power Plant using the Risk Oriented Accident Analysis Methodology (ROAAM). This report includes the definition of a probabilistic framework that decomposes the DCH problem into three probability density functions that reflect the most uncertain initial conditions (UO{sub 2} mass, zirconium oxidation fraction, and steel mass). Uncertainties in the initial conditions are significant, but our quantification approach is based on establishing reasonable bounds that are not unnecessarily conservative. To this end, we also make use of the ROAAM ideas of enveloping scenarios and ``splintering.`` Two causal relations (CRs) are used in this framework: CR1 is a model that calculates the peak pressure in the containment as a function of the initial conditions, and CR2 is a model that returns the frequency of containment failure as a function of pressure within the containment. Uncertainty in CR1 is accounted for by the use of two independently developed phenomenological models, the Convection Limited Containment Heating (CLCH) model and the Two-Cell Equilibrium (TCE) model, and by probabilistically distributing the key parameter in both, which is the ratio of the melt entrainment time to the system blowdown time constant. The two phenomenological models have been compared with an extensive database including recent integral simulations at two different physical scales. The containment load distributions do not intersect the containment strength (fragility) curve in any significant way, resulting in containment failure probabilities less than 10{sup {minus}3} for all scenarios considered. Sensitivity analyses did not show any areas of large sensitivity.

  5. Containment loads due to direct containment heating and associated hydrogen behavior: Analysis and calculations with the CONTAIN code

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D C; Bergeron, K D; Carroll, D E; Gasser, R D; Tills, J L; Washington, K E

    1987-05-01

    One of the most important unresolved issues governing risk in many nuclear power plants involves the phenomenon called direct containment heating (DCH), in which it is postulated that molten corium ejected under high pressure from the reactor vessel is dispersed into the containment atmosphere, thereby causing sufficient heating and pressurization to threaten containment integrity. Models for the calculation of potential DCH loads have been developed and incorporated into the CONTAIN code for severe accident analysis. Using CONTAIN, DCH scenarios in PWR plants having three different representative containment types have been analyzed: Surry (subatmospheric large dry containment), Sequoyah (ice condenser containment), and Bellefonte (atmospheric large dry containment). A large number of parameter variation and phenomenological uncertainty studies were performed. Response of DCH loads to these variations was found to be quite complex; often the results differ substantially from what has been previously assumed concerning DCH. Containment compartmentalization offers the potential of greatly mitigating DCH loads relative to what might be calculated using single-cell representations of containments, but the actual degree of mitigation to be expected is sensitive to many uncertainties. Dominant uncertainties include hydrogen combustion phenomena in the extreme environments produced by DCH scenarios, and factors which affect the rate of transport of DCH energy to the upper containment. In addition, DCH loads can be aggravated by rapid blowdown of the primary system, co-dispersal of moderate quantities of water with the debris, and quenching of de-entrained debris in water; these factors act by increasing steam flows which, in turn, accelerates energy transport. It may be noted that containment-threatening loads were calculated for a substantial portion of the scenarios treated for some of the plants considered.

  6. Propulsion engineering study for small-scale Mars missions

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, J.

    1995-09-12

    Rocket propulsion options for small-scale Mars missions are presented and compared, particularly for the terminal landing maneuver and for sample return. Mars landing has a low propulsive {Delta}v requirement on a {approximately}1-minute time scale, but at a high acceleration. High thrust/weight liquid rocket technologies, or advanced pulse-capable solids, developed during the past decade for missile defense, are therefore more appropriate for small Mars landers than are conventional space propulsion technologies. The advanced liquid systems are characterize by compact lightweight thrusters having high chamber pressures and short lifetimes. Blowdown or regulated pressure-fed operation can satisfy the Mars landing requirement, but hardware mass can be reduced by using pumps. Aggressive terminal landing propulsion designs can enable post-landing hop maneuvers for some surface mobility. The Mars sample return mission requires a small high performance launcher having either solid motors or miniature pump-fed engines. Terminal propulsion for 100 kg Mars landers is within the realm of flight-proven thruster designs, but custom tankage is desirable. Landers on a 10 kg scale also are feasible, using technology that has been demonstrated but not previously flown in space. The number of sources and the selection of components are extremely limited on this smallest scale, so some customized hardware is required. A key characteristic of kilogram-scale propulsion is that gas jets are much lighter than liquid thrusters for reaction control. The mass and volume of tanks for inert gas can be eliminated by systems which generate gas as needed from a liquid or a solid, but these have virtually no space flight history. Mars return propulsion is a major engineering challenge; earth launch is the only previously-solved propulsion problem requiring similar or greater performance.

  7. ChemAND - a system health monitor for plant chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W.; Mitchel, G.R.; Tosello, G.; Balakrishnan, P.V.; McKay, G.; Thompson, M. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Dundar, Y.; Bergeron, M.; Laporte, R. [Hydro-Quebec, Groupe Chimie, Centrale Nucleaire Gentilly-2, Gentilly, Quebec (Canada)

    2001-03-01

    Effective management of plant systems throughout their lifetime requires much more than data acquisition and display - it requires that the plant's system health be continually monitored and managed. AECL has developed a System Health Monitor called ChemAND for CANDU plant chemistry. ChemAND, a Chemistry ANalysis and Diagnostic system, monitors key chemistry parameters in the heat transport system, moderator-cover gas, annulus gas, and the steam cycle during full-power operation. These parameters can be used as inputs to models that calculate the effect of current plant operating conditions on the present and future health of the system. Chemistry data from each of the systems are extracted on a regular basis from the plant's Historical Data Server and are sorted according to function, e.g., indicators for condenser in-leakage, air in-leakage, heavy water leakage into the annulus gas, fuel failure, etc. Each parameter is conveniently displayed and is trended along with its alarm limits. ChemAND currently includes two analytical models developed for the balance-of-plant. The first model, ChemSolv, calculates crevice chemistry conditions in the steam generator (SG) from either the SG blowdown chemistry conditions or from a simulated condenser leak. This information can be used by plant staff to evaluate the susceptibility of the SG tubes to crevice corrosion. ChemSolv also calculates chemistry conditions throughout the steam-cycle system as determined by the transport of volatile species such as ammonia, hydrazine, morpholine, and oxygen. The second model, SLUDGE, calculates the deposit loading and distribution in the SG as a function of time, based on concentrations of corrosion product in the final feedwater for both normal and start-up conditions. Operations personnel can use this information to predict where to inspect and when to clean. (author)

  8. Breckinridge Project, initial effort

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-01-01

    The project cogeneration plant supplies electric power, process steam and treated boiler feedwater for use by the project plants. The plant consists of multiple turbine generators and steam generators connected to a common main steam header. The major plant systems which are required to produce steam, electrical power and treated feedwater are discussed individually. The systems are: steam, steam generator, steam generator fuel, condensate and feedwater deaeration, condensate and blowdown collection, cooling water, boiler feedwater treatment, coal handling, ash handling (fly ash and bottom ash), electrical, and control system. The plant description is based on the Phase Zero design basis established for Plant 31 in July of 1980 and the steam/condensate balance as presented on Drawing 31-E-B-1. Updating of steam requirements as more refined process information becomes available has generated some changes in the steam balance. Boiler operation with these updated requirements is reflected on Drawing 31-D-B-1A. The major impact of updating has been that less 600 psig steam generated within the process units requires more extraction steam from the turbine generators to close the 600 psig steam balance. Since the 900 psig steam generation from the boilers was fixed at 1,200,000 lb/hr, the additional extraction steam required to close the 600 psig steam balance decreased the quantity of electrical power available from the turbine generators. In the next phase of engineering work, the production of 600 psig steam will be augmented by increasing convection bank steam generation in the Plant 3 fired heaters by 140,000 to 150,000 lb/hr. This modification will allow full rated power generation from the turbine generators.

  9. An analysis of factors causing the occurrence of off-design thermally induced force effects in the zone of weld joint no. 111-1 in a PGV-1000M steam generator and recommendations on excluding them

    Science.gov (United States)

    Bakirov, M. B.; Levchuk, V. I.; Povarov, V. P.; Gromov, A. F.

    2014-08-01

    Inadmissible operational flaws occurring in the critical zones of heat-transfer and mechanical equipment are commonly revealed in all nuclear power plant units both in Russia and abroad. The number of such flaws will only grow in the future because the majority of nuclear power plants have been in operation for a time that is either close to or even exceeds the assigned service life. In this connection, establishing cause-and-effect relations with regard to accelerated incipience and growth of flaws, working out compensating measures aimed at reducing operational damageability, and setting up monitoring of equipment integrity degradation of during operation are becoming the matters of utmost importance. There is a need to introduce new approaches to comprehensive diagnostics of the technical state of important nuclear power plant equipment, including continuous monitoring of its operational damageability and the extent of its loading in the most critical zones. Starting from 2011, such a monitoring system has successfully been used for the Novovoronezh NPP Unit 5 in the zone of weld joint no. 111-1 of steam generator no. 4. Based on the results from operation of this system in 2011-2013, unsteady thermally induced force effects (periodic thermal shocks and temperature abnormalities) were reveled, which had not been considered in the design, and which have an essential influence on the operational loading of this part. Based on an analysis of cause-and-effect relations pertinent to temperature abnormalities connected with technological operations, a set of measures aimed at reducing the thermally induced force loads exerted on pipeline sections was developed, which includes corrections to the process regulations for safe operation and to the operating manuals (involving changes in the algorithms for manipulating with the stop and control valves in the steam generator blowdown system).

  10. Biological assessments for the low energy demonstration accelerator, 1996 and 1997

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1998-12-31

    The Department of Energy (DOE) plans to build, install, and operate a Low Energy Demonstration Accelerator (LMA) in Technical Area 53 of the Los Alamos National Laboratory (LANL). LEDA will demonstrate the accelerator technology necessary to produce tritium, but is not designed to produce tritium at LANL. USFWS reviewers of the Biological Assessment prepared for LEDA insisted that the main drainage be monitored to measure and document changes to vegetation, soils, wildlife, and habitats due to LEDA effluent discharges. The Biology Team of ESH-20 (LANL`s Ecology Group) has performed these monitoring activities during 1996 and 1997 to document baseline conditions before LEDA released significant effluent discharges. Quarterly monitoring of the outfall which will discharge LEDA blowdown effluent had one exceedance of permitted parameters, a high chlorine discharge that was quickly remedied. Samples from 12 soil pits in the drainage area contained no hydric indicators, such as organic matter in the upper layers, streaking, organic pans, and oxidized rhizospheres. Vegetation transacts in the meadows that LEDA discharges will flow through contained 44 species of herbaceous plants, all upland taxa. Surveys of resident birds, reptiles, and amphibians documented a fauna typical of local dry canyons. No threatened or endangered species inhabit the project area, but increased effluent releases may make the area more attractive to many wildlife species, an endangered raptor, and several other species of concern. Biological best management practices especially designed for LEDA are discussed, including protection of floodplains, erosion control measures, hazards posed by increased usage of the area by deer and elk and revegetation of disturbed areas.

  11. International Space Station (ISS) Gas Logistics Planning in the Post Shuttle Era

    Science.gov (United States)

    Leonard, Daniel J.; Cook, Anthony J.; Lehman, Daniel A.

    2011-01-01

    Over its life the International Space Station (ISS) has received gas (nitrogen, oxygen, and air) from various sources. Nitrogen and oxygen are used in the cabin to maintain total pressure and oxygen partial pressures within the cabin. Plumbed nitrogen is also required to support on-board experiments and medical equipment. Additionally, plumbed oxygen is required to support medical equipment as well as emergency masks and most importantly EVA support. Gas are supplied to ISS with various methods and vehicles. Vehicles like the Progress and ATV deliver nitrogen (both as a pure gas and as air) and oxygen via direct releases into the cabin. An additional source of nitrogen and oxygen is via tanks on the ISS Airlock. The Airlock nitrogen and oxygen tanks can deliver to various users via pressurized systems that run throughout the ISS except for the Russian segment. Metabolic oxygen is mainly supplied via cabin release from the Elektron and Oxygen Generator Assembly (OGA), which are water electrolyzers. As a backup system, oxygen candles (Solid Fuel Oxygen Generators-SFOGs) supply oxygen to the cabin as well. In the past, a major source of nitrogen and oxygen has come from the Shuttle via both direct delivery to the cabin as well as to recharge the ISS Airlock tanks. To replace the Shuttle capability to recharge the ISS Airlock tanks, a new system was developed called Nitrogen/Oxygen Recharge System (NORS). NIORS consists of high pressure (7000 psi) tanks which recharge the ISS Airlock tanks via a blowdown fill for both nitrogen and oxygen. NORS tanks can be brought up on most logistics vehicles such as the HTV, COTS, and ATV. A proper balance must be maintained to insure sufficient gas resources are available on-orbit so that all users have the required gases via the proper delivery method (cabin and/or plumbed).

  12. PPOOLEX experiments on wall condensation

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2009-08-15

    This report summarizes the results of the wall condensation experiments carried out in December 2008 and January 2009 with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a DN200 blowdown pipe to the condensation pool. Altogether five experiments, each consisting of several blows, were carried out. The main purpose of the experiment series was to study wall condensation phenomenon inside the dry well compartment while steam is discharged through it into the condensation pool and to produce comparison data for CFD calculations at VTT. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. For the wall condensation experiments the test facility was equipped with a system for collecting and measuring the amount of condensate from four different wall segments of the dry well compartment. A thermo graphic camera was used in a couple of experiments for filming the outside surface of the dry well wall. The effect of the initial temperature level of the dry well structures and of the steam flow rate for the accumulation of condensate was studied. The initial temperature level of the dry well structures varied from 23 to 99 deg. C. The steam flow rate varied from 90 to 690 g/s and the temperature of incoming steam from 115 to 160 deg. C. During the initial phase of steam discharge the accumulation of condensate was strongly controlled by the temperature level of the dry well structures; the lower the initial temperature level was the more condensate was accumulated. As the dry well structural temperatures increased the condensation process slowed down. Most of the condensate usually accumulated during the first 200 seconds of the discharge. However, the condensation process never completely stopped because a small temperature difference remained between the dry well atmosphere and inner wall

  13. Establishment and assessment of code scaling capability

    Science.gov (United States)

    Lim, Jaehyok

    In this thesis, a method for using RELAP5/MOD3.3 (Patch03) code models is described to establish and assess the code scaling capability and to corroborate the scaling methodology that has been used in the design of the Purdue University Multi-Dimensional Integral Test Assembly for ESBWR applications (PUMA-E) facility. It was sponsored by the United States Nuclear Regulatory Commission (USNRC) under the program "PUMA ESBWR Tests". PUMA-E facility was built for the USNRC to obtain data on the performance of the passive safety systems of the General Electric (GE) Nuclear Energy Economic Simplified Boiling Water Reactor (ESBWR). Similarities between the prototype plant and the scaled-down test facility were investigated for a Gravity-Driven Cooling System (GDCS) Drain Line Break (GDLB). This thesis presents the results of the GDLB test, i.e., the GDLB test with one Isolation Condenser System (ICS) unit disabled. The test is a hypothetical multi-failure small break loss of coolant (SB LOCA) accident scenario in the ESBWR. The test results indicated that the blow-down phase, Automatic Depressurization System (ADS) actuation, and GDCS injection processes occurred as expected. The GDCS as an emergency core cooling system provided adequate supply of water to keep the Reactor Pressure Vessel (RPV) coolant level well above the Top of Active Fuel (TAF) during the entire GDLB transient. The long-term cooling phase, which is governed by the Passive Containment Cooling System (PCCS) condensation, kept the reactor containment system that is composed of Drywell (DW) and Wetwell (WW) below the design pressure of 414 kPa (60 psia). In addition, the ICS continued participating in heat removal during the long-term cooling phase. A general Code Scaling, Applicability, and Uncertainty (CSAU) evaluation approach was discussed in detail relative to safety analyses of Light Water Reactor (LWR). The major components of the CSAU methodology that were highlighted particularly focused on the

  14. Twenty-Five Years of Ecological Recovery of East Fork Poplar Creek: Review of Environmental Problems and Remedial Actions

    Science.gov (United States)

    Loar, James M.; Stewart, Arthur J.; Smith, John G.

    2011-06-01

    In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Department of Energy's Y-12 National Security Complex (Y-12 Complex) in Oak Ridge, Tennessee, USA, allowing discharge of effluents to East Fork Poplar Creek (EFPC). The effluents ranged from large volumes of chlorinated once-through cooling water and cooling tower blow-down to smaller discharges of treated and untreated process wastewaters, which contained a mixture of heavy metals, organics, and nutrients, especially nitrates. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to meet two major objectives: demonstrate that the established effluent limitations were protecting the classified uses of EFPC, and document the ecological effects resulting from implementing a Water Pollution Control Program at the Y-12 Complex. The second objective is the primary focus of the other papers in this special series. This paper provides a history of pollution and the remedial actions that were implemented; describes the geographic setting of the study area; and characterizes the physicochemical attributes of the sampling sites, including changes in stream flow and temperature that occurred during implementation of the BMAP. Most of the actions taken under the Water Pollution Control Program were completed between 1986 and 1998, with as many as four years elapsing between some of the most significant actions. The Water Pollution Control Program included constructing nine new wastewater treatment facilities and implementation of several other pollution-reducing measures, such as a best management practices plan; area-source pollution control management; and various spill-prevention projects. Many of the major actions had readily discernable effects on the chemical and physical conditions of EFPC. As controls on effluents entering the stream were implemented, pollutant concentrations generally declined and, at least initially, the volume of water

  15. ForWarn Forest Disturbance Change Detection System Provides a Weekly Snapshot of US Forest Conditions to Aid Forest Managers

    Science.gov (United States)

    Hargrove, W. W.; Spruce, J.; Kumar, J.; Hoffman, F. M.

    2012-12-01

    The Eastern Forest Environmental Threat Assessment Center and Western Wildland Environmental Assessment Center of the USDA Forest Service have collaborated with NASA Stennis Space Center to develop ForWarn, a forest monitoring tool that uses MODIS satellite imagery to produce weekly snapshots of vegetation conditions across the lower 48 United States. Forest and natural resource managers can use ForWarn to rapidly detect, identify, and respond to unexpected changes in the nation's forests caused by insects, diseases, wildfires, severe weather, or other natural or human-caused events. ForWarn detects most types of forest disturbances, including insects, disease, wildfires, frost and ice damage, tornadoes, hurricanes, blowdowns, harvest, urbanization, and landslides. It also detects drought, flood, and temperature effects, and shows early and delayed seasonal vegetation development. Operating continuously since January 2010, results show ForWarn to be a robust and highly capable tool for detecting changes in forest conditions. To help forest and natural resource managers rapidly detect, identify, and respond to unexpected changes in the nation's forests, ForWarn produces sets of national maps showing potential forest disturbances at 231m resolution every 8 days, and posts the results to the web for examination. ForWarn compares current greenness with the "normal," historically seen greenness that would be expected for healthy vegetation for a specific location and time of the year, and then identifies areas appearing less green than expected to provide a strategic national overview of potential forest disturbances that can be used to direct ground and aircraft efforts. In addition to forests, ForWarn also tracks potential disturbances in rangeland vegetation and agriculural crops. ForWarn is the first national-scale system of its kind based on remote sensing developed specifically for forest disturbances. The ForWarn system had an official unveiling and rollout in

  16. Free-flight measurement technique in the free-piston high-enthalpy shock tunnel.

    Science.gov (United States)

    Tanno, H; Komuro, T; Sato, K; Fujita, K; Laurence, S J

    2014-04-01

    A novel multi-component force-measurement technique has been developed and implemented at the impulse facility JAXA-HIEST, in which the test model is completely unrestrained during the test and thus experiences free-flight conditions for a period on the order of milliseconds. Advantages over conventional free-flight techniques include the complete absence of aerodynamic interference from a model support system and less variation in model position and attitude during the test itself. A miniature on-board data recorder, which was a key technology for this technique, was also developed in order to acquire and store the measured data. The technique was demonstrated in a HIEST wind-tunnel test campaign in which three-component aerodynamic force measurement was performed on a blunted cone of length 316 mm, total mass 19.75 kg, and moment of inertia 0.152 kgm(2). During the test campaign, axial force, normal forces, and pitching moment coefficients were obtained at angles of attack from 14° to 32° under two conditions: H0 = 4 MJ/kg, P0 = 14 MPa; and H0 = 16 MJ/kg, P0 = 16 MPa. For the first, low-enthalpy condition, the test flow was considered a perfect gas; measurements were thus directly compared with those obtained in a conventional blow-down wind tunnel (JAXA-HWT2) to evaluate the accuracy of the technique. The second test condition was a high-enthalpy condition in which 85% of the oxygen molecules were expected to be dissociated; high-temperature real-gas effects were therefore evaluated by comparison with results obtained in perfect-gas conditions. The precision of the present measurements was evaluated through an uncertainty analysis, which showed the aerodynamic coefficients in the HIEST low enthalpy test agreeing well with those of JAXA-HWT2. The pitching-moment coefficient, however, showed significant differences between low- and high-enthalpy tests. These differences are thought to result from high-temperature real-gas effects.

  17. Twenty-Plus Years of Environmental Change and Ecological Recovery of East Fork Poplar Creek: Background and Trends in Water Quality

    Energy Technology Data Exchange (ETDEWEB)

    Smith, John G [ORNL; Stewart, Arthur J [ORNL; Loar, James M [ORNL

    2011-01-01

    In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Department of Energy's Y-12 National Security Complex (Y-12 Complex) in Oak Ridge, Tennessee, USA, allowing discharge of effluents to East Fork Poplar Creek (EFPC). The effluents ranged from large volumes of chlorinated once-through cooling water and cooling tower blow-down to smaller discharges of treated and untreated process wastewaters, which contained a mixture of heavy metals, organics, and nutrients, especially nitrates. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to meet two major objectives: demonstrate that the established effluent limitations were protecting the classified uses of EFPC, and document the ecological effects resulting from implementing a Water Pollution Control Program at the Y-12 Complex. The second objective is the primary focus of the other papers in this special series. This paper provides a history of pollution and the remedial actions that were implemented; describes the geographic setting of the study area; and characterizes the physicochemical attributes of the sampling sites, including changes in stream flow and temperature that occurred during implementation of the BMAP. Most of the actions taken under the Water Pollution Control Program were completed between 1986 and 1998, with as many as four years elapsing between some of the most significant actions. The Water Pollution Control Program included constructing nine new wastewater treatment facilities and implementation of several other pollution-reducing measures, such as a best management practices plan; area-source pollution control management; and various spill-prevention projects. Many of the major actions had readily discernable effects on the chemical and physical conditions of EFPC. As controls on effluents entering the stream were implemented, pollutant concentrations generally declined and, at least initially, the volume of

  18. Twenty-Five Years of Ecological Recovery of East Fork Poplar Creek: Review of Environmental Problems and Remedial Actions

    Energy Technology Data Exchange (ETDEWEB)

    Smith, John G [ORNL; Loar, James M [ORNL; Stewart, Arthur J [ORNL

    2011-01-01

    In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Department of Energy s Y-12 National Security Complex (Y-12 Complex) in Oak Ridge, Tennessee, USA, allowing discharge of effluents to East Fork Poplar Creek (EFPC). The effluents ranged from large volumes of chlorinated oncethrough cooling water and cooling tower blow-down to smaller discharges of treated and untreated process wastewaters, which contained a mixture of heavy metals, organics, and nutrients, especially nitrates. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to meet two major objectives: demonstrate that the established effluent limitations were protecting the classified uses of EFPC, and document the ecological effects resulting from implementing a Water Pollution Control Program at the Y-12 Complex. The second objective is the primary focus of the other papers in this special series. This paper provides a history of pollution and the remedial actions that were implemented; describes the geographic setting of the study area; and characterizes the physicochemical attributes of the sampling sites, including changes in stream flow and temperature that occurred during implementation of the BMAP. Most of the actions taken under the Water Pollution Control Program were completed between 1986 and 1998, with as many as four years elapsing between some of the most significant actions. The Water Pollution Control Program included constructing nine new wastewater treatment facilities and implementation of several other pollution-reducing measures, such as a best management practices plan; area-source pollution control management; and various spill-prevention projects. Many of the major actions had readily discernable effects on the chemical and physical conditions of EFPC. As controls on effluents entering the stream were implemented, pollutant concentrations generally declined and, at least initially, the volume of water

  19. Dispersant trial at ANO-2: Qualification for a short-term trial prior to SG replacement

    Energy Technology Data Exchange (ETDEWEB)

    Fruzzetti, K.; Frattini, P. [Electric Power Research Inst., Palo Alto, CA (United States); Robbins, P. [Entergy Operations, Arkansas Nuclear One, Russellville, AR (United States); Miller, A. [Pedro Point Technology, Inc., Pacifica, CA (United States); Varrin, R.; Kreider, M. [Dominion Engineering Inc., McLean, VA (United States)

    2002-07-01

    Corrosion products in the secondary side of pressurized water reactor (PWR) steam generators (SGs) primarily deposit on the SG tubes. These deposits can inhibit heat transfer, lead to thermal-hydraulic instabilities through blockage of tube supports, and create occluded regions where corrosive species can concentrate along tubes and in tube-to-tube support plate crevices. The performance of the SGs is compromised not only by formation of an insulating scale, but by the removal of tubes from service due to corrosion. Currently, there are two strategies employed by utilities for minimizing deposit formation on steam generator internal surfaces. The first is to minimize the source term, i.e., reduce the amount of corrosion products in the feedwater. Two methods are commonly used to accomplish this goal: chemistry optimization and plant modifications. The first method uses alternate amines to control the at-temperature pH (pH{sub T}) in specific locations of the secondary system, thereby minimizing the corrosion of balance of plant (BOP) metals. The second method requires removal of metals from the secondary system that are a significant source of corrosion products (e.g., replace 90/10 Cu/Ni condenser tubes with titanium). The second strategy for lowering deposit loads utilizes chemical or mechanical means to remove existing deposits from the SGs (e.g., chemical cleaning or sludge lancing). Many utilities have opted for a combination of these two strategies. A third potential strategy for minimizing deposition of corrosion products on SG internal surfaces is to use online dispersant addition to help prevent the corrosion products from adhering to the steam generator surfaces. By inhibiting the deposition of the corrosion products, the dispersant can facilitate more effective removal from the SGs via blowdown. This type of strategy has been employed at fossil boilers for many decades. However, due to the use of inorganic (sulfur and other impurities) polymerization

  20. Application of Pulsed Electrical Fields for Advanced Cooling and Water Recovery in Coal-Fired Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Young Cho; Alexander Fridman

    2009-04-02

    The overall objective of the present work was to develop technologies to reduce freshwater consumption in a cooling tower of coal-based power plant so that one could significantly reduce the need of make-up water. The specific goal was to develop a scale prevention technology based an integrated system of physical water treatment (PWT) and a novel filtration method so that one could reduce the need for the water blowdown, which accounts approximately 30% of water loss in a cooling tower. The present study investigated if a pulsed spark discharge in water could be used to remove deposits from the filter membrane. The test setup included a circulating water loop and a pulsed power system. The present experiments used artificially hardened water with hardness of 1,000 mg/L of CaCO{sub 3} made from a mixture of calcium chloride (CaCl{sub 2}) and sodium carbonate (Na{sub 2}CO{sub 3}) in order to produce calcium carbonate deposits on the filter membrane. Spark discharge in water was found to produce strong shockwaves in water, and the efficiency of the spark discharge in cleaning filter surface was evaluated by measuring the pressure drop across the filter over time. Results showed that the pressure drop could be reduced to the value corresponding to the initial clean state and after that the filter could be maintained at the initial state almost indefinitely, confirming the validity of the present concept of pulsed spark discharge in water to clean dirty filter. The present study also investigated the effect of a plasma-assisted self-cleaning filter on the performance of physical water treatment (PWT) solenoid coil for the mitigation of mineral fouling in a concentric counterflow heat exchanger. The self-cleaning filter utilized shockwaves produced by pulse-spark discharges in water to continuously remove scale deposits from the surface of the filter, thus keeping the pressure drop across the filter at a relatively low value. Artificial hard water was used in the

  1. 基于VSP2的放热反应失控紧急泄放特性%Characteristics of emergency venting on exothermic reaction runaway based on VSP2

    Institute of Scientific and Technical Information of China (English)

    喻健良; 闫兴清; 孟庭宇; 谢传欣

    2013-01-01

    基于VSP2绝热量热仪,通过增加泄放物收集罐、快速响应气动阀及泄放孔板,开展了放热反应失控泄放实验,详细探讨了输入热功率、初始填充率、泄放压力、泄放直径以及反应物发泡性对泄放能力及泄放物质量的影响.结果表明:二相流泄放能力随输入热功率增大而降低,随初始填充率增大先增大后减小,随泄放压力增大先快速降低后缓慢增加,随泄放直径增大而增大.泄放物质量随输入热功率、初始填充率、泄放压力和泄放直径的增大而增大.发泡性材料能显著降低泄放装置的泄放能力,但能增大泄放物质量.%Through the addition of effluent container,rapid response pneumatic valve and orifice based on VSP2 (Vent Sizing Package 2),the blowdown tests of exothermic reaction runaway were conducted.The impact of heating power,initial fill rate,venting pressure,venting diameter and the reactant foaming property on the venting capacity and the effluent mass were investigated.The results indicate that the venting capacity decreases with the increase of heating power,and increases then falls with the rise of fill rate.In addition,the vent capacity decreases rapidly then increases slowly with the increase of venting pressure.Larger venting diameter leads to larger venting capacity.The effluent mass increases with the rise of heating power,fill rate,venting pressure and venting diameter.Foamy reactants can greatly decrease the venting capacity whereas increase the effluent mass.

  2. 天然气长输管道火炬放空扩散规律研究%Study on Diffusion Law of Gas During Long Distance Gas Pipeline Venting

    Institute of Scientific and Technical Information of China (English)

    梁俊奕

    2016-01-01

    天然气的放空扩散非常危险,研究天然气长输管道火炬放空扩散的规律,可以为其安全放空提供指导依据。PHAST 软件是公认的最权威最准确的后果分析软件,可以用于长输管道的天然气放空扩散计算。采用该软件建立天然气长输管道系统的亚临界流不点火放空的扩散模型,确定天然气在不点火放空过程中可能燃烧的危险区域。以某实际长输管道为例,计算两种工况下天然气扩散规律。结果显示,在放空过程中风速影响天然气的扩散。低风速时,天然气会向上扩散,在高风速时,天然气向水平方向扩散。天然气50%LFL 云团水平距离随风速的增大而增加,云团高度随风速的增加而减小。%Diffusion of gas is very dangerous during flare venting. The research on the diffusion law of gas during long distance gas pipeline flare venting can provide guidance for gas blowdown.PHAST is recognized as the most authoritative and accurate consequence analysis software and can be used to calculate the flare venting. The software is adopted to establish subcritical flow diffusion model of gas during long distance gas pipeline venting. Danger zone of gas ignition can be determined. In this paper, taking a practical long-distance pipeline as an example, diffusion law of natural gas was calculated under the two conditions. The results show that wind speed can affect the gas diffusion.The gas upward diffuses when wind speed is low; the gas horizontally diffuses when wind speed is high.Natural gas 50%LFL cloud horizontal distance increases with the increase of wind speed and cloud height decreases with the increase of wind speed.

  3. Characterization Investigation Study: Volume 3, Radiological survey of surface soils

    Energy Technology Data Exchange (ETDEWEB)

    Solow, A.J.; Phoenix, D.R.

    1987-12-01

    The Feed Materials Production Center was constructed to produce high purity uranium metal for use at various Department of Energy facilities. The waste products from these operations include general uncontaminated scrap and refuse, contaminated and uncontaminated metal scrap, waste oils, low-level radioactive waste, co-contaminated wastes, mixed waste, toxic waste, sludges from water treatment, and fly ash from the steam plant. This material is estimated to total more than 350,000 cubic meters. Other wastes stored in this area include laboratory chemicals and other combustible materials in the burn pit; fine waste stream sediments in the clear well; fly ash and waste oils in the two fly ash areas; lime-alum sludges and boiler plant blowdown in the lime sludge ponds; and nonradioactive sanitary waste, construction rubble, and asbestos in the sanitary landfill. A systematic survey of the surface soils throughout the Waste Storage Area, associated on-site drainages, and the fly ash piles was conducted using a Field Instrument for Detecting Low-Energy Radiation (FIDLER). Uranium is the most prevalent radioactive element in surface soil; U-238 is the principal radionuclide, ranging from 2.2 to 1790 pCi/g in the general Waste Storage Area. The maximum values for the next highest activity concentrations in the same area were 972 pCi/g for Th-230 and 298 pCi/g for U-234. Elevated activity concentrations of Th-230 were found along the K-65 slurry line, the maximum at 3010 pCi/g. U-238 had the highest value of 761 pCi/g in the drainage just south of pit no. 5. The upper fly ash area had the highest radionuclide activity concentrations in the surface soils with the maximum values for U-238 at 8600 pCi/g, U-235 at 2190 pCi/g, U-234 at 11,400 pCi/g, Tc-99 at 594 pCi/g, Ra-226 at 279 pCi/g, and Th-230 at 164 pCi/g.

  4. Numerical simulation of gas-solids two-phase flow field of built-in fourth stage cyclone separation system in FCCU%FCC内置式四旋分离系统内气固两相流场的数值研究

    Institute of Scientific and Technical Information of China (English)

    王锐; 王建军; 赵艳; 金有海

    2014-01-01

    通过数值模拟的方法,采用RSM湍流模型对FCC内置式四旋分离系统内气固两相流场进行了研究。研究表明,四旋灰斗底部存在错流,不利于排料;储料罐顶部平衡管泄气有利于四旋排料,但同时增加了颗粒逃逸的概率,降低分离系统效率;分离系统内颗粒运动轨迹包括灰斗捕集、排气管逃逸及平衡管逃逸,控制颗粒在平衡管逃逸可通过在储料罐内添加锥形挡板结构实现;四旋环形空间顶部与灰斗底部锥段颗粒浓度较高,易对四旋内壁产生磨损;内置式四旋分离系统优点在于不存在催化剂跑损问题。%The Reynolds stress model was used to simulate gas-solids flow field of built-in fourth stage separation cyclone system in FCCU. Cross flow existed at the bottom of the dust hopper in the cyclone separator, which was not favorable for particle discharge. Although blowdown on the top of the dust storage tank could help separator discharge, it also increased the chance of particles escaping from the balance tube, lowering separation efficiency. The movement trajectory of particles in the system included trapped in the dust hopper of the dust storage tank, escaping from the vortex finder and the balance tube. In order to reduce particles escaping from the balance tube, adding a cone baffle in the dust storage tank could be an effective way. Particle concentration was higher at the top of the annular space and the bottom of the dust hopper, causing wall wear out. The built-in fourth stage separation cyclone system had an advantage of resolving catalyst loss.

  5. Short-term pressure and temperature MSLB response analyses for large dry containment of the Maanshan nuclear power station

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Liang-Che, E-mail: lcdai@iner.gov.tw; Chen, Yen-Shu; Yuann, Yng-Ruey

    2014-12-15

    Highlights: • The GOTHIC code is used for the PWR dry containment pressure and temperature analysis. • Boundary conditions are hot standby and 102% power main steam line break accidents. • Containment pressure and temperature responses of GOTHIC are similar with FSAR. • The capability of the developed model to perform licensing calculation is assessed. - Abstract: Units 1 and 2 of the Maanshan nuclear power station are the typical Westinghouse three-loop PWR (pressurized water reactor) with large dry containments. In this study, the containment analysis program GOTHIC is adopted for the dry containment pressure and temperature analysis. Free air space and sump of the PWR dry containment are individually modeled as control volumes. The containment spray system and fan cooler unit are also considered in the GOTHIC model. The blowdown mass and energy data of the main steam line break (hot standby condition and various reactor thermal power levels) are tabulated in the Maanshan Final Safety Analysis Report (FSAR) 6.2 which could be used as the boundary conditions for the containment model. The calculated containment pressure and temperature behaviors of the selected cases are in good agreement with the FSAR results. In this study, hot standby and 102% reactor thermal power main steam line break accidents are selected. The calculated peak containment pressure is 323.50 kPag (46.92 psig) for hot standby MSLB, which is a little higher than the FSAR value of 311.92 kPag (45.24 psig). But it is still below the design value of 413.69 kPag (60 psig). The calculated peak vapor temperature inside the containment is 187.0 °C (368.59 F) for 102% reactor thermal power MSLB, which is lower than the FSAR result of 194.42 °C (381.95 F). The effects of the containment spray system and fan cooler units could be clearly observed in the GOTHIC analysis. The calculated containment pressure and temperature behaviors of the selected cases are in good agreement with the FSAR

  6. Paroxysmal dome explosion during the Merapi 2010 eruption: Processes and facies relationships of associated high-energy pyroclastic density currents

    Science.gov (United States)

    Komorowski, Jean-Christophe; Jenkins, Susanna; Baxter, Peter J.; Picquout, Adrien; Lavigne, Franck; Charbonnier, Sylvain; Gertisser, Ralf; Preece, Katie; Cholik, Noer; Budi-Santoso, Agus; Surono

    2013-07-01

    An 11-minute sequence of laterally-directed explosions and retrogressive collapses on 5 November 2010 at Merapi (Indonesia) destroyed a rapidly-growing dome and generated high-energy pyroclastic density currents (PDCs) spreading over 22 km2 with a runout of 8.4 km while contemporaneous co-genetic valley-confined PDCs reached 15.5 km. This event formed Stage 4 of the multi-stage 2010 eruption, the most intense eruptive episode at Merapi since 1872. The deposits and the widespread devastating impact of associated high-energy PDCs on trees and buildings show striking similarities with those from historical volcanic blasts (Montagne Pelée, Martinique, Bezymianny, Russia, Mount St. Helens, USA, Soufrière Hills, Montserrat). We provide data from stratigraphic and sedimentologic analyses of 62 sections of the first unequivocal blast-like deposits in Merapi's recent history. We used high resolution satellite imagery to map eruptive units and flow direction from the pattern of extensive tree blowdown. The stratigraphy of Stage 4 consists of three depositional units (U0, U1, U2) that we correlate to the second, third and fourth explosions of the seismic record. Both U1 and U2 show a bi-partite layer stratigraphy consisting each of a lower L1 layer and an upper L2 layer. The lower L1 layer is typically very coarse-grained, fines-poor, poorly-sorted and massive, and was deposited by the erosive waxing flow head. The overlying L2 layer is much finer grained, fines-rich, moderately to well-sorted, with laminar to wavy stratification. L2 was deposited from the waning upper part and wake of the PDC. Field observations indicate that PDC height reached ~ 330 m with an internal velocity of ~ 100 m s- 1 within 3 km from the source. The summit's geometry and the terrain morphology formed by a major transversal ridge and a funneling deep canyon strongly focused PDC mass towards a major constriction, thereby limiting the loss of kinetic energy. This favored elevated PDC velocities and

  7. Calculating corrections in F-theory from refined BPS invariants and backreacted geometries

    Energy Technology Data Exchange (ETDEWEB)

    Poretschkin, Maximilian

    2015-07-01

    This thesis presents various corrections to F-theory compactifications which rely on the computation of refined Bogomol'nyi-Prasad-Sommerfield (BPS) invariants and the analysis of backreacted geometries. Detailed information about rigid supersymmetric theories in five dimensions is contained in an index counting refined BPS invariants. These BPS states fall into representations of SU(2){sub L} x SU(2){sub R}, the little group in five dimensions, which has an induced action on the cohomology of the moduli space of stable pairs. In the first part of this thesis, we present the computation of refined BPS state multiplicities associated to M-theory compactifications on local Calabi-Yau manifolds whose base is given by a del Pezzo or half K3 surface. For geometries with a toric realization we use an algorithm which is based on the Weierstrass normal form of the mirror geometry. In addition we use the refined holomorphic anomaly equation and the gap condition at the conifold locus in the moduli space in order to perform the direct integration and to fix the holomorphic ambiguity. In a second approach, we use the refined Goettsche formula and the refined modular anomaly equation that govern the (refined) genus expansion of the free energy of the half K3 surface. By this procedure, we compute the refined BPS invariants of the half K3 from which the results of the remaining del Pezzo surfaces are obtained by flop transitions and blow-downs. These calculations also make use of the high symmetry of the del Pezzo surfaces whose homology lattice contains the root lattice of exceptional Lie algebras. In cases where both approaches are applicable, we successfully check the compatibility of these two methods. In the second part of this thesis, we apply the results obtained from the calculation of the refined invariants of the del Pezzo respectively the half K3 surfaces to count non-perturbative objects in F-theory. The first application is given by BPS states of the E

  8. Performance of natural gas distribution networks during the Kocaeli earthquake - 17 august 1999; Comportement des reseaux de distributions de gaz naturel lors du tremblement de terre de Kocaeli 17 aout 1999

    Energy Technology Data Exchange (ETDEWEB)

    Zarea, M.; Adrien, M. [Gaz de France (GDF), 75 - Paris (France)

    2000-07-01

    The Kocaeli (Izmit) earthquake struck recently, on August 17, 1999, a well developed area of Turkey. This earthquake, of a magnitude 7.4 on the open Richter scale, severely damaged numerous buildings, industrial infrastructure, and made a lot of victims. In this context, most attention is given to issues like: seismology (why and how did it happen, what will happen next, etc.), seismic design and construction (why buildings collapsed and how to avoid this in the future). Some other subjects get less attention, because their direct influence in the overall damage is smaller. The behaviour of 'lifelines', designating all the networks which contribute to 'modern' lifestyle: water, energy, communications, etc., belong to this category. Nevertheless, the performance of lifelines during such strong earthquakes is also important, because they can contribute to minimise its impact. This impact has its usual two aspects: integrity and operability. For instance, the integrity requirement means that failures of the considered lifeline due to the earthquake should not directly affect property and life. The operability requirement means that a given subset of the lifeline remains operational, in order to fulfill vital tasks. We propose here a brief analysis of the performance of two relatively recently commissioned gas distribution systems: IZGAZ in Izmit, close the epicenter, and IDGAS in Istanbul. They have the advantage of representing a large sample of a recent implementation of the PE (polyethylene) technique, which has reached maturity. Both are cases of the Gaz de France 4 bar PE technology transferred to a Turkish operator, who completely managed the crisis. The first part describes the two networks, both their high medium pressure steel network, regulators, and the intermediate PE network, finishing with service lines and boxes. Then, the damage reported by the operational teams and their very important shut-down and blowdown actions are summarised

  9. Implications of Air Ingress Induced by Density-Difference Driven Stratified Flow

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh; Eung Soo Kim; Richard Schultz; David Petti; C. P. Liou

    2008-06-01

    One of the design basis accidents for the Next Generation Nuclear Plant (NGNP), a high temperature gas-cooled reactor, is air ingress subsequent to a pipe break. Following a postulated double-ended guillotine break in the hot duct, and the subsequent depressurization to nearly reactor cavity pressure levels, air present in the reactor cavity will enter the reactor vessel via density-gradient-driven-stratified flow. Because of the significantly higher molecular weight and lower initial temperature of the reactor cavity air-helium mixture, in contrast to the helium in the reactor vessel, the air-helium mixture in the cavity always has a larger density than the helium discharging from the reactor vessel through the break into the reactor cavity. In the later stages of the helium blowdown, the momentum of the helium flow decreases sufficiently for the heavier cavity air-helium mixture to intrude into the reactor vessel lower plenum through the lower portion of the break. Once it has entered, the heavier gas will pool at the bottom of the lower plenum. From there it will move upwards into the core via diffusion and density-gradient effects that stem from heating the air-helium mixture and from the pressure differences between the reactor cavity and the reactor vessel. This scenario (considering density-gradient-driven stratified flow) is considerably different from the heretofore commonly used scenario that attributes movement of air into the reactor vessel and from thence to the core region via diffusion. When density-gradient-driven stratified flow is considered as a contributing phenomena for air ingress into the reactor vessel, the following factors contribute to a much earlier natural circulation-phase in the reactor vessel: (a) density-gradient-driven stratified flow is a much more rapid mechanism (at least one order of magnitude) for moving air into the reactor vessel lower plenum than diffusion, and consequently, (b) the diffusion dominated phase begins with a

  10. Application of Spatial Data Modeling and Geographical Information Systems (GIS) for Identification of Potential Siting Options for Various Electrical Generation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Mays, Gary T [ORNL; Belles, Randy [ORNL; Blevins, Brandon R [ORNL; Hadley, Stanton W [ORNL; Harrison, Thomas J [ORNL; Jochem, Warren C [ORNL; Neish, Bradley S [ORNL; Omitaomu, Olufemi A [ORNL; Rose, Amy N [ORNL

    2012-05-01

    contiguous United States. If a cell meets the requirements of each criterion, the cell is deemed a candidate area for siting a specific power generation form relative to a reference plant for that power type. Some SSEC parameters preclude siting a power plant because of an environmental, regulatory, or land-use constraint. Other SSEC assist in identifying less favorable areas, such as proximity to hazardous operations. All of the selected SSEC tend to recommend against sites. The focus of the ORNL electrical generation source siting study is on identifying candidate areas from which potential sites might be selected, stopping short of performing any detailed site evaluations or comparisons. This approach is designed to quickly screen for and characterize candidate areas. Critical assumptions supporting this work include the supply of cooling water to thermoelectric power generation; a methodology to provide an adequate siting footprint for typical power plant applications; a methodology to estimate thermoelectric plant capacity while accounting for available cooling water; and a methodology to account for future ({approx}2035) siting limitations as population increases and demands on freshwater sources change. OR-SAGE algorithms were built to account for these critical assumptions. Stream flow is the primary thermoelectric plant cooling source evaluated in this study. All cooling was assumed to be provided by a closed-cycle cooling (CCC) system requiring makeup water to account for evaporation and blowdown. Limited evaluations of shoreline cooling and the use of municipal processed water (gray) cooling were performed. Using a representative set of SSEC as input to the OR-SAGE tool and employing the accompanying critical assumptions, independent results for the various power generation sources studied were calculated.

  11. Computational studies of reacting flows with applications to zinc selenide nanoparticle synthesis and methane/hydrogen separation

    Science.gov (United States)

    Koutsona, Maria

    a predictive model describing pressure and concentration dynamics during Pressure Swing Adsorption (PSA) of binary (or pseudo-binary) gas mixtures. The separation of metane-hydrogen mixtures over 5A-zeolite was used as an example. The PSA cycle considered in this study includes the following 5 steps: (1) pressurization with product, (2) high-pressure adsorption, (3) cocurrent depressurization, (4) countercurrent blowdown and (5) countercurrent purge with product at low pressure. The PSA mathematical model describes the following processes gas flow in the bed (as axially dispersed plug flow) and the mass balance of the components of the mixture coupled to adsorption/desorption kinetics. The model results in a system of coupled partial differential equations in the axial bed dimension and time. The Galerkin Finite Element Method was used to discretize the equations in the axial direction of the bed. The resulting system of ordinary differential equations (ODE's) in time is solved by using an Euler full-implicit scheme. The model is being used by Chemical Design, Inc., for the initial design of PSA units.

  12. Management of injected nitrogen into a gas condensate reservoir

    Directory of Open Access Journals (Sweden)

    Hadi Belhaj

    2016-04-01

    Full Text Available This study investigates the means of deferring the breakthrough of injected N2 and alleviating the impact of such on production rates and specifications as well as minimizing the required changes to the gas processing facilities. This aimed at assisting the ongoing efforts to transfer the Cantarell experience to Abu Dhabi, where large amounts of N2 gas will be generated and injected into a large gas condensate reservoir to partially substitute the recycling of lean gas. This will bring forward the opportunity to exploit lean gas by securing base load supplies before the start of reservoir blowdown, compared to the peak shaving approach currently practiced. Managing N2 breakthrough starts by better understanding the pattern at which N2 injection spreads into the gas accumulation. Based on the findings of initial subsurface and plant simulations carried out in 2008, N2 breakthrough in Abu Dhabi might be possibly deferred by segmenting the reservoir into a rich N2 region and lean N2 region. The approach assumes no thief zones will be faced and no channeling of N2 injected between the two regions is taking place. N2 is injected in the north region of the reservoir. The production of that region will be segregated and fed to a gas processing plant of lower NGL (natural gas liquid recovery, which essentially takes longer time to start suffering the deterioration of residue gas (gas mixture resulted after separating NGL quality. The residue gas use can be limited to re-injection where the effect of below specification LHV (Low Heat Value would not be an issue. The rest of the reservoir feeds another gas processing plant of higher NGL recovery level from which an amount of residue gas equivalent to that of the injected N2 will be rerouted to the sales network. This scenario will significantly delay as well as downsize the requirement of a N2 rejection plant. There is technical and certainly economical advantage of deferring the

  13. Online recognition of the multiphase flow regime and study of slug flow in pipeline

    Science.gov (United States)

    Liejin, Guo; Bofeng, Bai; Liang, Zhao; Xin, Wang; Hanyang, Gu

    2009-02-01

    single sensor performance. Among various flow patterns of gas-liquid flow, slug flow occurs frequently in the petroleum, chemical, civil and nuclear industries. In the offshore oil and gas field, the maximum slug length and its statistical distribution are very important for the design of separator and downstream processing facility at steady state operations. However transient conditions may be encountered in the production, such as operational upsets, start-up, shut-down, pigging and blowdown, which are key operational and safety issues related to oil field development. So it is necessary to have an understanding the flow parameters under transient conditions. In this paper, the evolution of slug length along a horizontal pipe in gas-liquid flow is also studied in details and then an experimental study of flowrate transients in slug flow is provided. Also, the special gas-liquid flow phenomena easily encountered in the life span of offshore oil fields, called severe slugging, is studied experimentally and some results are presented.

  14. Low pressure corium dispersion experiments in the DISCO test facility with cold simulant fluids

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, L.; Gargallo, M.; Kirstahler, M.; Schwall, M.; Wachter, E.; Woerner, G.

    2006-08-15

    In a severe accident special pressure relief valves in the primary circuit of German Pressurized Water Reactors (PWR) will transfer a high pressure accident into a low pressure scenario. However, there may be a time window during late in-vessel reflooding scenarios where the pressure is in the order of 1 or 2 MPa at the moment of the reactor vessel rupture. A failure in the bottom head of the reactor pressure vessel, followed by melt expulsion and blowdown of the reactor cooling system, might disperse molten core debris out of the reactor pit, even at such low pressures. The mechanisms of efficient debris-to-gas heat transfer, exothermic metal/oxygen reactions, and hydrogen combustion may cause a rapid increase in pressure and temperature in the reactor containment. Integral experiments are necessary to furnish data for modeling these processes in computer codes, that will be used to apply these result to the reactor case. The acquired knowledge can lead to realize additional safety margins for existing or future plants. The test facility DISCO-C (DIspersion of Simulant COrium - Cold) models the annular reactor cavity and the subcompartments of a large European reactor in a scale 1:18. The fluid dynamics of the dispersion process was studied using model fluids, water or bismuth alloy instead of corium, and nitrogen or helium instead of steam. The effects of different breach sizes and locations, and different failure pressures on the dispersion were studied, specifically by testing central holes, lateral holes, horizontal rips, and complete ripping of the bottom head. 22 experiments were performed in a basic cavity geometry with holes at the bottom of the lower head to study the similarity relations. Variables were the hole diameter, the initial pressure in the RPV and the fluids used. The only flow path out of the reactor pit was the annular gap between the inner wall of the reactor pit and the RPV, and then along the main coolant lines into the subcompartments

  15. An Innovative System for the Efficient and Effective Treatment of Non-Traditional Waters for Reuse in Thermoelectric Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    John Rodgers; James Castle

    2008-08-31

    This study assessed opportunities for improving water quality associated with coal-fired power generation including the use of non-traditional waters for cooling, innovative technology for recovering and reusing water within power plants, novel approaches for the removal of trace inorganic compounds from ash pond effluents, and novel approaches for removing biocides from cooling tower blowdown. This research evaluated specifically designed pilot-scale constructed wetland systems for treatment of targeted constituents in non-traditional waters for reuse in thermoelectric power generation and other purposes. The overall objective of this project was to decrease targeted constituents in non-traditional waters to achieve reuse criteria or discharge limitations established by the National Pollutant Discharge Elimination System (NPDES) and Clean Water Act (CWA). The six original project objectives were completed, and results are presented in this final technical report. These objectives included identification of targeted constituents for treatment in four non-traditional water sources, determination of reuse or discharge criteria for treatment, design of constructed wetland treatment systems for these non-traditional waters, and measurement of treatment of targeted constituents in non-traditional waters, as well as determination of the suitability of the treated non-traditional waters for reuse or discharge to receiving aquatic systems. The four non-traditional waters used to accomplish these objectives were ash basin water, cooling water, flue gas desulfurization (FGD) water, and produced water. The contaminants of concern identified in ash basin waters were arsenic, chromium, copper, mercury, selenium, and zinc. Contaminants of concern in cooling waters included free oxidants (chlorine, bromine, and peroxides), copper, lead, zinc, pH, and total dissolved solids. FGD waters contained contaminants of concern including arsenic, boron, chlorides, selenium, mercury

  16. Isotope exchange kinetics in metal hydrides I : TPLUG model.

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Rich; James, Scott Carlton; Nilson, Robert H.

    2011-05-01

    pronounced deviations at long times. These discrepancies can be overcome by postulating the presence of a surface poison such as carbon monoxide, but this explanation is highly speculative. When the method is applied to D {yields} H exchanges intentionally poisoned by known amounts of CO, the fitting results are noticeably degraded from those for the nominally CO-free system but are still tolerable. When TPLUG is used to simulate a blowdown-type experiment, which is characterized by large and rapid changes in both pressure and temperature, discrepancies are even more apparent. Thus, it can be concluded that the best use of TPLUG is not in simulating realistic exchange scenarios, but in extracting preliminary estimates for the kinetic parameters from experiments in which variations in temperature and pressure are intentionally minimized.

  17. Process of heavy oil thermal recovery wastewater reused as power plant boiler make-up water%稠油热采废水回用电站锅炉补给水工艺

    Institute of Scientific and Technical Information of China (English)

    王璟; 毛进; 赵剑强; 蒲平; 郭维忠; 李亚娟; 刘亚鹏

    2015-01-01

    常规稠油热采废水处理采用除油软化工艺,出水水质较低,仅能用于直流小注汽锅炉补水.由于小注汽锅炉参数低,排污量大,能耗高,造成采油蒸汽成本高.针对该问题,开发了预处理-蒸发-生物处理-膜处理-混床工艺处理稠油热采废水,并通过实验对工艺各子系统运行性能进行研究以提高处理效果,使系统处理出水可用于电站高参数锅炉补给水,达到以热电联产机组取代小注汽锅炉,降低采油蒸汽费用的目的.研究结果表明,采用该工艺对稠油热采废水进行处理,各子系统运行稳定;废水经除硅软化预处理及蒸发后,产水TOC平均约22mg/L;曝气生物滤池产水TOC平均约6mg/L;再经超滤-反渗透处理后产水TOC含量小于0.15mg/L;继续经混床处理,最终出水电导率≤0.15μS/cm、二氧化硅≤10μg/L、TOC≤200μg/L,满足电站高参数锅炉补水水质要求,每吨水直接运行费用为8.05元.%The traditional heavy oil thermal recovery wastewater treatment process is comprised of oil eliminating and softening. The effluent quality is comparably poor which can only be used as make up water for once-through small steam injection boiler. Because the parameter of small steam injection boiler is low,both the boiler blowdown and energy consumption are high. The oil extraction steam cost is raised subsequently. Aimed at the problem,a novel heavy oil thermal recovery wastewater treatment process that comprises of pretreatment,bio-treatment,membrane,and mixed bed technology was developed. Operating performance of individual sub-system was investigated by model experiments to enhance the treatment efficiency and to make it possible to reuse the product water as high parameter power plant unit make up water. As a result,the objective to replace the small steam injection boiler by combined heat and power generation unit to reduce the oil extraction steam fee could be achieved. Results show that the operating

  18. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    ranging from 4 to 21 bar with three different static inventories of non-condensable gas. Condensation and heat transfer rates were evaluated employing several methods, notably from measured temperature gradients in the HTP as well as measured condensate formation rates. A detailed mass and energy accounting was used to assess the various measurement methods and to support simplifying assumptions required for the analysis. Condensation heat fluxes and heat transfer coefficients are calculated and presented as a function of pressure to satisfy the objectives of this investigation. The major conclusions for those tests are summarized below: (1) In the steam blow-down tests, the initial condensation heat transfer process involves the heating-up of the containment heat transfer plate. An inverse heat conduction model was developed to capture the rapid transient transfer characteristics, and the analysis method is applicable to SMR safety analysis. (2) The average condensation heat transfer coefficients for different pressure conditions and non-condensable gas mass fractions were obtained from the integral test facility, through the measurements of the heat conduction rate across the containment heat transfer plate, and from the water condensation rates measurement based on the total energy balance equation. 15 (3) The test results using the measured HTP wall temperatures are considerably lower than popular condensation models would predict mainly due to the side wall conduction effects in the existing MASLWR integral test facility. The data revealed the detailed heat transfer characteristics of the model containment, important to the SMR safety analysis and the validation of associated evaluation model. However this approach, unlike separate effect tests, cannot isolate the condensation heat transfer coefficient over the containment wall, and therefore is not suitable for the assessment of the condensation heat transfer coefficient against system pressure and noncondensable

  19. Institutional impediments to using alternative water sources in thermoelectric power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Elcock, D. (Environmental Science Division)

    2011-08-03

    ), and with the local political organizations that can influence decisions regarding the use of the alternative source. Often a plan to use reclaimed water will work only if local politics and power plant goals converge. Even then, lengthy negotiations are often needed for the plans to come to fruition. (3) Regulatory requirements for planning and developing associated infrastructure such as pipelines, storage facilities, and back-up supplies that can require numerous approvals, permits, and public participation, all of which can create delays and increased costs. (4) Permitting requirements that may be difficult to meet, such as load-based discharge limits for wastewater or air emissions limitations for particulate matter (which will be in the mist of cooling towers that use reclaimed water high in dissolved solids). (5) Finding discharge options for cooling tower blowdown of reclaimed water that are acceptable to permitting authorities. Constituents in this wastewater can limit options for discharge. For example, discharge to rivers requires National Pollutant Discharge Elimination System (NPDES) permits whose limits may be difficult to meet, and underground injection can be limited because many potential injection sites have already been claimed for disposal of produced waters from oil and gas wells or waters associated with gas shale extraction. (6) Potential liabilities associated with using alternative sources. A power plant can be liable for damages associated with leaks from reclaimed water conveyance systems or storage areas, or with mine water that has been contaminated by unscrupulous drillers that is subsequently discharged by the power plant. (7) Community concerns that include, but are not limited to, increased saltwater drift on farmers fields; the possibility that the reclaimed water will contaminate local drinking water aquifers; determining the 'best' use of WWTP effluent; and potential health concerns associated with emissions from the

  20. Recovery Act: Innovative CO2 Sequestration from Flue Gas Using Industrial Sources and Innovative Concept for Beneficial CO2 Use

    Energy Technology Data Exchange (ETDEWEB)

    Dando, Neal; Gershenzon, Mike; Ghosh, Rajat

    2012-07-31

    field testing of a biomimetic in-duct scrubbing system for the capture of gaseous CO2 coupled with sequestration of captured carbon by carbonation of alkaline industrial wastes. The Phase 2 project, reported on here, combined efforts in enzyme development, scrubber optimization, and sequestrant evaluations to perform an economic feasibility study of technology deployment. The optimization of carbonic anhydrase (CA) enzyme reactivity and stability are critical steps in deployment of this technology. A variety of CA enzyme variants were evaluated for reactivity and stability in both bench scale and in laboratory pilot scale testing to determine current limits in enzyme performance. Optimization of scrubber design allowed for improved process economics while maintaining desired capture efficiencies. A range of configurations, materials, and operating conditions were examined at the Alcoa Technical Center on a pilot scale scrubber. This work indicated that a cross current flow utilizing a specialized gas-liquid contactor offered the lowest system operating energy. Various industrial waste materials were evaluated as sources of alkalinity for the scrubber feed solution and as sources of calcium for precipitation of carbonate. Solids were mixed with a simulated sodium bicarbonate scrubber blowdown to comparatively examine reactivity. Supernatant solutions and post-test solids were analyzed to quantify and model the sequestration reactions. The best performing solids were found to sequester between 2.3 and 2.9 moles of CO2 per kg of dry solid in 1-4 hours of reaction time. These best performing solids were cement kiln dust, circulating dry scrubber ash, and spray dryer absorber ash. A techno-economic analysis was performed to evaluate the commercial viability of the proposed carbon capture and sequestration process in full-scale at an aluminum smelter and a refinery location. For both cases the in-duct scrubber technology was compared to traditional amine- based capture

  1. An Innovative System for the Efficient and Effective Treatment of Non-Traditional Waters for Reuse in Thermoelectric Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    John Rodgers; James Castle

    2008-08-31

    This study assessed opportunities for improving water quality associated with coal-fired power generation including the use of non-traditional waters for cooling, innovative technology for recovering and reusing water within power plants, novel approaches for the removal of trace inorganic compounds from ash pond effluents, and novel approaches for removing biocides from cooling tower blowdown. This research evaluated specifically designed pilot-scale constructed wetland systems for treatment of targeted constituents in non-traditional waters for reuse in thermoelectric power generation and other purposes. The overall objective of this project was to decrease targeted constituents in non-traditional waters to achieve reuse criteria or discharge limitations established by the National Pollutant Discharge Elimination System (NPDES) and Clean Water Act (CWA). The six original project objectives were completed, and results are presented in this final technical report. These objectives included identification of targeted constituents for treatment in four non-traditional water sources, determination of reuse or discharge criteria for treatment, design of constructed wetland treatment systems for these non-traditional waters, and measurement of treatment of targeted constituents in non-traditional waters, as well as determination of the suitability of the treated non-traditional waters for reuse or discharge to receiving aquatic systems. The four non-traditional waters used to accomplish these objectives were ash basin water, cooling water, flue gas desulfurization (FGD) water, and produced water. The contaminants of concern identified in ash basin waters were arsenic, chromium, copper, mercury, selenium, and zinc. Contaminants of concern in cooling waters included free oxidants (chlorine, bromine, and peroxides), copper, lead, zinc, pH, and total dissolved solids. FGD waters contained contaminants of concern including arsenic, boron, chlorides, selenium, mercury

  2. Water use in the development and operation of geothermal power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C. E.; Harto, C. B.; Sullivan, J. L.; Wang, M. Q. (Energy Systems); ( EVS)

    2010-09-17

    , reservoir characteristics, and local climate have various effects on elements such as drilling rate, the number of production wells, and production flow rates. Over the life cycle of a geothermal power plant, from construction through 30 years of operation, plant operations is where the vast majority of water consumption occurs. Water consumption refers to the water that is withdrawn from a resource such as a river, lake, or non-geothermal aquifer that is not returned to that resource. For the EGS scenarios, plant operations consume between 0.29 and 0.72 gal/kWh. The binary plant experiences similar operational consumption, at 0.27 gal/kWh. Far less water, just 0.01 gal/kWh, is consumed during operations of the flash plant because geofluid is used for cooling and is not replaced. While the makeup water requirements are far less for a hydrothermal flash plant, the long-term sustainability of the reservoir is less certain due to estimated evaporative losses of 14.5-33% of produced geofluid at operating flash plants. For the hydrothermal flash scenario, the average loss of geofluid due to evaporation, drift, and blowdown is 2.7 gal/kWh. The construction stage requires considerably less water: 0.001 gal/kWh for both the binary and flash plant scenarios and 0.01 gal/kWh for the EGS scenarios. The additional water requirements for the EGS scenarios are caused by a combination of factors, including lower flow rates per well, which increases the total number of wells needed per plant, the assumed well depths, and the hydraulic stimulation required to engineer the reservoir. Water quality results are presented in Chapter 5. The chemical composition of geofluid has important implications for plant operations and the potential environmental impacts of geothermal energy production. An extensive dataset containing more than 53,000 geothermal geochemical data points was compiled and analyzed for general trends and statistics for typical geofluids. Geofluid composition was found to vary

  3. Institutional impediments to using alternative water sources in thermoelectric power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Elcock, D. (Environmental Science Division)

    2011-08-03

    ), and with the local political organizations that can influence decisions regarding the use of the alternative source. Often a plan to use reclaimed water will work only if local politics and power plant goals converge. Even then, lengthy negotiations are often needed for the plans to come to fruition. (3) Regulatory requirements for planning and developing associated infrastructure such as pipelines, storage facilities, and back-up supplies that can require numerous approvals, permits, and public participation, all of which can create delays and increased costs. (4) Permitting requirements that may be difficult to meet, such as load-based discharge limits for wastewater or air emissions limitations for particulate matter (which will be in the mist of cooling towers that use reclaimed water high in dissolved solids). (5) Finding discharge options for cooling tower blowdown of reclaimed water that are acceptable to permitting authorities. Constituents in this wastewater can limit options for discharge. For example, discharge to rivers requires National Pollutant Discharge Elimination System (NPDES) permits whose limits may be difficult to meet, and underground injection can be limited because many potential injection sites have already been claimed for disposal of produced waters from oil and gas wells or waters associated with gas shale extraction. (6) Potential liabilities associated with using alternative sources. A power plant can be liable for damages associated with leaks from reclaimed water conveyance systems or storage areas, or with mine water that has been contaminated by unscrupulous drillers that is subsequently discharged by the power plant. (7) Community concerns that include, but are not limited to, increased saltwater drift on farmers fields; the possibility that the reclaimed water will contaminate local drinking water aquifers; determining the 'best' use of WWTP effluent; and potential health concerns associated with emissions from the

  4. Water use in the development and operation of geothermal power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C. E.; Harto, C. B.; Sullivan, J. L.; Wang, M. Q. (Energy Systems); ( EVS)

    2010-09-17

    , reservoir characteristics, and local climate have various effects on elements such as drilling rate, the number of production wells, and production flow rates. Over the life cycle of a geothermal power plant, from construction through 30 years of operation, plant operations is where the vast majority of water consumption occurs. Water consumption refers to the water that is withdrawn from a resource such as a river, lake, or non-geothermal aquifer that is not returned to that resource. For the EGS scenarios, plant operations consume between 0.29 and 0.72 gal/kWh. The binary plant experiences similar operational consumption, at 0.27 gal/kWh. Far less water, just 0.01 gal/kWh, is consumed during operations of the flash plant because geofluid is used for cooling and is not replaced. While the makeup water requirements are far less for a hydrothermal flash plant, the long-term sustainability of the reservoir is less certain due to estimated evaporative losses of 14.5-33% of produced geofluid at operating flash plants. For the hydrothermal flash scenario, the average loss of geofluid due to evaporation, drift, and blowdown is 2.7 gal/kWh. The construction stage requires considerably less water: 0.001 gal/kWh for both the binary and flash plant scenarios and 0.01 gal/kWh for the EGS scenarios. The additional water requirements for the EGS scenarios are caused by a combination of factors, including lower flow rates per well, which increases the total number of wells needed per plant, the assumed well depths, and the hydraulic stimulation required to engineer the reservoir. Water quality results are presented in Chapter 5. The chemical composition of geofluid has important implications for plant operations and the potential environmental impacts of geothermal energy production. An extensive dataset containing more than 53,000 geothermal geochemical data points was compiled and analyzed for general trends and statistics for typical geofluids. Geofluid composition was found to vary

  5. A Synergistic Combination of Advanced Separation and Chemical Scale Inhibitor Technologies for Efficient Use of Imparied Water As Cooling Water in Coal-based Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Jasbir Gill

    2010-08-30

    commercial product commonly used for silica/silicate control. Additional pilot cooling tower testing confirmed the bench study. We also developed a molecule to inhibit calcium carbonate precipitation and calcium sulfate precipitation at high supersaturations. During Phase 3, a long-term test of the EDI system and scale inhibitors was done at Nalco's cooling tower water testing facility, producing 850 gallons of high purity water (90+% salt removal) at a rate of 220 L/day. The EDI system's performance was stable when the salt concentration in the concentrate compartment (i.e. the EDI waste stream) was controlled and a CIP was done after every 48 hours of operation time. A combination of EDI and scale inhibitors completely eliminated blowdown discharge from the Pilot cooling Tower. The only water-consumption came from evaporation, CIP and EDI concentrate. Silica Inhibitor was evaluated in the field at a western coal fired power plant.

  6. Control of supersonic axisymmetric base flows using passive splitter plates and pulsed plasma actuators

    Science.gov (United States)

    Reedy, Todd Mitchell

    An experimental investigation evaluating the effects of flow control on the near-wake downstream of a blunt-based axisymmetric body in supersonic flow has been conducted. To better understand and control the physical phenomena that govern these massively separated high-speed flows, this research examined both passive and active flow-control methodologies designed to alter the stability characteristics and structure of the near-wake. The passive control investigation consisted of inserting splitter plates into the recirculation region. The active control technique utilized energy deposition from multiple electric-arc plasma discharges placed around the base. The flow-control authority of both methodologies was evaluated with experimental diagnostics including particle image velocimetry, schlieren photography, surface flow visualization, pressure-sensitive paint, and discrete surface pressure measurements. Using a blowdown-type wind tunnel reconstructed specifically for these studies, baseline axisymmetric experiments without control were conducted for a nominal approach Mach number of 2.5. In addition to traditional base pressure measurements, mean velocity and turbulence quantities were acquired using two-component, planar particle image velocimetry. As a result, substantial insight was gained regarding the time-averaged and instantaneous near-wake flow fields. This dataset will supplement the previous benchmark point-wise laser Doppler velocimetry data of Herrin and Dutton (1994) for comparison with new computational predictive techniques. Next, experiments were conducted to study the effects of passive triangular splitter plates placed in the recirculation region behind a blunt-based axisymmetric body. By dividing the near-wake into 1/2, 1/3, and 1/4 cylindrical regions, the time-averaged base pressure distribution, time-series pressure fluctuations, and presumably the stability characteristics were altered. While the spatial base pressure distribution was

  7. Experimental study of choking flow of water at supercritical conditions

    Science.gov (United States)

    Muftuoglu, Altan

    Future nuclear reactors will operate at a coolant pressure close to 25 MPa and at outlet temperatures ranging from 500°C to 625°C. As a result, the outlet flow enthalpy in future Supercritical Water-Cooled Reactors (SCWR) will be much higher than those of actual ones which can increase overall nuclear plant efficiencies up to 48%. However, under such flow conditions, the thermal-hydraulic behavior of supercritical water is not fully known, e.g., pressure drop, forced convection and heat transfer deterioration, critical and blowdown flow rate, etc. Up to now, only a very limited number of studies have been performed under supercritical conditions. Moreover, these studies are conducted at conditions that are not representative of future SCWRs. In addition, existing choked flow data have been collected from experiments at atmospheric discharge pressure conditions and in most cases by using working fluids different than water which constrain researchers to analyze the data correctly. In particular, the knowledge of critical (choked) discharge of supercritical fluids is mandatory to perform nuclear reactor safety analyses and to design key mechanical components (e.g., control and safety relief valves, etc.). Hence, an experimental supercritical water facility has been built at Ecole Polytechnique de Montreal which allows researchers to perform choking flow experiments under supercritical conditions. The facility can also be used to carry out heat transfer and pressure drop experiments under supercritical conditions. In this thesis, we present the results obtained at this facility using a test section that contains a 1 mm inside diameter, 3.17 mm long orifice plate with sharp edges. Thus, 545 choking flow of water data points are obtained under supercritical conditions for flow pressures ranging from 22.1 MPa to 32.1 MPa, flow temperatures ranging from 50°C to 502°C and for discharge pressures from 0.1 MPa to 3.6 MPa. Obtained data are compared with the data given in

  8. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    ranging from 4 to 21 bar with three different static inventories of non-condensable gas. Condensation and heat transfer rates were evaluated employing several methods, notably from measured temperature gradients in the HTP as well as measured condensate formation rates. A detailed mass and energy accounting was used to assess the various measurement methods and to support simplifying assumptions required for the analysis. Condensation heat fluxes and heat transfer coefficients are calculated and presented as a function of pressure to satisfy the objectives of this investigation. The major conclusions for those tests are summarized below: (1) In the steam blow-down tests, the initial condensation heat transfer process involves the heating-up of the containment heat transfer plate. An inverse heat conduction model was developed to capture the rapid transient transfer characteristics, and the analysis method is applicable to SMR safety analysis. (2) The average condensation heat transfer coefficients for different pressure conditions and non-condensable gas mass fractions were obtained from the integral test facility, through the measurements of the heat conduction rate across the containment heat transfer plate, and from the water condensation rates measurement based on the total energy balance equation. 15 (3) The test results using the measured HTP wall temperatures are considerably lower than popular condensation models would predict mainly due to the side wall conduction effects in the existing MASLWR integral test facility. The data revealed the detailed heat transfer characteristics of the model containment, important to the SMR safety analysis and the validation of associated evaluation model. However this approach, unlike separate effect tests, cannot isolate the condensation heat transfer coefficient over the containment wall, and therefore is not suitable for the assessment of the condensation heat transfer coefficient against system pressure and noncondensable